Abstract Presentations PODIUM PRESENTATIONS | THURSDAY, JULY 11, 2013 | VERSAILLES I & II
TIME
TITLE
LAST NAME
AWARD ELIGIBIE
8:30 AM
BIOMECHANICAL ANALYSIS OF A FATIGUE PROTOCOL USING A
WEIGHTED SLED: EFFECTS ON PERFORMANCE MEASURES
NEWELL
MASTERS
8:45 AM
CHANGES IN MEDIAL GASTROCNEMIUS MUSCLE-TENDON
INTERACTION FOLLOWING 8 WEEKS OF RESISTANCE TRAINING
MCMAHON
DOCTORAL
9:00 AM
EFFECTS OF FATIGUE FROM RESISTANCE TRAINING
ON BARBELL BACK SQUAT BIOMECHANICS
HOOPER
DOCTORAL
9:15 AM
MONITORING NEUROMUSCULAR FATIGUE AND RECOVERY
IN SEMI-PROFESSIONAL RUGBY UNION PLAYERS
GILL
9:30 AM
POWER-LOAD AND VELOCITY-LOAD CURVES: A COMPARISON
OF TWO WEIGHT ROOM TESTING MODALITIES
LANE
9:45 AM
RELIABILITY OF A YOUTH BASEBALL AND TEE BALL HITTING SCALE
WALSH
10:00 AM
THE EFFECT OF TRAINING STATUS AND FATIGUE ON
MUSCLE LENGTH CHANGE DURING JUMPING
PAUL
10:15 AM
THE EFFECTS OF REACTIVE NEUROMUSCULAR TRAINING
VERSUS TRADITIONAL HIP ABDUCTOR EXERCISE ON KNEE
KINETICS IN WOMEN DURING A DROP JUMP LANDING
LYNN
DOCTORAL
MASTERS
PODIUM PRESENTATIONS | FRIDAY, JULY 12, 2013 | VERSAILLES I & II
TIME
TITLE
LAST NAME AWARD ELIGIBLE
8:30 AM
AEROBIC CAPACITY AND MUSCULAR ENDURANCE IMPROVEMENTS WITH
FOUR WEEKS OF BATTLING ROPE HIGH INTENSITY INTERVAL TRAINING
MCAUSLAN
MASTERS
8:45 AM
RELIABILITY AND VALIDITY OF A NOVEL FIELD-BASED HAMSTRING
STRENGTH TEST FOR ASSOCIATION SOCCER PLAYERS:
IMPLICATIONS FOR PREVENTING HAMSTRING INJURIES
LEE
DOCTORAL
9:00 AM
THE INFLUENCE OF AGE ON PASSIVE STIFFNESS
OF THE PLANTAR FLEXOR MUSCLES
SOBOLEWSKI
DOCTORAL
9:15 AM
12 WEEKS OF ORAL ATP SUPPLEMENTATION INCREASES
STRENGTH, POWER, AND LEAN BODY MASS
JOY
MASTERS
9:30 AM
COMPARISONS OF ACUTE NEUROMUSCULAR FATIGUE IN MAXIMAL
EFFORT STRENGTH TRAINING USING POWERLIFTS
THEILEN
9:45 AM
THE EFFECTS OF A CORE STRENGTH TRAINING PROGRAM ON FIELD
TESTING PERFORMANCE OUTCOMES IN JUNIOR ELITE SURF ATHLETES
AXEL
MASTERS
10:00 AM
HITTING A MOVING TARGET: EFFECTS OF PHYSIOLOGICAL STRESS ON
ACCURACY AND RECALL IN POLICE FIREARMS TRAINING
UNRUH
MASTERS
10:15 AM
TRENDS FROM NFL COMBINE DATA MAY PREDICT PERFORMANCE
VALUES OF FUTURE NFL DRAFT PICKS
LEITING
DOCTORAL
10:30 AM
LOWER-BODY STRENGTH AND POWER INFLUENCE
PERFORMANCE IN CHANGE OF DIRECTION TASKS
BOURGEOIS
MASTERS
10:45 AM
STRENGTH AS A PREDICTOR OF THE MAGNITUDE OF
ADAPTATION FROM POWER TRAINING
BREM
MASTERS
11:00 AM
SEGMENTAL CHANGES IN FAT AND SUBCUTANEOUS ADIPOSE TISSUE
AFTER A RAPID WEIGHT LOSS INTERVENTION IN WOMEN
MOON
11:15 AM
THE RELATIONSHIP BETWEEN FUNCTIONAL MOVEMENT SCREEN
SCORES AND TEAM SPORT-SPECIFIC TESTS IN ATHLETES
LOCKIE
PODIUM PRESENTATIONS | SATURDAY, JULY 13, 2013 | VERSAILLES I & II
TIME
TITLE
LAST NAME
8:30 AM
EFFECT OF LADDER CLIMBING ON REGIONAL ANTERIOR PITUITARY
IMMUNOREACTIVE GROWTH HORMONE RELEASE IN MALE RATS
KRAEMER
8:45 AM
THE RELIABILITY OF ISOMETRIC FORCE-TIME VARIABLES COLLECTED
ON A PORTABLE MID-THIGH PULL TESTING DEVICE
HAFF
9:00 AM
COMPARATIVE GONIOMETRY-DERIVED Q-ANGLES FOR
RELAXED VS. CONTRACTED QUADRICEPS FEMORIS MUSCLES
WEISS
9:15 AM
RELATIONSHIP BETWEEN RATING OF PERCEIVED EXERTION,
RESISTANCE EXERCISE INTENSITY, AND FATIGUE
VASQUEZ
9:30 AM
RELATIONSHIP BETWEEN SQUAT STRENGTH AND KNEE
POSITION DURING DROP JUMP LANDINGS
GOODMAN
9:45 AM
QUANTIFICATION OF UNLOADING FORCE AND INFLUENCE ON
POWER OUTPUT AND IMPULSE DURING JUMPING
ALLEY
10:00 AM
RELATIONSHIP BETWEEN SQUAT STRENGTH AND STATIC,
COUNTERMOVEMENT AND DROP JUMP PERFORMANCE
KIJOWSKI
10:15 AM
EFFECTS OF SHORT-TERM RESISTANCE TRAINING AND SUBSEQUENT
DETRAINING ON CONTRALATERAL STRENGTH
COSTA
10:30 AM
THE EFFECT OF INITIATING A STRENGTH PROGRAM ON
LOWER BODY SPEED STRENGTH IN ELITE SURFERS
SHEPPARD
10:45 AM
EFFECT OF WARM-UP DEVICES ON BAT VELOCITY AND PERCEPTION OF
HEAVINESS AND SPEED OF SWING OF COLLEGIATE BASEBALL PLAYERS
SZYMANSKI
11:00 AM
IS THERE A PACING STRATEGY DURING A 505 CHANGE OF
DIRECTION TEST IN ADOLESCENTS?
NIMPHIUS
11:15 AM
THE COMBINED EFFECTS OF EXERCISE, DIET, AND A
MULTI-INGREDIENT DIETARY SUPPLEMENT ON BODY COMPOSITION
AND ADIPOKINE CHANGES IN OVERWEIGHT ADULTS
ARENT
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Thursday, July 11, 2013, 8:30 AM - 8:45 AM
BIOMECHANICAL ANALYSIS OF A FATIGUE PROTOCOL USING A WEIGHTED
SLED: EFFECTS ON PERFORMANCE MEASURES
S. Newell1, N. Fox2, A. C. Fry3, N. Moodie4, D. Wassom5
The University of Kansas, Lawrence, KS, 2Dynamic Athletics Research Institute,
Overland Park, KS, 3The University of Kansas, Human Performance Laboratory,
Lawrence, KS, 4Rockhurst University, 5Dynamic Athletics
1
*Award Eligible - Outstanding Master’s Student Podium Presentation
PURPOSE: To introduce a novel fatigue protocol using a weighted sled and to
evaluate biomechanical performance changes. METHODS: Four recreationally
trained male subjects (age 19±2yr, mass 74.5±8.5kg) and one female subject
(age 27yr, mass 61kg) participated in a pilot fatigue protocol utilizing a weighted
push sled. Subjects completed a resistance exercise bout consisting of 8 all-out
sprints pushing a sled for 40yds with 30lbs of external weight added. Sets were
broken up to allow for testing. A 3D Markerless motion capture system was used
to collect the biomechanical data. This technology was utilized to decrease set
up and testing time per athlete. During the weighted sled sets, time was used
to determine performance. For the biomechanical testing, jump height, rate of
force development, and net joint torques were used to measure performance.
RESULTS: Each weighted sled push showed a significant time reduction (p>0.05)
at every push when compared to the first. Average percent drop from first through
eighth was (6%, 8%, 16%, 18%, 23%, 22%, 30%). Box Jump max height achieved
also showed a significant reduction (p>0.05) found at every set of box jumps
compared to the first set. Average percent drop from the first set through the
fourth set was (6%, 8%, 13%, 15%). Range of motion at the hips, knees, and ankles
at max loading during the box jumps did not significantly change (p>0.05) with
drops in performance. Average percent change from the first set through the
forth was (Hips: 3%, 3%, 5%, 4%; Knees: 2%, 2%, 4%, 4%; Ankles: 1%, 2%, 2%, 2%).
Max joint torques at the hips, knees, and ankles during the box jumps changed
significantly (p>.05) with drops in performance. When comparing joint torques
from the first sets to just the fourth sets there is a 51% decrease at the hips, 54%
increase at the knees, and 51% increase at the ankles. Rate of force development
during the box jumps did significantly change (p>.05) with drops in performance.
When comparing pre testing box jumps to post testing box jumps there was a 58%
drop in rate of force development. CONCLUSION: A weighted sled has the ability
to drastically induce fatigue. Rate of force development and net joint torques
changed significantly during the protocol. These results suggest that as the hips
fatigue other joints over compensate, but do not provide the same performance.
Further research needs to be done to track more biomechanical markers as well as
combined acute physiological responses. PRACTICAL APPLICATIONS: Since the
sled allows the athlete to go through a normal range of motion it produces more
natural movement patterns thus transferring the performance enhancement with
less stress on the joints. With this study we now have a better idea of progressive
compensation techniques with fatigue. This information could lead to more
effective uses for the weighted sled in the future.
Thursday, July 11, 2013, 8:45 AM - 9:00 AM
CHANGES IN MEDIAL GASTROCNEMIUS MUSCLE-TENDON INTERACTION
FOLLOWING 8 WEEKS OF RESISTANCE TRAINING
J. J. McMahon1, S. J. Pearson1, P. Comfort1
1
University of Salford
*Award Eligible - Outstanding Doctoral Student Podium Presentation
It is well documented that muscle and tendon adapts to resistance training
by increasing strength, size and stiffness. The effect of such adaptions on
subsequent muscle-tendon interaction during functional performance, however,
has not been examined. PURPOSE: To determine the effects of loading on medial
gastrocnemius (MG) muscle-tendon interaction in order to inform resistance
training practice. METHODS: Resistance trained males (n=11, 27.0 ± 8.4 years,
180.8 ± 5.8 cm, 86.3 ± 10.2 kg) performed three single-leg hopping trials (each
lasting 15 seconds) on an inclined sledge at 2.0, 2.5 and 3.0 Hz in a randomized
and balanced order. Three-dimensional motion analysis, ultrasonography of MG
and ground reaction forces were collected. For each trial, five consecutive hops
performed within ±5% of the prescribed frequencies were analyzed. Sagittal plane
joint angles and joint moments were determined via a combination of motion
data, force data and inverse dynamics. Ankle joint stiffness was calculated as
the ratio of peak joint moment (relative to body mass) to peak joint angular
displacement. MG muscle-tendon unit (MTU) length was determined as a function
of shank segment length and joint angle data. MG muscle length was calculated as
fascicle length multiplied by the cosine of the pennation angle. MG tendon length
was determined by subtracting MG muscle length from MG MTU length. The
elongation and shortening phase for each component of the MTU was determined
based on the peak MTU elongation during the ground contact phase of each hop.
One repetition maximum (1-RM) calf raise was determined on a separate day.
Participants performed four sets of 12 repetitions of the calf raise with 67% of
1-RM, twice per week for eight weeks before being retested. Dependent t-tests
were used to compare pre- and post-training data (p=0.05). RESULTS: 1-RM calf
raise significantly increased from 82.0 ± 16.4 kg to 93.5 ± 23.0 kg (p<0.05). There
were no significant post-training changes in MG muscle-tendon interaction at 2.0
Hz; in contrast there was a significant decrease in MG muscle elongation at both
2.5 Hz (-0.6 ± -0.2 mm vs. -1.4 ± -0.2 mm, p<0.05) and 3.0 Hz (-1.3 ± -0.4 mm vs.
-2.4 ± -0.6 mm, p<0.05). Equally, there was a significant (p<0.05) increase in MG
tendon elongation at 2.5 Hz (15.1 ± 1.7 mm vs. 18.2 ± 3.9 mm) and 3.0 Hz (11.0 ± 1.9
mm vs. 13.7 ± 3.0 mm). This was accompanied by a significant (p<0.05) increase
MG MTU elongation at both frequencies (2.5 Hz: 14.6 ± 2.0 mm vs. 16.9 ± 4.1 mm;
3.0 Hz: 9.8 ± 2.1 mm vs. 11.4 ± 3.1 mm), leading to a significant decrease in ankle
joint stiffness at both 2.5 Hz (0.29 ± 0.05 Nm/kg/deg vs. 0.25 ± 0.04 Nm/kg/deg,
p<0.01) and 3.0 Hz (0.40 ± 0.07 Nm/kg/deg vs. 0.36 ± 0.08 Nm/kg/deg, p<0.05).
There were no significant changes in MG muscle, tendon or MTU shortening at
any frequency. CONCLUSIONS: Despite post-training increases in muscle strength,
ankle joint stiffness decreased when hopping at 2.5 and 3.0 Hz due to an increase
in MG tendon elongation. PRACTICAL APPLICATIONS: Short-term resistance
training leads to a disproportionate increase in muscle strength in comparison to
tendon stiffness, resulting in a greater reliance on the series-elastic component
during stretch-shortening cycle movements performed at higher velocities.
ACKNOWLEDGEMENTS: This study was funded by the NSCA Foundation.
Thursday, July 11, 2013, 9:00 AM - 9:15 AM
EFFECTS OF FATIGUE FROM RESISTANCE TRAINING ON BARBELL
BACK SQUAT BIOMECHANICS
D. Hooper1, T. Szivak1, B. Comstock1, C. Dunn-Lewis1, J. Apicella1, D. Looney1,
S. Flanagan1, B. Creighton1, H. Luk1, W. J. Kraemer1
1
University of Connecticut
*Award Eligible - Outstanding Doctoral Student Podium Presentation
Purpose: Exhaustive resistance training programs that have been previously
referred to as ‘extreme conditioning protocols’ have increased in popularity in
military and civilian populations in recent years. However, these programs have
also been associated with increases in injury. As both cardiovascular and local
muscular fatigue have been shown to result in reduced proprioception, the
combination of both stimuli in these ‘extreme conditioning protocols’ could be
a concern. Further, when these programs are performed with higher loads as
well as with complex movements, the possibility of performing such lifts with
poor technique could certainly result in injury. Therefore, the purpose of this
study is to assess the alterations in movement patterns that result from ‘extreme
conditioning protocols’ and to evaluate if these changes are the mechanism of
increased injury rates in such programs. Methods: 12 men (age 24 ± 4.2 years,
height 173.1 ± 3.6 cm, weight 76.9 ± 7.8 Kg, body fat percentage 9.0 ± 2.2) and 13
women (age 24.5 ± 3.8 years, height 166.9 ± 8.5 cm, weight 66.1 ± 9.2 Kg, body
fat percentage 18.6 ± 4.0) with at least 6 months of resistance training experience
performed a resistance training workout. The resistance training protocol was
designed to create as much fatigue as possible in order to study a near worst case
scenario for ‘extreme conditioning protocols’. 75% 1RM load was used for each
of the three lifts; back squat, bench press and deadlift. Subjects began with 10
repetitions of each lift and then reduced the number consecutively by 1 until they
reached only 1 repetition. Subjects were instructed to perform all of the repetitions
as quickly as possible. If the prescribed repetitions for a set were not able to
be performed in one single set (i.e. rest was taken mid-set), the following set was
performed at 5% RM less (i.e. 70%). The subjects were instructed to perform the
routine with as little load reduction as possible. In order to analyze the impact
that fatigue has on movement patterns, a two-dimensional analysis of the barbell
back squat was performed using Dartfish (Fribourg, Switzerland). Plasma lactate
was measured as an indicator of fatigue via blood drawn from an indwelling
catheter immediately before and after the workout. Results: Over the course of
the workout knee angle significantly (p ≤ 0.05) changed for both men (early 97.4
± 6.8 vs. late 90.4 ± 5.6) and women (early 103.9 ± 8.1 vs. late 91.7 ± 10.0). Also,
hip angle significantly (p ≤ 0.05) changed for both men (early 86.7 ± 15.9 vs. late
116.8 ± 72.8) and women (early 87.6 ± 9.1 vs. late 101.5 ± 8.6). Mean blood lactate
for men before the protocol (Pre) was 1.48±0.30 mmol●L-1 and immediately
following the workout (IP) was 14.21±2.19 mmol●L-1. Mean (Pre) blood lactate for
women was 1.44±0.42 mmol●L-1 and (IP) was 10.06±2.50 mmol●L-1. Conclusions:
These changes serve as a potential avenue to explain the increased injuries seen
in ‘extreme conditioning protocols’. A potential cause for said increased injury
risk could be that exercises are being performed with changes in technique, as
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
fatigue has been associated with reductions in proprioception. This study showed
that alterations in technique do occur in ‘extreme conditioning protocols’ but a
long term study would be required to see if these changes are contributing to
increased injury. Ultimately, this study has documented the changes that occur
in an exhaustive resistance training program that represents a near worst case
scenario. Practical Applications: If movement patterns change during a resistance
exercise, particularly under heavy loads, it seems in the interest of athlete safety
that this workout design is performed with less technical exercises (such as
resistance machine exercises) to keep potential injury risk at a minimum while still
seeing the positive adaptations associated with such program design.
Thursday, July 11, 2013, 9:15 AM - 9:30 AM
MONITORING NEUROMUSCULAR FATIGUE AND RECOVERY IN
SEMI-PROFESSIONAL RUGBY UNION PLAYERS
N. Gill1, D. McMaster2, D. Smart3, J. Cronin4, M. McGuigan5
1
All Blacks - New Zealand Rugby Union, 2Sports Performance Research
Institute New Zealand, 3Hight Performance Sport New Zealand, 4Sports
Performance Research Institute New Zealand - AUT University, 5AUT University
PURPOSE: In elite rugby, the rigors and demands of a match and competition
can have acute and accumulative effects on neuromuscular performance; various
monitoring methods can be utilized to detect system fatigue and recovery.
Vertical jump peak power is commonly used track and quantify neuromuscular
fatigue and recovery following rugby matches. Few studies have fully assessed
the accumulative effects of a rugby competition on vertical jump performance;
furthermore no prior research has monitored the changes in the peak power
derivatives (i.e. force at peak power and velocity at peak power) and their
contribution to fatigue and recovery. The aim of the current study was to track
the time course changes in vertical jump peak power, force at peak power and
velocity at peak power to monitor the amount of acute and chronic neuromuscular
fatigue and the weekly recovery rates in semi-professional rugby union players
throughout a competitive season. METHODS: Vertical jump performance of
eighteen semi-professional rugby union players (age = 23.9 ± 2.9 yr; height =
184.4 ± 7.2 cm; body mass = 103.1 ± 12.4 kg) was monitored at regular time points
between games(pre [58 ± 2 hr] and post [41 ± 10 hr]) across a nine week period.
Two body mass countermovement jumps (CMJ) and a portable force plate were
used to measure peak power, velocity at peak power and force at peak power.
RESULTS: There were small decreases in post-game peak power (-2.3%) and
velocity at peak power (-2.7%) in comparison to baseline values; while differences
between baseline and pre-game were trivial (<1.0%). Small increases in CMJ peak
power and velocity at peak power (2.9 - 3.7 %) from post-game to pre-game
were observed; whereas the pre- vs. post- game force at peak power changes
were trivial (-0.5%; ES = 0.08). There were small increases in peak power (2.4 ±
2.6%) and velocity at peak power (5.9 ± 4.1%) and small decreases in CMJ force
at peak power (-3.7%; ±4.0%) from the first two weeks of competition to the last
two weeks. Large and very large correlations were observed between velocity at
peak power (r = 0.62), peak power (r = 0.72) and the number of hours post-match
jump testing took place. There were also moderate correlations (r = 0.47 – 0.52)
between enhanced pre-game CMJ performance and match outcome (expressed
as a positive or negative value based on score differential). CONCLUSION: The
results suggest that fluctuations in peak power were most-likely due to decreases
and increases in velocity and not force, therefore velocity produced at peak power
appears to be the limiting factor for assessing peak power decay and recovery
rates. Neuromuscular performance (peak power) may be diminished for up to 110
hr post match from a neuromuscular fatigued state. PRACTICAL APPLICATIONS:
The rate/amount of post-game fatigue (i.e. decrease in peak power and velocity
at peak power) in proportion to the week prior and baseline may be used to guide
daily and weekly training loads throughout the season. Peak power output can
be maintained and under the right training stimulus even improved throughout
a competitive season. ACKNOWLEDGEMENTS: The investigators would like to
thank the North Harbour Rugby Union staff and players for their support of and
cooperation on this project. Thursday, July 11, 2013, 9:30 AM - 9:45 AM
POWER-LOAD AND VELOCITY-LOAD CURVES: A COMPARISON OF TWO
WEIGHT ROOM TESTING MODALITIES
M. T. Lane1, A. C. Fry1, J. Weir2, T. J. Herda3, M. Andre2,
A. Hudy2, G. Cain2, L. Bradford2
1
The University of Kansas, Human Performance Laboratory, Lawrence, KS,
2
University of Kansas, 3University of Kansas /
Biomechanics Laboratory, Lawrence, KS
*Award Eligible - Outstanding Doctoral Student Podium Presentation
Many strength and conditioning professionals prescribe resistance training based
in part on power and velocity characteristics of the individual. Currently several
testing modalities are available for use in the training facility. Purpose: To compare
tether-based and 3-D camera-based external dynamometers for determining
power-load and velocity-load curves for the barbell speed squat exercise.
Methods: Twenty resistance-trained collegiate student-athletes participated in
this study (8 female 12 male). Each athlete performed one set of three repetitions
at loads of 30, 40, 50, 60, 70, 80, and 90% of their 1 repetition maximum (1 RM)
for the barbell parallel speed squat exercise. Each repetition was recorded with
both a Weightlifting Analyzer Tendo device (Fitrodyne; Bratislava, Slovakia) and
an EliteForm PowerTracker system (EliteForm; Lincoln, Nebraska). The Tendo
dynamometer uses a nylon tether attached to the barbell, while the EliteForm
PowerTracker uses 3-D video cameras to record barbell movement. The repetition
with the highest mean power for each set was used for data analyses. Using mean
power data and 2° polynomial regressions, a power-load curve was calculated for
each subject. From these curves, maximum power and barbell load at maximum
power were determined. Using mean velocity data and linear regressions, a
velocity-load curve was also determined for each subject. Comparisons of data
from both dynamometers used paired t-tests (α<0.05) corrected using the HolmBonferonni method. Where appropriate, Cohen’s D effect sizes were calculated.
Results: Estimated maximum power was significantly different between the two
dynamometers (Tendo=676.0±213.4 W, EliteForm=654.1±204.2), but the effect size
was extremely small (D=0.09). Barbell loads at estimated maximum power were
similar (Tendo=83.0±20.8 kg, EliteForm=84.3±22.0 kg). No significant differences
were reported for any curve variables for either the power-load (1st, 2nd or 3rd
polynomial coefficients) or the velocity-load curves (slope, intercept). Excellent
data fit for all regressions was evident from the r2 values (power-load, Tendo =
0.95, EliteForm = 0.85; velocity-load, Tendo = 0.93, EliteForm = 0.95). Conclusion:
Previous research has examined whether external dynamometers such as used in
the present study provide valid data for barbell exercises. These data demonstrate
the comparability of either testing modality for determining more complex
measures that are useful for the strength and conditioning professional or coach.
Results from the use of 3-D camera technology for these types of measures
results in similar power and velocity values to those derived from tether-based
technology. Practical Application: Use of the Tendo or the EliteForm external
dynamometers will result in comparable power-load or and velocity-load curves
resistance-trained college-aged student-athletes. Acknowledgement: This study
was supported in part by Nebraska Global LLC.
Thursday, July 11, 2013, 9:45 AM - 10:00 AM
RELIABILITY OF A YOUTH BASEBALL AND TEE BALL HITTING SCALE
A. Walsh1, G. G. Haff1, S. Nimphius2
1
Edith Cowan University, 2Centre for Exercise and Sport Science,
Edith Cowan University
*Award Eligible - Outstanding Master’s Student Podium Presentation
Extended age for exit from tee ball to baseball in Australia has led to issues in
the development of key baseball skills. In particular, the development of poor
hitting mechanics seems to be more prevalent as a result of this slow transition.
To allow for assessment and critique of hitting motor competence a hitting scale
was developed using experienced coaches in conjunction with current motor
competence scales for striking skills. The scale was comprised of six criterion
sections addressing the hands, hips, shoulders, coordination of movement and
follow through. PURPOSE: To assess inter and intra rater reliability of a hitting
competency scale in youth tee ball and baseball players. METHODS: Ten male
participants (age: 11.1 ± 2.02 years) with at least one year of prior tee ball or baseball
experience attended three testing sessions. After a baseball specific warm-up,
each participant hit 5 balls off a tee followed by 5 balls from “soft toss” with the
instruction to “hit the ball up the middle”. Each swing was recorded using two
cameras. The rear and side on view video were synced and two coaches used the
hitting scale to assess each swing. Intraclass correlation coefficient and coefficient
of variation with 90% confidence intervals (90%CI) were calculated for inter and
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
intra rater reliability. RESULTS: Inter rater reliability was high (ICC=0.98; 90%CI:
0.94-0.99) with low coefficient of variation (CV=3.5%, CI: 2.9-4.4%) for the tee
and soft toss (ICC = 0.99; 90%CI: 0.97-1.00)(CV = 2.5%; 90%CI: 2.1-3.1%). Further,
intra tester reliability was also high for both tee (ICC = 0.98; 90%CI: 0.95-0.99)(CV
= 6.6%; 90%CI: 5.6-8.3%) and soft toss (ICC = 0.99; 90%CI: 0.98-1.00)(CV = 4.5%;
90%CI: 3.7-5.6%). CONCLUSION: The results demonstrate the hitting scale used
in this study is reliable between sessions and between assessors (or coaches).
Further, the use of either a tee or soft toss to assess hitting competency using this
scale is similarly reliable. PRACTICAL APPLICATIONS: The high reliability between
the sessions and drills demonstrate that the scale is reliable for grading youth
baseball swings. The ability to assess this fundamental skill with a reliable scale
allows coaches to identify areas to improve in the swing and determine progress
of swing mechanics.
Thursday, July 11, 2013, 10:00 AM - 10:15 AM
THE EFFECT OF TRAINING STATUS AND FATIGUE ON MUSCLE LENGTH CHANGE
DURING JUMPING
J. Paul1, J. Alley1, C. Goodman2, L. Vasquez1, C. John3, T. Triplett3,
T. Erickson4, J. McBride2
1
Appalachian State University, 2Appalachian State University/Neuromuscular &
Biomechanics Laboratory, Department of Health, Leisure & Exercise Science,
Boone, NC, 3Appalachian State University, 4Appalachian State
*Award Eligible - Outstanding Master’s Student Podium Presentation
The purpose of this investigation was to utilize a novel technique involving the
insertion of a Fiber Bragg Grading sensor through the patellar tendon to determine
changes in tendon length in a single trained and untrained jumper. Muscle-tendon
unit (MTU) force output and length change during stretch -shortening cycle (SSC)
activities has been investigated but the exact mechanism for optimal function
is still unclear. It has been speculated that MTU function differs between trained
and untrained individuals, thus effecting concentric performance. Fatigue has
also been speculated to decrease concentric performance due to an alteration in
MTU function. PURPOSE: The purpose of this investigation was to determine the
effect of training status on muscle, tendon, and muscle tendon unit length change
during jumping. METHODS: One trained jumper (height = 71in, weight = 82.5kg,
vertical jump 29.5in, age = 22yrs) and one untrained individual (height = 71.2,
weight 74.8 kg, vertical jump 25.5in, age 19yrs) were recruited. They both reported
to the laboratory one time for three hours. An optic fiber was inserted through the
patellar tendon and used to determine tendon tension. An ultrasound probe was
attached to the vastus lateralis and used determine muscle length. Each subject
was asked to perform a total of 12 individual counter movement jumps (CMJ), 12
individual static jumps (SJ), 20 sequential CMJ, and 20 sequential SJ. Individual
SJ and CMJ were performed before and after the sequential jumps to determine
changes in MTU function due to fatigue. RESULTS: The trained individual had
a 11% increase in force production, a 26% decrease in patellar tendon length, a
42% increase in muscle fiber length, and a 5.7% increase in jump height. These
results demonstrate the changing function of the MTU during fatigue. The trained
individual had a 4% decrease in force production, a 92% decrease in patellar
tendon length, a 52% decrease in muscle length, and 1.2% decrease in jump height.
The large decrease in patellar tendon length, and decrease in muscle length can
be explained by the shallow depth of the counter movement jump while fatigued.
The ratio of muscle length change to tendon length change in the untrained
individual was greater than the ratio of muscle length change to tendon length
change in the trained individual. This indicates that a trained individual is better
able to maintain muscle length during jumping. CONCLUSION: Fatigue impacts
MTU function by decreasing the muscle’s ability to maintain length. Increasing
change in muscle length and decreasing change in tendon length decreases
concentric performance. PRACTICAL APPLICATION: Jump training may influence
performance by varying the function of the MTU thus future research should focus
on longitudinal study of these variables. ACKNOWLEDGEMENTS: NSCA Senior
Investigator Award.
Thursday, July 11, 2013, 10:15 AM - 10:30 AM
THE EFFECTS OF REACTIVE NEUROMUSCULAR TRAINING VERSUS
TRADITIONAL HIP ABDUCTOR EXERCISE ON KNEE KINETICS IN WOMEN
DURING A DROP JUMP LANDING
S. K. Lynn1, M. Pittman1, B. Hamedani1, G. J. Noffal2, K. Tsang1
1
California State University, Fullerton - Center for Sport Performance Biomechanics Laboratory, 2Center for Sport Performance, California State
University, Fullerton, CA
Purpose: Females experience a higher rate of knee injuries when compared with
males, with the anterior cruciate ligament (ACL) being the most common injured
structure. A noncontact mechanism accounts for approximately 72% of ACL injuries
and these injuries generally occur during dynamic tasks such as landing from a
jump. A large knee abduction moment has been identified as a good predictor of
ACL injury; therefore, the development of exercise programs that can decrease
this abduction moment are warranted. It has been shown that proper functioning
of the hip abductor musculature can help in reducing the frontal plane moments
on the knee. One novel method of training the hip abductors involves using a
proprioceptive technique for isometric stabilization or Reactive Neuromuscular
Training (RNT). Therefore, the purpose of this study is to investigate the effects
of RNT and traditional hip abductor training in females on the abduction moment
at the knee during a drop jump landing task. Methods: Twenty recreationally
trained female subjects (age=22.3±2.5yrs, height=1.66±0.06m, mass=61.4±9.3kg)
completed the study. Following initial testing, they were split into three groups:
Control (C)(n=8), Traditional Hip Abductor Training (THAT)(n=6), and RNT (n=6). Training lasted 8 weeks and subjects performed their exercises 3 times/week. The
THAT group performed side lying hip abductions (clams), while the RNT group did
single leg Romanian deadlifts with a resistance band around their knee pulling it
medially. Subjects were tested pre and post intervention doing a drop jump landing
onto an AMTI force plate as an eight camera motion capture system (Qualisys)
simultaneously tracked retro-reflective markers strapped securely to the sacrum,
thigh, shank and foot. Motion and force data were combined using Visual 3D
(C-Motion Inc.) software to calculate the frontal plane knee joint moments. Mean
peak external knee abduction moments (Nm/kg) were compared between the
C, THAT, and RNT groups using a 2x3 (Pre/Post x Group) mixed-model ANOVA.
Results: Results revealed a significant Pre/Post x Group interaction (p<0.05). Post hoc paired samples T-tests then revealed only the RNT group decreased
their abduction moment following training (p<0.05). Conclusion: RNT training
was able to reduce the knee abduction moment during a drop jump landing task,
while standard hip abduction training (side lying hip abduction) did not. Practical
Applications: RNT training may be a valuable tool to use with those athletes prone
to valgus collapse related injuries (i.e. ACL injury). Using this method of training
to help reduce the abduction moment at the knee would have great potential
applications in rehabilitation and in reducing injury prevalence.
Thursday Posters
Thursday, July 11, 2013, 11:30 AM – 1:00 PM
Poster: 1
THE ACUTE HORMONAL RESPONSE TO THE KETTLEBELL SWING EXERCISE
R. G. Budnar1, J. L. Vingren1, B. K. McFarlin1, A. A. Duplanty1, A. Fernandez1,
M. E. Anderson1, D. W. Hill1
1
University of North Texas
*Award Eligible - Outstanding Master’s Student Poster Presentation
INTRODUCTION: Kettlebell exercises such as the kettlebell swing have recently
been popularized in the strength and conditioning community and have been
shown to improve strength, power, and maximal aerobic power. The acute
hormonal response moderates physiological adaptations to exercise and is
affected by acute program variables such as exercise selection. The appearance
of an acute hormonal increase in response to exercise and the magnitude of the
response are affected by the amount of muscle mass involved. The kettlebell swing
involves a large muscle mass (legs, hips, shoulder, back) and thus might induce a
large acute hormonal response. However, no previous studies have evaluated the
acute hormonal response to the kettlebell swing exercise. PURPOSE: The purpose
of this investigation is to examine the acute hormonal response to a bout of
kettlebell swing exercise. METHODS: Ten healthy men (19-30 y, 23.6 ± 3.5 y, 174.6
± 5.7 cm, 78.7 ± 9.9 kg) who were engaged in resistance training at least twice
per week but were inexperienced with kettlebell swings participated in this study.
Participants were familiarized with the kettlebell swing exercise during an initial
visit. During the subsequent experimental protocol visit, participants performed
12 rounds of 30 seconds of 16-kg kettlebell swings alternated with 30 seconds of
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
rest. Heart rate (HR) and rating of perceived exertion (RPE) were measured at the
end of every round of swings. Fasted blood samples were collected pre-exercise
(PRE), immediately post (IP), 15 minutes post (P15), and 30 minutes post exercise
(P30) and analyzed for total testosterone (TT), growth hormone (GH), cortisol,
and lactate concentrations. RESULTS: Participants completed a total of 227 ± 23
swings (average swings per round: 19 ± 2). HR and RPE increased significantly (P
< 0.05) throughout the exercise protocol. Lactate concentration was significantly
increased at all post exercise time points compared to PRE. TT was significantly
increased at IP compared to PRE. GH was significantly increased at IP, P15, and
P30 compared to PRE. Cortisol was significantly increased at IP and P15 compared
to PRE. CONCLUSION: 12 rounds of 30 seconds of kettlebell swing exercise
induced an acute increase in TT, GH, and cortisol concentrations in resistance
trained men. PRACTICAL APPLICATIONS: A relatively short duration of exercise
(total of 6 minutes of exercise in a 12-minute session) produced an acute increase
in hormones involved in muscle recovery and adaptations. Additionally, this
exercise protocol induced a large increase in HR and lactate concentration. Thus,
the kettlebell swing exercise might provide an effective method for simultaneous
endurance and resistance training. Poster: 2
ACUTE HORMONAL RESPONSES TO SUPER-SLOW OR TRADITIONAL
RESISTANCE EXERCISE IN MEN
A PILOT STUDY
P. R. Dietz1, A. C. Fry1, M. J. Andre1, Z. Graham2, M. T. Lane1
1
The University of Kansas,
Human Performance Laboratory, Lawrence, KS, 2University of Kansas
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Various methods of resistance training have gained in popularity such as superslow resistance exercise (i.e., 10 s concentric and eccentric phases) where
movement velocity is purposely slow. Because of the slow movement, there are
limitations to the loads that can be lifted (e.g., <50% 1 RM). PURPOSE: The purpose
of this project was to determine the acute hormonal responses to traditional and
super-slow resistance exercise protocols in healthy college age men. METHODS:
Three healthy resistance-trained men served as subjects (X±SD; age = 24.7±3.8
yrs, Hgt = 1.79±0.03 m, BW = 96.5±8.4 kg, 1 RM squat = 197.7±6.4 kg, 1 RM bench
press = 140.3±15.0 kg). Each subject performed 3 testing sessions in randomorder; one control session where no exercise was performed, and two different
free weight resistance exercise sessions, a traditional protocol and a super-slow
training protocol. The traditional protocol consisted of 3 x10 at 70% 1 RM loads for
the parallel squat and the bench press exercises. Inter-set rest intervals were 1 min,
with 2 min between exercises. The super slow training protocol consisted of 1x10
at 28% 1 RM loads for the parallel squat and bench press exercises. Inter-set rest
intervals were 1 min, with 2 min between exercises. Serum samples collected from
a superficial antecubital vein 15 min pre exercise (Pre) and 5 min post exercise
(Post) were analyzed for total testosterone, cortisol, and immunoreactive growth
hormone (IR GH;22 kDa). Lactate (HLa) was sampled via finger-stick at the same
times. Serum samples were collected at identical times during the control session.
All testing was performed between 1630-1900 hrs, with times held constant
for each subject to minimize diurnal variations. ELISAs were used to determine
circulating concentrations for each hormone. RESULTS: This study lists the
hormonal responses (X±SD) for each exercise protocol. * indicates > 2 SD different
from pre value; … indicates > 2 SD different from control value. The acute responses
for growth hormone, cortisol, and lactate increased for both protocols; whereas
only the traditional protocol increased testosterone. All sessions were completed
in 9 – 11 min. Volume-loads (reps x wgt.) were 6840.2±625.2 kg for the traditional
session and 895.5±91.7 kg for the super-slow session. CONCLUSIONS: Contrary to
some claims in the lay literature, the super-slow session did not produce greater
hormonal or lactate responses than the traditional resistance exercise session.
Additionally, the super-slow session took approximately the same amount of time
to complete. Due to the small sample size and the exploratory nature of these data,
additional study is warranted to more closely compare endocrine responses to
these two resistance exercise protocols. PRACTICAL APPLICATIONS: Individuals
who want to achieve large acute hormonal increases while training for strength
can use a traditional protocol with heavy loads (e.g., 3 x 10 at 70% 1 RM) and short
rest intervals (1 min inter-set rest).
Poster: 3
THE EFFECT OF DIFFERENT FREQUENCIES OF WHOLE BODY VIBRATION ON
SALIVARY TESTOSTERONE AND CORTISOL LEVELS IN COLLEGE AGED MALES
B. Parker1, R. Wood2, T. Matthews2, V. Paolone2
1
University of Rhode Island, 2Springfield College
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: Hormone levels have been shown to be an important factor in
development of strength, power, and athletic performance. The use of WBV has
been shown to increase testosterone levels and decrease cortisol levels thereby
placing the body in a primarily anabolic state. The purpose of the current study
was to examine the hormonal effects of different frequencies of Whole Body
Vibration (WBV) as measured via salivary testosterone and salivary cortisol levels.
METHOD: Eleven physically active male subjects (20.18 + 1.25 yrs; 84.23 + 18.73
kg) completed the protocol. All subjects completed one accommodation session,
during which the subjects stood on the vibration platform with no stimulus (0
Hz) for 10 1-min bouts with 1-min of rest between each bout for a total of 19 min
on the platform. Unstimulated saliva samples were collected in 1.5 ml aliquots
prior to standing on the platform followed by samples at 0-min Post, 15-min Post,
and 30-min Post. Subjects underwent three additional sessions at a randomly
selected frequency (30 Hz, 40 Hz, or 50 Hz). Collection of saliva was identical for
all subjects at all sessions. A total of two 4 x 4 repeated measures factorial analysis
of variance (ANOVA) was utilized to examine the differences or interactions that
existed for the following dependent variables: salivary testosterone and salivary
cortisol. RESULTS: Mean salivary testosterone level at 50 Hz (160.81 + 4.26 pg/
mL) was significantly (p < .05) lower than mean testosterone at 0 Hz (190.12 +
10.43 pg/mL). Mean salivary cortisol level at 15-min Post WBV (0.37 + 0.06 ug/
dL) and 30-min Post WBV (0.31 + 0.05 ug/dL) was significantly (p < .05) lower
than mean cortisol at baseline (0.45 + 0.06 ug/dL). CONCLUSIONS: In the current
investigation, it was hypothesized that at a higher frequency of WBV, motor unit
recruitment would increase as it would with a progressive overload. This would
result in the recruitment of a greater number of muscle fibers, which would enable
greater hormone-tissue interaction, a precursor to anabolism. Furthermore, it
was hypothesized that as frequency of WBV increased, thereby increasing the
gravitational load, both testosterone and cortisol would increase based on the
increased recruitment of muscle fibers. Perhaps the stimulus of WBV in the
current investigation was not sufficient enough to elicit the hormonal response
one would expect with greater training volume. Because salivary cortisol levels
decreased in the current investigation, the hormonal response to the WBV failed
to produce a general stress response as well as a response commonly seen in
exercise. In addition, the decrease in salivary testosterone levels indicated that
the stimulus provided by WBV in the current study was not sufficient enough
to produce increases in testosterone as would normally occur following a bout
of resistance training. PRACTICAL APPLICATIONS: Vibration training is relatively
new and, therefore, guidelines for WBV exercises and protocols have yet to be
standardized. Further research needs to be conducted to determine the most
effective protocols for this form of training and in the specific arena of athletic
performance toward which the technology is being targeted.
Poster: 4
EFFECTS OF HIGHER AND LOWER RESISTANCE EXERCISE VOLUME ON SERUM
TESOSTERONE AND SKELETAL MUSCLE ANDROGEN RECEPTOR, MYOSTATIN,
AND MGF MRNA EXPRESSION
M. Spillane1, N. Schwarz1, D. Willoughby1
1
Baylor University
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Testosterone (TEST) has shown the ability to augment muscle protein synthesis
through a variety of biochemical and molecular interactions. Higher and lower
volumes of resistance exercise have been demonstrated to differentially elevate
endogenous levels of TEST. As a result, the ability of acute resistance exercise
with higher (HV) and lower volumes (LV) to alter key regulators of skeletal muscle
mass [androgen receptor (AR), myostatin, and mechano growth factor (MGF)]
needs to be elucidated. PURPOSE: To examine the effect resistance exercise with
either HV or LV on serum TEST levels as well as the subsequent effects on skeletal
muscle AR, myostatin, and MGF mRNA expression. METHODS: 9 resistancetrained (a minimum of 3 exercise sessions/wk for 1 yr) men (18-25 yrs) performed
two separate resistance exercise bouts. One bout consisted of a LV routine [lowerbody only (5 sets of 5 reps, 90-95% 1-RM)] of bilateral knee extensions, whereas
the second bout consisted of a HV routine [upper-body (4 sets of 10 reps, 80-85%
1-RM) of bench press, seated row, and overhead shoulder press as well as lowerbody with bilateral knee extensions (5 sets of 5 reps, 90-95% 1-RM)]. Exercise
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
sessions were held one week apart in a randomized cross-over design. Serum free
and total TEST were measured immediately prior to and after exercise, and at .5 hr,
1 hr, 2 hr, 3 hr and 24 hr after exercise. Muscle biopsies were performed immediately
prior and after, 3 hr, and 24 hr after exercise. Separate (2 x 4) & (2 x 7) [Session x
TEST] ANOVA with repeated measures were performed with significant betweengroup differences determined by Tukey’s post Hoc TEST. RESULTS: No significant
main effects for time or group (p > .05) were observed for total and free TEST
indicating no changes in response to resistance exercise or between LV and HV.
However, a trend was observed (p=0.066) for an increase in free TEST with HV. In
addition, no significant main effects for time or group (p > .05) were observed for
skeletal muscle AR, myostatin, and MGF mRNA expression. CONCLUSIONS: Even
though previous research has shown serum TEST to be greater for HV resistance
exercise, these studies typically used untrained participants. The results presented
herein are contradictory, perhaps due to using resistance-trained participants, and
suggest that resistance exercise volume does not affect serum TEST which may
have a subsequent effect of the skeletal muscle expression of the AR, myostatin,
and MGF genes. PRACTICAL APPLICATIONS: Acute HV (upper and lower body
resistance exercise) in resistance-trained individuals may not result in the greater
TEST response typically seen with untrained individuals. This suggests that
training may involve other biochemical and molecular signaling mechanisms
which regulate muscle protein synthesis and contributes to increases in muscle
hypertrophy and strength.
Poster: 5
COMBAT-INDUCED POST-TRAUMATIC STRESS DISORDER RESULTS IN
BLUNTED ACUTE ENDOCRINE RESPONSES TO HEAVY RESISTANCE
EXERCISE A CASE STUDY
D. R. Wilson1, A. C. Fry1, M. J. Andre1, Z. A. Graham1, P. R. Dietz1, M. T. Lane1
1
The University of Kansas, Human Performance Laboratory, Lawrence, KS
*Award Eligible - Outstanding Master’s Student Poster Presentation
Individuals clinically diagnosed with post-traumatic stress disorder (PTSD)
reportedly exhibit a blunted endocrine response to stress due to “adrenal fatigue”
and disruption of central regulatory mechanisms. PURPOSE: The purpose of this
project was to determine the acute hormonal responses to a heavy resistance
exercise session for a male individual clinically diagnosed with PTSD. METHODS: A
combat-experienced U.S. Army Special Operations veteran previously diagnosed
with PTSD served as the case study subject (age = 29 yrs, Hgt = 1.80 m, BW = 111.1
kg, 1 RM squat = 130 kg, 1 RM bench press = 109 kg). Three healthy resistancetrained men served as comparison subjects (X±SD; age = 24.7±3.8 yrs, Hgt =
1.79±0.03 m, BW = 96.5±8.4 kg, 1 RM squat = 197.7±6.4 kg, 1 RM bench press =
140.3±15.0 kg). Each subject performed two test sessions in random-order, one a
control session where no exercise was performed, and one a free weight resistance
exercise session. Resistance exercise consisted of 3 x 10 at 70% 1 RM loads for
the parallel squat and the bench press exercises. Inter-set rest intervals were 1
min, with 2 min between exercises. Serum samples collected from a superficial
antecubital vein 15 min pre exercise (Pre) and 5 min post exercise (Post) were
analyzed for total testosterone, cortisol, and immunoreactive growth hormone
(IR GH; 22 kDa). Lactate (HLa) was sampled via finger-stick at the same times.
Serum samples were collected at identical times during the control session. All
testing was performed between 1630-1900 hrs, with times held constant for each
subject to minimize diurnal variations. ELISAs were used to determine circulating
concentrations for each hormone. Due to the small sample size, only differences
greater than 2 SD are reported (* >2 SD from corresponding PTSD value; ♦ >2 SD
from corresponding Pre value). RESULTS: HLa increased 12.7±0.7 mmol.L-1 for the
healthy subjects, and increased 9.7 mmol.L-1 for the subject with PTSD during the
resistance exercise session. The subject with PTSD exhibited blunted hormonal
concentrations at both Pre and Post exercise times. CONCLUSIONS: The anabolic/
catabolic hormonal profile for the subject with PTSD was considerably different
than what is observed for healthy subjects. These preliminary data support
disruption of central regulatory mechanisms and/or “fatigue” of peripheral
endocrine tissues in the presence of PTSD. Since a commonly prescribed therapy
for PTSD is exercise, this blunted hormonal profile could impact the expected
chronic adaptations. PRACTICAL APPLICATIONS: Individuals with PTSD may have
compromised adaptations to exercise due to the lower hormonal concentrations.
Additional study is required to determine if the findings for this case study are
consistent across the entire population diagnosed with PTSD, and if training
regimens need to be appropriately modified.
Poster: 6
THE ACUTE EFFECTS OF A PERFORMANCE MOUTHPIECE ON WHOLE BODY
REACTION TIME TO BALANCE PERTURBATIONS
C. Allen1, J. Lundahl2, H. Chander2, C. Zachary2, N. Dabbs2, J. C. Garner2
1
The University of Mississippi, 2University of Mississippi
*Award Eligible - Outstanding Doctoral Student Poster Presentation
INTRODUCTION: Temporomandibular joint position has been shown to have
a relationship with dynamic balance maintenance which can be uantified with
whole body reaction times through a manipulation of center of pressure. Previous
research investigating performance mouthpiece influence on reaction time is
focused primarily on voluntary reactions to stimuli. PURPOSE: The purpose
of this study was to investigate the acute effect of a commercially available,
performance mouthpiece on involuntary, whole body response time to balance
perturbations. METHODS: 21 recreationally trained males (age 21.5 ± 1.3 yrs; height
177.5 ± 7.9 cm; mass 87.1 ± 10.8 kg) completed the study. The first of three lab
visits included obtaining informed consent, familiarization with protocols, and
providing the mouthpiece and fitting instructions. The remaining two visits were
the experimental protocols, and were separated by exactly one week. The order of
completion for the mouthpiece (MP) and no mouthpiece (NoMP) conditions was
randomized for all participants. Each condition involved a warm-up consisting of
five minutes of cycling followed by supervised calisthenics. The warm up was
followed by administration of the motor control test (MCT) on the Neurocom
Equitest (NeuroCom, Inc., Clackams, OR). Participants in this investigation were
given no instructions to clench the jaw, only to perform as normal as possible.
Medium and large translations in the forward and backward directions were
analyzed by paired-sample t-tests, comparing differences between the MP and
NoMP conditions for latency of response to each perturbation. RESULTS: There was
no difference (p > 0.05) in reaction time between conditions for any perturbation
size or direction. CONCLUSIONS: The results of the current study indicate the use
of the mouthpiece has no influence on reactive automatic postural responses to
external balance disturbances. Further, use of the mouthpiece did not improve
coordination patterns in the whole body reactive response suggesting no influence
on involuntary whole body reactive motions. PRACTICAL APPLICATIONS: Although no advantage was illustrated in the study, no disadvantages were found
with regard to the specific test. Further research is warranted on the volitional
response to balance perturbations. ACKNOWLEDGEMENT: Funding for this
research was provided by the University of Mississippi Graduate Student Council.
Poster: 7
PACING STRATEGIES IN ELITE WOMENS FIELD HOCKEY
A. White1, N. MacFarlane1
1
University of Glasgow
PURPOSE: It has been previously shown that the intensity of team sport
competition decreases from the first to second half. However, field hockey rules
allow unlimited substitutions that allow players frequent rest periods during the
game. Therefore, we hypothesise that elite field hockey players can maintain
constant intensity levels throughout a game. METHODS: 15 female field hockey
players (mean±SD; age 25±3yrs; body mass 64.0±5.8 kg; maximal oxygen
consumption 52.9±4.5 ml.kg-1.min-1) were studied (giving forty player analyses
over five games). Physical activity was recorded using a 5-Hz global positioning
system. Full game analysis procedures were used to report data. RESULTS: Table 1
shows that average duration of 1st half was significantly less than 2nd half (36mins
[36 to 37mins] versus 38mins [37 to 39mins]; Mean [95%CI] p < 0.001). Markers
of intensity – distance covered, meterage, player load, efforts over 14km.hr-1, 18km.
hr-1 and 21km.hr-1 and maximum velocity were all similar (p > 0.05). CONCLUSION:
Unlike most other popular team sports, field hockey allows unlimited in-play
substitutions. This can mean players entering and leaving the game two or three
times in one half and allows for more rest time. The results from this study show
that intensity, as shown by selected markers, is maintained throughout the game.
This demonstrates that pacing strategies influence the intensity of game play in
elite level field hockey. PRACTICAL APPLICATION: This study demonstrates that
the intensity of game play is influenced by pacing strategies and as a consequence
the use of such strategies must be considered when planning conditioning
sessions for athletes in sports with rolling substitutions.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 8
MUSCLE ACTIVITY DURING PUSH-UP VARITIONS OF DIFFERING STABILITY
M. Breaux1, D. Bellar2, L. Judge3
University of Louisiana at Lafayette, Lafayette, La,
University of Louisiana at Lafayette, 3Ball State University, Muncie, IN
1
2
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Electromyography (EMG) measures the electrical activity of muscles. Using an
EMG, the muscles being used during push up variations were observed. PURPOSE:
In this study the activity of the pectoralis major and tricep brachii muscles during a
push-up done three different ways was monitored. The first was a standard pushup performed on the floor. The second was with the hands placed in straps that
were suspended from above and the feet placed on a stable platform, and the third
was with the hands and feet suspended in straps. METHODS: For this investigation,
the participants were seven college-aged males (BF:12.5± 2.5%) trained in the
technique of a push-up. The pectoralis major and the triceps brachii (lateral head)
muscles were monitored using EMG. The data was recorded and amplified, low
pass filtered and then iEMG signals over one concentric representative phase were
quantified. RESULTS: Data were analyzed via repeat measures Anova. The results
of the analysis from the iEMG of the Tricep by treatment were significant (F=4.12,
ηp2=0.407, p=0.043). The iEMG signal was the highest from the fully suspended
position followed by the hands only suspension with the lowest signals from the
standard push-up. These results were similar to those from the pectoralis major
(F=22.96, ηp2=0.793, p≤0.001) with the highest coming from the fully suspended
push-up. CONCLUSION: The fully suspended position resulted in the highest
iEMG signals, followed by the hands only suspension and then the standard
push-up. PRACTICAL APPLICATION: It is important to strength and conditioning
professionals to understand that the triceps and the pectoralis muscles seem to
be more active the more unstable the push-up gets, so strength coaches should
consider adding instability into similar movements to enhance muscle activity.
ACKNOWLEDGEMENTS: The authors would like to acknowlege the contributions
of TruFit LLC to the current project. Poster: 9
EFFECTS OF BLOOD FLOW RESTRICTION EXERCISE DURING ISOMETRIC
CONTRACTIONS ON NEUROMUSCULAR RECRUITMENT PATTERNS
T. Cayot1, A. Shaw1, C. Silette1, E. Garmyn1, B. Scheuermann1
1
University of Toledo
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Muscular hypertrophy has been demonstrated using blood flow restriction (BFR)
exercise at resistance intensities of 20%-40% of an individual’s maximal voluntary
contraction (MVC), similar to the results observed for resistance training at a much
higher percent of MVC. Current literature indicates that BFR exercise elicits a
greater neuromuscular recruitment compared to free flow (FF) exercise at similar
resistance intensities for dynamic exercise; however, the effects of BFR exercise
on isometric muscle contraction has not been previously examined. PURPOSE: To investigate the effect of BFR exercise on neuromuscular recruitment patterns
using surface electromyography (EMG) during various BFR conditions. METHODS:
Healthy, recreationally active, college-aged, male subjects (n=4; age 26±3.2
years; weight 88.5±12 kilograms) performed four repetitions of an isometric
knee extension exercise at 90° of knee flexion for each resistance intensity (20%
MVC, 40% MVC, 60% MVC, 80% MVC). Subjects performed the exercise during
three BFR conditions including control (CON), immediate occlusion (IO) and preocclusion (PO). Each participant performed three maximal voluntary isometric
contractions (100% MVC) at 90° of knee flexion for each BFR condition. The
external occlusion pressure (1.3 x SBP) remained constant throughout each of
the five sessions and was applied to the subject’s upper thigh on his dominant
leg using a pressure cuff (Hokanson, SC5, 6.5 cm). The external occlusion
pressure was applied immediately prior to the onset of exercise (IO), for five
minutes prior to the onset of exercise (PO), or not applied during exercise (CON).
Neuromuscular recruitment patterns of the vastus lateralis and vastus medialis
were measured via surface EMG techniques (sampling rate = 2,000 Hz; band-pass
filter of 10-500 Hz). The EMG signal for each isometric contraction was rectified
and the root mean square (RMS) for each muscle group was then calculated. The
RMS data was normalized as a percentage of an isometric MVC during CON BFR
conditions. Maximal force and the actual force generated at each target MVC
was measured using a force transducer connected to the subject’s ankle using a
cable. RESULTS: One-way ANOVA was used to analyze any potential difference
in neuromuscular recruitment patterns (RMS) between BFR conditions for each
of the target resistance intensities. Statistical significance was set at a priori of
p<0.05. No significant difference (p>0.05) in neuromuscular recruitment patterns
were observed between BFR conditions at any of the target resistance intensities.
CONCLUSION: The effects of BFR exercise are specific to the type of contraction
since the neuromuscular recruitment pattern during BFR exercise appears to be
different between isometric and isotonic exercise. The results of previous studies
suggest that isotonic exercise is associated with an increase in neuromuscular
recruitment with BFR exercise however, an increase in RMS was not observed
during isometric exercise with BFR. PRACTICAL APPLICATIONS: If using BFR
exercise to promote an increase in neuromuscular recruitment, it would be
suggested to perform isotonic BFR exercise compared to isometric BFR exercise.
Poster: 10
THE RELATIONSHIP BETWEEN AROUSAL LEVELS AND GOLF PUTTING DURING
THREE DIFFERENT CONDITIONS: A PILOT STUDY
A. Elumalai1, D. Szymanski1, J. Parks1
1
Louisiana Tech University
*Award Eligible - Outstanding Master’s Student Poster Presentation
Arousal is a major aspect of many learning theories and is closely related to
concepts such as anxiety, attention, agitation, stress, and motivation. Arousal
level is one of the most powerful factors to affect the performance of the players. PURPOSE: To determine if there is any a connection between arousal levels and
putting in different settings. Another purpose of this study was to define the way
for future research in determining the relationship. METHODS: 6 NCAA Division 1
golfers (handicap < 3) volunteered for this study. All subjects signed an informed
consent according to the university’s Institutional Review Board. Subjects’
characteristics were age 20.2 ± 1.5 yr and played for the same division under the
same coach and practice conditions. The participants were instructed to wear the
Zephyr device while putting. Zephyr HxM BT heart rate monitor It detects the
time between two of the distinctive, large, upward “R” spikes during the QRS
complex of heart rate, and the Mind Meter tracks the arousal levels by recording
the subtle changes in the R-R interval between each heartbeat. In the first session,
on a flat putting green surface the participants were randomly assigned 5 putts
each from 3 distances -3, 6, and 9 feet from the hole. The data from the Mind
Meter was recorded before, during, and after each putt. In the second session, the
participants were assigned 5 putts each from 3 distances located from 5 different
positions - uphill lie, downhill lie, side hill lie from right to left, side hill lie from left
to right, and flat surface outside on the practice greens at Squire Creek. In the
third session, the arousal levels were raised by changing the emotional factor of
the golfers by exposing them to a competition for a prize, at Squire Creek. The
accuracy of the putts was monitored by measuring the number of accurate putts
and distance between the ball and hole in case of a missed putt. RESULTS: The
average of arousal levels during the makes and misses was used to determine
the relationship between different settings and arousal levels. There was little or
no correlation among the different settings and optimum arousal levels varied
in the players. CONCLUSIONS: The results suggested that each player had an
individualized optimum arousal level during different settings whether they
made or missed the hole. The findings of this pilot study indicated that definitive
results regarding the optimum arousal levels and different setting required a
larger sample size and more data in each setting. For the best performance the
athletes may need individualized zones of optimum arousal levels. PRACTICAL
APPLICATION: Players can improve the success of their game during competitions
by using Zephyr HxM BT heart rate monitor to determine the arousal levels when
they putt affectively during a controlled setting. Further research is needed to
determine the relationship of arousal levels and putting in athletes of different
categories.
Poster: 11
PRELIMINARY INVESTIGATION INTO THE SUITABILITY OF AN
ALTERNATIVE FORM OF COUNTERMOVEMENT JUMP TEST ANALYSIS
FOR ATHLETE FATIGUE MONITORING
R. Gathercole1, B. Sporer2, T. Stellingwerff2, G. Sleivert2
University of Victoria, BC, Canada/CSI-Pacific, Victoria, BC, Canada/Sport
Innovation Centre, Victoria, BC, Canada, 2University of Victoria, BC, Canada/
CSI-Pacific, Victoria, BC, Canada
1
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: The countermovement jump (CMJ) test is an athlete monitoring
tool used to examine neuromuscular (NM) function and fatigue state. There is
uncertainty though as to which components of CMJ performance are most
sensitive to post-exercise fatigue. Here we assess the suitability of the CMJ test
for the detection of post-exercise fatigue, examining an alternative form of CMJ
analysis based on jump traces (aCMJ) compared to more typical CMJ-derived
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
measures (tCMJ). METHODS: 7 elite snowboard athletes (4M, 3F) performed 6
CMJ tests prior to and 30 min following repeated stair climbs to fatigue. CMJ
was evaluated using the Ballistic Measurement System (BMS; Fitness Technology,
Australia). 20 aCMJ variables based on time, work and single-points during
the jump were analysed using custom-designed software, with raw jump data
extracted from the BMS. aCMJ variables (6 reported): Time: eccentric (EccT),
concentric (ConT), total jump duration (TotT); Work: area under the force-velocity
trace (FV-AUC), total area under the PT curve (PT-AUC); Single-point: force at
zero velocity (F@0V). tCMJ variables: jump height (JH), peak power (PP), peak
velocity (PV), peak and mean force (PF, MF). ‘Outlier’ jumps were removed using
standardised procedures. Coefficients of variation (CV) were calculated for each
pre and post-variable to examine whether variability of each variable would
permit detection of fatigue-induced changes. RESULTS: Significant differences
pre- to post-exercise (p-value) were observed for aCMJ variables for time (EccT:
+0.07s, 0.042; TotT: +0.08s, 0.048), work (FV-AUC: -523N.ms-1, 0.047) and
single point (F@0V: -158N, 0.031), while tCMJ variables PF (-120N, 0.032) and
MF (-40N, 0.007) were also significant. All other aCMJ and tCMJ variables were
not significantly different. CONCLUSIONS: Compared to tCMJ, the use of aCMJ
variables appear better suited to the detection of NM fatigue. The aCMJ variables
relate to how the CMJ is performed rather than tCMJ, which focuses on the CMJ
output. Rather than a decreased capacity to produce a jump output (i.e. jump
height, peak power), these findings suggest that fatigue expresses itself as an
altered CMJ movement pattern. Fatigue state may therefore be better identified
through examination of how the CMJ is performed (i.e. aCMJ). The lack of change
in PT-AUC suggests that similar work was performed during the CMJ. However
the speed and timing of this work appeared decreased and delayed significantly.
PRACTICAL APPLICATIONS: These results indicate that although fatigue may not
ultimately influence end NM output, it appears to alter NM strategy, decreasing the
speed-efficiency of movement. Given the importance of speed and timing in many
sports, this has a number of important implications. These results suggest that a
practical test such as the CMJ can be used to examine changes in NM movement
strategy but that tCMJ analysis may not be as suitable for the monitoring of
fatigue state as aCMJ variables.
Poster: 12
VASTUS MEDIALIS OBLIQUE AND VASTUS LATERALIS ACTIVATION DURING
CLOSED KINETIC CHAIN EXERCISES
B. Gatzke1, M. Fauth2, W. Ebben3
1
UW-LaCrosse, 2Ohio State University Medical Center, 3UW-Parkside
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
PURPOSE: The quality of the activation of the vastus medialis oblique (VM), as
well as it’s ratio of activation with the vastus lateralis (VL) have been proposed
to be important in the reduction of patellofemoral pain syndrome and to improve
patellar tracking. However, research has yet to quantify how resistance training
exercises activate these muscles in order to compare the activation of the VM
or the VM to VL ratio (VM:VL). The purpose of this study was to compare VM
activation and VM:VL using surface electromyography during four closed kinetic
chain resistance training exercises. METHODS: Sixteen women (mean±SD;
age=21.19±2.17 years; height=169.39±7.54 cm; body mass=66.08±9.91 kg) who
participated in either NCAA Division I, club, or intramural sports, as well as lower
body resistance training volunteered and provided informed consent.Independent
variables included the type of resistance training exercise and the muscle action
phase of the exercise (eccentric or concentric) for the vastus medialis oblique
(VM) and the VM:VL. Test exercises included the squat, deadlift, step up and lunge,
each performed with a 5 repetition maximum load. Dependent variables included
the root mean square (RMS) EMG expressed as a percentage of the MVIC.Data
were evaluated with a repeated measures ANOVA to test main effects of RMS EMG
for the VM and VM:VL for each exercise assessed. Bonferroni adjusted post hoc
analyses were used to assess the specific differences in muscle activation between
each exercise. RESULTS: Significant main effects representing differences in VM
RMS EMG between the resistance training exercise were found for the eccentric
phase (p=0.003) and concentric phase (p=0.014). The squat resulted in 36.9%
greater eccentric VM activation than the deadlift and step up, while the lunge
produced 48.0% more activation than the deadlift. The lunge resulted in 22.1%
greater concentric VM activation than the squat and 38.5% greater activation than
the deadlift. The step up produced 24.3% more concentric VM activation than
the deadlift. No significant differences were found for VM:VL for the eccentric
(p=0.61) or concentric (p=0.26) phase. CONCLUSION: Exercises with the greatest
VM activation may help reduce patellofemoral pain and improve patellar tracking.
However, no differences in VM:VL were found in the exercises assessed. PRACTICAL
APPLICATION: Training with exercises such as the squat and lunge offer more VM
RMS EMG activation during the eccentric phase, while the lunge and step up offer
the greatest VM RMS EMG activation during the concentric phase, compared to
the other exercises assessed.
Poster: 13
EFFECTS OF ECCENTRIC-INDUCED MUSCLE DAMAGE ON THE TIME COURSES
OF RECOVERY FOR PEAK TORQUE AND RATES OF TORQUE DEVELOPMENT
N. D. Jenkins1, D. A. Traylor1, T. J. Housh1, H. C. Bergstrom1, K. C. Cochrane1,
R. W. Lewis, Jr1, R. J. Schmidt1, G. O. Johnson1, J. T. Cramer1
1
University of Nebraska-Lincoln
*Award Eligible - Outstanding Master’s Student Poster Presentation
INTRODUCTION: Molina and Denadai (Clin Physiol Funct Imaging, 32: 179-184,
2012) recently reported differences in the time courses of recovery between
peak torque (PT) and peak rate of torque development (pRTD) after eccentricinduced muscle damage in the leg extensors. Less is known about rate of torque
development (RTD) recovery in commonly measured time intervals of 10, 50,
100, and 200 ms or whether differences exist in the forearm flexors. PURPOSE:
Examine the time courses of recovery for PT and RTD at peak, 10, 50, 100, and 200
ms for up to 72 h after eccentric-induced muscle damage in the forearm flexors.
METHODS: Eighteen men (mean±SD age = 22±3 yrs; body mass = 81±16 kg;
height = 183±6 cm) completed six sets of ten maximal isokinetic eccentric muscle
actions at 30°·s-1 on an isokinetic dynamometer. Maximal voluntary isometric
contractions were measured before (PRE), immediately after (POST), and 24, 48,
and 72 h after the eccentric exercise. Serum concentrations of creatine kinase
(CK) and lactate dehydrogenase (LDH) were measured at the same time points.
PT, pRTD, and RTD at 0-10 (RTD10), 0-50 (RTD50), 0-100 (RTD100), and 0-200
ms (RTD200) from the onset of torque were calculated from the first derivative of
the torque signal. PT and RTD variables were normalized as a percentage of PRE.
RESULTS: MeanCK (±SD) increased (p<0.05) from 138 (±175) to 6,457 (±12,769)
IU·L-1 and LDH increased (p<0.05) from 116 (±29) to 199 (±196) IU·L-1 from PRE
to 72 h. PT and all RTD variables decreased at POST (p<0.05). PT and RTD200
remained lower than PRE through 72 h (p<0.05). pRTD remained lower than PRE
through 48 h (p<0.05), but was not different from PRE at 72 h (p>0.05). RTD10
and RTD100 were lower than PRE through 24 h, but were not different from
PRE at 48 and 72 h (p>0.05). RTD50 decreased at POST, but was not different
from PRE at 24 h (p>0.05). Normalized PT was greater than pRTD, RTD10, and
RTD50 at POST (p<0.05); however, normalized PT was less than (p<0.05), pRTD,
RTD10, and RTD50 at 72 h. In addition, RTD50 was greater than RTD100 (p<0.05)
and RTD100 was greater than RTD200 (p=0.04) at 48 h; RTD10 was greater
than RTD200 (p<0.01) at 72 h; and RTD50 was greater than RTD100 (p=0.02),
RTD200 (p=0.02), and PT (p=0.02) at 72 h. CONCLUSIONS: Eccentric-induced
muscle damage caused greater relative decreases in pRTD, RTD10, and RTD50
than PT at POST, while pRTD (84%PRE), RTD10 (97%PRE), and RTD50 (117%PRE)
all recovered to a greater extent than PT (72%PRE) at 72 h. RTD50 recovered the
quickest by 24 h, whereas RTD200 responded similarly to PT and never returned
to PRE levels during the 72 h recovery. PRACTICAL APPLICATIONS: For sports
such as kicking, sprinting, or jumping that are associated with explosive rates of
force development, performance may suffer greater decrements initially from
exercise-induced muscle damage, but may subsequently recover quicker and to a
greater extent than maximal strength within 72 h. Poster: 14
GENDER ANALYSIS OF HAMSTRING AND QUADRICEPS ACTIVATION RATIOS
DURING BILATERAL AND UNILATERAL JUMP LANDINGS
K. Laskowski1, J. Endisch1, L. Garceau2, W. Ebben1
1
UW-Parkside, 2Marquette University
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
PURPOSE: Low hamstrings to quadriceps activation ratios (H:Q) may increase
the liklihood of knee injury, including the rupture of the anterior cruciate
ligament (ACL). Women experience 2 to 8 times more ACL injuries than men. Thus, gender differences exist. However the research is mixed with respect to
gender differences in knee joint muscle activation during jump landings, and its
potential role in these types of injuries. Therefore, this study evaluated gender
differences in H:Q of college athletes, during jump landings. METHODS: Subjects
include 12 women (age = 19.8 ± 1.4 years; height = 175.49 ± 5.9 cm; weight =
73.21 ± 10.37 kg) and 8 men (age = 20.8 ± 0.9 years; height = 189.71 ± 5.80 cm;
weight = 87.10 ± 7.70 kg). Subjects were evaluated using electromyography (EMG)
to quantify rectus femoris, vastus lateralis, vastus medialis, lateral hamstring, and
medial hamstring activation during bilateral countermovement jumps (BCMJ)
and unilateral countermovement jumps (UCMJ). Data were normalized to a
maximum voluntary isometric contraction (MVIC) and expressed as an aggregate
of hamstring and quadriceps muscles, forming the H:Q. Data were analyzed
using a one-way ANOVA to examine gender differences in EMG during the jump
landings. RESULTS: During UCMJ, men produced a H:Q ratio of .59 ± .31 whereas
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
women had a H:Q ratio of .35 ± .18, which was significantly different (P = 0.039).
During the BCMJ jump landing, men demonstrated H:Q of .66 ± .23 whereas the
ratio of women was .46 ± .21 which was trending toward a significance difference
(P= 0.075). CONCLUSION: Women demonstrate lower mean H:Q ratio during
BCMJ, and significantly lower H:Q during UCMJ, representing less hamstring and
more quadriceps activation during jump landings, compared to men. Thus, gender
differences in muscle activation strategies are present and the magnitude of the
differences is more pronounced in the single leg, and thus more intense, jump
landing condition. PRACTICAL APPLICATION: Strength and conditioning coaches
should train women athletes with the goal of increasing hamstring strength, and
thus improving their H:Q. ACKNOWLEDGEMENTS: The authors wish to thank the
research participants.
Poster: 15
ELECTROMYOGRAPHIC AMPLITUDE VERSUS AVERAGE CONCENTRIC AND
ECCENTRIC SQUAT FORCE RELATIONSHIPS
M. Luera1, M. S. Stock1
1
Texas Tech University
*Award Eligible - Outstanding Master’s Student Poster Presentation
The relationship between signal amplitude and force is one of the most frequently
studied s in electromyography (EMG) research. This is largely due to the desire
among researchers and clinicians to study the relative effort of individual muscles
during a contraction. However, all of the previous authors that have examined
this have done so for single-joint strength tests. PURPOSE: This study examined
the linearity of the EMG amplitude versus concentric and eccentric squat force
relationships for the vastus lateralis (VL). METHODS: Fourteen resistance-trained
men (mean ± SD age 22 ± 2 years) participated in this study. Forty-eight hours
following a familiarization session, the subjects performed submaximal concentric
and eccentric isovelocity squats in 10% increments (i.e., 10%, 20%, etc.). The
durations of both the concentric and eccentric muscle actions were set to four
seconds, and an electrogoniometer placed over the lateral aspect of the right
knee ensured that all squats were performed through an 80° range of motion.
Bipolar surface EMG signals from the VL were collected for all trials. The average
force value (N) and the amplitude (µV RMS) of the EMG signal were determined
for the middle portions of the concentric and eccentric muscle actions for each
subject. Linear regression analyses were used on an individual subject basis to
examine the coefficients of determination (r²), linear slope coefficients (µV · N-1),
and significance levels for these relationships. A paired samples t-test was used
to compare the mean linear slope coefficients for concentric versus eccentric
testing. A two-way (muscle action [concentric versus eccentric] x force [10-90%])
repeated measures analysis of variance (ANOVA) was performed on the absolute
EMG amplitude values. RESULTS: There was no mean difference between the
concentric and eccentric muscle actions for the linear slope coefficients of the
EMG amplitude versus force relationship (p = 0.055). The results for the two-way
repeated measures ANOVA indicated that there was no interaction, but there were
main effects for both muscle action (concentric > eccentric) and force (10% <
20-90%, 20% < 30-90%, 30% < 40-90%, 40% < 60-90%, 50 < 70-90%, 60% <
80-90%, 70% < 80-90%). DISCUSSION: The coefficients of determination for this
investigation showed moderate-to-high degrees of linearity, with similar findings
for concentric and eccentric muscle actions. Our results are comparable to previous
studies examining the linearity of the EMG amplitude versus torque relationship
during unilateral isokinetic muscle actions. PRACTICAL APPLICATIONS: During
squats performed with a standardized range of motion and movement pattern,
EMG amplitude for the VL increases with force in a fairly linear fashion. Future
investigators might consider examining the electrical activity of antagonistic
biarticular muscles of the thigh during isovelocity squats.
Poster: 16
THE EFFECTS OF DIFFERENT WARM-UP MODALITITES ON
GLUTE MEDIUS ACTIVATION
R. S. Nadell1, J. Nicoll1, D. L. Hatfield1
1
University of Rhode Island
*Award Eligible - Outstanding Master’s Student Poster Presentation
PURPOSE: Muscle imbalance assessment and treatment practices are becoming
more commonplace in the field of strength and conditioning. For instance,
exercises such as monster walks are being prescribed as a warm-up exercise
with the specific aim of activating and/or strengthening the gluteus medius (GM)
muscle. There is evidence to suggest that an individual with either a weak GM or
one that is recruited asynchronously has an increased risk of injury. However, this
relationship has not been established in a resistance trained athletic population.
Further, there is no evidence that commonly used glute activation (GA) exercises
will acutely increase synchronized recruitment. Therefore, the primary purpose
of this research is to examine the effects of different warm-up modalities on
GA. METHODS: Nine men (age: 20.7 ±2.1 yrs; body mass: 86.0±12.97 kg; height:
177.5±13.1cm; body fat percent: 12.66 ± 4.0) and thirteen women (age: 20.2 ±1.4
yrs; body mass: 73.73±15.6 kg; height: 165.1±12.8cm; body fat percent: 22 ± 4.2)
volunteered to participate in this randomized, cross-over study. Each participant
was tested for GA using manual field tests (Cook Hip Lift and a Side-lying
Abduction Test) and EMG, prior to and after performing one of two warm-up
exercise conditions; a standard dynamic warm-up (DW) or common GA exercises.
Statistical significance was set at p≤0.05 RESULTS: As expected, men exhibited
significantly greater mean and max GM EMG activity when compared to women at
all time points for all conditions. There were no significant differences in mean and
max GM EMG activity between the GA exercise and the DW condition. There were
also no main effects of time (pre and post condition). CONCLUSION: The findings
suggest that a non-injured, athletic population may be able to properly activate
the GM without any additional stimulation. The resistance training experience of
this varied greatly but all had at least 6 months prior training experience. Future
studies should examine if there is a relationship between resistance training and
GA, but it is possible that resistance trained athletes can adequately strengthen
the GM through the course of normal training and subsequently would have no
problems recruiting the GM. PRACTICAL APPLICATIONS: Strength & conditioning
professionals have limited time with athletes. When coaching a resistance trained
athletic population, the results of this study suggest strength & conditioning
professionals should reallocate time spent on GA assessment and treatment to
protocols that will enhance performance.
Poster: 17
RELIABILITY AND VALIDITY OF THE MANUAL SIDE-LYING HIP
ABDUCTION GLUTEUS MEDIUS ACTIVATION ASSESSMENT IN THE
STRENGTH AND CONDITIONING FIELD
J. Nicoll1, R. S. Nadell1, D. L. Hatfield1
1
University of Rhode Island
*Award Eligible - Outstanding Master’s Student Poster Presentation
INTRODUCTION: The gluteus medius (GM) is an important hip stabilizer muscle.
Non-activation of the GM is related to increased risk of injury of lower limbs
and reduced running speed and efficiency. Many strength and conditioning
coaches (SCC) incorporate glute activation (GA) assessment and exercise into
practice to activate and strengthen the GM. One widely used field test of GA is
the manual side-lying hip abduction test (MLHA.) However, previous research
suggests inter-rater reliability of this assessment test is low. Despite this poor
reliability and absence of substantial research supporting MLHA as a valid test of
GA, many SCCs continue to utilize this test as an assessment of GA. PURPOSE:
Thus, the purpose of this study was to determine SCC inter-rater reliability and
validity using MLHA as a GA assessment in athletes. METHODS: Nine men (age:
20.77±2.10 yrs; body mass: 86.0±12.97 kg; height: 177.5±13.1cm; body fat percent:
12.66 ± 4.0) and thirteen women (age: 20.23±1.48 yrs; body mass: 73.73±12.15
kg; height: 165.1±12.8cm; body fat percent: 22 ± 4.2) participated in the study.
All participants were resistance trained collegiate athletes. Electromyography
(EMG) electrodes were placed on the GM by the same investigator prior to every
trial. Prior to and after a warm-up protocol participants were assessed for GA
manually using the MLHA standard scoring protocol by one of two coaches.
Standard scoring ranges from grade 0-5, with 0 meaning poor or no GA and
5 meaning adequate GA. One week later the participants were tested by the
other coach. Intraclass correlation (ICC) was calculated to determine reliability
between the coaches’ MLHA scores and Pearson Correlations between the MLHA
scores and EMG activity were assessed to determine validity. RESULTS: There
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
were no significant correlations between MLHA scores and mean or maximum
EMG activity at any time point. Inter-rater reliability between the coaches MLHA
scores was low (Cronbach Alpha=0.201 and ICC=0.284.) Test-retest reliability
for the EMG was high (Cronbach Alpha=0.864 and ICC=0.809.) CONCLUSION:
The athletic population being evaluated were very well trained and did not have
any GA dysfunction. Although MLHA scores reported by the coaches indicated
GA in the participants, the coaches still reported significantly different MLHA
scores. Previous studies have reported a similar lack of reliability in a physical
therapy setting with a sedentary population. Electromyography activity has been
reported to be a valid and reliable measurement of GA and reliability of EMG
in the current study was high. However, it is expensive and impractical tool for
SCCs to use, hence the need for reliable field assessments. The results of this
study indicate that MLHA is neither a reliable nor valid field assessment tool in
resistance-trained athletic population. PRACTICAL APPLICATION: Currently, any
training SCCs get for common field assessments is through workshops and/
or self-learning. Professionals in the field should be cautious when suggesting
and/or implementing new assessment techniques; taking into account reliability
and validity of the assessment and the population they will be performing the
assessment on.
Poster: 18
TIBIAL ACCELERATION IN DISTANCE RUNNERS IN REDUCED
BODY WEIGHT CONDITIONS
B. J. Rickert1, M. F. Moran1, B. Greer1
1
Sacred Heart University
*Award Eligible - Outstanding Master’s Student Poster Presentation
Seventy-two percent of all athletic stress fractures are the result of running, with
nearly half occurring in the distal end of the tibia. PURPOSE: The purpose of
this study was to investigate the relationship between the level of body weight
(BW) in an unloader treadmill and tibial acceleration (TA). Research reports that
increased vertical ground reaction force during running is positively correlated to
peak TA. METHODS: Fifteen collegiate cross country runners (9M; 20.4 ± 2.4 yrs;
60.1 ± 12.6 kg) granted informed consent and participated in the present study.
Following a 10-minute familiarization run on an unloading differential air pressure
treadmill each subject started at 100% BW and ran at a consistent velocity for
three minutes during each of nine stages which progressively decreased at 5%
intervals until 60% BW for a total of 37 minutes. During the last 30 seconds
of each stage, TA and heart rate (HR) were measured. TA was assessed with a
skin-mounted uniaxial accelerometer attached to the lower third of the anterior
tibia and data were recorded via computer data collection system and processed
with custom-written data processing code. HR data was collected via a heart
rate monitor. A repeated measures analysis of variance with Bonferroni post-hoc
comparison was used to analyze the data. Significance level was set apriori at
p<0.05. RESULTS: There were no significant differences between TA from 100%
BW (10.59g) to any level of unloading (60%-95%). Mean peak tibial acceleration
initially increased with the levels of unloading (95%-75%) before dropping below
100% BW TA levels at 70%. Mean peak-to-peak TA was significantly less (p= 0.021)
at 60% BW (16.55g) as compared to 100% BW(18.56g). CONCLUSION: Tibial
accelerations are not directly related to level of BW on an AGTM. PRACTICAL
APPLICATIONS: Based on the present study, a runner rehabilitating from a tibial
stress fracture/reaction should begin rehabilitation at BW levels below 60% BW
to maintain stress levels below normal. By running at these reduced BW levels,
the runner better maintain aerobic fitness while still rehabilitating from a tibial
stress fracture as opposed to traditional rehabilitation protocol which is rest. Poster: 19
CONSISTENCY OF PANORAMIC ULTRASOUND IMAGING TO EXAMINE
MUSCLE SIZE AND QUALITY
J. G. Rosenberg1, E. D. Ryan1, E. J. Sobolewski1, B. J. Thompson2,
M. J. Scharville1, G. E. King1
1
The University of North Carolina at Chapel Hill, 2Oklahoma State University
*Award Eligible - Outstanding Master’s Student Poster Presentation
The popularity of ultrasound (US) devices to examine muscle architecture has
increased due to its ease of use and portability. New panoramic imaging capabilities
have allowed researchers to quantify both muscle size through cross-sectional
area (CSA) measurements and muscle quality using echo intensity (EI) analyses
of a single image. Although these techniques seem promising, the consistency
of these assessments warrants further evaluation. PURPOSE: The purpose of the
present study was to determine the test-retest reliability for CSA and EI assessed
from a single image using the panoramic US technique. METHODS: Sixteen
healthy, recreationally active males (mean ± SD age, 20.9 ± 2.5 years; height,
173.7 ± 6.9 cm; mass, 74.2 ± 9.7 kg) volunteered for this investigation. Participants
visited the laboratory on 2 separate occasions separated by 2 - 7 days at the same
time of day (± 2 hrs). During all measurements, participants were examined in the
prone position with their leg fully extended and right foot securely attached to a
vertical post at a 90° joint angle between the foot and leg. To ensure the probe
moved perpendicular to the skin and along the transverse plane during each
scan, a custom made probe support composed of high-density foam padding
was positioned perpendicular to the longitudinal axis of the leg. The probe
was then moved manually with slow and continuous movement from the most
medial aspect of the medial gastrocnemius (MG) to the beginning of the lateral
gastrocnemius. A generous amount of water-soluble transmission gel was applied
to the skin to reduce possible near field artifacts and enhance acoustic coupling.
Transverse measurements of the MG were obtained using a portable B-mode US
imaging device. All US imaging analyses were performed using Image-J software.
Test-retest reliability for CSA and EI were determined using Model 2,1 to determine
the intraclass correlation coefficients (ICC), standard error of measurement (SEM),
and minimum difference (MD) values per the recommendations of Weir (2005).
Systematic error was examined using separate one-way repeated measures
analyses of variance (ANOVAs). RESULTS: The reliability statistics for CSA and EI
are presented in this study. CONCLUSIONS: The ANOVAs indicated no systematic
error between days. Relative consistency was acceptable with ICC values of 0.914
and 0.720 for CSA and EI, respectively. Absolute consistency was also acceptable
with SEM values (expressed as a percentage of the mean) of 5.83 and 3.68% for
CSA and EI, respectively. Minimal changes to be considered real for CSA and EI
were 1.995 cm2 and 7.298 a.u., respectively. These findings demonstrate that the
panoramic US imaging technique may be a reliable technique for simultaneously
measuring muscle size and quality. PRACTICAL APPLICATIONS: Future studies
may use panoramic US imaging to examine the influence of aging, disease, and
training on muscle size and quality.
Poster: 20
TEST-RETEST RELIABILITY OF PEAK AND AVERAGE CONCENTRIC AND
ECCENTRIC ISOVELOCITY SQUAT FORCE
J. Shields1, M. S. Stock1, M. Luera1
1
Texas Tech University
*Award Eligible - Outstanding Master’s Student Poster Presentation
Strength and conditioning professionals are interested in knowing whether small
changes in force production are meaningful. A recent development in strength
testing technology allows subjects to perform multiple-joint exercises while
movement velocity is controlled. Termed “isovelocity” testing, the duration for
both the concentric and eccentric phases, as well as the range of motion, can be
pre-determined by the tester. PURPOSE: The primary purpose of this investigation
was to examine test-retest reliability statistics for peak and average force during
maximal concentric and eccentric isovelocity squats. The secondary purpose was
to assess whether analyzing data for solely the middle portion of the range of
motion improved the trial-to-trial consistency. METHODS: Seventeen resistancetrained men (mean ± SD age = 21 ± 2 years, body mass = 81.1 ± 8.1 kg) participated
in this study. The subjects visited the laboratory on two occasions separated by
48 hours. For each trial, the subjects performed three maximal concentric and
eccentric squats using a standardized range of motion, and the repetitions with
the highest force values were selected. The duration was set to four seconds for
both the concentric and eccentric phases. Data analyses included determining
the peak and average force values throughout the entire ranges of motion, as
well those excluding the one second acceleration and deceleration phases (i.e.,
the middle two seconds). Statistical analyses included the p-values for eight
separate paired-samples t-tests, 95% confidence intervals (CI) for each mean
difference, intraclass correlation coefficients (ICCs [models 2,1 and 3,1]), standard
errors of measurement (SEMs [calculated as the square root of the mean square
error]), and minimal differences (MDs) needed to be considered real between
the trials. RESULTS: There were no mean differences between the trials for the
eight variables examined in this study. The ICCs ranged from 0.676 to 0.848.
When expressed as a percentage of the mean value for both trials, each of the
variables showed SEMs of less than 11%. DISCUSSION: The results of the present
study demonstrated moderate-to-high test-retest reliability for the peak and
average force values obtained from maximal concentric and eccentric isovelocity
squats. The data for the concentric repetitions were more reliable than those for
the eccentric repetitions, and similar levels of consistency were shown when the
entire force curve was analyzed as opposed to only the middle of the range of
motion. PRACTICAL APPLICATIONS: It is in the best interest of practitioners to
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
compute test-retest reliability statistics before using a given measurement to
assess the effectiveness of an intervention. Our results showed that the peak and
average concentric and eccentric force values obtained during isovelocity squats
were generally reliable. These statistics would likely be improved with multiple
familiarization sessions.
Poster: 21
A COMPARISON OF THE ACUTE EFFECTS OF CONCENTRIC VERSUS ECCENTRIC
EXERCISE ON STRENGTH AND FORCE STEADINESS
X. Ye1, T. W. Beck2, J. M. DeFreitas2
1
The University of Oklahoma, 2University of Oklahoma
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Concentric (CON) and eccentric (ECC) muscle actions are involved in nearly all
sporting activities. Generally speaking, acute force loss following concentric
exercise is due to muscle fatigue, while that after eccentric exercise is caused
less by muscle fatigue, and more by muscle damage. In addition, the loss of
strength also affects the ability to control submaximal forces, which is often
referred to as force steadiness. PURPOSE: To compare the acute effects of two
different exercise interventions (CON and ECC) on strength and force steadiness.
METHODS: Fourteen resistance-trained males (age = 24 ± 4 yr; height = 179.5 ± 6.4
cm; body weight = 86.8 ± 10.8 kg) participated this research study and finished all
three visits. On Visit 1, the subjects established their baseline isometric maximum
voluntary contraction (MVC) of the dominant forearm flexors, practiced several
submaximal isometric contractions, and then were familiarized with both exercise
interventions (CON and ECC). During Visits 2 and 3, CON and ECC exercises
were randomly assigned to each subject. Before the exercise intervention,
subjects performed one MVC followed by three 10-second submaximal isometric
contractions at the strength level of 40% baseline MVC. Right after they finished
the pre-testing, subjects were told to perform 6 sets of 10 contractions (CON or
ECC) on an isokinetic dynamometer at a velocity of 60°/second. One minute of
rest was provided after each exercise set. Once the subjects finished the exercise,
post-testing was performed as the exactly same procedure and order as the
pre-testing, with the caveat that the submaximal isometric contractions were
performed at 40% of the baseline (as opposed to the current) MVC. The force
steadiness was calculated as the standard deviation of the force (force SD) being
generated during 10 seconds of the 40% baseline MVC contraction. Two separate
two-way (time [pre vs. post] × condition [CON vs. ECC]) repeated measures
analyses of variance (ANOVAs) were used to examine the changes in strength and
force steadiness due to the two exercise interventions. When appropriate, followup analyses included Bonferroni post hoc comparisons. RESULTS: The results
for strength showed that there was no significant time × condition interaction,
but there was a significant main effect for time, but not for condition. Average
strength decreased 24.86% following the CON exercise and 30.08% following the
ECC exercise. The results for force steadiness showed that there was a significant
time × condition interaction. Follow-up analyses showed significant decreases
in force steadiness following both exercise interventions, but the decrease after
the ECC intervention was greater than that following the CON intervention.
CONCLUSIONS: High intensity CON and ECC exercise caused similar strength
loss. However, force steadiness was impaired more after ECC exercise than CON
exercise. PRACTICAL APPLICATIONS: Concentric and eccentric exercise resulted in
similar acute strength losses. However, the finding that force steadiness decreased
more following the eccentric exercise, when compared to the concentric exercise,
suggested that performance during activities that rely heavily on force steadiness
(e.g., balance, postural stability, etc.) may be particularly reduced following
activities that have a high eccentric component.
Poster: 22
AGE-RELATED DIFFERENCES IN BODY WEIGHT, HEIGHT, BODY MASS INDEX,
AND UPPER BODY SKINFOLDS BETWEEN YOUNG WRESTLERS AND NONATHLETES.
K. C. Cochrane1, T. J. Housh1, H. C. Bergstrom1, D. A. Traylor1, R. W. Lewis, Jr1,
N. D. Jenkins1, D. J. Housh2, G. Johnson1, J. T. Cramer1, R. Schmidt1
1
University of Nebraska-Lincoln, 2University of Nebraska Medical Center
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Purpose: This study examined the age-related mean differences in body weight
(BW), height (HT), and indirect indicators of adiposity of 11 to 18-year-old male
wrestlers versus a national representative sample of non-athletes. Methods:
One hundred and sixteen male wrestlers (Mean age ± SD = 14.38 ± 2.24 yr; BW
= 55.24 ± 15.20 kg; HT = 162.05 ± 13.75 cm) were divided into eight independent
age groups (AG): (AG) 11 = 11.00 -11.99; (AG) 12 = 12.00 - 12.99; (AG) 13 = 13.00
-13.99; (AG) 14 = 14.00 - 14.99; (AG) 15 = 15.00 - 15.99; (AG) 16 =16.00 - 16.99;
(AG) 17 = 17.00 - 17.99; and (AG) 18 = 18.00 - 18.99 yr. Data from the National
Health and Nutrition Examination Survey (NHANES) 2003-2008 were used as
the non-athlete comparison samples. Five variables (BW, HT, body mass index
(BMI), subscapular skinfold (SF), and triceps SF) were assessed and independent
t-tests were used to compare the variables for each age group of the wrestlers
with the non-athletes. Results: There were no mean differences between the
wrestlers and non-athletes for any of the age groups for BW, HT, or BMI. The
wrestlers, however, had significantly (p < 0.05) smaller subscapular (AG 11, 12, 13,
14, and 18) and triceps (AG 12, 14, 17, and 18) SF values than the non-athletes. In
addition, for both samples, there were age-related increases in BW, HT, BMI, and
subscapular SF, and decreases in triceps SF. Discussion: The results of this study
indicated that the samples were similar in BW, HT, and BMI, but the wrestlers
had significantly smaller upper body SF values (subscapular and triceps SF)
than the non-athletes. Thus, participation in wrestling had no effects on BW or
HT, but reduced subcutaneous fat levels of the trunk and posterior upper limb.
Practical Applications: Participation in age-group and high school wrestling had
no adverse effects on BW, HT, or BMI. In addition, the wrestlers exhibited positive
subcutaneous fat distribution characteristics when compared to non-athletes.
Poster: 23
BODY COMPOSITION, HEIGHT, AND MASS DIFFERENCES BY SPORT AND SPORT
POSITION IN NCAA-D1 WOMEN ATHLETES
G. L. Coleman1, M. T. Jones1
1
George Mason University
*Award Eligible - Outstanding Master’s Student Poster Presentation
Purpose: The current study was designed to assess body fat (%BF), height (HT),
and mass (WT) in four women’s NCAA-D1 sports: basketball (BB), lacrosse
(LAX), soccer (SOC), and volleyball (VB). The secondary focus was to compare
differences in %BF, HT, and WT across sport positions. Methods: Athletes from
BB (n=63; age=20.3±1.1yr; HT=176.3±6.7cm; WT=71.0±9.6kg), LAX (n=103;
age=20.0±1.2yr; HT=166.3±6.9cm; WT=64.0±7.2kg), SOC (n=91; age=19.6±1.1yr;
HT=165.6±7.0cm; WT=61.1±6.5kg), and VB (n=51; age=20.0±1.0yr; HT=176.5±6.9cm;
WT=68.9±7.7kg) served as subjects. Body composition was analyzed though
use of air displacement plesthymography (BodPod, Cosmed). Sport positions
were categorized as follows: BB – Forward (FOR), Guard (GRD); LAX – Attack
(AT), Midfield, (LMF), Defense (LDF), Goalkeeper (LGK); SOC – Forward (SFOR),
Midfield (SMF), Defense (SDF), Goalkeeper (SGK); VB – Defensive Specialist/
Librero (DSL), Middle Blocker (MBL), Outside Hitter/Right Side (OH), Setter
(SET). Analysis of variance (ANOVA) compared HT, WT, and %BF by sport and
by position within each sport. Alpha level was set at p<0.05. Bonferroni was used
for post hoc analyses. Results: The %BF for BB (20.5±6.3%) was lower (p=0.001)
than LAX (24.4±5.2%), SOC (23.4±5.1%), and VB (25.5±4.4%). BB and VB were
taller (p=0.001) than SOC and LAX. Mass was greater (p=0.001) for BB and VB
compared to LAX and SOC. Within BB, GRD (17.9±6.1%) had lower (p=0.001) %BF
than FOR (22.9±5.6%). BB FOR were taller (p=0.001: 181.6±3.8cm vs. 171.2±4.6cm)
and heavier (p=0.001: 76.2±8.8kg vs. 66±7.4kg) than GRD. Within LAX, LMF
(21.7±4.6%) had lower (p=0.001) %BF than LDF (27.5±5.4%) and LGK (29.2±4.6%). AT (23.5±3.2%) had lower %BF than LDF (p=0.01) and LGK (p=0.009). LMF were
taller than AT (p=0.032: 167.6±7.5cm vs. 162.9±7.8cm). LDF (67.6±6.7kg) were
heavier (p=0.001) than LMF (61.7±4.8kg) and AT (60.2±5.6kg). LGK (74.5±7.5kg)
were heavier (p=0.001) than LMF, AT, and LDF (p=0.015). Within SOC, the SGK
(172.9±7.8cm) were taller (p<0.05) than SFOR, SMF, and SDF. Within VB, MBL
(183.9±1.2cm) were taller (p=0.001) than DSL (167.3±5.3cm), OH (177.9±2.9cm),
and SET (175.8±2.7cm). DSL was the shortest (p=0.001) VB position. Conclusion:
BB consists of short sprints, cutting, jumping, and stopping; actions that favor
having a low %BF. Due to sport demands and position demands, it was expected
that perimeter players (GRD) would have lower %BF than FOR, and that BB would
have less %BF than LAX, SOC, and VB. SOC and LAX are field sports that entail
long, recurring runs up and down the pitch, which place a high demand upon
the cardiovascular system. The AT and LMF positions of LAX require precision
passes and dodges following long sprints with abrupt stopping and restarting.
AT and LMF cover more distance in a game than LDF or LGK, which may explain
their lower %BF. VB posted the highest %BF, which may be more a reflection of
sport demands than fitness level. VB requires the utilization of quick, reactive,
multi-directional movements in a limited space. VB athletes tend to have more
similar body types across sport position than other sports. Practical Applications:
To make comparisons across sports or sport positions is difficult due to the lack of
published data and differing sport demands. Values can be expected to vary from
NCAA divisions to athletic conferences. Monitoring an athlete’s body composition
is crucial because major changes in %BF can be indicative of health concerns. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 24
ASSOCIATION OF BODY COMPOSITION AND AEROBIC FITNESS ON HEART
RATE VARIABILITY AND RECOVERY IN BLACK MEN
R. L. Herron1, S. J. Carter1, H. Williford2, M. Esco2
1
The University of Alabama, 2Auburn University Montgomery
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Heart rate variability (HRV) and heart rate recovery (HRR) are indicators of
cardiovascular autonomic modulation and are noninvasive measures used to
observe physiological changes associated changes in health status or fitness. Previous researches have indicated relationships between body composition,
cardiorespiratory fitness, HRR, and HRV, though the extent of this link remains
unclear. Few studies have considered the interaction of race regarding health
related physical fitness and autonomic modulation. PURPOSE: The purpose of
this study was to determine the extent of variation in HRV and HRR that could be
accounted for by cardiovascular fitness and various measures of body composition,
while controlling for race. METHODS: Fifty adult Black men (22 ± 3 yr) participated
in this study. Each subject rested in the supine position while HRV was recorded
for a 5-min period. To measure HRV, the frequency domain was used to transform
the electrocardiogram into a power spectrum. The normalized area under the
high-frequency (0.15 to 0.40 Hz) component was recorded and analyzed as a
marker of parasympathetic modulation. Waist circumference, BMI, and sum of
skinfolds (7 sites) were used has anthropometric measures of body composition. A graded exercise treadmill protocol was performed to attain VO2max. Immediately
following the exercise test, each subject returned to the supine position to monitor
HRR at 1-min (HRR1) and 2-min mark (HRR2). One-way ANOVA procedures were
used to compare means between subjects. Zero-order correlations were also
used to determine the relationship between the studied variables. The clarify
influences of the variables on the variance in HRV and HRR stepwise multiple
regression procedures were used. RESULTS: The results indicated that HFnu was
lower and LF: HF was higher (P < 0.05) in our lower cardiovascular fitness group
compared to the higher, as designated by the norm-referenced VO2max measure
(above and below the 50th percentile). However when adjusting for BMI, WC,
and SF these differences were not apparent (P > 0.05). Significant correlations
were found between all variables and VO2max. However, VO2max did not correlate
with any parameter of HRV or HRR. BMI and WC provided significant correlations
with HRR (P > 0.05). The stepwise regression procedures showed only SF to
account for the variation in HFnu (R2 = 0.20, P < 0.05) and LF: HF (R2 = 0.30, P
< 0.05). The regression also revealed that WC was the only variable to account
for variation in HRR2 (R2 = 0.20, P < 0.05). CONCLUSIONS: The results of the
investigation suggest that Black men with higher aerobic fitness exhibited greater
HRV. This relationship appeared to be a result of more favorable profiles of body
composition seen in the higher fit group. PRACTICAL APPLICATIONS: The results
of this study underscore the importance of body composition when explaining
the relationship between physical fitness and cardiovascular-autonomic control in
Black men. According to these results, lifestyle interventions should be designed
to improve aerobic fitness and body composition to fully enhance cardiovascularautonomic control in this population.
Poster: 25
SPORT-SPECIFIC TRAINING EFFECT ON YOUNG MALE BASKETBALL
AND SOCCER PLAYERS
T. Jallai1
1
University of Tartu, Estonia
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: The technical and physiological demands of basketball and soccer
games vary greatly. The purpose of this study was to compare anthropometrical
characteristics, body composition, total body mineral density (BMD) and areal
bone mineral density (aBMD), postural control and vertical jumping performance
characteristics in young male players. METHODS: Nine high school basketball
(BB) (age, 16.4 ± 0.5 years; height, 185.5 ± 6.7 cm; weight, 81.9 ± 9.9 kg; % body
fat, 17.4 ± 8.3%) and nine high school soccer (S) (age, 16.0 ± 0.1 years; height,
178.9 ± 8.2 cm; weight, 68.1 ± 7.6 kg; % body fat, 13.6 ± 5.9%) players volunteered
for the study. All athletes were considered healthy and had a history on average
of 8 years of specific training in their sport, 5 times per week and/or 9 hours
per week. Bi- and unipedal static balance testing was performed on the force
platform for 30 s. The vertical jumping tests included 3 sets of squat jumps,
countermovement jumps and drop jumps (40 cm). Body composition and BMD
was determined by dual X-ray absorptiometry (DXA). The proximal part of the
femur was measured in four regions: neck, Ward`s triangle, trochanter and shaft.
Standard statistical methods were used for the calculation of means, standard
error of the means (±SE) and standard deviation (±SD). A Student unpaired t-test
was used to measure differences between groups. Pearson`s product-moment
correlation was determined between anthropometrical, postural control and
vertical jumping characteristics. Statistical significance was accepted at p<0.05.
This study was approved by the Institutional Review Board at The University of
Tartu, Estonia. RESULTS: Statistical differences between the groups were found in
body mass (p = 0,004), lean body mass (p=0,014), body mass index (p=0,039),
BMD (p=0,0003), right femur aBMD (p=0,025), and unipedal static balance results
(right leg, p=0,001; left leg, p=0,003). No significant differences were found in
age, height, years of training, training load, body fat percentage, bipedal static
balance or power development per 1 kg of body mass in vertical jump results.
Interestingly, there was no statistical difference in left femur aBMD between BB
and S group. This means, that soccer players experienced higher mechanical loads
on their left leg. BMD was considered within normal range, but higher than the agematched normative population means value (German data): BB group on average
of 116.1 ± 8.4% and S group 107.0 ± 4.0%. No significant correlation was observed
between static balance and vertical jumping characteristics. The BMD showed
large association with subjects age (r=0.56, p<0.01), height (r=0.53, p<0.05),
body mass (r=0.62, p<0.01), and lean mass (r=0.84, p<0.01). CONCLUSION: First,
regular participation in basketball and soccer practices has a positive effect on
BMD in young males. Second, sport-specific training effect on aBMD differs from
sport to sport, and in skeletal regions. PRACTICAL APPLICATION: This study
illuminates the necessity for strength and conditioning professionals to consider
the demands of different sports, and what effect unequal force distributions
may have on the skeletal integrity of the athlete. Side-to-side, or contralateral
comparisons are recommended for young athletes specializing in one sport. This
study also emphasizes, that muscular power and postural control are separate
capabilities, and need to be developed through different training methods.
Poster: 26
THE RELATIONSHIP BETWEEN AEROBIC POWER, FAT FREE MASS,
AND CROSSFIT PERFORMANCE
B. Kliszczewicz1, R. Snarr2, M. Esco3
1
Auburn University, 2Auburn University Montgomery,
3
Auburn University Montgomery
*Award Eligible - Outstanding Doctoral Student Poster Presentation
CrossFit is a fast growing sport of fitness that not only serves as a form of
competition but as a form of general exercise training. Little is known about this
conditioning program or what factors may influence performance. PURPOSE: The
purpose of this study was to examine variables that my influence the performance
of semi- to well-trained subjects on a named CrossFit workout. METHODS: 7 men
and 3 women (mean age = 27.2 ± 9.6 yrs) who have trained in CrossFit for at least
3 months participated in the study. Each subject had body fat percentage (BF%)
assessed with the use of dual-energy x-ray absorptiometry (DEXA). Subjects
then performed a graded exercise test on a treadmill to determine maximal
oxygen consumption (VO2max). All subjects performed the named CrossFit
workout called “CINDY”, which consisted of as many rounds possible of 5 pullups, 10 push-ups, and 15 air squats in 20-min, which is occasionally performed
in competition. Pearson product correlations were performed to determine the
relationship between the laboratory (i.e., BF% and VO2max) and performance (i.e.,
rounds of CINDY completed) variables. RESULTS: The participants had a mean (±
SD) BF% of 16.6 (± 7.9)%, a mean (± SD) VO2max of 52.9 (± 6.4) ml/kg/min-1, and
a mean (± SD) rounds of CINDY completed 17.6 (± 3.4). There was a significant
correlation found between BF% and the number of rounds of CINDY completed (r=
-.84, p < 0.01). Conversely, there was no relationship between VO2max and CINDY
performance (r= 0.02, p > 0.05). CONCLUSION: The findings of this study suggest
that BF% is a relatively strong predictor of CINDY performance. Conversely, there
was no relationship between VO2max and performance, probably because CINDY
is primarily a muscular endurance-based workout. Due to the many different
types of routines within this unique sport, further investigation is necessary to
better understand the relationship between overall physical fitness and CrossFit
performance. PRACTICAL APPLICATION: This study demonstrates the importance
of BF% in relation to rounds completed of CINDY. However, the significance of
VO2max for CrossFit performance remains unclear.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 27
EVALUATION OF MUSCLE QUALITY RELIABILITY AND RACIAL DIFFERENCES IN
BODY COMPOSITION OF OVERWEIGHT INDIVIDUALS
M. N. Melvin1, A. E. Smith-Ryan2, H. Wingfield3, M. Woessner3, S. Fultz3
1
University of North Carolina at Chapel Hill, 2University of North Carolina
Chapel Hill, 3University of North Carolina
*Award Eligible - Outstanding Master’s Student Poster Presentation
It has been suggested that physiological differences in muscle density and
pennation angle exist between black and white athletes. Echo intensity (EI) may
detect these differences in muscle integrity. Purpose: The purpose of this study
was to investigate the reliability of ultrasound measures of muscle cross sectional
area (mCSA) and echo intensity (EI) of the vastus lateralis (VL) in overweight
subjects. A secondary purpose was to evaluate racial differences in EI, mCSA, and
body composition. Methods: Thirty-three overweight subjects (Age: 39±11 yrs, Ht:
174.1±10.0 cm, Wt: 94.2±15.1 kg, %fat: 32.4±7.1 %) were stratified by race: black
(B; n = 10) and white (W; n = 23). Muscle CSA of the VL was determined from a
panoramic scan of the VL using a GE logiq-e B-mode ultrasound (GE Healthcare).
The ultrasound probe was held perpendicular to the tissue and swept across the
skin at equal pressure from the lateral VL border to medial fascia separation.
Echo intensity was determined from the panoramic scan of the VL by grayscale
analysis using Image-J software. Fat mass (FM), lean mass (LM), and %fat were
determined using dual-energy x-ray absorptiometry (DXA). Reliability of mCSA
and EI was evaluated using intraclass correlation coefficients (ICC), standard error
of the measurement (SEM), standard error of the measurements as a percentage
of the mean (SEM%), and minimum difference (MD). One-way analysis of variance
was used to identify racial comparisons. Results: For mCSA, ICC(2-1), SEM, SEM%
and MD were 0.87, 2.12, 12.65% and 5.89, respectively. For EI, ICC(2-1), SEM, SEM%
and MD were 0.74, 4.58, 9.20%, and 12.69, respectively. Between black and white
subjects, there were no significant differences (p=0.144-0.519) for the body
composition variables FM: (B: 33.4±9.6 kg; W: 28.9±6.9 kg) LM: (B: 63.9±15.9 kg,
W: 59.0±10.5 kg), and %fat: (B: 33.7±8.3 %, W: 31.9±6.6 %) or for mCSA (p=0.841;
B: 16.6±9.3 cm2, W: 16.0±5.1 cm2). However, EI was significantly lower (p=0.018)
for black (45.7±10.3) than white (53.5±7.2). Conclusions: Ultrasound measures
of mCSA and EI are reliable in overweight subjects. There were no significant
differences in mCSA or DXA body composition measurements between the black
and white overweight individuals, but there was a significant difference in EI.
Lower EI in overweight black individuals may suggest that black athletes have
decreased intramuscular adipose and connective tissue, decreased pennation
angle, and increased muscle density when compared to overweight white athletes.
Practical applications: These results suggest that EI may be a better indicator
of obesity-related health risks than DXA %fat. Measurements of EI in overweight
athletes may provide better risk indicators for sarcopenic obesity and metabolic
syndrome, which may help provide a more effective transition into retirement.
Acknowledgements: Supported by funding from the Nutrition Obesity Research
Center (P30DK056350).
Poster: 28
RELATIONSHIP OF REGIONAL AND TOTAL LEAN MASS TO ISOINERTIAL LIFTS
IN COLLEGE FOOTBALL PLAYERS
R. Schumacher1, J. Ramatowski1, B. Mann2, J. L. Mayhew1
1
Truman State University, 2University of Missouri
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
One-repetition maximum lifts (1RM) have long been the choice of strength and
conditioning specialists to evaluate strength potential of college football. In
addition, body dimensions and lean body mass have been used as adjunct
correlates to strength performance. However, little attention has been given to
the generalizability among strength tests or the potential of body composition
elements to assist in identifying strength potential. PURPOSE: To evaluate the
relationship of regional and total lean mass to 1RM isoinertial performances in
college football players. METHODS: 66 NCAA Division II college football players
(age = 20.4 ± 1.2 yrs, height = 181.5 ± 6.6 cm, body mass = 97.8 ± 17.6 kg) were
evaluated for 1RM performances in bench press (BP), squat (SQ), deadlift (DL),
and hang clean (HC). Players also performed maximal bench repetitions with a
constant load (NFL-225 test). In addition, regional lean tissue mass was determined
for arms, trunk, legs, and total body from dual-energy X-ray absorptiometry (DXA;
lunar?...). RESULTS: BP was significantly related to SQ (r = 0.389, p<0.001), DL (r
= 0.614, p<0.001), and HC (r = 0.328, p<0.001). DL was significantly related to HC
(r = 0.513, p<0.001) but not to SQ (r = 0.147, p = 0.26). SQ was negatively related
to HC (r =-0.569, p<0.001). Factor analysis produced 2 strength components, with
BP and DL accounting for 48.3% of the total variance, and SQ and HC accounting
for 39.3%. Regression analysis indicated that only total lean mass was moderately
predictive of BP (r = 0.53, SEE = 16.1 kg) and DL (r = 0.55, SEE = 21.7 kg). Regional
lean mass did not significantly predictive of SQ or HC. NFL-225 repetitions were
highly related to 1RM BP (r = 0.93, p<0.001) and, to a lesser degree, to SQ (r =
0.43, p<0.001), and DL (r = 0.46, p<0.001). Regional and total lean masses made
no significant (p>0.80) contribution to lift prediction beyond NFL-225 repetitions. Repetitions were not significantly related to HC (r = 0.19, p = 0.19). CONCLUSION: Regional and total lean masses appear to make relatively small contributions to
the prediction of 1RM strength performances in college football players. Major lifts
may be independent of one another, suggesting a lack of strength generalizability
with less than 38% common variance among the lifts. PRACTICAL APPLICATION: Strength and conditioning specialists may have to consider an array of strength
tests to evaluate regional or total body strength. Neither regional nor global body
composition appears to be of much value in identifying specific or total strength
performance in college football players. Poster: 29
SELF DIRECTED LEARNING, DEPRESSION, ANXIETY, AND
STRESS IN ULTRA-ENDURANCE ATHLETES
B. Gentry1, L. Van Ginder2, T. J. Piper3, C. McMillian2
1
Western Illinois University, 2Western Illinois University, 3Western Illinois
University, Department of Kinesiology, Major of Exercise Science
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Purpose: The purpose of this study was to investigate the self-directed learning
characteristics and the levels of depression, anxiety, and stress present in ultraendurance racing participants. Methods: Fifteen participants (male=13, female=2,
mean age=30.7±9.36 years, age range=20-47) enrolled in the event were surveyed
using the Oddi Continued Learning Inventory (OCLI) and the Depression, Anxiety,
and Stress Survey (DASS). Subjects’ prior frequency of training leading up to
the race just over 2.5 days per week (M= 2.67±0.89) with a range of average
training sessions from 30-60 minutes to +120 minutes. Subject’s average longest
training session in preparation for the race exceeding 500 minutes in total (M=
516.67±477.47 minutes) with scores ranging from 90 minutes to 1800 minutes.
Subject’s education level ranged from High School to Bachelor’s Degree, mean
falling between an Associate’s and Bachelor’s Degree. The official title of the event
was “The Suck” and consisted of a wide range of challenges and obstacles with no
specific emphasis on one discipline of fitness. This event was 36 hours in duration. “The suck” is a military term that defines any situation where conditions are
undesirable and is a testament to the dedication of those who endure it. Results:
The overall results of the OCLI scores ranged from 101-149. The average score
among the racers was 127 (M=127±13.3). These results are consistent with past
research utilizing the OCLI, indicating that these participants possess a high level
of SDL. Results from the DASS for depression ranged from 0-4, for anxiety 0-22,
for stress 0-16. For depression the average was 1.067 (M=1.067±1.6), for anxiety
the average was 4.267 (M=4.267±6.5), for stress the average was 9 (M=9±5.8).
These results showed low levels of depression, anxiety, and stress prior to the race
in these participants. Conclusion: This study revealed that those that participate
in ultra-endurance obstacle races tend to be self-directed learners and have low
levels of depression, anxiety, and stress prior to the race. Practical Applications:
Considering the level of SDL present in these participants it is clear that these are
individuals who take control of their individual training goals and are purposeful
in their learning. The participants showed very low levels of depression, anxiety,
and stress, which concludes that these individuals were mentally prepared for a
high demanding race.
Poster: 30
ENDURANCE TRAINING PREVALENCE AND PREFERENCE AMONG
COMPETITIVE MOUNTAIN BIKERS
S. M. Mitchell1, M. Richardson2, J. C. Higginbotham2, H. Gary2, J. Wingo2,
S. Usdan2, R. Henderson2
1
University of South Alabama, 2University of Alabama
*Award Eligible - Outstanding Doctoral Student Poster Presentation
VO2max has been identified as a physiological contributor to mountain bike
performance. Research supports endurance training (ET) as a modality for
increasing VO2max. While studies have examined the physiological parameters
associated with successful riding, little is known about how competitive mountain
bikers train to increase performance. PURPOSE: Therefore, the purpose of this
study was to identify the prevalence of traditional ET among competitive mountain
bikers in their effort to improve performance. METHODS: Forty competitive
mountain bikers (mean + SD, age 25.75 + 9.12 years) responded to an online
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
training survey. Participants for this study were recruited by contacting groups
whose members are competitive mountain bikers (i.e., NCAA university teams,
university sports club teams, sponsored teams, professional teams). The survey
assessed several types of training, including ET. Major responses were examined
to determine the reliability of the training survey. Cronbach’s alpha value for
reliability was 0.82. RESULTS: In-Season: Proportion of respondents participating
in ET during the in-season was 97.5%. Seventy-two percent of riders reported trail
riding only, 28% used a stationary cycle ergometer to complement trail riding, and
no riders reported using a cycle ergometer only for ET sessions. Mean number
of weekly trail riding endurance sessions was 2.51(SD=1.44) sessions. Workout
sessions per week on a stationary cycle ergometer were 1.73(SD=0.79) sessions.
Paired samples t-test revealed a significant difference between the weekly
number of trail sessions and cycle ergometer sessions (t=2.65, df=10, p=0.02). OffSeason: Proportion of respondents participating in ET during the off-season was
82.5%. The percentage of riders who participate in ET during the in-season was
significantly greater than that during the off-season (z=2.58, p=0.005). Fifty-two
percent reported trail riding only, 33% reported trail riding and a cycle ergometer,
and 12% reported using a cycle ergometer only for ET sessions during the offseason. Median number of weekly endurance sessions spent trail riding was 2
sessions. Median number of workout sessions per week on a cycle ergometer was
2 sessions. A Wilcoxon signed rank test revealed no significant difference between
the weekly number of endurance trail sessions and cycle ergometer sessions during
the off-season (z=-0.30, p=0.78). CONCLUSION: Among respondents, 97.5%
reported participating in ET during the in-season, while 82.5% reported ET during
the off-season. Based on the perception that mountain biking is an aerobically
based event, these results may not seem surprising. A greater percentage of
riders chose trail riding as a modality for endurance training and more sessions
of trail riding were conducted per week during the in-season when compared
to a cycle ergometer. These results suggest that riders may prefer to train on
equipment specific to competition. There is also the possibility that riders simply
enjoy riding their bikes on a trail and choose to trail ride for training. PRACTICAL
APPLICATIONS: ET has been shown to increase aerobic capacity, which may lead
to increases in performance while riding. Trail riding offers the rider a training
environment almost identical to an actual competition, as well as training on the
type of equipment they will use in competition. Riders appear to prefer trail riding
as a means for improving aerobic capacity. If not already doing so, coaches should
consider implementing a greater number of trail rides when looking to increase
performance among their athletes. Poster: 31
EFFECT OF BETWEEN-INNING MUSCLE STIMULATION ON BASEBALL PITCHERS
OVER AN ENTIRE SEASON: A PILOT STUDY
J. Blaum1, D. Szymanski1, C. Warren2
1
Louisiana Tech University, 2Center for Athletic Performance
and Physical Therapy
*Award Eligible - Outstanding Master’s Student Poster Presentation
PURPOSE: To record live game effects of between inning muscle stimulation
on shoulder strength, shoulder range of motion (ROM), and pitching velocity
(PV) throughout a collegiate baseball season. METHODS: Eleven Division I
intercollegiate baseball pitchers volunteered for this study. Four pitchers were
placed in the muscle stimulation (experimental) group while 7 pitchers were in
the active rest (control) group. The muscle stimulator (DJO Global Inc., Vista, CA,
USA) was used in the experimental group. All participants were medically cleared
by team physicians prior to being involved in the study. Pitchers in the experimental
group had the muscle stimulator pads placed on 8 locations on the throwing
arm side (medial and lateral forearm, biceps and triceps, anterior and posterior
shoulder, and trapezius and latissimus dorsi) in between every inning they pitched
during the season. Pitchers in the active rest (control) group sat in the dugout as
they normally would in between innings. Pre-season shoulder ROM (goniometer)
and strength (Jamar dynamometer) measurements (flexion, extension, internal
rotation at 90°, and external rotation at 90°) and PV (Stalker radar gun) were
recorded in February prior to the first game. Pitching velocity was recorded
during every home game while ROM and strength measurements were measured
early mid-season, late mid-season, and post-season. A 2 x 4 (group x season)
repeated measures ANOVA was run on each dependent variable to measure
significance. Statistical significance was set an alpha level of p ≤ 0.05. RESULTS:
Internal rotation (IR) strength was significantly different between the two groups
when measured early mid-season (p = 0.04). The rest of the measurements
throughout the study were not significantly different at the p ≤ 0.05 level. The
mean PV for the control group was not statistically different than the mean PV for
the experimental group at any time during the season. CONCLUSIONS: The most
important finding of this study was that the use of the muscle stimulator between
innings during the season did not improve baseball pitcher’s ROM or PV. However,
IR strength was significantly different at early mid-season. In discussions with the
experimental group, they agreed that they felt less discomfort throughout the
game and during the days after pitching in comparison to when they did not use
the muscle stimulator. A major limitation of this study was the sample size and the
device used to measure shoulder strength. PRACTICAL APPLICATION: In between
inning uses of a muscle stimulator during actual baseball games throughout an
entire season showed no significant differences in pitcher’s shoulder ROM or, in
general, shoulder strength between groups. However based on the feedback from
the muscle stimulator group, pitchers believed that use of the muscle stimulator in
between innings provided a comfort level during the game that helped them stay
“warm” in between innings. They believed that this allowed them to get back to
optimal throwing comfort easier before the next inning started.
Poster: 32
ACUTE EFFECTS OF STATIC STRETCHING, DYNAMIC STRETCHING, AND FOAM
ROLLING PRIOR TO SIT AND REACH TEST, VERTICAL JUMP, AND STANDING
LONG JUMP
M. Genin1, R. Rozenek2, D. Young2, L. Wilson3
1
California State University Long Beach, 2CSULB, 3Northern Arizona University
*Award Eligible - Outstanding Master’s Student Poster Presentation
PURPOSE: It has been suggested that a warm-up consisting of dynamic
stretching may have a greater benefit in exercise performance when compared to
static stretching. These two modes of warm-up have not yet been compared to
self-myofascial release with the use of a foam roller. There has been insufficient
research on the effect of foam rolling, however claims by fitness professionals and
coaches assume that this modality may have an effect on performance. Identifying
a relationship between self-myofascial release and performance would be of great
benefit to those utilizing this modality. The purpose of this study was to examine
the acute effects of static stretching, dynamic stretching, and foam rolling prior to
the sit and reach test, vertical jump, and standing broad jump. METHODS: Seventy
two college-aged, untrained subjects (38 males, 34 females) performed static
stretching (SS), dynamic stretching (DS), self-myofascial release with a foam roller
(FR), and no warm-up prior (C) to the sit and reach test (SR), vertical jump (VJ),
and standing broad jump (SBJ). This was a randomized, within-subject study. The
order of the warm-up protocols and tests were randomly assigned. The first session
consisted of the warm-up protocols and jump tests familiarization. The testing
was performed in four visits, once or twice per week. Each testing session began
with a general warm-up of easy jogging for five minutes at a self-selected pace. Immediately after the jog the subject performed three trials of the SR, followed
by one of the four warm-up interventions including (a) SS, (b) DS, (c) FR, or (d)
C. Subjects then performed three SR trials immediately after the experimental
condition. Three trials of both the VJ and SBJ tests were performed in random
order after the second set of SR trials. A post-test questionnaire was administered
at the end of each of the four testing sessions to gain subjective feedback about
the warm-ups. RESULTS: Data was analyzed using a one-way repeated measures
analysis of variance. The difference in pre and post warm-up SR measurements
were statistically significant (p = 0.000) following SS, DS, and FR in comparison
to C. There were no significant effects in VJ height (p = 0.995), or in SBJ length
following any of the warm-up protocols (p = 0.820). CONCLUSIONS: The findings
of this study show that SS, DS, and FR did not improve vertical jump, or standing
broad jump performance over the control. There were significant improvements
in the sit and reach test between pre and post-test measurements following SS,
DS, and FR when compared to C. Factors that may have influenced these results
include duration and intensity of the warm-up protocols, training status of the
subjects, as well as using different performance measures. It was concluded that
SS, DS, and FR have no acute effects on jump performance, but may increase
low back and hamstring flexibility. PRACTICAL APPLICATIONS: Static stretching,
dynamic stretching, and foam rolling may be beneficial prior to exercise where
flexibility is pertinent to performance. However, these methods of warm-up may
not be beneficial prior to power exercises that including jumping. More research
on foam rolling prior to endurance and strength performance is recommended. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 33
SELECTED PREDICTORS OF CHAMPIONSHIP CROSS COUNTRY RUNNING TIMES
IN MALE AND FEMALE COLLEGIATE CROSS COUNTRY RUNNERS
J. Miller1, E. Agre1
1
Oklahoma City University
PURPOSE: The purpose of this study was to identify important performance
predictors of race time (RT) for a mens and womens cross country conference
championship race. METHODS: Four female (age=21±4yrs; height = 67±3in; weight
= 123±11lbs) and six male (age=18.1±0.4yrs; height = 70±2in; weight = 145±12lbs)
collegiate runners that participated in a NAIA D-1 level conference championship
volunteered for the study. Participants reported for testing within one week of
the championship race. Following a 10min warm up period on a cycle ergometer,
athletes were assessed for lower body strength by the squat jump (SJ), lower
body neuromuscular power by the vertical jump (VJ), static trunk endurance by
the prone (PP), right (RP)and left (LP) plank hold times, and passive ankle range of
motion by right (RDF) and left (LDF) passive ankle dorsiflexion (PAD). SJ: Hands
were placed on the hips, and the participants achieved/held a parallel squat for
4 sec before jumping. VJ: Participants were permitted to use a countermovement
and arm swing. Athletes performed as many jumps as necessary until two
successive jumps were no longer higher than the best recorded score. A 30 sec
rest was observed between all jump assessments/attempts. All jump assessments
were conducted on a contact mat (Just Jump, Probotics, Huntsville, AL). Following
a 3 min rest, the planking assessments were conducted with the PP first followed
by the RP or LP; the order of the RP and LP alternated with each participant.
Participants were given one chance to correct during each plank and 1 min rest
between bouts of planking. PAD was conducted after the planking assessments.
Participants placed the knee of the selected leg against the wall while sliding the
heel away from the wall until just before the heel lifted. Distance from the posterior
side of the heel to the wall was recorded for both legs utilizing a tape measure
placed on the floor perpendicular to the wall. PAD scores were normalized to the
participants’ height. The difference (DD) between PAD scores for the right and left
leg was calculated. Men’s race distance was 8k (28.1±0.24min) and the women’s
5k (20.5±0.5min). The relationships between the predictor scores and RT were
assessed using a Pearson (r) product-moment correlation coefficient. RESULTS:
For the men, strong and moderate strength relationships existed between race
time and the SJ (r = -0.69), VJ (r = -0.52), DD (r = -0.45), LDF (r = -0.54), and RDF
(r = -0.72). For the women, strong and moderate strength relationships existed
between race time and the SJ (r = -.69), VJ (r = -0.63), PP (r = -0.70), RP (r =
-0.75), LP (r = -0.79), DD (r = 0.73), and RDF (r = -0.50). CONCLUSIONS: Male and
female collegiate cross country athletes could improve running performance by
increasing leg strength (SJ), neuromuscular power (VJ), and passive ankle range
of motion. Female athletes may also improve running performance through an
increase in static trunk endurance. PRACTICAL APPLICATION: For both the male
and female athletes an increase in lower body strength and muscular power could
provide improved running economy, while increased PAD could create greater
impulse from longer foot contact time. Female collegiate cross country athletes
might benefit from static trunk training possibly to provide better force transfer
from hip extensors and hip abductors through the lower extremity into the running
surface.
Poster: 34
EFFECTS OF PNF STRETCHING FOLLOWING CRUSHED ICE VERSUS
WETTED ICE ON HAMSTRING FLEXIBILITY
M. Miller1, J. Troiano1, C. Larsen1, R. Ramirez1, W. Holcomb2
1
Western Michigan University, 2The University of Southern Mississippi
*Award Eligible - Outstanding Master’s Student Poster Presentation
Flexibility, which is the ability to move freely through a full range of motion (ROM),
is desired to improve performance and decrease the likelihood of muscle injury. Proprioceptive Neuromuscular Facilitation (PNF) stretching is recognized as the
most effective stretching technique to improve flexibility. In addition, cryotherapy
has been shown to enhance stretching for greater improvements in flexibility. Recent research has shown that wetted ice (ice bag with added water) is a superior
form of cryotherapy. However, no study was found that combined either crushed
or wetted ice with PNF stretching on hamstring ROM. PURPOSE: To determine
which type of cryotherapy agent, crushed or wetted ice bag, would produce the
greatest gains in hamstring ROM when followed by PNF stretching. METHODS:
Fifteen healthy subjects aged 22.6 ± 1.6 years with no history of lower leg
pathologies or sensitivity to cryotherapy volunteered to participate. Each subject
underwent three testing sessions with treatment order counter-balanced. The
three treatment conditions were: crushed ice bag (crushed ice), wetted ice bag
(wetted ice) and no ice bag (no ice). The crushed ice consisted of 2500mL of ice
placed in a 9.5in by 18in 1-mil polyethylene Cramer® bag with the air removed to
increase conformity to the hamstring. The wetted ice bag contained 2500mL of
cubed ice along with 150mL of room temperature water in the same sized ice bag. The subject’s baseline hamstring ROM was measured (baseline) with a goniometer
followed by one of the twenty minute treatment sessions. At the conclusion of the
treatment session, a second ROM measurement was taken (pre-PNF). Subjects
were then stretched using a slow-reversal-hold-relax PNF technique consisting
of a ten-second passive stretch, a ten-second isometric contraction and then
a final thirty-second passive stretch. Following PNF stretching, a final ROM
measurement was taken (post-PNF). A repeated measures analysis of variance
(RM-ANOVA) was used to analyze the differences in the time period (baseline,
pre-PNF, post-PNF) and treatment condition (wetted, crushed, no ice) on the ROM
of the hamstring. RESULTS: The RM-ANOVA showed that there was a significant
interaction effect (F(4,56)=5.32, P=.001) between the time periods and condition.
Post hoc testing indicated that no ice (75.49° ± 12.19°) was significantly different
than wetted ice (81.73° ± 10.34°) and crushed ice (81.62° ± 13.19°) at the pre-PNF
period. The post-PNF stretching period showed that no ice (85.27° ± 13.83°) was
significantly different than wetted ice (89.44° ± 11.31°) and crushed ice (89.16° ±
13.78°). However, post-PNF ROM between wetted ice and crushed ice were not
statistically different. CONCLUSIONS: Using cryotherapy prior to PNF stretching
enhances the improvements in hamstring flexibility. However, under the conditions
of this study the type of cryotherapy used did not affect the results. PRACTICAL
APPLICATIONS: Strength and Conditioning Coaches can provide a greater
increase in hamstring flexibility by applying ice prior to PNF stretching and those
who have lost flexibility due to injury can see greater improvements in ROM while
also receiving the therapeutic benefits of cryotherapy.
Poster: 35
TEST-RETEST RELIABILITY OF MUSCLE AND TENDON LENGTHS: AN
ULTRASOUND TAPE MEASURE APPROACH
M. Scharville1, E. D. Ryan2, E. J. Sobolewski2, J. Rosenberg1,
G. E. King2, B. J. Thompson3
1
University of North Carolina at Chapel Hill, 2The University of
North Carolina at Chapel Hill, 3Oklahoma State University
*Award Eligible - Outstanding Master’s Student Poster Presentation
PURPOSE: The popularity of ultrasound (US) devices to examine muscle
architecture has increased due to its ease of use and portability. A novel technique
using an ultrasound tape measure (US-tape) method has recently been used to
examine the influence of contracture on tendon and muscle lengths. However,
the consistency of these assessments warrants further investigation. The purpose
of the present study was to determine the test-retest reliability for Achilles
tendon (AT) and medial gastrocnemius (MG) length assessed using the US-tape
method. METHODS: Seventeen healthy and recreationally active males (mean ±
SD age, 20.9 ± 2.2; stature, 173.6 ± 6.6 cm; mass, 76.1 ± 13.8 kg) volunteered for
this investigation. Participants visited the laboratory on two separate occasions
separated by 2 - 7 days at the same time of day (± 2hrs). All participants were
seated in a dynamometer with their leg fully extended and at a neutral ankle joint
angle (90° between foot and leg). A Gulick anthropometric tape measure was
fixed to the B-mode US probe. Muscle-tendon unit (MTU) length was measured
from the insertion of the AT on the calcaneus to the superficial aspect of the medial
femoral condyle (tape distance plus US image distance). AT length was measured
from the insertion on the calcaneus to the musculotendinous junction (tape
distance plus US image distance). All measurements were performed by the same
investigator. Following data collection, the US depth and distance was calculated
using Image-J software. MTU and AT lengths were calculated using Pythagoras
theorem and MG length was calculated from the difference between the MTU and
AT lengths. Test-retest reliability for AT and MG lengths were determined using
the intraclass correlation coefficients (ICC), standard error of measurement (SEM),
and minimum difference (MD) values from Model 2,1 per the recommendation of
Weir (2005). Systematic error was examined using separate one-way repeated
measures analyses of variance (ANOVAs). RESULTS: Test-retest reliability statistics
are presented in this study. CONCLUSIONS: The ANOVAs indicated that there was
no systematic error between trials. Relative consistency was high with ICC values
ranging between 0.90 - 0.93 and the absolute consistency values were low with
SEM values (expressed as a percentage of the mean) of 3.15 and 2.54% for AT
and MG length, respectively. Minimal changes to be considered real for AT and
MG lengths were 1.78 and 1.73 cm, respectively. These findings demonstrate that
the US-tape method is a simple and reliable method for determining AT and MG
lengths. PRACTICAL APPLICATION: The US-tape method may be an appropriate
and reliable technique for future studies to examine the acute and chronic
influences of various training routines on tendon and muscle lengths. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 36
PERCEIVED RECOVERY IN MAXIMAL EFFORT STRENGTH TRAINING USING
POWERLIFTS
N. T. Theilen1, B. I. Campbell2, M. C. Zourdos3, J. M. Oliver4, J. Wilson5,
J. O’Halloran2, N. Asher2
1
University of South Florida, 2University of South Florida/Exercise and
Performance Nutrition Laboratory, 3Florida Atlantic University, 4Department of
Kinesiology, Texas Christian University, Fort Worth, TX, 5University of Tampa
Fatigue is manifested following an acute bout of powerlifting (squat, deadlift,
and bench press). One’s perception of recovery may correlate to the individual’s
ability to complete work in the form of powerlift training. The perception of
recovery following intense training using all three powerlifts has not yet been
investigated. PURPOSE: To assess the perceptual levels of acute neuromuscular
fatigue caused by each powerlift as a result of maximal effort strength training
sessions with each powerlift. METHODS: Twelve resistance trained males (22.8
± 2.6 yrs; 177.1 ± 6.7 cm; 83.0 ± 12.6 kgs) participated in a randomized crossover
design with 3 conditions: Squat (SQ), Bench Press (BP), and Deadlift (DL). A
Perceived Recovery Scale (1-10 scale on subjective performance ability) was
used prior to each session to assess individual fatigue. Baseline measures of
perceived recovery were recorded 1 week prior to training. Subjects trained
the Monday of 3 consecutive weeks using each power lift separately (1 lift per
week). Perceived recovery measurements were assessed at 24, 48, and 72 hours
following each training session. Recovery measures were compared to baseline
measures to assess fatigue. Data was analyzed via repeated measures ANOVA
(p<.05). RESULTS: SQ: perceived recovery significantly decreased following squat
training at all three time periods as compared to baseline (Baseline = 8.5; 24
hours = 5.9 [p = 0.013]; 48 hours = 6.3 [p = 0.003]; 72 hours = 7.2 [p = 0.033].
BP: Perceived recovery significantly declined at 24, and 48 hours following BP
training as compared to baseline (Baseline = 8.5; 24 hours = 6.7 [p = 0.007]; 48
hours = 5.6 [p = 0.003]). No significant differences in perceived recovery at 72
hours following bench press training as compared to baseline. DL: no significant
differences in perceived recovery at 24, and 72 hours following deadlift training as
compared to baseline. Perceived recovery significantly declined only at 48 hours
following the deadlift intervention (Baseline = 8.5; 48 hours = 6.6 [p = 0.002].
CONCLUSIONS: Perceived recovery was significantly decreased for 24, 48, and
72 hours following intense squat training. Perceived recovery was significantly
decreased at 24, and 48 hours following intense bench press training. Perceived
recovery was significantly decreased at 48 hours following intense deadlift
training. PRACTICAL APPLICATIONS: There was a significant decrease in the
subject’s perceived recovery status after squat training for a longer period than
bench press and deadlift training. Because perceived recovery and the ability to
perform physical work may be correlated, individuals may need to consider the
effects of each powerlift on perceived recovery and how it may affect subsequent
training or performance days following training. ACKNOWLEDGEMENTS: This
investigation was supported by Dymatize Nutrition Sport Performance Institute. Poster: 37
EFFECTS OF RESISTANCE EXERCISE ON A NOVEL GROWTH HORMONE ASSAY
SIGNAL IN MEN
B. Comstock1, C. Dunn-Lewis1, D. Hooper1, T. Szivak1, S. Flanagan1, D. Looney1, J.
Maladouangdock1, W. DuPont1, D. McDermott1, H. Luk1,
R. Staron2, W. J. Kraemer1
1
University of Connecticut, 2Ohio University
PURPOSE: Growth Hormone is a family of hormones that is a greatly
heterogeneous polypeptide hormone with more than 100 different variant
forms presently known to exist in circulation. The purpose of this study was to
examine the effects of resistance exercise on different growth hormone signals in
response to heavy resistance exercise. METHODS: Eleven healthy non-resistance
trained men n=11; mean ±SD: age 20.7± 2.9 years, 179.6± 7.4 cm performed a
resistance training workout with blood samples obtained pre and post exercise. The resistance training workout consisted of performing three sets with 2 min rest
and a 9-11 RM zone range leg press, squat and knee extensions. Blood samples
were obtained pre- and immediate post (IP) and 15 min post workout for analysis
of serum growth hormone (GH) using two different assay techniques, a bioactive
(BA) and immunoreactive (IR). The bioactive GH assay was determined via a
rat lymphoma cell line Nb-2 bioassay. Prior to each assay, cells were cultured in
RPMI media containing 10% fetal calf serum (FCS) at 37 C in an environment of 5%
C02 of a Forma Scientific incubator. For each assay, cells cultures were split for
continued growth in RPMI and 10% FCS at a concentration of 100,000 cells per ml
for limitation of 72 hours. The remainder was washed twice at 1200 rpm in RPIm
with 1% FCS and incubated in this media known as assay media for 24 hours prior
to the assay. After 24 hours, the samples were pulsed with a mixture of 50 ul
3H thymidine per 2 ml of assay media warmed up to 37° C and incubated in the
incubator for 16 hours. Following the incubation period, cells were harvested on
glass/paper filter mats and allowed to dry overnight and counted on a Beta Plate
Scintillation counter and subsequent values determined via computer interface. A
monoclonal radioimmunoassay (RIA) was used to determine the amount of
immunoreactivity in each of the samples for determination of immunoreactive
GH using standard RIA assay methods using a gamma counter and on-line data
reduction system. A two-way analysis of variance (2 X 2; assay type X time)
was used to determine assay and exercise effects with significance defined at P ≤ 0.05. RESULTS: No differences were observed in the GH concentrations
between assays at rest BA 3.7±0.8 µg●L-1 versus IR 1.2±0.5 8 µg●L-1. There
was a significant increase in both the BA and IR GH concentrations in the blood
following the workout. However, interestingly the magnitude of the BA increase
was magnitude higher than the IR GH assay signal ( BA IP 13.1±1.3 µg●L-1 15 min62.2±12.5 µg●dL-1 versus IR IP 7.7±0.9 µg●L-1 and 15 min-22.2±9.0 µg●L-1 ). CONCLUSIONS: Not all assays will represent that same magnitude of pituitary
release of GH and higher level aggregate. Resistance exercise including whole
body lifts increase pituitary release of GH and the magnitude of its effect may
not be truly represented by just the IR assay responses. However, different
than other bioactive assays, the Nb-2 bioassay responded in a similar manner.
PRACTICAL APPLICATIONS: Theses data underscore the basic premises of GH as
an anabolic responder to resistance exercise and indicate that the concentrations
available for target receptor interactions may be underestimated with the use of
only an IR assay analysis of blood responses. Receptor variation may also be
involved with effects on aggregate monomers rather than just the 22 kD monomer
representative of the IR assay signal. Poster: 38
THE EFFECTS OF ENDURANCE EXERCISE TRAINING ON PLASMA
CONCENTRATIONS OF PROENKEPHALIN PEPTIDE F AND EPINEPHRINE
C. Dunn-Lewis1, B. Comstock1, D. Hooper1, T. Szivak1, S. Flanagan1, D. Looney1,
A. Sterczala1, E. Webster1, A. Bryce1, J. Maladouangdock1, C. Giacchino1,
D. McDermott1, W. J. Kraemer1
1
University of Connecticut
The adrenal medulla is a primary source of peripherally synthesized and released
proenkephalin fragments and catecholamines, primarily epinephrine The purpose
of this investigation was to examine the training-related changes in plasma
concentrations of proenkephalin Peptide F and epinephrine in response to graded
exercise stress to determine if exercise training induces alterations in the pattern
and magnitude of circulating concentrations of these hormones. METHODS:
Sixteen healthy men (22.4±4.1 yrs;179.6±7.3 cm 72.3±6.3 kgs) were matched (body
size, age) and randomly assigned to one of two groups which either performed
high intensity endurance training [E] (n=8) or were asked to remain just normally
active (NA) (n=8) over three months. A graded treadmill exercise test with blood
samples obtained at pre-exercise, and at 25%, 50%, 75% and 100% of VO2max and
immediately post and 15 minutes post exercise. Plasma proenkephalin [107-140]
Peptide F immunoreactivity and epinephrine concentrations were examined pretraining (T-1), and after 4- (T-2), 8- (T-3), and 12-weeks (T-4) of training. A twoway ANOVA with repeated measures and Tukey post-hoc analysis was use to
determine changes in exercise and training responses. Significance was defined
as P ≤ 0.05. RESULTS: Increases were observed in plasma epinephrine at 50%,
75%, 100% and IP with exercise over each of the training time points for the NA
group. With training the E group by T-4 first saw an increase in epinephrine at
75% of maximum and values for epinephrine were significantly higher than the
NA at 100% and IP time points. For plasma peptide F the NA group increased
concentrations at at 75% and 100% and IP and 15 minutes following the treadmill
exercise with no differences observed over time. Conversely, the E group shifted
their response pattern which was identical to the NA at T-1 and T-2 with training
with the increase in Peptide F concentrations at 50% at T-3 and T-4 during the
graded exercise test with the concentrations being significantly higher than the
NA at this time point and significantly lower at the 100% time point at these
training times. Recovery values were also significantly higher at 15 minutes post
exercise for the E compared to the NA group. CONCLUSIONS: This study indicates
the plasma concentrations of Peptide F and epinephrine in response to graded
exercise can be differentially altered with endurance exercise training and reflect
what has been seen in elite endurance athletes with higher adrenergic responses
to maximal exercise and a quicker response of opioid peptides at submaximal
exercise intensities. PRACTICAL APPLICATIONS: These data indicate that the
adrenal medulla is trainable and earlier increases in opioid peptides might allow
for an analgesic effect to allow for the higher adrenergic response to maximal
exercise. Additionally, the higher recovery responses of Peptide F in the E group
may represent, as has been noted in the literature, a great immune interactive
enhancement for recovery purposes after maximal exercise. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 39
EFFECTS OF ACUTE RESISTANCE EXERCISE AND SHORT-TERM TRAINING ON
BIOACTIVE PROLACTIN RESPONSES IN MEN
S. Flanagan1, C. Dunn-Lewis1, B. Comstock1, D. Hooper1, T. Szivak1, D. Looney1,
W. DuPont1, E. Webster1, A. Bryce1, H. Luk1, D. Dombrowski1,
C. Giacchino1, D. McDermott1, R. Staron2, W. J. Kraemer1
1
University of Connecticut, 2Ohio University
PURPOSE: Over the years little has been know about the role of prolactin in men. Few data exist as to the responses of the larger prolactin molecule measured
with a bioassay. The purpose of this study was to determine if the bioactive
prolactin molecule was differentially sensitive to resistance exercise or with
short term training adaptations. METHODS: Sixteen men n=21; mean ±SD: age
21.7± 2.9 years, 176.6± 6.4 cm participated in an 8-week were randomly assigned
of one of three groups including two progressive resistance training programs
i.e., low rep n=9 performing 3-5 repetitions maximum (RM) for four sets of each
exercise with 3 min rest between sets and exercises or a high repetition group
(high rep, n=7) performing 20-28 repetitions RM for two sets with 1 min rest or a
non-exercising control group (con n=5). Lower body workouts were performed
(leg press, squat and knee extension) were performed 2 days/week for the first
4 weeks and 3 days/week for the final 4 weeks. The programs were designed
to be equal in volume (resistance X repetitions X sets). Blood was sampled pre
and immediately post-workout pre and post-training. Bioactive prolactin (large
form) was determined via a rat lymphoma cell line Nb-2 bioassay. Each assay
96 well Croning culture plate contained one 12 point standard curves-two rows
for human prolactin. Each curve was proceded with a well of naked FCS, serving
as a maximal growth control or background. The serum samples were analyzed
in duplicate with 2.5 ul pipeted into each well. In addition, to the sample a 17.5
ul of assay media for a 1:8 dilution needed to keep the sample reading within the
standard curve was also assayed. The last row of each plate contained 20 ul of
B7 rat prolactin as an internal standard. Each plate was incubated for 24 hours
at 37 and 5% Cos in the incubator. After 24 hours, the samples were pulsed with
a mixture of 50 ul 3H thymidine per 2 ml of assay media warmed up to 37 C and
incubated in the incubator for 16 hours. Following the incubation period, cells were
harvested on glass/paper filter mats and allowed to dry overnight and counted on
a Beta Plate Scintillation counter and subsequent values determined via computer
interface. Data were analyzed using a two-way analysis of variance with repeated
measures and Tukey post-hoc test when appropriate. Significance was set at P ≤
0.05. RESULTS: Prolactin (µg●L-1 ): 3-5 RM Pre-Training: Pre-EX-12.5±3.1 Post-Ex
26.8±8.2 Post-Training Pre-Ex 23.2±5.7 Post-EX 64.5±4.5; 20-28 RM Pre-Training:
Pre-EX 8.7±2.3 Post-Ex 27.2±4.5 Post-Training Pre-Ex 11.6±6.3 Post-EX 27.4±9.8:
No Exercise Control Group Pre-Training: Pre-EX 11.7±1.4 Post-Ex 13.3.2±1.3 PostTraining Pre-Ex 14.2±1.7 Post-EX 13.3.4±1.7. Prolactin concentrations significantly
increased after exercise in the exercise groups and the post-exercise values were
significantly greater than control group. The post-training, post-exercise prolactin
concentrations in the higher intensity 3-5RM group was significantly greater than
the low intensity group (20-28 RM). CONCLUSION: Prolactin concentrations in
the blood are susceptible to both exercise stress and high intensities of resistance
exercise with short-term training. The differential response comparing the
heavy to the lighter loading paradigms may well be due to immune and cytokine
interactions due to potentially greater muscle tissue use and damage/repair
phenomenon. PRACTICAL APPLICATIONS: This study verifies that inherent
differences physiologically of heavy and light resistance exercise programs and
can be seen in the early phases of a resistance exercise in men. Poster: 40
RELIABILITY OF THE TURNING POINT CORE TRAINER AS A MEASURE OF PEAK
UPPER TORSO ROTATIONAL VELOCITY, PEAK PELVIC ROTATIONAL VELOCITY,
AND PEAK PELVIC TORSO SEPARATION ANGLE
B. J. AlSarraf1, J. Brown2, M. A. Waller3, P. Eisenman4, C. Hicks-Little5
1
Department of Physical Education and Sport, College of Basic Education in
Kuwait, 2University of Utah, 3Adams State University, 4Department of Exercise
and Sport Science, University of Utah, Salt Lake City, Utah,
5
University of Utah, Salt Lake City, Utah
INTRODUCTION: Pelvic and upper torso rotational velocities are important
contributors to the velocity that is imparted to balls during the volleyball spike,
golf drive, and baseball batting, but the sequencing of pelvic and upper torso
rotation is even more important for imparting high velocity to a ball. Therefore,
being able to readily assess pelvic and upper torso rotational velocities as well as
the sequencing of pelvic and upper torso rotation would be helpful for evaluating
athletes and the efficacy of core strength training programs. The Turning Point
Core Trainer (TP), is a devise designed to quantify axial rotational velocities and
the sequencing of pelvic and upper torso rotation; however, reliability data are yet
to be published. The purpose of the current study was to establish preliminary
evidence for the internal-consistency reliability of the TP as a measure of select
trunk rotational actions (TRA). METHODS: Fourteen Division I female collegiate
volleyball players from the University of Utah volunteered for this study (age
20.9±2.8 years, height 181.6±7.7 cm, weight 72.9±12.5 kg, BMI 22.0±3.0 kg/m2, body
fat 22.0±6.3 %, playing experience 3.2±1.4 years). This study was approved by the
Institutional Review Board at the University of Utah. Each player, after a 10 minute
self-selected warm-up, completed 3 practice trials, and then executed a total of
10 TRA in the TP at zero resistance. A 30 second rest period separated trials. The
TP was used to assess Peak Upper Torso Rotational Velocity (PUTRV) and Peak
Pelvic Rotational Velocity (PPRV) in ˚-sˉ1 for each TRA. The peak difference in the
rotation angle of the pelvis and upper torso about the body’s global x-axis was
recorded in degrees and termed the Peak Pelvic torso Separation Angle (PPTSA). STATISTICAL ANALYSIS: Internal consistency reliability of the TP was assessed
by Cronbach’s alpha Coefficients (α), measurement precision was determined by
coefficient of variation (CV), and standard error of measurement (SEM) was used
to determine between subject variations. The stability was determined by using a
two-way factor mixed (participants random and trials fixed) repeated measures
factorial ANOVA. Statistical significance set at p < 0.05. All data analyzed using
PASW Statistical software18.0 (IBM Inc., Chicago, IL). RESULTS: The results of
statistical analysis are reported in this study. DISCUSSION: The results support the
hypothesis that the TP has excellent internal consistency reliability and support
the use of the TP for assessing rotational variables as part of a sports conditioning
program.
Poster: 41
SHORT-TERM STRENGTH ADAPTATIONS IN YOUNG ADULTS ELICITED BY
MINIMAL AND OVERLOAD RESISTANCE TRAINING INTENSITIES
S. Dorgo1, R. J. Reed-Jones1, N. G. Murray1, P. V. Ambati1
1
University of Texas at El Paso
Previous research showed that morphological changes affect muscular strength
only after six weeks of training and that short-term strength increases are
primarily due to neuromuscular adaptations. It is hypothesized that early strength
increases may be elicited through the practice of resistance training movements
with minimal overload. PURPOSE: To compare the short-term strength changes
between three groups of untrained young adults training with: a) overload
resistance (OR); b) minimal resistance (MR); and 3) no active training (Control).
METHODS: Thirty-nine untrained adults, (mean±SD age: 23.5±3.9; BMI: 25.4±5.2)
with no experience in resistance training were assigned to the OR, MR, or Control
groups using blocked randomization. The experiment focused on two multi-joint
exercises, the bench press and the back squat. Subjects’ strength was assessed
by the one repetition maximum (1RM) tests and by an isometric bench press test
with relevant force plate data collected. Subjects completed two training sessions
weekly with three sets of ten repetitions of each exercise. The OR group used
75% of their latest measured 1RM, while the MR group used a weightless 5 ft.
PVC pipe for both exercises. Subjects in the control group were asked to refrain
from any training during the experiment. Follow-up tests were administered every
two weeks. Strength data were analyzed using a general linear mixed model and
alpha level was set at p<0.05. RESULTS: There were no initial strength differences
between the groups for the 1RM bench press (p>0.9419), 1 RM squat (p=0.9564),
or isometric bench press tests (p=0.06381). From pre- to post-test for the 1RM
bench press the OR group improved 10.2% (p<0.0001), the MR group improved
5.4% (p<0.0001), while the control group showed only minimal (2.4%) and nonsignificant (p=0.0725) improvement. A significant group by time interaction
(p<0.0001) was observed suggesting a different improvement pattern across the
groups. For the 1RM back squat the OR group improved 12.1% (p<0.0001), the MR
group improved 10.3% (p<0.0001), while the control group showed only minimal
(5.2%) but significant (p=0.0415) improvement. A significant group by time
interaction (p= 0.0291) was also observed, confirming the different improvement
patterns across the groups. For the isometric bench press none of the groups
showed significant improvements (p=0.6357). The OR group showed an improving
trend (8.4%) from pre- to post-test, while the MR and Control groups showed
decrements (-4.3% and -0.3%, respectively). Group by time interaction was not
significant (p=0.2388), suggesting a similar response pattern across the groups.
CONCLUSION: According to our results training with overload intensities appears
to be superior even in the initial short time-period of neuromuscular adaptation.
Yet, practicing resistance training movements without any training load appears
to provide sufficient training stimulus to elicit initial strength changes in untrained
subjects. It appears that strength improvement is test-specific, as improvements
in 1RM bench press did not transfer to significant isometric bench press strength
improvement for any group, although the overload resistance group showed a
positive trend. PRACTICAL APPLICATION: Practicing proper exercise technique –
particularly for multi-joint movements – with minimal or no resistance overloads
may provide a safe and effective method of achieving initial strength adaptations
in untrained individuals.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 42
HEAD ACCELERATION WHILE DRIVING A LATE MODEL STOCK CAR
W. Ebben1, E. J. Petushek2, L. Garceau3
1
UW-Parkside, Michigan Technological University, 3Marquette University
2
PURPOSE: Head and neck injuries are among the most common injuries in
stock car racing. Strengthening the affected muscles may help prevent some of
these injuries and help stabilize the head to resist fatigue associated with racing.
The purpose of this investigation was to quantify sagittal and front plane head
acceleration, and determine whether or not these accelerations change over
the course of the race. METHODS: A male stock car driver participated in this
investigation (height=183.0 cm; body weight=88.4 kg; age=46 years). Testing
included a 10 lap heat race on a 0.54 kilometer asphalt race track. Lap times
were competitive and averaged 16.7 seconds, as calculated via video analysis.
A 50 g triaxial accelerometer (BSL, Biopac Systems, Inc., Goleta, CA, USA) was
used to acquire data, which were collected using a multi channel acquisition
system (MP 36R, Biopac Systems, Inc., Goleta, CA, USA) remotely powered using
a manufacturer supplied DC battery pack with data streamed continuously to a
battery powered portable laptop computer. All components were configured
inside a late model stock car (Lefthander Chassis, Rockford, IL, USA). Data were
acquired at 1000 Hz for the entire duration of the race. Data were processed using
low pass filter with a cutoff frequency of 20Hz based on power spectral density
analysis of the frequency content using the Hamming procedure (Acqknowlege 4.1
Biopac Systems, Inc., Goleta, CA, USA). Peak accelerations were analyzed during
race track corner 1 entry, mid corner, and corner 2 exit and were characterized as
units of normal gravitational force whereas 1 g = an acceleration of 9.8 m/s2. Data
were analyzed for the first and ninth lap. RESULTS: Sagittal plane negative
acceleration during corner 1 entry was -0.40 ± 0.08 g’s on lap 1 and - 0.47 ±
0.15 g’s on lap 9, which were not significantly different (P > 0.05). Sagittal plane
positive acceleration during the exit from corner 2 was 0.75 ± 0.03 g’s during lap
1 and 0.83 ± 0.11g’s on lap 9 which were also not significantly different (P > 0.05).
However, mid corner frontal plane lateral acceleration was 1.65 ± 0.03 g’s on lap
1 and 2.16 ± 0.08 g’s on lap 9, representing a significant (P = 0.006) difference. CONCLUSION: Asphalt late model stock car racing produced mid corner lateral
head accelerations as high as 2.16 g’s. This lateral head acceleration increased
23.6% from lap 1 to 9 which may be due to fatigue of neck muscles. PRACTICAL
APPLICATION: Understanding the kinematic demands of stock car racing on the
head and neck may assist the strength and conditioning specialist in prescribing
exercise to strengthen the neck to resist fatigue and potentially some types of
neck injuries.
Poster: 43
THE RELATIVE CONTRIBUTION OF THE RECTUS ABDOMINUS IS
INCREASED IN A MODIFIED SIT-UP COMPARED WITH A TRADITIONAL
SIT-UP DUE TO TRUNK KINEMATICS
F. A. Gardin1, S. Leigh1, C. R. Bellon1, W. Sullivan1
1
Montclair State University
PURPOSE: Core strength is a focus of many training programs and the sit-up is
a cornerstone of many of them. The traditional method of performing a sit-up is
criticized for its use of the hip flexors, and an increased risk of lower back strain.
A modified version of the sit-up may increase the relative contribution of the
abdominals by focusing on trunk flexion over hip flexion. The purpose of this study
was to determine differences in abdominal and hip flexor muscle activation and
trunk kinematics between the traditional sit-up and a modified sit-up. METHODS:
Eighteen males completed two training sessions and then a testing session
consisting of performing two styles of sit-ups: a traditional sit-up according to US
Army regulations, or a modified situp with the instructions “push your lower back
into the floor and pull yourself up with your abdominals”. During testing subjects
completed repetitions of both sit-up styles for 30 seconds each with 10 minutes
rest inbetween. Muscle activation of the rectus abdominis (RA), external oblique
(EO), and rectus femoris (RF) was recorded using electromyography (EMG). Trunk
kinematics were measured using 2-D videography. EMG data were filtered and
normalized. Maximum and mean activation, and integrated EMG (iEMG) were
calculated for one repetition of each sit-up style and over the middle 10-second
time window of each sit-up style. Trunk flexion was calculated as upper trunk
relative to lower trunk. Hip flexion was calculated as lower trunk relative to thigh.
Statistical comparisons were made using a repeated measures design with α =
0.05. RESULTS: Muscle activation and trunk kinematics were significantly different
between sit-up styles. Max and mean activation and iEMG of the RF were greater
during 10 seconds of the traditional sit-up than the modified situp. Max and mean
activation of the RF were greater during one rep of the traditional sit-up than
the modified situp. iEMG of the RF, RA, and EO was greater during the modified
sit-up than the traditional sit-up. The increase in iEMG of the RF from traditional
to midified sit-up was significantly less than the increase in iEMG of the RA and
EO. Peak trunk flexion was greater in the modified sit-up than the traditional situp. Peak hip flexion was greater in the traditional sit-up than the modified situp. CONCLUSION: Our data suggest that RF muscle activation decreases during
a modified sit-up and so the relative contribution of the RA and EO increases.
The workload of the contributing muscles, as measured by iEMG, increased for
all muscles during the modified sit-up when comparing by rep. This increase was
due to an increased time per rep. The RF workload increased less than the RA
and EO workload. These results show the greater emphasis on the abdominals
in the modified sit-up. Our data suggest that the traditional sit-up has a focus on
hip flexion and the modified sit-up has a focus on trunk flexion. Trunk flexion is
associated with a greater contribution from the abdominals, and may decrease
lower back load. PRACTICAL APPLICATION: EMG is a powerful tool to drive
exercise selection. The modified sit-up maybe a better exercise selection when the
goal is to train the abdominal muscles, because it increases the workload of the
abdominal and hip flexor muscles, and increases the relative contribution of the
abdominal muscles. The modified sit-up emphasizes trunk flexion over hip flexion,
which may decrease lower back load and decrease injury risk.
Poster: 44
PATTERNS OF BARBELL ACCELERATION DURING THE SNATCH IN
WEIGHTLIFTING COMPETITION
K. Kipp1, C. Harris2
1
Marquette University, 2LaGrange College
Barbell accelerations during weightlifting exercises have received recent attention
in research studies, primarily because barbell accelerations have been posited as
efficient means to guide and monitor lifting performance during and across training
sessions. Despite this recent attention, however, it is not clear which aspects of
barbell acceleration are most relevant for performance. PURPOSE: To analyze
the patterns of vertical barbell acceleration of the snatch during weightlifting
competition and to determine if and to what extent these patterns are associated
with snatch performance (i.e., lift weight). METHODS: Eighteen lift attempts from
six weightlifters (mean±SD; mass: 97.6±5.5 kg; 1-RM snatch: 97.6±15.5 kg) were
investigated during a regional weightlifting competition. A motion analysis system
was used to track barbell kinematic data, which were used to calculate vertical
barbell acceleration. Time-series data were normalized to 100% of lift phase, which
was defined as the time interval between barbell lift-off and the maximum height
of the barbell during the snatch. The normalized time-series data were pooled
into a single 18 x 101 (lifts x time points) data matrix and entered into a pattern
recognition algorithm. This algorithm was used to extract principal patterns (PP)
and calculate principal pattern scores. Simple linear regressions were used to
determine the correlations between PP scores and lift weight. RESULTS: Lift weight
was significantly correlated with the second extracted PP (r2 = 0.51; p = 0.001),
which captured a difference in peak barbell acceleration between the second
knee bend and 2nd pull phase of the snatch. CONCLUSIONS: Barbell acceleration
patterns are strongly associated with lift weight in the snatch. More specifically,
barbell accelerations of higher weight snatches were steadier, whereas barbell
accelerations of lower weight snatches were characterized by a greater decrease
in accelerations during the second knee bend and greater accelerations during the
second pull. PRACTICAL APPLICATIONS: Higher snatch weights were associated
with smoother barbell acceleration profiles. Unnecessary vertical acceleration may
point to wasted force, which should be transferred into lifting a heavier weight
(i.e., mass) rather than achieving greater barbell acceleration. Weightlifting
coaches should monitor vertical acceleration of the barbell, with special attention
on the steadiness of the acceleration profile.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 45
CHANGES IN WINDMILL PITCH MECHANICS OVER TIME
S. Konz1
1
Marshall University
PURPOSE: Baseball rosters list more pitchers than softball rosters. Baseball pitcher
rotations give pitching staff’s recovery time. Softball teams are not afforded those
options for their pitchers. Softball athletes pitch multiple sessions on consecutive
days or multiple outings within a day. No studies investigated kinematic changes
over a session. The purpose of the study investigated changes in mechanics
occurring through a game. METHODS: 14 female windmill pitchers competing in
the 2009 Big XII Softball Championships in Oklahoma City, OK comprised the pool
for this observational study. IRB waived consent due to public domain. Standard
procedures for 3D motion capture and calibration occurred. Five pitches for each
subject were evaluated. The 5 pitches selected to be digitized were determined by
the total pitch count for each athlete: the 10%, 35%, 60%, 85%, and 100% marks of
total pitches thrown. Digitizing occurred from set position through ball release. A
24-point model represented the softball-glove-pitcher system. The positions of the
throwing arm at 3, 6, 9, 12 o’clock and release were used for comparison. Athletes
were separated into 2 groups by pitch count. The average number of pitches was
41. Group 1 threw more and Group 2 threw less than 41 pitches. Linear regressions
determined the influence of the variables on the independent variable. RESULTS:
An analysis investigated the influence of stride factors on release velocity. The
results explained 55.2% of the variance (R2=.305, F(1,5)=7.26, p<.01). Stride length
(p = .008) was longer and stride angle (p=.011) was wider for athletes in Group1
compared in Group 2. A regression compared the relationship between hip and
shoulder around the z-axis factors on release velocity. The results explained 52.6%
of the variance (R2=.277, F(1,3)=7.28, p<.01). Ball velocity at 12 o’clock (p.=.019)
and shoulder angle in the z-plane (p=.023) were significant in relationship to
release velocity. A regression compared joint angles around the y-axis to the
influence on release velocity. The results explained 77.6% of the variance (R2=.601,
F(1,25)=2.113, p<.021). A final analysis was run focusing on differences between
the two groups at ball release related to previous significant factors. The results
explained 72.4% of the variance (R2=.524, F(1,15)=3.303, p<.01). Shoulder angle at
of the throwing arm (p=.005), hip angle of the stride leg (p=.037), and ankle angle
of the stride leg (p=0.024) were significant between the groups. CONCLUSIONS:
As pitch counts go above 45, windmill athletes lengthen and widen their strides
to maintain velocity production. A longer and wider stride at release provides a
lower release velocity due to a decrease in momentum. An interesting component
related to stride is the impact of stride leg hip FLEX/EXT angle and stride leg ankle
PF/DF angle. A larger angle of the stride ankle and stride hip at 12 o’clock is a not
an optimal contributor to high release velocity. A larger shoulder angle around
the z-axis at release is not optimal for release velocity. However, greater shoulder
angle at 12 o’clock contributes to higher release velocity. The velocity of the ball
at 12 o’clock affects the overall release velocity. PRACTICAL APPLICATIONS:
Protocols to address muscle strength of the upper extremity at 12 o’clock would
be helpful. Limiting appearances or lower pitch counts help to preserve athlete
health.
Poster: 46
ACUTE AND ACCUMULATED FATIGUE MEASURED BY
STRETCH-SHORTENING CYCLE FUNCTION IN YOUTH RUGBY UNION PLAYERS
DURING A 7-WEEK COMPETITION CYCLE
R. S. Lloyd1, J. Oliver1, A. Whitney1, M. De Ste Croix2
1
Cardiff Metropolitan University, 2University of Gloucestershire
PURPOSE: Rugby union involves high intensity intermittent exercise, which is
known to induce neuromuscular fatigue. Exhaustive high-intensity exercise is
specifically known to negatively affect stretch-shortening cycle (SSC) function, in
particular stiffness properties of the lower limbs [1]. Fast and slow expressions of
SSC can be measured via countermovement jumps (CMJ), reactive strength index
(RSI) and leg stiffness respectively [2]. Despite existing research highlighting the
fatiguing effects of competitive rugby league match play on CMJ performance
[3], little is known about the acute and accumulated fatigue of rugby union match
play on either RSI and leg stiffness, especially in youth players. METHODS: Eleven
male youth rugby union players (age: 16.9 ± 0.8 y, body mass: 86.8 ± 10.5 kg,
stature: 176.3 ± 4.6 cm) volunteered to participate in the study. SSC function was
measured using a mobile contact mat, and variables determined included jump
height (during a CMJ), RSI (during maximal hopping) and leg stiffness (during
sub-maximal hopping). Participants completed two trials of the CMJ and maximal
hopping, with the best trial being used for analysis, and a single trial of the submaximal hopping test. Baseline data was collected a week prior to the start of the
7-week competition block. Subsequent data collection was obtained pre-match
and 1-day post-match during weeks 1, 4 and 7 of the competition block. RESULTS:
Players completed an average of 600 ± 150 mins of training or competition a week
during the 7-week competitive cycle. Acute changes in CMJ height, RSI and leg
stiffness were generally able to demonstrate significant reductions in performance
from pre- to post-match (P < 0.05). Accumulated fatigue was observed via
significant reductions in pre-match CMJ height in weeks 4 and 7, and before week
7 for leg stiffness compared to baseline (P < 0.05). While accumulated fatigue
experienced by week 7 was associated with further acute post-match reductions
in CMJ height, leg stiffness failed to show further acute changes. CONCLUSION:
Data indicate that all measures of SSC function were able to determine acute
neuromuscular fatigue following competitive match play. CMJ height consistently
showed the greatest performance decrement pre- to post-match and might be
the most suitable test to measure acute fatigue. Both CMJ height and leg stiffness
showed evidence of accumulated fatigue across the competition block, however,
the accumulated fatigue led to different acute post-match responses between
the two measures by week 7. PRACTICAL APPLICATIONS: For the long-term
monitoring of neuromuscular fatigue in youth rugby union players, it is imperative
that an accurate baseline measurement, which reflects a well-rested state, is
obtained. It is recommended that within a competitive cycle, coaches should
consider monitoring both slow and fast indices of SSC via regular measurements
of CMJ height and leg stiffness. This is because while both measures are sensitive
to detecting acute and accumulated fatigue, the acute responses become
movement-specific where fatigue has accumulated. REFERENCES: [1] Kuitunen et
al. Scand J Med Sci Sports 17: 67-75, 2007. [2] Lloyd et al. J Sports Med Phys Fitness
51: 595-602, 2011. [3] McLellan et al. J Strength Cond Res 25: 1030-1039, 2011.
Poster: 47
THE RELATIONSHIPS AMONG THE SLOPES OF THE MECHANOMYOGRAPHIC
AMPLITUDE-FORCE PATTERNS OF RESPONSE AND THE FATIGUE INDEX FOR
THE LEG EXTENSORS
M. Cooper1, T. J. Herda2
1
University of Kansas, 2University of Kansas /
Biomechanics Laboratory, Lawrence, KS
*Award Eligible - Outstanding Master’s Student Poster Presentation
Purpose: The purpose of this study was to examine the slopes from the
mechanomyographic amplitude (MMGRMS) vs. force relationships for the vastus
lateralis (VL) and rectus femoris (RF) and correlations between the slopes from
these relationships and the fatigue index from 50 maximal concentric isokinetic
muscle actions of the leg extensors. METHODS: Forty healthy subjects (females, n
= 23; age, 20.5 ± 1.7 years; height, 1.69 ± 0.06 m; weight, 67.3 ± 8.9 kg; males, n =
17; age, 21.2 ± 3.0 years; height, 1.80 ± .08 m; weight, 81.9 ± 13.6 kg) volunteered to
perform isometric ramp contractions of the leg extensors from 10% to 85% of their
maximal voluntary contraction (MVC). MMG (m∙s-2) signals were recorded from
the VL and RF muscles. Simple linear regression models were fit to the natural
log-transformed MMGRMS vs. force relationships. The slope (b term) was calculated
for each relationship. Subjects also performed 50 repeated maximal concentric
isokinetic muscle actions at 180°/s. The individuals fatigue index was calculated
as [(Initial Peak Torque – Final Peak Torque)/Initial Peak Torque]*100. Pearson’s
product moment correlations (r) were calculated among the fatigue indexes,
MMG RF b terms, and MMG VL b terms. Multiple regression was also performed
to determine if the b terms from the MMG VL and RF could be used to predict
the fatigue index. The alpha level was set at ≤0.05. RESULTS: The b terms from
the MMGRMS vs. force relationships for the VL (r = 0.417) and RF (r = 0.386) were
both significantly correlated (P=0.01, P=0.05) to the fatigue index, however, the
correlations would be considered small. In addition the b terms from the VL and
RF were correlated (P=0.01) with each other (r = 0.688). Multiple linear regression
indicated that the b terms from the VL and RF only accounted for 19% of the
variance in the fatigue index. Conclusions: Previous research has demonstrated
that the fatigue index is related to muscle fiber type composition and the b terms
have also been reported to be influenced by muscle fiber type composition. The
higher b terms indicate a later onset of rate coding as a primary mechanism of
increasing force, which has indicated that the muscle has a larger percentage of
type II fiber. We would therefore expect higher b terms to be correlated with higher
fatigue indexes due to the high fatiguability of type II fiber. Although there were
significant relationships between the fatigue index and slopes from the MMGRMS
vs. force relationships for the VL and RF in the present study, the correlations
would be considered small. In addition, the slopes from these relationships only
accounted for 19% of the total variance in the fatigue index. Practical Applications:
The log-transformed MMGRMS model was unable to account for a large enough
percentage of the variance in the fatigue index to be considered an acceptable
method for the prediction of leg extensor fatigability. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 48
CAN MUSCULOTENDINOUS STIFFNESS OF THE POSTERIOR MUSCLES OF
THE HIP AND THIGH PREDICT MUSCLE POWER OUTPUT IN FEMALE
ATHLETES AND SIZE-MATCHED CONTROLS?
T. B. Palmer1, M. J. Hawkey1, D. B. Smith1, E. C. Conchola1, B. M. Adams1,
K. Akehi1, R. M. Thiele1, B. J. Thompson1
1
Oklahoma State University
Musculotendinous stiffness (MTS) measures the passive mechanical properties of
a muscle-tendon unit and is expressed as the slope (Nm·°-1) of the curvilinear
relationship between passive torque (Nm) and joint angle (°) displacement.
Greater MTS has been associated with improvements in rate of force development
and consequently, may be an effective predictor of muscle power output during
high explosive-type movements (i.e., vertical jump). PURPOSE: To examine the
efficacy of MTS of the posterior muscles of the hip and thigh to predict muscle
power output in female athletes and size-matched controls. METHODS: Ten
highly-trained NCAA Division I female soccer athletes (mean±SD, age=19±1yr;
mass=65±7kg; and height=166±5cm) and eleven recreationally-trained sizematched controls (age=20±2yr; mass=63±9kg; and height=162±7cm) performed
three countermovement vertical jumps (CMJ) followed by two passive straightleg raise (SLR) assessments using an isokinetic dynamometer programmed
in passive mode to move the foot toward the head at 5°·s-1. CMJ height and
estimated peak power output (Pmax) were measured during the CMJs using a jump
mat and linear velocity transducer. For each SLR, participants lied in a supine
position with the knee- and ankle-joints immobilized with custom-built stabilizing
apparatuses. All assessments were performed on the right leg, while the left thigh
and ankle were secured with restraining straps. Bipolar surface electromyographic
(EMG) amplitude of the biceps femoris was sampled during each SLR. MTS was
calculated during each SLR as the slopes of the initial linear portion (phase 1)
as well as the second steeper portion (phase 2) of the angle-torque curve.
RESULTS: There were no differences between groups for age, height, and mass
(P>0.05). The athletes exhibited greater MTS, CMJ height, and Pmax than the
controls (P=0.004-0.036). There were no group-related differences for range of
motion (ROM) or EMG amplitude (P>0.05). MTS increased from phase 1 to phase
2 (P<0.001); however, EMG remained unchanged across the ROM (P>0.05). There
were significant positive relationships observed between MTS of both phases
and CMJ height and Pmax (r=0.483-0.827; P≤0.001-0.027). CONCLUSIONS: These
results suggest that during the passive SLR assessments, MTS was greater for the
athletes than controls despite no differences between groups for anthropometric
measurements, EMG amplitude, or ROM. In addition, the athletes demonstrated
higher Pmax and CMJ height than the controls, which also significantly correlated
with MTS at phases 1 and 2. PRACTICAL APPLICATIONS: MTS of the posterior
muscles of the hip and thigh is an effective predictor of muscle power output in
NCAA Division I female athletes and size-matched controls. MTS may serve as an
additional performance measure to help coaches recruit and identify powerful
female athletes and provide support for the utility of this laboratory measure to
translate to “on the field performance.”
Poster: 49
INTER-TESTER RELIABILITY OF THE FUNCTIONAL MOVEMENT SCREEN ACROSS
DISCIPLINES
E. P. Scibek1, S. Edmond2, M. F. Moran3
1
Sacred Heart University, 2University of Medicine and
Dentistry of New Jersey, 3Sacred Heart University
PURPOSE: The Functional Movement Screen (FMS) is a widely used battery of
tests developed to assess the quality of fundamental movement patterns by
movement science professionals. Previous studies have established the intertester reliability of the FMS for different levels of experience and within disciplines,
but none have examined inter-tester reliability across disciplines. The purpose
of this study was to examine the inter-tester reliability of the FMS across the
three movement science disciplines: athletic training (AT), physical therapy (PT)
and exercise science (EX). METHODS: Three testers, one from each discipline,
evaluated 28, NCAA Division I male athletes. Each athlete performed the seven
tests of the FMS, which includes the Deep Squat (DS), Hurdle Step (HS), In-Line
Lunge (IL), Active Straight Leg Raise (ASLR), Trunk Stability Push-Up (PU), Rotary
Stability (RS), and Shoulder Mobility (SM) tests along with clearing tests for the
PU, RS, and SM tests. Frontal plane and sagittal plane video was assessed by each
of the three testers. To determine inter-tester reliability, Intraclass Correlation
Coefficients (ICC) were calculated across all 3 testers as well as between the
disciplines for each of the 7 tests of the FMS and the overall FMS scores. The
scores were considered good if ICC>0.75, moderate if ICC = 0.5-0.75 and poor if
ICC<0.5. RESULTS: When the data from all three testers were combined there was
at least moderate reliability on 4 of the 7 tests as well as the overall FMS score,
with SM (ICC = .917) scoring the highest and HS (ICC = .283) the lowest. The SM
test was the only test that had good reliability with the HS, IL, and PU having
poor reliability. The reliability between the AT/EX testers was the most consistent,
with all tests resulting in at least moderate reliability and the overall FMS score,
DS, ASLR, PU, and SM tests having good reliability. For the AT/PT group and the
PT/EX group inter-tester reliability was moderate for the overall FMS score, RS,
and ASLR scores and good for the SM scores. Reliability for the DS was moderate
within the PT/EX group, but the remaining measures were poor within the two
groups. The SM test had the highest inter-tester reliability among all groups; AT/
EX (ICC = .954), AT/PT (ICC = .934) and PT/EX (ICC = .905). The IL test had
the lowest inter-tester reliability for the AT/EX group (ICC = .600) and the AT/PT
group (ICC = .308) while the PU test resulted in the lowest inter-tester reliability
for the PT/EX group (ICC = .263). CONCLUSION: The results indicate that there is
variation in the interpretation of movement patterns and in the scoring of some
measures of the FMS across movement science disciplines. These differences may
be the result of education and training as well as clinical experience within the
tester’s field of practice. PRACTICAL APPLICATION: Tester discipline within the
movement sciences should be considered when comparing FMS scores between
testers.
Poster: 50
MALES AND FEMALES PERFORM DIFFERENTLY ON MEASUREMENTS
RELATED TO CORE STABILITY
A. Waldhelm1, L. Li2
1
University of the Incarnate Word, 2Georgia Southern University
PURPOSE: Enhancing core stability has become a popular training intervention for
athletes of all sports. Unfortunately, a universally accepted method to assess core
stability has not been developed. It is widely accepted that several measurements
must be used to thoroughly assess core stability. Through a thorough literature
search we have found 3 clinical assessments and 35 tests which have been used for
core stability related testing. Most researchers have used a subset of these outcome
variables. Furthermore, it is unknown whether gender differences in core stability
exist. Therefore, the purpose of our study was to determine gender differences
when performing three clinical assessments associated with core stability and 35
tests related to five individual components of core stability. METHODS: Participants
included 18 college-aged males and females who had not suffered an orthopedic
injury in the past year. The participants provided informed consent as approved
by the Institutional Review Board, prior to testing. The three clinical assessments
consisted of the Star Excursion Test and the Frontal Plane Projection Angle of the
knee during a single leg squat and drop. The 35 specific core stability related tests
were grouped into five categories: strength, muscular endurance, flexibility, motor
control, and function. To determine gender differences, one-tailed independent
t-tests were used for each clinical assessments and tests related to core stability.
RESULTS: No significant gender differences were identified with all three clinical
assessments. After adjusting for body weight, males were significantly stronger
in the isometric strength tests for trunk flexion, t(34) = 2.24, p = .02, dominate
hip extension, t(34) = 1.91, p = .03, and dominate, t(34) = 2.73, p < .01, and nondominate, t(34) = 3.99, p < .01, hip abduction. Significant strength differences for
trunk extension, non-dominate hip extension, and bilateral hip external rotation
were not noted. Also, males performed significantly better in a one minute sit
up test, t(34) = 3.85, p < .01. Males had significantly longer hold times for two
of the four muscular endurance tests, right, t(34) = 2.73, p < .01, and left, t(34)
= 1.98, p = .03, side plank tests. Differences were not observed for the trunk
flexion or trunk extension endurance tests. There were no significant differences
identified with all 11 flexibility tests. The results of the motor control tests revealed
females exhibited significantly better single limb balance with, t(34) = 2.52,
p < .01, and without vision, t(34) = 4.27, p < .01. For the functional tests, males
performed significantly better in a thirty second squat test, t(34) = 2.06, p = .02
and the hop tests for speed, t(34) = -4.93, p < .01, and distance, t(34) = 3.78, p
< .01. CONCLUSIONS: Males performed better on measurements assessing core
strength, muscular endurance and function, while females demonstrated better
motor control. No differences were observed for the clinical assessments and the
flexibility tests. PRACTICAL APPLICATIONS: Current clinical assessments may not
be sensitive enough to test differences in core stability between college-aged
male and female. Further, college-aged males and females perform differently on
tests which evaluate individual components related to core stability. These results
indicate males and females may require different core stability training regiments
to offset specific core stability impairments.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 51
CROSS-VALDIATION OF A 3D MARKERLESS MOTION CAPTURE SYSTEM
AGAINST VIDEO AND A 3D MARKER MOTION CAPTURE SYSTEM
D. Wassom1, A. C. Fry2, N. Moodie3
Dynamic Athletics, 2The University of Kansas,
Human Performance Laboratory, Lawrence, KS, 3Rockhurst University
production is a goal, it would be more advantageous to exercise the infraspinatus
in a neutral position than in a position of scaption and to utilize manual resistance. Monitoring infraspinatus thickness with USI is not supported as a measurement of
increased force production.
Poster: 53
1
PURPOSE: The purpose of the study was to compare the knee angle calculated
from 3 different collections methods and evaluate the validity of 3D Markerless
motion capture. METHODS: One male participant was used for data collection. The subject did 15 controlled squats in both a 3D marker and markerless motion
capture collection space. These collections were separated due to the fact
the environments are incompatible for simultaneous use. Furthermore, during
another testing session 15 separate squats were collected simultaneously with 3D
markerless capture and video. Only the left legs of the videoed squats were used
for data analysis between 3D Markerless motion capture and video. To control the
movement protocol a standardized box was used to control depth of the squat
and well as standardized distances to the box and distance between feet. The
software specifically identified the peak joint angle of the squat as the indicator
of when values were measured. The subject paused at the bottom of the squat
before rising to allow for proper time for video to be taken. RESULTS: The analysis
showed there is no significant difference between the 3D markerless system and
the marker based system for the right [t(15)=.1720, p>0.05] or left [t(15)=.0801,
p>0.05] (knee) angles. The mean angles and standard deviation values for 3D
Markerless system being (R- 93.56°; +/-.86)( L- 93.37°;+/- 1.46) and the marker
motion capture system were (R- 92.95°;+/- 1.45)(L- 94.34°;+/- 1.48). There is
also no significant difference between the right leg of the markerless system and
the photos [t(15)=0.1017, p>0.05]. The mean angle values for the 3D markerless
sytem and photos respectfully were (R- 86.54°; R- 85.84°). CONCLUSIONS: The
results of the present study indicate that angles can be successfully measured
by the 3D markerless motion capture system. Further research should be done
to validate other joints. PRACTICAL APPLICATION: The use of a 3D Markerless
motion system may be beneficial in reducing set up time for an individual and
tester, thus increasing the ability to volumize collections.
Poster: 52
THE EFFECT OF SHOULDER POSITION ON THE THICKNESS AND FORCE
PRODUCTION OF THE INFRASPINATUS
D. Witt1, N. Talbott1, S. Belen1, E. Thompson1
1
University of Cincinnati
Purpose: Activity of the infraspinatus is critical for proper shoulder mechanics
during the many shoulder movements performed by throwers, swimmers, tennis
players and other athletes. When injured, the infraspinatus must be assessed and
appropriate exercises initiated. Two commonly utilized positions and movements
for these assessments and exercises are 1) resistance of external rotation with the
arm in a neutral position; and 2) resistance of external rotation with the arm in
elevated to ninety degrees in the plane of the scapula (scaption). The purpose
of this study is to determine if the infraspinatus force production and thickness
significantly change when the shoulder is moved from a neutral position to a
position of ninety degrees of scaption. Methods: Ten shoulders from five healthy
subjects were tested using ultrasound imaging (USI). With the subject sitting,
the shoulder was placed in a neutral position and the mid-third of the spine of
the scapula. Measurements were repeated as the subject performed a maximal
isometric external rotation contraction against a stable dynamometer and,
after resting, a maximal isometric external rotation contraction against manual
resistance applied through a hand held dynamometer. Force was recorded during
each contraction and a corresponding ultrasound image stored. The process was
repeated with the shoulder in a position of 90 degrees of elevation in the scapular
plane. All measurements and images were taken three times. Ultrasound images
were analyzed off line with linear measurements of the infraspinatus recorded
for each contraction. Results: The isometric force when pushing against a stable
dynamometer significantly varied between positions decreasing from 19.9lbs
when the shoulder was in a neutral position to 13.1lbs when the shoulder was in 90
degrees of scaption. A similar pattern was noted when pushing against manual
resistance with force production decreasing from 27.9lbs in a neutral position to
19.4lbs in the scaption position. Although linear thickness of the infraspinatus did
increase approximately 30% from the rest to the resisted conditions, no significant
differences were found in the thickness in the different positions. Conclusions:
Force exerted by the infraspinatus was greater in a neutral position when manual
resistance was applied. Changes in infraspinatus thickness, as measured by
USI, did not significantly change between the rest and the resisted conditions,
regardless of shoulder position Practical Applications: If maximal force
COMPARISON OF PERCENT BODY FAT AS DETERMINED BY AIR DISPLACEMENT
PLETHYSMOGRAPHY AND TWO BODY ADIPOSITY INDEX EQUATIONS
J. Brown1, A. Tran1, K. Ouellette1, L. Young1, H. Johnson1, R. Cotter1, B. Trepp2, J.
LaReaux1, M. A. Waller3
1
University of Utah, 2PEAK Health and Fitness/University of Utah,
3
Adams State University
The ability to measure body composition accurately is important for health, fitness,
and sports performance. The use of less accurate anthropometric tools may lead
to misclassification of health risk. The Body Adiposity Index (BAI) was recently
introduced as a method of predicting body composition using hip circumference
and height. Research has demonstrated a stronger correlation between BAI and
body fat, than between body mass index (BMI) and percent body fat (PBF) in
Mexican-American and African-American Adults. A variation of the BAI formula
from the FELS longitudinal study (BAIFELS) has more recently been proposed
as a better predictor of body fat than BAI. PURPOSE: To examine the difference
in body fat percentage using Air Displacement Plethysmography (Bod Pod) and
two BAI equations. We also sought to examine the level of agreement among the
various methods used to estimate body fat percentage. METHODS: 366 healthy
adults (194 = males; 172 = females; age = 37.27 ± 9.94 years; height = 1.73 ± 0.10
m; body mass = 77.12 ± 18.73 kg; body fat = 24.51 ± 8.50 %; waist circumference
= 84.6 ± 13.5 cm; hip circumference = 99.2 ± 9.4 cm; and BMI = 25.39 ± 4.52 kg/
m2) volunteered for data analysis. Air displacement plethysmography was used
to assess PBF. Prior to measurement the Bod Pod was calibrated according to
manufacturer’s specifications and participants were asked to void the bladder
and change into skin tight clothing. A wall-mounted stadiometer was used to
measure height and an anthropometric measuring tape was used to measure hip
circumference to the nearest 0.1 cm. Body mass was measured to the nearest 0.01
kg using an electronic scale attached to the Bod Pod. A prediction equation was
used to assess thoracic gas volume. PBF was predicted using BAI according to the
following equation: BAI = [hip circumference/height1.5] – 18. PBF was predicted
for BAIFELS using the following equation: BAIFELS = 1.26*[hip circumference/
height1.4] – 32.85. RESULTS: PBF for Bod Pod, BAI, and BAIFELS was 24.51 ±
8.49, 25.57 ± 4.49, and 25.13 ± 5.80%. Repeated Measures ANOVA found a
significant difference in body fat percentage between methods. Bonferroni posthoc analysis revealed BAI to be significantly lower than Bod Pod and BAIFELS.
Significant correlations were greater between BAIFELS and Bod Pod (r= 0.71, p
< 0.01) and BAI and Bod Pod (r = 0.72, p < 0.01) than between BMI and Bod Pod
(r = 0.54, p < 0.01) respectively. Visual inspection of the plots revealed smaller
mean differences for BAIFELS than BAI and BMI, large limits of agreement, and
numerous points outside those limits for all comparisons. CONCLUSION: These
results show BAI significantly underestimates PBF compared to BAIFELS and the
Bod Pod. Furthermore, Bland-Altman plots suggest poor agreement between
BAI prediction equations and the Bod Pod. PRACTICAL APPLICATIONS: The
results from this study suggest the BAIFELS is a better predictor of PBF than BAI.
However, due to the large limits of agreement fitness professionals should utilize
additional assessments such as waist circumference and BMI when categorizing
health risk. ACKNOWLEDGEMENTS: This study was supported by PEAK Health
and Fitness, University of Utah.
Poster: 54
THE INDICES OF BONE IN RESPONSE TO EXERCISE
K. J. Heumann1, B. Warr2, P. Swan3, B. Alvar4
1
Colorado Mesa University, 2Military Performance Division, U.S. Army Research
Institute of Environmental Medicine, 3Arizona State University, Exercise and
Wellness, 4Rocky Mountain University of Health Professionals
PURPOSE: It is widely accepted that weight bearing physical activity is beneficial
for bone health. The gold standard for bone measurement is DXA (dual energy
X-ray absorptiometry). To observe changes in bone by DXA, a minimum of a
4-month intervention is required. Serum osteocalcin (OC) (a bone formation
marker) and quantitative ultrasound (QUS) of the calcaneus may be useful as
short term indicators of bone change but the sensitivity of these indices to
short term interventions are unknown. The purpose of this study was twofold: to
compare monthly changes in OC and QUS in response to jumping exercise and to
evaluate the relationship between DXA, OC and QUS. METHODS: Young women
with calcaneal bone t-scores less than 1.0 were randomized into a jump training
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
(J) (n=16) or control (C) group (n=16). J consisted of a progressive routine of 1
and 2-footed jumping performed 3 days/week for 4 months. Body composition,
QUS and OC were measured at baseline, and monthly for 4 months. DXA and
24-hour dietary recalls were completed at baseline and 4 months. A total of 26
women were included in final analyses. RESULTS: No significant differences were
observed between groups at baseline in body composition or bone variables.
Monthly increases were observed in OC in both groups but there were no
significant differences between groups in any bone variables from baseline to
4 months. No significant relationships between DXA, QUS or OC existed. Upon
further analysis, when the population was separated by median split into highand low-physical activity based on weekly self-report, there were significant
increases in OC in the high active group as compared to the low active group.
CONCLUSION: Neither DXA, OC or QUS were specifically sensitive to the jumping
intervention in this population of women. PRACTICAL APPLICATION: While no
technique was sensitive enough to detect acute changes in bone in response
to jumping in healthy young women, compared to DXA and QUS, OC may be
a better marker of bone changes in response to overall physical activity level.
ACKNOWLEDGEMENTS: This research was funded by the Graduate Professional
Student Association at Arizona State University and the Charles Corbin Research
Fellowship.
Poster: 56
THE IMPACT OF ACADEMIC STRESS ON CHANGES IN
STRENGTH, CIRCUMFERENCE, AND BODY MASS DURING A 16 WEEK
STRENGTH TRAINING COURSE.
D. Hollander1, B. Sirikul1, B. Williams1, B. Henry1, H. Rop1, E. Brown1,
M. Todesco1, A. Hargett1, A. Luwe1, D. Smith1,
A. Fritscher1, S. Martin1, E. Turner1
1
Southeastern Louisiana University
PURPOSE: To assess the impact of academic stress on strength and body
composition changes across 16 weeks in a college sample rating different stress
levels. An initial study demonstrated that across 16 weeks, undergraduates rating
low in negative stressful life events gained more strength (i.e., bench press and leg
press pre-post) as compared to their higher stressed counterparts (Bartholomew
et al., 2008) This compelling finding would suggest that homeostasis may be
compromised due to chronic stimulation of the HPA (hypothalamic-pituitaryadrenocortical) axis. Ergo, alterations in morphology as well as strength could
be impacted by perceived stress or allostatic load. METHODS: Sixty one subjects
(21.44±5.25 yrs, 1.7±.24 m, 76.3±23.0 kg) (38 men, 22 women)were assessed prior
to and at the end of a 16-wk moderate intensity resistance exercise program.
Stress surveys (visual analogue), body composition (3 site-skinfold), stress
surveys (visual analogue) of academic, relationship, monetary, and overall stress, 5
circumference sites; arm, chest, waist, hips, and thigh, and 3-8 multiple-repetition
maximum lifts (bench and leg press) were all collected pre and post 16 weeks. An
overall MANOVA did not find significant differences between men and women
across the stress and physical measures. However, heterogeneity of variance
was determined suggesting a bimodal distribution thus subsequent analyses
employed non-parametric assessments. Individuals were then categorized as
high, medium, and low academic stress and then reassessed based on reported
academic stress level. No significant differences were observed for changes in
strength. However, a mean comparison revealed a significant difference for
leg press strength change, t=1.99, p <0.05. Specifically, high academic stress
demonstrated lower strength increases for leg press (73.5±26.36 lbs versus
148.18±24.18 lbs) compared to their lowest stress counterparts. The circumference
measures when compared across the academic stress category revealed that only
thigh circumferences were significantly different between groups, X2= 7.3, p < 0.05.
Specifically, high stress individuals had greater reduction in thigh circumference
(1.65 inch decrease) as compared to their lower stressed counterparts (0.13 inch
increase and .06 inch decrease). Significant differences were determined for
academic stress (F=5.08, p=0.009), such that individuals in the high stress group
gained 2.65% body fat, while the medium and low academic stress groups lost
1.13% and 0.91% respectively. CONCLUSION: The findings suggest that high stress
negatively strength of the lower body for our sample across 16 weeks. Only thigh
circumferences were altered as well when comparing stress ratings. It is possible
that activation of the HPA axis, behavioral anomalies, or lifestyle changes impacted
these trends. PRACTICAL APPLICATION: Future studies could measure hormonal
and behavioral variables to delimit influence of patterns related to adaptation
to resistance exercise. By monitoring the acute changes in stress (mental and
physical) during training cycles, strength coaches can work to avoid / explain
unwanted changes in body composition and minimal strength gains related to the
allostatic load experienced by their athletes. Poster: 57
ANTHROPOMETRIC DIFFERENCES AMONG NCAA DIVISION I ATHLETES BY
TRAINING BIAS AND MEASUREMENT TYPE
T. Keating1, B. Carroll1, V. Santos1
1
Manhattan College
Currently, no universally accepted standards of body composition assessment exist
for athletes. Due to differences in the various body composition compartments,
certain anthropometric measures may be better suited for certain athletic
populations. PURPOSE: The purpose of this investigation was, therefore, to
examine differences in a variety of anthropomentric measures between Division
I athletes and controls. METHODS: Subjects included 19 Division I athletes (11
male, 8 female, 20+1 yrs) and 9 controls con (5 male, 4 female, age 22+1.2 yrs)
Upon data collection, the decision was made to further stratify athletes into the
following categories by training volume bias: Aerobic AER (5 male, 4 female) and
Anaerobic ANA (6 male, 4 female). Subjects reported to the Exercise Physiology
Laboratory in the afternoon, prior to physical activity and at least 2 h postprandial
during the same 2 week period. The following measures were assessed: height,
weight, BMI, percent fat from skinfolds SF (Jackson Pollock 3 site) and percent
fat from bioelectrical impedance analysis BIA (Omron HBF 306). The same skilled
technician performed all SF measures. Data were analyzed using a One-way
ANOVA and a paired samples t test. RESULTS: Surprisingly, no differences were
found among groups for either BMI (AER 24.2+2.7, ANA 24.2+1.8, CON 25.1+1.8)
or percent fat from either method (SF AER 14.9+4.8, ANA 14.2+8.7, CON 13.7+8.2
%fat; BIA AER 16.2+5.1, ANA 16.6+6.2, CON 17.8+7.4 %fat; p>.05). Paired samples
correlations revealed strong agreement (r=.91, p<.05) between SF and BIA on the
whole, though BIA predicted higher (14.2+6.6 vs. 16.2+5.3 %fat). Of note, 37% of
athletes and 50% of CON classified as overweight, while falling well within the
normal range of %fat. CONCLUSIONS: It can be concluded that either BIA or
SF are acceptable techniques for the assessment of body composition in college
athletes. BMI, on the other hand does not provide useful body composition data
in samples of non-obese college students.
Poster: 58
BODY COMPOSITION ANALYSIS OF AIR FORCE MEN AND WOMEN
G. Leahy1, T. Crowder2, J. L. Mayhew3, A. E. Smith-Ryan4
Davis-Monthan Air Force Base, 2United States Military Academy,
Truman State University, 4University of North Carolina Chapel Hill
1
3
There is widespread concern among varying branches of the military regarding
an accurate measurement of body composition, since it is considered a major
factor in fitness performance tests. Various measurement techniques have been
employed by the different branches with limited support of a universal approach. PURPOSE: To evaluate body composition, as measured by fat mass (FM), fat-free
mass (FFM) and percent body fat (%fat), in comparison to body mass index (BMI),
of active duty Air Force personnel. METHODS: Air Force men (n = 604) and
women (n = 343) were evaluated for body composition using air displacement
plethysmography (BodPod®, Life Measurement). Individuals were stratified by
age, determined by decade; with individuals <20 yrs (n = 13) combined with the
20-29 yr-old group. Height and weight were used to calculate BMI = kg/m2. BMI groups were determined using the standard categories (Underweight ≤18.5,
Normal = 18.6 to 24.9, Overweight = 25.0 to 29.9, Obese ≥30). Masked obesity
was assessed as BMI<25 when %fat was greater than the obesity level for men
(≥20%) and women (≥30%). RESULTS: A 2 × 4 (Sex × Age Group) MANOVA
produced a significant interaction effect (p=0.001) for % fat, FM, and weight, but
not FFM. Analysis of %fat and FFM indicated increasing %fat in both sexes until
≥50 yrs for men and decreasing FFM in both sexes until ≥50 yrs for men. %fat
was positively related to age in both men (r = 0.16, p<0.001) and women (r =
0.25, p<0.001), with no significant difference between the correlation coefficients
(p = 0.35). The slope of the regression line for age on %fat was significantly
greater for women than for men, indicating that women gain on average 0.20
% fat/yr while men gain 0.15 % fat/yr. Fat mass (FM) was positively correlated
with age in both men (r = 0.15, p<0.001) and women (r = 0.16, p<0.003), with
similar regression slopes of 0.16 kg/yr and 0.18 kg/yr, respectively. Fat-free mass
had a small but significant negative correlation with age in women (r = -0.11, p =
0.05), but a nonsignificant correlation in men (r = -0.04, p = 0.28). Age was not
significantly related to weight gain in either men (r = 0.08, p = 0.06) or women (r
= 0.07, p = 0.18). Masked obesity was noted in 7% of men and 19% of women. In
obese military subjects (classified by %fat), 10% of men and 30% of women had
masked obesity. High BMI values correctly identified 59% of obese men (>20%
fat) and 44% of obese women (>30% fat). Only 6 men and no women had BMI
values ≥30 kg/m2 when %fat was less than the obesity cutoff. CONCLUSION: Air
Force personnel tend to gain FM and lose FFM across the age span from 20 to 50
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
yrs. This produces an average increase in %fat of approximately 3.5% for men per
decade until 50 yrs, followed by a decrease. In women, the increase per decade
is approximately 2.5% fat across all ages. BMI may not be sufficient for tracking
changes in body composition for either sex. PRACTICAL APPLICATION: Simple
yet practical alternate methods of tracking body composition changes in military
personnel should be explored to increase sensitivity, as well as more accurately
determine health cut-off categorizations. Poster: 60
PRESEASON AND POSTSEASON BODY COMPOSITION DOES NOT CHANGE
RELATIVE TO PLAYING TIME IN DIVISION I FEMALE BASKETBALL PLAYERS
A. L. Shim1, E. Ladwig1, J. Yom1, P. Cross1, J. Beebe1
1
The University of South Dakota
PURPOSE: Body composition has gained a great deal of recognition in a range
of sports with regards to optimal physical performance. As the level of body fat
increases, work capacity diminishes. The excess fat serves as deadweight and
does not assist the delivery of oxygen to muscles during exercise. The importance
of maintaining a low body fat is particularly stressed in high intensity sports such
as basketball, in which the metabolic demands are especially high. The purpose
of this study was to determine if preseason and postseason body fat percentages
(BF%) change relative to playing time in Division I women’s basketball players.
METHODS: Subjects for the study included 11 National Collegiate Athletic
Association (NCAA) Division I female collegiate basketball athletes over the age
of 18 from a Midwest public university. The subjects underwent preseason and
postseason air displacement plethysmographytesting to get an accurate measure
of body fat percentages. RESULTS: Data analyses looked for changes between
preseason and postseason body fat percentage. A Pearson’s Correlation was
performed to determine if changes in preseason and postseason BF% changed
relative to playing time. Body fat percentage varied across preseason and
postseason (average decrease in BF%: -1.83%) but such a difference was not
significant (t1,10 = 1.89, p = .088). A significant relationship was found between
preseason BF% and playing time (r = -.707) and postseason BF% and playing time
(r =-.728). CONCLUSION: No relationship was found between change in BF% and
playing time. PRACTICAL APPLICATIONS: Body fat tracking should be utilized
preseason, in season, and postseason to gauge on the nutritional and physical
performance level of female basketball athletes, regardless of the amount of
playing time subjected to each participant.
Poster: 61
UTILITY OF BMI TO CORRECTLY CLASSIFY PERCENT BODY FAT IN OVERFAT
INDIVIDUALS
A. E. Smith-Ryan1, H. Wingfield2, M. Woessner2, M. N. Melvin3,
D. Fukuda4, S. Fultz2
1
University of North Carolina Chapel Hill, 2University of North Carolina,
3
University of North Carolina at Chapel Hill, 4Creighton University
Body mass index (BMI) is often used as a field-based assessment of health status
and obesity. Limitations exist when utilizing BMI in heavy populations, such as
football lineman and field competitors. Assessing obesity-related risk factors
accurately in these athletes could prevent future health-related comorbidities.
PURPOSE: To assess the accuracy of BMI to detect obesity when compared to a
four-compartment (4C) body composition criterion. A secondary purpose was
to evaluate the ability of BMI to detect differences in blood glucose, lipids and
insulin. METHODS: Forty-six men (M, n=19) and women (W, n=27)(Mean ± SD;
Age: 37.4 ± 11.6 yrs, Ht: 172.7 ± 10.0 cm, Wt: 94.2 ± 16.4 kg, %fat: 33.2 ± 5.4%) with
a BMI of ≥ 25kg∙m2 were assessed for body composition using a 4C approach. The
Wang-4C model was used to calculate percent body fat (%fat): [FM = 2.748(BV)
– 0.699(TBW) + 1.129(Mo) – 2.051(BM)], where body volume (BV) was measured
from air displacement plethysmography, total body water from bioelectrical
impedance spectroscopy, and total bone mineral content (Mo) derived from
dual-energy x-ray absorptiometry. Subjects were categorized as overweight
(OW; BMI ≥25kg∙m2) or obese (OB; BMI ≥ 30kg∙m2) and compared against the
age- and sex-matched %fat criterion classification as normal (%fat ≤ 19 for M;
≤33 for W); OW (%fat 19-27% for M; 33-40% for W) or OB (%fat >27% for M; and
>40% for W). Receiving operating characteristics (ROC) analyses were used to
determine optimal OW and OB BMI cutoff points by taking into account the best
combination of sensitivity and specificity values when compared to 4C %fat. The
kappa statistic was used to test the agreement between BMI and %fat. RESULTS: The diagnostic agreement between BMI and %fat for OW and OB was poor for
both men (kappa:0.123) and women (kappa:-0.125). BMI had poor specificity to
detect OB men (36%) and women (16%). Greater specificity occurred for the OW
population (93%). BMI miscategorized 79% of men and 37% of women. According
to the ROC, BMI is not a useful tool to assess overfatness (AUC=0.471; p=0.853)
in men. A BMI of 27.0kg∙m2 would be more accurate for identifying OW men. For
women, BMI may be useful for %fat classifications (ROC AUC=0.183; p=0.005)
with 25.5kg∙m2 providing 100% specificity for OW women. Independent samples
t-tests indicated significant differences in fasting blood glucose and insulin for only
OB women, as defined by %fat. Standard BMI was unable to detect differences
in glucose or insulin. CONCLUSIONS: The kappa statistic for men and women
suggests that classifications are not similar for BMI and %fat. More so, sensitivity
and specificity results suggest that BMI may be practical for OW women, but not
accurate for OW men. This data also demonstrates that higher BMI cutoffs are
needed for OW men and women to positively identify excess fat and associated
comorbidities. PRACTICAL APPLICATIONS: Athletes with higher %fat have been
shown to have a greater prevalence of obesity, resulting in associated health-risks. Because these athletes also have greater muscle mass, BMI may mask obesity.
While direct measurements of %fat may not be feasible, utilizing 27 and 25.5kg∙m2
as BMI cutoffs for men and women may be more effective for detecting health
risks in larger athletes. Direct measurement of metabolic syndrome markers,
rather than BMI, is still recommended. ACKNOWLEDGEMENTS: Supported by the
Nutrition Obesity Research Center (P30DK056350).
Poster: 62
ACCURACY OF FOOT-TO-FOOT BIOELECTRICAL IMPEDANCE ANALYSIS IN
COLLEGIATE FEMALE SOCCER PLAYERS
R. Snarr1, J. Verdy2, M. Esco3
1
Auburn Univeristy Montgomery, 2Auburn University at Montgomery,
3
Auburn University Montgomery
With a strong correlation between sports performance and body composition,
assessing body fat percentage in female athletes is crucial. Bioelectrical
impedance analysis (BIA) is an inexpensive field measure that can be used to
predict body fat percentage (BF%). However, these types of measures raise
questions as to the accuracy and reliability of predicting BF% in female athletes,
who typically tend to have a higher lean body mass and lower percentage of body
fat when compared to general population females. PURPOSE: The purpose of
this investigation was to cross-validate foot-to-foot BIA (FF-BIA) for predicting
BF% in female collegiate athletes by using dual energy x-ray absorptiometry
(DXA) as the criterion. METHODS: Eighteen female collegiate soccer players
(mean age = 21.5 ± 1.86, height = 65.89 ± 2.22 inches, weight = 142.8 ± 16.22 lbs.)
volunteered to have their BF% measured in this study. For each of the athletes,
FF-BIA was used to predict body composition and compared to DXA for criterion
purposes. RESULTS: The mean body fat percentage acquired from FF-BIA was
23.47 ± 5.84, while the mean DXA BF% was 27.41 ± 4.23. The mean values were
significantly different (p > 0.05). FF-BIA did not significantly correlated with the
DXA (r = 0.28, p = 0.26) and had a standard error of estimate (SEE) of 4.18%.
CONCLUSION: The findings suggest that FF-BIA significantly underestimates
BF% in female soccer athletes by 3.94% compared to the DXA and resulted in a
high SEE. PRACTICAL APPLICATIONS: Before using FF-BIA, practitioners should
be cautious of underestimating body fat percentage in female athletes, especially
considering a large SEE. Since body composition has a strong correlation with
sports performance, a more accurate method of predicting BF% in female athletes
may be warranted. In addition, misclassifying a female athlete’s body composition
could increase the risk of an eating or body image disorder. Therefore, body fat
prediction in female soccer players via FF-BIA should be performed with caution.
Poster: 63
A COMPARISON OF PERFORMANCE CHARACTERISTICS IN ELITE AND SUBELITE YOUTH SOCCER PLAYERS
P. Comfort1, A. Stewart2, L. Bloom3, B. Clarkson4
1
University of Salford, 2Hull Football Club, 3Charlton Athletic Football Club,
4
Southend United Football Club
Optimal sprint and jump performances are essential during soccer as these are
crucial events when ball position can be won and lost. During a soccer match
up to 11% of the time is spent sprinting, in bouts lasting 2-4 seconds, averaging
between 10m and 20m with an average of 90s recovery between sprints, covering
a total distance of approximately 650m during a match. PURPOSE: The purpose of
this study was to establish whether physical attributes can differentiate between
levels of competition in elite and sub-elite youth soccer players, which may aid in
the selection process within youth soccer. METHODS: Two groups of male soccer
players from youth elite (n=18, age 17.3 ± 0.6 years) and youth sub-elite (n=18,
age 17.4 ± 0.5 years) soccer clubs performed three countermovement jumps,
three squat jumps, three 20 m sprints, and 5 repetition maximum back squats
to predict maximal strength. Players from both squads were tested mid-season
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
during which time both squads were training full time with sessions comprising
all of the elements of performance including 4-5 (8-10 hours/week) soccer
specific training sessions per week, plus two (2 hours/week) resistance training
session each week. At the time of testing both squads were at the end of a power
meso-cycle. RESULTS: Intraclass correlation coefficients revealed that sprint and
jump assessments were all highly reliable (r≥0.85, p<0.001), excluding 5m sprint
performances for the AC squad, which showed only a moderate reliability (r=0.69,
p=0.01). Independent t-tests revealed no significant differences (p>0.05) in the
height (175.1 ± 5.4 cm vs. 171.8 ± 5.8 cm) and body mass (69.5 ± 6.9 kg vs. 68.1
± 5.8 kg) of elite and sub-elite squads respectively. In contrast the elite squad
demonstrated significant quicker sprint performances over 5m (0.98 ± 0.05 s vs.
1.02 ± 0.06 s; p=0.01) and 20m (2.95 ± 0.09 s vs. 3.06 ± 0.15 s; p=0.003), higher
squat jump (51.8 ± 3.9 cm vs. 37.8 ± 3.8 cm; p<0.001) and countermovement jump
(55.1 ± 4.5 cm vs. 38.6 ± 3.9 cm; p<0.001) performance along with significantly
greater relative predicted maximal squat strength (2.14 ± 0.25 kg/kg vs. 1.81 ± 0.34
kg/kg, p<0.001) compared to the sub-elite squad, respectively. CONCLUSIONS:
Results suggest that strength, jump and sprint performances differentiate
between elite and sub-elite youth level soccer players, and may be useful during
athlete selection by coaching staff. PRACTICAL APPLICATIONS: These findings
highlight the importance of appropriate conditioning to develop strength and
power in youth soccer players as they clearly differentiated between the two
levels of competition.
Poster: 64
PREDICTION OF STANDING LONG JUMP POWER IN NCAA DIVISION IA
FOOTBALL PLAYERS
B. Mann1, M. Bird2, P. Ivey3, T. Jackson2, K. Stump2,
B. Daniels2, J. L. Mayhew2, S. Sayers4
1
University of Missouri, 2Truman State University, 3University of Missouri,
4
Physical Therapy Department, University of Missouri
The vertical jump is a popular measurement for determining leg power. The
application of force in a single plane allows convenient determination of power
using a force plate. Various prediction equations exist to estimate power from
combinations of vertical jump height, body mass, and standing height. Despite
the popularity of the standing long jump (SLJ), limited research has explored
the prediction of power from this test. PURPOSE: To determine the feasibility
of estimating SLJ power from jump distance and selected anthropometric
dimensions in NCAA Division IA football players. METHODS: 58 players (Height
= 184.9 ± 6.6 cm; weight = 102.5 ± 18.1 kg) were measured during an off-season
winter conditioning program. Measurements included height, body mass, total
lower extremity length (TLE), and shank length (SL). TLE was measured from
the greater trochanter to the floor. SL was measured from the joint space of the
knee to the floor. Thigh length (TL) was calculated as the difference between TLE
and SL. Leg ratios of TLE/Ht and TL/SL were also calculated. Players completed
general and specific warm-ups before performing 2-3 maximal familiarization
trials of SLJ. Following a minimum of 5 mins rest, each player performed 2
maximal SLJ trials from a force plate. Each trial was separated by approximately
1 min rest. Vertical and horizontal forces were sampled at 1000 Hz and used to
calculate power in each direction. SLJ power was calculated from the resultant
force and velocity vectors. Best SLJ and peak power were used for analysis. RESULTS: The 2 SLJ trials were not significantly different (265.2 ± 25.9 and 268.2
± 25.9 cm, p = 0.07) and highly reliable (ICC = 0.944). Peak power from the 2
trials were not significantly different (5,068 ± 939 and 5,131 ± 905 W, p = 0.34) and
highly reliable (ICC = 0.926). Standing height (r = 0.40), weight (r = 0.36), FLL
(r = 0.43), TLL (0.38), and best SLJ (r = 0.52) were significantly related (p<0.05)
to peak power. Only weight (r = -0.47) was significantly related to SLJ range;
all other measurements had correlations only between -0.15 to 0.04. Step-wise
multiple regression selected SLJ range and weight as the only significant variables
to predict peak power: Power (W) = 32.49 SLJ (cm) + 39.69 Weight (kg) – 7608
(R = 0.86, SEE = 488 W, CV% = 9.3%). SLJ contributed 56.8% to the known
variance, while weight contributed 43.2%. CONCLUSION: This is the first study
to estimate power production from a standing long jump in athletes. Although
football players produce an average SLJ that was 13% greater than previously
measured in recreationally active subjects, their peak power was significantly
greater due largely to their greater average weight. SLJ and body mass are similar
contributors to power generation in football. PRACTICAL APPLICATION: SLJ and
weight can be used as effector predictors on SLJ power in major college football
players. Poster: 65
CONCURRENT VALIDITY OF A NOVEL HEART RATE MONITOR STRAP
D. Looney1, C. Dunn-Lewis1, B. Comstock1, D. Hooper1, T. Szivak1,
S. Flanagan1, A. Sterczala1, W. DuPont1, C. Giacchino1, E. Webster1,
D. Dombrowski1, D. McDermott1, W. J. Kraemer1
1
University of Connecticut
PURPOSE: New Technology offers potential advantages in physically demanding
environments where convenience and comfort are important and accurate and
reliable data collection is challenging. Nevertheless, it is important to validate the
accuracy and reliability of such biological monitoring systems (BMS) before they
are adopted. The purpose of the present investigation was to assess the concurrent
validity of a new heart rate monitor across a range of exercise intensities and with
a large and diverse group of male subjects. METHODS: Seventy-five men (Age:
23 ± 4 y; Height: 181 ± 8 cm; Body Mass: 83 ± 12 kg; estimated VO2peak 3.16 ± 0.63 [L
● Min -1]) volunteered and completed a graded cycle ergometer exercise protocol
while heart rate was continuously monitored before, during, and after exercise
with the new novel multi-function heart rate monitoring device (model blinded
by abstract requirements) and the gold standard (electrocardiogram). The twominute stages included sitting, standing, and cycling with 35 W increments until
volitional fatigue. RESULTS: The coefficient of determination between mean heart
rate values at each stage was R2 = 0.99, while Pearson correlations at each stage
were ≥ r = 0.99. Heart rates during exercise were typically within one beat of each
other. CONCLUSIONS: The biological monitoring system therefore represents a
convenient device for valid and reliable measures of heart rate under various bodily
positions and levels of exertion, including maximal exercise intensity. It reality it
was more stable than the EKG for preventing signal artifacts in the EKG tracings. PRACTICAL APPLICATIONS: The use of a mobile valid monitoring system is vital
for optimal monitoring of training intensities with exercise programs.
Poster: 66
SYSTEMATIC REVIEW OF CORE MUSCLE ACTIVITY DURING PHYSICAL FITNESS
EXERCISES
J. M. Martuscello1, J. L. Libous1, J. M. Mayer1
1
University of South Florida
PURPOSE: Core muscle strength and stability exercises are often prescribed by
strength and conditioning specialists for their athletes and clients in order to
enhance fitness performance and prevent injury in a variety of activities. However,
an evidence-based consensus has not been reached regarding which physical
fitness exercises are most effective at stimulating the activity of the core muscles.
Furthermore, the scientific literature on this has not been systematically reviewed.
Thus, the purpose of this paper was to systematically review the literature on
the electromyographic (EMG) activity of three important core muscles (lumbar
multifidus, transverse abdominis, quadratus lumborum) during physical fitness
exercises in healthy adults to identify evidence-based knowledge. METHODS:
Major scientific databases (i.e. CINAHL, Cochrane Central Register of Controlled
Trials, EMBASE, PubMed, SPORTdiscus, and Web of Science) were searched for
relevant articles using a search strategy designed by the investigators. Physical
fitness exercises were partitioned into five major types: traditional core, core
stability, ball/device, free weight, and non-core free weight. Strength of evidence
was assessed and summarized for comparisons among exercise types. RESULTS:
Seventeen studies enrolling 252 participants met the review’s inclusion/exclusion
criteria. The key findings of this review with moderate levels of evidence were
as follows: 1) lumbar multifidus EMG activity is greater during free weight
exercises compared with ball/device exercises, and similar during core stability
and ball/device exercises; 2) lumbar multifidus EMG activity is similar during core
stability exercise and ball/device exercises; and 3) transverse abdominis EMG
activity is similar during core stability and ball/device exercises. No studies were
uncovered for quadratus lumborum EMG activity during physical fitness exercises.
CONCLUSIONS: This systematic review revealed no evidence to suggest that
core-specific exercises (core stability, ball/device) result in greater EMG activity
of three major core muscles compared with traditional, multi-joint free weight
exercises. PRACTICAL APPLICATIONS: The available evidence suggests that
strength and conditioning specialists should focus on prescribing multi-joint free
weight exercises for their athletes and clients, rather than core-specific exercises,
in order to adequately train the core muscles. Along with providing an adequate
stimulus for the core muscles, multi-joint free weight exercises provide additional
health benefits that are not associated with core-specific exercises, which further
supports the use of free weight exercises versus core-specific exercises.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 67
Poster: 68
THE INFLUENCE OF CROSSFIT ON FITNESS IN MEN AND WOMEN
THE IMPACT OF LOW-LOAD TRAINING WITH PARTIAL VASCULAR OCCLUSION
ON CYCLE ERGOMETER PEAK POWER
B. Church1, C. Jeffery1, M. Jones1, A. Wheeler1,
T. Adams1, J. Stillwell1
1
Arkansas State University
C. Popovici1, J. Hokanson2
1
PURPOSE: CrossFit is a relatively new type of exercise that has been growing in
popularity. This form of exercise aims to improve general fitness through a variety
of exercises including both bodyweight training and weight training among other
non-traditional methods. The purpose of this study was to compare fitness levels
in CrossFit trained individuals with a control group who have exercised with more
traditional forms of exercise. A second purpose of this study was to determine the
relationship between three common CrossFit exercises: 1-RM deadlift, 1 minute row
for distance, and a timed test known as Murph by CrossFit practitioners. METHODS: Thirty seven participants, both male (n = 30) and female (n = 7) participated
in the study. Participants were divided into two groups, CrossFit (15 males, 4
females), which regularly exercised according to CrossFit recommendations, and
control (15 males, 3 females), which followed traditional exercise as suggested by
the American College of Sports Medicine (ACSM). Participants completed the
Margaria-Kalamen Power Test, Anaerobic Step Test, and Cooper 1.5 mile run. Means
and standard deviations, along with independent t-tests were run based on test
group and sex. RESULTS: It was found that male CrossFit participants performed
significantly better, t(30) = 2.21, p<.05 (Crossfit: 1395W±379, Control: 1210W±287),
than control males on the Maragaria Kalamen Power Test. Although mean scores
for CrossFit participants were greater than control for the remaining tests, none
reached the significance criterion of p<0.05 in either male or female participants. In addition, no significant correlations were observed between deadlift 1-RM, one
minute row, and the timed Murph CrossFit workout. CONCLUSION: Based on
these results the CrossFit method of training is just as effective as more traditional
methods of aerobic and strength training advocated by the ACSM. Exercise
adherence is often a problem with individuals who want to achieve minimum
health standards. CrossFit appears to be an additional type of exercise that may
be used to help individuals exercise regularly; thus, achieving adequate fitness
levels associated with optimal health. PRACTICAL APPLICATION: This was one
of the first studies ever on CrossFit and the main results indicated that individuals
participating in CrossFit can achieve fitness levels at or above levels compared to
the general ACSM recommendation for fitness.
Physical Education Department, State University of New York at Oneonta,
2
Kinesiology Department, State University of New York at Cortland
Increases in muscle hypertrophy have been achieved with the use of low-intensity
(<50% 1RM) single joint resistance exercises in conjunction with partial vascular
occlusion of active muscle tissues, resulting in strength increases of upwards of
40% of maximal voluntary contractions. Traditionally, similar gains in strength have
only been elicited under conditions involving high-intensity resistance training at
or above 80% 1RM. Proposed mechanisms for these adaptations include hypoxiainduced additional or preferential recruitment of fast-twitch muscle fibers and a
longer exposure of tissues to metabolic acidosis through the shunting of venous
return and the accumulation of intramuscular H+ ions. These mechanisms are
thought to elicit an exaggerated hormonal response than is traditionally seen
when using intensities of <50% 1RM. To date, little research exists examining the
potential of occlusion training as a means to improve power output. Based upon
the proposed mechanisms responsible for adaptations resulting from occlusion
training, such as a preferential recruitment of fast twitch fibers to perform a low
resistance task; it would seem plausible that neuromuscular gains can be made. Purpose: Based upon these previous proposals of modified neural recruitment
patterns and increased fast twitch involvement during hypoxic conditions created
through a disruption to vascular blood flow, this study sought to determine if
partial vascular occlusion of working musculature could enhance peak power
on a cycle ergometer, measured using 30 second Wingate Test. Method: 21
recreationally active college students were separated into three training groups: A
low-load occluded group (LLO)(n=7), a low-load free-flow group (LL)(n=7) and a
high-load free flow group (HL)(n=7) and completed a 10 session, 5 week training
protocol with additional pre and post Wingate Tests. All groups trained using
the same periodized program designed to increase peak power output. Groups
trained twice per week. Each session involved short sprint intervals at a maximum
cadence ranging in time from 4 to 10 seconds per repetition, with 4 to 8 repetitions
per session with 1:6 work to rest ratio. Sessions last approximately 10-15min. HL
trained at 95% of the resistance used during Wingate testing (7.125% of BW) while
the low-load groups (LL and LLO) trained at 45% of their Wingate test resistance
(3.375% of BW). LLO participants wore 6x33cm blood pressure cuffs around the
proximal segment of the thigh, just below the hip for the duration of the training
session. The cuffs were inflated to 180mmHg and the researchers monitored this
pressure. Results: Pre and post training Wingate data was compared. Subjects
in LLO and HL both improved significantly from pre to post testing in relative
peak power (W/kg), 14.4% and 14.1% respectively (p > .05), while individuals in
LL saw no significant improvement in relative peak power (4.6%). LLO improved
significantly over LL (p = .041), while HL’s improvement over LL nearly reached
significance (p = .082). Average total work performed during training was
calculated (in Watts). After ten training sessions LLO generated an average per
person total work output of 8,204W, 58.3% less than HL’s 19,664W (p < .005). Conclusions: Utilizing low-resistance training under partially occluded conditions
during sprinting on a cycle ergometer results in significant improvement to relative
peak power output as measured during a Wingate Test. Practical Applications:
The less overall work needed to produce significant affects in training compared to
traditional methods indicates that occluding venous flow can provide an efficient
stimulus towards increase muscular power for a specific movement pattern. Due
to the minimal amount of work (2 ten minute sessions per week) which resulted in
significant improvements to peak-power, this training modality may be attractive
to in season athletes, if specific movement patterns can be duplicated under
occluded conditions, or as an additional training modality to any power program.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Friday, July 12, 2013, 8:30 AM - 8:45 AM
AEROBIC CAPACITY AND MUSCULAR ENDURANCE IMPROVEMENTS WITH
FOUR WEEKS OF BATTLING ROPE HIGH INTENSITY INTERVAL TRAINING
C. A. McAuslan1, K. Milne1, K. Kenno1
1
University of Windsor
*Award Eligible - Outstanding Master’s Student Podium Presentation
High intensity interval training (HIIT) is a form of cardio-respiratory training
where a selected exercise, traditionally cycling or treadmill running, is performed
for a specified amount of time (usually 1 min or less) followed by a specified
rest/recovery interval. This workout is then repeated for a specified number of
work/rest intervals typically varying from 4-10 sets, 2-5/week, for 4-6 weeks of
training. Recently, large diameter ropes (1-2 inches) weighing 20 to 75 pounds
called battling ropes have emerged as an alternative upper body interval training
apparatus used to improve the aerobic/anaerobic energy systems and muscular
endurance. Strength and conditioning professionals are utilizing battling ropes
with little or no published research to substantiate their effectiveness as a
training regiment. PURPOSE : To determine the aerobic and muscular endurance
responses to a 4 week HIIT battling rope training protocol. METHODS : Thirty
moderately active university aged participants (mean age 22yr) (15 women, 15
men) volunteered to train 3x/week, for a 4 week HIIT battling rope conditioning program. The training program consisted of a 30 second maximal work interval,
alternating between the double-whip and alternating whip exercises, separated
by a 60 second recovery period for a total of 10 work/rest training rounds. Women
used a 40 ft, 1.5 inch rope and men used a 50 ft, 1.5 inch rope. Pre and post
testing included handgrip strength, pushups and bent-knee situps for muscular
endurance and an arm ergometer maximal aerobic capacity test to assess
oxygen consumption adaptations. RESULTS : During the 4 week battling rope
HIIT, the average heart rate during the 10 work intervals was 175 bpm. Following 4
weeks of battling rope HIIT, participants improved their arm ergometer aerobic
capacity 4.94% (p < 0.05), pushup performance 23.56% (p < 0.001), bent-knee
situp performance 6.67% (p < 0.01) , while handgrip strength did not improve.
CONCLUSION : Four weeks of battling rope HIIT significantly improves maximal
upper body aerobic capacity, upper body and core muscular endurance and had
no effect on handgrip strength. PRACTICAL APPLICATIONS : High intensity
battling rope interval training protocols offer an effective, alternative and unique
upper body training experience that strength and conditioning professionals
should consider implementing to improve upper body aerobic capacity and
muscular endurance.
Friday, July 12, 2013, 8:45 AM - 9:00 AM
RELIABILITY AND VALIDITY OF A NOVEL FIELD-BASED HAMSTRING STRENGTH
TEST FOR ASSOCIATION SOCCER PLAYERS: IMPLICATIONS FOR PREVENTING
HAMSTRING INJURIES
J. W. Lee1, P. S. Yung1, H. C. Chan1, K. Chan1
1
The Chinese University of Hong Kong
*Award Eligible - Outstanding Doctoral Student Podium Presentation
PURPOSE: Isokinetic knee strength test is considered as a useful method for
professional soccer players to identify the risk of sustaining hamstring strains.
However, those testing protocols were time consuming and inconvenient.
Therefore, a novel field-based strength test for evaluating hamstring strength was
designed. The aim of this study is to examine the reliability and validity of this test
for soccer players. METHODS: 30 amateur players (mean age =17.2 ± 1.27 years;
body weight = 62.98 ± 7.87kg; height = 175.32 ± 5.23cm) from HKFA 2nd division
league participated in this study. The CUHK hamstring strength test included 3
different modes (free mode, 15°mode, and 30°mode). The subjects started in
a kneeling position and a helper stabilized the subjects’ legs. Then the subject
leaned forward in a smooth and controlled manner, while keeping his back and
hips fully extended until the point he has to let go with hamstrings. The free mode
was tested for the forward flexion angle which the subjects cannot sustain. The
15° mode and 30° mode were tested for the time that the subjects could hold at
15° and 30° respectively. High speed camera was used to record the performance
of the CUHK hamstring strength tests. A motion analysis system APAS is used
to analysis the tilting angle and angular velocity of knee joint. Hamstring peak
torque and Hamstring to Quadriceps (H/Q) strength ratio of the isokinetic test in
3 different patterns of speed were used as the criterion for the validity test. The
testing protocol included concentric performance of hamstring and quadriceps
muscle groups at 60 deg/s (3 repetitions), 240 deg/s (5 repetitions) angular
speeds, and the eccentric performance of the hamstrings at 30 deg/s. All sets of
testing were separated by 1 minute of rest. Intra-class correlation coefficient (ICC)
was used to analyse the reliability between test and retest in all 3 modes of CUHK
hamstring strength test. Correlations between the independent and dependent
variables were tested to screen for the potential variable which may predict the
hamstring strength. Linear regression was used and the statistical significance
was determined at p<0.05. RESULTS: The CUHK hamstring strength test 1 was
the most reliable test (R=0.815) among the CUHK hamstring strength test. This
test can predict the hamstring peak torque in concentric performance at 60°/s
and 240°/s angular speed. The combination of angle in free mode test and body
weight can predict a larger percentage of data. CONCLUSIONS AND PRACTICAL
APPLICATIONS: We suggest that soccer players can adopt this field based test
during preseason to identify hamstring weakness. Coaches can adopt appropriate
injury prevention exercise for those players with hamstring weakness.
Friday, July 12, 2013, 9:00 AM - 9:15 AM
THE INFLUENCE OF AGE ON PASSIVE STIFFNESS OF THE
PLANTAR FLEXOR MUSCLES
E. J. Sobolewski1, E. D. Ryan1, B. Thompson2, E. C. Conchola2
1
The University of North Carolina at Chapel Hill, 2Oklahoma State University,
Applied Musculoskeletal and Human Physiology Lab, Stillwater, OK
*Award Eligible - Outstanding Doctoral Student Podium Presentation
With a rapidly growing elderly population, it is essential to expand our understanding
of the influence of aging on passive properties of the musculotendinous unit. Previous studies have reported inconsistent findings regarding then changes in
passive stiffness and very few studies have examined these changes across the
lifespan. PURPOSE: The purpose of this study was to examine the effects of
aging on the passive stiffness of the plantar flexors in young, middle-aged and
old men. METHODS: Sixteen young (mean ± SD: age = 22±2 yr), fifteen middleaged (47±2 yr), and sixteen old (66±4 yr) men performed a passive stiffness
assessment of their right plantar flexors on a calibrated isokinetic dynamometer. To determine passive stiffness, the lever arm passively dorsiflexed the ankle at 5°/s
starting at 20° of plantar flexion to the participants maximally tolerated range of
motion (MROM) at which point the dynamometer was manually stopped by the
investigator and immediately returned to the starting position. The angle-torque
curve was gravity corrected for the weight of the footplate and fit with a 4th
order polynomial function. Passive stiffness values were calculated as the slope
of the angle-torque curve at a common joint angle (10° of dorsiflexion; neutral =
0°) and a relative joint angle (80% of MROM) using a 200ms epoch. All passive
stiffness values were normalized to corrected calf-girth measurements. Common
and relative angle passive stiffness values were evaluated using two, one way
ANOVAs with post hoc Bonferroni corrected independent t-tests. A type-1 error
rate of 5% was used to determine statistical significance. RESULTS: For common
angle passive stiffness, the older men exhibited greater stiffness values when
compared to the young and middle-aged men (P≤0.003). Similarly, relative angle
passive stiffness values were also greater in the older men when compared to the
young and middle-aged men (P≤=0.017). CONCLUSION: The results of this study
indicated that no differences were observed in passive stiffness values between
the young and middle-aged men at either a relative or common joint angle;
however, both groups exhibited lower passive stiffness values when compared to
the old men. PRACTICAL APPLICATION: These findings demonstrated that over
the course of the life span, passive stiffness of the plantar flexors increases at old
age. However, these changes appear to occur sometime after middle-age (i.e.
47 years) in healthy men. These findings may also highlight the importance of
including training interventions in older adults to help reduce passive stiffness.
Friday, July 12, 2013, 9:15 AM - 9:30 AM
12 WEEKS OF ORAL ATP SUPPLEMENTATION INCREASES STRENGTH,
POWER, AND LEAN BODY MASS
J. M. Joy1, R. P. Lowery1, J. E. Dudeck1, M. A. Naimo1, E. Oliveira de Souza2,
S. A. McCleary1, S. I. Weiner1, J. M. Wilson1
1
University of Tampa Human Performance Lab, 2Laboratory of Neuromuscular
Adaptations to Strength Training, School of Physical Education and Sport,
University of São Paulo
*Award Eligible - Outstanding Master’s Student Podium Presentation
Purpose: Currently, there is a lack of studies examining the effects of adenosine
triphosphate (ATP) supplementation utilizing a long term, periodized resistancetraining program (RT) in strength-trained populations. Therefore, we investigated
the effects of 12 weeks of 400 mg per day of oral ATP on neuromuscular
adaptations in trained individuals. We also sought to determine the effects of
ATP on muscle damage, cortisol, and performance during an overreaching cycle.
Methods: The study was a 3-phase randomized, double-blind, placebo and dietcontrolled intervention. Phase 1 was a periodized resistance-training program. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Phase 2 consisted of a two week overreaching cycle in which volume and frequency
were increased followed by a 2-week taper (Phase 3). Muscle mass, strength, and
power were examined at weeks 0, 4, 8, and 12 to assess the chronic effects of ATP;
assessment of performance variables also occurred at the end of weeks 9 and
10 (the mid and endpoints of phase 2). Additionally, urinary 3-methylhistidine
(3-MH) and blood draws following a 12-hour fast for resting testosterone and
cortisol, C-reactive protein (CRP), creatine kinase, and creatinine were obtained
for weeks 0, 8, 9, 10, and 12. Blood draws occurred at the same time of day to
avoid diurnal effects. Muscle protein degradation was measured by the ratio of
urinary 3-MH:creatinine. A Repeated measures ANOVA was used to assess main
effects in all variables. Tukey post hoc was employed to locate where differences
occurred. Statistical significance was determined at p ≤ 0.05. Results: There
were time, and group x time effects (p<0.05) for strength (12.6% ATP vs 5.9%
placebo) power (15.7% ATP vs 11.6% placebo), and muscle mass (9.4% ATP vs
4.9 % placebo), which increased greater in the ATP group. For the overreaching
cycle, there were group x time effects for strength and power, which decreased
to a greater extent in the placebo group. Muscle damage, assessed by blood
CK, and muscle protein degradation were affected by training (Time, p < 0.05). Supplementation with ATP was unable to attenuate the increase in CK during
both the initiation of training (weeks 0 to 1) and during the overreaching cycle
(weeks 9 and 10). ATP supplementation significantly decreased muscle protein
degradation compared with placebo during the overreaching cycle (Trt*time,
p < 0.007). Supplementation with ATP did not affect changes in C-Reactive
protein, cortisol, or free or total testosterone levels when compared with placebo
supplementation. Conclusions: The collective findings of our current study suggest
that supplementation with ATP, in combination with high intensity, periodized
RT, increases LBM, muscle mass, strength, and power versus a placebo-matched
control. Moreover when faced with greater training frequencies, oral ATP may
prevent typical declines in performance that are characteristic of overreaching. Future research should seek to elucidate the underlying mechanisms through
which ATP operates to promote improvements in training adaptations.
Friday, July 12, 2013, 9:30 AM - 9:45 AM
COMPARISONS OF ACUTE NEUROMUSCULAR FATIGUE IN MAXIMAL EFFORT
STRENGTH TRAINING USING POWERLIFTS
N. T. Theilen1, B. I. Campbell2, M. C. Zourdos3, J. M. Oliver4,
J. O’Halloran2, N. Asher2, J. Wilson5
University of South Florida, 2University of South Florida/Exercise and
Performance Nutrition Laboratory, 3Florida Atlantic University, 4Department of
Kinesiology, Texas Christian University, Fort Worth, TX, 5University of Tampa
1
*Award Eligible - Outstanding Master’s Student Podium Presentation
Purpose: To assess the level of acute neuromuscular fatigue, as measured by a
decrease in peak velocity, as a result of maximal effort strength training sessions
with each powerlift (squat, bench press, deadlift). Methods: Twelve resistance
trained males (22.8 ± 2.6 yrs; 177.1 ± 6.7 cm; 83.0 ± 12.6 kgs) participated in a
randomized crossover design with three conditions: Squat (SQ), Bench Press (BP),
and Deadlift (DL). Subjects’ relative strength included the ability to successfully
complete atleast 1.5x their bodyweight in the squat exercise. Initially, baseline
peak velocity (PV) was measured for each lift at 60% 1RM via a TENDO Power
and Speed Analyzer. One training session occurred each Monday for 3
consecutive weeks (1 week for each lift). Each training session consisted of a
1RM of the designated lift followed by 4 sets of 2 repetitions at 92.5% and 4 sets
of 3 repetitions at 87.5%. In the days following training sessions, each lift PV
was measured at 24, 48, and 72 hours post-training to compare with baseline
measures and determine recovery. Data was analyzed using a repeated measures
ANOVA (p<.05). Results: SQ: No significant differences in PV of the SQ and DL
following SQ training at each time point compared to baseline. Bench press PV
significantly declined following squat training (Baseline = 1.069 m/s; 24 hours =
0.974 m/s [p = 0.019]; 48 hours = 1.015 m/s [p = 0.034]; 72 hours = 0.970 m/s
[p = 0.004]. BP: No significant differences in PV of the SQ and DL following BP
training at each time point compared to baseline. Bench press PV significantly
declined only at 24 hours following BP training (Baseline = 1.069 m/s; 24 hours =
0.988 m/s [p = 0.004]). DL: No significant differences in PV of the DL following
DL training as compared to baseline. Squat PV significantly declined at 24 hours
following the DL training (Baseline = 1.384 m/s; 24 hours = 1.315 m/s [p = 0.032]. Similar to SQ, PV of the BP significantly declined only at 24 hours following DL
training (Baseline = 1.069 m/s; 24 hours = 0.979 m/s [p < 0.001]). Conclusions:
Bench press PV was significantly decreased 24-hours following each of the three
powerlifts as compared to baseline values. Interestingly, there were no changes in
squat and deadlift PV following training of that specific lift. Practical Applications:
Regardless of the powerlift trained, bench press PV at 60% was compromised
24-hours later. Therefore, following training of any powerlift, more than
24-hours may be needed to optimize performance in the BP at submaximal
intensities. Acknowledgements: This investigation was supported by Dymatize
Nutrition Sport Performance Institute.
Friday, July 12, 2013, 9:45 AM - 10:00 AM
THE EFFECTS OF A CORE STRENGTH TRAINING PROGRAM ON FIELD TESTING
PERFORMANCE OUTCOMES IN JUNIOR ELITE SURF ATHLETES
T. A. Axel1
1
California State University, Long Beach and Dean Sports Consultants
*Award Eligible - Outstanding Master’s Student Podium Presentation
PURPOSE: Competitive surfing requires athletes to transfer force from their
core musculature to maneuver a surfboard successfully with powerful, rotational
movements while riding an unpredictable wave’s surface. Previous research
has documented aerobic and anaerobic measurements of competitive and
recreational surfers paddling performance. However, to date no research has
documented the junior elite competitive surfer’s core musculature and lower
body athletic performance measurements. A test-retest, quasi-experimental
design using a battery of field tests specific to the sport of surfing was used to
determine the effects of an 8-week core strength training program (CSTP) on
athletic performance measures. METHODS: Nineteen junior elite surf athletes
(age 15.7±1.01yrs, height 1.77±0.007m, mass 64.67±9.08kg) completed a pre-test,
8-week CSTP, and a post-test of rotational power (RP), lower body power (LBP),
core strength (CS), core endurance (CE), and rotational flexibility (RF). Means,
standard deviations, paired t-tests with a significance level of p < 0.05, and effect
sizes were computed. Bilateral time to peak acceleration, maximal acceleration,
and RP were measured utilizing a dumbbell equipped with a 3D accelerometer
and an external dynamometer. LBP was measured using a vertical jump (VJ)
test. CS was measured using a 2kg medicine ball toss while CE was measured via
timed prone plank. RF was measured using a dynamic trunk rotation flexibility
test. Each participant performed 3 trials for each test and received a minimum
of 2 minutes of rest between each trial. The trial indicating maximal performance
for each test was used in the statistical analysis. RESULTS: The 19 participants
had a significant decrease from pre-test to post-test in right side time to peak
acceleration, t(18)= 2.38, p=0.014, r=0.49. There was a significant decrease in left
side time to peak acceleration from pre-test to post-test, t(18)=3.18, p=0.0026, r=
0.60. A significant increase was found in pre-test to post-test in left RP, t(18)=2.78, p=0.006, r=0.55. There was a significant increase in right and left side CS
from pre-test to post-test, t(18)=-2.75, p=0.007, r= 0.54 and t(18)= -3.93, p=
0.0005, r= 0.68, respectively. A significant increase was observed for CE, t(18)=
-2.05, p= 0.03, r= 0.44. In addition, a significant increase was observed for RF,
t(18)=-5.69, p= 1.07 E-1, r= 0.80. All means and standard deviations are presented
in the table. DISCUSSION: Results demonstrated significant improvements in time
to peak acceleration, left RP, CS, CE, and RF. Based on the results, we conclude
implementation of the CSTP enhances athletic performance measurements which
will likely increase overall surfing performance. PRACTICAL APPLICATIONS: The
CSPT is an effective training tool for surf coaches and strength and conditioning
professionals to improve strength in the core musculature and lower body. In
addition, the CSTP was designed specifically for junior elite surfers; however, the
results may be applicable to all surf athletes.
Friday, July 12, 2013, 10:00 AM - 10:15 AM
HITTING A MOVING TARGET: EFFECTS OF PHYSIOLOGICAL STRESS ON
ACCURACY AND RECALL IN POLICE FIREARMS TRAINING
S. Unruh1, B. Goslin1
1
Oakland University
*Award Eligible - Outstanding Master’s Student Podium Presentation
Law enforcement firearms qualification and training are measured against static
targets and low stress. Yet, real life deadly force encounters involve moving
targets and high stress. PURPOSE: Target Focus Shooting (TFS not using the
sights) and Isosceles Shooting (IS: using the sights) were examined for hitting
a moving target at rest and after exercise stress. METHODS: Thirty-three
participants were recruited from two independent groups (n = 22 for TFS and n =
11 for IS). Both groups fired as often as possible at a moving target using soaplike colored cartridges at a distance of 3.04+0.15 m, once at rest and again after
significant exercise stress induced by a 30 s Wingate bicycle test. The Wingate
bicycle test involves supra-maximal effort that increases heart rate through muscle
fatigue that is comparable to what a police officer may experience during a critical
incident. The target moved from right to left at 0.914 m/s over a 2 m distance. A recall test was conducted after the post-exercise session for memory of shots
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
fired and perceived success. Performance was measured by Points (Pts) assigned
(Hit (+1); Miss (-2), Did Not Shoot (DNS) (0)), Pts; Rounds Shot (Rnds); Hit/Total
% (Hit%). A composite score (CS) was calculated [CS= Pts x Rnds x (1÷Hit%)]
and analyzed by a mixed design ANOVA (α< .05). RESULTS: There was no
significant shooting style effect (p = .37), exercise stress had no significant effect
(p =.68), and there was no interaction (p =.65). The CS means for the IS style
were superior (mean+SD: Pre-Stress 2.0+4.83, Post-Stress 2.63+4.10) to the TFS
style (mean+SD: Pre-Stress -1.21+13.17, Post-Stress -0.30+11.45) and both shooting
styles deteriorated with exercise stress, but not significantly. Round placement
and accuracy was analyzed and the average Hit % at Rest (TFS: 74%; IS: 84%) was
higher than Post-Exercise (TFS: 59%: IS: 73%). Post-exercise memory recall of the
number of shots and perception of the number hitting the target was quite low
(TFS: 29%; IS: 24%). CONCLUSION: Sighted shooting (IS) is best when shooting
at moving targets. Exercise stress causes a deterioration of shooting accuracy,
but not significantly. PRACTICAL APPLICATION: High intensity exercise causes
deterioration in shooting performance. Firearms training should emphasize the
use of the weapon’s sights, physical fitness, and practice with moving targets for
optimal performance.
Friday, July 12, 2013, 10:15 AM - 10:30 AM
TRENDS FROM NFL COMBINE DATA MAY PREDICT PERFORMANCE
VALUES OF FUTURE NFL DRAFT PICKS
K. A. Leiting1, B. Gleason1
1
East Tennessee State University
*Award Eligible - Outstanding Doctoral Student Podium Presentation
PURPOSE: The purpose of this research is to provide coaches and athletes with
minimum performance values to establish as goals for the 2014 NFL Combine.
METHODOLOGY: All subjects were invited to compete in the NFL Combine
and their data are available to the public. All NFL Combine data from 19992012 have been “scraped” from http://nflcombineresults.com/nflcombinedata.
php and all draft pick history “scraped” from http://www.nfl.com/draft/history/
fulldraft?position on November 27, 2012. All NFL draft picks and their draft pick
rank were matched with NFL Combine data from the respective year of the
athletes’ draft and NFL Combine results. NFL combine data of individuals that
were not drafted were not used for analysis. Aggregate data for each year and
position and performance variable were graphed and trends were established by
applying the derived slope-intercept linear equation. Peak Power is not an NFL
Combine assessment but can be derived from NFL Combine data using the Sayers
Power Equation. Two standard error of estimate (SEE) was used to determine
a cut-off point that became the minimum performance value. The minimum
performance value for each position and event for 2014 is provided. Data from
1999-2011 were used to determine already known 2012 performance values as
a means of validation. Percent of non-overlapping data was used to assess the
percent success rate for this method. The number of participants that achieved
a performance value greater than the predicted minimum for 2012 were divided
by the total number of participants that were drafted is termed success rate.
RESULTS: Minimum performance values for each position for each event for the
2014 Combine are presented. Validation of this method of analysis is presented
as a success rate for each position and event. DISCUSSION: This method of
analysis has a 69-84% success rate at identifying the minimum performance
value depending upon position. To the investigators knowledge there has not
been an attempt to identify performance values that increase potential draft
selection. It interesting to note the low success rate for some variables based on
position, suggesting not all NFL Combine tests are applicable to every position.
PRACTICAL APPLICATIONS: Performance values presented may be used as a
goal for strength coaches to help athletes achieve at the NFL Combine in 2014.
Achieving performance values greater than the minimum presented may increase
an athletes’ chance of draft selection. It is suggested that this method of analysis
should be continually updated and evaluated to identify minimum performance
values for upcoming NFL Combines.
Friday, July 12, 2013, 10:30 AM - 10:45 AM
LOWER-BODY STRENGTH AND POWER INFLUENCE PERFORMANCE IN
CHANGE OF DIRECTION TASKS
F. A. Bourgeois1, J. B. Winchester1, R. W. Brem1,
F. B. Wyatt1, S. P. Cronin1
1
Midwestern State University
*Award Eligible - Outstanding Master’s Student Podium Presentation
PURPOSE: Previous studies have examined the relationship lower-body strength
and power has with performance in events that require change of direction
(COD). However, there is a scarcity of investigations which have considered the
influence strength and power have on the magnitude of improvement in COD
performance as a result of training. Moreover, interventions selected within the
literature are often not representative of interventions used by strength and
conditioning professionals. Therefore, the purpose of this study was to investigate
the relationship between strength and power and the magnitude of improvement
in COD as a result of training. METHODS: Eleven collegiate athletes (age = 20.55
± 1.214 yr; height = 186.52 ± 6.569 cm; mass = 108.76 ± 17.433 kg) from a Division
II American football program participated in the study. Subjects were pre and
posttested in vertical jump (VJ), standing broad jump (SBJ), peak force (PF), time
to peak force (TPF), rate of force development (RFD), one-repetition maximum
back squat (1-RM BS), hexagon test, pro agility test, and T-test. Both absolute
values along with data normalized to body mass were used for purposes of
comparison. Subjects participated in an 8 week training program designed to
increase strength, power, and COD. Tests used to assess COD during pre and
posttesting were not used during the intervention. RESULTS: Pretest VJ power
showed strong correlation with both absolute change and percent improvement
in the T-test (r = -0.59 and -0.58, respectively). A strong correlation was also found
between the absolute change in SBJ and the absolute change in the hexagon
test (r = -0.51). Pretest Rel PF showed strong correlation with both pro-agility
and the T-test (r = -0.5 and -0.58, respectively). Pretest TPF and the hexagon
test showed strong correlation (r = -0.51) as did Rel 1-RM BS and the T-test (r =
-0.54). Posttest Rel PF revealed strong association with both the pro agility test
and the T-test (r = -0.61 and -0.81, respectively) and Rel 1-RM BS showed strong
correlation with performance in the T-test (r = -0.6). CONCLUSION: The findings of
this investigation suggest that an athlete’s ability to express strength and power
may influence subsequent adaptation to interventions designed to improve COD.
Moreover, adaptations in strength and power may also influence the magnitude
of improvement in COD tasks. PRACTICAL APPLICATION: Practitioners may wish
to consider sequencing their training to focus on strength and power early in the
athlete development process in order to enhance potential adaptations in COD later
on in training. In addition, when considering the addition of COD to the training
plan, it may be appropriate to maintain focus on increasing strength and power.
ACKNOWLEDGEMENTS: This investigation was partially funded by the Midwestern
State University Graduate School.
Friday, July 12, 2013, 10:45 AM - 11:00 AM
STRENGTH AS A PREDICTOR OF THE MAGNITUDE OF
ADAPTATION FROM POWER TRAINING
R. W. Brem1, J. B. Winchester1, F. A. Bourgeois1, F. B. Wyatt1, S. P. Cronin1
1
Midwestern State University
*Award Eligible - Outstanding Master’s Student Podium Presentation
Although previous research generated data that suggest stronger individuals
produce more power, the effects different strength levels have on the magnitude
of power adaptation have not been investigated thoroughly. PURPOSE: To
determine if strength levels can be used to predict the magnitude of adaptation
that may occur from participating in a training program designed to increase
power production. METHODS: The participants in this study were eleven men
[(mean ± SD):age 20.6 ± 1.2 years; height 186.5 ± 6.7 cm; mass 108.8 ± 19.1 kg] who
were NCAA Division II American football players. Pretest strength was assessed
during performance of an isometric mid-thigh pull (rate of force development
(RFD), peak force (PF), and time to peak force (TPF)) and via a one repetition
maximum back squat (1-RM BS). Lower body muscular power was tested using
the vertical jump (VJ) and standing broad jump (SBJ). Sprint performance
was assessed via timing gates in a 36.58 m (40 yard) dash. Correlations were
established between pretest strength variables and both absolute and relative
pre-post change in power tasks as well as sprint times and the kinetic variables of
peak velocity (PV) and acceleration derived from sprint performance. RESULTS:
Pretest RFD was significantly correlated with both absolute and percent change
of the 9.14 m (0 to 10 yard) sprint time (r = -0.86; r = -0.85), 18.29 m (0 to 20 yard)
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
sprint time (r = -0.72; r = -0.71), and 36.58 m (0 to 40 yard) sprint time (r = -0.61;
-0.62). The pretest 1-RM BS was significantly correlated with the absolute change
in VJ (r = 0.64) as well as relative improvement in VJ (r = 0.66). In addition, pretest
RFD showed significant correlation with both absolute and percent improvements
in acceleration (r = 0.84; r = 0.87). CONCLUSIONS: Pretest RFD correlated well
with the magnitude of improvement in sprint times as well as acceleration.
According to these data, pretest RFD was the most common statistically
significant predictor of the magnitude of improvement in sprinting. Moreover,
1-RM BS showed meaningful relationships with the magnitude of adaptation in
lower body power assessed via VJ. PRACTICAL APPLICATIONS: Practitioners may
wish to consider sequencing their training to focus on increasing strength early
in the athlete development process in order to enhance subsequent adaptations
in power. ACKNOWLEDGMENTS: This investigation was partially funded by the
Midwestern State University Graduate School.
Friday, July 12, 2013, 11:00 AM - 11:15 AM
SEGMENTAL CHANGES IN FAT AND SUBCUTANEOUS ADIPOSE TISSUE AFTER A
RAPID WEIGHT LOSS INTERVENTION IN WOMEN
J. Moon1, C. Tai1, P. Falcone1, L. Carson1, M. Kim1
1
MusclePharm Sports Science Center Research Institute
PURPOSE: Compare subcutaneous adipose tissue (SAT) and segmental fat loss
after a rapid weight loss intervention in healthy women. METHODS: Fourteen
women participated in the control group (28 +/- 4yr, 67.6 +/- 9.8kg, 167.5 +/- 7.5cm)
while twenty-three participated in the diet group (27 +/- 5yr, 69.0 +/- 10.5kg, 164.0
+/- 5.5cm). Control group subjects maintained their normal diet; experimental
subjects followed a strict 1200 calorie diet for twenty-one days. Regional and SAT
fat were collected pre- and post-testing using dual-energy X-ray absorptiometry
(DXA) and skinfold calipers (respectively). RESULTS: Significant (p < 0.05)
reductions in chest, mid-axilla, hip, thigh, subscapular, and triceps SAT thicknesses
were observed between pre- and post-testing for the experimental group only
(-0.75 to -3.25mm). Significant (p < 0.05) reductions were also observed for DXA
arms, legs, and trunk fat between pre- and post-testing for the experimental group
only (186.3 to 1,032.6 g). Reductions in mid-axilla, abdominal, hip, and thigh SAT
thicknesses were all correlated with DXA trunk fat (r 0.494 - 0.624). Reductions in
hip and thigh SAT thicknesses were correlated with DXA leg fat (r 0.449 - 0.479).
CONCLUSION: Both DXA and skinfold-based SAT measurements detected fat loss
after a rapid weight loss intervention in healthy women. Subcutaneous adipose
tissue measurements of the mid-axilla, abdominal, hip, and thigh appear to be
highly correlated with total segmental values measured by DXA. However, SAT
measurements of the chest, subscapular, and triceps may independently add to
DXA data. PRACTICAL APPLICATIONS: When tracking changes during a diet or
exercise intervention in women, valuable data can be obtained from both DXA and
SAT measurements independently. Practitioners and researchers should consider
SAT as well as segmental fat measurements when tracking body composition
changes in women as the exact location of fat stores that will be affected by diet
and exercise are unknown and vary by individual. ACKNOWLEDGEMENTS: This
investigation was supported by funding from MusclePharm Corporation.
Friday, July 12, 2013, 11:15 AM - 11:30 AM
THE RELATIONSHIP BETWEEN FUNCTIONAL MOVEMENT SCREEN SCORES AND
TEAM SPORT-SPECIFIC TESTS IN ATHLETES
R. G. Lockie1, A. B. Schultz1, C. A. Jordan1, S. P. Berry1, S. J. Callaghan1, M. D.
Jeffriess1, T. M. Luczo2
1
University of Newcastle / Exercise and Sport Science, 2California State
University Monterey Bay / Department of Kinesiology
The Functional Movement Screen (FMS) is comprised of 7 actions: deep squat
(DS), hurdle step (HS), in-line lunge (ILL), shoulder mobility, active straight-leg
raise (ASLR), trunk stability push-up (TSPU), and rotary stability. These actions
test how the body moves in a proximal-to-distal fashion. The FMS is often used to
diagnose movement deficiencies so as to prevent injury. Given that these screening
actions can be conceptualized in sprinting and jumping, the FMS may also detect
deficiencies in team sport-specific movements. PURPOSE: To determine the
relationship between individual FMS scores, as measured by the standard 21-point
and research-grade 100-point scales, and team sport-specific performance
(multidirectional speed, upper- and lower-body power, flexibility). METHODS: 41
team sport athletes (32 male, 9 female) were tested over 3 sessions. Subjects
were assessed in the FMS by 2 exercise scientists in the first session. The final 2
sessions involved team sport-specific tests of: flexibility (bilateral and unilateral
sit-and-reach [SAR]); linear (20-meter [m] sprint; 0-5, 0-10, 0-20 m intervals)
and change-of-direction speed (505 with turns off both feet; modified T-test with
initial movements to the left or right); and upper- (bilateral and unilateral medicine
ball chest pass [MBCP]) and lower-body (bilateral and unilateral vertical [VJ],
standing broad [SBJ], and lateral [LJ] jump; 5-bound test [5BT]) power. RESULTS:
Pearson’s correlation (r) analysis (p≤0.05) found relationships between the FMS
scores and athletic tests. A higher standard scale-scored DS related to faster 20-m
sprint (r=-0.321-0.351), right-foot turn 505 (r=-0.320), and right-turn T-test (r=0.367) performance. The DS, scored by both scales, positively correlated with
bilateral VJ and SBJ, left-leg SBJ, 5BT, and LJ off both legs (r=-0.317-0.519); and
MBCP (r=-0.317-0.427) performance. A higher standard and research-grade scale
for the left-leg ILL positively related with bilateral VJ and SBJ, and LJ for both
legs (r=-0.310-0.432). The TSPU positively correlated to the bilateral and unilateral
MBCP for both scales (r=0.347-0.547). The left-leg HS standard score related to
greater SAR (r=0.314-0.408); the research-grade score related to slower 505 times
(r=0.327-0.377), and greater SAR (r=0.344-0.393). The ASLR for both legs, scored
by both scales, related to slower 20-m sprint and 505 times (r=0.322-0.375),
poorer VJ (r=-0.311-0.349), and greater bilateral and unilateral SAR (r=0.3880.592). CONCLUSION: Selected FMS movements, scored by both the standard
and research-grade scales, related to performance in team sport athletes. This
was most noticeable for the DS, which correlated with multidirectional speed and
power. The ILL also related to leg power, while the TSPU provided an indication for
upper-body power as measured by the MBCP. These relationships were likely due
to similarities between movement mechanics and muscle recruitment. Greater leg
flexibility, as measured by the HS and ASLR, related to poorer speed and power.
Leg stiffness may be more beneficial for team sport athletes, and a field screen
of this should be developed. PRACTICAL APPLICATIONS: Individual FMS actions
do relate to team sport-specific performance. The DS, ILL, and TSPU can be used
to monitor physical deficiencies that could affect speed and power. The standard
scale seems to provide sufficient information to detect movement deficiencies
that could affect team sport performance.
Friday, July 12, 2013, 11:30 AM - 1:00 PM
Poster: 2
COMPARISON OF EXERCISE METABOLISMS BETWEEN ATHLETES
AND RECREATIONALLY ACTIVE INDIVIDUALS AT THE POINT OF
EQUIVALENCE OF CHANGE
G. Gallien1, D. Bellar2, L. Judge3
1
University of Louisiana at Lafayette, Lafayette, La, 2University of Louisiana at
Lafayette, 3Ball State University, Muncie, IN
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
PURPOSE: The current study assessed and compared the number of METs at
the Point of Equivalence of Change (PEC) between athletes and recreationally
active individuals. PEC is the point at which ΔCO2 production first matches ΔO2
consumption. It was determined by measuring VCO2 and VO2 during a graded
exercise test and finding the first point where the two were matched in change
per unit time (ΔVCO2/ΔVO2=1). METHOD: Sixteen NCAA Division 1 Track and
Field Athletes and fourteen active college aged students participated in a graded
exercise test to determine their VO2max. The PEC is determined through the 3rd
order polynomial regression of VCO2 and VO2 followed by solving the derivative
of this function for a slope of 1. At the PEC, the relative oxygen consumption was
converted to METs then compared. RESULTS: A One-Way Analysis of Variance
(ANOVA) was used to compare METs at the PEC between groups. There was
significant difference between the MET values of the athletes compared to the
MET values of the recreationally active (F=7.384, p=0.011). The athletes had a
mean MET at the PEC of 9.09 +/- 2.21 as compared to the recreationally active
participants having a mean MET of 6.83 +/- 2.34. CONCLUSION: These data suggest
that the athletes had significantly elevated metabolisms at the PEC compared
to recreationally active individuals. PRACTICAL APPLICATION: Athletic trainers
and conditioning coaches should be aware of the differences that exist between
exercise metabolisms for athletes and recreationally active individuals. When
prescribing moderate intensity exercise for an athletic population, professionals
must be conscious of the athletes’ elevated metabolisms during exercise levels
that correspond with the PEC, which occurs at a sub-maximal intensity.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 3
PERSONALITY TRAITS OF ULTRA-ENDURANCE, ULTRA-DEMAND ATHLETES
J. D. Lindfors1, T. J. Piper1, C. S. McMillan1
1
Western Illinois University, Department of Kinesiology,
Major of Exercise Science
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
The field of Exercise Science, in its continuous expansion, consequently has
resulted in new populations of athletes, for which little to no data currently
exists. This research begins to investigate a previously unexplored population of
athletes known for engaging in high intensity, long duration forms of exercise.
PURPOSE: To explore the personality traits of athletes who choose to participate
in ultra-endurance events, uniquely characterized by bouts of high intensity, long
duration physical activity. Fifteen participants (male=13, female=2, mean age=
30.7±9.36yrs, age range=20-47) enrolled in a 36-hour event were surveyed using
the Jung Typology Personality test. Prior frequency of training leading up to the
race just over 2.5 days per week (M=2.67±0.89) with a range of average training
sessions from (30-60 min) to (120 min). Participants’ longest average duration
of training session in preparation for the race exceeding 500 minutes in total
(M=516.67 ± 477.47min) with scores ranging from 90 minutes to 1800 minutes.
Participants’ education level ranged from High School to Bachelor’s Degree; mean
falling between an Associates and Bachelor’s Degree. Answers were analyzed and
each participant’s survey was assigned a 4-letter type designation of personality
based upon the work of Carl Jung’s and Isabel Briggs Myers’ typology. RESULTS:
The results of the traits exhibited by the sample of participants within this study
shows two areas of high tendency; Intuition and Judgment, as they relate to the
descriptions of trait factors of Carl Jung’s Trait Typology Test. CONCLUSIONS:
From the results of the 4-letter type designated to each participant, differences in
trait dimension average are demonstrated clearly in to specific areas; Intuition and
Judging. Also demonstrated are moderate distributions toward Thinking, within
the Thinking-Feeling dimension. Slight differences are seen towards Extraversion
within the Extraversion-Introversion dimension. The trait dimension of Perceiving
was not demonstrated by any of the participants. PRACTICAL APPLICATIONS: This
research was conducted for the purpose of gaining insight into a population of
athletes that has little to no data collected upon. The results can act as a guide for
future research to be conducted, specifically what areas to be aware of in regard to
these athlete’s traits. By identifying these and other factors within personality that
possibly contribute to participation in such strenuous and demanding exercise,
this population can be better understood as well as quantified scientifically. Poster: 4
METABOLIC, CARDIOVASCULAR, AND PERCEPTUAL RESPONSES TO A
THERMOGENIC NUTRITIONAL SUPPLEMENT AT REST, DURING EXERCISE,
AND RECOVERY IN MEN
H. C. Bergstrom1, T. J. Housh1, D. A. Traylor1, R. W. Lewis Jr.1, K. C. Cochrane1,
N. D. Jenkins1, R. J. Schmidt1, J. T. Cramer1, G. O. Johnson1, D. J. Housh2
1
University of Nebraska-Lincoln, 2University of Nebraska Medical Center
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: This study examined the acute metabolic, cardiovascular, and
perceptual responses to a thermogenic nutritional supplement at rest, during
low-intensity exercise, and recovery from exercise in men. METHODS: Twenty-one
recreationally active men (mean ± SD; age = 23.5 ± 2.6 years; height =181.3 ± 6.1
cm; weight = 85.5 ± 10.5 kg; body mass index = 26.0 ± 2.4) were recruited for this
randomized, double-blinded, placebo-controlled, crossover study. The nutritional
supplement capsules included 200 mg caffeine, 100 mg capsicum extract, 2 mg
piperine, 250 mg boswellia serrate extract, 500 mg dried ginger root, 100 mg
cinnamon bark, 20 mg niacin, and 500 mg macuna pruriens. The placebo capsules
were matched in size and appearance and contained microcrystalline cellulose.
Each testing session consisted of four phases: 1) 30 min of initial resting measures,
followed by ingestion of the placebo or thermogenic nutritional supplement; 2)
50 min of post-supplementation resting; 3) 60 min of treadmill walking (3.2 –
4.8 km·hr-1); and 4) 50 min of post-exercise resting. Energy expenditure (EE),
oxygen consumption rate (VO2), respiratory exchange ratio (RER), and heart
rate (HR) were recorded during all four phases and reported as 10 min averages.
During exercise, the rating of perceived exertion (RPE) was recorded every 15
min. Statistical analyses included separate 2-way repeated-measures ANOVAs
(condition x time), 1-way repeated-measures ANOVAs, and paired t-tests (p <
0.05). RESULTS: There were no significant differences for any of the measures
between the supplement and placebo during the initial 30 min resting or the 50
min post-supplementation time periods. During exercise, VO2 was 3 to 4% greater
for the supplement than the placebo at each 10 min average. In addition, EE was
3 to 4% greater and RER was 2 to 3% less for the supplement than the placebo
from 20 to 60 min. There were, however, no differences in HR or RPE between
the supplement and placebo during exercise. Post-exercise, VO2 was 6% greater
at 10 and 20 min and 5% greater at 50 min, EE was 10% greater at 10 and 20
min, HR was 4 to 5% greater at 20 and 30 min, and RER was 4 to 6% less from
30 to 50 min for the supplement than the placebo. CONCLUSIONS: The greater
EE and VO2 values for the supplement than placebo during exercise and postexercise resting indicated that the thermogenic nutritional supplement used in
the present study increased the metabolic rate. In addition, the lower RER for the
supplement than placebo suggested a shift in substrate utilization and a greater
reliance on lipid metabolism. Furthermore, there were minimal changes in HR and
the supplement had no effect on RPE. PRACTICAL APPLICATIONS: These findings
suggested that the specific blend of ingredients in the thermogenic nutritional
supplement, when combined with exercise, may increase the metabolic rate with
minimal changes in cardiovascular function and no effect on the perception of
effort. Thus, it is possible that the thermogenic supplement used in this study
would help dieters achieve a negative caloric balance, increase weight loss, and
improve body composition when combined with long duration, low intensity
exercise. ACKNOWLEDGEMENTS: This study was supported by a clinical trial
grant from General Nutrition Corporation.
Poster: 5
THE EFFECT OF INTERMITTENT TORSO COOLING ON THERMOREGULATION
AND PERCEIVED RECOVERY IN BASEBALL CATCHERS
S. H. Bishop1, R. L. Herron2, C. Katica2, G. Ryan3, P. Bishop2
1
Texas A&M University-Commerce, 2University of Alabama,
3
University of Montana Western
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: A baseball catcher may have to catch in a hot environment for up to
27 innings over the course of a three-game series. Cryotherapy has been shown
to reduce heat and cardiovascular strain during activity in the heat. This study
investigated the effects of intermittent cooling of the torso on core temperature
(Tre) and subjective measures of recovery and exertion during a simulated
catching performance. METHODS: Trained college-aged male baseball catchers
(n = 6) performed simulated catching in a controlled, hot environment (35 °C, 25%
relative humidity). Two series of 3-simulated games were used to evaluate heat
strain on thermoregulation and mental acuity in baseball catchers; one series with
torso cooling (VC) and one with no cooling (NC). Rectal temperature (Tre), heart
rates (HR), perceived exertion (RPE), recovery (PRS) were recorded. RESULTS: A
significantly smaller (p = < 0.01) mean Tre change was seen in VC (0.58 ± 0.2 °C)
when compared to NC (0.98 ± 0.2 °C). RPE was significantly lower and PRS was
significantly improved for VC compared to NC (both p ≤ 0.05). Mean recovery HR
during VC was significantly lower than NC in the 5th (VC = 84 ± 8 bpm, NC = 90 ± 9
bpm, p = 0.04), 7th (VC= 84 ± 3 bpm, NC = 92 ± 7 bpm, p = 0.02), and 9th (VC = 85
± 7 bpm, NC = 93 ± 5 bpm, p = 0.01) innings. HR during catching was significantly
lower at the end of the VC trials when compared to NC (108 ± 16 bpm versus 120 ±
19 bpm, p = 0.02). CONCLUSION: VC alleviated heat strain, cardiovascular strain,
and facilitated perceived recovery in catchers over a simulated three game series
performed in hot conditions. Poster: 6
DOES INGESTING A SODIUM-SODIUM CITRATE BEVERAGE EFFECT HR, VO2,
RER, & BLOOD LACTATE IN PREVIOUSLY HYPOHYDRATED SOCCER ATHLETES
IN A HOT ENVIRONMENT DURING AEROBIC EXERCISE?
J. G. Carter1, K. A. Brooks2, J. Dawes2
1
Texas A&M University, 2Texas A&M University Corpus Christi
*Award Eligible - Outstanding Doctoral Student Poster Presentation
INTRODUCTION: Research has shown that many athletes are continually in a state
of dehydration. This impairs performance, and increases the chance of heat illness
occurring. Numerous athletes have experienced some degree of heat illness,
resulting in acute discomfort and distortion of their physiological mechanisms.
One method that has proven effective in rehydrating athletes is use of a beverage
containing sodium to increase fluid absorption and stimulate the thirst mechanism.
PURPOSE: The purpose of this study was to determine if ingesting a beverage
containing 1,780 mg of sodium and 2,953 mg of sodium citrate would effect HR,
VO2, RER, and blood lactate for previously hypohydrated individuals in a heated
environment during aerobic exercise. METHODS: Five division one female soccer
athletes participated in the study. The subjects had the following descriptive
statistics: Age 19 ± 0.7 yr, Height 162.3 ± 4.6 cm, Weight 63.2 ± 8.1 kg, %BF 23.68
± 9.2%, and VO2max 60.2 ± 5.1 ml∙kg-1∙min-1. The study required subjects (N=5) to
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
run the experimental protocol twice. Fluid intake was matched for each condition.
Prior to running to exhaustion at 70% of their VO2max on a treadmill in a heated
chamber, the subjects were passively dehydrated and loss 2.5% of their body
mass. The subjects were given 2 hours to rehydrate via either a placebo (10 mmol
Na+∙L-1) or the supplement (164 mmol Na+∙L-1). After medical clearance, subjects
performed a graded exercise test to determine VO2max. ACSM equations were used
to determine running speed at 70% of VO2max. Testing conditions consisted of the
subjects running at 70% of their VO2max until exhaustion while in a heated chamber
at 90° Fahrenheit. The study employed a double-blind, repeated measure, within
subject protocol. The treadmill protocol consisted of a five minute warm-up (3
minutes at 40% of their VO2max and 2 minutes at 55% of their VO2max), running
to exhaustion at 70% of VO2max, and a 10 minute cool down at 3.0 mph. Every
five minutes on the treadmill, variables were assessed. RESULTS: Results for
variables at 70% of maximal VO2 indicated there were no significant differences
observed between conditions pre and post exercise. There were no significant
differences between conditions for variables at the start or end of the run, and at
each 5 minute data collection point throughout the run, there was no significant
difference between conditions for BLA and VO2. There were no significant
differences between conditions for heart rate until the 30 minute mark. At the
30, 35, and 40 minute marks, there was a significant difference in HR (p<0.05),
with the supplement trial reporting lower heart rates at each mark. CONCLUSION:
Heart rate was lower when hydrated with the sodium supplemented beverage
after sustained aerobic exercise at 70% of VO2max, in a hot environment. The ability
to maintain a lower heart rate may lead to increased performance through a
decreased effect of cardiovascular drift. Notably, all of the subjects performed
better on the first treadmill session regardless of the experimental condition (i.e.
placebo or high sodium solution). Absolute conclusions cannot be drawn from
this study. PRACTICAL APPLICATION: Dehydration should be a major concern for
any athlete, especially for those who are performing in hot, humid environments.
Preventative methods such as ingesting a sodium solution, frequent weigh-ins,
and continual education for the athlete should all be employed to avoid any form
of heat illness to the athlete. Practitioners should be aware of the importance
of aerobic conditioning for an athlete while exercising in a hot environment.
Knowledge of warning signs and symptoms, and taking proper precautions to
prevent complications is of importance. Coaches should be aware that athletes
who are less conditioned are at higher risk for heat illnesses; therefore, proper
training and steps towards acclimatization must be employed prior to training in
the heat.
Poster: 7
THE EFFECTS OF A PERSONAL OXYGEN SUPPLEMENT DURING VIGOROUS
EXERCISE ON RESPIRATORY RESPONSES AND PERFORMANCE
APPLICATIONS: Athletes, coaches, as well as recreational exercisers should be
aware that personal, supplemental oxygen does not appear to be an effective
ergogenic aid. ACKNOWLEDGEMENTS: The authors would like to acknowledge
the support of Second Wind LLC during the course of this project.
Poster: 8
EFFECTS OF 8 WEEKS OF XPAND 2X PRE WORKOUT SUPPLEMENTATION
ON SKELETAL MUSCLE HYPERTROPHY, AND LOWER BODY STRENGTH IN
RESISTANCE TRAINED MALES
J. E. Dudeck1, N. S. Munnelly1, R. P. Lowery1, J. M. Joy1, E. Oliveira de Souza2,
M. A. Naimo1, S. Wells3, R. Wildman3, S. A. McCleary1, E. Max1,
N. Carpenter1, J. M. Wilson1
1
University of Tampa Human Performance Lab, 2Laboratory of Neuromuscular
Adaptations to Strength Training, School of Physical Education and Sport,
University of São Paulo, 3Dymatize Enterprises, LLC. Farmers Branch, Texas
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
PURPOSE: Dymatize® XPAND 2X is a proprietary blend comprised of branched
chain amino acids, creatine monohydrate, beta-alanine (CarnoSyn®), quercetin,
coenzymated B-vitamins, alanyl-glutamine (Sustamine®), and natural nitrate
sources from pomegranate and beet root extractspurported to enhance
neuromuscular adaptations. However to date, no long-term studies have been
conducted with this supplement. The purpose of this study was to investigate
the effects of XPAND 2X on skeletal muscle hypertrophy and lower body strength
in resistance trained males. METHODS: Twenty resistance-trained males (21.3 ±
1.9 years) were randomly assigned to consume XPAND 2X or a placebo of equal
weight and volume (food-grade orange flavors and sweeteners) in a double-blind
manner, 30 minutes prior to exercise. All subjects participated in an 8-week, 3-day
per week, periodized, resistance training that was split-focused on multi-joint
movements such as leg press, bench press, and bent-over rows. Ultrasonography
measured muscle thickness of the quadriceps femoris , and strength of the leg
press were determined at weeks 0, 4, and 8 of the study. Data were analyzed with
a 2x 3 repeated measures ANOVA with LSD post hoc tests utilized to determine
where differences occurred. RESULTS: There was a significant group-by-time
interaction in which XPAND 2X supplementation resulted in a significant (p <
0.05) increase in strength of the bench press (18.4% vs. 9.6%) compared with
placebo after 8 weeks of training. XPAND 2X supplementation also resulted in
a significant increase in quadriceps muscle thickness (11.8 % vs. 4.5 %) compared
with placebo (group*time, p <0.05). CONCLUSIONS: These results suggest that
XPAND 2X supplementation can augment adaptations in strength, and skeletal
muscle hypertrophy in resistance-trained individuals. E. Cory1, D. Bellar2, L. Judge3
Poster: 9
University of Louisiana at Lafayette, Lafayette, La,
2
University of Louisiana at Lafayette, 3Ball State University, Muncie, IN
RICE PROTEIN INCREASES LEAN BODY MASS, MUSCLE HYPERTROPHY,
POWER AND STRENGTH COMPARABLE TO WHEY PROTEIN
FOLLOWING RESISTANCE EXERCISE
1
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Personal oxygen supplements are becoming more prevalent in the ergogenic
market. The effectiveness of such products has yet to be determined. PURPOSE:
The purpose of this investigation was to examine the effects a personal 90% oxygen
supplement had on a participant’s physiological responses and performance after
use during a horizontal run at 80% of VO2Max. METHODS: The participants for this
blind, placebo controlled experiment were college students ages 20 to 28, with a
total of 11 females and 7 males tested (n=18). Participants first underwent a VO2Max
assessment (45.8 ± 8.4mlO2/kg*min). Participants then ran two separate trials
at 80% of their previously established VO2max to exhaustion. Participants were
randomly assigned an order of treatment (placebo -compressed air, or oxygen
supplement) that was dosed every 5 minutes during the two runs to exhaustion.
RESULTS: Performance between treatments was evaluated via a paired-samples
T-test and was not found to be different (t=1.059, p=0.305). Mean times were
1128.44 seconds ± 613.12 for the oxygen trials, and 1051.27 seconds ± 449.36 for the
placebo trials. Repeated measures Anovas were used to assess the relationship
between treatments for respiratory data. Minute Ventilation (Ve L/min) data
points were collected for 50 seconds after supplementation for both oxygen
and placebo trials, and the main effects of treatment proved to be insignificant
(F=0.120, p=0.734). The analysis similarly did not reveal any significant
treatment*time interaction (F=0.819. p=0.518). Similar data points for VCO2 (L
O2/min) were also analyzed, and the main effects of treatment (F=0.111, p=0.744)
and the interaction effect for treatment*time (F=0.647, p=0.651) were, again,
insignificant. CONCLUSION: The results of the study suggest that the introduction
of an oxygen supplement into the airway during vigorous exercise has no effect
on performance, was isocapnic with a placebo condition, and did not affect
ventilation even at the time directly surrounding the application. PRACTICAL
S. I. Weiner1, J. M. Joy1, R. P. Lowery1, R. Jaeger2, M. Purpura2, E. Oliveira de
Souza3, J. E. Dudeck1, N. Carpenter1, E. Max1, D. Brockunier1, J. M. Wilson1
1
University of Tampa Human Performance Lab, 2Increnovo LLC, 2138 E
Lafayette Pl, Milwaukee, WI 53202, 3Laboratory of Neuromuscular Adaptations
to Strength Training, School of Physical Education and Sport,
University of São Paulo
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Purpose: Consumption of moderate amounts of animal-derived protein has
been shown to differently influence hypertrophy during resistance training when
compared with isonitrogenous and isoenergetic amounts of plant-based protein.
Objective: We aimed to determine if high doses of rice protein isolate could
increase recovery and elicit adequate changes in body composition compared
to whey protein isolate if given following periodized resistance-training. Method:
24 college-aged, resistance trained males were recruited for this study. Subjects
were randomly and equally divided into two groups, either consuming 48g of rice
or whey protein isolate on training days. Subjects trained 3 days per week for 8
weeks as a part of a daily undulating periodized resistance-training program. The
rice and whey protein supplements were isocaloric and isonitrogenous, and they
were consumed immediately following exercise. Ratings of perceived recovery,
soreness, and readiness to train were recorded prior to and following the first
training session. Ultrasonography determined muscle thickness, dual emission
x-ray absorptiometry, and bench press and leg press strength were recorded
during weeks 0, 4, and 8. Results: No detectable differences were present
in psychological scores of perceived recovery, soreness, or readiness to train
(p>0.05). Significant time effects were observed in which lean body mass, muscle
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
mass, strength and power all increased and fat mass decreased; however, no
condition by time interactions were observed (p>0.05). Conclusion: Rice protein
isolate administration post resistance exercise decreases fat-mass and increases
lean body mass, skeletal muscle hypertrophy, power and strength comparable to
whey protein isolate.
Poster: 10
ELECTROMYOGRAPHIC ACTIVATION OF SUPERFICIAL MUSCULATURE DURING
A SUSPENSION INVERTED ROW AS COMPARED TO AN INVERTED ROW
R. Brannan1, R. Snarr2, E. Witte1, C. Jenkins1, M. Esco3
1
Auburn University at Montgomery, 2Auburn University Montgomery,
3
Auburn University Montgomery
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Stability, balance and coordination are all important factors when training for
specificity or mimicking activities of daily living. Suspension training is a newer
form of instability training that can provide a way to perform typical resistance
exercises in an unstable environment. Research in stability training has mainly
focused on the effects of an unbalanced surface and core musculature activation. Very few studies have focused on the primary and secondary musculature
targeted during specific pulling exercises. Therefore, movements such as the
inverted row have a need to be examined when an instability device is introduced
to this exercise. PURPOSE: The purpose of this investigation is to quantify the
differences in muscular activation during a suspension inverted row [SIR] and a
traditional inverted row [IR] across selected superficial musculature (latissimus
dorsi (LD), posterior deltoid (PD), middle trapezius (MT), and biceps brachii (BB)). METHODS: Fifteen men (n = 12) and women (n=3) volunteered to participate in this
study. Subjects were asked to perform four repetitions of both the inverted row
(IR) and suspension inverted row (SIR). For this study, the order of the exercises
was randomized. Mean peak EMG values were recorded for each muscle group
during all exercises performed. RESULTS: The SIR provided the following values:
MT = 2.8496 ± 1.54681, PD = 3.5490 ± 1.61145, LD = 3.9143 ± 2.33725, BB = 3.9482 ±
1.28421. IR values were: MT = 3.0558 ± 1.89448, PD = 3.4137 ± 1.38606, LD = 3.7352
± 2.14528, BB = 4.4814 ± 1.44295. CONCLUSION: This study found no significant
differences between MT, LD, and PD activation between the two exercises (p >
0.05). However, IR elicited a significantly greater BB activation compared to SIR
(p < 0.05). PRACTICAL APPLICATIONS: Practitioners should take note that the
suspension and traditional inverted row provide similar activation levels, except
for the BB. Therefore, suspension training can provide a substitution for the
traditional inverted row when necessary. However, further research is warranted
to determine the affects of suspension training on additional exercises with a
strong focus on primary and secondary movers. Poster: 11
ELASTIC BANDS AS A COMPONENT OF PERIODIZED RESISTANCE TRAINING
N. Carpenter1, E. Max1, J. M. Wilson1, R. P. Lowery1, J. M. Joy1, J. E. Dudeck1
1
University of Tampa Human Performance Lab
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Purpose: Variable resistance (VR) training has recently become a more
prevalent component of strength and conditioning programs. Prior research has
demonstrated increases in power and/or strength using low loads of VR. Typically,
researchers have not practically applied VR; wherein, the VR is applied during
every session when this may not be the case in a real world setting. However,
no study has examined using high loads of VR as a part of a periodized training
protocol. Prior research has also compensated traditional load to account for the
increased load the VR provides. Therefore, our purpose is to examine VR training
within the context of a periodized training program, and to examine a greater
load of VR than has been examined in prior research without compensating for
the additional load the VR applies. Methods: 14 NCAA Division II male basketball
players (91.8 ± 13.2 kg, 191.4 ± 12.5 cm) were recruited for this study. Athletes
were divided equally into either a VR or control group based upon 1-repetitionmaximum (1-RM) strength. Participants underwent identical training protocols;
however, the VR group added 30% of their 1-RM as band tension to their prescribed
weight on the squat and bench press for one session per week. Thirty percent
was calculated with the bands at their longest length, and at the zero-velocity
point of the movement, the bands provided little to no tension. Rate of power
development (RPD), peak power, and vertical jump height were measured on a
force platform. Strength in the squat, bench press, and deadlift were measured as
1RM strength. Body composition was measured via DXA, and vertical jump height
was measured a second time with a vertec. Measurements were recorded pre and
post treatment. Results: No baseline differences were observed between groups
for any measurement of strength, power, or body composition. A significant
group by time interaction was observed for RPD, in which RPD was greater in VR
training group post training than in the control group. Significant time effects
were observed for all other variables including squat 1-RM, bench press 1-RM,
deadlift 1-RM, vertical jump, and lean mass. While there were no significant group
X time interactions, the VR training group’s percent changes and ESs indicate a
larger treatment effect in the squat and bench press 1RM values and the vertical
jump performed on the force plate and vertec. Conclusions: These results
suggest that when using VR as a component of a periodized training program,
power and strength can be enhanced. Therefore, athletes whom add VR to one
training session per week may enhance their athletic performance. Furthermore
for strength and power oriented athletes or practitioners, it is conceivable that VR
training can be applied in order to overcome a stagnation of progress and break
plateaus.
Poster: 12
THE EFFECTS OF TWO DIFFERENT TRAINING INTENSITY PROTOCOLS
USING THE FREE WEIGHT SQUAT ON MAXIMAL AND RAPID TORQUE
CHARACTERISTICS OF THE LEG EXTENSORS
E. C. Conchola1, R. Thiele1, B. J. Thompson2, G. Hester1, M. Wood1, M. Hawkey1, T.
B. Palmer1, D. B. Smith1
1
Oklahoma State University, 2Texas Tech University
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Training intensity protocols often vary in regards to a specific purpose and
function where either high loads/slow velocity (HL) or lighter loads/high velocity
(explosive power; EP) training paradigms are incorporated to elicit either more
strength or power training specific adaptations, respectively. However, we are
aware of no previous studies that have investigated and compared the effects
of HL and EP training protocols on maximal and rapid torque characteristics
of the leg extensors. PURPOSE: The purpose of this study was to examine the
effects of two different training intensity protocols using the free weight squat
on maximal and rapid torque characteristics of the leg extensors at immediately
following and during a 30 min post training recovery period. METHODS: Ten males
(mean±SD: age=22.33±3.12 years) participated in a familiarization trial followed
by two squat testing sessions separated by seven days. Subjects were randomly
assigned to either a 5 × 8 (5 sets of 8 repetitions at 80% of 1-RM; HL), or 5 × 16
(5 sets of 16 repetitions at 40% 1-RM; EP) free weight squat training protocol.
All repetitions were performed at a standardized cadence (regulated by a
metronome) of two seconds eccentric and either a two second (HL) or explosively
as possible (EP) concentric phase. Maximal and rapid torque variables were
assessed on an isokinetic dynamometer with the leg angle set at 60° below the
horizontal plane of the right leg. Participants performed two maximal voluntary
contractions (MVCs) before (Pre) and at immediately post (Post), seven (recov7),
fifteen (recov15) and thirty (recov30) minutes following the completion of the
squat protocols. Isometric Peak Torque (PT) was determined as the highest 0.5
s epoch during the entire 3-4 s MVC. Rate of Torque Development (RTD) was
determined from the linear slope of the torque-time curve at early (30 and 50ms),
and late (100-200ms) time intervals, respectively. A two-way mixed factorial
ANOVA (intensity [HL vs. EP] x time [pre vs. post vs. Recov 7 vs. Recov 15 vs.
Recov 30]) was used to analyze all PT and RTD variables. RESULTS: For PT,there
was a significant interaction for intensity × time (P=0.044) where the PT for the
HL was lower (P=0.01) at immediately post compared to baseline, but recovered
by Recov7 (P=0.14); but PT for EP was not different at any of the post training
time periods (P=0.551–1.000). For RTD30, RTD50 and RTD100_200 there were
no interactions (P=0.18-0.65) but there were main effects for time for RTD30,
RTD50 and RTD100-200 (P=0.0001-0.002). All RTD variables were lower at
immediately post (P=0.003–0.010) compared to Pre, however, RTD50 was also
significantly lower at Recov15 (P=0.015) and Recov30 (P=0.001). CONCLUSIONS:
These findings suggest a high intensity (80% 1-RM) compared to a lighter
intensity (40% 1-RM) squat protocol elicited greater declines in PT, however, rapid
torque characteristics were significantly and similarly affected by both training
intensity protocols. PRACTICAL APPLICATIONS: These findings may be useful for
practitioners and coaches when designing training protocols, as these findings
demonstrated that HL and EP protocols may have differential effects on PT, but
both training protocols can affect rapid torque characteristics for an extended
period of time post training. The resulting decline in rapid torque characteristics
may have adverse functional, performance-based, and injury risk implications in a
variety of populations and settings.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 13
EFFECT OF HIP INTERNAL ROTATION TRAINING ON RANGE OF MOTION AND
PERFORMANCE VARIABLES IN MALE COLLEGIATE GOLFERS
T. Donahue1, D. Szymanski1, B. Stover1, A. Elumalai1, J. Parks1
1
Louisiana Tech University
*Award Eligible - Outstanding Master’s Student Poster Presentation
Previous golf research has reported that increases in the range of motion (ROM)
of the shoulders and hips (focused on internal and external rotation) as well as
the torso has increased golf club head speed (CHS) and exit-ball velocity (EBV),
ultimately increasing carry distance (CD) of the golf ball. PURPOSE: To determine
if 8 weeks of hip internal rotation training can increase ROM in the hips, shoulders,
and torso in the standing and sport-specific positions. A second purpose was
to determine if hip internal rotation training could improve the golf performance
variables of CHS, EBV, and CD. METHODS: Twelve NCAA Division I male golfers
competing during the fall season volunteered for this experiment. All subjects
signed an informed consent form according to the university’s Institutional Review
Board. Subjects had a mean age, height, and body mass of 20.2 ± 1.5 yr, 179.6 ±
7.2 cm, and 77.4 ± 12.0 kg. Subjects underwent a battery of static and passive
ROM testing (seated and supine internal and external rotation of the hip, seated
internal and external rotation of the shoulder, and right and left torso rotation
standing and in the sport-specific golf stance) in addition to having the golf
performance variables of driver CHS, EBV, and CD measured using the TrackMan
(Brighton, MI, USA). TrackMan is a radar unit that measures both club delivery
and the full trajectory of the golf shot. Subjects took 5 swings with their driver and
mean values were recorded for CHS, EBV, and CD. Range of motion testing was
performed using a Baseline Absolute Axis 360° Digital Goniometer (Fabrication
Enterprises, Inc.,White Plains, NY, USA) and trunk ROM (standing and sportspecific stance) were measured using a mat with markings placed at intervals of
5°. After pre-testing, subjects were divided into 2 equal groups (treatment = 6
and control = 6). The treatment group used the hip internal rotation devices twice
a day, 30 sec per session (3 x 10 sec) for each leg, 5 days a week for 8 weeks (total
of 80 sessions) while the control did not. All other training was the same for
both groups. After 8 weeks of training, the same tests were completed by both
groups. RESULTS: A 2-way analysis of variance (ANOVA) with repeated measures
was used to determine any pre- and post-training differences. A statistically
significant difference (p < 0.05) was found between groups post-training in the
passive supine hip internal rotation on both the left and right leg as well as in the
shoulder internal rotation of the left arm for the treatment group. CONCLUSION: Results suggest that using the hip internal rotation devices 2 times per day, 5
times per week for 8 weeks can improve internal rotation of the hips and shoulder;
however, there were no improvements in any of the golf performance variables.
PRACTICAL APPLICATION: Practitioners that are looking to improve internal
rotation of the hips and shoulders can use the hip internal rotation device. Further
research is needed with a greater sample size to evaluate the effectiveness of
the hip internal rotation device on making improvements in golf performance
variables. ACKNOWLEDGEMENTS: We would like to thank CEU Now LLC for
partially funding this study.
Poster: 14
EFFECT OF RESISTANCE TRAINING ON HYPERTROPHY IN DIFFERENT MUSCLE
PORTIONS
M. Drummond1, L. Szmuchrowski2, A. Mol2, R. Angelo2, B. Couto3
1
Federal University of Minas Gerais, Brazil. FUMEC University, Brazil, 2Federal
University of Minas Gerais, Brazil, 3Federal University of Minas Gerais
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: The purpose of this study was to investigate the chronic effects of
resistance training (RT) on muscle hypertrophy in different portions of the elbow
flexors muscles. METHOD: The sample included 10 untrained male volunteers
(age 22.1±2.72yr, mass 72.6 ± 11.4kg, stature 1.74±0.07m) who initially underwent
a Magnetic Resonance Image (MRI) scan to determine the cross-sectional area
(CSA) of the elbow flexors. In the MRI were obtained 30 axial slices, between
the proximal and distal point of the right arm, on craniocaudal axis. The proximal
CSA muscle portion was obtained by the mean of the slices number four, five
and six. The medial CSA muscle portion was obtained by the mean of the slices
15, 16 e 17 and distal CSA muscle portion by the mean of slices 25, 26, 27 slices.
The volunteers subsequently performed RT of the elbow flexors for 12 weeks. The
RT protocol included the performance of 4 sets of 8 to 10 repetition maximums
of unilateral elbow flexion exercise (right arm) on a Scott-type bench. The rest
intervals between sets were 120 seconds, and 3 training sessions were performed
each week. After 12 weeks of training a MRI was again performed to determine
the proximal, medial and distal CSA of the elbow flexors muscles in right arm.
RESULTS: The volunteers exhibited an increase in CSA in all muscle portions
examined. The increase in the proximal CSA was 16.6±5.8%, 19.3±4.8% in medial
CSA and 17.2±5.3% in distal CSA. There were no significant differences in muscle
hypertrophy between all muscle portions examined (p=0.254, p=0.190, p=0.321).
CONCLUSION: The muscle hypertrophy due to RT is similar in all portions of the
elbow flexors muscles in untrained subjects. PRATICAL APLICATION: According
to the results, the RT does not determine different hypertrophy between portions
of the elbow flexors muscles in untrained subjects. Thus, it is not indicate the
RT for such purpose for untrained subjects. ACKNOWLEDGEMENTS: The authors
are grateful to “Pró-reitoria de Pesquisa” of Federal University of Minas Gerais,
“Fundação de Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG” and
to AXIAL - Medicina Diagnóstica [Diagnostic Medicine] of Belo Horizonte, Minas
Gerais, Brazil.
Poster: 15
EFFECTS OF TRADITIONAL RESISTANCE EXERCISE VS. BODY WEIGHT
RESISTANCE EXERCISE ON THE HORMONAL RESPONSE IN YOUNG RESISTANCE
TRAINED MALES
J. Holt1, S. Hayward1, J. Outlaw1, B. Burks2, M. Stone2, B. Stai2, E. Faillace2,
B. Cox2, A. E. Smith-Ryan3, S. W. Urbina2, C. Wilborn2, L. W. Taylor2
1
Univ of Mary Hardin-Baylor, 2Univ of Mary Hardin-Baylor/Human Performance
Laboratory, 3University of North Carolina Chapel Hill
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
PURPOSE: There are various physical fitness programs which incorporate strength,
power, speed, coordination, and endurance components to promote physiological
muscle adaptations. The acute physiological and hormonal changes associated
with these programs have not been defined by research to see if they result in
adaptations. The purpose of this study was to evaluate the acute physiological
response of a body weight resistance exercise protocol as compared to a traditional
bout of resistance exercise. METHODS: Eleven resistance trained males (21.18 ±
1.22 yrs, 85.23 ± 13.2 kg, 174.3 ± 14.5 cm, 14.8 ± 5.9 %BF) participated in the acute
resistance exercise study using a randomized cross-over design. Subjects engaged
in either an body weight resistance exercise workout including as many rounds as
possible (AMRAP) of 5 pull-ups, 10 pushups, and 15 bodyweight squats over a 20
minute time period, or a traditional resistance exercise (TRE) workout of bench
press, smith machine squat, incline DB press, 45° leg press, and lat pull downs (3-4
sets of 10 repetitions at 75% 1RM). Venous blood draws were performed prior to
(PRE) and immediately (PST), 15 min (15PST), and 30 min (30PST) post-exercise
to assess serum growth hormone (GH) and cortisol (CORT) responses. Heart rate
(HR) was also assessed at each time points. Subjects returned one week later
to complete the remaining protocol under previously standardized conditions.
Statistical analyses utilized a two-way ANOVA with repeated measures for heart
rate and serum hormone responses (p<0.05). RESULTS: A significant main effect
for time (p = 0.001) was observed for CORT with all time points significantly
elevated from PRE. A trend for significance (p = 0.060) was observed for a group
by time interaction suggesting that CORT responses were higher following TRE
vs. AMRAP. A significant main effect for time (p = 0.001) was observed for GH
with peak responses observed at PST with serum levels significantly decreasing
at 15PST and 30PST (PRE: 0.538 ± 0.82; PST: 25.35 ± 22.37; 15PST: 19.88 ± 19.09;
30PST: 14.12 ± 13.52 ng/mL); however, no significant group differences in GH were
observed between TRE vs. AMRAP. Additionally, a significant main effect for
time (p = 0.0001) was observed for HR with peak responses observed at PST
with HR significantly decreasing at 15PST and 30PST (PRE: 69 ± 10; PST: 125.9
± 17.2; 15PST: 99.6 ± 10.1; 30PST: 92.6 ± 11.4 bpm). No significant group by time
interactions (p = 0.221) were observed for HR. CONCLUSION: The key findings of
this study are that an AMRAP type of resistance exercise workout utilizing body
weight exercises can elicit a similar physiological response (GH, CORT, and HR) as
compared to a traditional bout of resistance exercise at 75% of 1RM. The AMRAP
protocol elicited the highest mean GH responses despite no significant differences
between groups. A trend for significance for CORT levels indicates that the TRE
elicited a slightly higher stress response. PRACTICAL APPLICATION: These
findings suggest that body weight resistance exercise can produce a sufficient
physiological stimulus in young resistance trained males when compared to a TRE. Despite these findings, there is limited evidence to support if this acute response
would translate into similar adaptations that are observed with traditional
resistance exercise. ACKNOWLEDGEMENTS: This study was funded by a Graduate
Faculty Research grant at the University of Mary Hardin-Baylor.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 16
AMBIENT AIR COOLING FOR EXTERNAL SOFT BODY ARMOR IN A HOT
ENVIRONMENT
G. A. Ryan1, R. L. Herron2, S. H. Bishop3, C. Katica2, B. Elbon4,
A. Bosak5, P. Bishop2
1
The University of Montana - Western, 2The University of Alabama,
3
Texas A&M University-Commerce, 4University of Alabama,
5
Armstrong Atlantic State University
Previously we have studied the impact of an ambient air induction system on heat
storage in concealed soft body armor (SBA) in a hot environment (wet bulb globe
temperature [WBGT] = 30 °C) over 60 min of exercise. The Level II SBA is also
regularly worn in a non-concealed manner outside the shirt by law enforcement
personnel. PURPOSE: The purpose of this study was to investigate the effects of
adding an ambient air induction system (~100 L/min) with 1.27 centimeter standoffs
to a Level II SBA, worn externally, on heat strain and perceived comfort compared
to an unmodified SBA worn externally. METHODS: Nine participants (27 ± 4 years)
completed two 60-min work bouts, consisting of cycles of 12-min walking (1.25 L
· min-1) and 3-min of arm curls (14.3 kg, 0.6 L · min-1) with a 5-min rest after every
other cycle in a counter-balanced manner with control and modified external
SBAs. Two-way repeated measures ANOVAs were used to assess the mean
differences for physiological measures (core temperature, heart rate, microclimate
[temperature and relative humidity]). Post hoc Bonferroni analysis and paired
samples t-tests (alpha = 0.01) were conducted on omnibus significant findings. Subjective measures (perceived exertion, thermal comfort) were analyzed using
Wilcoxon Signed Ranks Tests. RESULTS: No significant differences in rectal
temperature (p = 0.657), heart rate (p = 0.234), ratings of perceived exertion (p =
0.380), or thermal comfort (p = 0.107) were detected between the SBA trial and
the SBA modified with the ambient air system following the 60-min work bout. The microclimate under the modified SBA was significantly lower for the variable
back temperature at the 30-min (p = 0.002), 45-min (p ≤ 0.001), and 60-min (p
= 0.001) time points and back relative humidity at 15-min (p = 0.005), 30-min
(p = 0.009), 45-min (p = 0.010), and 60-min (p = 0.010) time points. Overall, a
reduction of 1.2 ± 0.2 °C in back temperature and 4.7 ± 1.2 %rH in back relative
humidity was noted between the control and modified SBA trials. No difference
was noted in microclimate in the front of the vest. CONCLUSIONS: While a small
change in back microclimate existed, this change was not associated with reduced
physiological (change in rectal temperature, or heart rate) or psychological
(ratings of perceived exertion, or thermal comfort) strain in individuals wearing a
modified non-concealed Level II SBA in a hot environment. Further improvements
to the ambient air system are needed to achieve reductions in physiological and
psychological strain. Additional research should be conducted to determine if
the shirt fabric (65/35 Cotton/polyester blend) impairs alleviation of heat strain
in individuals wearing external Level II SBA. PRACTICAL APPLICATIONS: The
data suggest that the introduction of ambient air was ineffective in improving
physiological or psychological parameters for individuals wearing an external
Level II SBA in a hot environment. However, these findings could be used to
suggest the need to change the fabric of both the SBA carrier and uniform worn
by law enforcement personnel to better alleviate heat strain associated with
wearing SBA in a hot environment.
Poster: 17
EFFECT OF TESTING INTENSITY LEVEL ON THE ACCURACY OF REPETITION
PREDICTION EQUATIONS TO ESTIMATE 1RM BEFORE AND AFTER TRAINING IN
COLLEGE WOMEN
J. L. Mayhew1, A. E. Smith-Ryan2, W. Kemmler3, D. Lauber3, A. Wassermann4
1
Truman State University, 2University of North Carolina Chapel Hill, 3University
of Erlangen, Erlangen, Germany, 4University of Bayreuth, Bayreuth, Germany
The applicability of a repetitions-to-fatigue (RTF) approach to predicting maximal
strength remains controversial. Previous prediction equations have shown varying
degrees of accuracy in estimating one-repetition maximum (1RM) strength levels
before and after training. While most evidence supports fewer RTF for accurate
prediction, women may be reluctant to use heavier loads to perform their RTF and
prefer using lower intensity loads. PURPOSE: To determine the effect of different
intensity levels of muscular endurance repetitions on the predictive accuracy of
equations to estimate 1RM before and after training in college women. METHODS:
163 college women (age = 18.9 ± 1.0 y, weight = 61.4 ± 10.9 kg) were assessed for
1RM free weight bench press and randomly assigned to one of 3 intensity testing
groups based on %1RM (Gr 1 = 60-69%, n = 53; Gr 2 = 70-79%, n = 47; Gr 3 = 8089%, n = 63). Repetitions-to-fatigue (RTF) were performed 2-3 days following 1RM
testing. Training was conducted 3X/wk for 12 wk, utilizing a linear periodization
model for all groups. Four prediction equations developed for women were
applied before and after training. RESULTS: There was no significant pre-training
difference in age, height, weight, or 1RM bench press among the intensity groups. 1RM improved significantly (p<0.05) by 22.8 ± 17.7% in the total sample following
training, with Gr 1 (16.9 ± 14.3%) increasing significantly less (p<0.01) than Gr 2
(24.9 ± 20.6%) and Gr 3 (26.2 ± 16.9%). Gr 1 (4.7 ± 6.9) significantly increased
(p<0.004) the number of RTF more than Gr 3 (1.0 ± 5.1) but not more than Gr
2 (2.6 ± 5.9); Gr 2 was not significantly different (p = 0.17) from Gr 3. Despite
these values, only 17 subjects decreased an intensity group and 5 increased an
intensity group. At pre-training, the Cummings and Finn equation significantly
overestimated (13.7 ± 4.7 kg) 1RM while the Reynolds et al. (0.06 ± 3.0), Mayhew et
al. (-0.5 ± 3.0 kg), and Tucker et al. (-0.5 ± 2.9 kg) equations were not significantly
different from actual 1RM. At post-training, the Cummings and Finn (17.7 ± 4.7 kg)
and Reynolds et al. (1.4 ± 4.3 kg) equations significantly overestimated 1RM while
the Mayhew et al. (0.4 ± 3.5 kg) and Tucker et al. (-0.6 ± 3.3 kg) equations were
not significantly different from actual 1RM. The Mayhew et al equation had the
largest number of subjects within ±10% of actual 1RM at both pre-training (65%)
and post-training (71%). The 95% limits of agreement (LOA) for this equation
were -5.4 to 5.6 kg. The best RTF range for prediction was 7-10RM at pre-training
and 3-6RM at post-training. CONCLUSION: A periodized resistance training
program emphasizing strength development can significantly increase upperbody strength in previously untrained young women. Improvements may be
similar for low-, medium-, and high-strength women. Certain repetition prediction
equations appear to accuracy for estimating 1RM bench press before and after
resistance training, with the optimal prediction in the 7-10RM range before training
and the 3-6RM after training. PRACTICAL APPLICATION: Periodized resistance
training programs are viable methods for enhancing upper-body strength in
young women. Repetitions can be used to predict 1RM and appear to be better
with some others. Repetitions in the 3-10RM range may be most suitable for
prediction accuracy.
Poster: 18
EFFECTS OF INTRA-SET REST INTERVALS ON MUSCLE ACTIVATION AND
POWER
S. A. McCleary1, J. M. Joy1, J. M. Oliver2, R. P. Lowery1, J. E. Dudeck1,
S. I. Weiner1, N. Carpenter1, E. Max1, D. Brockunier1, M. A. Naimo1, J. M. Wilson1
1
University of Tampa Human Performance Lab, 2Department of Kinesiology,
Texas Christian University, Fort Worth, TX
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Recent evidence has demonstrated hypertrophic training with intra-set rest
intervals results in the ability to produce greater power output and greater
strength gains following a 12 week periodized program. Further, no significant
differences were noted between lean mass gains when compared to traditional
hypertrophic training. However, the effect of intra-set rest intervals on power
output and the pattern of muscle activity over a single set are unknown.
Purpose: Therefore, the purpose of this investigation was to determine if intra-set
rest intervals produces greater power output and greater muscle activity during
the back squat exercise compared with traditional hypertrophic training over
repetitions in a single set. Methods: 10 trained males (21 ± 2 yrs, 183 ± 8 cm, 82.6
± 7.8 kg, 3 ± .5 yrs training) performed 1 set of 10 repetitions (TRD) and 2 sets of
5 repetitions with intra-set rest of 60 seconds (ISR) of the back squat with a load
corresponding to 75% 1RM in a randomized crossover design. Electromyography
(EMG) activity was measured during each repetition for the vastus lateralis (VL)
and biceps femoris (BF). Average power output was determined during each
repetition by linear position transducer. A 2 x 10 (INTERVENTION x REPETITION)
repeated measures ANOVA was used to determine differences in EMG activity and
average power output between interventions and over each repetition. Results: An effect of repetition in VL EMG activity approached significance (p=0.064)
with no significant difference observed between ISR and TRD (p>0.05). A
significant interaction was observed in BF EMG activity, in which post hoc analysis
revealed no significant differences. ISR produced significantly greater average
power output during latter repetitions (Repetition 6, 613±130W vs 541±117W; Rep
7, 602±141W vs 536±124W; Rep 8, 577±132W vs 514±86W; Rep 9, 551±125W vs
485±71W). Conclusions: ISR produces significantly greater power output during
latter repetitions in a single set of hypertrophic squat training. However, there
appears to be no significant difference in the muscle activity during the back
squat exercise. Practical Applications: The use of ISR in hypertrophic training is
evidenced by greater power output over a single set. Strength and conditioning
professionals should incorporate intra-set rest intervals during hypertrophic
phases of a training cycle, especially in programs designed for athletes involved
in power sports.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 19
THE PREVALENCE OF SEASONAL RESISTANCE TRAINING AMONG COMPETITIVE
MOUNTAIN BIKERS
S. M. Mitchell1, J. C. Higginbotham2, M. Richardson2, J. Wingo2, H. Gary2,
S. Usdan2, R. Henderson2
1
University of South Alabama, 2University of Alabama
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Mountain biking is characterized by intermittent bursts of power in an effort to
navigate off-road terrain. Mainstays in performance include peak power output
and power output at the lactate threshold up to the onset of blood lactate
accumulation. Resistance training (RT) has been shown to increase muscular
strength, and an increase in strength can increase power output by increasing
the velocity and force by which a muscle contracts. While studies have examined
the physiological parameters associated with successful riding, little is known
about how competitive mountain bikers train to increase performance. PURPOSE:
Therefore, the purpose of this study was to identify the prevalence of RT among
competitive mountain bikers in their effort to increase performance. METHODS:
Forty competitive mountain bikers (mean + SD, age 25.75 + 9.12 years) responded
to a nationwide online training survey. Participants for this study were recruited by
contacting groups whose members are competitive mountain bikers (i.e., NCAA
university teams, university sports club teams, sponsored teams, professional
teams). The survey assessed several types of training, including RT. Major
responses were examined to determine the reliability of the training survey.
Cronbach’s alpha value for reliability was 0.82. RESULTS: In-Season: Fifty-five
percent of respondents reported participating in RT during the in-season. Mean
number of workout sessions per week devoted to RT was 3.00(SD=1.19) days
per week. Median values of upper body and lower body training sessions were
2 and 3 sessions per week, respectively. Off-Season: Fifty-two and a half percent
of respondents reported participating in RT during the off-season. Mean number
of workout sessions per week devoted to RT was 2.76(SD=1.09) days per week.
Median values of upper body and lower body training sessions per week were
2.5 and 2.0 sessions, respectively. In-Season vs. Off-Season: Paired samples t-test
revealed no significant difference (t=0.82, df=15, p=0.42) in the number of workout
sessions per week between seasons. Wilcoxon signed rank analyses indicated no
significant difference in the number of upper (z=-1.40, p=0.16) and lower body (z=1.29, p=0.20) workout sessions between both seasons. Further analysis indicated
no significant difference in the percentages of riders participating in RT between
both seasons (z=0.09, p=0.46). CONCLUSION: Based on the study findings, RT
appears to be a popular modality of training to increase performance. In general, it
appears riders are adhering to the recommended frequency of workouts sessions
per week associated with increases in sport performance. Results from the
present study also suggest that riders incorporate upper and lower body training
sessions into their workout regimen. Overall, not only does the percentage of
participation in RT remain consistent throughout the year, results suggest there is
a certain amount of consistency among upper and lower body training between
both seasons. PRACTICAL APPLICATIONS: Technical terrain encountered during
an off-road competition incorporates variables of upper and lower body muscular
strength, endurance, and power. Resistance training has been shown to increase
these aforementioned variables. Coaches should consider implementing RT into
their athlete’s workout regimen. It is possible the riders who participate in RT may
have a competitive advantage over those who do not. Poster: 20
EFFECTS OF CITRULLINE MALATE ON REPEATED BOUTS OF LOWER-BODY
RESISTANCE EXERCISE
B. Wax1, K. Weldon1, A. N. Kavazis1, J. Sperlak1, B. Vickers1,
K. Gilliland1, M. Cook1
1
Subjects were randomly assigned to CM (8.0g) or placebo (PL) and performed five
sets of 60% of one-repetition maximum of leg press, hack squats, and leg extension
to failure. One week later, participants ingested the other supplement (CM or PL)
and repeated the identical protocol. Blood lactic acid was determined pre- and
immediately post-exercise. RESULTS: CM supplementation did not significantly
increase repetitions in the leg press (CM = 75.3 ± 23.7; PL = 72.0 ± 33.6, p > 0.05),
hack squat (CM = 38.0 ± 18.3; PL = 32.1 ± 12.8, p > 0.05), leg extensions (CM = 37.7
± 10.6; PL = 35.0 ± 12.9, p > 0.05), or total load volume (CM = 18822.4 ± 8277.0;
PL = 18171.4 ± 6724.6, p > 0.05). Blood lactate was significantly increased (p <
0.05) post-exercise compare to pre-exercise, but were not significantly different
between treatments (CM = 10.65 ± 1.41; PL = 10.74 ± 1.96, p > 0.05). CONCLUSION:
Collectively, these novel findings suggest that CM supplementation does not
increases muscular endurance during repeated bouts of lower-body resistance
exercise. PRACTICAL IMPLICATIONS: Our data suggest that acute CM ingestion
prior to lower-body exercise does not provide any ergogenic effect on resistance
performance, nor does it affect lactate production or clearance during anaerobic
exercise. These findings conflict with prior research, therefore further research is
warranted. Poster: 21
CARDIOVASCULAR AND METABOLIC DEMANDS OF THE TRX® METABOLIC
BLAST WORKOUT WITH SUSPENSION TRAINER®
R. Snarr1, E. Witte2, J. Verdy2, C. Jenkins2, M. Esco3
1
Auburn University Montgomery, 2Auburn University at Montgomery, 3Auburn
University Montgomery
*Award Eligible - Outstanding Master’s Student Poster Presentation
Recent trends in fitness have emphasized high-intensity resistance training
programs, functional programming, and stability training. The TRX® Metabolic
Blast workout was designed to incorporate these trends with the introduction of
a suspension device to a rapid, anaerobic workout program. However, there is
very little research about the demands these types of workouts place on the body. PURPOSE: The purpose of this investigation was to determine the cardiovascular
demands and metabolic cost of a high-intensity workout with a suspension device
in semi- to highly-trained individuals. METHODS: Twelve apparently healthy men
(n=9) and women (n=3), mean age = 24.93 ± 3.73, volunteered to participate in this
study. All participants performed the TRX® Metabolic Blast, a pre-programmed,
9.25 minute metabolic workout, consisting of nine exercises performed with a
suspension device, followed by a 1 minute cardio sprint on the treadmill. During
testing, subjects wore a portable metabolic analyzer (COSMED®K4b2) and a
Polar® heart rate monitor. The metabolic analyzer was used to determine volume
of oxygen consumed (VO2) and rate of caloric expenditure (kcals.min-1). RESULTS: The results demonstrated that the TRX® Metabolic Blast resulted in an average
heart rate of 152 ± 14.17 beats.min-1, or 85.20 ± 5.64% HRmax. Additionally, the
workout produced an average VO2 of 23.92 ± 3.14 ml.kg-1.min-1, which was 56.57
± 5.71% VO2max. Total caloric expenditure for the Metabolic Blast resulted in 95.57
± 18.42 kcals.min-1, or approximately 10.33 kcals.min-1. Overall, average MET
levels for the workout were equal to 6.83 ± 0.90. CONCLUSION: The results of
this investigation suggest that the TRX® Metabolic Blast could be classified as
“moderate intensity” exercise according to the established American College of
Sports Medicine guidelines. However, the workout elicited a high percentage of
HRmax, perhaps due to the anaerobic capacity needed to perform a high volume
of resistance training exercises. PRACTICAL APPLICATIONS: With the increasing
fitness trend favoring high-intensity interval training (HIIT) programs, the TRX®
Metabolic Blast generates a comparable caloric expenditure to traditional modes
of exercise (e.g., resistance training (8-10 kcals.min-1), running (12-22 kcals.min-1),
and cycling (10 - 15 kcals.min-1), etc.). However, with a moderate percentage of
VO2max elicited during the workout, cardiovascular adaptations may not be seen in
semi- to highly-trained individuals.
Mississippi State University
In the competitive arena of sports, athletes are continuously seeking training aids
and supplements that may provide them with the competitive edge. Recently, an
over-the-counter supplement named citrulline malate (CM) has shown promise
as a potential ergogenic aid during high-intensity bouts of resistance exercise.
PURPOSE: The aim of the study was to investigate the ergogenic properties of
CM during a lower-body resistance training protocol. Based on CM chemical
composition and prior study, we hypothesized that CM supplementation would
improve muscular endurance. METHODS: To test our hypotheses, twelve trained
males (age = 22.1 ± 1.4 yr, mass = 84.8 ± 10.9 kg, % body fat = 11.9 ± 4.3, height =
1.79 ± 0.10 m) participated in a randomized, counterbalanced, double blind study.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 22
EFFECT OF HIP INTERNAL ROTATION TRAINING ON RANGE OF MOTION AND
PERFORMANCE VARIABLES IN COLLEGIATE BASEBALL PITCHERS
B. Stover1, D. Szymanski1, T. Donahue1
1
Louisiana Tech University
*Award Eligible - Outstanding Master’s Student Poster Presentation
Hip range of motion (ROM) is very important to allow a pitcher to have proper
pitching mechanics. During the stride phase, the movement towards the target is
started by hip abduction of the dominant leg. As the pitcher continues down the
mound, the dominant hip internally rotates as the non-dominant hip externally
rotates. Previous research has shown that a limit in hip ROM may have a negative
effect in the ability to produce pitched ball velocity. PURPOSE: To evaluate the
effect of hip internal rotation training on hip ROM and related sport-specific
performance variables in baseball pitching. METHODS: Fourteen healthy NCAA
Division I collegiate baseball pitchers (age = 20.36 ± 1.50 yr) volunteered for
testing. All subjects signed an informed consent form according to the university’s
Institutional Review Board. A Baseline Absolute Axis 360° Digital Goniometer
(Fabrication Enterprises, Inc., White Plains, NY, USA) was used to measure passive
ROM for shoulder internal and external rotation at 90°, seated active hip internal
and external rotation, supine passive hip internal and external rotation, and hip
abduction and adduction. Deep squat was measured using a yard stick. A Biodex
(Biodex Medical Systems, Inc., Shirley, NY, USA) was used to measure internal and
external rotation at 90° of the throwing arm at 300°/sec. Flexibility was measured
using a sit-and-reach testing box. Sport-specific performance variables were stride
length and pitch velocity (PV). Stride length was measured with a measuring tape
from the front of the pitching rubber to the back of the pitcher’s lead heel after
each pitch. PV was measured using Stalker Pro radar gun (Applied Concepts, Inc.,
Plano, TX, USA). The velocity of 10 consecutive maximal effort fastballs with 20
seconds of rest between pitches was calculated to represent mean PV for each
subject. Participants were divided into 2 groups. Group 1 (n = 7) used the internal
hip rotation devices twice a day, 6 days a week for 7 weeks (84 total sessions). They
were instructed to stand on 2 hip rotation devices at 1 time. Then they initiated
movement by internally rotating 1 leg from the hip for 10 seconds, then the other
hip for 10 seconds while isometrically holding the other. They would do this twice
and then internally rotate both hips for 10 more seconds for a total of 30 seconds
for both hips. Group 2 (n = 7) served as a control and did not do any internal
rotation exercises. All other training during the off season was the same for both
groups. RESULTS: A two-way ANOVA with repeated measure showed that there
were significant differences (p < 0.05) within groups for shoulder internal and
external rotation, seated and supine internal and external hip rotation, and hip
abduction, but there were no significant differences observed between groups for
any variables. CONCLUSIONS: Improvements were seen in both groups in passive
and active ROM; however, there were no significant differences in any sportspecific performance variables. PRACTICAL APPLICATIONS: Using a hip internal
rotation device twice a day, 6 days per week for 7 weeks did not improve hip and
shoulder ROM or stride length any more than the control group after 7 weeks of
training for collegiate baseball pitchers. ACKNOWLEDGEMENTS: We would like to
thank CEU Now LLC for partially funding this study.
Poster: 23
THE INFLUENCE OF TRAINING STATUS ON THE RELATIONSHIP BETWEEN
MAXIMAL AND RAPID ISOMETRIC TORQUE VARIABLES
B. J. Thompson1, E. D. Ryan2, E. J. Sobolewski3, D. B. Smith4, K. Akehi4, E. C.
Conchola4, T. Buckminster5
1
Texas Tech University, 2University of North Carolina - Chapel Hill, 3The
University of North Carolina at Chapel Hill, 4Oklahoma State University,
5
Minor League Baseball
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Previous studies have examined the relationships between maximal and rapid
isometric force/torque variables and have reported that different physiological
parameters may be associated with the early and later portions of the force
or torque-time curve. However, we are aware of no previous studies that
have examined these relationships when comparing trained athletes and
healthy recreationally active college-aged controls. PURPOSE: To examine the
relationships between maximal and early and late rapid isometric torque variables
in elite Division I collegiate football players and recreationally active collegeaged controls. METHODS: Thirty-one NCAA Division I collegiate football players
(mean±SD: age=20.6±1.5 years; stature=183.4±8.6 cm; mass=106.7±22.0 kg) and
twenty-six college-aged male controls (age=24.9±3.0 years; stature=178.3±7.0;
mass 85.4±11.3 kg) performed two leg extension isometric maximal voluntary
contractions (MVCs) on a calibrated isokinetic dynamometer. Participants were
instructed to push “as hard and fast as possible” for 3-4 s. Peak torque (PT) was
determined from the highest 500ms epoch along the entire torque-time curve
and rate of torque development (RTD) was calculated as the linear slope (Nm·s1) at the epoch intervals of 0-30, 0-50 and 100-200ms from the onset of torque
production (7.5 Nm above baseline). The PT (Nm·kg-1) and RTD (Nm·s-1·kg-1)
variables were normalized to body mass prior to all statistical analyses. Pearson
product-moment correlation coefficients (r) and coefficients of determination (r2)
were used to evaluate the relationships among these variables. RESULTS: The
Pearson correlations and coefficients of determination are presented in the table.
All RTD variables were significantly correlated to PT for both the athletes (P <
0.001) and controls (P < 0.001 – 0.003). CONCLUSIONS: The present findings
revealed that RTD at both the early (30 and 50ms) and late (100-200ms) torquetime epochs were correlated to PT in both the athletes and the controls. Similar
to previous studies in non-athletes, voluntary RTD becomes more dependent on
maximal strength at later onsets of contraction (0-30 vs. 100-200ms). However,
PT accounted for a similar percentage of the variance (55 – 64%) in both early
and late RTD variables among athletes, suggesting that early RTD variables are
more dependent upon maximal strength following chronic resistance training.
PRACTICAL APPLICATIONS: Since many sporting events and functional
performances include activities such as running, accelerating, and cutting which
require short foot strike contact times (<100ms), examining the relationship
between rapid contractile variables and maximal strength may help practitioners
and coaches determine optimal training programs to improve these important
neuromuscular characteristics. Poster: 24
RELATIONSHIP BETWEEN THE ANTHROPOMETRIC ESTIMATION OF
UNILATERAL THIGH MUSCLE CROSS-SECTIONAL AREA AND PEAK ECCENTRIC
SQUAT FORCE
J. Travis1, M. S. Stock1, M. Luera1
1
Texas Tech University
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
The results from many previous studies indicate that the force a muscle can produce
is related to its cross-sectional area (CSA) rather than its volume. However, the
majority of these investigations have measured force during single-joint isometric
or concentric muscle actions. PURPOSE: The purpose of this study was to use linear
regression analyses to determine the relationship between the anthropometric
estimation of right thigh muscle CSA and peak eccentric squat force using a novel
multiple-joint strength assessment. METHODS: Nineteen resistance-trained men
(mean ± SD age = 22 ± 2 years) participated in this investigation. The subjects were
engaged in a lower-body strength training program that involved back squats
and/or deadlifts. Forty-eight hours following a thorough familiarization session,
the subjects visited the laboratory for data collection. Upon arrival, a technique
for estimating muscle CSA from anthropometric measurements for the thigh was
performed. The measurements included femur length, thigh circumference, and
four skinfolds (anterior, posterior, lateral, medial). The subjects then performed
three consecutive repetitions of maximal eccentric isovelocity squats. The duration
was set to four seconds for each attempt, and an electrogoniometer placed over
the right knee joint ensured that each repetition was performed through an 80°
range of motion (in accordance with the manufacturer’s guidelines for eccentric
strength testing [20°/second]). The repetition with the greatest force values
was selected, and the highest peak in the force curve was used for data analysis.
Linear regression analyses were used to determine the relationship between the
anthropometric estimation of thigh muscle CSA and peak eccentric squat force.
RESULTS: The correlation (Pearson r) between these variables was r = 0.01. The
regression equation was y = 0.0005 (cm2/N)x + 222.9 cm2. Both negative and
positive values were included in the 90, 95, and 99% confidence intervals (CIs).
The estimation of unilateral thigh muscle CSA from anthropometric measurements
explained none of the variance in peak eccentric squat force. We speculate that
these results could be related to the different types of training programs used by
the subjects (e.g., training primarily for strength and power versus hypertrophy)
or the force contributions of the musculature involved in the squat that were not
estimated with our anthropometric measurements (e.g., gluteus maximus, erector
spinae, gastrocnemius, etc.). PRACTICAL APPLICATIONS: Although previous
authors have shown a linear relationship between muscle CSA versus isometric
and concentric force, no such association exists for maximal eccentric squats.
Our findings are specific to men with previous strength training experience and
eccentric strength testing conditions involving a standardized movement pattern
and range of motion.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 25
REST INTERVAL LENGTH IN BETWEEN SETS INFLUENCES ACUTE ANABOLIC
HORMONAL RESPONSES AND PERFORMANCE DURING 8 WEEKS OF
PERIODIZED RESISTANCE TRAINING IN OLDER MEN
M. G. Villanueva1, C. J. Lane1, E. Schroeder1
1
University of Southern California
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Purpose: To determine: i) if strength resistance exercise protocols (SRE) with
60-second rest interval lengths (RI) between sets (SS) will elicit significantly
greater acute increases in total testosterone (TT) and growth hormone (GH),
compared to SRE prescribed with 4-minute RI between sets (SL); and ii) if 8
weeks of periodized strength resistance training (RT) incorporating 60-second
RI in between sets (SSRT) will induce greater improvements in body composition
and muscular performance, compared to the same RT program incorporating
4-minute RI (SLRT). Methods: 22 men (SSRT: n=11, 65.6±3.4 years; SLRT: n=11,
70.3±4.9 years) were assigned to one of two groups, following 4 weeks of
periodized hypertrophic RT (PHRT). From Week 4 to Week 12, SSRT and SLRT
followed the same periodized strength RT program, with RI the only difference
in RT prescription. 18 of the 22 participants completed 1 acute hypertrophic RE
protocol (HRE), prior to the 12-week periodized RT program, and 2 SRE; SRE 1 was
completed at Week 4 and SRE 2 upon completion of the RT program (Week 12). Blood was drawn pre- (PRE), immediately post- (POST), 15 minutes post- (15 MIN),
and 30 minutes post-exercise (30 MIN), to determine blood concentrations of TT
and GH. Results: Following PHRT, all study participants experienced increases in
lean body mass (LBM), maximal upper and lower body strength, stairclimbing
power, and dynamic balance (p<0.05). All study subjects experienced significant
decreases in percentage body fat, stairclimbing time, and 400-meter walking
time (p<0.05). Across the 8-week strength RT phase, compared to SLRT, SSRT
experienced significantly greater increases in LBM (p=0.001), upper and lower
body maximal strength (p<0.01), and stairclimbing power (p<0.001). HRE (n=18)
increased TT, from PRE to POST, 15 MIN, and 30 MIN (p≤0.05); for GH, elevations
above PRE were also significant at POST, 15 MIN, and 30 MIN (p<0.01). In response
to SRE 1 and SRE 2, there was a significant effect for protocol on TT acute change
([POST] – [PRE]) (p<0.001) and percent change ([POST – PRE]/[PRE]) (p=0.001;
See Figure); the acute elevations in TT in response to SS were significantly greater,
compared to SL. There was also a significant effect for protocol on GH percent
change (p=0.003); the acute elevations in GH in response to SS were significantly
greater, compared to SL. Conclusions: Strength resistance exercise with short rest
interval lengths in between sets increases acute TT and GH responses in older
men, while long rest interval lengths in between sets blunt the acute TT and GH
response to strength resistance exercise. Further, 8 weeks of periodized highintensity strength RT with short rest interval lengths in between sets induces
significantly greater enhancements in body composition, muscular performance,
and functional performance, compared to the same RT prescription with long rest
interval lengths in between sets. Practical Applications: This study gives insight
into a new approach to prescribing strength resistance exercise and periodized
strength resistance training for older men, in order to optimize hypertrophic
and performance adaptations to short-term strength resistance training and
maximally offset the age-related declines in lean body mass, strength, and power.
Acknowledgements: This study received funding through the National Strength
and Conditioning Association Foundation (NSCAF).
Poster: 27
THE ACCURACY OF BIOELECTRICAL IMPEDANCE FOR MEASURING BODY FAT
PERCENTAGE IN INDIVIDUALS WITH DOWN SYNDROME
B. Nickerson1, A. R. Russell1, S. Bicard1, A. Mahurin2, M. Esco1
1
Auburn University Montgomery, 2Baptist Family Residency Program
*Award Eligible - Outstanding Master’s Student Poster Presentation
Individuals with Down syndrome (DS) have been shown to have a higher prevalence
of obesity and a different pattern of body fat distribution compared to individuals
without DS. Predicting body fat percentage (BF%) in this special population is
important when establishing life style interventions designed to promote healthy
body weight. Foot-to-foot bioelectrical impedance analysis (FF-BIA) is a simple
and inexpensive method for predicting BF% in field and clinical settings. Various
studies have measured the accuracy of FF-BIA in the general population. However,
there is very little research to date cross-validating FF-BIA in individuals with DS.
Therefore, the accuracy of inexpensive and non-invasive field techniques such as
FF-BIA needs to be determined. PURPOSE: The purpose of this investigation was
to cross-validate FF-BIA for measuring BF% in individuals with DS. METHODS:
Twelve adults and five adolescents with DS (n=17) participated in the study. BF%
was measured with FF-BIA. Criterion BF% was determined via dual-energy
x-ray absorptiometry (DXA). RESULTS: Mean BF% was 35.68 ± 13.35 for DXA
and 32.35 ± 11.83 for FF-BIA (p<0.05). The FF-BIA significantly correlated with
the DXA (r=0.88, p<0.05) and had a standard error of estimate (SEE) of 6.40%.
CONCLUSIONS: The findings suggest that on average the FF-BIA underestimated
BF% by 3.33%. FF-BIA is highly correlated with the DXA, but has a high SEE. More
research with a larger sample size is warranted. PRACTICAL APPLICATIONS:
FF-BIA is a method of measuring body fat that could become widely used to
predict BF% in individuals with DS in clinical and fitness settings due to its quick
administration and non-invasive nature. However, practitioners should consider
the results of this investigation before using the FF-BIA for measuring BF% in
this special population. It appears to underestimate BF% values and has a large
range of standard error. Therefore, caution should be taken when using FF-BIA to
predict BF% in individuals with DS.
Poster: 28
Poster: 26
AN ELECTROMYOGRAPHIC COMPARISON OF A MODIFIED PULL-UP WITH AND
WITHOUT A SUSPENSION DEVICE
E. Witte1, R. Snarr2, C. Jenkins1, R. Brannan1, M. Esco3
1
(PU) versus a modified suspension pull-up (SPU). Methods: Fifteen healthy men
(n = 11, ages 26.82 ± 4.02 years) and women (n = 4, ages 22.25 ± 0.96 years)
participated in the study. All participants completed 4 repetitions of the PU and
SPU. Mean peak EMG values were recorded and used for data analysis for each
muscle group. Results: The PU demonstrated values of: MT = 2.53 ± 1.33, PD =
2.67 ± 1.24, LD = 3.49 ± 2.07, BB = 4.69 ± 1.76. The SPU elicited values of: MT =
2.35 ± 1.34, PD = 2.72 ± 1.12, LD = 3.44 ± 1.92, BB = 4.48 ± 1.71. The results indicated
that there were no significant differences between PU and SPU (p > 0.05) in EMG
activity of each tested muscle. Conclusions: This study showed no significant
difference in muscle activity for the measured muscle groups (MT, PD, LD, and BB)
when performing a modified pull-up with and without a suspension device. Further
study is warranted to determine muscle activation values in smaller stabilizing
muscles while performing the PU and SPU. Practical Applications: Practitioners
should note that there are no measurable differences in muscle activation when
performing a PU compared to a SPU. Therefore, a suspension device may be used
in place of traditional stable equipment to elicit similar muscular activation levels
in the MT, PD, LD, and BB while performing a modified pull-up.
Auburn University at Montgomery, 2Auburn University Montgomery,
3
Auburn University Montgomery
*Award Eligible - Outstanding Master’s Student Poster Presentation
The use of suspension devices for performing traditional exercises is a relatively
new method of training that utilizes novel equipment designed to challenge
stability. There is very limited research available to determine if such training
influences muscular activation patterns compared to traditional exercise. The
standard pull-up is an exercise that targets a large portion of the upper body, but
is challenging for some individuals. This movement can be modified by placing the
lower limbs on a stable, supportive surface underneath the body while performing
the pulling movement. Purpose: The purpose of this study was to compare the
electromyographic (EMG) activity of the middle trapezius (MT), latissimus dorsi
(LD), posterior deltoid (PD), and biceps brachii (BB) during a modified pull-up
SPRINT MOMENTUM BUT NOT SPRINTING SPEED DIFFERENTIATE
SENIOR INTERNATIONAL RUGBY PLAYERS FROM
JUNIOR INTERNATIONAL RUGBY PLAYERS
M. Barr1, J. M. Sheppard2
1
Rugby Canada, 2Edith Cowan University
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: Speed is considered to be a highly valuable ability in rugby union and
a key component of a team’s success. Sprint momentum, the combination of
sprinting velocity and body mass, is also likely important given the large number
of collisions that take place in rugby games. There is little research, however,
investigating the importance of sprint momentum in elite rugby union players. The aim of the current study was to examine the importance of sprint momentum
in differentiating playing level of elite rugby players. METHODS: Participants in
this study included 38 senior national team players (21 forwards, 17 backs) and 31
junior (under-20) team players from the same country’s national team (typically
11th-14th place in the International Rugby Board world rankings). In order to
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
assess sprinting speed and sprint momentum, each participant performed four 40
m sprints on artificial turf. Timing gates (Brower, Utah) were set on 1m tripods at
the 0m, 10m, 30m and 40m marks. Participants began their sprint with their front
foot beside a cone 0.75m behind the first gate. The fastest 0-10m and 30-40m
sections from the sprints were kept for analysis in order to characterize different
sprint qualities. The 0-10m split was used to analyze acceleration ability and
the 30-40m section was used to analyze maximal velocity. The times from each
section were converted into a velocity by dividing the 10m section by the time
taken to complete it. The 0-10m section was considered Initial Sprint Velocity
(ISV) and the 30-40m section was considered Maximal Sprint Velocity (MSV). In
order to calculate momentum, the velocity scores were multiplied by the body
mass of each athlete to calculate Initial Sprint Momentum (ISM) and Maximal
Sprint Momentum (MSM). A 2x2 ANOVA (senior-junior x forward-back) was used
to compare body mass, sprinting velocities and sprint momentum scores. If a
significant F value was found, post hoc tests (Tukey’s) were conducted to obtain
between-group differences. RESULTS: The results indicate significant differences
between senior and junior players for ISM and MSM but not for ISV and MSV. Significant differences were also found between senior and junior players for
body mass. CONCLUSION: The results seem to indicate that body mass and
sprint momentum but not sprinting velocity differentiate between the senior
and junior players. Findings from the study suggest that sprint momentum and
body mass are key physical qualities to develop in young players transitioning
into senior international rugby. Longitudinal studies, however, will be needed
to confirm these findings. PRACTICAL APPLICATIONS: When testing sprinting
speed in rugby players, strength and conditioning coaches should use 10m splits
in order to calculate sprint momentum. In addition to developing sprinting speed,
strength and condition coaches working with elite rugby players should focus on
developing sprint momentum as it is a key physical quality. Poster: 29
EFFECTS OF ASSISTED JUMP TRAINING ON VERTICAL JUMP PERFORMANCE IN
NCAA DI WOMEN VOLLEYBALL PLAYERS
T. L. Beaudette1, A. M. DuBois1, L. E. Brown2
1
California State University, Fullerton, 2Center for Sport Performance,
California State University, Fullerton, CA
*Award Eligible - Outstanding Master’s Student Poster Presentation
INTRODUCTION: Vertical jump performance plays an important role in the
performance of volleyball players. Assisted jumping research has been shown to
acutely increase peak vertical jump, but the adaptations resulting from chronic
assisted jump training are currently unknown. PURPOSE: To investigate the effects
of assisted plyometric jump training on peak jump height and net relative impulse
during bodyweight vertical jumps. METHODS: Eight NCAA Division I women’s
volleyball players (19.25 ± 0.89 yrs.; 182.84 ± 3.72 cm; 72.2 ± 9.28 kg) performed
three maximal baseline countermovement vertical jumps with arm swing followed
by four weeks of assisted plyometric jump training. During the first two weeks,
subjects performed 2 sets (week 1) and 3 sets (week 2) of 10 jumps at 30%
bodyweight reduction (BWR). During the last two weeks, subjects performed 2
sets (week 3) or 3 sets (week 4) of 10 jumps at 40% BWR. Subjects wore a full
body harness attached to elastic cords that were stretched from the ceiling by
a rope. Using a pulley system, the cords were pulled by the rope adjusting the
specified BWR for each trial. After four weeks of training, subjects performed three
maximal post vertical jumps with arm swing. All vertical jumps were performed
on an AMTI force plate sampling at 1000 Hz. Peak jump height and net relative
impulse were calculated during each maximal vertical jump via custom LabVIEW
software. RESULTS: Peak jump height significantly (p < 0.05) increased (pre =
33.5286 ± 5.34 cm; post = 35.3541 ±6.42 cm). However, there was no significant
(p > 0.278) change in net relative impulse (pre = 2.64 ± .17 N·s-1·kg-1; post = 2.67 ±
0.21 N·s-1·kg-1). CONCLUSIONS: Given the increase in peak vertical jump, assisted
jump training could be an effective training technique for improving performance
in jumping athletes. The increase in peak jump height might be attributed to
variables other than net relative impulse, which merits further research of assisted
jump training. For future research it might be beneficial to extend the length of the
assisted training program beyond 4 weeks and evaluate other variables that might
be contributing to increases in vertical jump, such as force, velocity, and power. PRACTICAL APPLICATIONS: Since assisted jump training can be performed with
minimal fatigue, implementing assisted training into an ongoing training program
might increase an athlete’s vertical jump height without effects of overtraining. Poster: 30
THE EFFECTS OF WHOLE-BODY VIBRATION ON GROUND REACTION FORCES
AND RATE OF FORCE DEVELOPMENT IN COLLEGE AGED FEMALES
N. C. Dabbs1, H. Chander2, C. Allen1, J. Lundahl1, V. L. Cazas2,
M. Hilton1, M. Italia1, J. C. Garner2
1
The University of Mississippi, 2University of Mississippi
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Varsity and recreationally trained individuals have previously shown to potenitate
vertical jumping performance following exposure to whole-body vibration (WBV).
However, determining the optimal rest intervals is still unclear. Purpose: The
purpose of this study was to evaluate the influence of different rest intervals
following WBV on rate of force development (RFD) and relative ground
reaction forces (rGRF) in varsity and recreationally trained females. Methods:
Eight varsity (age 20.75 ± 1.16yr, mass 61.35 ±9.68kg, height 168.19 ±7.73cm)
and eight recreationally (age 22.25 ±1.83yr, mass 64.35 ±4.64kg, height 162.53
± 2.6cm) trained females completed the study using four visits. Visit one acted
as a familiarization visit and visits 2-4 involved two randomized conditions, each
with a 10min washout period between conditions. WBV was administered on a
Power plate tri-axial platform with a frequency of 30Hz, an amplitude of 2-4mm
while performing four bouts of 30s of quarter squats. WBV was followed by 3
countermovement vertical jump (CMVJ) with one of five different rest intervals;
0s, 30s, 1min, 2min, 4min. A non-vibration control and collapsed maximum
condition were also incorporated. Dependent variables of interest are rate of force
development (RFD) and relative ground reaction force (rGRF). Results: Difference
in RFD and rGRF were analyzed with a 2x7 (training status by condition) mixed
factor ANOVA.There were no significant (>0.05) group differences, therefore
groups were collapsed.No significant (>0.05) interaction of training status by
condition was found for RFD or rGRF. There was a significant (<0.05) main effect for
both RFD and rGRF. This was followed up with a least significant difference (LSD)
pairwise comparison demonstrating that collapsed maximum values, regardless
of rest interval, were significantly (<0.05) greater than the control condition in
both RFD and rGRF. Conclusion: This indicates that both varsity and recreationally
trained individuals are positively influenced by whole-body vibration exposure.
However, improvements are seen following different rest intervals suggesting
strong individual differences in optimal rest times. Practical Application: Coaches
and practitioners should test individuals optimal rest time for optimal performance
measures to ensure full jumping performance capabilities.
Poster: 31
EFFECT OF STATIC VS. DYNAMIC WARM-UP ON BAT VELOCITY
B. Marquez1, L. E. Brown2, J. W. Coburn2, G. J. Noffal2, L. Truong2
2
1
Center for Sport Performance/California State University, Fullerton,
Center for Sport Performance, California State University, Fullerton, CA
*Award Eligible - Outstanding Master’s Student Poster Presentation
PURPOSE: It is imperative that athletes properly prepare their muscles by using
effective pre-exercise warm-up routines prior to their sporting event in order
to maximize performance. Therefore, most athletes and coaches try to select
and perform the most desirable warm-up routines. In baseball, there are many
skills involved in being a successful hitter with bat velocity being a major factor.
The purpose of this study was to examine the effect of static stretching (S) vs.
dynamic (D) warm-up on bat velocity. METHODS: Ten male (age 24.0 ± 2.41 years,
height 180.41 ± 7.50 cm, and mass 87.05 ± 11.25 kg) and 10 female (age 23.6 ± 1.69
years, height 165.16 ± 6.89 cm, and mass 61.78 ± 8.70 kg) recreational baseball
and softball players gave IRB approved informed consent and participated in
this study. They completed three testing sessions, on consecutive days using 3
different randomized 90s warm-ups (D was 3 repetitions of forward lunges with
rotation, standing rotations and lateral lunges; S was the same 3 exercises as D
but stationary; control (C) rested). These were then analyzed for their effect on
max bat velocity. After each condition, subjects performed 3 sub-maximal swings
followed by 30s rest then 5 maximal swings. To measure bat speed, subjects stood
on a batter’s box grid and had their rear heel position recorded to ensure body
position replication on subsequent visits. The batter’s box grid was a 3 X 5 foot
rectangle comprised of 2 inch squares, which ensured subjects were in the same
starting position for every swing. The grid was situated in front of a custom bat
velocity measurement device, which consisted of 2 vertical photoelectric sensors
separated by 45 cm (the depth of home plate). The sensors were situated so
they matched with the front and rear of a simulated home plate. Each subject
positioned themselves at the plate in the same manner as they would in a real
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
hitting scenario. They then swung the bat through the device activating the 2
sensor lights in succession, which sent signals to a data acquisition computer
sampling at 10,000 Hz (due to a high bat velocity over a short distance between
sensors) running custom software. All subjects used the same bat for all swings.
The distance was then divided by time, resulting in average bat velocity. RESULTS:
ANOVA revealed no interactions or main effects for condition (males D-56.04 ±
9.49, S-56.98 ± 9.98, C-58.61 ± 7.14 mph; females D-43.19 ± 6.97, S-43.08 ± 6.48,
C-42.02 ± 8.56 mph). There was a main effect for sex with males demonstrating
greater bat speed than females. CONCLUSIONS: Our results indicate that
performing a 90s warm-up consisting of static stretching, dynamic movements,
or control demonstrates no difference in subsequent max bat speed. PRACTICAL
APPLICATIONS: Therefore, players should choose the warm-up of their preference.
Future research should examine different durations, rest times and movements, in
order to determine an optimal warm-up for a player in the batter’s box prior to
swinging a bat with maximum speed.
Poster: 32
EFFECT OF CLUSTER SETS ON PLYOMETRIC JUMP PERFORMANCE
S. Moreno1, L. E. Brown1, J. W. Coburn1, D. A. Judelson1
1
Center for Sport Performance, California State University, Fullerton, CA
*Award Eligible - Outstanding Master’s Student Poster Presentation
PURPOSE: Many sport coaches utilize plyometric training to develop the
efficiency of an athlete’s stretch-shortening cycle. Knowing the importance of
this mechanism, it is imperative that an optimal plyometric program design is
administered by coaches. Cluster sets may allow for enhanced power production
due to recovery of energy substrates. Therefore, the purpose of this study was
to determine the effect of cluster sets vs. traditional sets on plyometric jump
power (PW), ground reaction force (GRF), take-off velocity (TOV), and jump
height (JH). METHODS: Twenty-six recreationally trained men gave University
approved informed consent then completed three testing sessions (7 days apart),
involving repeated body-weight plyometric jumps with hands on hips for three
different plyometric set configurations: traditional (2 sets of 10 with 90 seconds
rest), Cluster 1 (4 sets of 5 with 30 seconds rest), and Cluster 2 (10 sets of 2 with
10 seconds rest). All jumps were performed on a force plate sampling at 1000
Hz and analyzed with custom software. RESULTS: GRF results demonstrated no
interaction or main effect for condition, but there was a significant (p < .05) main
effect for repetition, where repetition 1 was significantly less than repetitions 3-5,
7-10, 12-15, and 17-20. For TOV, PW, and JH, there were significant interactions. TOV resulted in the following: Traditional, repetition 1 was significantly greater
than repetitions 7-10 and 17-20, but was significantly less than repetition 13; Cluster
1, repetition 1 was significantly less than repetitions 2-5; Cluster 2, there were no
significant differences. PW resulted in the following: Traditional, repetition 1 was
significantly greater than repetitions 4-10 and 14-20; Cluster 1, repetition 1 was
significantly greater than repetitions 7-10 and 12-20; Cluster 2, repetition 1 was
significantly greater than repetitions 3, 6-18 and 20. JH resulted in the following:
Traditional, repetition 1 was significantly greater than repetitions 18- 20, but was
significantly less than repetitions 3 and 13. For Cluster 1 and Cluster 2, there
were no significant differences. CONCLUSIONS: These results demonstrate that
cluster sets allow for a greater maintenance of PW, TOV, and JH when performing
repeated plyometric jumps. The 2x10 condition used a work to rest ratio of 1:9,
which allowed for near-complete recovery, unlike the 4x5 and 10x2 conditions. Also, there were substantial decreases in power after the third and fifth repetitions
of the 2x10 and 4x5 conditions, respectively. However, the traditional set was
the only configuration that showed significantly greater jump heights across
repetitions. PRACTICAL APPLICATIONS: Therefore, one should execute no more
than 5 repetitions to avoid fatigue, but greater than 2 repetitions to elicit the large
eccentric loads derived from repetitive jumps. Overall, coaches should have their
athletes perform 3-5 jumps with 27 and 45 seconds rest, respectively.
Poster: 33
HIGH INTENSITY INTERVAL TRAINING HAS POSITIVE EFFECTS ON SKELETAL
MUSCLE HYPERTROPHY, POWER, AND ON-ICE PERFORMANCE
M. A. Naimo1, J. M. Wilson1, A. L. Carpenter1, P. Gilchrist1, B. Averbuch1,
R. P. Lowery1, E. Oliveira de Souza2, J. M. Joy1, T. M. White1, M. Welton1
1
University of Tampa Human Performance Lab, 2Laboratory of Neuromuscular
Adaptations to Strength Training, School of Physical Education and Sport,
University of São Paulo
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Introduction and Objective: Research has shown that high intensity interval
training (HIIT) produces greater improvements in anaerobic power, larger
increases in aerobic capacity, and higher reductions in body fat despite significant
reductions in training volume compared to moderate intensity, continuous
endurance exercise (traditional). In spite of the well-known benefits that have
been demonstrated through research on HIIT, very few studies have looked at the
practical applications of interval training on performance in sport. Specifically, no
study has ever sought to investigate the effects of HIIT on measures of skeletal
muscle hypertrophy, body composition, power, and on-ice performance in
hockey players. Therefore, our purpose was to investigate the effects of a 4-week
periodized HIIT training program using the Wingate Anaerobic Test (WanT) on
measures of skeletal muscle hypertrophy, body composition, power, and onice performance in collegiate hockey players. Methods: Twenty-four hockey
players from The University of Tampa men’s club hockey team aged 19.6 ± 1.3
years, 180.0 ± 7.0 cm, 79.9 ± 8.3 kg, and a BMI of 24.7 ± 2.5 with at least three
continuous years of hockey experience participated in the study. The participants
were randomly assigned to either a traditional or interval group during a four
week training program in which they trained twice per week. The traditional
group performed continuous moderate intensity cycling for 45-60 minutes per
session at an intensity that was 65% of their heart rate reserve. The interval group
was involved in a periodized HIIT program in which participants performed 4-10
sets of WanT at an intensity of 7.5-10% of body weight with 2-4 minutes rest in
between sets. Participants performed three on-ice measures, which included 6 x 9
m stops, a 33 m sprint test, and a 127 m endurance test. In addition, participants’
quadriceps muscle thickness, lean body mass (LBM), WanT peak power, and WanT
average power were all assessed pre- and post-training. A repeated measures
ANOVA was used to determine differences between groups, and a tukey post-hoc
analysis was used to locate differences. Results: Groups differed largely in terms
of average training volume per week (27.3 min●week-1 vs. 105 min●week-1). There
were no significant training effects on LBM and body fat percentage. However,
∆ quadriceps muscle thickness significantly increased in the interval group
compared to the traditional group (2.1±1.4% vs. -1.9±1.2%, p=0.01). In addition,
there were significant group x time effects for both ∆ peak power (p < 0.003)
and ∆ average power (p < 0.02) in which the interval group had greater values
compared to traditional. While there were no training effects for the ∆ 6 x 9 m
stops (p > 0.13), there was a trend for faster ∆ endurance test time to completion
(p=0.08) and a significantly faster sprint (p<0.02) time to completion for the
interval group. Conclusion: These results indicate that HIIT may be utilized by
athletes in order to elicit improvements in skeletal muscle hypertrophy and power.
Moreover, these changes in skeletal muscle mass and power can be used in order
to improve performance in a sport-specific setting. Therefore, a periodized, HIIT
program is a time efficient strategy that can be utilized by coaches and strength
and conditioning practitioners in order to improve markers of skeletal muscle
hypertrophy, power, and on-ice performance in hockey players.
Poster: 34
POSITIONAL COMPARISON OF REACTIVE STRENGTH INDEX IN
HIGH SCHOOL BASEBALL PLAYERS
K. Srinivasan1, R. Ferrell1, P. Damrath1, C. Minor1, D. Meyers1, S. Hussein1,
A. Coleman1, T. Dupler1, W. E. Amonette1
1
University of Houston, Clear Lake, Department of Clinical, Health and Applied
Sciences, Human Performance Laboratory
*Award Eligible - Outstanding Master’s Student Poster Presentation
The ability to generate maximum force in minimal time is a requisite in most
sports. Reactive strength index (RSI) is a measure of explosive strength and is
computed as the ratio of ground contact time (GCT) and vertical jump height
(VJHT). Previous research indicates that it may be a predictor of peak force and
power capabilities. It may be an efficient method to determine general athletic
ability, especially when time and equipment are constrained. PURPOSE: To
quantify vertical jump (VJ) kinetics and RSI from depth box jumps in high school
baseball players and determine differences between playing positions. METHODS: NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Data were collected on 33 male high school baseball players between the ages
of 16-18y. The sample included 11 pitchers (PIT; 16.4 ± 0.7 y; 184.3 ± 5.0 cm; 78.6
± 26.1 kg; 19.2 ± 12.7 %Fat), 5 catchers (CAT; 16.2 ± 0.5 y; 175.3 ± 4.6 cm; 75.7 ±
12.5 kg; 20.9 ± 14.1 %Fat), 10 infielders (IF; 16.8 ± 7.1 y; 175.0 ± 8.1 cm; 68.9 ± 14.2
kg; 18.7 ± 7.3 %Fat), and 7 outfielders (OF; 16.9 ± 0.7y; 174.5 ± 7.7; 71.3 ± 6.3kg;
12.4 ± 3.5 %Fat). Athletes completed tests in the order of height (HT; cm), body
mass (BM; kg), body composition (%Fat), a standardized warm up session, vertical
jump (VJ), and depth box jumps from 15, 30 and 46 cm. HT was determined using
stadiometer and BM using an electronic scale. Percent fat was determined using a
3-site skinfold assessment performed by a single investigator. VJ was tested using
a countermovement jump on a force platform. For depth jumps, participants
stood on a 15, 30, and 46 cm box, stepped off the box, landed on the force
platform, and quickly jumped as high as possible. VJ and depth jump kinetic and
kinematic data were collected at 400 Hz. Peak power (VJPP) was determined from
VJ using the computed velocity of the center of mass times the vertical ground
reaction force. RSI for the 15 (RSI15), 30 (RSI30), and 46 (RSI46) cm boxes were
computed from the depth jump data as the VJHT (cm) divided by GCT (msec). A
one-way ANOVA was used to determine differences between playing positions in
VJPP, RSI15, RSI30, and RSI46. RESULTS: There were no significant differences
(p=0.53) in VJPP between PIT (66.17 ± 41.4 W), CAT (52.5 ± 7.3 W), IF (55.89 ± 7.3
W), and OF (57.99 ± 4.5 W). Likewise, RSI15 (p=0.47) values between PIT (0.71 ±
0.22 cm.msec-1), CAT (0.69 ± 0.17 cm.msec-1), OF (0.89 ± 0.14 cm.msec-1) and IF
(0.83 ± 0.39 cm.msec-1) were comparable. The RSI30 (p=0.47) values were also
in accordance with the above results with no differences between PIT (0.75 ±
0.32 cm.msec-1), CAT (0.69 ± 0.22 cm.msec-1), OF (0.86 ± 0.21 cm.msec-1) and IF
(0.88 ± 0.20 cm.msec-1). Finally, RSI46 (p=0.62) values also showed no differences
between PIT (0.74 ± 0.29 cm.msec-1), CAT (0.67 ± 0.25 cm.msec-1), OF (0.87 ±
0.15 cm.msec-1) and IF (0.78 ± 0.20 cm.msec-1). CONCLUSIONS: General athletic
ability as measured using RSI and VJ kinetics are similar between playing positions
in this sample of high school baseball players. This could be attributed to lack
of or varied physical and athletic maturity in these young athletes. PRACTICAL
APPLICATIONS: RSI may be a time efficient tool for measuring athletic abilities in
sport settings. Research is needed to determine differences amongst elite levels
athletes and whether RSI scores relate to sport specific skills such as base running
speed, agility, and reactive quickness. Poster: 35
POWER DEVELOPMENT COMPARISONS BETWEEN POWER CLEAN
VARIATIONS AT DIFFERENT RELATIVE LOADS
T. J. Suchomel1, G. A. Wright2
1
East Tennessee State University, 2University of Wisconsin-La Crosse
*Award Eligible - Outstanding Doctoral Student Poster Presentation
Exercise and load selection is vital to strength training programs. When
implementing the power clean and its variations, there is no exception. Despite
being commonly used exercises, little research has compared the power
development between power clean variations. PURPOSE: To compare the peak
power (PP) produced by power clean variations at different relative loads.
METHODS: Subjects included 17 athletic men with a minimum of 2 years of training
experience with the hang clean (HC) but no previous competitive lifting experience.
During 3 separate testing sessions, each subject completed 3 maximal repetitions
each of either the HC, jump shrug (JS), or high pull (HP) at relative loads of 30%,
45%, 65%, and 80% of their 1 repetition maximum (1RM) HC on a force platform.
Thus, the comparison between exercises was done with equated absolute loads.
Vertical ground reaction forces of the lifter plus bar system were taken directly
from the force platform and PP was calculated using forward dynamics. The PP
produced during the HC, JS, and HP at each load was averaged and 12 individual
PP data points (HC30, HC45, HC65, HC80, JS30, JS45, JS65, JS80, HP30, HP45,
HP65, and HP80) were compared. A one-way repeated measures ANOVA was
used to compare the differences between the PP produced by each exercise at
each load. RESULTS: JS30 produced the greatest PP and was followed in order
by JS45, JS65, JS80, HP45, HP30, HP65, HP80, HC65, HC80, HC45, and HC30. PP
during JS30 was significantly greater than HC30 (p < 0.001), HC45 (p < 0.001),
HC65 (p < 0.001), HC80 (p < 0.001), JS65 (p = 0.007), JS80 (p < 0.001), HP30 (p
< 0.001), HP45 (p = 0.001), HP65 (p < 0.001), and HP80 (p < 0.001). PP during
JS45 was significantly greater than HC30 (p < 0.001), HC45 (p < 0.001), HC65 (p
< 0.001), HC80 (p < 0.001), JS80 (p < 0.001), HP30 (p < 0.001), HP45 (p = 0.001),
HP65 (p < 0.001), and HP80 (p < 0.001). JS65 PP was significantly greater than
HC30 (p < 0.001), HC45 (p < 0.001), HC65 (p < 0.001), HC80 (p = 0.001), HP65 (p
< 0.001), and HP80 (p = 0.001). JS80 PP was significantly greater than HC30 (p <
0.001), HC45 (p = 0.016), HC65 (p = 0.001), HC80 (p = 0.007), HP65 (p = 0.016),
and HP80 (p = 0.026). PP during HP30 was significantly greater than HC30 (p =
0.002), HC45 (p = 0.014), and HC65 (p = 0.028). PP during HP45 was significantly
greater than HC30 (p = 0.009), HC45 (p = 0.019), and HC65 (p = 0.037). No other
significant relationships between conditions existed (p > 0.05). CONCLUSIONS:
JS PP production was superior to both HC and HP PP production at all loads. In
addition, HP PP production was superior to HC PP production at all loads. It is
possible to produce as much, if not more, lower body power using lighter loads
and less technical power clean variations. PRACTICAL APPLICATIONS: The JS
and HP appear to be superior to the HC across the loading spectrum in athletic
men and should be considered as exercises that can be used to train lower body
power. Although the HC is a highly beneficial exercise, this study indicates that
the JS at all loads and the HP at loads between 30-45% 1RM HC, may provide a
superior stimulus to those being trained. A practitioner should implement the HC,
JS, and HP to complement each other in their strength training regimens in order
to provide varying stimuli to effectively train lower body power. Based on the
training goal of those being trained, various loading schemes should be used to
provide the optimal training stimuli.
Poster: 36
CHANGES IN MEDIAL GASTROCNEMIUS MUSCLE-TENDON INTERACTION WITH
AN INCREASE IN MOVEMENT FREQUENCY
J. J. McMahon1, S. J. Pearson1, P. Comfort1
1
University of Salford
Tendons account for the majority of muscle-tendon unit (MTU) lengthening and
shortening during stretch-shorten cycle (SSC) movements, which allows muscles
to operate at more effective velocities for producing large forces. It is unknown,
however, how muscle-tendon interaction changes with an increase in SSC
movement velocity. PURPOSE: To determine medial gastrocnemius (MG) muscletendon interaction across a range of SSC movement velocities in order to inform
plyometric training practice. METHODS: Resistance trained males (n=11, 27.0 ± 8.4
years, 180.8 ± 5.8 cm, 86.3 ± 10.2 kg) performed three single-leg hopping trials
on an inclined sledge at 2.0, 2.5 and 3.0 Hz in a randomized and balanced order.
Three-dimensional motion analysis, ultrasonography of MG and ground reaction
forces were collected. For each trial, five consecutive hops performed within
±5% of the prescribed frequencies were analyzed. Sagittal plane joint angles and
moments were determined via a combination of motion data, force data and
inverse dynamics. Ankle stiffness was calculated as the ratio of peak joint moment
(relative to body mass) to peak joint angular displacement. MG muscle-tendon
unit (MTU) length was determined as a function of shank segment length and joint
angle data. MG muscle length was calculated as MG fascicle length multiplied by the
cosine of the pennation angle. MG tendon length was determined by subtracting
MG muscle length from MG MTU length. The elongation and shortening phase for
each component of the MTU were determined based on the peak MTU elongation
during the contact phase. A Repeated Measures ANOVA with Bonferroni post-hoc
analysis was used to compare mean differences between frequencies (p=0.05).
RESULTS: There were significant (p<0.01) decreases in contact time (279 ± 19 ms vs.
233 ± 19 ms vs. 212 ± 15 ms) and hop height (6.3 ± 1.2 cm vs. 3.5 ± 0.9 cm vs. 1.9 ± 0.4
cm) as frequency increased. In contrast there were significant (p<0.01) increases
in ankle stiffness (0.18 ± 0.03 Nm/kg/deg vs. 0.29 ± 0.05 Nm/kg/deg vs. 0.40 ±
0.07 Nm/kg/deg) as frequency increased. The MG muscle lengthened during the
landing phase of the hops at 2.0 Hz (3.2 ± 0.8 mm), however, it shortened at 2.5 Hz
(-0.6 ± -0.2 mm) and at 3.0 Hz (-1.3 ± -0.4 mm), resulting in a significant (p<0.01)
difference between frequencies. The MG muscle shortened significantly (p<0.01)
more during the concentric phase of the hops at 2.0 Hz (6.5 ± 1.2 mm) compared
to both 2.5 (2.3 ± 0.7 mm) and 3.0 Hz (2.8 ± 0.7 mm) with no significant difference
in shortening between the two higher frequencies. Both MG tendon (19.1 ± 2.3 mm
vs. 15.1 ± 1.7 mm vs. 11.0 ± 1.9 mm) and MG MTU (22.3 ± 2.6 mm vs. 14.6 ± 2.0 mm
vs. 9.8 ± 2.1 mm) lengthening and shortening (MG tendon: 21.5 ± 3.3 mm vs. 17.0 ±
2.4 mm vs. 10.9 ± 3.0 mm; MG MTU: 28.0 ± 3.2 mm vs. 19.3 ± 2.7 mm vs. 13.7 ± 3.0
mm) significantly (p<0.01) decreased as frequency increased. CONCLUSIONS: The
MG tendon comprised the majority of MG MTU lengthening and shortening at the
higher movement velocities (i.e. ≥2.5 Hz). PRACTICAL APPLICATIONS: Performing
SSC movements at higher velocities mainly trains the series-elastic component,
whereas the neuromuscular component is trained more at lower velocities.
This study was funded by the NSCA Foundation.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 37
EFFECT OF WEIGHTED IMPLEMENT TRAINING ON BAT VELOCITY OF HIGH
SCHOOL BASEBALL PLAYERS: A PILOT STUDY
D. Szymanski1, T. Donahue1, W. Tolbert1, B. Stover1,
A. Elumalai1, M. Greenwood2
1
Louisiana Tech University, 2Texas A&M University
Success in hitting a baseball is greatly dependent upon augmenting bat velocity
(BV). Currently several weighted devices on the market claim to increase BV after
training. PURPOSE: To examine the effects of 8 weeks of sport-specific resistance
training on BV of Louisiana high school baseball players using a weighted swing
implement. METHODS: Twelve high school baseball players (age = 15.8 ± 0.94 yr,
ht = 170.7 ± 6.7 cm, wt = 70.0 ± 16.7 kg, %BF = 14.8 ± 8.4%) volunteered for this
study. Prior to training, subjects had 3 familiarization sessions with the weighted
hitting device, taking 3 x 10 swings per day. On the testing day, players took 2
x 10 warm-up swings and hit tennis balls off a batting. Then participants took 10
swings (20 seconds rest between swings) with a modified test-bat in their normal
batting stance at a baseball resting on a batting tee. BV was measured by a
Setpro-SPRT5A. After the pre-training testing session, participants were randomly
assigned to 1 of 2 training groups. The treatment group (n = 6) took swings at a 2:1
volume ratio of the weighted and standard bat while hitting tennis balls off a batting
tee. One-third of their total swings (1020 swings) were taken with a 30.5 in, 48
oz weighted device, another 1/3rd of their swings (1020 swings) were taken with
a 30.5 in, 64 oz weighted device, and the final 1/3rd of their swings (1020 swings)
were taken with their standard game bat (33 in, 30 oz) 3x/wk for 8 weeks during
the off season. The control group (n = 6) swung their standard game bat 3x/wk
for 8 weeks for the same total number of swings (3060 swings) as the treatment
group while also hitting tennis balls off a batting tee during the off season. To
determine differences between or within groups, repeated measures analyses of
variance (ANOVA) were conducted on BV. Independent samples t-tests were also
conducted to compare the 2 groups in terms of percent (%) change (post-BV
minus pre-BV divided by post-BV multipled by 100) of BV (p < 0.05). RESULTS:
Repeated measures ANOVA on BV (m/s) indicated that there were no statistically
significant differences between the groups; however, both groups made significant
improvements (treatment p < 0.001 and control p < 0.05) in BV after 8 wk of
training. Furthermore, significant differences, t (10) = -2.32, p = 0.04, in % change
in BV, pre to post-training, were observed between the 2 groups. CONCLUSIONS:
Findings suggest that swinging either a standard baseball bat or a combination of
weighted hitting devices and standard baseball bat in a 2:1 weighted to standard
bat volume ratio significantly improve BV (5.71 & 10.42%) after 8 weeks of training
for high school baseball players. Furthermore, % change increased significantly
more (4.71%) after swinging the weighted devices and standard baseball bat
compared to the standard baseball bat alone. PRACTICAL APPLICATIONS: Since
both swing protocols produced significant improvements in BV in high school
baseball players, high school coaches can choose which device and program to
implement. For best results for high school players, it is recommended to use the
weighted devices and swing protocol during the off season when players are not
competing during the in-season since the volume of total swings were taken only
from a batting tee and not during live batting practice which is a very important
aspect of being a successful hitter. ACKNOWLEDGEMENTS: Weighted devices
were provided by Bats Limited (Hewitt, TX, USA).
Poster: 38
PRELIMINARY INVESTIGATION INTO THE SUITABILITY OF AN
ALTERNATIVE FORM OF COUNTERMOVEMENT JUMP TEST
ANALYSIS FOR ATHLETE TRAINING MONITORING.
R. Gathercole1, B. Sporer2, T. Stellingwerff2, G. Sleivert2
1
University of Victoria, BC, Canada/CSI-Pacific, Victoria, BC, Canada/Sport
Innovation Centre, Victoria, BC, Canada, 2University of Victoria, BC, Canada/
CSI-Pacific, Victoria, BC, Canada
PURPOSE: The countermovement jump (CMJ) test is an athlete monitoring tool
used to examine neuromuscular (NM) function and training-effects. There is
uncertainty though as to which components of CMJ performance are the most
sensitive to training-induced changes in performance. Here we assess the suitability
of the CMJ test for the detection of induced changes in NM function, examining an
alternative form of CMJ analysis based on jump traces (aCMJ) compared to more
typical CMJ-derived measures (tCMJ). METHODS: 5 elite snowboard athletes (2M,
3F) performed 6 CMJ tests prior to and following a structured training block (~4
mo.). CMJ was evaluated using the Ballistic Measurement System (BMS; Fitness
Technology, Australia). 20 aCMJ variables, based on time, work and single points
during the jump, were analysed using custom-designed software, with raw jump
data extracted from the BMS. aCMJ variables (8 reported): Time: eccentric (EccT),
concentric (ConT), and total jump duration (TotT), percentage of time spent
eccentrically (EccT%); Work: area under force-velocity trace (FV-AUC), total
area under power-time trace (PT-AUC), PT-AUC divided by TotT (PT-AUC/TotT);
Single-point: force at zero velocity (F@0V). tCMJ variables: jump height (JH),
peak power (PP), peak velocity (PV), peak and mean force (PF, MF). ‘Outlier’
jumps were removed using standardised procedures. Coefficients of variation
(CV) were calculated for each pre and post-variable to examine whether the
variability of each variable would permit detection of training-induced changes.
RESULTS: Significant differences pre- to post-training (p value) were observed
for aCMJ variables for time (EccT: -0.11s, 0.017; TotT: -0.13s, 0.030; EccT: -5.4%,
0.002), work (FV-AUC: +994N.ms-1, 0.002; PT-AUC/TotT: +4.2watts/kg/s, 0.017)
and single-point (F@0V: +197N, 0.038). The other aCMJ and tCMJ variables were
not significantly different. CONCLUSIONS: Compared to the tCMJ variables, the
use of aCMJ variables appear better suited to the detection of training-induced
NM changes. The results of the aCMJ variables suggest that the effects of training
may be expressed as an altered CMJ movement strategy rather than an altered
CMJ output (i.e. jump height, peak power). The lack of change in PT-AUC suggests
that a similar amount of work was performed during the CMJ. However, the
improved speed and time required to perform this work indicates an enhanced
performance. PRACTICAL APPLICATIONS: These results indicate that training may
affect NM strategy and the movement performed more so than end NM output.
Consequently, training-induced NM effects may be more apparent through an
analysis of aCMJ variables, rather than more typical CMJ variables (i.e. tCMJ).
Poster: 39
EFFECTIVE MECHANICAL ADVANTAGE OF THE KNEE JOINT ACROSS
SUMAXIMAL LOADS WHILE PERFORMING THE CLEAN
K. Kipp1, C. Harris2
1
Marquette University, 2LaGrange College
An increase in the load that is lifted during a weightlifting exercise (e.g., clean)
is not always associated with a concomitant increase in torque production of
the lower extremity joints. It is possible, however, that instead of lifting heavier
weights by increasing the torque output at a joint, lifters manipulate the effective
mechanical advantage about the joint through careful control of the ground
reaction force vector. PURPOSE: To determine if an increase in lift weight is
associated with an increase in the effective mechanical advantage at the knee
joint. METHODS: Five collegiate-level weightlifters (mean±SD; mass: 105.7±14.4
kg; 1-repetition maximum (RM) clean and jerk: 127.5±24.9 kg) performed cleans
at 65, 75, and 85% of their 1-RM while a motion analysis system was used to
make kinematic measurements of the right-side hip, knee, and ankle joints while
a force plate was used to make kinetic measurements. These measurements
were combined in an inverse dynamics procedure, which was used to calculate
net internal knee joint torques. The effective mechanical advantage of the knee
extensor muscle group was calculated as the instantaneous ratio between the
moment arm of the patellar tendon about the knee joint and the moment arm
of the ground reaction force vector about the knee joint. The maximum effective
mechanical advantage observed during the entire lift phase of the clean was then
extracted and used for analysis. Non-parametric statistics were used determine
the change in maximum effective mechanical advantage across the lift weights.
The statistical significance level was set an alpha-level of 0.05. RESULTS: The
effective mechanical advantages at the knee joint were 1.25±0.45 at 65% of 1-RM,
1.43±0.50 at 75% of 1-RM, and 1.45±0.50 at 85% of 1-RM. The effective mechanical
differed significantly between the 65% and 85% lift (p = 0.034). There was also
a trend for a different effective mechanical advantage between 65% and 75%
(p = 0.051). CONCLUSIONS: As lift weight increased from 65% to 85% of 1-RM,
lifters also increased the effective mechanical advantage of the knee extensor
muscle group. The increase in effective mechanical advantage would allow lifters
to generate greater ground reaction forces without a concomitant increase in the
torque production and muscular effort of the respective muscle group. This would
suggest that an increase in lift weight is partially associated with an increase in
efficiency of knee joint mechanics. PRACTICAL APPLICATIONS: Lifting heavier
weights appears to be partially related to the effective mechanical advantage
at the knee joint. Since a change in effective mechanical advantage affects lift
efficiency it may present a technical element that could be used by coaches and
sports scientists to monitor and improve weightlifting performance.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 40
THE RELATIONSHIP BETWEEN FAT-MASS, FAT-FREE MASS,
AND HEART RATE VARIABILITY
R. L. Herron1, S. J. Carter1, H. Williford2, M. Esco2
1
The University of Alabama, 2Auburn University Montgomery
Heart rate variability (HRV) is a non-invasive measure of cardiovascular autonomic
modulation and is growing in popularity as an important tool to monitor the
physiological outcomes associated with exercise training. Researchers have
suggested a strong association between body composition and HRV, though the
extent of this relationship remains unclear. To date, limited research has examined
the link between fat-free mass (FFM) and HRV. PURPOSE: The purpose of this
study was to determine the extent of variation in HRV that could be accounted
for by FFM and fat-mass (FM). METHODS: Fifty adult men (22 ± 3 yr) participated
in this study. Each subject rested in the supine position while HRV was recorded
for a 5-min period. To measure HRV, the frequency domain was used to transform
the electrocardiogram into a power spectrum. The normalized area under the
high-frequency (0.15 to 0.40 Hz) component was recorded and analyzed as a
marker of parasympathetic modulation. The sum of skinfolds (7 sites) was used
to determine FM and FFM. Pearson product moment correlation procedures were
used to assess the relationship between HRV (i.e., high-frequency, HF) and body
composition (i.e., FM and FFM) parameters. RESULTS: Data are presented as
means and SD, HF 40.0 ± 19.2%, FM 9.9 ± 4.8 kg, and FM 72.6 ± 7.6 kg, respectively. The results indicated that HF significantly correlated with FFM (0.32, P < 0.05), but
not with FM (-0.18, P > 0.05). CONCLUSIONS: These data suggest a significant
relationship between FFM and HRV. Interestingly, a significant correlation between
FM and HRV was not present. PRACTICAL APPLICATIONS: While the results
demonstrate a significant relationship between FFM and HRV, more research is
needed. However, clinicians should continue to emphasize resistance training
as part of a well-balanced program as a means to increase FFM and possibly
improve HRV.
Poster: 41
RELATIONSHIPS BETWEEN ATHLETIC PERFORMANCE AND MEASUREMENTS
RELATED TO CORE STABILITY IN YOUNG ATHLETES
A. Waldhelm1, L. Li2, D. Heard3
1
University of the Incarnate Word, 2Georgia Southern University,
3
Athletic Republic, Covington, LA
PURPOSE: Core stability training is a common intervention used to help improve
athletic performance. It is hypothesized, a strong and stable core will allow for
efficient transfer of power from the ground through the trunk and to the upper
extremities which will improve sports performance. Unfortunately, few studies
have been performed to investigate the association between athletic performance
and core stability. Therefore, the purpose of our study was to identify relationships
between athletic performance tests and measurements associated with core
stability (MACS) amongst young athletes. METHODS: Twenty-one individuals (12 F
/ 9 M, 13.4 ± 1.2yr) who had not suffered an orthopedic injury in the past year were
recruited from a local sports training facility. The participants provided informed
consent as approved by the local Institutional Review Board, prior to testing. The
nine athletic performance tests included the vertical jump, 20-yd pro shuttle run,
DSQ 1234, DSQ 1432, bilateral single leg long jump (SLLJ), 10 and 20-yd dash,
and the Cunningham and Faulkner anaerobic capacity test. The 21 MACS were
grouped into five different categories related to strength, muscular endurance,
flexibility, motor control and function. One-tailed Pearson correlation coefficient
(CC) analyses were performed to estimate the relationship between athletic
performance tests and MACS. RESULTS: Overall, the relationships between the
athletic performance tests and the MACS ranged from low, r = .002, to high, r =
.761 correlations. Correlations coefficients between the vertical jump and MACS
ranged from r = -.047 to r = .559, and the strongest relationship observed with
right hip abduction strength. CCs ranged from r = .034 to r = -.682 between the
shuttle run and the MACS, and the highest correlation was with the right single
leg side plank. CCs between the DSQ 1234 and the MACS ranged from r = -.014
to r = -.418 with the strongest and only significant correlation occurring with the
left stork test. The DSQ 1432 and right hip abduction strength had the strongest
relationship amongst the MACS with CCs ranging from r = -.112 to r = -.575. The
right SLLJ and MACS had CCs ranging from r = .105 to r = .728 with right hip
abduction strength having the strongest relationship. CCs ranged from r = .039 to
r = .533 between the left SLLJ and MACS, with right single leg side plank having
the strongest relationship. CCs ranging from r =-.006 to r = -.659 between the 10yd dash and the MACS, and the strongest relationship was associated with the left
isometric single leg press. The 20-yd dash had only one significant relationship,
right hip adduction strength, and CCs ranged from r = .005 to r = -.545. Last,
relationships between the Cunningham and Falkner test, which only had 10
participants, and the MACS ranged from r = .002 to r = .761 with the strongest
relationship occurring with trunk extension endurance. CONCLUSIONS: The overall
relationships between the athletic performance tests and the MACS ranged from
very low to high correlations and varied between performance tests. PRACTICAL
APPLICATIONS: The results indicate different components of core stability may
play a role in different athletic performance of young athletes. Therefore, exercises
which improve core stability should be included in a sports training program
Poster: 42
REPEATABILITY OF 3D MARKERLESS MOTION CAPTURE AND HOW IT COULD
AFFECT BETWEEN-SESSION TESTING
D. Wassom1, A. C. Fry2, N. Moodie3
1
Dynamic Athletics, 2The University of Kansas,
Human Performance Laboratory, Lawrence, KS, 3Rockhurst University
PURPOSE: When tracking people using motion capture technology it is important
to know that when test you willing have repeatable results. It has been shown that
marker based motion capture has variability between-session testing with a large
part of the problem due to marker placement error. Being able to remove that
variable potentially could help between-session testing. The purpose of this study
was to test the repeatability a 3D markerless motion capture system. METHODS:
one subject did 16 controlled squats in the 3D markerless motion capture space
while also being videoed. A standardized box was used to control the depth of
the squat as well as standardized distances to the box and distance between feet. Collections were done on two separate days and additionally before each take,
the subject’s biomechanical skeleton was recreated. The software specifically
identified the peak joint angle of the squat as the indicator of when values were
measured. The subject paused at the bottom of the squat before rising to allow
for proper time for videos to be taken. The left knee angle was calculated at
that point. The repeatability of the 3D markerless motion capture system was
then compared to an industry accepted video standard. RESULTS: Coefficient
of multiple determinations (CMD) was used to statistically evaluate the 3D
Markerless motion capture system and video. The 3D markerless motion capture
system showed an R2 equal to (.7712), while video had an R2 equal to (.7692). When comparing 3D markerless motion capture to video the R2 value was
(.9808). CONCLUSION: 3D Markerless motion capture is statistically repeatable,
and is as repeatable as an industry standard. Further research needs to be done to
compare 3D markerless motion capture to 3D marker motion capture. PRACTICAL
APPLICATION: 3D markerless motion capture has the potential to remove human
error from multi-session testing. With the ultimate goal of potentially being able
to improve repeatability across multi location data sets.
Poster: 43
INFRASPINATUS STRENGTH ASSESSMENT: CORRELATIONS BETWEEN FORCE
PRODUCTION AND EMG ACTIVITY
D. Witt1, N. Talbott1, E. Thompson1, S. Belen1
1
University of Cincinnati
Purpose: Assessment of the strength of the infraspinatus is a common component
of the examination of athletes with shoulder pain and dysfunction. Important
for stabilizing the humeral head during overhead movements and for externally
rotating the humerus during shoulder elevation, the infraspinatus is active during
multiple motions that are required by athletes during training and competition. One common method for testing and eventually exercising the infraspinatus
is resisting external rotation with the arm at the side. For some athletes, the
infraspinatus may also be exercised and assessed with the arm elevated to ninety
degrees, a position more closely related to the overhead requirements of various
sports. Determining the force production and the related electrical activity of
the infraspinatus in these two positions will provide information that can assist
in the identification of the most appropriate methods for maximizing force in
this muscle. The purpose of this study is to determine if the infraspinatus force
production and electrical activity significantly change when the shoulder is moved
from a neutral position to a position of ninety degrees of elevation in the scapular
plane (scaption). Methods: Ten shoulders from five healthy subjects were tested
using electromyography (EMG) and dynamometry. Surface electrodes were
applied to the infraspinatus two inches inferior to the mid- third of the spine
of the scapula. With the subject sitting, the shoulder was placed in a neutral
position and resting EMG recorded. Measurements were repeated as the subject
performed a maximal isometric external rotation contraction against a stable
dynamometer and, after resting, a maximal isometric external rotation contraction
against manual resistance applied through a hand held dynamometer. Force was
recorded during each contraction and the corresponding EMG activity stored. The
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
process was repeated with the shoulder in a position of 90 degrees of elevation
in the scapular plane. All measurements and images were taken three times. EMG data was filtered and rectified with mean and maximal activity recorded
during the mid three seconds of the contraction. Results: Force production was
significantly greater in the neutral position than in a position of 90 degrees of
scaption. However, EMG activity was not significantly different in the two test
positions. During maximal resistance against stable resistance with the arm in
a neutral position, mean EMG activity of all subjects averaged .364mV (SD=.14)
which was not significantly different from the mean EMG activity of .280mV
(SD=.09) recorded in the elevated position. Force was not significantly correlated
with EMG activity in either position. Conclusions: The application of maximal
force significantly changes with shoulder position but is not significantly related
to changes in EMG activity. Practical Applications: If maximal force production
is a goal, it would be more advantageous to exercise the infraspinatus in a neutral
position than in a position of scaption. Monitoring infraspinatus EMG activity is
not supported as a measurement of maximal force production. Poster: 44
INFLUENCE OF OPPOSITION ON GAME PLAY INTENSITY DURING WOMENS
NATIONAL LEAGUE FIELD HOCKEY
A. White1, N. MacFarlane1
1
University of Glasgow
INTRODUCTION: Anecdotally, teams are thought to drop the intensity of game
play when competing against lower level opposition and vice versa. This study
aims to demonstrate whether this is true in national league field hockey. METHODS:
A mid-placed team in the first division of a national field hockey league was
selected for this observational study. 16 female field hockey players (age range
19-35 yrs) were studied (giving seventy-eight player analyses over eight games).
Playing activity was recorded using a 5-Hz global positioning system. Markers of
game play intensity (i.e. distance covered, meterage, player load, efforts in speed
zones, percentage time in speed zones and distance covered in speed zones) were
compared in competitive matches. League position after 8 matches in the current
season determined opposition team ranking. RESULTS: This study shows Pearson
correlation coefficient and regressions analysis results for all parameters. Distance,
meterage and player load were all negatively correlated with opposition ranking.
R-squared values for accelerations over 4m.s-2 and work-to-rest ratio were both
greater than 50% and reached statistical significance (p < 0.05). DISCUSSION:
These data show distance covered, meterage, player load, accelerations over 4m.s2
and work-to-rest ratio are influenced by the ranking of the opposition during
competition. Where the ranking of the opposition is lower then the intensity
of game play in the higher ranking team is reduced and vice versa. PRACTICAL
APPLICATIONS: In team sports, a significant portion of training load is associated
with game play during the playing season (and perhaps more so in amateur
sport). These data suggest that higher ranked teams may drop their intensity
of game play against lower ranking opposition and compromise their estimated
training load during that micro-cycle. These data are important for coaches and
conditioning practitioners to consider when periodizing training throughout a
competitive season. Poster: 45
COMPARISON OF A HYDRAULIC RESISTANCE TRAINING SYSTEM
AND TYPICAL MUSCULAR STRENGTH AND CARDIOVASCULAR
TRAINING PROTOCOLS IN WOMEN
L. Carson1, P. Falcone1, C. Tai1, M. Kim1, J. Moon1
1
MusclePharm Sports Science Center Research Institute
Many innovative exercise devices are emerging from the traditional treadmill,
bike, and weights. Some systems, such as a hydraulic resistance platform (HRP),
strive to provide a cardiovascular benefit while adhering to a resistance exercise
protocol. It is important to determine if these types of devices can provide the same
cardiovascular benefit or caloric expenditure as traditional workouts. PURPOSE: The purpose of this investigation is to determine the caloric expenditure and
anaerobic demand during a typical 30 minute workout using the HRP compared
to a standard strength training session and typical cardiovascular training sessions
lasting around 30 minutes. METHODS: This study followed a repeated measure
design and consisted of 11 physically active women (30 +/- 4yrs; 66.5 +/- 2in;
137.5 +/- 13.5lbs.) Every participant completed four separate exercise protocols
at least 48 hours apart. Each protocol lasted 30 minutes and were performed in
the following order: treadmill, elliptical, HRP, and weights. Subjects completed
a choice reaction time protocol as a warm up and cool down using two reaction
time devices. The metabolic data were captured by a portable metabolic cart.
The outcomes of interest were the rate of perceived exertion , heart rate, grams
of carbohydrates and fat burned per minute, and total calories burned per
minute. RESULTS: Regarding rate of perceived exertion, HRP (16.3 +/- 1.3) was
significantly (p<0.05) higher than treadmill (11.4 +/- 1.0), elliptical (11.5 +/- 1.2) and
weights (13.1 +/- 2.3). Heart rate was significantly (p<0.05) higher in HRP (136.8
+/- 15.5 bpm) than weights (107.5 +/- 18.3 bpm), but not significantly different
compared to treadmill (132.6 +/- 5.1 bpm) or elliptical (132.2 +/- 4.4 bpm). The
average grams of carbohydrate burned were significantly (p<0.05) higher in
HRP (1.7 +/- 0.4 g/min), compared to treadmill (1.2 +/- 0.3 g/min) and weights
(1.0+/-0.3 g/min), but not significantly different than elliptical (1.3+/-0.3 g/min).
The grams of fat burned per minute were significantly (p<0.05) higher in HRP
(0.09+/-0.03 g/min) than weights (0.02+/-0.01 g/min), but were significantly
(p<0.05) lower compared to treadmill (0.3+/-0.1 g/min), elliptical (0.3+/-0.1 g/
min). Total calories burned per minute were significantly (p<0.05) higher in HRP
(7.6 +/- 1.4 kcal/min) than weights (4.3+/-1.2 kcal/min), but not significantly
different compared to treadmill (7.5 +/- 0.8 kcal/min) and elliptical (7.9+/-0.8 kcal/
min). CONCLUSIONS: Though the rate of perceived exertion was increased using
an HRP, heart rate, grams of carbohydrates, grams of fat and total calories were
not significantly different compared to running or elliptical training lasting around
30 minutes. PRACTICAL APPLICATIONS: An exercise protocol using a hydraulic
resistance system may provide cardiovascular benefits similar to a typical cardio
workout, as well as the skeletal and muscular benefits of a typical weight training
protocol. ACKNOWLEDGEMENTS: This investigation was supported by funding
from Surge Performance Training Inc.
Poster: 46
LONGITUDINAL TRACKING OF MAXIMUM SQUAT, BENCH PRESS, AND POWER
CLEAN PERFORMANCE IN MALE HIGH SCHOOL ATHLETES
J. A. Bush1, J. McFarland2, R. Herman2, N. A. Ratamess1,
J. Kang1, S. Klei1, A. D. Faigenbaum1
1
The College of New Jersey, 2Hillsborough High School, NJ
A growing number of young athletes are resistance training in school- and
community-based programs. While regular participation in age-related resistance
training programs can enhance muscular fitness, only limited data are available
on longitudinal changes in strength and power in adolescent athletes. Moreover,
the use of 1 repetition maximum (RM) testing to assess muscular fitness in
young athletes remains contentious. PURPOSE: To assess the maximal muscular
fitness profile of healthy adolescent athletes who participated in a strength
and conditioning program over a 3-yr period. Additionally, we assessed the
level of self-reported injuries during these 3 yrs. METHODS: Performance data
from fifteen male high school athletes (age range 15-18 yr) who participated
in football and track and field were analyzed in this retrospective longitudinal
study. Each subject’s 1 RM data on the squat, bench press and power clean
exercises which were assessed under qualified supervision during the offseason
phase of training during a 3 yr study period (Y1, Y2, Y3) were used for analysis.
Subjects participated in a periodized strength and conditioning program about
3 to 4 times/wk for 40 wks/year. The supervised training program focused on
enhancing technical proficiency on various weightlifting movements, plyometric
drills and resistance training exercises, and the training intensity gradually
progressed to 70-95% 1 RM depending on the phase of the training cycle and
sport participation. Dependent variables of strength and power over Y1-Y3 were
analyzed using a GLM regression with pair-wise comparisons across Y1-Y3.
Significance was set at p<0.05. RESULTS: Youth were considered of good health: There was a significant (p=0.00) increase (+19%, +13%) in 1 RM bench press from
Y1-Y3 & Y2-Y3 respectively with no significant change from Y1-Y2 (p=0.06). There
was a significant (p=0.02) increase (+16%, +15%) in 1 RM squat from Y1-Y3 & Y2Y3, respectively, with no change from Y1-Y2. There was a significant (p=0.01)
increase (+7%, +17%, 10%) in 1 RM power clean Y1-Y2, Y1-Y3, & Y2-Y3, respectively. No injuries resulting from 1RM testing or resistance training were reported.
CONCLUSION: Regular participation in a long-term strength and conditioning
program that includes periodic 1 RM assessments can be a safe and effective
activity for adolescent athletes provided the program is characterized by qualified
instruction and periodized training. While there was a significant increase in
strength and power over the 3-year training period, performance gains were
most apparent during the second and third year of training which followed the
initial phase of training that focused on developing movement pattern efficiency. Data from this longitudinal study provide useful information for youth coaches
and pediatrics researchers who monitor training-induced changes in muscular
fitness and design long-term resistance training programs for young athletes.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 47
CONSTRUCT VALIDITY OF TRADITIONAL AND ALTERNATIVE METHODS OF
SCORING PULL-UPS
J. Clemons1, C. Thompson2, J. Guillory3, E. Roberts3, K. Buteau3
1
Department of Kinesiology, University of Louisiana at Lafayette, 2University of
Louisiana at Lafayette, 3University of Louisiana at Lafayette
PURPOSE: The purpose of this investigation was to examine the construct validity
of three different methods of scoring pull-ups (PU): the traditional method of
counting only full range of motion (ROM) pull-ups, fractional PUs (i.e., 0.25, 0.5, 0.75
of the ROM) using the elbow angle as a reference but without a goniometer, and
PU work (NM). METHODS: Seventeen college age males (23.5 yrs.±7.91) enrolled
in university weight training classes volunteered to participate. The fractional PU
method credited participants on the last partial PU by awarding 0.25 points if
an estimated elbow angle < 180° but > 95° was reached. A half point (0.5) was
given for elbow angles between 95° and 85° of elbow flexion (i.e., 90° ± 5°) and
0.75 points if elbow angles, at the point of failure, were less than 85° but short
of lifting the chin above the bar. Four independent testers scored the fractional
PU to determine if inter-rater reliability might be achieved. Only one PU test was
necessary in that traditional and fractional PU scores were derived simultaneously.
Both traditional and fractional work were computed using the formula: PU Work in
NM = #pull-ups · vertical distance in m · body mass · 9.81). Pearson correlation was
used to compare scores acquired using each method to three commonly accepted
criterion measures: absolute strength (i.e., a one repetition maximum [1RM] lat
pull down), relative strength (1 RM · Body Mass-1) and relative muscle endurance
(i.e., repetitions to failure at 75% of the 1RM). Inter-rater reliability for the fractional
method was examined using four independent testers with data analyzed using
Intraclass Correlation (ICC). The alternative hypotheses to the null were two
tailed at a Bonferroni adjusted alpha level of 0.0042 based on 12 relationships of
interest. The PU, 1RM and 75% 1RM tests were separated by no less than 4 days and
no more than a week. The 1 RM attempts were preceded by two unsupervised sets
of 50% and 60-80% of a participant estimated 1RM. Independent warm-ups were
used for the remaining tests. RESULTS: Inter-rater reliability for the fractional
scoring method was excellent (ICC = 0.999). The weakest relationships were
between the 1 RM and traditional and fractional scoring methods (r =0.28, p.
= 0.27); however, both correlated strongly with relative strength (i.e., 0.86; p
= 0.0000). PU fractional work showed a moderate relationship (r = 0.50) with
the 1RM; however, it failed to be significant at the adjusted alpha level. Both PU
work methods correlated strongly with relative strength but dropped to 0.82 (p <
0.0001). The strongest relationship with the 1RM was found using linear regression
with body mass and fractional PU work used as co-predictors (R = 0.87; p <
0.0001): 1 RM Lat Pull Down = (Pull-up fractional work · 0.004) + (0.733 · Body
Mass) + 20.672; SEE = 5.727 kg. CONCLUSIONS: Traditional and fractional PU test
scores are valid measures of relative strength; however, they are poor indicators of
absolute strength. When pull-up scores are transformed to work; the relationship
strengthens with the 1RM, but the shared variance rises to only 25%. Traditional
and fractional work; however, when considered along with body weight results in
R values of 0.85 and 0.86, respectively (p < 0.0000) and predictions that are not
significantly different from the actual 1RM. PRACTICAL APPLICATIONS: Properly
scored and interpreted, PU tests can be valid estimates of either absolute and/or
relative strength.
Poster: 48
PERFORMANCE MOUTHPIECE IMPROVES X-FACTOR IN YOUNG
AND OLD GOLFERS
W. D. Dudgeon1, D. Garner1, E. McDivitt1, B. Hepner1, T. P. Scheett2
1
No MP), and Max Hip Speed (p=0.002, 461.0 +/- 46.7, MP vs 449.9 +/- 43.3, No
MP). Only with Total Hip Rotation (p=0.056, 108.8 +/- 14.2, MP vs 106.9 +/- 13.9,
No MP) was there a trend for significance with the recreational group. There
were no differences in either group individually or combined regarding Total
Shoulder Rotation, Hip Rotation at Top, and Max Shoulder Speed. Conclusion:
Data suggests that the mouthpiece may be helpful to improve parameters of golf
performance in collegiate athletes.
Poster: 49
COMPARISON OF A HYDRAULIC RESISTANCE TRAINING SYSTEM AND TYPICAL
MUSCULAR STRENGTH AND CARDIOVASCULAR TRAINING PROTOCOLS IN MEN
P. Falcone1, L. Carson1, C. Tai1, M. Kim1, J. Moon1
1
MusclePharm Sports Science Center Research Institute
Strength training and cardiovascular training are two essential components
of a well-rounded exercise regimen; however, these two types of exercise are
traditionally performed separately. Some new technologies have sought to provide
a cardiovascular benefit while using resistance training methods. PURPOSE: The
purpose of this study was to determine the caloric expenditure and anaerobic
demand during a 30 minute workout using a hydraulic resistance system (HRS),
compared to a standard strength training session and typical cardiovascular
training sessions lasting around 30 minutes. METHODS: Using a repeated withinsubjects design, nine recreationally trained men (25+/-7 years; 181.6+/-7.6 cm;
86.6+/-7.5 kg) completed four exercise sessions lasting around 30 minutes each.
Metabolic data were measured with a mobile metabolic system. On the first day
of testing, subjects ran on a treadmill at 70% maximum heart rate for 30 minutes.
Before and after the running session, subjects performed a moderate warm-up
and identical cool-down session on two reaction time devices. Subjects were also
tested for their 1RM values and were familiarized with the HRS (Surge 360). The
next three sessions consisted of the same warm-up and cool-down sessions, as
well as these three training sessions for 30 minutes in the following order: bike at
70% maximum heart rate, HRS, and strength training with 3 sets of 6 exercises at
70% 1RM. Food intake and exercise were identical 48 hours prior to each testing
session. Variables analyzed were heart rate, rate of perceived exertion, calories
burned, fat grams, and carbohydrate grams. RESULTS: The HRS significantly
(p<0.05) increased calories burned per minute (12.62+/-2.36 kcal/min) compared
to treadmill (9.48+/-1.30 kcal/min), bike (9.23+/-1.25 kcal/min), and weights
(8.83+/-1.55 kcal/min). Heart rate also significantly increased (p<0.05) on the
HRS (156.0+/-9.3 bpm) compared to treadmill (137.2+/-4.6 bpm), bike (138.1+/5.9 bpm) and weights (137.7+/-15.8 bpm). The rate of perceived exertion was
significantly (p<0.05) higher with the HRS (15.8+/-1.9) compared to the treadmill
(9.9+/-1.8), bike (10.9+/-1.2) and weights (12.8+/-2.3). The grams of carbohydrate
burned per minute were significantly (p<0.05) higher with the HRS (2.98+/-0.59 g/
min) compared to the treadmill (1.74+/-0.44 g/min), bike (1.97+/-0.45 g/min) and
weights (2.15+/-0.40 g/min). CONCLUSION: The HRS significantly increased total
calories burned, grams of carbohydrate burned, heart rate and rate of perceived
exertion in men, compared to typical cardio workouts (running or cycling) and a
weight training lasting around 30 minutes. PRACTICAL APPLICATIONS: An exercise
protocol using a hydraulic resistance system may provide the cardiovascular
benefits of a typical cardio workout as well as the skeletal and muscular benefits
of a typical weight training protocol. ACKNOWLEDGEMENTS: This investigation
was supported by funding from Surge Performance Training Inc.
Poster: 50
VALIDITY AND RELIABILITY OF CRITICAL STROKE RATE DURING UPPER-BODY
ERGOMETRY ESTIMATED FROM A THREE-MINUTE ALL-OUT EXERCISE BOUT
D. H. Fukuda1, K. L. Kendall2, A. E. Smith-Ryan3,
R. P. Hetrick4, M. E. Wray5, J. R. Stout6
The Citadel, 2College of Charleston
Introduction: Jim McLean’s “X-Factor” is a metric used by golfers and instructors
to gauge separation of the hips and shoulders at the top of the backswing. It
has been shown that a greater X-Factor results in greater club head velocity. Fitness components such as flexibility, stability, and core strength are the major
contributing factors in loading certain torso muscles to maximize the torso-pelvic
separation. The Armourbite lower mouthpiece (MP) has been shown to positively
affect many aspects of human performance, thus it may influence the X-Factor.
Purpose: The purpose of this study was to determine the effects of Armourbite
MP use on the X-Factor. Methods: Ten collegiate male golfers (20.9±0.8 yrs.) and
14 recreational golfers (30.6±7.0 yrs.) performed 10 drives (5 with and 5 without
MP) with random treatment order while wearing the iClub Motion Capture System
which was integrated to a PC providing results from each swing. Results: The
collegiate golfers had significant differences in X-factor (p=0.02, 41.8 +/- 7.5,
MP vs 40.4 +/- 7.5, No MP), Max X-Factor (p=0.03, 45.6 +/- 9.1, MP vs 43.9 +/8.5, No MP), Shoulder Rotation at Top (p=0.03, -90.0 +/- 7.1, MP vs -87.2 +/- 5.9,
3
1
Creighton University, 2Georgia Southern University,
University of North Carolina Chapel Hill, 4Fitness One,
5
Lifetime Fitness, 6University of Central Florida
A three-minute “all-out” exercise test (3MT) has recently shown to provide
values similar to the traditional multi-trial approach when estimating critical
power during cycling and rowing. The critical power concept, which highlights
the work-time relationship, has also been applied to swimming and table tennis
to determine critical stroke rate (CSR), or the frequency value at which exercise
can be maintained for an extended period of time with minimal fatigue. Limited
research exists regarding the work-time relationship during upper body dominant
exercise. Furthermore, the determination of CSR has yet to be examined during
a 3MT. PURPOSE: To examine the validity and reliability of CSR during upperbody ergometry using a within subject, repeated measures design. METHODS:
Fourteen recreationally active participants (mean±SD; age: 22.14±2.85yrs;
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PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
height: 177.09±6.57cm; weight: 85.68±13.56 kg) completed three testing visits.
All testing was conducted using an upper-body ergometer (SkiErg, Concept2,
Inc., Morrisville, VT) with a damper setting of four, equivalent to a drag factor
of approximately 66. Each testing session was separated by 24-48hrs. Visit 1
and Visit 2 included separate 3MT sessions to determine the average stroke
rate (strokes per minute; spm) over the final 30s of exercise (Visit 1: CSR3MT1;
Visit 2: CSR3MT2). Visit 3 consisted of three time trials completed in a single
day at distances of 300m, 650m, and 1000m to estimate CSR using linear (total
strokes vs. time; CSRLIN) and non-linear (time vs. stroke rate; CSRNL) regression
models. Repeated measures analysis of variance, with post hoc testing, was used
to determine differences in CSR during Visits 1-3, as well as the average stroke
rate during 30s intervals of the 3MTs. The intraclass correlation coefficient (ICC),
standard error of measurement (SEM), p- values were used to assess the reliability
of CSR3MT1 and CSR3MT2. RESULTS: Estimates of CSR3MT1 (45.6±6.5spm),
CSR3MT2 (45.0±7.0spm), CSRLIN (47.2±6.6spm), and CSRNL (44.5±5.6spm)
were not significantly different (p=0.370). The stroke rate during the Visit 1 3MT
decreased from the initial 0-30s interval (~60.7spm) until the 120-150s interval
(46.4spm), and remained constant through the final 150-180s interval (45.3spm).
The stroke rate during Visit 2 decreased after the initial 60s (0-30s: 60.7spm;
30-60s: 57.7spm) and remained constant through the 60-150s intervals, then
decreased further during the final 150-180s interval (44.7spm). The ICC, SEM,
p-values for CSR from the 3MTs were 0.774 3.21spm, and 0.645, respectively.
The time trial durations from Visit 3 were 64.3±3.2s for 300m, 153.4±10.9s for
650m, and 248.2±77.1s for 1000m. CONCLUSION: The estimation of CSR from
an upper-body ergometry 3MT demonstrated concurrent-validity when compared
to the traditional multi-trial method. Furthermore, CSR estimation from a single
exercise bout demonstrated moderate reliability and a SEM that was ~7% of the
mean CSR values. Further research is needed to determine if three minutes is
the appropriate duration of all-out exercise to produce steady-state stroke rate
values. PRACTICAL APPLICATIONS: The calculation of CSR during upper-body
exercise using the 3MT may be useful in the assessment of athletes (cross-country
skiing, combat sports, sailing), those with adapted exercise needs (wheel-chair
bound, disability), and those with limited mobility (rehabilitation, overweight/
obese). ACKNOWLEDGEMENTS: Concept2, Inc. supplied the SkiErg used in this
investigation.
Poster: 51
USING THREE-MINUTE STEP TEST TO PREDICT MAXIMAL OXYGEN
CONSUMPTION IN OLDER ADULTS
C. Lee1, H. Huang2, Y. Kuo2, M. Lee3, C. Cheng4
Center for General Education, National Sun Yat-sen University, 2Department
of Physical Education / National Taiwan Normal University, 3Department of
Recreational Sports Management / Yu Da University, 4Department of Athletic
Performance, National Taiwan Normal University
1
BACKGROUND: Some studies have examined the 6-minute walk test, as a common
measurement in cardiorespiratory fitness, but few studies have investigated the
cardiorespiratory capacity and physiological responses in the relation to the
3-minute step test for older adults. PURPOSE: To investigate the relation between
maximal oxygen consumption (VO2max) and physiological responses of the
3-minute step test (3MST) for older adults. METHODS: Forty healthy participants
(20 males and 20 females, age: 68±6 yrs) without disability, or any cognitive
barriers. The participants completed this randomized and counterbalanced
experimental design, which included the 3MST (a step cadence for 20 times/
minute and step heights for 20 cm and 25 cm), and the graded exercise test on the
treadmill. A correlation between heart rate and VO2max was determined by Pearson
correlation coefficient, and the predictive formula of VO2max was determined by
linear regression analysis. To predict fitness index was using the 3MST. RESULTS:
VO2max were 26.6±4.1 and 27.8±5.6 ml/kg/min in female and male, respectively.
There was a significantly positive correlation, and coefficient between VO2max and
25 cm step test in peak oxygen consumption (r = 0.55, p < 0.05) and in peak heart
rate (r = 0.36, p < 0.05), but there was not a significantly correlation between
VO2max and fitness index from HRrecovery after 3MST (r = -0.18, p > 0.05). Linear
regression analyses identified that 3MST can explain only 1% of the HR recovery
with a moderate standard error of estimate (~4.8%); however, the different stages
of heart rate during the 3MST can explain 36% and 40% variance for the VO2max with
step height 20 cm and 25 cm, respectively. CONCLUSIONS: Predicting the VO2max
from HRrecovery after the 3MST might be a lower explanation of the variation
in older adults (> 65 years), thus indicating the absence of a true physiological
cause-effect relationship. PRACTICAL APPLICATIONS: We suggested that 3MST
was not a good method for estimating VO2max, and increase in sample would be
necessary in the further study. ACKNOWLEDGEMENTS: We would like to thank
all participants for their effort in the study. The study was supported by grant of
NSC100-2410-H-412-007.
Poster: 52
PERFORMANCE ANALYSIS OF PROFESSIONAL RUGBY UNION USING GLOBAL
POSITIONING SYSTEMS AND INTEGRATED ACCELEROMETRY
C. McLellan1, S. Coad1, D. Marsh2, M. Lieschke2, B. Gray1
1
Bond University, 2Queensland Reds Rugby Union
Professional Rugby Union (RU) match-play encompassing repeated bouts of
high intensity exercise, frequent blunt force trauma associated with high intensity
impacts experienced by players during match-play collisions that is separated by
periods of low-intensity activity. Quantification of repeated high intensity running
that includes rapid acceleration (>2.5 m.s-2) and sprinting efforts (> 22 km·h-1), and
repeated high intensity impacts (> 8.0 G), provides insight into the characteristics
of competitive performance that can be used to examine the acute and short
term post-match fatigue profile of players. Global Positioning Systems (GPS)
and integrated tri-axial accelerometry are currently the predominant portable
match-play analysis system used in elite Rugby to examine the neuromuscular
and physiological demands of competition. PURPOSE: To determine the effect
of repeated high intensity impact on high intensity running performance in elite
RU match-play. METHODS: Five (5) elite RU players whom competed in the
2012 Super Rugby premiership were monitored for the regular season period of
match-play using GPS receivers and integrated accelerometry presenting 55 data
sets for analysis (backs n = 34, forwards n = 21). Data was categorised in 1st and
2nd halves of match-play. Correlation analyses were conducted to investigate
relationships between frequency of high intensity impacts, high intensity running
during each half of match-play. RESULTS: A significant negative correlation was
found for high intensity impacts sustained during the 1st half of match-play and
the frequency of 2nd half sprinting movements. Specifically zone 6 impacts (>
10G) experienced by players during the 1st half had a negative influence on 2nd
half total sprint (Zone 6) distance r = -0.42 (p < 0.05), the number of sprints
r = -0.31 (p < 0.05), average sprint distance r = -0.45 (p < 0.05), and average
velocity after rapid acceleration r = -0.38 (p < 0.05). No significant correlation
was found between frequency of 1st half heavy impact collisions and 2nd half
acceleration efforts. CONCLUSION: The present study provides insight into the
high intensity nature of elite Rugby competition incorporating accelerometer
and GPS technology to establish key performance indicators of match-play. The
results identify significant negative influence of repeated high intensity impacts
experienced by players during collisions associated with offense and defense
match-play characteristics on high intensity running and sprinting profiles during
the 2nd half of match-play. PRACTICAL APPLICATIONS: Repeated blunt force
trauma associated with high intensity match-play collisions are a fundamental
characteristics of elite Rugby match-play. Accordingly, the influence of repeated
high intensity collisions experienced by players during the 1st half of competition
are likely to influence the high intensity running profile of players during the later
stages of completion. Coaches and conditioning staff should therefore consider
the inclusion of simulated match-play and training activities that incorporate
repeated high intensity collisions to replicate aerobic and anaerobic energy
system demands and simulate the requirements of competition to improve player
preparedness and optimise on field performance.
Poster: 53
TEST-RETEST RELIABILITY OF A COMMERCIALLY DESIGNED DEVICE FOR
ASSESSING SWAY INDEX DURING THE MODIFIED CLINICAL TEST OF SENSORY
INTEGRATION AND BALANCE
T. B. Palmer1, M. J. Hawkey1, R. M. Thiele1, D. B. Smith1, E. C. Conchola1,
B. M. Adams1, K. Akehi1, B. J. Thompson1
1
Oklahoma State University
There has been a recent interest in the use of commercially designed devices for
assessing sway index (SI) during the modified clinical test of sensory integration
and balance (m-CTSIB). As a result, it may be of great importance to propose and
examine the reliability of SI using these devices in conjunction with the m-CTSIB,
so that future studies can determine the minimum sample sizes necessary for
observing real differences with adequate statistical power. PURPOSE: To determine
the test-retest reliability of a commercially designed device for assessing SI
during the m-CTSIB. METHODS: Seventeen NCAA Division I female soccer players
(mean±SD, age=19±1yr; mass=63±8kg; and height=163±5cm) participated in
this investigation. Participants visited the laboratory three times, separated by
2-5 days at approximately the same time of day (±2hr). During the first visit,
participants became familiar with testing procedures. During the second and third
visits, participants performed two m-CTSIB assessments, with the average of the
two assessments being used for data analyses. For each m-CTSIB assessment,
participants removed footwear and positioned their feet on the device platform in
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PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
a comfortable stance width. Foot position was recorded using coordinates on the
platform’s grid to ensure the same stance for each assessment. Participants placed
their hands on their hips and maintained a steady upright posture throughout
testing. Each m-CTSIB assessment consisted of four, 20-second stance conditions
differing in somatosensory and visual input (condition 1 – eyes open firm surface,
condition 2 – eyes closed firm surface, condition 3 – eyes open foam surface, and
condition 4 – eyes closed foam surface). SI represented the postural sway from the
center point of the participant’s stance and was calculated and displayed by the
commercial device for each condition. The intraclass correlation coefficient (ICC,
model 2,k), the standard error of measurement (SEM), and the minimal difference
(MD) needed to be considered real were calculated across the final two visits to
asses reliability for SI during each condition. Systematic variability in SI for each
condition was examined using separate one-way repeated measures ANOVAs.
RESULTS: The reliability statistics for SI during the m-CTSIB assessments are
displayed in this study. CONCLUSIONS: The ANOVA results indicated no systematic
variability in SI across visits (P>0.05). Relative consistency was moderate with ICC
values ranging between 0.54–0.79, and absolute consistency was low with SEM
values (expressed as a percentage of the mean) ranging between 11.1–20.1%. MD
values ranged between 0.240–0.671. PRACTICAL APPLICATIONS: These findings
demonstrate that these commercially designed devices may be reliable for
measuring SI during a m-CTSIB assessment.
Poster: 54
STRENGTH CAPACITY IS INDEPENDENTLY ASSOCIATED WITH LOWER
CARDIOMETABOLIC RISK IN ADOLESCENTS.
M. D. Peterson1, W. Salterelli2, P. S. Visich3, P. Gordon1
1
University of Michigan, 2Central Michigan University,
3
University of New England
PURPOSE: Emerging evidence has demonstrated a role for resistance training
and strength preservation in the protection against cardiometabolic disease in
adults. The purpose of this study was to determine the sex-specific independent
association between muscular strength and cardiometabolic risk in a large cohort
(n=1409) of 6th grade adolescents. METHODS: Principal component analysis (PCA)
was used to determine the pattern of risk clustering and to derive a continuous
aggregate score (MetScore) from the following standard cardiometabolic risk
components: waist circumference (WC), fasting glucose, blood pressure, plasma
triglycerides levels, and HDL-cholesterol. Sex-stratified risk and MetScore were
assessed using general linear models for association with age, body composition
(percent fat), cardiorespiratory fitness (CRF), and muscular strength capacity
(normalized for body mass). RESULTS: In both boys (n=663) and girls (n=746),
age, CRF, percent fat, and strength were all individually correlated with multiple
risk components, as well as the overall MetScore. However, in the adjusted model
it was normalized strength capacity that emerged as the best predictor of
MetScore for both boys (β = -4.53; p<0.0001) and girls (β = -3.593; p<0.0001).
WC was the strongest loading coefficient within the PCA-derived MetScore
outcome. CONCLUSION: These findings reveal that strength-to-body mass ratio
is independently associated with lower cardiometabolic risk in adolescent boys
and girls. Moreover, WC was associated with all cardiometabolic risk factors
and carried the strongest loading coefficient within the MetScore outcome.
PRACTICAL APPLICATION: Previous research has demonstrated the value of
strength training to improve cardiometabolic risk in adults. This current study is
one of the largest epidemiological investigations to reveal a robust association
between strength capacity in adolescents and an aggregated cardiometabolic
risk profile, even after adjusting for other well-known clinical predictors, i.e.,
body composition and cardiorespiratory fitness. This finding serves to bolster
the importance of early strength acquisition, as well as the simultaneous need
to identify optimal behavioral interventions to reduce risk for abdominal obesity.
ACKNOWLEDGEMENTS: Funding for this project was provided by Memorial
Healthcare Foundation, Owosso, MI.
Poster: 55
COMPETITION PERFORMANCE BASED ON LEVEL IN
COMPULSORY FEMALE GYMNASTS
A. R. Russell1, H. Williford1, G. Schaefer2, M. Esco1
1
Auburn University Montgomery, 2Auburn University at Montgomery
Female artistic gymnasts in the United States (levels 1 through 6) are considered
compulsory gymnasts. All gymnasts at the same compulsory level (LV) perform
the same predetermined routines. Because LV is based on ability, even though
skill difficulty increases with LV, it would be expected that all-around competition
scores (AA) would be similar for each LV. However, many in the gymnastics
community maintain that AA varies by LV, with level 6 gymnasts scoring lower
than gymnasts in other compulsory levels, though there is currently no scientific
research to support this anecdotal hypothesis. PURPOSE: The purpose of this
investigation was to determine the difference in AA between level 4, 5, and 6
compulsory female gymnasts. METHODS: Four-hundred and thirty eight level 4 to
6 gymnasts from four states who competed in their compulsory championships
were randomly selected for data analysis. The AA score for each gymnast was
obtained from www.mymeetscores.com, a public website that publishes meet
results from many USA Gymnastics sanctioned events. The AA scores were
examined across levels 4 to 6. RESULTS: Mean AA by level was as follows: level
4 (n = 243) 34.73 +/- 2.01; level 5 (n = 130) 34.75 +/- 1.55; and level 6 (n = 64)
34.78 +/- 1.35. There was no significant difference between the AA scores (p >
0.05). CONCLUSIONS: This investigation suggests that AA scores do not differ
among compulsory female gymnasts between levels 4, 5, and 6. PRACTICAL
APPLICATIONS: This study indicates that AA is not affected by LV. As LV is
determined by ability, drops in AA at a higher LV may be the result of improper
LV placement for ability. Practitioners should carefully evaluate their athletes to
insure appropriate LV placement.
Poster: 56
PERCEIVED BELIEFS OF SAFETY PROCEDURE DEVELOPMENT AMONG HIGH
SCHOOL ATHLETIC AND CONDITIONING COACHES
G. Schaefer1, M. Esco2, A. R. Russell2, B. Nickerson2
1
Auburn University at Montgomery, 2Auburn University Montgomery
Of the countless number of injuries occurring in high school athletic and
conditioning settings, many can be prevented with adequate safety protocol.
The safety culture within an organization, such as a high school sports program,
may influence the behavior of employees regarding safety and can contribute to
the incidence of injury within the program. PURPOSE: The purpose of this study
was to explore the perceived beliefs of safety procedure development among
athletic and conditioning coaches within high school sports programs. METHODS:
The Recreational Sports Safety Culture Questionnaire, which was a previously
developed web-based survey, was distributed to 1425 high school athletic and
condition coaches via e-mail. A total of 124 surveys were completed (response
rate 8.7%). Under the construct proactive safety priority, participants addressed
the statement “employees are seldom asked for input when safety procedures
are developed.” Of the 114 usable responses, 8.8% strongly agreed, 16.7% agreed,
16.7% somewhat agreed, 14.9% somewhat disagreed, 30.7% disagreed and 12.3%
strongly disagreed. Participants also addressed the statement “employees get
little recognition for new safety ideas.” Of the 115 usable responses to the question,
9.6% strongly agreed, 15.7% agreed, 13% somewhat agreed, 19.1% somewhat
disagreed, 35.7% disagreed and 7% strongly disagreed. CONCLUSIONS: This
study showed that athletic and conditioning coaches in high schools have varied
beliefs of safety procedure development. Over 38% of the coaches surveyed
feel that they get little recognition for new safety ideas. In addition, over 42%
of the coaches surveyed believe their input for new safety ideas is not solicited.
PRACTICAL APPLICATIONS: Administrators of high school sports programs
should be aware of the results of this study when developing safety protocol
for their athletic and conditioning programs. Athletic and conditioning coaches
should be respected as an integral part of establishing safety procedures. Their
knowledge of the dangers involved with physical activity is vital when generating
a culture of safety. Further study is needed to investigate why so many athletic
and conditioning coaches believe that they have little input or get little recognition
for safety procedure development or new safety ideas.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 57
COACHED AND PERIODIZED EXERCISE TRAINING YIELDS SUPERIOR
IMPROVEMENTS IN LEAN BODY MASS COMPARED WITH SELF-DIRECTED
TRAINING IN HEALTH CLUB MEMBERS
T. Storer1, B. Dolezal1, M. Berenc2, J. Timmons3, C. B. Cooper1
Division of Pulmonary Medicine/University of California Los Angeles, 2Equinox
Fitness Clubs, 3Division of Endocrinology, Diabetes & Hypertension/University
of California Los Angeles
1
BACKGROUND: A variety of exercise training methods are available for improving
health- and performance-related fitness. However, it has not been established
whether personal trainers (coaches) applying fitness club structured but
individualized exercise training to members yield superior results when compared
with equivalent amounts of self-directed training. PURPOSE: We tested the
hypothesis that subjects randomized to a fitness club personal coaching method
(COACHED) would accrue significantly greater lean body mass (LBM) than those
randomized to directing their own training (SELF). Additionally, we examined
whether COACHED subjects would exhibit significantly greater improvements in
other fitness domains and with adherence with the training regimen. METHODS:
Males, 30-44 years who were members of a single Southern California fitness club
and regularly exercised 5-7 days/month were randomized to COACHED (N=17) or
SELF (N=17) for 12-weeks of thrice weekly training. COACHED subjects exercised
under the direction of coaches who applied the club’s periodized training program;
SELF subjects were instructed to exercise 3 days/week on their own. All subjects
were informed that the primary objective of training was to increase LBM. Coaches
were club employees with BS or MS degrees in exercise science and personal
training certifications. The primary outcome variable, LBM, was assessed by dualenergy x-ray absorptiometry, (DXA, Hologic 4500A, Bedford, MA). Secondary
outcomes included leg press and chest press muscle strength by 1-RM, leg power
using a vertical jump test and electronic timing mat (Just Jump , Probotics,
Inc., Huntsville, AL), and aerobic capacity (VO2max) measured with a portable
metabolic measurement system (Oxycon Mobile, Care Fusion, Yorba Linda, CA).
All measurements were conducted before and after 12-weeks of training. Other
than DXA, all assessments were performed by one investigator (BD) in the health
club setting; DXA scanning was administered by one of the investigators (JT) at
the UCLA Gonda (Goldschmied) Diabetes Center. Both investigators were blinded
to group assignment. RESULTS: COACHED subjects increased LBM by 1.3 (1.5) kg,
mean (SD), while SELF subjects showed 0.0 (1.6) kg increase (P=0.029 for the
difference between groups). Similarly, significantly greater improvements in chest
press muscle strength (42% versus 19%), peak leg power (6% versus 0.6%), and
VO2max (7% versus -0.3%) were seen in COACHED compared with SELF. Leg press
strength improved 38% and 25% in COACHED and SELF, respectively (P=0.14).
CONCLUSIONS: We conclude that significantly greater increases can be accrued
in LBM and other measures of fitness when fitness club members are coached by
well-trained, certified, and experienced coaches applying a systematic, periodized
training program over 12 weeks. PRACTICAL APPLICATIONS: While the results of
this study may seem predictable, it demonstrates for the first time in the real-world
environment of a health and fitness club setting, that significant improvements in
LBM and other important dimensions of health and performance-related fitness
are best achieved when periodized exercise training is administered by expert
coaches. These data, therefore, lend credence to the personal training profession
wherein knowledgeable coaches using proven training methods yield superior
results when compared with individuals who self-train with similar objectives.
ACKNOWLEDGEMENTS: Funding: Equinox Fitness Clubs, New York, NY.
Poster: 58
ANTROPOMETRIC VARIABLES, AEROBIC FITNESS AND REACTION TIME IN
CLUB LEVEL RUGBY PLAYERS AND TRAINED MALES
C. Tai1, P. Falcone1, L. Carson1, B. Spradley2, K. Crowley2, A. Magner2,
E. Esposito3, M. Kim1, E. Serrano1, J. Moon1
1
MusclePharm Sports Science Center Research Institute,
2
United States Sports Academy, 3University of Mobile
Rugby is played in more than 100 countries, and professional rugby leagues exist
all over the world. There are fifteen rugby player positions and they each require
different skills and physiological demands. However, reaction time differences
among these position-specific athletes, as well as differences in anthropometric
and aerobic characteristics, are unclear. PURPOSE: To compare physiological
ability, including reaction time, VO2max, and muscular strength among different
positions in college level rugby players as well as to compare rugby athletes to
recreationally trained men. METHODS: Thirty-six active males ages 18-35 years,
including 19 rugby team players (8 rugby forwards and 11 rugby backs) and 17
trained males participated in this study. Body composition and anthropometry
measurements included: height, weight, body fat, and lean muscle mass. Aerobic
capacity tests were performed on a calibrated treadmill and data were measured
via a metabolic cart. Choice reaction time was measured with an audio-visual
reaction time testing device. RESULTS: Weight and percent fat were significantly
(p<0.05) higher for rugby forwards (102.14 ± 13.63kg; 26.06 ± 8.65 %) compared
to rugby backs (76.67 ± 11.94kg; 13.45 ± 5.05%) and trained males (80.58 ±
13.39kg; 17.42 ± 5.69%). Absolute VO2max was also significantly (p<0.05) higher in
rugby forwards (4.36 ± 0.62 l/min) compared to rugby backs (3.63 ± 0.45 l/min)
and trained males (3.69 ± 0.52 l/min). Rugby players had significantly (p<0.05)
faster reaction times (0.28 ± 0.02 to 1.07 ± 0.09 sec) compared to trained males
(0.31 ± 0.03 to 1.10 ± 0.09 sec). CONCLUSIONS: Higher body fat, body mass and
absolute aerobic capacity appear to benefit club level rugby forwards. Club level
rugby players demonstrated faster reaction times compared to trained males.
PRACTICAL APPLICATIONS: Rugby players appear to have faster reaction time
than trained men. Participating in club level rugby may enhance both aerobic
performance and reaction time over typical recreational activities. Furthermore,
rugby clubs can use this data to recruit athletes based on size and aerobic
performance as well as reaction time. ACKNOWLEDGEMENTS: This investigation
was supported by a grant from MusclePharm, Inc.
Poster: 59
A COMPARISON OF PERCEPTUAL AND PHYSIOLOGICAL TRAINING LOADS
DURING BASKETBALL-SPECIFIC CONDITIONING RELATIVE TO TRAINING MODE
P. Tucker1, A. Scanlan1, V. Dalbo1
1
Central Queensland University
*Award Eligible - Outstanding Doctoral Student Poster Presentation
PURPOSE: The monitoring of individualized athlete responses to training stimuli
is important to coaches and conditioning staff in team sports. Perceptual (ratings
of perceived exertion (RPE)) and physiological (heart rate) models have emerged
as the most commonly used methods to quantify training load in team sports.
To date, limited investigation has explored the use of these training load models
during basketball-specific conditioning. Furthermore, no research has examined
the relationship between perceptual and physiological training load across
different modes of basketball conditioning. Therefore, the purpose of this study
was to compare perceptual training load responses with physiological methods
across a variety of training modes in basketball players. METHODS: Eight adult
semi-professional male basketball players (age: 26.3 ± 6.7 years; stature: 188.1 ±
6.2 cm; body mass: 92.0 ± 13.8 kg) participated in the study. All players were
monitored across general and specific preparatory phases of an annual training
plan. The training modes analysed included off-court, repeated linear running and
sprinting efforts (43 sampled sessions); on-court intermittent work combined
with speed and agility drills (46 sampled sessions); and tactical/game-play
conditioning (37 sampled sessions). Following (~30 min) each training session,
players reported their perceived intensity (Borg CR-10 scale) of the overall session,
which was used to calculate perceptual training load (RPE x training duration
(min)). In addition, heart rate responses were recorded across sessions and used
to calculate individual physiological training load via Bannister’s training impulse
(TRIMP) and Edwards’ summated-heart rate zones models (ZONE). Correlation
analysis was used to compare the perceptual and physiological training load
methods during the different training modes. RESULTS: The mean perceptual and
physiological training loads (arbitrary units) varied between the linear (RPE: 254
± 74; TRIMP: 62 ± 21; ZONE: 123 ± 31), intermittent (RPE: 360 ± 63; TRIMP: 62 ± 19;
ZONE: 121 ± 32) and tactical/game-play training modes (RPE: 670 ± 177; TRIMP: 121
± 32; ZONE: 288 ± 58). Significant (p<0.05) correlations were observed between
perceptual and physiological training load models for each training type. The
strongest correlations were apparent during the linear drills (RPE-TRIMP: r = 0.53;
RPE-ZONE: r = 0.75) and tactical/game-play conditioning (RPE-TRIMP: r = 0.60;
RPE-ZONE: r = 0.63). Weaker correlations were evident during the intermittent
on-court drills (RPE-TRIMP: r = 0.38; RPE-ZONE: r = 0.52). CONCLUSIONS: The
present data support the agreement between RPE and heart rate methods to
quantify training load during various modes of basketball conditioning. Notably,
weaker correlations were observed between perceptual and physiological
measures during on-court intermittent conditioning. This finding may be due
to an increased perceptual demand relative to cardiovascular responses during
the multi-directional, intermittent-focused drills performed during this training
mode. PRACTICAL APPLICATIONS: The use of either perceptual or physiological
training load models by coaches and conditioning staff can be effectively used
to monitor individual training demands in basketball team environments. If
properly utilized, these practices may permit the development of more precise
periodized conditioning plans as well as the prevention of overtraining syndrome
in basketball players.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 60
EFFECTS OF THREE RECOVERY PROTOCOLS ON BASEBALL PITCHERS DURING
SIMULATED GAMES
C. Warren1, D. Szymanski2, M. Landers 3
1
Center for Athletic Performance and Physical Therapy,
2
Louisiana Tech University, 3University of Las Vegas
Baseball pitching has been described as an anaerobic activity from a bioenergetics
standpoint with short bouts of recovery. Depending on the physical conditioning
and muscle fiber composition of the pitcher as well as the number of pitches
thrown per inning and per game, there is the possibility of pitchers fatiguing during
a game, which could lead to a decrease in pitching performance. PURPOSE: To
evaluate the effects of 3 recovery protocols: passive recovery (PR), active recovery
(AR), and electrical muscle stimulation (EMS) on range of motion (ROM), heart
rate (HR), rating of perceived exertion (RPE), and blood lactate in baseball pitchers
after throwing a simulated game. METHODS: Twenty One Division I intercollegiate
baseball pitchers (age = 20.4 ± 1.4 yr, ht = 185.9 ± 8.4 cm, wt = 86.5 ± 8.9 kg, %BF
= 11.2 ± 2.6) volunteered to pitch 3 simulated 5-inning games, with a maximum of
70 fastballs thrown per game while wearing a HR monitor. ROM was measured
pre, post, and 24 hr post-pitching for shoulder internal and external rotation at
90º and elbow flexion and extension. HR was recorded after each pitch and after
every 30 sec of the 6-minute treatment recovery. RPE was recorded after the
last pitch of each inning and after completing each 6-minute treatment recovery.
Immediately after throwing the last pitch of each inning, post-pitching blood
lactate was measured. At the end of the 6-minute treatment recovery, before
the next inning started, post-recovery blood lactate was measured. Pitchers were
instructed to throw each pitch at or above 95% of their best pitched fastball.
This was enforced to ensure that each pitcher was throwing close to maximal
effort for all 3 simulated games. All data presented represent group means.
RESULTS: Repeated measures ANOVA indicated that the method of recovery did
not significantly influence ROM (p > 0.05); however, it did significantly influence
blood lactate levels (p < 0.01), HR, and RPE. Blood lactate levels significantly
decreased from post-pitching to post-recovery in the EMS recovery condition,
but did not change for either the active or the passive recovery conditions. RPE
decreased from the post-pitching to post-recovery in both the passive and EMS
recovery methods, but did not for active recovery. HR decreased for all conditions
from post-pitching to post-recovery. CONCLUSIONS: The use of EMS was the
most effective method at reducing blood lactate after 6 min of recovery during
a simulated game (controlled setting). PRACTICAL APPLICATIONS: Although
EMS significantly reduced blood lactate levels post-recovery, blood lactate levels
post-pitching in the simulated games were never high enough to cause skeletal
muscle fatigue and decrease pitching velocity. If a pitcher were to throw more
than 14 pitches per inning, throw more total pitches than normal per game, and
have blood lactate levels increase higher than in the simulated games in this study,
the EMS recovery protocol may be beneficial to pitching performance by aiding
recovery. This could potentially reduce some injuries associated with skeletal
muscle fatigue during pitching, may allow a pitcher throw more pitches per game,
and may reduce the number of days between pitching appearances.
Poster: 61
EFFECT OF DIFFERENT NUMBER OF SETS (TRAINING VOLUME) ON RANGE OF
MOTION IN THE SHOULDER JOINT
E. Bezerra1, î Queiroz2, G. A. Paz3, M. D. Maia3, H. Miranda3, R. Simão3
Federal University of Amazonas, School of Physical Education, Manaus, AM.,
2
Graduate Program at the University Traz-os-Montes e Alto Doro – UTAD,
Portugal, 3Federal University of Rio de Janeiro, School of Physical Education
and Sports, Rio de Janeiro, RJ
1
PURPOSE: To investigate the effect of the number of sets (training volume)
on shoulder joint flexibility in untrained males. METHODS: Sixty-one healthy
untrained males (23±2years, 81.64±11.97 kg; 1.7±0.06m) were random divided into
three groups: two sets (G2, n = 18), three sets (G3, n = 19) and control group (CG, n
= 24). The baseline evaluation was carried out through anamnesis and goniometry
analyses of shoulder joint. Following this procedure, the subjects underwent two
weeks of familiarization in bench press (BP) and lat pull down (LPD) resistance
exercises. During familiarization period, three sessions per week were performed
through two sets of 10-12 repetitions with sub maximal loads adopting 2-minute
rest interval between sets and exercises. After the familiarization period, the 10
repetition maximum (RM) test and retest was applied for BP and LPD (72h apart).
The shoulder flexibility was assessed immediately after the resistance training
session (P0), 24h (P24) and 48h (P48) post-workout. The shoulder movements
evaluated were flexion, extension, abduction and horizontal adduction. During RT
sessions, the G2 and G3 performed repetition maximum to failure in BP followed
by LPD with 10RM loads using 90s rest interval between sets and exercises.The CG
did not performer any exercise during the testing period. A one-way ANOVA with
Tukey post hoc test was applied to verify differences intra-groups (baseline, P0,
24h and 48h). To analyze the differences inter-groups the Scheffé pos hoc test was
adopted (p<0.05). The current study was carried out following the Declaration
of Helsinki and the US Department of Health and Human Services Policy for the
Protection of Human Research Subjects (US Code, Title 45, Part 46 Protection
of Human Subjects). RESULTS: The G2 group showed a significant difference in
shoulder flexion flexibility among baseline (168.03 ± 6.84), P24 (172.82 ± 4.47)
and P48 (173.89 ± 6.79). The shoulder flexion flexibility showed a significant
difference in G3 among P24 (165.24 ± 7.59) and P48 (173.65 ± 5.36). In the
intergroup analyses no significant differences were observed in the four periods
evaluated. CONCLUSIONS: These results indicating that the shoulder flexibility
was only affected in flexion movement independent of the number of the sets
performed. Probably the biomechanical characteristics of the flexion movement
induce changes on muscle proprioceptors responses, as well as muscle spindles
and golgi tendon organs. PRACTICAL APPLICATIONS: The variability in the
number sets (training volume) may be an interesting alternative for coaches and
practitioners to improving the shoulder flexibility in an acute manner, especially
during movements involving shoulders.
Poster: 62
THE EFFECT OF A SIX-WEEK STRENGTH & CONDITIONING PROGRAM ON
DANCE SPECIFIC MEASURES OF FLEXIBILITY AS WELL
AS SELF-PERCEIVED ABILITIES
R. Kudrna1, J. Martin1, K. Rose1
1
DeSales University
Previous research has shown that strength training and metabolic conditioning
in dancers can improve strength and reduce fatigue while dancing. Yet many
traditionally trained female dancers fear a loss of flexibility or visual aesthetics and
therefore avoid most types of strength and conditioning. There is minimal research
examining the benefits and detriments of traditional strength and conditioning
methods on the unique physical demands of dancers such as hip external rotation,
posture, and dance specific flexibility. PURPOSE: The purpose of this study was to
examine the effects of a 6-week non-specific strength and conditioning program
on dance specific active and passive flexibility. Secondly, this study examines
changes in perceived somatic abilities and confidence over the same period of
time. METHODS: Fifteen female collegiate dance majors (19.4±1.68yrs of age,
59.3±9.4kg, 12.8±3.8hrs of class and rehearsal per week) were divided into control
(CON; n=6) and experimental (EXP; n=9) groups. The EXP group participated in
a 6-week strength and conditioning program two times per week for 1 hour in
addition to their usual dance classes, rehearsals, and personal practice. The CON
group continued with their normal dance and fitness activities only. Functional
hip external rotation, height of active and passive developé in second position,
and posture in first position, were measured in both groups before and after the
6-week intervention. A questionnaire assessing 5 self-perceived dance specific
somatic abilities as well as confidence was also administered at the beginning
and end of the study. RESULTS: Separate mixed model ANOVAs were performed
for hip external rotation, active and passive developé height, posture, and items
of the self-perception questionnaire. There were no differences in functional hip
external rotation or active and passive developé height between EXP and CON
(group), from pre to post testing (time), nor were there significant interactions
(time*group). Among the items of the self-perception questionnaire, perceived
strength in dancing (F(1,13)= 10.023, p=0.007) and dance specific confidence
(F(1,13)= 4.743, p=0.048) significantly increased over the 6-week period, but
no main effect for group or interaction (time*group) was observed. There was
a significant interaction effect for perceived ability to achieve and hold dance
specific posture (time*group; F(1,13)= 9.274, p=0.009), but no main effects for
time or group. The postural assessment of first position showed no differences
between groups (EXP vs. CON), time points (pre vs. post), or the interaction
(time*group). CONCLUSION: Strength and conditioning training in dancers did
not affect hip external rotation or developé height. The EXP group perceived
greater ease in achieving and maintaining proper posture in dance following
the training intervention, but actual postural assessment did not change. In all
other variables the EXP group responded similarly to the CON group. Further
research is needed to examine if long-term conditioning in this manner produces
any additional changes in flexibility, posture, or other dance specific abilities.
PRACTICAL APPLICATION: It appears that short-term strength & conditioning
concurrent with dance specific training does not affect active or passive dance
specific flexibility but may increase the perceived ease of dance posture.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 63
ASSISTIVE DEVICE PROVIDES COMPARABLE INCREASES IN
HAMSTRING FLEXIBILITY AND STRENGTH IN ELITE TRACK & FIELD
ATHLETES COMPARED TO A TRAINED THERAPIST
C. Sutherland1, A. Kanters1, D. Andrews1
1
University of Windsor
PURPOSE: Track and field athletes who exhibit a lack of muscle and tendon
flexibility are at a higher risk of sustaining a hamstring injury, compared to
those athletes with normal flexibility. In order to minimize the athlete’s risk of
injury and maximize their performance, all athletes should be implementing a
structured stretching regime into their everyday training program. Proprioceptive
Neuromuscular Facilitation (PNF) stretching post training is preferred among
university track and field athletes because it has been shown to yield greater
increases in strength and range of motion compared to static and dynamic
stretching. However, conducting PNF stretching on each individual member of a
large varsity team following daily training sessions is not always feasible for a team’s
therapist due to time constraints and limited resources. Therefore, the purpose of
this research study was to determine if athletes who use an assistive device to
facilitate PNF stretching will have comparable increases in hamstring flexibility
and strength as athletes who receive PNF stretching from the team’s therapist.
METHODS: Thirty-three university track and field athletes (runners, jumpers and
throwers: mean age=22.2 yr, mass=71 kg, height=175 cm) participated in this study
and were purposely assigned to one of three groups: 1) PNF; PNF stretching was
performed after each practice by the team’s therapist (n=9), 2) Assistive Device;
PNF stretching was performed after each practice by the participant using a
newly developed assistive device (n=14), 3) Control; did not perform any PNF
stretching (n=10). Four repetitions of the contract-relax PNF stretching technique
was used for both the PNF and Assistive Device group, 5 times a week for 10
weeks. Three tests were performed pre, mid and post intervention: 1) sit and reach
test for flexibility, 2) active knee extension test for muscle tightness, 3) isokinetic
leg curls for strength. A 3 (Group: PNF, Device, Control) x 3 (Time: Pre, Mid, Post)
repeated measures ANOVA was performed for flexibility. A 3 (Group) x 3 (Time)
x 2 (Leg: Right, Left) repeated measures ANOVA was performed for the active
knee extension test and the isokinetic leg curls. RESULTS: A significant main effect
for time (p<0.05) was found for flexibility, muscle tightness, and concentric and
eccentric strength across all 3 groups. All measures improved significantly at mid
and post testing compared to pre. A significant main effect for leg (p<0.05) was
found for muscle tightness, and concentric and eccentric strength. The right leg
showed a lower degree of flexion and was able to generate more force for both
the concentric and eccentric leg curls, compared to the left leg. CONCLUSIONS:
The assistive device was able to help athletes achieve equivalent improvements
in their hamstring flexibility, tightness and strength compared to the PNF group.
Although all participants increased in hamstring flexibility, tightness and strength
over the duration of the study, there were greater increases in the PNF and Assistive
Device groups compared to the Control group. PRACTICAL APPLICATIONS: The
assistive device used in this study will enable athletes to gain the benefits of
PNF stretching within their personal training sessions without the need to rely
on support staff. ACKNOWLEDGEMENTS: Green Shield Sports Therapy Clinic
(Dave Stoute and Kathy Harvie), Manufacturing Solutions Ltd. (Paul Mancini), the
Downtown Windsor Business Accelerator (Deborah Livneh) and MITACS provided
support for this study.
Poster: 64
EFFECT OF SODIUM-SODIUM CITRATE BEVERAGE SUPPLEMENTATION ON
SKIN TEMPERATURE & SWEAT RATE IN PREVIOUSLY HYPOHYDRATED SOCCER
ATHLETES IN A HOT ENVIRONMENT
K. A. Brooks1, J. G. Carter2, J. Dawes1
1
Texas A&M University Corpus Christi, 2Texas A&M University
INTRODUCTION: Research has shown that many athletes are continually in a
state of dehydration. This impairs performance, and increases the chance of heatrelated illness. Using sodium supplementation to increase fluid absorption and
stimulate the thirst mechanism has proven effective in rehydration. PURPOSE: The
purpose of this study was to determine if ingesting a beverage containing 1,780
mg of sodium and 2,953 mg of sodium citrate would impact skin temperature and
sweat rate for previously hypohydrated individuals in a heated environment during
aerobic exercise. METHODS: Five division one female soccer athletes participated
in the study. The subjects had the following descriptive statistics: Age 19 ± 0.7 yr,
Height 162.3 ± 4.6 cm, Weight 63.2 ± 8.1 kg, %BF 23.68 ± 9.2%, and VO2max 60.2 ± 5.1
ml∙kg-1∙min-1. The study required subjects (N=5) to run the experimental protocol
twice. Fluid intake was matched for each condition. Prior to running to exhaustion
at 70% of their VO2max on a treadmill in a heated chamber, the subjects were
passively dehydrated and loss 2.5% of their body mass. The subjects were given 2
hours to rehydrate via either a placebo (10 mmol Na+∙L-1) or the supplement (164
mmol Na+∙L-1). After medical clearance, subjects performed a graded exercise test
to determine VO2max. ACSM equations were used to determine running speed at
70% of VO2max. Testing conditions consisted of the subjects running at 70% of their
VO2max until exhaustion while in a heated chamber at 90° Fahrenheit. The study
employed a double-blind, repeated measure, within subject protocol. The treadmill
protocol consisted of a five minute warm-up (3 minutes at 40% of their VO2max and
2 minutes at 55% of their VO2max), running to exhaustion at 70% of VO2max, and
a 10 minute cool down at 3.0 mph. Every five-minute period on the treadmill,
variables were assessed. RESULTS: Results for skin temperature and sweat rate at
70% of maximal VO2 indicated that there were no significant differences between
conditions for sweat rate. One participant doubled sweat rate during the TRS
trial, although no significance was observed overall. There were no significant
differences between conditions for skin temperature until the 25 minute mark.
At the 25, 30, 35, and 40 minute marks, there was a significant difference in skin
temperature (p<0.05), with the supplement trial reporting lower skin temperatures
at each mark. CONCLUSION: Skin temperature was lower when hydrated with
the sodium supplemented beverage after sustained aerobic exercise at 70% of
VO2max, in a hot environment. The ability to maintain a lower body temperature
may lead to increased performance through maintenance of blood volume and
a decreased effect of cardiovascular drift. Notably, all of the subjects performed
better on the first treadmill session regardless of the experimental condition (i.e.
placebo or high sodium solution). Absolute conclusions cannot be drawn from
this study. PRACTICAL APPLICATION: Dehydration should be a major concern for
any athlete, especially for those who are performing in hot, humid environments.
Preventative methods such as ingesting a sodium solution, frequent weigh-ins,
and continual education for the athlete should all be employed to avoid any form
of heat illness to the athlete. Practitioners should be aware of the importance
of aerobic conditioning for an athlete while exercising in a hot environment.
Knowledge of warning signs and symptoms, and taking proper precautions to
prevent complications is of importance. Coaches should be aware that athletes
who are less conditioned are at higher risk for heat illnesses; therefore, proper
training and steps towards acclimatization must be employed prior to training in
the heat.
Poster: 65
EFFECTS OF ANATABINE ON MARKERS OF ECCENTRIC-INDUCED MUSCLE
DAMAGE AND DELAYED-ONSET MUSCLE SORENESS
N. D. Jenkins1, D. A. Traylor1, T. J. Housh1, K. C. Cochrane1, H. C. Bergstrom1,
R. W. Lewis, Jr1, R. J. Schmidt1, G. O. Johnson1, J. T. Cramer1
1
University of Nebraska-Lincoln
INTRODUCTION: Anatabine is a minor tobacco alkaloid found in Solanaceous
plants (e.g., green tomatoes, peppers, and eggplant) and is sold as a dietary
supplement for reducing the urge to smoke. Paris et al. (Eur J Pharmacol, 698[13]:145-153, 2013) suggested that anatabine may also exhibit anti-inflammatory
activity, however, the effects of anatabine on markers of exercise-induced muscle
damage and delayed-onset muscle soreness (DOMS) are unknown. PURPOSE:
To examine the effects of anatabine on selected markers of muscle damage and
DOMS after eccentric exercise. METHODS: Using a double-blinded, placebocontrolled, crossover design, 16 men (mean ± SD age = 22 ± 3 years; body mass =
79 ± 16 kg; height = 182 ± 6 cm) participated in two randomly-ordered conditions
separated by at least a two-week washout. The anatabine condition consisted of
consuming 1-4 lozenges per day for 10 days, and testing took place during days
7-10. The placebo condition was identical except that the lozenges contained
no anatabine. Maximal voluntary isometric contraction peak torque (PT) of the
forearm flexors, arm circumference, hanging arm elbow joint angle, subjective
pain ratings, and serum concentrations of creatine kinase (CK, IU∙L-1), myoglobin
(Mb, ng∙mL-1), lactate dehydrogenase (LDH, IU∙L-1), and high sensitivity C-reactive
protein (CRP, mg∙L-1) were measured before (Test 1), immediately after (Test 2),
and 24 (Test 3), 48 (Test 4), and 72 (Test 5) hours after six sets of ten maximal,
eccentric isokinetic forearm flexion muscle actions at 30˚∙s-1. Eight separate twoway repeated measures ANOVAs (condition [anatabine vs. placebo] x time [Test
1 vs. 2 vs. 3 vs. 4 vs. 5]) with planned pairwise comparisons dependent samples
t-tests (anatabine vs. placebo) were used to analyze the results with an alpha
level of p ≤ 0.05. RESULTS: There were no condition x time (p > 0.05) interactions,
there was only one main effect for condition for LDH (anatabine > placebo, p ≤
0.05), and there were main effects for time (p ≤ 0.05) for all variables (PT, arm
circumference, hanging arm elbow joint angle, subjective pain ratings, CK, Mb,
LDH, and CRP). For example, PT decreased from Test 1 to Test 2 (70 ± 14 to 41 ± 14
Nm and 72 ± 15 to 40 ± 12 Nm) and then recovered to 77% and 71% of Test 1 by 72
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
hours after exercise similarly for anatabine and placebo conditions, respectively.
CK increased from Test 1 to Test 5 (219 ± 395 to 6,021 ± 9,204 IU∙L-1 and 135 ± 184 to
3,806 ± 5,243 IU∙L-1) similarly for anatabine and placebo conditions, respectively.
LDH increased from Test 1 to Test 5 (131 ± 28 to 218 ± 170 IU∙L-1 and 112 ± 24 to 154
± 71 IU∙L-1) for anatabine and placebo, respectively, but was consistently higher (p
≤ 0.05) during the anatabine condition. CONCLUSIONS: Despite the characteristic
decreases in PT and increases in CK that were consistent with previous studies on
muscle damage, these data were unable to support the hypothesis that anatabine
improves recovery after this model of eccentric-induced muscle damage and
soreness. PRACTICAL APPLICATIONS: While anatabine may be of value as a
dietary supplement to reduce the urge to smoke or for other muscle or joint
conditions, it did not prove of value for PT, arm circumference, elbow joint angle,
pain scale ratings, CK, Mb, LDH, or CRP during a 3-day period following this model
of eccentric-induced muscle damage and DOMS. ACKNOWLEDGEMENTS: This
study was supported by a clinical trial grant from Rock Creek Pharmaceuticals.
Poster: 66
PRACTICAL BLOOD FLOW RESTRICTION TRAINING INCREASES MUSCLE
HYPERTROPHY DURING A PERIODIZED RESISTANCE TRAINING PROGRAM
R. P. Lowery1, J. M. Joy1, J. P. Loenneke2, E. Oliveira de Souza3, M. A. Naimo1,
M. Machado4, J. E. Dudeck1, S. I. Weiner1, S. A. McCleary1, J. M. Wilson1
University of Tampa Human Performance Lab, 2University of Oklahoma /
Neuromuscular Laboratory, Norman, OK, 3Laboratory of Neuromuscular
Adaptations to Strength Training, School of Physical Education and Sport,
University of São Paulo, 4Laboratory of Human Movement Studies,
University Foundation of Itaperuna, Itaperuna, RJ, Brazil
1
*Award Eligible - Outstanding Undergraduate Student Poster Presentation
Resistance training in combination with practical blood flow restriction (pBFR)
is thought to stimulate muscle hypertrophy by increasing muscle activation and
muscle swelling. Most previous studies used the KAATSU device; however, little
long-term research has been completed using pBFR. OBJECTIVE: To investigate
the effects of pBFR on muscle hypertrophy. METHODS: Twenty-four college-aged
male participants with a minimum of 1 year of resistance training experience were
recruited for this study. Our study consisted of a randomized, crossover protocol
consisting of individuals either using pBFR for the elbow flexors during the first 4
weeks (BFR-HI) or the second 4 weeks (HI-BFR) of an 8-week resistance-training
program. Direct ultrasound determined biceps muscle thickness was assessed
collectively at baseline and at the end of weeks 4 and 8. A repeated measures
ANOVA was used to assess any main effects. If a main effect was found a tukey post
hoc was employed to locate where differences occurred. RESULTS: There were no
differences in muscle thickness between groups at baseline (p=.52). There were
time (p<0.01, ES=.99) but no condition by time effects (p=0.58, ES=.80) for muscle
thickness in which the combined values of both groups increased on average from
Week 0 (3.66±.06) to Week 4 (3.95±.05) to Week 8 (4.11±.07). However, both the
BFR-HI and HI-BFR increased significantly from baseline to Week 4 (6.9% and
8.6%, p<0.01) and from Weeks 4 to Week 8 (4.1%, 4.0%, p<0.01), respectively.
CONCLUSION: The results of this study suggest that pBFR can stimulate muscle
hypertrophy to the same degree to that of high intensity resistance training.
PRACTICAL APPLICATIONS: Athletes and strength practitioners can use LI-pBFR
in combination with their training programs in order to elicit muscle hypertrophy
without the muscle damage incurred by heavier weight.
Poster: 67
NORMATIVE TRAINING VOLUME AND SLEEP HABITS OF RECREATIONAL
ATHLETE WHO SUCCESSFULLY COMPLETED A 160 KM CYCLING EVENT
J. R. Hydren1, E. C. Johnson1, J. Baker1, L. E. Armstrong1
1
University of Connecticut Department of Kinesiology,
Human Performance Laboratory
The high level of participation in ultra endurance events by recreational athletes
may require large training volumes. Finding the optimal training volume requires
sufficient training to cause physiological adaption without overtraining, which
leads to decrements in performance or injury. PURPOSE: To define normal training
volume and sleep habits for successful completion of a 160 km cycling event in
recreationally active individuals and to determine if training volume effected finish
time. METHODS: Fifty three subjects (men, 47; women, 6; age, 43.6±8.7 yr; height,
179.5±7.1 cm; weight 85.4±13.7 kg; body fat: men, 16±5.0%, women, 24.2±2.5%)
completed a survey before a 160 km (100 mi) endurance cycling event in Witchita
Falls, Texas in August of 2011. Information included: hours and rides per week,
rating of perceived exertion (RPE, 6-20 point scale) for a typical training ride for
the previous three months (0-4WK, 5-8WK, 9-12WK); how many months since
they experienced a three week break from training; and the hours and quality
(poor, 1; good, 5) of sleep on a typical weekday (Wkd) and weekend (Wkend)
night. An investigator recorded body mass and three-site skinfold thickness 4812 hours before the event. The organizer of the event provided finish times and
subjects reported RPE at the finish. Subjects were retrospectively assigned to one
of three groups (FAST, MED, SLOW) by an analysis of ride time and finish rank
order. RESULTS: See table. During the event temperature rose from 25.6° to 41.1°
C with humidity of 31.8±15.8% and calm winds (<7.4 kph). MED trained more hours
per week than FAST but at a lower RPE for the month leading up to the event
(p<0.05). Finish RPE correlated with finish time, but not with measure of training
volume. Longer nights of sleep occurred on the weekends (Wkd, 6.7±1.0; Wkend,
7.3±0.9 hr, p<0.001) with similar quality(Wkd, 3.7±0.8; Wkend, 3.8±0.7, p=0.057).
Weekday-sleep-length weakly correlated with finish time (r= -0.284, p<0.05).
Subjects reported 4.8±8.0 years since the last 3+ week break in physical activity,
and 96% of subjects reported training three month consecutively prior to the
event. CONCLUSION: Exercise training intensity was higher in the fast group and
weekday-sleep-length explained a small portion of the variance in finish times.
PRACTICAL APPLICATION: This survey research provided relatively stable normal
training volumes across a wide range of abilities. Normal cyclist habits for a 160
km (100 mi) endurance cycling event were in the range (95% confidence interval)
of 3-4 rides for a total of 8.1-11.5 hours per week, at an RPE of 13.5-14.8 for three
months prior to the event, with 6.5-7.0 hours of sleep per night. Therefore, general
guidelines for training goals for those seeking to complete a 100 mile ride should
be to cycle at least 3 times a week for a total of at least 8 hours per week, at an
intensity subjectively judged to be between “somewhat hard” and “hard.”
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Saturday, July 13, 2013, 8:30 AM - 8:45 AM
EFFECT OF LADDER CLIMBING ON REGIONAL ANTERIOR PITUITARY
IMMUNOREACTIVE GROWTH HORMONE RELEASE IN MALE RATS
W. J. Kraemer1, S. Flanagan1, C. Dunn-Lewis1, B. Comstock1, D. Hooper1,
T. Szivak1, A. Sterczala1, D. Looney1, A. Bryce1, H. Luk1
1
University of Connecticut
PURPOSE: Anterior pituitary gland (AP) somatotroph growth hormone (GH)
release is increased in response to resistance exercise. The purpose of this
study was to examine the effects of resistance exercise on regional AP in vitro
GH release in male rats. METHODS: Twelve-month old Sprague-Dawley rats
were randomly assigned to one of four groups: 1) No training and no acute
exercise (NT-REST), 2) No training and acute exercise (NT-EX), 3) Training and
no acute exercise (RT-REST), and 4) Training and acute exercise (RT-EX). The
resistance exercise incorporated ten 1-meter long weighted ladder climbs at an
85° angle. RT groups trained three days per week for seven weeks. After rats were
euthanized, the AP was removed and divided into four regions (ventral-dorsal
and left-right). For each region, unstimulated immunoreactive GH release, % of
cells containing GH, forward angle light scatter (FALS) measures of cell size, and
perpendicular light scatter (PLS) measures of cell cytoplasmic granularity were
taken. RESULTS: GH release was significantly (p<0.05) higher in RT-EX compared
to RT-REST and NT-REST in ventral regions and compared to NT-REST in the
left dorsal region. FALS was significantly lower (p<0.05) in RT-EX compared to
NT-EX in the left ventral region. PLS was significantly (p<0.05) lower in RT-EX
compared to RT-REST and in NT-REST compared to RT-REST in the right ventral
region. Plasma GH trunk blood concentrations were: (NT-REST) 8.9±2.4 µg●L-1;
(NT-EX) 15.6±3.4 µg●L-1; (RT-REST) 9.2±3.5 µg●L-1; and (RT-EX) 23.4±4.6 µg●L-1.
There were no significant differences between resting values. Acute resistance
exercise (NT-EX) was accompanied by significantly higher plasma GH than both
resting conditions. Finally, training (RT-EX) resulted in significantly higher GH
concentrations than acute resistance exercise alone (NT-EX). CONCLUSIONS:
Resistance exercise training appears result in greater unstimulated GH release,
smaller somatotroph size, and increased granular content at rest. In addition, the
amount of immunoreactive GH secreted in response to training increases. These
adaptations are not homogeneous but region specific in nature. PRACTICAL
APPLICATIONS: Understanding the basic underlying mechanisms for GH release
from the pituitary provides new insights in to the 22 kD release from the pituitary
using a model not possible in humans. Saturday, July 13, 2013, 8:45 AM - 9:00 AM
THE RELIABILITY OF ISOMETRIC FORCE-TIME VARIABLES COLLECTED ON A
PORTABLE MID-THIGH PULL TESTING DEVICE
G. Haff1, S. Nimphius2, J. Sheppard3
1
Centre of Exercise and Sport Science Research, Edith Cowan University,
Joondalup, Western Australia, 2Centre for Exercise and Sport Science,
Edith Cowan University, 3Edith Cowan University
Mid-thigh pull testing is a popular laboratory technique that has consistently been
proven to be a reliable method for assessing key strength indicators related to
sports performance. Due to equipment limitations the use of this test is often
limited to laboratory-based settings and to date is not often performed in the
field because of the limited portability of the testing equipment. PURPOSE:
To assess the reliability of a portable mid-thigh pull and force-plate testing
apparatus. METHODS: The reliability of a custom made potable mid-thigh pull
testing apparatus was tested with 23 Junior Surfers (Age= 16.3±1.2 y; Body mass=
58.8±9.0; height=168.2±7.6 cm; Σ7 skinfold=43.5±17.6). All subject performed the
isometric mid-thigh pull after a dynamic warm-up and one familiarization trial. A
total of two maximal effort isometric mid-thigh pulls were collected on a custom
portable isometric mid-thigh pull system that was coupled with a force platform
that sampled at 600 Hz. If the PF values achieved were >250 N from the first
trial additional trials were performed. All Force time curves were assessed for
several key characteristics including peak force (PF), average force (AF), peak rate
of force development (PRFD), and isometric impulse from 0-200ms (200IMP).
Reliability was calculated with the use of the coefficient of variance (CV%),
intraclass correlation (ICC) and 90% confidence interval (90%CI) for all force-time
curve variables assessed. Acceptable reliability was determined when a measure
met both an ICC > 0.70 and a CV% < 15%. RESULTS: The PF was determined to
be highly reliable based upon the high ICC (ICC=0.99, 90CI=0.98-1.00; CV%=2.2,
90%CI=1.8-3.0). AF was also found to meet the established criteria for reliability
(ICC=0.97, 90CI=0.93-0.98; CV%=2.2, 90%CI=1.8-3.0). 200IMP was also found to
meet the criteria for reliability by demonstrating a high ICC (0.87, 90%CI=0.730.93) and adequate CV% (8.8, 90%CI=7.0-11.9). PRFD met the minimum criteria
for the ICC (0.84, 90%CI=0.7-0.92), but failed to achieve a CV% that would be
considered reliable (CV%=20.5, 90%CI=16.2-28.3). CONCLUSION: A portable
mid-thigh pull apparatus when employed with a portable force plate can yield
reliable PF, AF, and 200IMP values in junior surfers. PRACTICAL APPLICATIONS: Strength and conditioning professionals can reliably collect PF, MF, and 200IMP
data in a field-based environment with the use of a portable mid-thigh pull
and force plate apparatus. Since PRFD failed to reach reliability standards this
assessment should be reserved for laboratory-based assessments. Saturday, July 13, 2013, 9:00 AM - 9:15 AM
COMPARATIVE GONIOMETRY-DERIVED Q-ANGLES FOR RELAXED VS.
CONTRACTED QUADRICEPS FEMORIS MUSCLES
L. Weiss1, B. DeForest1, S. Nichols1, B. Schilling1, M. Paquette1
1
The University of Memphis
A large or small quadriceps angle (Q-angle) is assumed to be indicative of the
presence of genu valgum (knock-knee) or genu varum (bow-leg), respectively.
Surface goniometry has been used to measure Q-angle, but contractile state of
the quadriceps femoris (quad) muscles is not universally controlled. PURPOSE:
To determine the respective stability reliability, precision, and comparative
difference in Q-angles using surface goniometry when the quad muscles are
either relaxed or isometrically contracted. METHODS: Twenty-eight apparentlyhealthy young, rested men (n=19) and women (n=9), 20-32 years of age
(M±sd, 23.1±2.9), who had readily-palpable anterior superior iliac spines (ASIS),
were recruited for the investigation. The Q-angle of both knees in relaxed and
contracted quad conditions was obtained on two separate occasions either
24 or 48 hours apart. Q-angle was operationally defined as the superior angle
formed by intersecting lines running from the ASIS to the center of the patella,
and from the center of the tibial tuberosity to the center of the patella on
each side of the body. Following landmark identification and feet fixation (i.e.,
taped together) in a neutral position, an extendable-arm goniometer (Lafayette
Instruments) was used to measure the Q-angle for both left and right legs with
relaxed and maximally isometrically-contracted quad muscles. Stability reliability
was determined by intraclass correlation (ICC2-way random). Precision, or the
minimum-detectable real difference, was determined by limits of agreement
(LOA95%, 2.77 X standard error of measurement). Comparisons for relaxed
vs. contracted conditions were made by dependent t-tests using a Bonferroni
procedure with an adjusted α level of 0.0125 (0.05/4), while effect size (ES) was
estimated using Cohen’s d for repeated measures. RESULTS: ICCs for Q-angle
measurements were as follows: left-leg relaxed = 0.94, right-leg relaxed = 0.94,
left-leg contracted = 0.86, right-leg contracted = 0.91. LOA95% for estimating
precision were as follows: left-leg relaxed = 2.8°, right-leg relaxed = 3.1°, left-leg
contracted = 3.9°, right-leg contracted = 3.6°. During the first session, left-leg
relaxed Q-angle (M±sd, 12.8±3.95°) was greater than (p≤0.001, ES=2.4) when
contracted (10.0±3.88°), and right-leg relaxed Q-angle (14.0±4.30°) was greater
than (p≤0.001, ES=2.8) when contracted (10.8±4.32°). During the second session,
left-leg relaxed Q-angle (12.4±4.01°) was greater than (p≤0.001, ES=3.1) when
contracted (9.3±3.58°), and right-leg relaxed Q-angle (13.6±4.52°) was greater
than (p≤0.001, ES=3.2) when contracted (10.5±4.17°). CONCLUSIONS: Q-angle
may be reliably obtained with a precision of 4° or better using surface goniometry
in young men and women with either relaxed or isometrically contracted quad
muscles. Furthermore, Q-angles are greater when the quads are relaxed rather
than contracted. PRACTICAL APPLICATION: Although reliable and reasonably
precise Q-angle measurements may be obtained using surface goniometry,
standardized reporting regarding the contractile condition of the quadriceps
femoris muscles is needed in order for meaningful comparisons to be made.
Saturday, July 13, 2013, 9:15 AM - 9:30 AM
RELATIONSHIP BETWEEN RATING OF PERCEIVED EXERTION, RESISTANCE
EXERCISE INTENSITY, AND FATIGUE
L. Vasquez1, J. Alley1, C. Goodman2, J. Paul1, J. McBride2
1
Appalachian State University, 2Appalachian State
University/Neuromuscular & Biomechanics Laboratory,
Department of Health, Leisure & Exercise Science, Boone, NC
To normalize ratings of perceived exertion (RPE) during exercise, multiple scales
have been developed which offer a practical method to measure subjective effort.
Perceived exertion has been defined as the subjective intensity of effort, strain,
discomfort, and/or fatigue experienced during the exercise task. RPE scales have
been found to relate to intensity during aerobic exercise, however, the relationship
between RPE and resistance exercise intensity and fatigue is unclear. PURPOSE: To
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
further examine the relationship between RPE scales to resistance exercise
intensity (% of one repetition maximum (1RM)) and fatigue (fatigue index) in male
subjects knowledgeable in resistance training. METHODS: Twelve subjects (age:
21.9 ± 1.3 yrs, body mass: 77.8 ± 8.0 kg, height: 177.9 ± 6.4 cm, 1RM: 124.9 ± 32.9
kg) performed sets of a traditional back squat at three different intensities (50%,
70%, and 90% of 1RM) for 3 repetitions and to volitional failure (50-3, 50-F, 70-3,
70-F, 90-3, 90-F). RPE using the Borg 6-20 scale was provided by the subjects
immediately following each set. All conditions were performed on a force plate in
order to provide total work per set and fatigue index was calculated as the number
of repetitions completed per set relative to the number of repetitions completed
to volitional failure. RESULTS: The number of repetitions (50-F = 36.6 ± 9.4, 70-F =
15.6 ± 5.0, 90-F = 5.9 ± 2.9, p ≤ 0.05) completed and total work (50-F = 31,224.2 ±
8,148.5 J, 70-F = 15,758.3 ± 7,585.8 J, 90-F = 6,003.5 ± 2,180.7 J) were significantly
different between 50-F, 70-F, and 90-F although no significant differences were
found between RPE (50-F = 16.7±2.2, 70-3 = 16.5 ± 1.6, 90-3 = 17.4 ± 1.5) and fatigue
index. RPE (50-3 = 9.5 ± 1.6, 70-3 = 11.7 ± 1.1, 90-3 = 15.3 ± 1.8) and fatigue index
(50-3 = 9.1 ± 1.0, 70-3 = 21.0 ± 7.0, 90-3 = 60.0 ± 23.0) were significantly different
between 50-3, 70-3 and 90-3. CONCLUSION: In agreement with previous results
this investigation indicates that RPE does increase as intensity increases, but only
when performing sets to a predetermined number of repetitions. Our findings also
agree with previous investigations that RPE must increase linearly as a function
of time (repetitions completed) because the physiological and psychological
effect of fatigue (fatigue index) and thus does not differentiate between varying
intensities. In the current investigation, when comparing the amount of work
performed, the sets completed to a predetermined number of repetitions were
similar unlike the RPE values. Alternatively, during the sets to volitional failure all
demonstrated similar RPE values, but significantly different amounts of work. This
contrast demonstrates that RPE may have little relationship to intensity, repetitions
completed, or to work, but does exhibit a strong relationship with fatigue. PRACTICAL APPLICATIONS: Performing a set of 3 repetitions at 50 or 70% would
have little significance with regards to the accepted practice of resistance training
program design in which a set at a low intensity would not be performed at the
same number of repetitions as a set at a high intensity. Without a relationship
between RPE values and the sets completed to volitional failure, we are not able to
conclude that RPE can be a helpful measure of resistance training intensity when
it does not count for fatigability during low intensity bouts of resistance training.
Saturday, July 13, 2013, 9:30 AM - 9:45 AM
RELATIONSHIP BETWEEN SQUAT STRENGTH AND KNEE POSITION
DURING DROP JUMP LANDINGS
C. Goodman1, T. Haines1, K. N. Kijowski2, J. McBride1
1
Appalachian State University/Neuromuscular & Biomechanics Laboratory,
Department of Health, Leisure & Exercise Science, Boone, NC,
2
Appalachian State University
PURPOSE: The purpose of this study was to identify the relationship between
squat one repetition maximum (1RM) strength and knee position when landing
from drop jumps (DJ) of varying heights. Valgus and varus are terms to describe
frontal-plane knee positions. Valgus is considered a medial deviation of a joint,
while varus is a lateral deviation of a joint. Factors such as lack of strength in
the gluteal muscles, muscle strength imbalances, or deficiency in general lower
body strength relative to body mass may be reasons behind these knee deviations
when squatting and landing from jumps. The concern about valgus knee angles
during jumping is due to the possible relationship of this phenomenon to anterior
cruciate ligament (ACL) injury. Besides the acute injury of an anterior cruciate
ligament tear, valgus knee position has also be attributed to more chronic injury
such as osteoarthritis. Thus, the contribution of increased leg strength might be
an important component to maintaining knee position with drop jump landings.
METHODS: Eleven male subjects completed a 15 minute familiarization session to
ensure they were comfortable and aware of proper DJ protocol. DJ heights were
randomized at 20 cm, 40 cm and 60 cm and a countermovement jump (CMJ)
was performed as well. Reflective markers were placed on the greater trochanter,
lateral epicondyle and the lateral mallelous of both the left and right legs to track
joint locations and knee angles utilizing three-dimensional videography for two
trials of each jump type. Following the jumps a one repetition maximum (1RM)
in the squat was completed. RESULTS: The squat 1RM was significantly correlated
with the varus/valgus knee angles while landing from jumps at 20 cm (0.867),
40 cm (0.863), 60 cm (0.874) and CMJ (0.765). Subjects exhibiting a greater
1RM showed higher levels of knee varus when landing. CONCLUSION: Previous
research has identified the relationship between absolute strength of men and
women and the tendency for females to land in a more valgus position than their
male counterparts. By establishing a significant correlation, this data could now be
applied to future research. The varus landing stance of males may be an important
factor as to why they experience less ACL injuries every year, as a valgus knee
angle has been shown to put the ACL at an increased risk for tearing. If strength
is a determining factor for more neutral knee angles at landing, it is possible that
by gaining strength and increasing the 1 RM of an individual, values will become
more normalized, pointing to the need for examination of a training protocol and
its effects on knee angles at landing. PRACTICAL APPLICATIONS: By improving
the absolute strength of an individual, it is possible that drop-jump landing knee
angles will become more favorable, potentially leading to a decrease in injury
rates and improved jumping, which could be related to an increase in performance
if jumping is a required part of a person’s sport or activity.
Saturday, July 13, 2013, 9:45 AM - 10:00 AM
QUANTIFICATION OF UNLOADING FORCE AND INFLUENCE ON POWER
OUTPUT AND IMPULSE DURING JUMPING
J. Alley1, J. Paul1, L. Vasquez1, C. John2, J. McBride3
Appalachian State University, 2Appalachian State University,
Appalachian State University/Neuromuscular & Biomechanics Laboratory,
Department of Health, Leisure & Exercise Science, Boone, NC
1
3
PURPOSE: Determining the load at which peak power (PP) is
maximized in human movement has been examined utilizing three
primary models: the elbow, the bench press and the jump squat. Some
additional studies have examined the power clean and squat. Most investigations
present loading that maximizes power output as a function of some maximal
force output measurement (i.e. maximal muscle fiber isometric force, maximal
isometric elbow flexion force, etc.) and has been reported to be at a load
somewhere between 25% and 45% of those measures. Determining the load at
which PP occurs during vertical jumping requires performing jumps in unloaded
conditions. This has led to difficulties in interpretation of the results of previous
investigations due to the lack of quantification of the unloading conditions. The
purpose of this investigation was to present the pattern of unloading in the
various conditions to elucidate its influence on PP. METHODS: Fourteen male
subjects (age = 21.5 ± 1.6 yrs, body mass = 78.7 ± 8.2 kg, height 1.77 ± .056 m, 1RM
= 128.1 ± 24.6 kg, 1RM/body mass = 1.6 ± 0.3) with at least two years of resistance
training experience completed countermovement jumps (CMJ) and static jumps
(SJ) at 0%, 15%, 30%, 45%, and 60% of maximal dynamic strength (MDS = 1RM +
[Body Mass – Shank Mass]) in a randomized order. All testing was performed with
subjects standing on a force plate while two linear position transducers attached
to a bar were utilized to produce displacement-time, force-time, velocity-time,
and power-time curves. Jump height (JH), peak force (PF), peak velocity (PV)
and peak power (PP) were measured for each jump during the concentric phase. Relative net vertical impulse (VI) during the propulsive phase of each jump was
also determined. A strain gauge in series with the unloading apparatus was used
to quantify unloading force. RESULTS: The highest PP in both CMJ and SJ was
observed at 45% of MDS (0% CMJ PP = 4288.2 ± 1415.1 W, 15% CMJ PP = 4761.7
± 1450.9 W, 30% CMJ PP = 5052.9 ± 1092.3 W, 45% CMJ PP = 5246.0 ± 1024.5
W, 60% CMJ PP = 4922.6 ± 995.8 W; 0% SJ PP = 3601.0 ± 1133.3 W, 15% SJ PP =
4052.3 ± 1113.2 W, 30% SJ PP = 4708.3 ± 1145.2 W, 45% SJ PP = 4900.9 ± 872.5 W,
60% SJ PP = 4390.2 ± 800.9 W). Unloading force ranged from 665.7 ± 57.6 N at
0% of MDS to 386.5 ± 51.7 N at 15% of MDS to 86.9 ± 71.9 N for 30% of MDS and
varied in relation to jump phase. There was a non-significant correlation between
relative PP and JH (0% CMJ JH = .68 ± .14 m, 15% CMJ JH = .60 ± .12 m, 30% CMJ
JH = .46 ± .06 m, 45% CMJ JH = .37 ± .07 m, 60% CMJ JH = .26 ± .07 m; 0% SJ
JH = .58 ± .13 m, 15% SJ JH = .51 ± .12 m, 30% SJ JH = .41 ± .10 m, 45% SJ JH = .34
± .05 m, 60% SJ JH = .23 ± .06 m; r = 0.01). There was a significant correlation
between JH and VI with all loading conditions in both the CMJ and SJ (0% CMJ
VI = 3.54 ± .63 m/s, 15% CMJ VI = 3.17 ± .48 m/s, 30% CMJ VI = 2.88 ± .26 m/s,
45% CMJ VI = 2.86 ± .50 m/s, 60% CMJ VI = 2.90 ± .50 m/s; 0% SJ VI = 3.29 ± .43
m/s, 15% SJ VI = 2.90 ± .37 m/s, 30% SJ VI = 2.65 ± .27 m/s, 45% SJ VI = 2.65 ±
.38 m/s, 60% SJ VI = 2.60 ± .37 m/s; r = 0.61, p ≤ 0.05). The highest VI and JH in
the CMJ and SJ were observed at 0% of MDS. CONCLUSION: This investigation
has again shown that PP occurs at a load of approximately 25 to 45% of maximal
force capabilities. Future investigations should attempt to quantify the amount
of unloading utilized in an investigation to allow for better context for data
comparison. In addition, VI actually appears to be the best predictor of JH in
comparison to PP. PRACTICAL APPLICATIONS: The lack of relationship between
PP and JH may call into question the importance of determining the load at which
PP occurs since it does not appear that PP relates to athletic performance in a
consistent pattern.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Saturday, July 13, 2013, 10:00 AM - 10:15 AM
RELATIONSHIP BETWEEN SQUAT STRENGTH AND STATIC,
COUNTERMOVEMENT AND DROP JUMP PERFORMANCE
K. N. Kijowski1, C. Goodman2, D. P. Knorr1, J. Alley3, J. Paul3, C. Capps1,
N. Triplett2, J. McBride2
1
Appalachian State University, 2Appalachian State University/Neuromuscular &
Biomechanics Laboratory, Department of Health, Leisure & Exercise Science,
Boone, NC, 3Appalachian State Univeristy
PURPOSE: The purpose of this study is to examine the relationship between
squat strength and jump performance. Squat strength is indicative of overall
force application and has previously shown positive correlations with explosive
movements (jumping, sprinting). The jumps can be analyzed through the use of
a force plate and potentiometers, producing our variables of interest, peak power
and peak force. These variables allow consideration of the force application and
how quickly it is applied. Thus, the peak force and peak power produced during the
concentric phase of a static, countermovement, and drop (40cm) jump is a good
indication of overall vertical performance capabilities. METHODS: 10 male subjects
between the ages of 18 to 25 were recruited from Appalachian State University
with at least 2 years of prior resistance training experience. Subjects were tested
during a single session consisting of height (183.52 ± 9.01 cm) and body mass
(79.05 ± 7.27 kg) measurements and then performing vertical jumps and squat
1RM testing (99 ± 18.38 kg). Jump testing consisted of 9 total jumps in randomly
selected order, 3 countermovement, 3 static, and 3 drop jumps from 40cm. Jumps
were separated by 25-30sec of rest, with 3 minutes of rest between every three
jumps. All jumps were performed on a force plate which was utilized to calculate
peak power and peak force during the concentric phase of the jump. The subjects
rested for at least 5 minutes and then started the squat testing. Subjects were
allowed 2 sets of 8-10 repetitions at 30%, 4-6 repetitions at 50%, 2-4 repetitions
at 70%, and 1 rep at 90% of a recommended 1RM or 1.5-2.5x their bodyweight,
depending on training status. The individuals were allowed up to 3-4 attempts at
increasing weights to obtain a 1RM. Subjects were asked to lower the bar to a knee
angle of at least 80 degrees. RESULTS: Squat strength was significantly positively
correlated with peak power and peak force during CMJ (0.62, 0.71, respectively)
and SJ (0.85, 0.75, respectively). However only weak relationships exist when
comparing these variables to drop jump performance (0.43, 0.06, respectively).
CONCLUSION: The positive correlations between squat strength and peak power
and force during CMJ and SJ performance display the importance of overall squat
strength. The ability to generate more force production during squat performance
transfers to greater jumping performance. An increase in peak power indicates a
greater ability to perform explosive movements, jumping and sprinting. The lack
of relationship of these variables displayed during the drop jump performance
indicates the possible variation in the technical aspect of the jump. This includes
variation in absorption during landing and then a quick transfer over to jumping.
PRACTICAL APPLICATION: Increasing lower body strength is likely to result in
increased SJ and CMJ performance, however, this relationship does not appear to
relate to DJ performance. Thus, other factors such a plyometric training may have
a more significant influence on DJ performance as opposed to purely strength
training.
Saturday, July 13, 2013, 10:15 AM - 10:30 AM
EFFECTS OF SHORT-TERM RESISTANCE TRAINING AND SUBSEQUENT
DETRAINING ON CONTRALATERAL STRENGTH
P. B. Costa1, T. J. Herda2, A. Herda3, J. Cramer4
1
California State University - San Bernardino / Human Performance Laboratory,
2
University of Kansas / Biomechanics Laboratory, Lawrence, KS,
3
University of Kansas Medical Center, 4University of Nebraska - Lincoln
Short-term resistance training has been shown to increase muscle strength and
isokinetic performance after only a few days of training. However, no studies
have investigated the effects of short-term training on contralateral strength.
Purpose: To examine the effects of three days of dynamic constant external
resistance (DCER) and subsequent detraining on the contralateral strength of the
untrained limb. Methods: Thirty-one apparently-healthy untrained men (mean ±
SD age = 22.2 ± 4.2 yrs; body mass = 77.9 ± 12.9 kg; height = 173.9 ± 5.4 cm)
were randomly assigned to a DCER training group or a control group. Subjects
visited the laboratory eight times, the first visit was a familiarization session, the
second visit was a pre-training assessment, the subsequent three visits were for
training sessions (if assigned to the training group), and the last three visits were
post-training assessments 1, 2, and 3 (i.e., 48 hrs, 1 wk, and 2 wks after the final
training session). The training group performed DCER leg extension exercise on
the dominant leg for three sets of ten repetitions in each of the three days of
training. The control group did not take part in the training intervention. Muscle
strength of the untrained leg was quantified via a DCER one repetition maximum
strength test (1RM). Results: There was a significant two-way interaction for
time × group (p < 0.05) for 1RM strength of the untrained leg. Post-hoc pairwise
comparisons for the marginal means indicated that 1-RM increased from pre- to
post-training assessment 1 for the training group only, and remained elevated
during post-training assessments 2 and 3 (p < 0.05). There were no differences in
1-RM strength for the DCER group among post-training assessments 1, 2, and 3 (p
> 0.05). No changes were found for the control group (p > 0.05). Conclusions: The
primary finding of this study was that contralateral strength can be increased with
three days of contralateral training. Strength in the untrained leg increased 15.6%
from the pre-training assessment after only three days of training the opposite
leg and remained elevated for two weeks of detraining. Practical Applications:
Possible strength gains from short-term resistance training have important
implications in clinical rehabilitation settings, sports injury prevention, as well as
in other allied health fields such as physical therapy, occupational therapy, and
athletic training. The findings from the current study suggest training an uninjured
leg might benefit an injured untrained limb during short-term injury or prior to
surgical interventions.
Saturday, July 13, 2013, 10:30 AM - 10:45 AM
THE EFFECT OF INITIATING A STRENGTH PROGRAM ON LOWER
BODY SPEED STRENGTH IN ELITE SURFERS
J. M. Sheppard1, S. Nimphius2, T. Tran3, L. Lundgren3, G. Haff3, A. M. Dunn4
1
Surfing Australia & Edith Cowan University, 2Centre for Exercise and Sport
Science, Edith Cowan University, 3Centre of Exercise and Sport Science
Research, Edith Cowan University, Joondalup, Western Australia,
4
Surfing Australia
PURPOSE: Although surfing has been a fully professional, international sport for
several decades, the adoption of strength and conditioning methods amongst the
sport’s elite could be described as being in its infancy. Typically, training approaches
for surfing do not acknowledge a considerable strength requirement, instead
favoring high volumes of proprioceptive training, flexibility, and endurance. To the
authors’ knowledge, there is no data on the effect of strength training methods
with a surfing population despite previous investigations finding that speed
strength and maximal strength qualities discriminate between higher and lower
performers in competitive surfers. The purpose of this study was to evaluate the
effect of strength training on lower body power in elite pro-junior (under 20) and
professional (World Tour) surfers over a 6 month time period. METHODS: Eleven
athletes (19.5±2.2 years, 1.72 m ±0.09 m, 67.3±8.6 kg), including 3 females and 8
males, voluntarily engaged in formal strength training in addition to their in-water
surf training and competition. Prior to the study period, each athlete engaged
in 3 months of training to develop a minimum level of athletic competence in
major movement patterns to prepare for advancement into the strengthtraining program, as their previous experience in strength training was minimal
throughout the group. Depending on each individual’s competitive schedule,
athletes completed between 1 and 4 strength-training sessions per week for a
6-month time period, such that they averaged 2 sessions per week over the study
duration (48 sessions). Over the training time period, athletes were progressed
on an individual basis on the main lifts of bilateral and unilateral squat, snatch,
and upper-body push and pulling exercises, as well as accessory exercises. Prior
to and at the conclusion of the training period, athletes were assessed for their
lower body speed strength through an unloaded jump squat performed on a force
platform (500 Hz, Ballistic Measurement System, Adelaide Australia), with the
Peak Force (PF), Peak Velocity (PV), and Displacement (DISP) retained as primary
variables of interest. Using population-specific typical error data for the jump
squat (PF: 37 N, PV: 0.01 m/s, DISP: 0.01 m) and a reference value for likelihood of
change of 0.2 x group SD, smallest worthwhile change statistics were calculated
to reflect the probability that observed results were clinically positive. In addition,
paired samples t-tests with an alpha of p≤0.05 and effect sizes (Cohen’s d) were
calculated. RESULTS: Improvements in PF (172 N, 12%) and PV (0.3 m/s, 11%) were
97% likely to be clinically positive and 3% likely to be clinically trivial, whilst DISP
improvements (3.5 cm, 8%) were 89% likely to be clinically positive and 11% likely
to be clinically trivial. PF, PV, and DISP changes were all considered statistically
significant and to be of moderate to large magnitude of gain (p=0.004, d=0.58; p
=0.003, d=0.92; p=0.039, d=0.41, respectively). CONCLUSIONS: Strength training
can positively influence speed strength qualities in elite competitive surfers.
PRATICAL APPLICATIONS: Considering that speed strength and maximal strength
have been validated as important physical qualities in competitive surfers, strength
training methods such as squats and Olympic lifting should be integrated into the
overall training of surfers, with a view to increase strength and speed strength
qualities.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Saturday, July 13, 2013, 10:45 AM - 11:00 AM
EFFECT OF WARM-UP DEVICES ON BAT VELOCITY AND PERCEPTION OF
HEAVINESS AND SPEED OF SWING OF COLLEGIATE BASEBALL PLAYERS
D. Szymanski1, T. Donahue1, B. Stover1, D. Boyce1, L. Africa1,
M. Greenwood2, J. Beam3
1
Louisiana Tech University, 2Texas A&M University,
3
University of New Mexico
PURPOSE: To examine the effect of various warm-up (WU) devices on bat velocity
(BV), and perception of heaviness and speed of swing of collegiate baseball
players. METHODS: Twenty Division I college baseball players volunteered for
this study and were randomly placed into 1 of 7 groups to swing 7 different WU
devices over 7 days. WU devices were a: 33 in, 30 oz standard aluminum baseball
bat, 30.5 in, 64 oz flexible weighted implement (FW), 30.5 in, 48 oz flexible
weighted implement, 24 oz weighted ceramic cylinder (added to standard bat),
12 oz dynamically weighted plastic cylinder (added to standard bat), 39.5 in, 15 oz
end loaded WU device, and 39.5 in, 15 oz dynamic WU device. After a 10 minute
active, dynamic WU, players took 2 x10 practice swings with a standard bat, and
then sat on a bench in the batting cage area for 5 minutes. A BatMaxx 5500 then
recorded WU device velocity for 6 consecutive swings. Immediately after the WU
swings, players subjectively rated the heaviness of the WU device to the standard
bat. Then, once in the batter’s box, players swung the standard baseball bat 2
times “comfortably” before the experimental trials. A SetPro SPRT5A recorded
standard BV from 3 maximal effort swings with 20-seconds of rest between
swings while hitting a baseball off a batting tee. Subjects were not allowed to
practice swinging between trials. Immediately after each of the 3 swings, players
subjectively rated how fast they swung the standard bat. The testing order of
different devices was randomly assigned to each group. Each subject was tested
on 7 days, using 1 device per day. RESULTS: As expected, there was a significant
difference (p < 0.05) between all of the WU device’s swing velocities compared
to the standard bat WU swing velocity. There was a significant within-subjects
main effect for the WU opinion of “heaviness of bat” data. After comparing
each value to the standard bat heaviness rating, all WU devices had significantly
different ratings than the standard bat WU heaviness rating. One-way repeated
measures ANOVA indicated no significant differences between the mean BV after
using any of the 7 WU devices. The only significant within-subjects main effect
for the “speed of swing” rating compared to the standard bat was the 64 oz FW. CONCLUSION: Although all of the WU devices swing velocities were different
than the standard BV in the on-deck circle and they also subjectively felt different
than the standard bat, results indicate that WU devices varying from 15 to 64 oz
did not change mean BV of a standard 33 in, 30 oz baseball bat for collegiate
baseball players. PRACTICAL APPLICATIONS: Based on BV, players can use any of
the 7 WU devices in the on-deck circle and maintain their BV. Therefore, personal
preference as to which WU device to use in the on-deck circle is recommended. The advantage of the WU with a weighted device was thus psychological and
not physiological. ACKNOWLEDGMENT: We would like to thank Momentus Sports
(Mount Pleasant, IA, USA) and Bats Limited (Hewitt, TX, USA) for partially funding
this study.
Saturday, July 13, 2013, 11:00 AM - 11:15 AM
IS THERE A PACING STRATEGY DURING A 505 CHANGE OF
DIRECTION TEST IN ADOLESCENTS?
S. Nimphius1, T. Spiteri2, L. Seitz1, E. Haff1, G. Haff3
Centre for Exercise and Sport Science, Edith Cowan University,
Centre for Exercise and Sport Science Research, Edith Cowan University,
3
Centre of Exercise and Sport Science Research, Edith Cowan University,
Joondalup, Western Australia
1
2
One basic fitness component often measured in a testing battery is change of
direction (COD) ability. The ability for an adolescent to change direction has had
minimal focus in health or sport science research in comparison to other common
fitness components. A common test for COD is the 505 COD test that is intended
for a high velocity running entry followed by a 180 degree change of direction.
This test requires a great deal of eccentric strength especially when entering at a
high velocity. PURPOSE: To examine if adolescents use a pacing strategy to handle
the difficult change of direction during the 505 COD test. METHODS: Twenty male
and 19 female adolescents (age: 13.4 ± 0.4 years; height: 161.8 ± 6.7 cm; body mass:
59.9 ± 11.1 kg) volunteered to participate in this study. Maximal acceleration ability
was assessed using the 10 m split from a 30 m sprint. The traditional 505 test was
used to assess COD ability. Reliability of 10 m sprint times and COD performance
were assessed by intraclass correlation coefficient (ICC) and coefficient of variation
(CV). The presence of a pacing strategy was assessed by comparing the 10 m
sprint split time to the 10 m split prior to the “505” change of direction by a paired
T-test and magnitude of effect (ES). Further, the relationship between COD deficit
(505 time minus 10 m sprint time) relative to COD performance was examined by
Pearson’s product moment correlations with 90% confidence intervals (90%CI)
using log-transformed data. RESULTS: There was a high level of reliability of 10 m
sprint time, 10 m split in the 505 and 505 times in these adolescents (ICC: 0.820.91; CV: 2.1-3.5%). The 10 m split during a 505 entry was significantly slower than
the 10 m split of a 30 m sprint (p < 0.001, ES = 0.55) with adolescents reducing
their time by 4.05% ± 3.77% in anticipation of entering the 505 portion of the
COD test. In addition, there was a very strong relationship (r = 0.78, 90%CI:0.65
to 0.87) between COD deficit and 505 performance. CONCLUSION: The results
demonstrate that some adolescents slow their entry running velocity even before
entering the “505” portion of the test where performance time is derived in the
traditional 505 test. Further, the assessment of the “COD deficit” is an indicator
of actual COD ability by inherently controlling for sprint ability. Although COD
deficit explains approximately 60% of the variance in 505 time it seems to be a
more specific measure of isolating COD ability with respect to, instead of despite
their individual speed capabilities. PRACTICAL APPLICATIONS: Some adolescents
may use a pacing strategy when faced with a difficult COD task and their ability
to change direction can be assessed independent of their speed by expressing it
as a COD deficit. Saturday, July 13, 2013, 11:15 AM - 11:30 AM
THE COMBINED EFFECTS OF EXERCISE, DIET, AND A MULTI-INGREDIENT
DIETARY SUPPLEMENT ON BODY COMPOSITION AND ADIPOKINE
CHANGES IN OVERWEIGHT ADULTS
S. M. Arent1, P. Dolan1, J. Pellegrino1, H. Lopez2, T. Ziegenfuss2,
A. Walker1, S. Woeller1
1
Rutgers University, Human Performance Laboratory,
2
Center for Applied Health Sciences
While many supplements are promoted for weight and fat loss benefits, very
few of them undergo finished-product research to examine efficacy. PURPOSE:
To determine the effect of a dietary supplement containing raspberry ketone,
capsaicin, caffeine, garlic, and Citrus aurantium on body composition, hip and
waist girth, and adipokines in conjunction with an 8-week diet and exercise
program. METHODS: Overweight males and females (N=30; Mage = 38.2 + 10.3
yr, Mweight = 88.12 + 16.0 kg, M%BF = 38.3 + 7.6%) completed this randomized,
placebo-controlled, double-blind study. Subjects consumed 4 capsules per day of
the supplement (EXP; n = 15) or placebo (PLA; n = 15). Following baseline testing,
both groups underwent 8 weeks of daily supplementation, a calorie restricted
diet (500 kcal < RMR x 1.4), and three session per week of supervised progressive
exercise training. Training consisted of 3 sets of 5-7 resistance training exercises
at an intensity of 90-100% 10RM followed by 30 min of aerobic exercise at an
intensity of 70-85% HRR. Body composition (via BOD POD), hip and waist girth,
as well as select adipokines (adiponectin, resistin, leptin, IL-6) were assessed
at baseline, week 4, and post-intervention (T1, T2, & T3). RESULTS: Significant
decreases in weight (-2.3 + 3.5 kg, P<.001), fat mass (-3.5 + 2.4 kg; P<.001), and
%BF (-3.4 + 2.2%, P<.001), and a significant increase in LBM (1.6 + 2.0 kg; P<
.001) were seen from T1 to T3. Waist (-8.7 + 5.8 cm, P<.001) and hip (-6.2 + 6.3
cm, P<.001) girth were also reduced. There were no significant Group differences
(P>.53) for the body composition or girth measurements, though the Time x
Group interaction approached significance for waist girth (P=.10). Significant
decreases in IL-6 (P=.018), leptin (P=.005), and resistin (P=.011) were seen from
T1 to T3 across groups. There was also a significant Time x Group interaction for
adiponectin (P=.038), with EXP displaying a 46% increase in adiponectin from T1
to T3 while PLA remained stable. There were no other significant Group effects
(P>.30). Changes in leptin were positively correlated with changes in weight (r=.46,
P=.015) and waist girth (r=.39, P=.04), and approached significance for correlations
with changes in LBM (r=.35, P=.068), FM (r=.36, P=.058), and hip girth (r=.37,
P=.054). CONCLUSIONS: The exercise and diet program produced significant
improvements in body composition, FM, LBM, and girth. With the exception of
waist girth, these changes were not enhanced by supplementation with EXP. It is
possible that intensity of the program and degree of caloric restriction mitigated
potential supplement effects. The significant improvements in adipokines support
the utility of exercise, diet, and fat loss for impacting inflammatory biomarkers.
Reductions in leptin were associated with changes in weight loss variables and
imply improved sensitivity. Despite no Group differences for body composition,
the improvement in adiponectin with EXP suggests a unique health mechanism.
PRACTICAL APPLICATIONS: A combined resistance training and aerobic
exercise program, coupled with dietary intervention, successfully improves body
composition, girth, and adipokine status in overweight individuals. Though the
addition of the proprietary supplement did not enhance most body composition
changes, it did increase positive adaptations in adiponectin which could have
important health implications. ACKNOWLEDGEMENTS: Funding provided by
Ultimate Wellness Systems, Inc.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Saturday, July 13, 2013, 11:30 AM - 1:00 PM
Poster: 1
DOES INGESTING A SODIUM-SODIUM CITRATE BEVERAGE PROVIDE RAPID
REHYDRATION FOR ATHLETES GIVEN 2 HOURS TO REHYDRATE AFTER LOSING
2.5% OF THEIR BODY MASS VIA PASSIVE DEHYDRATION?
K. A. Brooks1, J. G. Carter2, J. Dawes1
1
Texas A&M University Corpus Christi, 2Texas A&M University
INTRODUCTION: Research has shown that many athletes are continually in a state
of dehydration. This impairs performance, and increases the chance of heat-related
illness. Using sodium supplementation to increase fluid absorption and stimulate
the thirst mechanism has proven effective in rehydration. PURPOSE: The purpose of
this study was to determine if ingesting a beverage containing 1,780 mg of sodium
and 2,953 mg of sodium citrate would increase the rehydration rate for previously
hypohydrated individuals prior to exercising in a heated environment during
aerobic exercise. METHODS: Five division one female soccer athletes participated
in the study. The subjects had the following descriptive statistics: Age 19 ± 0.7 yr,
Height 162.3 ± 4.6 cm, Weight 63.2 ± 8.1 kg, %BF 23.68 ± 9.2%, and VO2max 60.2 ± 5.1
ml∙kg-1∙min-1. The study required subjects (N=5) to run the experimental protocol
twice. Fluid intake was matched for each condition. Prior to running to exhaustion
at 70% of their VO2max on a treadmill in a heated chamber, the subjects were
passively dehydrated and loss 2.5% of their body mass. The subjects were given 2
hours to rehydrate via either a placebo (10 mmol Na+∙L-1) or the supplement (164
mmol Na+∙L-1). After medical clearance, subjects performed a graded exercise test
to determine VO2max. ACSM equations were used to determine running speed at
70% of VO2max. Testing conditions consisted of the subjects running at 70% of their
VO2max until exhaustion while in a heated chamber at 90° Fahrenheit. The study
employed a double-blind, repeated measure, within subject protocol. The treadmill
protocol consisted of a five minute warm-up (3 minutes at 40% of their VO2max and
2 minutes at 55% of their VO2max), running to exhaustion at 70% of VO2max, and
a 10 minute cool down at 3.0 mph. Every five-minute period on the treadmill,
variables were assessed. RESULTS: Results indicated that there were no significant
differences between conditions for hydration time. There were no significant
differences between conditions for urine specific gravity between conditions
pre exercise or during weight cutting. A significant difference (p<0.05) in USP
between conditions was found post exercise, with the supplement trial reporting
a higher USP value. CONCLUSION: Skin temperature was lower when hydrated
with the sodium supplemented beverage after sustained aerobic exercise at 70%
of VO2max, in a hot environment. The ability to maintain a lower body temperature
may lead to increased performance through maintenance of blood volume and
a decreased effect of cardiovascular drift. Notably, all of the subjects performed
better on the first treadmill session regardless of the experimental condition (i.e.
placebo or high sodium solution). Absolute conclusions cannot be drawn from
this study. PRACTICAL APPLICATION: Dehydration should be a major concern for
any athlete, especially for those who are performing in hot, humid environments.
Preventative methods such as ingesting a sodium solution, frequent weigh-ins,
and continual education for the athlete should all be employed to avoid any form
of heat illness to the athlete. Practitioners should be aware of the importance
of aerobic conditioning for an athlete while exercising in a hot environment.
Knowledge of warning signs and symptoms, and taking proper precautions to
prevent complications is of importance. Coaches should be aware that athletes
who are less conditioned are at higher risk for heat illnesses; therefore, proper
training and steps towards acclimatization must be employed prior to training in
the heat.
Poster: 2
EFFECTS OF A SODIUM-SODIUM CITRATE BEVERAGE ON SUBSEQUENT RUN
TIME TO EXHAUSTION & RPE IN PREVIOUSLY HYPOHYDRATED SOCCER
ATHLETES IN A HOT ENVIRONMENT DURING AEROBIC EXERCISE
J. G. Carter1, K. A. Brooks2, J. Dawes2
1
Texas A&M University, 2Texas A&M University Corpus Christi
INTRODUCTION: Research suggests that many athletes are in a chronic state
of dehydration. This may not only impair performance, but also increases the
risk of experiencing a heat-related illness. One method shown to be effective
in rehydrating athletes is the use of a beverage containing sodium to increase
fluid absorption and stimulate the thirst mechanism. However, it has yet to be
determined if a supplement containing sodium and sodium citrate is as effective.
PURPOSE: The purpose of this study was to determine if ingesting a beverage
containing 1,780 mg of sodium and 2,953 mg of sodium citrate would increase
subsequent run time to exhaustion and lower RPE in previously hypohydrated
individuals during aerobic exercise. METHODS: Five (n=5) division I female soccer
players (19 ± 0.7 yr, Height 162.3 ± 4.6 cm, Weight 63.2 ± 8.1 kg, %BF 23.68 ±
9.2%, and VO2max 60.2 ± 5.1 ml∙kg-1∙min-1) participated in this study. Subjects were
passively dehydrated in a heated chamber, until they experienced a 2.5% loss in
body mass. Subjects were then given 2 hours to rehydrate via a placebo (10 mmol
Na+∙L-1) or the supplement (164 mmol Na+∙L-1). A double-blind, repeated measure,
within subject protocol was utilized. Each individual performed the testing protocol
twice, receiving either the treatment or placebo. The treadmill protocol consisted
of a five minute warm-up (3 minutes at 40% of their VO2max and 2 minutes at 55%
of their VO2max), running to exhaustion at 70% of VO2max, and a 10 minute cool
down at 3.0 mph. Every five minutes on the treadmill, variables were assessed.
RESULTS: RPE and run time to exhaustion at 70% of maximal VO2 are summarized
in this study. No significant differences were observed between conditions for run
time to exhaustion or RPE. CONCLUSION: These findings suggest that rehydrating
with a beverage containing 1,780 mg of sodium and 2,953 mg of sodium citrate
does not increase subsequent run time to exhaustion or lower RPE in previously
hypohydrated individuals during aerobic exercise at 70% of VO2max. PRACTICAL
APPLICATION: Dehydration is a major concern for athletes, especially those who
are performing in hot, humid environments. Sodium containing drinks may lead to
quicker rehydration due to greater thirst mechanism stimulation.
Poster: 3
EFFECT OF AN ACUTE INTAKE OF VESPA AMINO ACID MIXTURE ON
PHYSIOLOGIC RESPONSES DURING CYCLE ERGOMETER EXERCISE
G. Ehlers1, K. Eiting1, A. Isaackson1, D. Fecht1, C. Haynes1, A. Pawlak1, B. Pape1,
A. Reimer1, C. Strosina1, J. Yaggie1, R. Zaporski1, R. Nelson1
1
Concordia University Wisconsin
The ingestion of amino acid supplements to improve performance is not a new
phenomenon. An amino acid mixture (VAAM) based upon the composition of
Asian Giant Hornet (Vespa mandarinia) larva saliva is currently being marketed
as an ergogenic aid with claims of enhancing fatty acid utilization, reducing
blood lactate accumulation and increasing time to fatigue during cardiovascular
endurance exercise. VAAM is a blend of 17 amino acids and is sold as a powder
that can be mixed in water or sports drinks. Most research has not supported
the use of amino acid supplementation as a means of enhancing endurance
performance, making the potential of the proprietary blend of VAAM interesting
but needing more conclusive research. PURPOSE: The purpose of this study was
to examine the effect of an acute intake of VAAM on 30 minutes of submaximal
cycle ergometer exercise at an intensity just under the ventilatory threshold (VT). METHODS: A double-blinded, randomized, placebo controlled, counterbalanced
design was used. The placebo was similar to the VAAM in color, smell, taste,
consistency and caloric quantity. Both placebo and VAAM were mixed in 8
ounces of water. Sixteen physically active college-age individuals (5 female, 11
male, mean age = 21.06 ± 1.34 years) volunteered. All participants completed 4
cycle ergometer exercise sessions including a maximal exercise test (to determine
ventilatory threshold and submaximal workload), a familiarization session (to
allow adaptation to equipment and submaximal workload), and two 30 minute
cycling sessions (one taking a placebo and one taking a VAAM supplement). RESULTS: Two way repeated measures ANOVA revealed no significant differences
when comparing the VAAM and placebo groups on the following physiological
variables: VO2 (33.34 ± 4.18 vs. 33.57 ± 4.23 ml.kg-1.min-1, p = 0.238), respiratory
exchange ratio (0.95 ± 0.04 vs. 0.94 ± 0.05, p = 0.737), blood lactate (3.37 ± 2.29
vs. 3.57 ± 2.3 mmol.L-1, p = 0.725), exercise heart rate (164.5 vs. 163.7 beats.min-1, p =
0.444) and total caloric expenditure (255.60 ± 111.15 vs. 255.77 ± 111.72 kilocalories,
p = 0.918). Wilcoxon Sign Ranks Tests revealed no significant differences in
median Borg Scale ratings of perceived exertion at 10 minutes (12.5 vs. 13, p =
0.124), 20 minutes (15 vs. 15, p = 0.174) and 30 minutes (15.5 vs. 15.5, p = 0.942)
of exercise. CONCLUSIONS: An acute, single dose of VAAM did not significantly
affect physiological responses during cycling exercise performance at intensities
just below the VT. PRACTICAL APPLICATIONS: An acute dose of this VAAM
supplement was not shown to be an effective ergogenic aid for the enhancement
of submaximal performance during 30 minutes of cycling. Whether an increase
in dosage based on body weight or a loading regimen over several weeks would
change the results of this study remains to be evaluated. Time to fatigue was
not evaluated in this study and is another potential question to evaluate. Cyclists
interested in a product that will assist with cardiovascular endurance performance
should consider studies such as this one prior to making ergogenic aid decisions.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 4
EFFECTS OF HIGH-INTENSITY INTERVAL TRAINING AND B-ALANINE
SUPPLEMENTATION ON THE ELECTROMYOGRAPHIC FATIGUE THRESHOLD
A. Herda1, A. E. Smith-Ryan2, K. L. Kendall3, T. J. Herda4,
J. Stout5, J. T. Cramer6
1
University of Kansas Medical Center, 2University of North Carolina Chapel
Hill, 3Georgia Southern University, 4University of Kansas / Biomechanics
Laboratory, Lawrence, KS, 5University of Central Florida,
6
University of Nebraska-Lincoln
B-Alanine (BA) supplementation has been reported to improve intramuscular
buffering capacity during high intensity exercise. In conjunction with highintensity interval training (HIIT), BA could theoretically prolong the duration of
exercise or reduce the relative intensity of the activity. Purpose: The purpose
of the present study was to determine the effect of HIIT with or without BA
supplementation on the Electromyographic fatigue threshold (EMGFT) in
healthy college-aged women. Methods: Forty-four healthy women [mean±SD;
age (yrs): 21.8±3.7; height (cm): 166.5±6.6; body mass (kg): 65.9±10.8] were
randomly assigned to one of three treatment groups: BA (n=14), placebo (PL,
n=19), or control (CON, n=11). The BA and PL groups performed HIIT on the cycle
ergometer three times per week for a total of six weeks. EMGFT was assessed at
baseline (pre), after 3 weeks of training (mid), and after 6 weeks of HIIT (post). For
the EMGFT assessment, each participant performed a discontinuous incremental
cycle ergometer test to determine their EMGFT. Four, two-minute work bouts
(ranging from 75-250 W) were completed starting at each participant’s power
output at VT and increasing 25 W each consecutive work bout. A bipolar surface
electrode arrangement, placed over the right vastus lateralis was used to record
EMG amplitude, averaged over 10 s epochs during each cycling bout. The four
power outputs were plotted as a function of four EMG slope coefficients, with the
y-intercept defined as the EMGFT. A two-way mixed factorial ANOVA [time (pre
vs. mid vs. post) x treatment (BA vs. PL vs. CON)] was used to analyze EMGFT.
Results: The results of the ANOVA indicated there was no significant interaction
(p=0.31), main effect for time (p=0.40), nor was there a main effect for treatment
group (p=0.79). Conclusions: The present study indicated no changes in EMGFT
regardless of training or supplementation status. The lack of change could be
attributed to the lower relative intensities used during the EMGFT in the groups
that completed HIIT, where the workload during an exercise bout was not great
enough to elicit a positive slope across the four, two minute bouts. Practical
Applications: Although HIIT has been reported to improve cardiovascular fitness
in a time-efficient manner comparable to traditional endurance training, it may
not be effective in improving the onset of the EMGFT. ACKNOWLEDGEMENTS:
This investigation was supported by FSI Nutrition, Inc. Omaha, Nebraska.
Poster: 5
EVENING PROTEIN CONSUMPTION AND EXERCISE: HEALTH AND
PERFORMANCE OUTCOMES
M. J. Ormsbee1, A. W. Kinsey1, W. R. Eddy1, T. A. Madzima1,
L. B. Panton1, J. Kim1
1
Florida State University
Common perception is to limit caloric intake in close proximity to nocturnal sleep as
it may promote adverse effects on cardiometabolic health and body composition.
However, a paucity of data exist that investigate nighttime macronutrient intake
and health and performance outcomes. PURPOSE: To compare the effects of
carbohydrate (PLA), whey protein (WP), or casein protein (CP) when consumed
prior to nocturnal sleep and combined with exercise training on metabolism, body
composition, cardiovascular health, appetite, and strength. METHODS: Fortyseven sedentary, overweight and obese adults (BMI ≥25 kg/m2) participated in
this double blind, placebo-controlled study. Participants were stratified by gender
and % body fat into one of three groups: PLA (n=14; men, 4; age, 28.1 ± 7.9 yrs,
mean ± SD), WP (n=16; men, 3; age, 30.3 ± 6.2 yrs), CP (n=17; men, 3; age, 30.1
± 6.4 yrs). For four weeks, participants consumed their respective supplements
(PLA, 150 kcals/serving; WP, 150 kcals/serving; CP, 140 kcals/serving) as the last
caloric beverage at least two hours after dinner and no more than 30 minutes prior
to sleep. Participants also completed supervised exercise (3x/week; two days of
resistance exercise and one day of high-intensity cardiovascular exercise). Pre and
post training measurements of anthropometrics, body composition (dual energy
X-ray absorptiometry), resting metabolic rate (indirect calorimetry), appetite
(visual analogue scales for hunger, desire to eat, and satiety), fasting lipids and
glucose (Cholestech LDX), hormonal responses (leptin, C-reactive protein, insulin,
insulin-like growth factor-1, cortisol, adiponectin), and one-repetition maximum
(1-RM) strength for upper and lower body were completed. A one-way ANOVA
was performed to examine group differences at baseline. A 3 X 2 repeated
measures ANOVA was used to evaluate changes in dependent variables. When
appropriate, Tukey’s post hoc comparisons were performed to locate differences.
Values are means ± SE. RESULTS: No group differences in age, height, weight,
and % body fat were present at baseline or after the intervention. Significant time
effects indicating decreased body fat (baseline, 44.7 ± 0.1 %; post, 44.5 ± 0.1 %),
increased lean body mass (baseline, 52.0 ± 0.1 kg ; post, 56.2 ± 0.1 kg), increase
in 1-RM (baseline, 111.4 ± 1.6 kg; post, 127.6 ± 1.7 kg), increased satiety (baseline, 31.5 ± 2.3; post, 38.6 ± 2.54) and decreased adiponectin concentrations (baseline,
6126.8 ± 162.2 ng/mL; post, 5610.2 ± 162.2 ng/mL) were measured. No changes
were observed in any other blood variables regardless of group. CONCLUSION:
Exercise training for four weeks increases lean body mass, strength, and satiety
in sedentary, overweight and obese individuals. More importantly, macronutrient
choice and caloric intake (~150 kcals) in close proximity to nocturnal sleep over
four weeks does not negatively impact body weight and body composition,
despite common perception, when coupled with an exercise regimen. PRACTICAL
APPLICATION: Trainers and coaches may be able to advocate small single
macronutrient meals prior to sleep in overweight and obese clients, however,
much more research is needed to elucidate all possible benefits to nighttime
eating and in different populations. ACKNOWLEDGEMENTS: Our participants,
Gold’s Gym®, Jim Burtoft and Zack Muller. This study was supported by the FSU
CRC grant and the NSCA Young Investigator Award to MJO. Poster: 6
EFFECTS OF A PERSONAL OXYGEN SUPPLEMENT ON PERFORMANCE
DURING REPEAT WINGATE ASSESSMENTS
M. Sartori1, D. Bellar1, L. Judge2
1
University of Louisiana at Lafayette, 2Ball State University, Muncie, IN
In many sports the ability to intermittently work at high intensities without
degradation in performance is important for success. It is therefore important to
study supplements that might benefit repeated high intensity activity. PURPOSE:
Peak and mean power from the Wingate test were compared to determine if a
personal oxygen supplement can enhance performance during repeat Wingate
tests. METHODS: Ten college aged students participated in this investigation
(n=10). Two Wingate tests separated by thirty seconds were performed twice in a
counterbalanced fashion. Half of the participants received the oxygen treatment
during the first Wingate test, and the other half received the oxygen treatment
during the second Wingate test. Adequate recovery time was provided between
bouts of repeated Wingates. Participants who performed the Wingate with the
supplemental canister of Oxygen (95% Oxygen, 4L) were dosed liberally between
Wingates. The participants in the control group remained seated on the cycle until
the thirty seconds had elapsed. RESULTS: Analysis of the mean power produced
during Wingate testing resulted in significant main effects for treatment (F=6.283,
p2=0.411, p=0.033). The peak power generated during the Wingate testing did not
result in a main effect for treatment (F=2.34, p2=0.207, p=0.160). No significant
interaction effects for treatment*time were found for either mean or peak power
(p>0.05). CONCLUSION: The control treatment resulted in a higher mean relative
power (4.6 watts/kilogram) than the supplemental oxygen condition (4.4 watts/
kilogram). This suggests that personal oxygen supplementation is not effective
during repeat Wingate tests as an ergogenic aid, and may be detrimental to
performance. PRACTICAL APPLICATION: Strength and conditioning professionals
are interested in methods to assist athletes in recovering faster, however; it
appears that personal supplemental oxygen is not an effective treatment for
enhancing recovery between periodic high intensity activity and may reduce
performance. ACKNOWLEDGEMENTS: The authors would like to acknowledge the
contribution of Second Wind LLC to this project. Poster: 7
EFFECTS OF CAFFEINE ON THE RELIABILITY OF EMG AMPLITUDE AND
FREQUENCY FOR THE BICEPS BRACHII
M. Trevino1, J. W. Coburn2, L. E. Brown2, D. A. Judelson2, M. H. Malek3
1
Exercise Physiology Lab, California State University, Fullerton, CA, 2Center for
Sport Performance, California State University, Fullerton, CA,
3
Wayne State University
Purpose: The purpose of this study was to determine the influence of caffeine on
the reliability of electromyographic (EMG) amplitude and frequency of the biceps
brachii. Methods: Fourteen men (22 ± 2 y, 173 ± 7 cm, 85 ± 12 kg) came to the
laboratory four times. Visit one served as a familiarization visit. During visits two,
three, and four, subjects ingested their assigned drink (0, 5, or 10 mg of caffeine per
kg of body mass in a randomized, repeated measures design), rested for 60 min,
and performed three maximal isometric muscle actions of the elbow flexors for
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
the determination of EMG amplitude and frequency. Results: The results indicated
high intraclass reliability coefficients for each of the three EMG amplitudes (R =
0.936, 0.965, and 0.961) and EMG frequency conditions (R = 0.917, 0.888, and
0.839) for the 0, 5, and 10 mg∙kgˉ1 of body mass caffeine conditions, respectively.
Conclusion: It’s concluded that EMG amplitude and frequency may be reliably
determined from the biceps brachii following ingestion of either 0, 5, or 10 mg.kgˉ1
of body mass of caffeine. Practical Application: Researchers and practitioners
interested in measuring neuromuscular responses to caffeine can do so reliably
using EMG.
Poster: 8
BINGE DRINKING FOLLOWING HEAVY ECCENTRIC RESISTANCE EXERCISE:
EFFECT ON MUSCLE POWER
J. L. Vingren1, N. Idemudia1, C. Cregar1, A. A. Duplanty1,
R. G. Budnar1, D. W. Hill1
1
Poster: 10
SELECTING A RESISTANCE ASSESSMENT METHOD AND AN OPTIMAL LOAD
USING REGRESSION MODELS
J. Anning1, C. Lefever1, B. Jensen1
University of North Texas
1
Purpose: To investigate the effect of alcohol on explosive performance measures
during recovery from heavy eccentric resistance exercise. Methods: Ten healthy
men (Mean ± SD: 24 ± 2 years, 180 ± 6 cm, 86 ± 13 kg) completed 3 identical
acute heavy resistance exercise tests (AHRET) separated by 1 week. The AHRET
consisted of 4 sets of 10 repetitions of eccentric smith machine squats at 110% of
1-repetition maximum (1-RM) with 4 min of rest between sets. The first AHRET
session was used as preconditioning and no performance measures were obtained.
The second and third AHRET sessions were used for the experimental protocol.
On these 2 visits participants consumed a drink containing either alcohol (EtOH;
1.086 g of alcohol per kg lean mass; 82-122 ml total) or Placebo (no alcoho) from
10-30 minutes post-AHRET. The participants were blinded to conditions and the
order of conditions was counter-balanced. Blood alcohol concentration (BAC) was
measured using a breathalyzer. Before the AHRET (PRE), and 24 and 48 hours post
AHRET, participants performed 3 consecutive vertical jumps on a forceplate, 20
yard shuttle runs, and 20 yard sprints, all at maximal effort. Muscle soreness was
measured using analog scales at PRE and 24 and 48 hours. Results: BAC peaked
60-90 min post-exercise in all participants (0.11 ± 0.02 g·dl-1) on alcohol ingestion
days. No effect (p>0.05) of alcohol was found for vertical jump peak power (EtOH,
PRE: 55 ± 11 W·kg-1, 24h: 51 ± 6 W·kg-1, 48h: 51 ± 7 W·kg-1; Placebo, PRE: 49 ± 15
W·kg-1, 24h: 51 ± 6 W·kg-1, 48h: 53 ± 6 W·kg-1), vertical jump height, shuttle run
time or 20 yard sprint time. Leg soreness increased moderately from PRE (EtOH:
0.7 ± 0.9; Placebo: 1.0 ± 1.2) to 24 hours (EtOH: 2.4 ± 0.7; Placebo: 2.1 ± 0.6) with
no difference between conditions. Conclusion: A moderate-high BAC does not
appear to affect explosive lower body power capability 24 and 48 hours following
a heavy eccentric squat session that induces moderate muscle damage. Practical
Application: Moderate alcohol consumption post exercise may not influence lower
body soreness or power performance in the short term recovery period.
Poster: 9
SUPPLEMENTAL CITRULLINE MALATE ENHANCES RESISTANCE TRAINING
PERFORMANCE IN TRAINED MALES
B. Wax1, K. Luckett1, J. Miller1, A. Thigpen1, H. E. Webb1,
A. N. Kavazis1, J. Townsend1
1
revealed only a main effect for time with RPE increasing equally across time in
both conditions. Further, a significant interaction effect was revealed for systolic
blood pressure, a significant condition effect for diastolic blood pressure, and
a significant time effect for HR. Post-hoc analysis revealed that SBP responses
were more elevated in the placebo condition during recovery. CONCLUSION:
Collectively, these novel findings suggest that CM increases muscular endurance
during upper body resistance exercise. PRACTICAL IMPLICATIONS: Our data
suggest that acute CM ingestion prior to resistance exercise may provide an
ergogenic effect by increasing muscular endurance and mitigating demands on
the cardiovascular system, yet further research is warranted.
PURPOSE: The purpose of this study was to develop an objective approach for
professionals to select the most appropriate resistance assessment method
along with an optimal training load based on resistance training backgrounds.
METHODS: Following IRB guidelines, seventy college resistance training students
(19 men and 51 women; 20 untrained, inexperienced group; 29 untrained,
experienced group; 21 trained, experienced group) completed the flat bench
press using three resistance assessment methods: (a) Body Weight (Baechle and
Groves, Weight Training: Steps to Success, 2nd Edition), (b) 10RM, and (c) 1RM.
Students also completed questionnaires seeking their descriptive and resistance
training background information. Stepwise regression analyses used sex, body
weight [BW], and resistance training characteristics (status [TS], frequency
[TF], intensity [TI], experience [TE], bench press experience [BPE]) to develop
models for resistance assessment method selection and optimal load predictions.
RESULTS: The stepwise regression analysis developed the following resistance
assessment method selection model (scale of 1-3): -.426 + .49 (Sex) - .072 (TS) +
.185 (TI) + .534 (TE) + .993 (BPE) - .002 (BW) (r2 = 0.941). The models to predict
optimal loads in pounds for each assessment method included the following:
(a) Body Weight Method = 158.156 – 77.889 (Sex) + 6.925 (TS) + 8.933 (TE) +
.214 (BW) (r2 = 0.891), (b) 10RM Method = 162.521 – 103.319 (Sex) + .355 (BW) +
10.426 (TS) + 17.597 (TF) + 17.188 (BPE) – 10.436 (TI) (r2 = 0.92), (c) 1RM Method
= 173.107 – 103.357 (Sex) + .493 (BW) + 11.207 (TS) + 15.954 (TF) – 10.500 (TI) (r2
= 0.905). CONCLUSION: These stepwise regression models appear to be useful
in identifying the appropriate resistance assessment method prior to estimating
an optimal load based on resistance training status and experience. PRACTICAL
APPLICATION: Referring to the important variables identified through stepwise
regression analyses, professionals will know what questions are necessary to
determine resistance training status and experience. This information can then be
used to select an appropriate assessment method and load prior to designing a
resistance training program.
Poster: 12
COMPARISON OF ONE REPETITION MAXIMUM BACK SQUAT UNDER
BAREFOOT AND SHOD CONDITIONS
B. Busketta1, E. Bayer1
Mississippi State University
Ergogenics intended to improve muscular endurance and performance have
been utilized as early as 500-400 B.C. In this regard, an amino acid combination
consisting of L-citrulline and malate are being promoted as providing an ergogenic
effect on muscular endurance during athletic performances. PURPOSE: The aim
of the study was to investigate the ergogenic properties of citrulline malate (CM)
during a resistance training protocol. Based on CM chemical composition and
prior study, we hypothesized that CM supplementation will improve muscular
endurance. METHODS: To test our hypotheses, fifteen trained males (age =
23.73 ± 2.28 yr, mass = 86.91 ± 9.37 kg, height = 178 ± 6.73 cm) participated in
a randomized, counterbalanced, double blind study. Subjects were randomly
assigned to placebo CM (8.0g) or (PL) and performed three sets of chin-ups,
reverse chin-ups, and push-ups to failure. One week later, participants ingested
the other supplement (CM or PL) and performed the identical exercise protocol.
Blood lactic acid and heart rate were determined pre- and immediately postexercise. RESULTS: CM supplementation increased repetitions in chin-ups (CM =
32.93 ± 6.04; PL = 29.26 ± 7.65, p < 0.05), reverse chin-ups (CM = 32.8 ± 7.40;
PL = 26.93 ± 5.56, p < 0.05), push-ups (CM = 100.73 ± 36.73; PL = 91.2 ± 36.98,
p < 0.05), and total trial repetitions (CM = 166.46 ± 43.99; PL = 147.4 ± 47.67, p <
0.05). Blood lactate was significantly increased (p < 0.05) post-exercise compare
to pre-exercise, but were not significantly different between CM and placebo.
Self-report measures of RPE did not reveal any significant interaction effects, and
Slippery Rock University
1
Manhattan College
Debate exists over the merit of barefoot training in general; even less clear are the
potential advantages of barefoot resistance training. PURPOSE: The purpose of
this investigation was, therefore, to compare one repetition maximum 1RM back
squat strength under barefoot and shod conditions. METHODS: Subjects included
16 Division I athletes (8 male, 8 female, 20+1.2 yrs). None of the subjects had
significant barefoot training experience. Over the same two-week period, each
reported to the weight room on two separate occasions for two counterbalanced
1RM back squat assessments. On one occasion, subjects were tested barefoot B;
on the other, each wore standard running shoes S (sequence counterbalanced). An identical warm-up and 1RM assessment protocol were used throughout all
testing. A paired samples t test (SPSS software) was used to compare 1RM means
across conditions. RESULTS: No significant differences in 1RM were revealed (B
233.1+75.2, S 235.6+79.4, p>.05). No adverse events were reported. CONCLUSION: It can be concluded that, in college age subjects, naïve to B training, no advantage
in terms of force production through the lower body can be discerned. Future
research will be required to evaluate other potential benefits/risks (proprioception,
kinematics, injury risk). PRACTICAL APPLICATION: Strength coaches, personal
trainers, athletic trainers and physical therapists are advised that no clear benefit,
in terms of lower body force production, seems to be derived from B training. As
no deleterious effects were noted here, the judgment of the professional may
determine the appropriateness of B training in a given setting. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 13
THE ACUTE EFFECTS OF CONCURRENT TRAINING ON PERCEIVED EXERTION
AND STRESS DURING STRENGTH TRAINING SESSIONS
G. Deakin1, K. Doma2
Institute of Sport and Exercise Science, James Cook University, Cairns,
Australia. 2Institute of Sport and Exercise Science, James Cook University,
Cairns, Australia.
1
PURPOSE: Concurrent training has been shown to impair strength training
adaptation. The “acute hypothesis” contends that residual fatigue generated
from previous endurance training sessions may impair muscular contractility
during subsequent strength training sessions. Whilst studies have examined this
acute effect on individual strength training sessions on the same or following
day, there have been limited investigations of the quality of multiple strength
training sessions during a typical concurrent training week. METHODS: Sixteen
male and eight female moderately trained runners who were familiarized with
strength training were evenly separated into concurrent training (CON) and
strength training (ST) groups. The CON group undertook six running sessions on
consecutive days and three strength training sessions on alternating days (St1,
St2 and St3, respectively). On days when strength training and running sessions
were combined, a nine hour recovery period was provided. For the ST group, the
participants undertook strength training sessions on alternating days only. The
running sessions consisted of three incremental stages (i.e. 70-, 90- and 110%
of their ventilatory threshold) on the treadmill with two minutes of recovery inbetween each stage. The first stages were 10 minutes in duration whilst the third
consisted of three intervals (i.e. 1:1 work to rest ratio) followed by a run to exhaustion.
The strength training session consisted of incline leg press, leg extension and leg
curls with each exercise performed at six repetition maximum. There were three
minutes rest in-between each set and exercise. Rating of muscle soreness (RMS)
and muscle fatigue (RMF) were measured prior to each strength training session.
Rating of perceived exertion (RPE) was measured at the completion of each of the
first three sets during the incline leg press exercise then reported as an average
value. Blood lactate was collected immediately following each strength training
session. A two-way (group x session) repeated measures ANOVA was used to
examine differences. RESULTS: A group x session interaction effect was found for
RMS and RMF (P < 0.05) and a main effect for session found for blood lactate and
RPE (P < 0.05). Specifically, RMS and RMF were significantly greater for the CON
than the ST group and that these parameters during St2 and St3 were significantly
greater than St1 for the CON group (P < 0.05). For the CON group, RPE and blood
lactate were significantly greater during St2 and St3 than St1 (P < 0.05). However,
blood lactate was significantly less during St2 and St3 compared to St1 for the ST
group (P < 0.05). CONCLUSION: Concurrent training increases the physiological
stress and perception of effort in subsequent strength training sessions despite a
nine hour recovery period, a scenario that is not found when performing strength
training sessions alone. PRACTICAL APPLICATIONS: Due to the accumulative
effects of fatigue with moderate to high intensity concurrent training sessions,
strength and endurance training sessions with similar intensity and volume to the
current study should be performed on alternating days to allow sufficient recovery
and optimize the quality of each training session. In addition, ratings of perceived
exertion, soreness and fatigue can be used to monitor the level of recovery during
a concurrent training program.
Poster: 14
ASSESSEMENT OF BODY COMPOSITION AND PERFORMANCE
MEASURES DURING A COMPETITIVE VOLLEYBALL SEASON
IN COLLEGIATE FEMALE ATHLETES
S. Hayward1, J. Outlaw1, J. Holt1, K. Ralph1, B. Burks2, S. W. Urbina2,
C. Wilborn2, L. W. Taylor2
1
Univ of Mary Hardin-Baylor, 2Univ of Mary Hardin-Baylor/
Human Performance Laboratory
PURPOSE: Throughout the course of an athletic competitive season, an athlete
pushes their body to perform at their peak. The general goal of in-season
conditioning is to maintain as much lean muscle mass as possible thus preserving
the performance associated with the lean mass. Thus the purpose of this study
was to observe the physiological changes that occur over the course of a season
utilizing collegiate female anaerobic athletes to assess if their current in-season
training is maintaining performance and body composition. METHODS: Ten
Division III female volleyball players (18.8 ± 1.03 yrs, 65.36 ± 11.6 kg, 170.4 ± 8.6
cm, 21.39 ± 5.1 %BF) participated in a pre-season and post-season assessments. Subjects were tested prior to the season (PRE) consisting of DEXA, a standing
vertical jump (VJ), and a 3-step approach VJ (3-SVJ) to mimic an approach for
hitting during competition. In-season training consisted of resistance training (2
days/week) and sport-specific workouts, practices, and competitions designed by
the coaching staff. Subjects repeated all testing at the completion of the season
(POST). Statistical analyses utilized a paired t-test to compare all dependent
variables from PRE to POST (p<0.05). RESULTS: A significant decrease from PRE
to POST (p = 0.03) was observed for change in lean body mass (PRE: 45.01 ± 7.0
kg vs. POST: 44.13 ± 6.47 kg) which contributed to the observed significant (p =
0.03) increase in body composition (%BF). POST body composition measured
as percent body fat via DEXA increased to 22.33 ± 4.74 from PRE 21.39 ± 5.11. A
slight statistical trend (p = 0.08) was observed for increases in fat mass (PRE: 13.11
± 5.3 kg vs. POST: 13.56 ± 5.24 kg) over the course of the season. No significant
differences were observed for the dependent variables body mass (PRE: 65.4
± 11.6 kg vs. POST: 65.3 ± 11.4 kg), VJ (PRE: 21.45 ± 1.83 inches vs. POST: 21.94
± 1.45 inches), or 3-SVJ (PRE: 23.1 ± 2.28 inches vs. POST: 23.39 ± 1.96 inches). CONCLUSION: The primary findings of this study suggest despite the high volume
of activity and training that is present during a competitive collegiate volleyball
season, significant decrements in body composition are observed as indicated by
increases in %BF and decreases in lean muscle mass with no change in body mass. With no observed decreases in both VJ and 3-SVJ, it could be suggested that the
volleyball related activities and conditioning can prevent performance decrements
in lower body power. PRACTICAL APPLICATION: The results of this study can
be translated to help know that a higher intensity resistance training program
may be beneficial to implement to help negate the decrease in muscle mass over
the course of a season. Also dietary protein and nutritional considerations could
also help abate the decreases in muscle mass, although these factors were not
assessed here. The practical application is the additional knowledge for strength
and conditioning specialists when prescribing proper in-season training to
programs specific to collegiate level women’s volleyball.
Poster: 15
COMPARISON OF ON-CAMPUS AND OFF-CAMPUS SUMMER TRAINING ON
STRENGTH PERFORMANCE OF COLLEGE FOOTBALL PLAYERS
M. Heinecke1, J. L. Mayhew2
1
Winston-Salem State University, 2Truman State University
Anecdotal evidence suggest that football players have better results in their
summer training if they remain on-campus under the supervision of a strength
and conditioning specialist in preparation for the fall season. The supposition
is that those who are not under the guidance of a strength and conditioning
specialist may not reach the same intensity in their training and thus will not
achieve the same strength gains as those who stay on-campus. PURPOSE: To
assess the changes in 1RM strength performance during summer training in
college football players for those who remain on-campus and those who do not. METHODS: 88 NCAA Division II college football players (height = 185.0 ± 7.4
cm, weight = 102.2 ± 22.8 kg) self-selected into groups that stayed on-campus
for 90% of the summer (ES, n = 16), 50% of the summer (PS, n = 25), and 0%
of the summer (NS, n = 47). 1RMs for bench press and squat were performed
at the beginning of summer and again prior to Fall training camp. Each player
performed individually prescribed resistance training programs thorough out
the summer based on pre-summer maximal strength measurements. RESULTS: Height (p = 0.43) and weight (p = 0.89) were not significantly different among
the 3 groups. Although initial BP was not significantly different among the 3
groups (p = 0.25), SQ was significantly higher (p<0.01) in ES (228.6 ± 53.5 kg)
than in PS (189.6 ± 22.1 kg) and NS (181.9 ± 29.0 kg). Due to the differences at
pre-training, ANCOVA was used to determine differences in BP and SQ values,
holding pre-training scores constant. The ES (BP = 9.9 ± 6.0 kg, SQ = 29.7 ± 18.2
kg) and PS group (BP = 8.2 ± 5.9 kg, SQ = 23.3 ± 15.7 kg) made significantly greater
improvements (p<0.001) than the NS group (BP = 1.6 ± 6.0 kg, SQ = 4.3 ± 15.8 kg). Two-way ANOVA indicated that the ES group and PS group made significantly
greater percent improvement in SQ (15.7 ± 8.0% and 11.9 ± 7.7%, respectively)
than in BP (6.9 ± 4.3% and 6.2 ± 4.1%, respectively). Both ES and PS groups made
significantly greater percent improvements than NS (BP = 0.8 ± 4.1% and SQ = 0.9
±7.6%). CONCLUSION: Whether it is due to a better routine of training or greater
motivation, resistance training under the supervision of a strength and conditioning
specialist on-campus, even for part of the summer, appears to have a greater
impact of strength development than when players leave campus. PRACTICAL
APPLICATION: Strength improvements made by college football players over the
summer appear to be substantially greater when part or all of the training time
is spend on-campus under the direction of a strength and conditioning specialist.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 16
USE OF A LOW INTENSITY OCCULSION SET TO ENHANCE POST ACTIVATION
POTENITION IN A STRENGTH TASK: A PILOT STUDY
G. W. Kerby1, T. J. Pujol2, A. L. Howard1
1
than male counterparts due to less body mass and specifically muscle mass. This
data suggests male ROTC cadet’s lack strength and power when compared to
athletes. PRACTICAL APPLICATIONS: Physical fitness training for Army ROTC
cadets and active duty soldiers should increase emphasis on strength training
activities similar to athlete training programs.
SEMO, 2Southeast Missouri State University
PURPOSE: Post activation potentiation has been a common means of positively
augmenting power and strength prior to athletic competition. Conditions
encountered during occluded weight lifting provide a favorable intramuscular
environment to facilitate augmentation of strength and may be able to serve as
a potentiating activity. The intent of this study is to compare the effectiveness
of a low intensity occluded set as a means of post activation potentiation to
traditional potentiation methods. METHODS: Eleven (20±1y) normal weight
(BMI: 22.68±1.5 kg∙m2) female collegiate soccer players participated in three
separate data collections: determining predicted 1RM (P1RM), traditional post
activation potentiation (TPAP), and occluded post activation potentiation
(OPAP). Traditional and occluded methods were randomized, and each subject
participated in all three data collections. Practical occlusion was chosen to
create ischemic conditions in the muscle by utilizing elastic knee wraps placed
around the proximal thigh. Subjects performed reps occluded at 30% 1RM to
volitional fatigue. Repetition maximum was then conducted 8-10 minutes post
potentiation. Traditional potentiation involved two potentiating sets at 80% 1RM
for 5 repetitions. Repetition maximum was then conducted 8-10 minutes post
potentiation. A statistical analysis was conducted using SPSS v19.0 statistical
software package. Statistical significance was set at p<0.05. RESULTS: A
repeated measures statistical analysis indicated a significant difference in mean
work performed between P1RM and TPAP (1122.27J vs. 1883.18J) (p<0.001). A
significant difference was found comparing mean work performed between P1RM
and OPAP (1122.27J vs. 1755.00J) (p<0.001). No significant difference was found
when comparing mean work performed between OPAP to TPAP. CONCLUSION:
Occluded potentiation yields similar results to traditional potentiation utilizing
only a fraction of the load and volume. PRACTICAL APPICATIONS: When
utilizing an occluded set as a means of potentiation substantially reduced loads
(20-30%) appear to be as effective in augmenting strength in subsequent tasks.
Consequently the volume and strain placed on the muscle is reduced, thereby
potentially lowering the risk of muscular strain, fatigue and injury during the
potentiating activity. This may be useful for athletes returning to competition post
injury as they can achieve their desired outcome for a strength task while reducing
the strain placed on the muscle.
Poster: 17
A COMPARISON OF STRENGTH AND POWER MEASURES BETWEEN MALE
ARMY RESERVE OFFICER TRAINING CORPS CADETS AND DIVISION
ONE MALE AND FEMALE SPORT TEAMS
K. A. Leiting1, J. Reed1
1
East Tennessee State University
PURPOSE: The purpose of this research is to identify differences and similarities
between male Army reserve officer training corps (ROTC) cadets and athletes of
various division one sports. METHODOLOGY: 98 athletes (men’s soccer, women’s
soccer, men’s tennis, women’s tennis, baseball, women’s volleyball, and men’s golf)
and 23 male cadets performed a series of static jumps (SJ) or countermovement
jumps (CMJ) unloaded, (pvc pipe) or loaded (20kg barbell) across their shoulders.
Participants also performed an isometric mid-thigh pull on a force plate to assess
maximal strength and rate of force development (RFD). A one-way ANOVA with
post-hoc Bonferroni adjustment was used to determine statistically significant
differences. RESULTS: Baseball players were statistically significantly stronger and
had a higher jump height in all conditions compared to male ROTC cadets. Men’s
soccer players were statistically significantly stronger maximally and alometrically
scaled and had a higher jump height in 0kg SJ and 20kg CMJ. Blackwelder,
(1982) suggested that an alpha greater than 0.50 indicates that two groups are
considered similar. Women’s soccer players are considered statistically similar
to male ROTC cadets in measures of alometrically scaled IPF and rate of force
development (RFD). Men’s golf players are considered statistically similar to male
ROTC cadets on all performance measures except 20kg SJ and CMJ as men’s golf
did not perform that jump condition. Women’s volleyball and men’s tennis players
are considered statically similar to male ROTC cadets on all performance measures.
DISCUSSION: Most military tasks have been identified as strength dependent and
Army training is based on “warrior tasks and battle drills” although, most ROTC
and active duty training is based on aerobic capacity and muscular endurance.
ROTC cadets and soldiers are a product of their physical fitness training. This data
suggests disconnect between Army physical fitness training and tasks soldiers are
expected to perform. It is commonly accepted that females are typically weaker
Poster: 18
EFFECTS OF DIFFERENT REST INTERVAL BETWEEN ANTAGONIST PAIRED SETS
ON REPETITION PERFOMANCE AND MUSCLE ACTIVATION
M. D. Maia1, G. A. Paz1, E. Bezerra2, R. Simão3, H. Miranda1
1
Federal University of Rio de Janeiro, School of Physical Education and Sports,
Rio de Janeiro, RJ, 2Federal University of Amazonas, School of Physical
Education, Manaus, AM., 3Federal University of Rio de Janeiro
PURPOSE: The purpose of this study was to investigate the effects of different
rest intervals between antagonists paired set training (APST) in the number of
repetitions completed and muscle activation. METHODS: Fifteen recreationally
trained men (22.5 ± 1.9 years, 174 ± 10,1 cm and 24.3 ± 2.14 kg) with previous
resistance training (RT) experience (3 ± 0.8 years) participated as subjects
in this study. In the first and second test session was applied the 10 repetition
maximum (RM) test and retest for lying leg curl (LC) and seated leg extension
(LE) resistance exercises (48h apart). In six non-consecutive days were applied
the six experimental protocols: 1) Traditional protocol (TP) - one set of repetition
to failure on LE; 2) One set of LC followed by a set of LE without rest interval
(PWR); 3) Thirty seconds rest interval between LC and LE (P.30); 4) One-minute
rest interval between paired sets (P1); 5) Three-minutes rest interval between
paired sets (P3); and 6) Five-minutes rest interval between paired sets (P5). The
number of repetitions and electromyographic (EMG) activity of vastus lateralis
(VL), vastus medialis (VM) and rectus femoris (RF) muscles were recorded during
the LE set during each protocol. The root mean square was computed during each
set and normalized through by the percentage of maximal voluntary isometric
contraction (% MVIC). The current study was carried out following the Declaration
of Helsinki and the US Department of Health and Human Services Policy for the
Protection of Human Research Subjects (US Code, Title 45, Part 46 Protection
of Human Subjects). A one-way ANOVA with repeated-measures followed by
LSD post hoc test was used to evaluate differences in repetition performance
and muscle activation (p < 0.05). RESULTS: Significant increase in repetitions
performance were observed for PWR (14 ± 1.3), P.30 (13 ± 1.2) and P1 (13 ± 1.7)
compared to TP (10 ± 0.4). The P.30, P3 (11 ± 1.6) and P5 (11 ± 2.3) also showed
significant difference for PWR. Similar results were observed between P3 and P5
compared to P.30, as well as, among P3 and P5 for P1. The RF activation showed
a significantly increasing during PWR (75.9 ± 9.8%) when compared to TP (70.1
± 10.9%), P3 (74. 2 ± 12.1%) and P5 (69.2 ± 13.9%), and also for P.30 compared to
TP, P3 and P5. No differences were observed among TP, P1, P3 and P5. Similar
results were observed for VM during PWR (90.2 ± 12.1%) compared to TP (86
± 10.1%), P.30 (82.3 ± 11.1%), P1 (84.2 ± 10.3%), P3 (81.2 ± 10.3%) and P5 (80 ±
12.1%). Additionally, no significant differences were found for VL. CONCLUSIONS:
Significantly greater muscle activation was evident for the agonist muscles (e.g.
VM and RF) following the antagonist manipulating (e.g. LC) protocol versus the
TP. The number of repetitions completed without rest interval and with 1 minute
to 30s-rest intervals during APST was significantly higher when compared to 3
and 5-minutes rest intervals. PRACTICAL APPLICATIONS: Therefore, there is
justification for practitioners to experiment shorter rest intervals between APST
which may be associated to agonist enhancement on repetition performance and
muscle activation.
Poster: 19
EFFICACY OF THE NFL-225 TEST TO TRACK CHANGES IN 1RM BENCH PRESS
FOLLOWING TRAINING IN NCAA DIVISION IA FOOTBALL PLAYERS
B. Mann1, S. Bird1, J. L. Mayhew2
1
University of Missouri, 2Truman State University
The NFL-225 test is a premier method of evaluating upper-body resistance
performance in college football players. Although debate continues centered
on whether the test is a measure of strength or muscular endurance, numerous
investigations have attested to the potential of the NFL-225 test to estimate 1RM
bench press. However, no studies have assessed the efficacy of the NFL-225
test to track changes in 1RM strength across a training program. PURPOSE: To
determine the accuracy of the NFL-225 test for determining changes in 1RM bench
press in NCAA Division IA college football players following training. METHODS: Over a 4-year period, players (n = 203) were assessed before and after a
6-week off-season short mesocycle resistance program for 1RM bench press and
repetitions completed with 102.3 kg (225 lbs). Test sessions typically occurred
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
within one week of each other. RESULTS: 1RM bench press increased from pretraining (147.5 ± 20.6 kg) to post-training (151.7 ± 22.0 kg) for the composite
sample, although there was considerable variability in the change scores ranging
from a decrease of 24 kg (-18%) to an increase of 31 kg (25%). The effect size was
considered trivial (ES = 0.20). 66% of players increased their 1RM by 5.3 ± 4.5%,
6% remained the same, and 18% decreased by 5.9 ± 4.6%. The change in strength
was not significantly related to initial 1RM (r = -0.05), initial body mass (r = -0.11),
or change in body mass (r = 0.07). In the 46 players (22%) who gained 10 kg or
more in 1RM, the improvement was also not significantly related to initial 1RM (r =
-0.19), initial body mass (r = 0.02), or change in body mass (r = 0.03). However,
in the 15 players (7%) who decreased by 10 kg or more in 1RM, the change was
significantly related to initial body mass (r = 0.57), indicating that the greater
the decrease in body mass, the greater the decreased in 1RM following training. NFL-225 repetitions increased from pre-training (14.2 ± 6.5) to post-training (15.2
± 6.7) for the composite sample, ranging from -6 to 8 repetitions. The effect size
was considered trivial (ES = 0.15). 60% of players increased NFL-225 repetitions
by 2.3 ± 1.6 repetitions, 17% remained the same, and 23% decreased by 1.9 ±
1.3 repetitions. NFL-225 prediction equations had higher correlations with 1RM
before training (ICC>0.97) than after training (ICC>0.85). CONCLUSION: Shortterm resistance training in major college football players is capable of minor
improvement in strength and muscle endurance in college football players. The
change in strength may be negatively related to the change in muscle endurance. PRACTICAL APPLICATION: Heavy resistance training may alter the association
between muscular strength and muscular endurance in college football players
and render the NFL-225 test less effective in predicting the change in 1RM bench
press strength following training. Poster: 20
INFLUENCE OF BODY BUILD AND INITIAL STRENGTH LEVEL ON STRENGTH
GAIN FOLLOWING RESISTANCE TRAINING IN COLLEGE MEN
J. L. Mayhew1, A. Smith-Ryan2, W. Kemmler3, D. Lauber3, A. Wassermann4
1
Truman State University, 2University of North Carolina, 3University of Erlangen,
Erlangen, Germany, 4University of Bayreuth, Bayreuth, Germany
Previous investigation has suggested that genetic predisposition of body
build may influence the gains in lean tissue and muscle strength resulting
from resistance training. PURPOSE: To determine the effect of body build on
the increase in upper-body strength and fat-free mass (FFM) resulting from
periodized resistance training in college men. METHODS: 207 college men were
assessed for 1RM free weight bench press and 3-site skinfold percent body fat
(%fat) prior to and following 12 weeks of periodized resistance training. Fat
mass (FM) and fat-free mass (FFM) were calculated from %fat values. Body
build distribution was divided in thirds (slender = SL, average = AV, and solid =
SO) based on the regression of FFM/Ht2 on FM/Ht2 as reported by Van Etten,
Verstappen and Westerterp (Med Sci Sports Exerc, 26:515-521, 1994). Strength
level was divided in thirds (low = LS, average = AS, and high = HS) based on
percentile distribution of 1RM bench press. RESULTS: At pre-training, body build
groups were significantly different (p<0.001) on all variables (FM, FFM, %fat, Ht,
Wt) except age (p = 0.19). SL (58.1 ± 10.8 kg) and AV groups (63.5 ± 13.8 kg) were
not significantly different in absolute strength (p=0.08), but were significantly
lower than the SO group (69.6 ± 16.4 kg). Relative strength for SL (0.93 ± 0.17
kg/kg) and AV (0.90 ± 0.18 kg/kg) were not significantly different (p=0.83), but
were significantly higher than the SO (0.79 ± 0.16 kg/kg). Strength groups were
significantly different only in body mass (p<0.002) and FFM (p<0.001). LS (51.2
± 5.1 kg) and AS groups (64.2 ± 3.5 kg) were not significantly different in absolute
strength but were significantly lower than the HS group (84.7 ± 12.7 kg). LS group
(0.77 ± 0.12 kg/kg) was significantly lower in relative strength than AS (0.86 ±
0.16 kg/kg) which was significantly lower than the HS group (1.06 ± 0.16 kg/kg). Following training, there were no significant differences among the body build
groups for the gain in absolute strengths (SL = 7.0 ± 5.6, AV = 7.6 ± 6.9, SO = 8.3
± 6.0 kg) or relative strength (SL = 0.09 ± 0.09, AV = 0.10 ± 0.09, SO = 0.09 ±
0.007 kg/kg). There was no significant difference among the strength groupsin
absolute strength gain (LS = 8.1 ± 6.6, AS = 8.1 ± 5.6, HS = 6.4 ± 6.5 kg), but the
HS group made significantly less gain in relative strength (0.06 ± 0.08 kg/kg)
compared to LS (0.11 ± 0.09 kg/kg) and AS (0.10 ± 0.08 kg/kg). CONCLUSION: Neitherbody build nor initial strength level appear to influence upper-body
strength gains resulting from a short-term periodized resistance training program
in young men. PRACTICAL APPLICATION: Although training specificity is of
known importance to sport-specific strength gains, results from the current study
suggest that all body types will respond in a similar fashion to resistance training.
Poster: 21
THE RESISTANCE CHARACTERISTICS OF SUSPENSION TRAINING SYSTEMS AT
DIFFERENT ANGLES AND DISTANCES FROM THE HANGING POINT
D. Melrose1, J. Dawes2
1
Texas A&M University-Corpus Christi, 2Texas A&M University Corpus Christi
The resistance or load utilized during resistance exercise is the cornerstone for
appropriate exercise prescription. Suspension training systems (STS) are generally
constructed out of adjustable straps hanging from a central point, a foot sling and/
or hand grip on the terminal ends. The degree of resistance encountered by users
of STS depends on the manipulation of gravitational pull. These manipulations
are achieved by modifying strap length, angles, and body positions. To date,
load characteristics of STS have not been investigated. PURPOSE: The purpose
of this project was to investigate the effect of body angle and distance from the
STS hanging point on the percentage of body mass resistance experienced by
users. METHODS: Thirty-two college-aged participants (14 females, 18 males)
were used as subjects (age 24.06 ± 6.69 yrs, HT 172.53 ± 6.36 cm, WT 79.0 ± 17.55
kg, BMI 26.59 ± 5.27 kg/m², BF% 15.09 ± 9.84). The STS was connected to an
analog dynamometer hung from a standard power rack cross-bar. A proprietary
frame was installed on the floor between the power-rack uprights. The frame was
sectioned into 30.48 cm increments to allow measurement of resistance beyond
the hanging point of the STS. A proprietary goniometer (183 cm in length) was
used to achieve specific body angles during the data collection. Testing began
with subjects placing their feet on the floor frame directly below the hanging
point of the STS. Holding onto the STS handles, the subjects were instructed to
lean back to 60° as confirmed by the goniometer aligned between the ankles
and shoulders. Resistance readings were taken from the scale dynamometer
connected to the STS. Resistance measurements were also taken at 45°, 30°,
and 15°. The subject would then move back to each 30.48 cm increment from the
hanging point and measure resistance at each angle until maximum STS lengths
had been attained. At 60°, six increment measurements were made. At 45°, five
increment measurements were made. At 30°, four increment measurements were
made, and 15° allowed only three increment measurements. RESULTS: Across
all increments, the resistance at 60° was 28.55 ± 0.85 kg (36.13 ± 1.07%) of the
subjects’ body mass. The prediction equation for this angle is: y = 0.3693x +
2.2697. At 45°, the resistance was 40.05 ± 0.51 kg (50.69 ± 1.30%) of the subjects’
body mass. The prediction equation for this angle is: y = 0.5086x + 1.9822. At 30°,
the resistance was 51.54 ± 1.46 kg (65.24 ± 1.85%) of the subjects’ body mass. The
prediction equation for this angle is: y = 0.6306x + 2.8325. At 15°, the resistance
was 59.76 ± 1.54 kg (79.68 ± 2.06%) of the subjects’ body mass. The prediction
equation for this angle is: y = 0.7154x + 4.569. Resistance measurements varied
inconsequentially (± 1.82%) between the extremes of each increment from the
hanging point of the STS. CONCLUSIONS: As the degree of angle changes from
60° to 15°, the amount of resistance (percentage of body mass) encountered
by the user is increased. Changes in distance away from the hanging point do
not affect the percentage of body mass the individual must resist. PRACTICAL
APPLICATION: With known averages of body mass resistance at different angles,
resistance can be more accurately predicted and prescribed to STS users based
on situational needs.
Poster: 22
EFFECTS OF DIFFERENT ANTAGONIST MANIPULATION PROTOCOLS ON
REPETITION PERFORMANCE AND MUSCLE ACTIVATION
G. A. Paz1, M. D. Maia1, V. Lima2, C. Oliveira1, E. Bezerra3,
R. Simao1, H. Miranda1
1
Federal University of Rio de Janeiro, School of Physical Education and
Sports, Rio de Janeiro, RJ, 2Castelo Branco University, Laboratory of Exercise
Biodynamics, Rio de Janeiro, RJ., 3Federal University of Amazonas,
School of Physical Education, Manaus, AM.
PURPOSE: To investigate the acute effects of manipulating the antagonist
musculature (pectoralis major) on subsequent maximal repetition performance
and muscle activation during a seated row (SR) exercise. METHODS: Fifteen
recreationally trained men (22.4 ± 1.1 years, 175 ± 5.5 cm and 76.6 ± 7kg) performed
four experimental protocols in a randomized crossover design: 1. Traditional
Protocol (TP) - one set to repetition failure of the SR exercise; 2. Antagonist
Stretching (AS) - one set of static stretching for the pectoralis major followed by
one set of the SR; 3. Proprioceptive Neuromuscular Facilitation for the antagonist
(PNFA) - followed by one set of the SR; and 4. Antagonist Preloading (AP) - one
set of the bench press (BP) to repetition failure followed by one set of the SR.
The maximal repetitions and the electromyographic (EMG) signal were recorded
for the latissimus dorsi (LD), biceps brachii (BB), triceps brachii lateral head (TL)
and pectoralis major (PM) during the SR exercise. The one-way Anova followed
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PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
by LSD post hoc was applied to evaluate the differences among protocols and
variables (p < 0.05). The current study was carried out following the Declaration
of Helsinki and the US Department of Health and Human Services Policy for the
Protection of Human Research Subjects (US Code, Title 45, Part 46 Protection
of Human Subjects). RESULTS: The number of maximum repetitions performed
during BP in the AP protocol was 9.9 ± 0.4 repetitions. Significant differences
in repetition performance were observed between the AP condition versus the
TP (p = 0.0001), PNFA (p = 0.0001) and AS (p = 0.045) protocols during SR
exercise. Significant differences in repetition performance were also observed
between the AS condition versus the TP (p = 0.0001) and PNFA (p = 0.0001)
protocols. No significant differences in repetition performance were observed
between the PNFA and TP protocols. During the SR exercise, LD muscle activation
was significantly higher for the AP versus the TP (p = 0.0001) and PNFA (p =
0.0001) protocols; significantly higher activation was also demonstrated for the
AS versus the TP (p = 0.036) and PNFA (p = 0.004) protocols. Similarly, BB muscle
activation was significantly higher for the AP versus the TP (p = 0.0001) and PNFA
(p = 0.0001) protocols; significantly higher activation was also found for AS versus
the TP (p = 0.001) and PNFA (p = 0.007) protocols. However, for the antagonist
musculature, no significant differences were observed in muscle activation for
PM and TL muscles between protocols during the SR exercise. CONCLUSIONS:
These results suggest that either pre-loading (AP) or pre-stretching (AS) of the
antagonist musculature might facilitate an increase in repetition performance
for the agonist musculature versus traditional resistance exercise done without
preparatory antagonist manipulation. PRACTICAL APPLICATIONS: The results of
the current study can be applied using conventional RT machines, often used for
the majority of athletes and the general population. Exercise models performed
using a reciprocal antagonist/agonist protocol, as in the current study, may also
be less time-consuming and could be useful in clinical practice as well as sports
performance training. Poster: 23
NO EFFECT OF GRADUATED COMPRESSION SLEEVES ON MUSCLE POWER
M. C. Pereira1, M. Saulo1, R. Valdinar1, M. Andre1, J. Carmo1,
L. E. Brown2, M. Bottaro1
1
University of Brasilia, 2Center for Sport Performance,
California State University, Fullerton, CA
INTRODUCTION: Investigations have demonstrated that lower-body compression
garments can enhance jump power and running economy. Thus, athletes of many
different sports wear graduated compression sleeves during games and training
to enhance performance. Recently, the use of upper-body compression garments
has become popular in sports that require muscular strength, endurance, and
power. However, studies on the effects of these compression sleeves on muscular
performance still need to be performed. PURPOSE: Thus, the aim of this study was
to investigate the effects of graduated compression sleeves on elbow flexor power.
METHODS: Twenty-two resistance trained males (age: 23.9 ±5.2 years; body mass:
79.2 ±9.9 kg; height: 176.1 ±6.3 cm) were randomly assigned to one of two groups:
1) graduated compression sleeves (CS, n= 9) or placebo sleeves (PS, n= 13). Arm
circumference was used for the correct size of graduated compression sleeve. The
placebo sleeve was visually similar to the compression sleeve but without the
capacity for compression. Subjects performed 4 sets of 10 unilateral maximal elbow
flexion concentric/eccentric reciprocal actions with their dominant arm. They were
seated in a chair with their arms draped over a “preacher curl bench.” All exercise
was performed on a Biodex System 3 isokinetic dynamometer at 120°s-1 with one
minute rest between sets. Data were sampled at 100 Hz and were analyzed via
Biodex software. Average power (W) was calculated for each set of concentric and
eccentric actions. A 2 x 4 (group x set) mixed factor repeated-measures ANOVA was used to compare groups across sets (CS vs. PS). RESULTS: There was no
significant interaction but there were significant (p<0.05) main effects for set for
both concentric and eccentric actions. For concentric actions, power significantly
decreased across sets for both PS (set 1: 54.5 ±14.6 W > set 2: 43.5 ±9.3 W > set 3:
40.9 ±11.3 W > set 4: 36.1 ±9.2 W) and CS (set 1: 51.8 ±7.9 W > set 2: 36.9 ±5.3 W >
set 3: 31.9 ±6.32 W > set 4: 29.3 ±8.7 W). Similarly, power significantly decreased
across sets for eccentric actions, PS (set 1: 92.4 ±20.2 W > set 2: 71.7 ±14.9 W > set
3: 55.6 ±13.5 W > set 4: 46.1 ±13.8 W) and CS (set 1: 97.7 ±12.4 W > set 2: 74.1 ±12.4
W > set 3: 53.9 ±9.3 W > set 4: 48.4 ±12.1 W). CONCLUSION: Our findings suggest
that the use of graduated compression sleeves during elbow flexion exercise has
no effect on muscle power output for either concentric or eccentric actions. These
results indicate that graduated compression sleeves commonly worn by athletes
and fitness enthusiasts during training and competition do not contribute to
improved muscle power of resistance trained men during elbow flexor exercise.
PRACTICAL APPLICATIONS: Although graduated compression sleeves did not
enhance power, they also did not hinder power. Therefore, coaches and athletes
may use graduated compression sleeves at their preference for others purposes.
Poster: 24
THE RELATIONSHIP BETWEEN THE NUMBER OF WEEKLY PRACTICE HOURS
AND COMPETITION PERFORMANCE OF COMPULSORY FEMALE GYMNASTS
A. R. Russell1, H. Williford1, G. Schaefer2, M. Esco1
1
Auburn University Montgomery, 2Auburn University at Montgomery
Female artistic gymnasts in the United States (levels 1 through 6) are considered
compulsory gymnasts. All gymnasts at the same compulsory level perform the
same predetermined routines. While the skills and routines for each level are clearly
outlined, there are no regulations or instructions regarding the appropriate number
of training hours per week for gymnasts at a particular level. Thus, the number of
hours gymnasts train each week is determined by individual gymnastics clubs, and
varies widely from gym to gym. PURPOSE: The purpose of this investigation was
two-fold: first, to determine if there is a correlation between number of weekly
practice hours (WPH) and all-around competition scores (AA) of compulsory
female gymnasts, and second, to determine if there was a significant difference in
WPH between gymnasts grouped by quintiles based on AA. METHODS: The 2012
State Championships all-around scores (AA) from 438 level 4 to 6 gymnasts from
four states who competed in their compulsory championships were randomly
selected for data analysis. All scores were obtained from www.mymeetscores.
com, a public website that publishes meet results from many USA Gymnastics
sanctioned events. The number of weekly practice hours (WPH) for each gymnast
was obtained from practice schedules posted on public websites of the gyms
that the gymnasts represented at their respective state championships. Pearson
product correlation was used to determine the relationship between WPH and
AA. In addition, the sample was grouped into quintiles based on competition
scores as follows: Q1 (AA = 32.0 +/- 1.2); Q2 (33.9 +/- 0.3); Q3 (35.0 +/- 0.3); Q4
(35.8 +/1 0.2); and Q5 (36.9 +/- 0.5). One-way analysis of variance with followup procedures was used to evaluate differences in WPH between the groups.
RESULTS: There was a small significant correlation between WPH and AA (r =
0.12, p < 0.05). The mean (+/- SD) WPH for each group were as follows: 8.1 +/- 2.6
(Q1); 8.5 +/- 2.7 (Q2); 9.4 +/- 3.4 (Q3); 9.5 +/- 3.4 (Q4); and 8.9 +/- 3.3 (Q5). There
was a significant main effect for WPH between the groups (p < 0.05, Cohen’s d
= 0.19). Follow up procedures showed no significant difference between Q1 and
Q3 (p < 0.05) There was no significant difference in WPH between Q3 and Q1,
and no significant difference in WPH between Q2, Q4, and Q5. WPH for Q2, Q4,
and Q5 was significantly greater than WPH for Q3 and Q1. CONCLUSIONS: This
study found a significant correlation between WPH and AA in compulsory female
gymnasts. Furthermore, there was a significant difference based on AA. Results
indicated an overall small effect size. PRACTICAL APLICATIONS: Practitioners
should be aware of the results of this study when determining weekly practice
time for compulsory female gymnasts. The association between WPH and AA is
small. Further study is needed to investigate the relationship between the number
of practice hours and performance outcomes of compulsory female gymnasts.
Poster: 25
EFFECTS OF THREE WEEK PRESEASON STRENGTH AND CONDITIONING
PROGRAM ON A PROFESIONAL SOCCER TEAM
M. Silva1, L. Arellano Acero2
1
Claremont Graduate University, 2Club America
Participation in professional soccer requires an optimal fitness level because the
physical demands of the sport. Therefore preseason conditioning programs play
an important role in the athletic success of participants. Because the nature of the
game, many professional soccer teams during preseason conditioning program put
special emphasis on cardiovascular endurance, speed, strength and power aiming
to improve athletic performance during competition. Purpose: to investigate the
effects in physical performance before and after three week preseason strength
and condition program for an under-20 professional soccer team competing in
the Mexican soccer league. Methods: a total of 18 males (mean ± SD: age 19.4 ±
0.7 years) served as subjects for this study. Participants underwent to a condition
program with major emphasis on cardiovascular endurance, speed muscular
strength, and power. The first week of the conditioning program consisted of
two practice sessions per day for six days and one day of rest, and on the second
and third week, the frequency decreased to one practice session per day and
one day of rest after six practice sessions. Before and after the conditioning
program, a battery of field tests was administered to each of the participants
to measure cardiovascular endurance, muscular strength, and power. The field
tests utilized were vertical jump (VJ), 30 meters run, 1 repetition maximum (1RM)
bench press, 1RM squat, and 1 kilometer run. The subjects participated in two days
of testing before and after preseason. On day one participants performed the
vertical jump and the 30 meters run, and on the second day IRM bench press,
1RM squat and 1 kilometer run. A paired-samples t-test was used to determine
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PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
if any significant difference (p < 0.05) existed before and after the three week
strength and conditioning program. Results: Statistical analysis showed no
significant difference (p < 0.05) in power (VJ), speed (30 meters run) and leg
strength (1RM squat). Significance differences (p < 0.05) were observed for
cardiovascular endurance (1 kilometer run) and upper body strength (1RM bench
press). Conclusions: these results show that a three week conditioning program
was effective in improving the cardiovascular endurance and upper body strength
of professional soccer players, but not effective in improving speed, leg strength
and power. Practical applications: The findings of the present study indicate that
a three week preseason conditioning program provides sufficient stimulus to
improve cardiovascular endurance and upper body strength but has no effect on
leg strength, power and speed.
Poster: 26
A COMPARISON OF RAPID FORCE PRODUCTION AND TIME-TORQUE
CHARACTERISTICS IN ADOLESCENT MALES VS YOUNG ADULT MALES
D. B. Smith1, E. C. Conchola2, B. J. Thompson1, T. Palmer1, R. Thiele1,
A. Warren1, K. Akehi1, M. Hawkey1
1
Oklahoma State University, 2Oklahoma State University,
Applied Musculoskeletal and Human Physiology Lab, Stillwater, OK
The ability to produce force or torque is related to human performance and the
ability to produce force or torque rapidly may be even more related to human
performance. Rapid force and time torque characteristics can be measured during
the completion of a maximal isometric muscle action. During the 1RM isometric
muscle action we can obtain peak torque (PT) and rate of torque development
(RTD) across specific time periods while the muscle is contracted. PURPOSE: The
purpose of this study is to compare maximal and rapid muscle force characteristics
of adolescent males vs young adult males. The study is designed to examine
the effects of maturation on strength and rapid force development. METHODS:
Twelve adolescent males (mean±SD, age=11.6+ 0.9yr; mass=52.5±18.9kg; and
height=152.3±10.2cm) and 26 young adult males (mean±SD, age=24.9±3.0yr;
mass=118.6±11.3kg; and height=178.3±7.0cm) reported to the laboratory one time
for testing. The testing session lasted approximately 45 minutes. During the
testing session the subjects completed a 5 minute warm-up on a cycle ergometer. Maximal isometric strength testing was performed on the dominant leg using
a Biodex System 4 isokinetic dynamometer. The participants were seated with
stabilizing straps placed over the trunk, hip, and thigh and the axis of rotation
of the lever arm was aligned with the axis of rotation of the knee joint. For leg
extension testing the lever arm was positioned at 60° below the horizontal plane
and for the leg flexion testing the lever arm was positioned at 30° below the
horizontal plane. Each participant performed 2-3 isometric maximal voluntary
contractions (MVCs) lasting 3-4 seconds with the leg extensors and flexors
with a one minute rest period between muscle actions and three minutes of
rest between muscle groups. Testing order was randomized to control for any
effects of fatigue. PT and RTD at specific time periods (PeakRTD, RTD30ms,
RTD50ms, and RTD100-200ms, RTD1/6MVC, RTD1/2MVC) were collected for each
subject and comparisons were made between the two groups (adolescents vs
young adults). RESULTS: A one-way ANOVA was used to compare the collected
performance variables between the two groups. For leg extension there was a
significant (p<0.05) difference between the two groups for every variable tested
with the young adults having greater PT, and higher PeakRTD, RTD30, RTD50, and
RTD100-200. When normalized to strength the two groups were also significantly
(p<0.05) different at RTD1/6MVC and RTD1/2MVC. For the leg flexors, similar
results were found across all variables except for there was no significant (p>0.05)
difference between the two groups at RTD1/2MVC. CONCLUSIONS: The ANOVA
results indicated that the young adult males appear to be able to develop force
more rapidly than adolescent males. The young adult males performed better
for all variables for the leg extenders, and all of the variables with the exception
of the relative RFD at 1/2MVC for the leg flexors. PRACTICAL APPLICATIONS:
These findings indicate that there are differences between adolescent and young
adult males in the ability to rapidly produce torque which are primarily related
to strength differences between the two groups. This appears to be related to
developmental changes in muscle size and possibly neural factors associated
with strength increases that occur with maturation which could affect functional
performance. Poster: 27
A COMPARISON OF THE MODIFIED SINGLE-LEG SQUAT AND THE BACK SQUAT
IN NCAA DIVISION I BASEBALL ATHLETES
F. Spaniol1, R. Burnett1, J. Dawes2, B. McQueen1
1
Texas A&M University-Corpus Christi, 2Texas A&M University Corpus Christi
PURPOSE: The purpose of this study was to compare the effects of performing
the Modified Single-Leg Squat (MSLS) versus the Back Squat (BS) on rotational
power, lower-body strength, and leg-power in NCAA Division I Baseball
Athletes. METHODS: Thirty-five Baseball student-athletes completed an 8-week
resistance training protocol consisting of either the MSLS or the BS. The Rotary
Power Test was used to determine rotary power (RP). Bilateral strength (BLS) was
measured using a BS 3 repetition-max (RM) test; unilateral strength (ULS) was
measured using a MSLS 3 RM test. Bilateral (BLP) and unilateral leg power (ULP)
were assessed via vertical jump testing on a HYTEK force plate. Subjects were
randomly divided into two groups, which were further sub-categorized based on
position (pitchers and position players). Both groups were required to perform
the same resistance-training program; however, one group was assigned the MSLS
as the primary lower-body strengthening exercise whereas the other group was
assigned the BS. The 8-week off-season training protocol consisted of a four-day/
week upper and lower body split-routine. Both the MSLS and BS exercises were
progressed in a linear fashion, beginning with 50% of each subject’s 1RM for 10
repetitions per set (R/S) for 4 sets in weeks 1-7, and ultimately progressing to 90%
of each subject’s 1RM for 3 (R/S) for 5 sets in week eight. Load assignments per
set and desired repetitions ranges were similar for each group. RESULTS: Paired
t-tests were used to determine statistical differences between pre and posttesting for each variable in both groups. Independent T-tests were also used to
analyze any mean differences between the groups’ post-test scores; significance
was determined at the p <.05 level. The MSLS group improved significantly from
pre-testing in RP (p = .03), ULP with the right leg (p = 0.04), ULS (p ≤ 0.01) and
BLS (p ≤ 0.01). There were no significant differences between groups on any of the
performance variables. CONCLUSIONS: These results suggest that both the MSLS
and BS exercises are effective in increasing lower-body strength. However, only
the MSLS group revealed a statistically significant difference in RP and ULP from
pre to post test. Thus, it appears the MSLS exercise may be a more appropriate
exercise for increasing baseball athletic performance. PRACTICAL APPLICATIONS:
Results indicate that both unilateral and bilateral closed-kinetic chain, lower body
strength training exercises may be viable options for increasing bilateral and
unilateral leg strength. Only the unilateral strength exercises increased rotational
power and unilateral power of the right leg in this study. The additional hip and
knee stability requirements, in addition to the strengthening of hip and knee
extensors, make the MSLS a valuable exercise for comprehensive lower-body
development.
Poster: 28
A COMPARISON OF THE EFFECTS OF PLYOMETRIC AND RESISTANCE
TRAINING ON LOWER BODY MUSCULAR PERFORMANCE IN
RECREATIONALLY TRAINED MALES
M. T. Whitehead1, T. P. Scheett2, M. R. McGuigan3, A. V. Martin4
1
Stephen F. Austin State University, 2College of Charleston,
3
Sports Performance Research Institute New Zealand,
4
Louisiana State University Shreveport
PURPOSE: The purpose of this study was to compare the effects of eight
weeks of separate plyometric and resistance training programs on lower body
muscular performance. METHODS: A convenience sample of thirty recreationally
active, apparently healthy, low-risk males aged 21.3 ± 1.8 years, height 177.3 ±
9.4 cm, mass 80.0 ± 2.6 kg, body fat 16.1 ± 1.2 % volunteered and participated
in this investigation. Participants were grouped and participated in progressive
plyometric or resistance training twice per week for eight consecutive weeks
or a control group that did not participate in any training. Performance tests
were administered prior to and following the training period and included
measures of vertical jump, one-repetition maximal back squat, 20-meter sprint,
and agility. RESULTS: Analysis of variance followed by post hoc analyses was
performed in order to determine significant differences between the groups.
Data were converted to pre-post change in order to account for initial between
group differences, and statistical significance set at p £ 0.05 for all analyses.
Significant differences between the groups following the eight-week training
period were indicated for vertical jump, and one-repetition maximal back squat
with no between group differences found for 20-meter sprint or the agility run.
Post hoc analyses indicated that the plyometric training program resulted in
greater improvement in vertical jump 17.15 ± 10.60 vs. 5.87 ± 4.82 vs. 0.71 ± 1.62
% for the plyometric, resistance training, and placebo groups, respectively. No
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PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
differences were found between the plyometric and resistance training groups
for one-repetition maximal back squat. CONCLUSIONS: These data indicate
eight weeks of either plyometric or resistance training results in improvements
in measures of lower muscular performance with no apparent impact on speed
or agility, and that plyometric training has a greater influence on vertical jump
than resistance training. PRACTICAL APPLICATIONS: In an effort to optimize
performance and maximize time spent training coaches, trainers and athletes are
continuously seeking effective training methods. Questions frequently arise as
to which training method is best for a given performance parameter. Plyometric
training programs similar in duration and intensity to the one used in the current
study should result in an improvement in vertical jumping ability. Both plyometric
and resistance training appear to result in improvements in lower body muscular
performance in untrained men. Poster: 29
USING NON-TRADITIONAL STRENGTH TRAINING TO SUPPLEMENT OFF SEASON
TRAINING IN DIVISION III COLLEGE FOOTBALL PLAYERS
G. A. Wright1, K. Schultz2, R. Monroe2, J. Dettwiler2
1
University of Wisconsin-La Crosse, 2University of Wisconsin-LaCrosse
Non-traditional strength training typically involves exercises such as heavy tractor
tire flips, pushing and pulling heavy sleds or cars, lifting sandbags, and other
heavy objects. Biomechanical analysis of many of these types of non-traditional
exercises has been performed to describe the kinematics and kinetics involved.
However, while many strength and conditioning coaches use this type of training
for their athletes, no previous study has investigated how using these types of
training tactics may affect the changes in strength, speed, and power normally
produced during an off season. PURPOSE: The purpose of this investigation
is to determine the efficacy of supplementing non-traditional (NT) strength
training with traditional (T) strength training performed by college football
players. Our intention is to determine if the use of NT training may replace one
T training sessions per week. METHODS: Forty-six Division III college football
players were recruited for the study. All subjects played at least one season and
participated in traditional strength training under the direction of the Strength
and Conditioning Staff. Subjects were assigned to a NT group (n=23) made up
of offense and defensive linemen, tight ends, linebackers or a T group (n=23)
made up of offensive (running backs, wide receivers, quarterbacks) and defensive
(defensive backs) skill positions. All subjects participated in a 12 week off-season
training program consisting of block periodization. Speed, agility, energy system
development (ESD) and strength training made up the program with 1 day per
week (d/wk) speed, 1 d/wk agility, 1 d/wk ESD and 4 d/wk strength training (2
upper, 2 lower body). The only difference between the 2 training groups was that
the NT group substituted “Strongman” type exercises for the second lower body
strength workout. Exercises used for the NT training included various sandbag
lifts, heavy sled pulls and pushes, heavy ropes, weighted carries, and flipping of
a weighted implement. These exercises were periodized similar to the rest of the
training for each block (high volume vs. high load). Pre and post testing included
football specific tests of strength, speed and power: 10 meter weighted simulated
sled drive (45 kgs) for time, standing vertical jump, push press throw peak power
(60 kg), and repeat Pro Agility test (10 x Pro Agility; 1 every 30 sec). RESULTS:
Improvement was observed in both groups for all tests. Independent t-tests
indicated there were no significant differences observed between groups between
pre and post testing (% change) for the 10 meter sled drive (T= -4.7% ±7.9%, NT=
-2.2% ± 7.7%; p=0.29), push press throw power (T= 11.0± 9.4%, NT= 11.8±12.4%;
p=0.81), Pro Agility Total Time (T=-2.3±3.5%, NT= -2.0±3.2%; p=0.84), Pro Agility
Best Time (T= -2.2± 2.9%, NT= -1.6± 3.9%; p=0.57), and vertical jump (T= 6.4±4.4%,
NT= 3.3±5.8%; p=0.11). CONCLUSIONS: The substitution of a non-traditional
strength training session at the expense of one less weight room session per week
does not decrease the amount of strength, speed, and power improvement during
an off-season football training program. PRACTICAL APPLICATIONS The results
of this study indicate that NT training does not need to be an additional training
session during a microcycle. This type of training activates most muscle groups
trained for football, therefore could replace one training session per week during
either a split routine or total body training sessions. Poster: 30
GLUCOSE AND LACTATE RESPONSES TO PEAK TREADMILL TESTING IN
PATIENTS RECOVERING FROM A TRAUMATIC BRAIN INJURY
W. E. Amonette1, P. Lea2, B. Masel3, M. Sheffield-Moore2, R. J. Urban2,
K. A. Mossberg2
University of Houston - Clear Lake, Department of Clinical, Health, and
Applied Sciences, Human Performance Laboratory, 2University of Texas
Medical Branch, 3The Transitional Learning Center
1
Patients with a traumatic brain injury (TBI) experience numerous impairments post
injury including neuroendocrine dysfunction, reduced aerobic capacity (VO2),
and early onset of anaerobic threshold (AT). Moderate duration exercise, above
AT utilizes glucose as a primary substrate for energy production; thus, glucose
utilization may be essential for patient with a TBI. PURPOSE: To compare the
serum glucose and lactate responses to graded treadmill exercise in patients with
a TBI and age-matched healthy controls. METHODS: Eight patients with a TBI
(TBI; 31.3±1.6 y, 177.8±3.6 cm, 96.1±5.5 kg) and 8 age- and gender-matched healthy
controls (CON; 30.6±2.1 y, 173.2±2.7 cm, 85.6±6.8 kg) participated. Cause of injury
in the TBI group included motor vehicle accidents (n=2), blunt head trauma (n=1),
injury from a fall (n=1), and injuries resulting from detonation of an improvised
explosive device (n=4). Participants could safely ambulate on a treadmill at 5.3
km/h and had few if any motor impairments. TBI and CON performed a single
peak exercise test on a treadmill. Subsequent to an overnight fast, a venous
catheter was inserted into the antecubital vein (0800–0830h) before one hour
of quiet sitting. The participants were connected to an automated metabolic cart
and 3-lead EKG system 10-minutes prior to exercise. Five mL of blood (BASE)
was drawn into a sterile tube immediately prior to participants performing a
single speed (5.3 km/h) modified Balke-Ware protocol that had been tested for
reliability in patients with a TBI. Patients exercised to peak, which was confirmed
by volitional failure, VO2 plateau, and RER of >1.10. Five mL of blood was drawn
post-exercise at minutes +0, +10, +20, +30, and +60. After exercise, blood was
centrifuged at 3000 RPM for serum separation and stored at -80 degrees. In
batch, serum glucose and lactate were determined using chemiluminescence. RESULTS: No significant differences in peak RER were evident between groups
(CON=1.2±0.1; TBI=1.2±0.1). Within CON, lactate was elevated compared to BASE
(p<0.05) at minutes +0 (Δ5.7 mmol/L), +10 (Δ10.1 mmol/L), +20 (Δ7.5 mmol/L ),
and +30 (Δ4.8 mmol/L ). Lactate was elevated in TBI at minutes +0 (Δ7.8 mmol/L),
+10 (Δ7.2 mmol/L), +20 (Δ5.0 mmol/L ), and +30 (Δ3.2 mmol/L). At minute +10,
lactate was greater (p=0.03) in CON (11.9 ± 1.4 mmol/L) compared to TBI (8.9±1.4
mmol/L). Within CON, serum glucose was lower than BASE at minute +0 (Δ-12.9
mg/dL), but at no other time point. Conversely, glucose was elevated in TBI at
minutes +0 (Δ12.5 mg/dL), +10 (Δ18.9 mg/dL), +20 (Δ14.4 mg/dL), and +30 (Δ11.8
mg/dL). Glucose was lower (p=0.009) in the CON compared to TBI at minutes
+0 (CON=76.7±4.8 mg/dL; TBI=98.9±7.1 mg/dL) and +10 (CON=86.5±4.1 mg/dL;
TBI=105.3±8.2 mg/dL). CONCLUSIONS: These data indicate a clear difference
in the glucose response to exercise in patients recovering from a TBI compared
to CON. Poor glucose uptake could be due to deficiencies with insulin-receptor
sensitivity, reduced insulin response, or reductions in the insulin independent
mechanisms of glucose uptake resulting from exercise. Research is needed
to determine if these differences are the result of TBI or a sedentary lifestyle
adopted post injury. PRACTICAL APPLICATIONS: Along with improving
aerobic capacity, exercise practitioners should prioritize and implement training
programs that improve glucose utilization in patients recovering from a TBI.
ACKNOWLEDGEMENTS: This work was supported, in part, by the Fannie Kempner
Adoue Endowment and NIH grant R01-HD046570 to Dr. Mossberg.
Poster: 31
THE EFFECT OF MATURATION ON STRENGTH AND DETRAINING
ADAPTATIONS IN 11 TO 15 YEAR OLDS
J. Cronin1, J. Oliver2, B. Contreras1
1
Sport and Performance Research Institute New Zealand/AUT University,
2
Cardiff Metropolitan University
Purpose: Knowledge of when to apply an optimal training stimulus during athlete
development is essential for effective programming and improving athletic
performance. Major morphological and neural changes are occurring during
growth and maturation, which could play an important role to training adaptations
and rate of decay in performance. However, the research investigating the effect
of maturity on strength training dose-response relationship and decay in athletic
performance is still lacking in youth Methods: Thirty-three males performed
an 8-week strength program twice per week followed 8-week detraining. The
maturity status of the athletes was determined using years from PHV to split
them into three maturity groups for analysis: Pre PHV (-1.7 ± 0.4 y; n=10), Mid
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PHV (-0.2 ± 0.4 y; n=11) and Post PHV (1.0 ± 0.4 y; n=12). Training consisted of
four exercises (3 x 10-12 repetitions) that aimed at developing both bilateral and
unilateral horizontal and vertical force production. Exercise progression was
based on increasing load but also movement complexity. At baseline, post training
and detraining, the participants completed a 30-m sprint, horizontal jump, and
ballistic concentric squats on a supine squat machine at five different loads
relative to body mass in a randomised order: 80%, 100%, 120%, 140% and 160%.
From the ballistic protocol, one-repetition maximum (1RM) and force-velocitypower profiles were determined using the load-velocity, force-velocity and loadpower relationships. Standardized differences within and between groups were
assessed via magnitude-based inference statistics, with clear effects defined by
acceptable 90% confidence intervals. Results: The training effect on sprint time
(-2.1% to -4.7%) and power measures (6.5 to 20%) was meaningful for all groups
but a small training effect advantage was observed for the Mid and Post PHV
groups as compared to Pre PHV. The change in 1RM (9.4%) was only meaningful
for Post PHV and differed to a small effect (6.5%) to the other two groups. The
small shift in velocity capability (2.7-16%) across the groups was greater by a
moderate effect in Pre PHV compared to Post PHV (4.4%) . The decay in 1RM and
power was trivial to moderate across the groups (-0.5% to -6.5%), the detraining
effect smaller for Mid and Post PHV compared to Pre PHV subjects. Decay in sprint
performance was only meaningful in Post PHV (0.6 to 0.9%). Conclusion: The
strength-training program was beneficial in improving vertical strength, vertical
and horizontal power, acceleration and maximal speed across different maturity
groups but the magnitude of the training and detraining effects were maturity
dependent. The maturity-specific adaptations to strength training and detraining
have important implications for optimal training emphasis periods during growth
and maturation. Practical Applications: Strength training was more beneficial at
enhancing vertical power and 10-m time in Mid and Post PHV compared to Pre
PHV. Rather than strength training, activities providing a velocity stimulus may be
more valuable for athletes prior to PHV to develop power and speed. Regardless,
practitioners should include bilateral and unilateral vertical and horizontal force
production exercises to optimally enhance all aspects of explosive performance
and maintenance programs should be planned to reduce rate of decay, especially
in Pre and Post PHV subjects. Acknowledgements: The investigators would like to
thank Will G. Hopkins for his advice on the statistical analysis of this project.
Poster: 32
METABOLIC DEMAND DURING MULTI-MODAL UPPER EXTREMITY
EXERCISE IN PEOPLE WITH SPINAL CORD INJURY
G. Duran-Monge1, B. Clift1, N. Evans1
1
Beyond Therapy, Shepherd Center
PURPOSE: Spinal cord injury (SCI) often results in immediate and permanent
disability. Individuals who suffer a SCI often become less physically active due
to reduced ambulatory capacity, decreased activation of skeletal muscle, and
limited access to adaptive exercise activities. As a result, those with SCI are more
likely to become sedentary, expend fewer daily calories, and develop secondary
health complications such as obesity, Type II diabetes, and cardiovascular disease.
In order to counteract the deleterious effects of reduced physical activity, it is
imperative that individuals with chronic SCI continue to be physically active and
exercise professionals have a full understanding of the physiologic and metabolic
demands of specific exercise activities in order to optimize training outcomes
for those with SCI. The purpose of this project was to quantify the metabolic
demands associated with three specific exercise activities performed by subjects
with SCI. METHODS: Data was obtained from five, male subjects aged 29 to 58
years with paraplegia resulting from SCI. All subjects completed three, 30 minute
exercise sessions including: (1) ropes training, (2) hand cycle ergometry, and (3)
boxing. One exercise session was completed per week to allow for adequate
recovery between sessions. Metabolic testing was performed to determine
exercise energy expenditure (EE) and relative VO2 during each session. Due to
the intense nature of the exercise, we hypothesized that 30 minutes of ropes
training would elicit the highest exercise EE and relative peak VO2 compared to
boxing and hand cycle ergometry. RESULTS: Mean EE for each 30 minute exercise
activity was 145.7±47.3 kilocalories (ropes), 139.0±26.9 kilocalories (boxing),
and 144.3±44.1 kilocalories (hand cycle ergometry). A between group analysis
revealed no significant difference (p = 0.96) in EE between exercise modalities.
In addition, there were no significant differences (p = 0.39) observed in relative
peak VO2 between exercise modalities, however, for all but one subject, the ropes
training exercise elicited the highest relative peak VO2 compared to boxing and
hand cycle ergometry. CONCLUSIONS: Based on preliminary results, it appears
that the average caloric expenditure for 30 minutes of either ropes training,
boxing, or hand cycle ergometry is relatively similar between exercises among
this small sample of subjects with SCI. Therefore, it would seem that each of
these activities would be equally valuable in facilitating a modest daily caloric
expenditure and could be used in conjunction with other exercise modalities to
promote lifelong physical health. However, the ropes training protocol in this
study may prove to have additional cardiovascular benefit above and beyond that
of boxing and hand cycle ergometry based on the intense nature of the activity
and the fact that the highest peak VO2 values among all but one subject were
observed during the ropes training sessions. Additional research with a much
larger sample size is needed to elucidate whether a real and meaningful difference
in metabolic demand truly exists between these exercise modalities. PRACTICAL
APPLICATIONS: Data obtained from this study can be used to help individuals
with disabilities and exercise professionals identify those exercises that may elicit
the greatest cardiovascular benefit and greatest overall EE to facilitate caloric
balance and reduction of secondary health complications following chronic SCI.
ACKNOWLEDGEMENTS: Thanks to the Shepherd Center and the Beyond Therapy
Department for their support and continued commitment to improve the quality
of care for individuals with disabilities.
Poster: 33
THE PREVALENCE OF LOW BACK PAIN IN THE RECREATIONAL
WEIGHT TRAINING POPULATION
W. J. Hanney1, M. J. Kolber2, P. Pabian1
1
University of Central Florida, 2Nova Southeastern University
Purpose: An estimated 45 million Americans participate in some form of weight
training (WT) on a regular basis. Data from the National Health Interview Survey
conducted by the Centers for Disease Control found that nearly 20% of adults
ages 18 to 65 participate in some form of WT two or more times a week. Although
the benefits of resistance training have been well documented, participation is
not without risk. A significant number of injuries associated with WT have been
reported in the literature with approximately 25% of those being severe enough to
seek medical attention. Previous reports indicate that WT participants sustain, on
average, 2.6 injuries per 1000 hours of activity. Low back pain (LBP) and or injury
has been reported at a rate of 0.43 per 100 hours of participation and appears to
be one of the more common sites of injury among WT participants. Previously
reported injury rates among WT participants have generally been inclusive of
a competitive population and there is little information with regards to LBP in
the recreational WT population. Therefore, the purpose of this study was to
identify the point and period prevalence rates of LBP in the recreational WT
population. Methods: Individuals between the ages 18 to 59 were recruited to
participate. Subjects participated in weight training 2 times per week for at least
1 year. Information was collected via in person surveys and included age, height,
body mass, and gender. Participants were asked if they are currently experiencing
LBP (point prevalence) or have had an episode in the past 6 months or 1 year.
Results: Point prevalence of LBP in the recreational weight training population
was approximately 10.5% while the six-month prevalence was 28% and 1-year
prevalence was 41.5%. Conclusions: Point prevalence of LBP in recreational
weight trainers in this study was lower than the general population, which has
been estimated to be as high as 28.4%. Also approximately 28% of the subjects in
our study had a 6-month period prevalence of LBP where it has been reported to
be has high as 48.9% in the general population. Finally, the one-year recurrence
rate of LBP has been reported to be as high as 80% while our study demonstrates
reports to be 41.5%. Our findings suggest that recreational WT participants
have lower reports of LBP than the general population. Practical Applications: While LBP prevalence rates have been reported to be a significant problem in
the competitive WT population the results of our study show that the point
prevalence, 6 month and 1 year period prevalence of LBP among recreational
WT is below the general population. It seems the one-year prevalence rates are
much lower than the general population. Perhaps participation in a recreational
weight-training program is protective for episodes of LBP evident by the lower
rates. Prospective based studies are needed to determine if indeed recreational
WT mitigates risk for LBP.
Poster: 34
ACCURACY OF THE BODY ADIPOSITY INDEX FOR ESTIMATING BODY FAT IN
INDIVIDUALS WITH DOWNS SYNDROME
B. Nickerson1, A. R. Russell1, S. Bicard1, A. Mahurin2, M. Esco1
1
Auburn University Montgomery, 2Baptist Family Residency Program
The Body Adiposity Index (BAI) was recently developed as a method to predict
body fat percentage (BF%) by using only the variables of hip circumference and
height. The simplistic, non-invasive nature of BAI makes it an attractive option
for estimating adiposity in individuals with Down’s syndrome (DS), who may
feel threatened by more elaborate equipment. However, the BAI was previously
validated within groups from the general population. The accuracy of the BAI for
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individuals with DS remains questionable since body fat is distributed differently
in this special population compared to individuals without DS. PURPOSE: The
purpose of this study was to cross-validate the BAI in individuals with DS using
dual-energy x-ray absorptiometry (DXA) as the criterion measure. METHODS:
Twelve adults and five adolescents with DS (n=17) participated in the study. Height was measured with a wall-mounted stadiometer and hip circumference
was measured horizontally at the maximal extension of the gluteus maximus. The
BAI method was used to predict BF% with the following equation: BAI-BF% = ([hip
circumference/height1.5] – 18). Criterion BF% was determined via DXA. RESULTS:
The mean BF% obtained from the DXA was 35.7 ± 13.4 and predicted from the BAI
was 39.4 ± 11.2 (p = 0.06, Cohen’s d = 0.30). The BAI significantly correlated with
the DXA (r = 0.83, p < 0.05) and had a standard error of estimate (SEE) of 7.8%. The
method of Bland-Altman revealed that the 95% limits of agreement ranged from
11.2% below to 18.6% above the constant error (CE) of 3.7%. CONCLUSIONS: The
findings of this study suggest that BAI overestimated BF% by 3.7% compared
to the criterion. Though the mean difference between the two BF% measures
was not quite significant, the effect size was moderate. In addition, the BAI
resulted in a high SEE of 7.8% and the limits of agreement were large. PRACTICAL
APPLICATIONS: The BAI has the potential to become widely used in clinical
and fitness settings. Practitioners who design healthy lifestyle strategies for
individuals with DS should consider the results of this investigation before using
the BAI for predicting BF%. It appears to provide overestimated values and may
result in a large range of individual error. Therefore, the BAI should be used with
extreme caution when predicting BF% in individuals with DS. Poster: 35
MEASUREMENTS OF REACTION TIME DOES NOT DIFFER BETWEEN
FUNCTIONAL FITNESS GROUPS IN OLDER ADULTS
S. Paulson1, M. Gray2
1
Shippensburg University, 2University of Arkansas
Research suggests reaction time (RT) slows as one ages. Conversely, some
individuals display a resistance to age-related declines in RT due to maintenance
of physical fitness. PURPOSE: The purpose of this study was to assess differences
in RT measurements between low and high functionally fit older adults. METHODS:
Nineteen older adults volunteered to complete a computer based RT assessment
and a power stair climb test (PSCT) to measure functional fitness. Relative power
from the PSCT was used to create the two functional fitness two groups; low (n =
8, age: 73.8±6.9 yrs; ht: 1.64±0.16 m; mass: 76.56±15.51 kg; body fat: 38.11±7.88%)
and high (n = 11, age: 70.5±5.6 yrs; ht: 1.64±0.14 m; mass: 72.72±15.15 kg; body
fat: 33.58±6.54%). All subjects passed the Mini Mental State Examination and
were free from uncontrolled cardiovascular, metabolic, and pulmonary disease.
Anthropometric measurements and a dual energy x-ray absorptiometry were
completed prior to testing. A 10-min computerized test was used to measure simple
reaction time (SRT), choice reaction time (CRT), sequential reaction time 1 (SEQ1),
and sequential reaction time 2 (SEQ2). For the PSCT, each subject was instructed
to ascend a set of nine steps as quickly and as safely as possible for three trials. The
subjects began at the bottom of the first step and a stopwatch was started on the
commend “Go”. Time ended when both of the subjects’ feet touched the landing.
The best time was used for analysis. Data were analyzed using a one-way ANOVA.
RESULTS: There was no statistically significant difference between the functional
fitness groups on SRT, CRT, SEQ1, or SEQ2 (p > .05). CONCLUSION: The results
of the study suggested there was not a difference between levels of functional
fitness on various measurements of RT in older adults. PRACTICAL APPLICATION:
Health fitness professionals working with an aging population may be working
toward the goal of improving functional fitness. While functional fitness as it is an
important aspect of quality of life of older adults, it appears not to influence RT.
Previous studies have found improvements in RT with high-velocity and functional
training programs. Thus, it is essential to recognize the influence functional fitness
training may have on measurements of RT.
Poster: 36
THE INFLUENCE OF TRANSCRANIAL DIRECT CURRENT STIMULATION ON
MAXIMAL FORCE PRODUCTION IN PARKINSONS DISEASE
B. Poston1, E. Heisler2, R. Walsh1, J. Alberts2
1
Cleveland Clinic-Las Vegas, Lou Ruvo Center for Brain Health,
2
Cleveland Clinic
Transcranial direct current stimulation (TDCS) is a non-invasive brain stimulation
method that has recently been used as a modality to acutely increase maximum
force production in healthy young adults and stroke patients. Previous studies
have also shown that TDCS may improve some aspects of motor function in
Parkinson’s disease (PD) such as the rate of motor skill acquisition and the speed
of gait. PURPOSE: To determine the influence of acute application of TDCS on
the maximum force production capacity of hand muscles in PD. METHODS: The
study was a sham-controlled, cross-over experimental design and 6 subjects
diagnosed with idiopathic PD participated in the study. Each subject completed
2 experimental sessions each separated by a washout period of 7 days. Subjects
received either real TDCS or SHAM stimulation on a given day with the order of
presentation of the conditions counterbalanced. Subjects performed 3 maximal
voluntary contractions (MVCs) in an index finger abduction task and a pinch grip
task before (Pre-tests) and after (Post-tests) application of both real TDS and
SHAM stimulation. Real TDCS was applied continuously to the area of the scalp
overlying the hand area of the contralateral motor cortex of the primarily affected
hand for 20 minutes at a current strength of 2 milliamps. SHAM stimulation
was applied in the same experimental settings for 20 minutes and conducted
according to a well-established protocol that elicits the same sensations on the
surface of the scalp as real TDCS application. Thus, subjects could not distinguish
between real TDCS and SHAM stimulation. MVC force was measured before and
after application of TDCS in both the index finger abduction and pinch grip tasks.
MVC force was quantified as the average maximum force produced during the 3
MVC trials for each task. RESULTS: The increase in MVC force between the Preand Post-tests was greater (~ 10.0%) following application of real TDCS compared
to SHAM stimulation (~ 0.3% force increase) in the index finger abduction task. In
the pinch grip task, MVC force was increased (~5.5%) between the Pre- and Posttests in the real TDCS condition, but decreased (~ 2.0%) in the SHAM condition.
CONCLUSIONS: Collectively, these findings suggest that a single application
of TDCS can acutely increase the maximum force production capacity of hand
muscles in PD. PRACTICAL APPLICATIONS: TDCS may represent a new adjunct
intervention strategy to acutely increase force production in healthy adults and
in patients with movement disorders. Furthermore, TDCS devices are relatively
inexpensive, easy to operate, portable, and extremely safe. However, further
research is needed to determine the optimal parameters of TDCS to improve
force production and to examine the extent to which chronic TDCS application
(weeks or months) may improve force production in healthy adults, well-trained
athletes, and in patients with movement disorders. ACKNOWLEDGEMENTS: The
Lincy Foundation.
Poster: 37
MICROCLIMATE UNDER SOFT BODY ARMOR DURING MODERATE
PHYSICAL EXERTION
G. A. Ryan1, R. L. Herron2, S. H. Bishop3, C. Katica2, B. Elbon4,
A. Bosak5, P. Bishop2
1
The University of Montana - Western, 2The University of Alabama,
3
Texas A&M University-Commerce, 4University of Alabama,
5
Armstrong Atlantic State University
Better understanding of the heat strain that law enforcement personnel face
while wearing concealed soft body armor (SBA) can be used to help improve
comfort and safety and benefit both the officer and the public. PURPOSE: The
purpose of this study was to characterize the microclimate (micro-WBGT) under
a concealed Level II SBA during 60-min of moderately intense work at two
separate macro-WBGTs (26 °C and 30 °C), and to establish WBGT corrections to
allow prediction of heat strain in an individual wearing a concealed Level II SBA. METHODS: Nine volunteers (27 ± 4 yr) outfitted with a standard law enforcement
uniform and a traditional concealed Level II SBA, worked in a moderately warm
environment (WBGT = 26 °C). Each participant performed cycles of 12-min
of walking (1.25 L · min-1) and 3-min of arm curls (14.3 kg, 0.6 L · min-1) with a
5-min rest after every other cycle, for a total of 60-min. This trial was compared
to a previously completed 60-min work bout at WBGT of 30 °C. A two-way
repeated measures ANOVA with Post hoc Bonferroni and paired samples t-test
analysis was conducted using the variables “temp” and “time”. RESULTS: Results
indicated a greater difference between macro- micro-WBGTs existed at 26 °C
(8.9 °C difference) compared to the 30 °C (6.2 °C difference) macro-WBGT. This
represents a 26% increase in micro-WBGT at the macro-WBGT of 26 °C and a
17% increase in micro-WBGT at the macro-WBGT of 30 °C. A modified simple
linear regression prediction model was established for mean Micro-WBGT for
each macro-WBGTs after the plateau point at the 30-min mark. The derivation
regressions at 26 °C (R2 = 0.99), and 30 °C (R2 = 0.99) indicate that microWBGT could be predicted for each 15-min time at both macro-WBGTs tested for
individuals doing moderate intensity (300 Kcals · hr-1) work wearing concealed
Level II SBA. CONCLUSIONS: This research supports previous studies suggesting
WBGT adjustments are needed due to micro-WBGT elevation for the formulation
of safe threshold limit values for individuals wearing concealed Level II SBA. A
WBGT adjustment of about 6-10 °C, depending on the macro-WBGT, may be
necessary to ensure safety of the individual wearing a concealed SBA. However,
the degree to which intensity of work play a role in affecting this correction has
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yet to be tested. Future research should focus on various macro-environments
and intensities of work to further improve the accuracy of the WBGT corrections
and to start to establish a prediction model. PRACTICAL APPLICATIONS: This
research is the first step in attempting to quantify the effect of macro-WBGT on
individuals wearing concealed SBA. The findings from this research can begin to
be applied to law enforcement personnel and other individuals, including athletes,
who are required to wear non-permeable, concealed, protective equipment in
hot environments.
significant difference in any of the conditions. (Vp, CB: 3.73 ±. 29 m/s, C0.5-4
Collapsed x̄: 3.77 ± .30 m/s), (RVD, CB: 14.78 ± 2.84 m/s2, C0.5-4 Collapsed x̄:
15.30 ± 3.25 m/s2), (RFD, CB: 6643.13 ± 2902.00 N/s, C0.5-4 Collapsed x̄: 6989.99
± 2667.29 N/s) CONCLUSION: It appears there is no difference between CB and
all other conditions. These rest intervals may not acutely enhance Vp, RVD or
RFD. PRACTICAL APPLICATION: However, despite not enhancing Vp, RVD or
RFD athletes who are exploring various warm-up methods could utilize the fiveassisted vertical jumps, as it did not hinder performance.
Poster: 38
Poster: 41
PREDICTION OF MILITARY RELEVANT OCCUPATIONAL TASKS IN WOMEN FROM
PHYSICAL PERFORMANCE COMPONENTS
THE EFFECT OF LOW LOAD GLUTEAL ACTIVATION EXERCISES ON SPRINT
PERFORMANCE IN ELITE SKELETON ATHLETES
T. Szivak1, B. Nindl2, J. Maladouangdock1, C. Dunn-Lewis1, B. Comstock1,
D. Hooper1, S. Flanagan1, D. Looney1, W. DuPont1,
D. Dombrowski1, W. J. Kraemer1
D. W. Chapman1, T. Cannon2, L. Earles3, E. Bernotas3
1
University of Connecticut, 2Army Institute of Public Health
PURPOSE: This study sought to determine through multiple regression analysis
which measures were most predictive for a repetitive box lifting task (RBLT) and
for a load bearing task (LBT) (i.e. 2 mile, 34.1 kg rucksack carry) in 113 women
(23±4 yrs, 165±7 cm, 64±10 kg). METHODS: The RBLT consisted of the maximum
number of boxes (20.45 kg) that could be lifted from the floor to a height of
1.32m within a 10 min period (subjects were required to move between two
boxes 2.4 m apart between lifts). The LBT consisted of the minimum time to
traverse 2 miles while carrying a 34.1 kg military style rucksack. Independent
variables (IVs) included body mass, height, magnetic resonance imaging assessed
leg cross-sectional area, muscular strength 1RMs (squat, bench press, high pull,
boxlift), lower body explosive power (mechanical power assessed via jump
squats), muscular endurance (# of pushups in 2 min and # of squat repetitions at
a controlled rate with a 45 kg load [squat endurance test]) and aerobic capacity
assessed from a 2 mile run (2MR in secs). RESULTS: The mean±SD (range) for
the RBLT (# of repetitions) was 86±23 (20-159) and for the LBT (in seconds) was
2054±340 (1307-3447). The following equations were generated (p≤0.05): RBLT
(# of repetitions) = 57.4 + 0.2 (peak jump power) + 0.4(# of pushups in 2 min)
+ 0.15(# of repetitions during the squat endurance test) + 1.39(1RM boxlift in kg)
– 0.04(2MR in seconds) [R = 0.81; SEE = 14]; LBT (in seconds) = 1831 – 4.28(# of
repetitions during the squat endurance test) + 0.95(2MR in seconds) – 13.4(body
mass) [R = 0.73; SEE = 232]. CONCLUSIONS: The fact that the 2MR and squat
endurance test entered into both equations illustrates their utility as potential
predictors for successful military occupational performance. PRACTICAL
APPLICATIONS: These data suggest that women can augment their performance
in physically demanding occupations by participating in conditioning programs
targeting both muscular strength and endurance.
Poster: 39
INFLUENCE OF REST INTERVALS FOLLOWING ASSISTED JUMPING ON
PEAK VELOCITY, RATE OF VELOCITY DEVELOPMENT & RATE
OF FORCE DEVELOPMENT
V. L. Cazas1, L. E. Brown2, J. W. Coburn2, A. J. Galpin2, J. J. Tufano3,
J. C. Garner1, N. C. Dabbs4, H. Chander1
1
University of Mississippi, 2Center for Sport Performance, California State
University, Fullerton, CA, 3Edith Cowan University,
4
The University of Mississippi
The outcome of an athlete’s vertical jump is crucial in sports. If an athlete can
increase their peak velocity, rate of velocity development or rate of force
development during this explosive movement, vertical jump height may increase.
Assisted jumping, an over-speed concept, is a relatively new method to optimize
vertical jump performance. Research is needed to investigate how to optimally
manipulate programing variables to achieve the best training effect. PURPOSE:
To determine the effect of rest intervals on peak velocity (Vp), rate of velocity
development (RVD) and rate of force development (RFD) following assisted
jumping. METHODS: Twenty healthy recreationally trained males (age: 22.85 ± 1.84
yr, height: 179.44 ± 5.99 cm, mass: 81.73 ± 9.51 kg) attended five sessions. For all
sessions, subjects performed the same dynamic warm up then executed one set of
five consecutive assisted jumps at 30% body weight reduction. Assisted jumping
was performed with subjects standing on a force plate sampling at 1000 Hz. They
wore a full body harness attached to elastic bands which were attached to a rope
passed through pulleys on the ceiling. They then rested for 30 seconds (C0.5),
one (C1), two (C2), or four (C4) minutes, followed by three body weight jumps
with no assistance. Baseline jump (CB) height was measured without preceding
assisted jumps. RESULTS: All force plate data was collected and analyzed via
custom software. ANOVA revealed that Vp, RVD and RFD demonstrated no
1
Olympic Winter Institute of Australia, 2Australian Catholic University,
3
Australian Skeleton Team
PURPOSES: To determine whether the addition of low load gluteal activation
exercises to the current warm-up protocol of an elite skeleton athlete cohort would
improve 30 m upright sprint and sport specific bent-over sprint performance.
METHODS: 30 m sprint times using an electronic timing system were recorded
while athletes either sprinted in an upright ‘normal’ position or in a bent-over
position pushing a simulated skeleton sled during morning and afternoon testing
sessions using the control (no gluteal activation) or experimental intervention
(gluteal activation). The series of low load gluteal exercises were performed
in sequence with one set of 10 repetitions performed for each exercise. During
the exercises each athlete was instructed to maintain a neutral spine and verbal
cues were used to help achieve activation of the gluteal muscles. Subjects
were consistently instructed to engage the gluteal muscle group throughout
the exercise movements. The gluteal exercise program was performed under
supervision of the team Physiotherapist taking approximately 10 minutes to
complete. The seven low load gluteal exercises were double leg bridge, side lying
hip abduction, quadruped lower extremity lift, side lying gluteal clam in 60°, prone
single leg hip extension, body weight squats, hip abduction in quadruped (‘fire
hydrant’). RESULTS: Morning upright 30 m sprint times in the control intervention
were significantly (P<0.01, ES=0.33) faster than in the experimental intervention
(4.041 ± 0.1269 s for control vs 4.159 ± 0.1300 s for experimental). Afternoon
upright 30 m sprint times in the experimental intervention were significantly
(P<0.001, ES=0.24) faster than in the control intervention (4.152 ± 0.1361 s for
control vs 4.048 ± 0.1367 s for experimental). Afternoon bent-over 30 m sprint
times showed no statistical difference (P=0.07, ES=0.29) between control or
experimental interventions (4.905 ± 0.1903 s for control vs 4.743 ± 0.2173 s for
experimental). Comparison of control and experimental interventions over time
highlighted that upright 30 m sprint time was significantly (P<0.01) improved in
the morning and afternoon sessions respectively (4.041 ± 0.1269 s for control AM
vs 4.152 ± 0.1361 s for control PM; 4.159 ± 0.1300 s for experimental AM vs 4.048
± 0.1367 s for experimental PM). Bent-over 30 m sprint performance showed a
19.5% decrement when compared to upright sprint times (4.908 ± 0.1065 s for
bent-over vs 4.100 ± 0.06211 s for upright). CONCLUSION: The results indicate that
the addition of low load gluteal activation exercises in this athlete population can
improve upright/bent-over 30 m sprint performance, regardless of the influence
of diurnal fluctuations. PRACTICAL APPLICATION: The ease of implementation
with minimal risk of injury to the athlete suggest that low load gluteal activation
exercises should be incorporated as the standard pre-competition warm-up
protocol for skeleton athletes.
Poster: 42
DETERMINING PERFORMANCE DECREMENTS DURING SQUAT JUMPS
PERFORMED WITH VARIOUS LOADS
P. Comfort1, C. Gray1, J. Rogers1, M. Thomasson1
1
University of Salford
The optimal power load for squat jumps (with no countermovement) has been
shown to be lower than the loads usually recommended for power training using
Olympic lifts. Lower relative loads during squat jumps may permit the performance
of additional repetitions prior to the onset of fatigue compared to heavier loads.
PURPOSE: To identify the occurrence of decrements in performance, defined as a
statistically significant decrease in peak power or jump height, during squat jumps
with various loads. METHODS: Male collegiate athletes (n=16; 22.5 ± 1.5 years, 178.5
± 7.2 cm, 72.85 ± 8.59 kg, one repetition maximum (1-RM) back squat = 129.6 ±
9.75 kg). Participants performed sets of ten repetitions of squat jumps, using five
loading conditions as determined by their best 1-RM performance (0, 10, 20, 30,
40% 1-RM back squat). The loading conditions were allocated in a randomized
and balanced order, with 5-6 min rest permitted between sets. Squat jump
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
performances were assessed using a ballistic measurement system incorporating
a force plate (sampling at 600Hz) to record the vertical ground reaction force
and thelinear position transducer (LPT) to record vertical displacement of the bar.
To determine peak power, velocity of the centre of gravity (COG) of the system
(barbell + body) was calculated from vertical ground reaction force (Fz) time data,
based on the relationship between impulse and momentum, in which impulse is
equal to the changes in momentum (forward dynamics approach). Power applied
to the system was calculated as the product of velocity of the COG of the system
and Fz at each time point. RESULTS: Repeated measures analysis of variance
(RMANOVA) revealed no significant differences (p>0.05) in peak vertical ground
reaction force (vGRF), peak power or displacement, between repetitions in each
loading conditions. A further RMANOVA, including Bonferroni post-hoc analysis,
demonstrated that peak power output (3760.57 ± 1014.45 W) occurred in the
0% 1-RM loading condition, which was significantly (p≤0.01) greater than the
30% 1-RM (2964.13 ± 913.62 W) and 40% 1-RM (2809.15 ± 626.98 W) conditions,
although this was not statistically (p<0.05) greater than the 10% 1-RM (3483.33 ±
839.27 W) or 20% 1-RM (3238.13 ± 839.27 W) conditions. CONCLUSIONS: These
findings indicate that when performing squat jumps (with no countermovement)
with a load ≤40% 1-RM back squat, ≥10 repetitions can be completed without
inducing fatigue. PRACTICAL APPLICATIONS: When incorporating squat jumps
(using relative low loads) into power training programs, it may be beneficial
to recommend repetition ranges of ≥10, as this study found no decrements in
performance below this repetition range.
Poster: 43
THE RELATIVE IMPORTANCE OF OPEN- AND CLOSED-SKILL AGILITY
PERFORMANCE FOR SELECTION AS A STARTER IN ADULT MALE BASKETBALL
PLAYERS
each bout. Perceived Recovery Status Scale (PRS) was recorded prior to the start
of each trial. Heart rate (HR), RPE (0-10 Omni scale), and Perceived Readiness
Scale (PR) was recorded after every sprint and session RPE (S-RPE) was recorded
20min after completing the entire bout. RESULTS: Results from a 2 (condition) x
3 (bout of sprints) repeated measures ANOVA revealed a significant main effect
of condition on average sprint time (p=0.03), HR (p<0.01), RPE (p=0.01), and
PR (p=0.02). Post-hoc follow-ups show significantly faster average sprint times
during the EU vs DY trial during the second (4.87±0.29 vs 5.03±0.33s; p =0.01)
and third bout of sprints (4.91± 0.29 vs 5.12±0.44s; p=0.02). HR was also found
to be significantly lower for EU during the second bout (158 vs 168 bpm; p =
0.05) and third bout (161 vs. 171 bpm; p = 0.01). Post-hoc measures also show
significantly decreased (p<0.05) feelings of recovery (PRS) prior to exercise and
increased (p<0.05) perceptual strain before each bout (PR) during the second
and third bouts of repeated sprint work (i.e., RPE and PR) and following the total
session (S-RPE) in the DY condition. CONCLUSION: Dehydration impaired sprint
performance, decreased perception of recovery status prior to exercise, increased
perceived exertion, and elevated heart rate. Results highlight the importance
of adequate hydration during intermittent sprint performance. PRACTICAL
APPLICATION: Deleterious effects of dehydration are not limited to endurancebased sports. Athletes in intermittent sports are encouraged to pay special
attention to hydration during practices without ignoring potential day to day fluid
deficits. ACKNOWLEDGEMENTS: No sources of funding were used to assist in
the preparation of this abstract. The authors have no conflicts of interest that are
directly relevant to the content in this abstract.
Poster: 45
ASSISTED JUMP TRAINING MAY ALTER TEMPORAL MECHANICS DURING
BODYWEIGHT JUMP PERFORMANCE
A. M. DuBois1, T. L. Beaudette1, L. E. Brown2
V. Dalbo1, A. Scanlan1, P. Tucker1
1
Central Queensland University
Purpose: Open-skill agility qualities have yet to be described in adult male
basketball players. Further, the importance of open- and closed-skill agility for
team selection remains unknown. Thus, this study aimed to: (1) describe the openand closed-skill agility of adult male basketball players and (2) compare these
properties between starting and non-starting players. Methods: A cross-sectional
between-group design was used. Six starting (mean ± SD: playing time, 30.1 ± 8.8
min; age, 30.5 ± 4.8 yr; height: 192.1 ± 7.7 cm; body mass: 100.5 ± 15.0 kg; VO2max,
48.4 ± 6.6 mL∙kg-1∙min-1) and six non-starting (4.3 ± 3.6 min; 21.3 ± 5.0 yr; 185.7
± 7.4 cm; 94.4 ± 17.9 kg; 50.6 ± 3.9 mL∙kg-1∙min-1) state-level basketball players
completed multiple trials for the Change of Direction Speed Test (CODST) and
Reactive Agility Test (RAT). Results: No statistically significant between-group
differences were evident for CODST movement time (starters: 1.652 ± 0.047
s; non-starters: 1.626 ± 0.040 s, p = 0.68; effect size = 0.24) or RAT decisionmaking time (starters: 110.7 ± 11.0 ms; non-starters: 147.3 ± 14.2 ms, p = 0.08;
effects size = 1.18). Starters possessed significantly faster RAT movement times
than non-starters (2.001 ± 0.051 s vs. 2.182 ± 0.040 s; p = 0.02; effect size = 1.61).
Conclusions: Our findings suggest that closed-skill agility properties are similarly
developed in starting and non-starting players. In contrast, facets of open-skill
agility performance such as anticipation, visual scanning, pattern recognition, and
situational knowledge, might be central distinguishing qualities for team selection
in basketball. Practical Applications: The development of perceptual and cognitive
components of agility performance might be important in distinguishing starting
from non-starting players in basketball. Basketball coaching and conditioning
staff should incorporate sport-specific reactive training drills for all players during
the annual conditioning plan. Poster: 44
IMPACT OF 3% DEHYDRATION ON INTERMITTENT SPRINT PERFORMANCE
J. Davis1, K. Allen1, M. Laurent2, M. Green3, N. Stolworthy1,
T. Welch4, M. Nevett1
1
University of Montevallo, 2Bowling Green State University,
University of North Alabama, 4University of South Florida
3
PURPOSE: Hypohydration of 2% has been shown to impact aerobic exercise but
the critical level in which anaerobic performance is affected has been suggested
to occur at a higher level of dehydration. This study examined the effects of
3% dehydration on intermittent sprint performance and perceptual measures.
METHODS: Eight collegiate baseball players completed the intermittent sprints
either dehydrated (DY) of 3% body mass or euhydrated (EU). All participants
body mass was reduced by 3% via exercise in the heat with controlled fluid intake
occurring 1day prior to the trial. Participants completed 24 x 30meter sprints,
divided into 3 bouts of 8 sprints with 45sec rest between each sprint and 3min
1
California State University, Fullerton, 2Center for Sport Performance,
California State University, Fullerton, CA
INTRODUCTION: It has been demonstrated that performing assisted vertical
jumps (a form of overspeed training) acutely improves vertical jump performance
through a potentiating effect that increases velocity at take off. However, assisted
jumping may also affect limb kinetics of the jump by altering the time intervals
between peak force, peak power and peak velocity. Given these acute changes in
vertical jump performance, it is possible that assisted vertical jump training could
chronically affect temporal vertical jump mechanics. PURPOSE: To investigate
the effects of assisted jump training on temporal jump mechanics during body
weight vertical jumps. METHODS: Eight NCAA Division I women’s volleyball
players (19.25 ± 0.89 yrs; 182.84 ± 3.72 cm; 72.29 ± 9.28 kg) performed three
maximal baseline countermovement vertical jumps with arm swing followed
by four weeks of assisted plyometric jump training. Throughout assisted jump
training, subjects wore a full body harness and were connected to a resistance
band pulley system hanging from the ceiling that reduced their body weight
as the bands were pulled tight. During the first two weeks, subjects performed
2 sets (week 1) and 3 sets (week 2) of 10 jumps at 30% bodyweight reduction.
During the last two weeks, subjects performed 2 sets (week 3) or 3 sets (week
4) of 10 jumps at 40% body weight reduction. After training, subjects performed
three maximal post countermovement vertical jumps with arm swing. All jumps
were performed on an AMTI force plate sampling at 1000 Hz. The time at peak
force, peak power and peak velocity were calculated during each maximal jump
via custom LabVIEW software and the time deltas between 1) peak force and
peak power (ΔFPTIME), 2) peak force and peak velocity (ΔFVTIME) and 3) peak
power and peak velocity (ΔPVTIME) were calculated. RESULTS: There were no
significant differences between ΔFPTIME (pre = 0.098 ± 0.122 s; post = 0.065
± 0.092 s; p = 0.378), ΔFVTIME (pre = 0.140 ± 0.122 s; post = 0.107 ± 0.092 s; p
= 0.382) or ΔPVTIME (pre = 0.041 ± 0.003 s; post = 0.045 ± 0.003 s; p = 0.613)
from baseline to post test. CONCLUSIONS: Although there were no significant
differences in time deltas, there was a noticeable trend towards decreasing time
intervals between 1) peak force and peak power and 2) peak force and peak
velocity. Given that the athletes trained for a relatively short period of time,
this trend suggests that assisted jump training could alter the mechanics of the
jump and might lead to temporal decreases that could improve vertical jump
performance. PRACTICAL APPLICATIONS: Altering temporal mechanics of the
jump may lead to improvement in vertical jump performance, making assisted
vertical jump training a potential training tool for athletes that are dependent on
vertical jumping for success in their sport. Therefore, it is suggested that assisted
plyometric jump training be incorporated into a jumping athletes training routine. NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 46
ELECTROMYOGRAPHY ACTIVITY OF THE GLUTEUS MEDIUS AND GLUTEUS
MAXIMUS MUSCLES USING A GOLF SPECIFIC POWER HIP TRAINER IN
COLLEGIATE GOLFERS
J. Ghigiarelli1, K. Sell1, J. Ng1, A. Rothstein1
1
Hofstra University
Low handicap golfers are reported to have increased pelvic rotational speed
as well as increased gluteus medius and maximus strength compared to high
handicap golfers. This has resulted in an increased emphasis to be placed on golf
specific strength training programs and the development of innovative training
tools for helping establish a foundation of flexibility and strength. No study has
investigated the muscle activity of the golf specific power hip trainer (GSPHT) in
comparison to traditional golf training exercises. PURPOSE: To examine muscle
activation of the right and left gluteus medius and gluteus maximus muscles
during four different hip rotational exercises: (1) medicine ball rotational throws,
(2) resisted downswing using an elastic band, and (3) an open and closed stance
bout with the GSPHT. METHODS: Six male (age 20 ± 0.8 yr, mass 73 ± 10kg,
handicap 1 ± 1) and five female (age 20.6 ± 0.5 yr, mass 68 ± 15.6kg, handicap 5
± 3) division 1-A golfers completed four separate training sessions consisting of
2 sets of 15 repetitions of the medicine ball throw, resisted elastic band tubing,
GSPHT closed, and GSPHT open exercises. At the beginning of each training
session, maximum voluntary isometric contraction (MVIC) manual muscle testing
for the gluteus medius and gluteus maximus muscles were performed to record
maximum electromyography (EMG) activity. The EMG amplitude of each muscle
response during each exercise was expressed as a percentage of the maximum
EMG amplitude for that muscle. %MVIC of each muscle response was analyzed
to assess the level of muscle activity simulating the downswing phase movement
of each exercise. RESULTS: The medicine ball and hip trainer closed position
produced the most overall muscle activation of 41.2% and 34.2% respectively,
with emphasis on the right gluteus medius and gluteus maximus. The greatest
relative % peak EMG was observed in the right gluteus medius (56.6%) for hip
trainer closed and right gluteus maximus (53.5%) for medicine ball throws. CONCLUSIONS: The GSPHT does effectively isolate the gluteus medius muscles
specifically when twisting in the closed position against a spring loaded resistance. The medicine ball rotational throws recruits more overall hip muscle activation
which is due to the heavier loading that can be provided by the resistance of the
ball and the athlete is able to engage more muscle activity due to the nature of
the exercise. PRACTICAL APPLICATIONS: The GSPHT can be an effective tool to
increase gluteus medius strength which will allow more rotational velocity during
the downswing phase of the golf swing. Subsequently this may lead to increased
club head velocity and increased driving distance. Poster: 47
REPEATED MEASURES OF PEAK POWER, VERTICAL JUMP, AND MOOD STATE
IN NCAA-DI WOMEN, BASKETBALL PLAYERS DURING PREPARATORY AND
COMPETITIVE TRAINING PERIODS
M. T. Jones1, G. L. Coleman1, T. Rusbasan1, S. Walls1
1
George Mason University
Purpose: Previous research has studied changes in power output or mood during
competitive seasons. The current study was designed to investigate whether or
not changes occur in peak power, vertical jump, or mood state over the course
of 9-week (wk) preparatory and 11-wk competitive training periods in collegiate
basketball (BB) athletes. Methods: Demographic data (M + SD) were obtained
from 14 NCAA-DI women athletes age: 20.5±1.1 yr; height: 175.9±6.6 cm; weight:
70.7±9.9 kg; BMI: 22.8±2.3 kg·m-2; and %fat: 19.6±6.3%. Countermovement
vertical jump height (CMVJ), peak power (PP), and mood state were measured
each wk at the same time and day for the 6-wk off-season (OS) training and 3-wk
pre-season (PS) periods. In BB season (IS), measures were limited to wk 11-16, 18,
and 20. Subjects were divided into starters (S, n=7) and non-starters (NS, n=7)
based upon total minutes played during the BB season (S> 57% vs NS < 45%
total game minutes). A force plate (AMTI, Inc.) and Vertec® (Sports Imports) were
used concurrently to measure PP and CMVJ, respectively. Athletes were skilled
jumpers who were instructed to jump as high and quickly as possible with knees
and ankles extended. Power was calculated from vertical ground reaction force
(Fz) and the center of mass vertical acceleration (COMvel). Athletes were given 3
CMVJ attempts separated by 1 min each. To assess mood state changes athletes
completed the Brief Assessment of Mood (BAM), which measures 6 affective
states: (1) tension (TEN), (2) depression (DEP), (3) anger (ANG), (4) vigor (VIG),
(5) fatigue (FAT), and (6) confusion (CON), and is a commonly used method for
assessing mood. Data were analyzed as percent change from OS-wk 1 measures.
Two-way repeated measures ANOVAs were used to analyze PP, CMVJ, and the 6
BAM affective states between groups. Alpha level was set at p<0.05 for ANOVAs,
and p<0.10 for Bonferroni tests due to the high number of pairwise comparisons
required for the 20-wk period. Results: PP increased 6.2% (p=0.001) from OSwk 1 to OS-wk 6 (3860+523.1 vs 4097.8+553.4 watt) for all athletes. No changes
occurred between S and NS groups for PP and CMVJ over the OS, PS, or IS periods.
Of the 6 BAM affective states, significant changes between groups were found for
TEN (NS>S, p=0.001), VIG (NS>S, p=0.009),and FAT (S>NS, p=0.001)while DEP,
ANG, and CON remained unchanged. Bonferroni’s post-hoc test showed ratings
of FAT for NS were lower in wk 7 (p=0.051), wk 11 (p=0.064), wk 16 (p=0.034),
and wk 18 (p=0.072) compared to S. Conclusions: Mood state has been shown
to be sensitive to changes in training load and, therefore, can be indicative of
how well an athlete adapts to changes in training programming. In the current
study, all athletes improved PP over the 6-wk OS training period with no further
increase found in the PS and IS periods. During PS and IS, the S group exhibited
greater change in the negative descriptor of FAT. The NS displayed higher values
in the positive descriptor of VIG. This may be a result of S having more negative
feelings in their response to the increased training load as PS progressed into the
IS period. Practical Application: The administration of the BAM to team members
might give prior indication of actual team performance. These results support the
usefulness of monitoring psychological and physical markers for preparatory and
competitive training periods. Training load can then be adjusted and adequate
recovery methods provided as necessary.
Poster: 48
THE IMPACT OF THE 1RM POWER CLEAN ON POST ACTIVATION
POTENTIATION OF USING OVERWEIGHT IMPLEMENTS IN THE OVERHEAD
BACK SHOT PUT THROW
L. W. Judge1, D. Bellar2, B. Craig3, E. Gilreath4, S. Cappos5,
E. Wanless1, C. Ethredge6
Ball State University/School of PE, Sport, and Exercise Science, Muncie,
IN, 2University of Louisiana at Lafayette, 3Ball State University/Human
Performance Laboratory, Muncie, IN, 4Indiana State University/Department of
Athletics, Terre Haute, IN, 5University of Iowa,
6
University of Louisiana at Lafayette, Lafayette, La
1
Although the value of strength to shot putting appears undisputable, several
authors have recommended that explosive power is actually a more important
physical characteristic. Debate about the effectiveness of post activation
potentiation (PAP) is mostly attributed to the characteristics of the conditioning
activity (CA) and the training status of the subjects. PURPOSE: To examine the
relationship between 1RM in the power clean to the acute effects of heavy and
light implements on subsequent OHB shot put performance. METHODS: The
participants included 41 athletes (20.9±1.18yrs) from two NCAA Division I schools
(n=23 male, n=18 female). Participants reported to the field on four separate
occasions. On the first visit, participants became familiar with the technique of the
OHB throw. On the second through forth visits, participants warmed up (~ 15 min
of dynamic stretching) and then completed three, maximal effort, OHB throws
with a competition shot put. Each attempt was preceded by one of three randomly
assigned treatments. The treatments included three OHB throws with a shot 1kg
heavier or 1kg below the standard weight, or the competition weight (7.26k men,
or 4kg women). Mean distance for OHB throw and fatigue was examined post
treatment (control, light shot put warm up, heavy shot put warm up) via Repeated
Measures ANOVA with Bonferroni corrected post hoc analysis. The relationship
of strength to the treatments was examined via Pearson’s Bivariate Correlations. RESULTS: Statistical analysis by Pearson’s bivariate correlations revealed that the
change in average performance between the heavy warm-up and the control
condition was related to the 1 RM power clean for the athlete that was reported
by the coach (r= 0.338, p=0.045), but not the squat (p=0.302, p=0.068) or the
bench press (r= 0.271, p=0.10). Change between the light warm-up and control
was not related to any 1RM numbers reported by the coach of the athlete (r< 0.155,
p>0.359). Results of the repeated measures ANOVA demonstrated a significant
main effect for treatment in regard to average distance (F=6.276, p=0.003).
The heavy shot put warm-up resulted in the greatest mean performance
(14.39m±1.82) followed by the light shot put warm up (14.18m±1.68) and the
control (14.15m±1.70). Post hoc testing suggested that the heavy shot put warmup resulted in significantly better mean OHB performance than either the light
shot put warm-up (t=2.983, p=0.0048, ES=0.472, Power=0.901) or the control
shot put warm-up (t=3.349, p=0.0018, ES=0.513, Power=0.939). CONCLUSION: In
moderately trained collegiate athletes, the use of heavy shot puts as part of the
pre-activity warm-up does enhance OHB performance. The change in average
performance between the heavy warm-up and the control condition was related
to the 1 RM power clean. PRACTICAL APPLICATIONS: Athletes with a resistance
training background can utilize the concept of PAP in training and competition to
improve performance in throwing events.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 49
ASSESSMENT OF UPPER BODY ANAEROBIC POWER AND CAPACITY IN
COMPETITIVE MALE CURLERS
D. M. Kivi1, D. W. Smith1, A. D. Blando1
1
Lakehead University
Sweeping is one of the most physically demanding skills in the sport of curling,
requiring balance, coordination, strength, and endurance. The purpose of
sweeping is to increase the distance the stone will travel down the ice, and to
reduce the amount of lateral deflection or “curl.” Two members of the team at
a time are responsible for sweeping, which is performed directly in front of the
stone. They may be required to sweep for up to 26 seconds per shot at a maximal
effort. This is then followed by 30-180 seconds of recovery while the opposing
team is delivering their stone. Players may sweep up to 6 stones per end, for
ten ends during a game. Effective sweeping is characterized by a rapid backand-forth movement of the broom head combined with a large downwards force. To date, no research has been conducted to examine the upper body anaerobic
performance characteristics of curlers. PURPOSE: The purpose of this study was
to examine the upper body anaerobic power and capacity in competitive male
curlers. METHODS: Twelve male curlers (age: 18.2 ± 1.2 yrs, height: 179.0 ± 7.5 cm,
mass: 73.7 ± 10.0 kg) were recruited to participate. All had previously participated
in regional, provincial, or national curling events, and players from each of the
four positions on the team (lead, second, third, and skip) were included. The
participants first completed a standardized warm-up, which involved 5 minutes
of pedalling at a self-selected pace with 5-second maximal effort sprints at 2, 3,
and 4 minutes against a resistance of 3% body mass. Starting from a cadence of
60 revolutions per minute, the participants performed the 30-second upper body
Wingate anaerobic test at a maximal effort. Testing was completed using a cycle
ergometer which had been modified for the upper body, with the resistance set at
4.0% of body mass. Relative peak power, average power, and fatigue index were
measured, along with the amount of time that a power output greater than 90%,
80%, and 70% of peak power was sustained. RESULTS: The mean relative peak
power and average power for all participants were found to be 5.37 ± 0.72 W/kg
and 4.48 ± 0.65 W/kg, respectively. The mean fatigue index was 37.27 ± 7.79 %. Over the duration of the test, the participants were able to sustain power outputs
greater than 90% of peak power for an average of 12.4 ± 2.6 sec, greater than
80% for 18.9 ± 3.2 sec, and greater than 70% for 24.1 ± 3.4 sec. CONCLUSIONS:
This research provides insight into the upper body anaerobic performance of
competitive male curlers. The results suggest that curlers are capable of working
at greater than 90% of their peak power for approximately half the time that
the stone is travelling down the ice, and greater than 70% of their peak power
while sweeping over full length of the ice. PRACTICAL APPLICATION: Because
curlers may be required to sweep at maximal efforts for prolonged periods of
time, an understanding of upper body anaerobic power and capacity can assist
with the development of curling-specific training programs. Athletes and coaches
may also use this information to help develop strategies to optimize sweeping
performance during competitive play by knowing the amount of time that near
maximal power outputs can be sustained. ACKNOWLEDGEMENTS: This study was
funded by the Northern Ontario Curling Association.
Poster: 50
RELATIONSHIP BETWEEN 5, 10, AND 40 YARD SPRINTS AND
STANDING LONG JUMP PERFORMANCE
D. P. Knorr1, C. Goodman2, C. Capps1, B. Ashworth1, M. Morton1, K. N. Kijowski1,
N. Triplett1, T. Erickson3, J. McBride2
1
Appalachian State University, 2Appalachian State University/Neuromuscular &
Biomechanics Laboratory, Department of Health, Leisure & Exercise Science,
Boone, NC, 3Appalachian State
Running performance consists of a combination of aerobic and anaerobic
capabilities varying based on the distance of the event. It is also may be
dependent on factors relating to lower body power. Lower body power is
commonly assessed by various modes of jumping tests. PURPOSE: The purpose
of this study was to determine if there was a correlation between 5, 10, and
40 yard sprints and standing long jump performance. METHODS: Participants
in this investigation visited the Holmes Convocation Center’s Neuromuscular &
Biomechanics Laboratory (NBL) for two testing sessions. The two sessions were
separated by at least 48 hours. On Day 1 height and weight was obtained for each
subject. In addition, sprint times of the 40 yard dash as well as 5 yard and 10 yard
splits were measured using an infrared timing system (Brower Timing Systems,
Draper, UT) performed on a standard track surface. On day two participants came
in and randomly performed a set of standing long jumps. RESULTS: There were
strong negative correlations between standing long jump performance and 5 yard
(-.86), 10 yard (-.87), and 40 yard (-.68) sprint performances. CONCLUSIONS:
The lower body power associated with standing long jump performance may be
a good predictor of short sprinting performance of up to 40 yards. PRACTICAL
APPLICATIONS: Training for lower body power with movements such as the
standing long jump may help maximize performance in sprinting during different
sporting events.
Poster: 51
RELIABILITY OF ISOKINETIC PARALLEL BACK SQUAT
H. Kobayashi1
1
Sapporo International University
The purpose of the present study was to examine the reliability of isokinetic
parallel back squat to determine if repeated measures on the same subjects
yielded reliable results. Eight male subjects performed parallel back squat on
5 occasions. The subjects performed six squat tests using the BTE-Primus at
angular velocities of 30, 60, 90, 120, 150 and 180 degree per second. Absolute
measures of peak power per revolution were recorded. Analyses of variance
(ANOVAs) were performed to analyze the mean data between six squat tests,
while intraclass correlation coefficients (ICCs) were performed for reliability. The
intraclass correlation coefficients (ICCs) for the eccentric phase of squat exercise
ranged from 0.85-0.92 while for the concentric phase of squat exercise of ICCs
values showed under 0.80 except at a speed of 30°/s. To obtain reliable power
data, more familiarization seems to be needed when they perform modified
versions of common multijoint strength tests. The marked differences in reliability
resulting from variation in the concentric phase of squat exercise suggests that
the reliability of a test needs to be reestablished when it is modified, before it is
used to assess subject strength performance. Acknowledgements: This work was
supported by MEXT KAKENHI Grant Number 12863320.
Poster: 52
INVESTIGATION OF THE NSCA MINIMAL READINESS STANDARDS FOR
MUSCULAR FITNESS, BALANCE AND PERFORMANCE OF PLYOMETRIC
EXERCISE IN COLLEGE ATHLETES
J. E. Kovaleski1, G. Palsson2, J. J. Schwind1, S. M. Mitchell1, W. Liu1,
L. R. Gurchiek1, R. J. Heitman1
1
University of South Alabama, 2Stykkisholmur Fitness Center
The NSCA guidelines specify that prior to beginning high-intensity lowerbody plyometric training, the athlete should be able to minimally squat 1.5 ×
bodyweight (BW), be able to perform five squat repetitions with 60% BW in five
seconds or less, and perform the 30-second single leg standing half-squat without
falling. The pre-training evaluation data supporting these minimal standards for
plyometric training are based on evidence obtained mostly from observational
studies and practitioner experience. These standards also appear to be based
on the premise that both men and women possess equal strength, speed, and
balance prerequisites prior to plyometric training. Purpose: To determine the
percentage of college athletes who met the minimal readiness standards for
plyometric training and to examine differences between athletes who passed
and failed the readiness standards using the vertical jump (VJ) as a plyometric
performance indicator. Methods: Forty-four male (99.8 ± 19.3 kg; 185.4 ± 8.2 cm;
209.2 ± 43.8 kg 1-RM squat) and 32 female (68.1 ± 8.3 kg; 179.7 ± 11.2 cm; 161.9 ±
66.0 kg 1-RM squat) NCAA Division I football, basketball, soccer, and volleyball
athletes, aged 19 to 23 years participated. Each subject performed the 1.5 × BW
back squat, the 5-repetition back squat at 60% BW, and the 30-second singleleg half squat. Jump height (cm) was measured using an accelerometer for the
single-and double-leg VJ and from a depth jump performed from an 18 inch high
box. The athletes who passed and failed the readiness standards were compared
for differences in jump performance using Independent samples t-tests. Results:
All male and female athletes successfully completed the 30-second single-leg half
squat for balance. Forty-two (96%) of the 44 male athletes and 12 (38%) of the 32
female athletes were able to squat 1.5 × BW. The double- and single-leg and depth
jump heights were not significantly different (ρ ≥ .05) between males who passed
and failed the 1.5 × BW squat. Whereas, the female athletes who squatted 1.5 x
BW jumped significantly higher than those who did not (double-leg: 33.8 ± 6.3 cm
versus 28.9 ± 5.0 cm, ρ = .02; single-leg: 22.2 ± 3.9 cm versus 18.7 ± 3.3 cm, ρ =
.01; depth jump: 52.6 ± 9.0 cm versus 47.2 ± 5.9 cm, ρ = .049). Seventeen (39%) of
the 44 male athletes and none of the 32 female athletes completed 5-reps of the
back squat at 60% BW in less than 5 seconds. No additional statistical analyses
for the female athletes were performed using this readiness standard because
none of the women passed this readiness standard. No significant difference (ρ
≥ .05) for the males who passed and failed the 60% BW squat was found for
either the double- or single-leg jump heights. Whereas, the male athletes who
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
passed the 60% BW squat performed the depth jump significantly better than
those who did not (72.3 ± 11.6 cm versus 65.9 ± 8.3 cm, ρ = .04). Conclusions: This
research identified that the 30-second half-squat balance test and the 1.5 × BW
back squat are effective discriminators of readiness for male and female athletes.
The 60% BW back squat was found to be an appropriate indicator of readiness
for the male athletes, but not for the female athletes because none of the female
athletes passed this readiness standard. Practical Applications: A revised backsquat speed standard with a greater discriminating power should be developed to
assess plyometric readiness in female athletes. These findings have implications
for injury prevention when evaluating readiness prior to implementing highintensity plyometrics.
Poster: 53
SELECTED PREDICTORS OF VOLLEYBALL PLAYING ABILITY IN FEMALE
COLLEGIATE VOLLEYBALL PLAYERS
J. Miller1, B. J. AlSarraf2
1
Oklahoma City University, 2Department of Physical Education and Sport,
College of Basic Education in Kuwait
PURPOSE: Selecting valid assessments to evaluate the effectiveness of a training
program on actual on court volleyball playing performance is a challenge for the
strength and conditioning professional. Additionally, assessment selection for the
purpose of talent identification for volleyball playing ability is equally important
and challenging for the volleyball coach. The purpose of this study is to examine
the strength of the relationship between the assessments: single response squat
(SJ), vertical (VJ) and approach jump (AJ), and passive ankle dorsiflexion (PAD)
with a quantified coach’s rating (CR) of volleyball playing ability. METHODS: Eight
female collegiate volleyball players (age=19.5±1.3yrs; height = 68±3in; weight =
158±15lbs) volunteered for the study. All testing took place within a week of the
last volleyball match of the season. Upon arriving for testing athletes performed
a 5 min general warm up on the cycle ergometer. Following the general warm up
participants performed multiple sets of low intensity jumps including two sets
of the SJ and VJ. Following the warm up period the order of assessment was
SJ, VJ, AJ and right (RDF) and left (LDF) PAD. For the SJ, hands were placed
on the on hips and the participants achieved/held a parallel squat for 4 second
before jumping. There was no hold time with the VJ and participants were
permitted to use a countermovement and arm swing. The AJ was performed by
the participants utilizing the 3-step volleyball specific approach before jumping.
Athletes performed as many jumps as necessary until two successive jumps
were no longer higher than the best recorded score. A 30sec rest was observed
between all jump assessments/attempts. All jump assessments were conducted
on a contact mat (Just Jump, Probotics, Huntsville, AL). PAD was assessed after
jump assessments utilizing a tape measure placed on the floor perpendicular to a
wall. With shoes removed, athletes placed the knee of the selected leg against the
wall while sliding the heel away from the wall. The distance from the posterior side
of the heel to the wall was measured and recorded for both legs, PAD scores were
normalized to the athletes’ height. The difference between PAD scores for the
right and left leg was calculated to assess asymmetry. CR of the athletes’ volleyball
playing ability was provided by the athlete’s volleyball coach in response to a
standardized question which quantified volleyball playing ability using a 10pt scale
(10=superior, 1=inferior). All jump scores were analyzed as absolute and relative
values (relative to bodyweight and body mass index). SJ, VJ, AJ and PAD scores
were correlated with the CR using a Spearman’s rank correlation (ρ). RESULTS:
Moderate strength correlations existed between CR and the AJ (ρ = 0.51) and AJ/
BMI (ρ = 0.32), and right (ρ = -0.34) and left (ρ = -0.55) PAD. CONCLUSIONS:
The AJ appears to be the best predictor of general volleyball playing ability when
playing ability is quantified by a volleyball coach. Additionally, some passive ankle
stiffness may be important in jumping ability and also contribute to a reduction
contact time with the ground during changes of direction yielding improved
general performance in the sport of volleyball as assessed by a volleyball coach.
PRACTICAL APPLICATION: The sport-specific AJ is the best predictor of general
volleyball playing ability as determined by a volleyball coach and therefore may be
an important assessment when evaluating potential collegiate volleyball players.
The AJ may also serve as a measure that can effectively mediate the degree of
transfer from a strength and conditioning training program to actual volleyball
playing ability.
Poster: 55
POST-ACTIVATION POTENTATION EFFECTS FROM ACCOMMODATING
RESISTANCE COMBINED WITH HEAVY BACK SQUATS ON 10-YARD SPRINT TIME
C. Reyes1, J. Van Dorin2
1
Concordia University, School of Physical Therapy/Northern Illinois University
2
PURPOSE: Applying accommodating resistance through the use of elastic bands
combined with traditional plate-loaded resistance has been demonstrated
to be effective in improving neuromuscular attributes that are important for
performance in many different sports and activities. The purpose of this study
was to determine if 10-yard sprint performance can be acutely enhanced after
several sets of heavy back squats with or without the addition of elastic bands. METHODS: Twenty recreationally resistance-trained males (age 23.3 ± 4.4 years;
height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) performed pre-post testing on 10yard sprinting time, as measured by an electronic timing system. Three different
interventions were implemented in randomized order between pre-post 10-yard
sprints to manipulate sprint time. On three days, separated by at least 72 hours,
subjects either rested for five minutes (CTRL), performed 5 sets of 3 repetitions
at 85% of their 1RM with standard weight load (STND), or performed 5 sets of
3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from
elastic band tension (BAND) between pre-post 10-yard sprint testing. Posttesting for 10-yard sprint time occurred immediately after the last set of the heavy
squats (Post-Immediate) and on every minute for 4 minutes after the last set
of heavy squats (Post-1min, Post-2min, Post 3-min, and Post-4min). RESULTS:
Repeated-measures ANOVA statistical analyses revealed no significant changes
in sprint time across post-testing times during the CTRL and STND condition. But during the BAND condition, when comparing the Post-Test Immediate
sprint time to Post-4min, 10-yard sprint time significantly decreased by 3.5%
(p = 0.002). CONCLUSION: The unique accommodating resistance of bands,
combined with the high neural stimulation of heavy back squats, could create
an optimal acute post-activation potentiation effect to increase neuromuscular
performance. PRACTICAL APPLICATIONS: Since a key to a successful start in a
sprint is explosive strength, practitioners and athletes can utilize accommodating
resistance combined with heavy lifting to properly prime the neuromuscular
system. This type of neuromuscular preparation could be viewed as an innovative
method of warming-up athletes needing high explosive strength. Poster: 56
RELATIONSHIPS BETWEEN IMPULSE AND PEAK POWER, PEAK VELOCITY, AND
PEAK FORCE IN ADOLESCENT SURFERS
T. T. Tran1, L. Lundgren2, G. Haff2, R. Newton3, S. Nimphius4, J. M. Sheppard5
1
Hurley Surfing Australia & Centre for Exercise and Sport Science, Edith Cowan
University, 2Centre of Exercise and Sport Science Research, Edith Cowan
University, Joondalup, Western Australia, 3Centre for Exercise and Sport
Science, Edith Cowan University, Joondalup, Western Australia,
4
Centre for Exercise and Sport Science, Edith Cowan University,
5
Surfing Australia & Edith Cowan University
Introduction: Countermovement jumps are a quick performance assessment
commonly used by strength coaches and sport scientists to measure lower
body explosive power. Previous research has stressed take-off velocity or peak
force to increase vertical jump height (JH). Further, previous research has shown
that impulse (IMP) can predict jump height however there is no research that
examines the relationship between IMP and the common jump variables of peak
power (PP), peak velocity (PV), peak force (PF) in adolescent surfers. Purpose:
To examine the relationship between IMP and PP, PV and PF during the vertical
jump in adolescent surfers. Methods: Twenty-eight competitive surfers (Females
= 11, Males = 17) participated in this investigation. They were separated into
two age groups (younger: < 16 yrs, n=13; older: ≥ 16 yrs, n= 15) to determine if
the strength in the relationship between IMP and PP, PV and PF varied by age.
Subjects performed three self-selected countermovement jumps (CMJ) with a
wooden dowel in contact on the back of the shoulders throughout each CMJ. A
linear position transducer (LPT) was attached to the wooden dowel to measure
PV and a portable force plate to measures of force. The subjects were instructed
to jump as high as possible. The best trial for each subject was used to assess the
relationship between IMP and PP, PV, and PF (during the concentric phase of the
jump). Pearson production moment correlation with 90% confidence intervals of
the log-transformed data was determined. Strength of the relationship was based
on: trivial, <0.10; small, ≤0.10-0.29; moderate, 0.30-0.49; large, 0.50-0.69; very
large, 0.70-0.89; and nearly perfect, ≥0.90. Results: The relationship between IMP
and PP, PV and PF were all deemed to be very large for the older adolescent
group. Further the relationship between IMP and PP and PF were very large for
the younger adolescent group. However, for the younger adolescent group, there
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
was only a small relationship between IMP and PV. Conclusion: Although, just a
correlation,these results demonstrated a very strong relationship exists between
IMP with PP, PV, and PF for older adolescent surfers. However, the only small
relationship between IMP and PV for young adolescent surfers may imply that
younger adolescent surfers may have a jump technique that is not conducive to
using an LPT to measure PV. A false PV for inexperienced or younger adolescents
may occur due to excessive forward trunk bend during the jump. Therefore, the PV
value for these younger adolescents could be indicative of the velocity their trunk
not the system mass velocity. This might explain the lack of relationship between
IMP and PV in the younger adolescent surfers. Practical Application: Strength
coaches and sports scientists should consider the implication of jump technique
when using an LPT. Specifically, the amount of trunk flexion should be observed
if an LPT is in use.
Poster: 57
COMPARISON OF MUSCLE RECRUITMENT DURING BENCH PRESS EXERCISE
WITH ELASTIC BANDS VS. A FIXED-BAR TREJECTORY
C. Capps1, J. Calatayud2, S. Borreani2, J. Colado2, D. Moya2, F. Martin2
1
Appalachian State University, 2University of Valencia
The push-up and bench press are traditional exercises normally used to strengthen
the trunk and upper extremities. Resistance training is commonly performed with
expensive and specific equipment whereas elastic bands may allow a feasible
alternative to performing resistance training at home. However, there is a lack of
evidence regarding muscle recruitment during push-ups with additional elastic
load and their possible comparison with the bench press. PURPOSE: The aim of
the study was to compare muscle activation of the pectoralis major and anterior
deltoid while performing 6RM push-ups with elastic bands and a 6RM bench
press in a Smith machine. METHODS: 38 physically fit and healthy male and
female subjects took part in a randomized, within-subject design study. Loads
were adjusted during push-ups with the addition of elastic bands, and during
the bench press with additional weight so that subjects could perform only 6
maximal repetitions (6RM). Different colors (gold, silver and/or blue) and length
of the elastic bands were adjusted to reach maximal effort. Each subject used
a standardized grip width (biacromial+50%), range and speed of movement. Correct body position was confirmed with a laser goniometer. The respective
6RM loads (bands or weights) were determined on a different day, prior to the
main testing sessions involving the electromyography. The order of the elastic
bands and bench press conditions were counter-balanced. The best of two
maximum voluntary isometric contractions (MVIC) for each muscle was evaluated
for normalization purposes. Pectoralis major (PEC) and Anterior deltoid (DELT)
muscular activities were recorded and the mean and peak root mean square
values were calculated. Surface electromyography activity was analyzed during
the entire 6 repetitions. All values, expressed as the mean and peak %MVIC of
both muscles were compared using a paired samples t-test. Significance level was
set at p≤0.05. RESULTS: No significant differences were found between both
conditions for PEC [mean: t(33)=0.093, p=0.927; peak: t(33)=-0.040, p=0.968]
and DELT [mean: t(36)=1.185, p=0.244; peak: t(36)=0.084, p=0.934]. Results are
reported in this study. CONCLUSIONS: Performing a 6RM set of push-ups with
elastic bands resulted in similar muscle activation to performing a 6RM set of
bench press in a Smith machine. PRACTICAL APPLICATIONS: Push-ups with
elastic bands are a feasible and cost-effective alternative to traditional bench
press exercise, especially in relatively untrained individuals. In the early stages
of a training program, subjects can benefit from this training modality and may
prefer the convenience to traditional equipment. Another application may be in
the elderly, and in either case, until strength levels increase to the point where
traditional exercises are warranted.
Poster: 58
MUSCULAR ACTIVATION DURING PUSH-UPS PERFORMED ON SUSPENSION
TRAINING DEVICES WITH DIFFERENT TYPES OF ANCHORING
T. Haines1, F. Martin2, S. Borreani2, J. Calatayud2, D. Moya2, J. Colado2
1
Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus
Femoris, Lumbar Erector Spinae and Gluteus Maximus during execution of 3
repetitions of the push-up exercise at low height, using two different suspension
devices. Surface electromyography was recorded and the average root mean
square values were calculated for each condition and muscular group. The
conditions were counter-balanced. The maximum isometric voluntary contraction
(MIVC) was evaluated for the normalization of the electromyographic signal. All
values, expressed as the % MIVC, were compared using a Student’s paired T-test
analysis. Significance level was set at p<0.05. RESULTS: Differences between
each condition are shown in this study. CONCLUSION: Push-ups performed with a
suspension device with one anchoring point induce significantly greater activation
in the Triceps Brachii and Upper Trapezius; however, push-ups performed with a
suspension device with two anchoring points induce significantly greater activation
in the Anterior Deltoid and Clavicular Pectoralis. PRACTICAL APPLICATIONS: The
dual anchoring point configuration appears to mimic the bench press better while
the single anchoring point configuration appears to necessitate more use of the
upper back musculature, which may be counterproductive to the training goals. These results could help to determine which type of suspension device should be
used depending on the primary training purpose.
Appalachian State University/Neuromuscular & Biomechanics Laboratory,
Department of Health, Leisure & Exercise Science, Boone, NC,
2
University of Valencia
Suspension devices for physical conditioning have increased the available tools
of the professionals that use devices to cause instability. Suspension devices
can anchor from a single point or from two points, and the effect on the body
may differ. PURPOSE: To compare agonist and lumbopelvic muscular activation
during push-ups performed on suspension training devices with different
anchoring points. METHODS: 29 physically fit and healthy subjects took part in
the investigation. Muscular activation was evaluated in Triceps Brachii, Upper
Poster: 59
THE USE OF ASYMMETRIES IN UNILATERAL LEG POWER FOR MOVEMENT
SCREENING IN FEMALE TEAM SPORT ATHLETES
R. G. Lockie1, A. B. Schultz1, T. M. Luczo2, S. P. Berry1, M. D. Jeffriess1,
S. J. Callaghan1, C. A. Jordan1
1
University of Newcastle/Exercise and Sport Science, 2California State
University Monterey Bay/Department of Kinesiology
Movement screens are commonly used to assess movement deficiencies in athletes.
The Functional Movement Screen (FMS) is comprised of 7 actions: deep squat
(DS), hurdle step (HS), in-line lunge (ILL), shoulder mobility, active straight-leg
raise (ASLR), trunk stability push-up (TSPU), and rotary stability. However, without
the requisite experience, the FMS is hard to administer. Multidirectional (vertical,
horizontal, lateral movement planes) unilateral jumps, and between-leg jump
asymmetries, are also used for screening. The relationship between an established
screening protocol such as the FMS, and unilateral jump asymmetries, has not
been investigated. PURPOSE: To determine the relationship between FMS scores
and leg power asymmetries as measured by unilateral vertical, standing broad and
lateral jump performance. METHODS: 14 female team sport athletes were tested
over 2 sessions. Subjects were assessed in the FMS by 2 exercise scientists in the
first session. The vertical, standing broad and lateral jump tests were completed in
the second session. Percentage between-leg asymmetries for each jump condition
were also calculated (powerful leg - weaker leg/powerful leg x 100). Subjects were
also split into 2 groups (lesser and greater asymmetry) depending on the jump
asymmetry that had the strongest relationship to the FMS. RESULTS: Spearman’s
correlation (r) analysis (p≤0.05) found significant relationships between the FMS
scores and jump asymmetries. A 1-way analysis of variance (p≤0.05) determined
between-group differences, and effect sizes (ES) were calculated. Unilateral
vertical jump asymmetry correlated with the right-leg ILL (r=-0.536), TSPU (r=0.615), and overall score (r=-0.551). Subjects were split into lesser (n=9) and greater
(n=5) vertical jump asymmetry groups. The TSPU had a significant between-group
difference (lesser=2.44±0.73; greater=1.40±0.89; ES=1.28). There were large, nonsignificant, effects for the DS (lesser=1.78±0.83; greater=1.00±0.00; ES=1.33), and
right-leg ILL (lesser=2.44±0.51; greater=2.00±0.00; ES=1.22). CONCLUSION: The
between-leg asymmetry in unilateral vertical jump performance had the strongest
relationships to selected scores within the FMS; the TSPU, right-leg ILL, and overall
score. When subjects were split into groups of lesser or greater vertical jump
asymmetry, there was a significant difference in the TSPU, and moderate-to-large
effects for the differences in DS, right-leg ILL, and overall score, with the lesser
group performing better each time. The relatively small sample for this study
may have contributed to only 1 significant between-group difference being found.
Nonetheless, as shown by relationships to the TSPU and ILL, and the betweengroup differences, athletes with lesser asymmetries possess a more stable trunk,
mobile hip, knee, and ankle joints, and appropriate muscle activity through the
entire body. PRACTICAL APPLICATIONS: This research provides further support
for the use of unilateral vertical jump performance for screening, particularly
when considering between-leg asymmetries. By comparing unilateral vertical
jump asymmetries to the FMS, coaches now have an indication of the mechanical
characteristics present in female team sport athletes with lesser between-leg
power asymmetries as measured by unilateral vertical jump performance. To
reduce leg power asymmetries, female team sport athletes require a stable core,
and must ensure balanced mobility and strength for both legs.
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
Poster: 60
THE RELATIONSHIP BETWEEN 1RM SQUAT, BODY FAT, AND POWER IN NCAA
DIVISION 1 FOOTBALL LINEMEN
B. H. Jacobson1
1
Oklahoma State University
Training for lower body strength and power consists of squats and power cleans
and is assessed by 1RMs and vertical jump distance (VJ). Studies involving soccer
have found notable correlations between max half squats and sprint performance
and VJ suggesting that squats may enhance lower body power. While power and
strength has received noteworthy attention, no studies have focused on D1 linemen.
PURPOSE: The aim of this study was to determine the association between 1RM
squat (SQ), (%F), and the VJ in offensive (OL) and defensive (DL) football linemen.
METHODS: Following IRB approval, data spanning a four-year period was collected
and analyzed. A total of 160 observations inclusive of body mass, height, %F, 1RM
squat, and VJ were compared. Descriptive means for OL and DL included: mass
131.7 kg (290.3 lbs.), height 191.1 cm (75.25 in)., 22.6% fat, 63.5 cm (25.0 in. VJ), and
232.1 kg (511.8 lb.) SQ. RESULTS: Based on correlational analysis, a weak relationship
existed between VJ and 1RM squat (r=0.10) and a negative relationship was found
between VJ and %F (-0.37). Additionally a significant relationship between body
mass and %F was found. Results yielded a stronger correlation between VJ and SQ
(r=53) following control for %F CONCLUSION: On the larger scale athlete, %F is a
compromising factor in power output as demonstrated by the VJ. Large athletes
with less fat tended to parallel results in the association between 1RM SQ and
VJ found in soccer players. PRACTICAL APPLICATIONS: The implication that %F
hinders power production and that lean muscle mass promotes power production
in extremely large athletes serves as further evidence that fat reduction should be
prioritized in the conditioning of OL and DL.
Poster: 61
EFFECT OF CAFFEINE ON POWER-DURATION RELATIONSHIP DURING
3-MIN ALL-OUT EXERCISE
C. Cheng1, W. Hsu2, M. Shih1, T. Chen1, C. Lee3
1
Department of Athletic Performance, National Taiwan Normal University,
Graduate Institute of Sports Training, Taipei Physical Education College,
3
Center for General Education, National Sun Yat-sen University
2
PURPOSE: The ergogenic effects of oral caffeine on aerobic and anaerobic
performance, which both are important elements for team sport athletes, remain
controversial. Caffeine may enhance excitation-contraction coupling stems by
decreasing plasma potassium (K+) concentration during prolonged exercise,
but not during high-intensity exercise. The 3-min all-out exercise test (3MT) has
been developed to simultaneously estimate critical power (CP) and the curvature
constant for severe exercise (W). Therefore, this study examines the effects of
acute caffeine ingestion on the 3MT performance and plasma ion concentrations
in basketball players. METHODS: Fifteen male Division I collegiate basketball
players (age, 20 ± 2 years; height, 188 ± 6 cm; weight, 84 ± 12 kg; VO2max, 52 ± 6
ml·kg-1·min-1) were recruited and completed 2 trials separated by at least 1 week:
caffeine (CAF, 6 mg·kg-1 of caffeine) and placebo (PL, identical number of capsules
containing cellulose) conditions. Visit one served as familiarization. During visit
two, subjects performed an incremental cycling test to determine the resistance of
3MT. During the following visits, subjects performed CAF or PL trial in a randomized
crossover design. One hour after ingesting capsules, subjects performed the 3MT
on a cycling ergometer to estimate the CP and W. Blood samples for sodium
(Na+), K+, pH, and lactate (La) concentrations were drawn at pre-test, 1 hour after
ingesting capsules, and 5-min after the 3MT. The oxygen uptake (VO2) and heart
rate (HR) were continuously measured during the 3MT. Paird-samples t tests and
repeated measures two-way analysis of variance (ANOVA) with Bonferroni posthoc tests were used to compare all variables between trials. RESULTS: The W in
CAF (13.4 ± 3.0 kJ) was significantly higher than that in PL (12.1 ± 2.7 kJ, p < 0.05).
No significant differences were found in CP (CAF vs. PL, 242 ± 37 vs. 244 ± 42 W),
peak and mean power, total work, and peak VO2 (CAF vs. PL, 48 ± 8 vs. 49 ± 6
ml·kg-1·min-1) between two trials. Peak HR in CAF (172 ± 7 bpm) was significantly
higher than that in PL (165 ± 8 bpm, p < 0.05). From the start to the end of the
3MT, the pH dropped from ~7.40 to ~7.17 (p < 0.05) without significant differences
between trials. Significant trial × time interaction was observed for the La. The La
concentration after 3MT in CAF (11.3 ± 2.6 mmol·L-1) was significantly higher than
that in PL (9.8 ± 1.8 mmol·L-1, p < 0.05). There was no significant interaction effect
for [Na+]. The [K+] at 1-h after ingesting caffeine was significantly lower than that
in PL (CAF vs. PL, 3.87 ± 0.22 vs. 3.99 ± 0.30 mmol·L-1, p < 0.05). CONCLUSIONS:
These results indicate that caffeine ingestion might not enhance CP; however,
it could prevent a rise in resting plasma [K+] and improve the work capacity
when power output exceeds the CP. The increases in the accumulation of La and
elevation of HR resulted from caffeine should also be considered during intense
exercise. PRACTICAL APPLICATIONS: Caffeine may affect the physiology of
excitation-contraction coupling, thus benefiting subsequent performance during
severe intensity exercise, although it does not appear to improve aerobic capacity.
ACKNOWLEDGEMENTS: This study was funded by “Aim for the Top University
Plan” of National Taiwan Normal University and the Ministry of Education, Taiwan.
Poster: 62
THE EFFECTS OF A PERSONAL OXYGEN SUPPLEMENT ON RECOVERY AND
COGNITIVE FUNCTION AFTER EXHAUSTIVE EXERCISE
D. Bellar1, E. Cory2, L. Judge3
1
University of Louisiana at Lafayette, 2University of Louisiana at Lafayette, La,
3
Ball State University, Muncie, IN
Personal oxygen supplements have recently been introduced to the ergogenics
marketplace and have yet to be evaluated for physiological or performance
based effects. PURPOSE: The purpose of this investigation was to examine the
effects a personal 90% oxygen supplement had on a participant’s recovery from
a run at 80% of VO2Max and post exercise cognitive performance. METHODS: The
participants for this blind, placebo controlled experiment were college students
ages 20 to 28, with a total of 11 females and 7 males tested (n=18). Participants
first underwent a VO2max assessment (45.8 ± 8.4mlO2/kg*min). Participants then
ran two separate trials at 80% of their previously established VO2Max to exhaustion. Psychomotor Vigilance Testing was performed before and after each trial for 5
minutes. Participants were randomly assigned an order of treatment (placebo
-compressed air, or oxygen supplement) that was administered immediately at
the exhaustion and 2 minutes into the cool-down. RESULTS: Repeated measures
Anovas were used to assess the variables of interest during the first 2 minutes
after exhaustion. Analysis of heart rate data did not result in any significant main
effects or treatment (F=0.321, p=0.582) or treatment by time interaction effects
(F=0.794, p=0.646). Mean Heart rate during recovery was 162.7 bpm ± 4.0 for the
oxygen treatment and 160.8 bpm ± 4.1 for the placebo. Analysis of VCO2 during
recovery resulted in similar findings as there were no significant main effects for
treatment (F=0.952, p=0.344) or interaction effects for treatment*time (F=0.595,
p=0.832). Results of the Psychomotor Vigilance Testing again did not reveal
any significant main effects for treatment (F=0.556, p=0.467) or treatment*time
interaction effects (F=0.501, p=0.489) for mean reaction time over the 5 minute
test. Similar results for main effect for treatment (F=0.403, p=0.535) and
treatment*time interaction (F=0.2634, p=0.125) were found when minor lapses
in attention were analyzed. CONCLUSION: The results of the study suggest that
personal oxygen supplements do not enhance exercise recovery or cognition
during exercise recovery as compared to placebo. PRACTICAL APPLICATIONS: Athletes, coaches, as well as recreational exercisers should be aware that personal,
supplemental oxygen does not appear to be an effective exercise recovery
strategy. ACKNOWLEDGEMENTS: The authors would like to acknowledge the
contribution of funding and supplies by Second Wind LLC to this research project.
Poster: 63
AN EXAMINATION OF THE STRETCHING PRACTICES OF DIVISION I, II, AND III
COLLEGE FOOTBALL PROGRAMS IN THE UNITED STATES
E. Wanless1, L. W. Judge1, D. Bellar2, D. Pierce3,
B. Craig4, D. Lee3, C. Ethredge5
Ball State University/School of PE, Sport, and Exercise Science, Muncie, IN,
2
University of Louisiana at Lafayette, 3School of Physical Education, Sport
and Exercise Science, Ball State University, 4Ball State University/Human
Performance Laboratory, Muncie, IN, 5University of Louisiana at Lafayette, La
1
Research pertaining to pre-activity warm-up and stretching and post-activity
stretching has evolved over the past few decades. PURPOSE: The purpose of this
study was to examine the pre and post-activity stretching practices of Division I, II,
and III football programs to determine whether stretching practices are influenced
by divisional status and certification. METHODS: A 31-item survey instrument was
developed and used to collect data from 103 males and one female coach ranging
in age from 24 to 67 years (M = 42.59, SD =9.47). The questionnaire was designed
to gather demographic, professional, and educational information, as well as
specific usage pre- and post- stretching by the coaches. Results were initially
computed using all responses collectively to produce descriptive results for the
whole sample. Subsequently, items of interest were analyzed for differences by
key demographic variables (ie. age, division, and certification) and applicable
frequency counts were compared statistically via Pearson’s chi-square and
Kruskal-Wallis analysis in order to assess potential differences. Particular items
of interest included CSCS certification. Significance was set a priori to alpha < .05
for all analyses, and all statistical analyses were performed using SPSS version
NSCA National Conference & Exhibition Abstracts
PODIUM & POSTER PRESENTATIONS | JULY 10 – 13, 2013
20.0. RESULTS: Coaches typically prescribed a combination of static and dynamic
stretching activities (n=57) or exclusively dynamic stretching activities (n=45)
prior to practice or games. The results of the Pearson’s Chi Square analysis
demonstrated significant differences in the answers to three questions of interest
based upon the CSCS certification status of the individual. The majority (90.9%) of
non-CSCS certified coaches strongly agree (p < 0.05) that post-activity flexibility
helps to improve performance. The overall responses were demonstrated to be
significantly different (2 = 8.851, p < 0.05) likely driven by the higher percentages
of non-certified coaches that responded with strongly agree or agree. Significant
differences in responses to flexibility preventing injuries were reported by CSCS
certification status (2 = 16.924, p = 0.01). The majority of the non-CSCS certified
individuals (p < 0.05) reported strongly agree (53.2%) whereas among CSCS
certified individuals the most frequent answer was undecided (36%). KruskalWallis analysis revealed the length of the pre-activity flexibility is influenced by
divisional level (2 =6.276, p = 0.043). Division III coaches were the least likely to
use the shorter stretching time of less than ten minutes compared to Division I and
II coaches. CONCLUSION: The results of this study indicate that divisional status
and certification may influence how well research guidelines are followed. Further
research is needed to delineate how these factors affect coaching decisions.
PRACTICAL APPLICATIONS: The results of this study demonstrate the necessity
for football coaches to re-evaluate their methods, perhaps aligning them with the
existing research.
Poster: 64
DIFFERENCES IN LOADED-SLED SPRINT TIMES BETWEEN FEMALE
VOLLEYBALL AND SOFTBALL PLAYERS
M. A. Waller1, T. Robinson1, M. Gersick1, D. Holman1
1
Adams State University
INTRODUCTION: The purpose of the study was to investigate if differences
existed between two female power sports in regards to loaded-sled sprint times.
Resisted sprints have been studied using towing devices (e.g. parachute) but
there is a paucity of information related to the effects of sled pushing on athletic
performance. The current study examined if any difference may exist between
two female power sports to determine if future studies would need to establish
specific muscular force-time characteristics criteria for participant selection to
minimize heterogeneity. METHODS Participants were Division II female power
athletes (Volleyball (VB) n = 9; Softball (SB) n = 5, Body-mass = 70.71 ± 5.39 kg,
Height = 170.28 ± 6.41 cm, Body-fat % = 17.47 ± 3.62) who were tested during
their off-season training phase. Participants were tested each week on the same
day and time for 7 consecutive weeks and allowed to miss 2 consecutive testing
sessions before being removed as a participant. Body mass was measured using a
digital scale, while body-fat % was measured using skinfold calipers. Participants
had previously used the push-sled during their strength and conditioning program
so no familiarization session was used. Seven sprint conditions were used, with
each condition having a distance of 18.8 m, with 35 seconds recovery between 6
sprinting bouts. Participants performed sprints (control), sprints pushing sled-only
(29.48 kg), and sprints pushing the sled with an additional 10 kg, 15 kg, 20 kg, 35
kg, & 50 kg. Timing was completed by the same researcher using a hand-held stop
watch, which was started on the participant’s first movement and stopped upon
covering the specified distance. All testing was conducted in an indoor field house
on an rubberized flooring. RESULTS No statistically significant differences were
seen between the two sports peak sprint times. Cronbach’s alpha demonstrated
reliability (α = 0.82). DISCUSSION No statistical differences were seen between
female VB and SB athletes, although the SB athletes demonstrated practically
faster sprint times with sprinting conditions ≥ 20 kg loads. These observable
differences may be indicative of the SB athletes incorporating sprints of greater
than 10 m in their strength and conditioning program. The results suggest that
future sled-pushing studies may utilize both groups in assessing the effects of
sled pushing on sprint performance. PRACTIAL APPLICATION Sled-pushing loads
during strength and conditioning programs do not need to be adjusted for the
respective sports between female volleyball or softball players.
Poster: 65
THERMAL STRESS FOR WOMEN’S ISLAMIC ATHLETIC CLOTHING
IN VARIOUS AMBIENT ENVIRONMENTS
K. Allen1, J. Davis1, M. Laurent2, P. Bishop3, M. Green3, N. Stolworthy1,
T. Welch4, M. Nevett1
1
University of Montevallo, 2Bowling Green State University,
3
University of Alabama, 4University of South Florida
PURPOSE: Traditional Islamic laws and customs prohibit Muslim women from
wearing revealing sports attire. Some countries have allowed Muslim women
to participate in sports but women must adhere to Islamic laws and remain
covered during competition. The impact of Islamic clothing covering much of the
surface area of the body on heat stress is unclear. This study examined rectal
temperature (Trec), mean skin temperature (Tsk), and perceptual response of
females wearing Islamic athletic clothing (IC) vs. traditional soccer uniform (SC).
METHODS: Female volunteers (N = 8) completed a treadmill VO2peak test and then,
in a randomized, counter-balanced order, four intermittent running bouts (45
min total) at 31.1°C and 35.5°C in IC and SC. Immediately after the intermittent
running bouts participants ran at 85%VO2peak until volitional exhaustion or core
temperature termination. Session RPE (SRPE) and thermal sensation (TS) were
recorded following each bout. RESULTS: A MANOVA reveals a significant main
effect for heat (p=0.01) and clothing condition (p=0.01). Univariate post-hoc
measures for heat condition show significantly higher TS (6.6 vs. 6.2; p=.02),
weight lost (0.94 vs 0.82 kg; p=0.02) with lower time to exhaustion (TTE)
(49:10 vs. 52:17min; p<0.01) during the 35.5°C vs 31.1°C condition. There were no
significant differences found in the change of mean Trec (p=0.41) or Tsk (p=0.79)
throughout the bout, or SRPE (p=0.09) between heat conditions. With respect to
clothing, post-hoc measures show significantly higher SRPE (7.6 vs. 6.8; p = 0.01),
TS (6.5 vs. 6.2; p=0.02) and weight lost (0.94 vs 0.82 kg; p=0.01) in IC vs. SC. There were no significant differences in change of Trec (p=0.85), mean Tsk change
(p=0.63) throughout the bout or TTE (p=0.12) between IC and SC. CONCLUSION:
IC clothing appears to have no detrimental effects on heat strain (Trec, Tsk)
compared to a traditional soccer uniform during exercise. IC did, however, produce
greater subjective discomfort and greater sweat rate despite no difference in
physiological variables. PRACTICAL APPLICATION: Within the context of this
study it appears Muslim garb does not offer a greater threat to thermal balance
compared to traditional soccer clothing. ACKNOWLEDGEMENTS: No sources of
funding were used to assist in the preparation of this abstract. The authors have
no conflicts of interest that are directly relevant to the content in this abstract.
NSCA National Conference & Exhibition Abstracts