Effective Training Modalities, Olympic Weightlifting, Plyometrics & Traditional Resistance Training in Children David Behm PhD
School of Human Kinetics and Recreation Memorial University of Newfoundland
St. John’s, Newfoundland, Canada
Scientific Acceptance of Resistance Training for Children
American College of Sports Medicine American Academy of Pediatrics Australian Strength and Conditioning Association British Assoc. of Sport / Exercise Science Canadian Society for Exercise Physiology National Strength and Conditioning Association
Sampling of Review articles:
Faigenbaum 2000, Falk and Tenebaum 1996, Falk and Eliakim 2003, Blimkie 1993, Sale 1989 Effects of Traditional Resistance Training with Children and Adolescents
Summary of the effects of resistance training (RT) in children and adolescents.
Effect
Muscle
Strength
Children
+++
Adolescents
Sample References
+++
Blimkie et al. 1989, 1996;
Christou et al. 2006;
Faigenbaum et al. 1993, 1996a,
2001, 2002, 2005b;
Fukunaga et al. 1992;
Lillegard et al. 1997;
Nichols et al. 2001;
Ozmun et al. 1994;
Pfeiffer & Francis 1986;
Pikosky et al. 2002;
Ramsay et al. 1990;
Sadres et al. 2001;
Sailors & Berg 1987;
Siegal et al. 1989;
Tsolakis et al. 2004;
Weltman et al. 1986
Notes
Smaller absolute strength
gains in children
compared with adults but
comparable relative gains
Table 1: Behm et al. 2008
Effects of Traditional Resistance Training in Children and Adolescents
Effect
Children Adolescents
Sample References
Notes
Muscle
Power
?
+
Christou et al. 2006;
Small if any changes in
Faigenbaum et al. 1993, 1996a, children; limited data in
2002, 2005b;
adolescents
Lillegard et al. 1997;
Weltman et al. 1986
Muscular
Endurance
++
+
Faigenbaum et al. 1999, 2001,
2005b;
Ramsay et al. 1990;
Sailors & Berg 1987
Limited data in
adolescents
Table 1: Behm et al. 2008
Objectives
• 1. What is a logical training sequence to implement power training with children?
• 2. Do plyometrics and Olympic weight lifting increase power or explosive strength in children?
• 3. Is it safe to employ power resistance exercises with children?
Warm‐up Goal: Excitation
Static stretching (SS) can depress the system resulting in impairments in muscle activation, force, power, sprint, reaction and movement time, balance
(Behm and Chaouachi 2011, Chaouachi et al. 2008, Behm and Kibele 2007, Behm et al. 2001, 2004, 2006, Power et al. 2004, Young and Behm 2002)
Static stretching (SS) impairs performance even in children: ↓ sprint time with 13-15 year boys
(Chaouachi et al. 2008)
SS with 11 yr. old children; ↓ vertical jump and
shuttle run (Faigenbaum et al. 2005)
Effect of Trained State on Static Stretch Impairments 0
Trained Jump
Untrained Jump
Trained Force
Untrained Force
‐2
% Change
‐4
‐6
10 studies
15 studies
‐8
‐10
31 studies
‐12
53 studies
Behm and Chaouachi 2011
Behm and Chaouachi 2011: reported average 5% deficit with static stretching
Kay and Blazevich 2012: reported average 7.5% deficit with static stretching
2012 Olympics: Usain Bolt: 9.63 seconds
Gerald Phiri of Zambia: 10.11 seconds
Effect of Static Stretching Duration on Force
0
0‐30s
30‐60s
60‐90s
>90s
% Change in Force / Torque
‐1
‐2
5 studies
4 studies
‐3
‐4
‐5
13 studies
‐6
Time(sec)
61 studies
Behm and Chaouachi 2011
StaticStretchingDuration:Behm,Blazevich,KayandMcHugh2015
FigureX:Typicalwarm‐upsequenceversusresearchstudylimitations.
Aerobic Warm‐up
5‐15 min
Many studiesbut
notallstudies
includeaprior
aerobicactivity
Example:
36/123SSstudies
didnotinclude
prioraerobic
activity
Stretching
(SS,DS,PNFor
combination)
Sport Specific
Activities
5‐15 min
Many of the earlier
studiesemployed
unrealisticallylong
stretching
durations
Example:
Fowlesetal.2000
30mincalfstretch
Behmetal.2001
20minquadriceps
stretching
5‐15 min
Most studies do
notincludepost‐
stretching,sport
specificactivities.
Averagetesttime
post‐SS,DSand
PNFare3.2,5.3
and4.1min
respectively.
Manystudiestest
immediatelypost‐
stretching.
Return to room for
equipment,tactical
andother
adjustments
5‐10 min
Mean changes and
effectsizeswhen
testedlessthan5
minfollowing
stretching
SS3.7%,ES=0.25
Small%andES
PNF5%,ES=0.13
Small%andtrivialES
DS1.3%,ES=0.43
Small%and
moderateES
Return to field,
court,icesurface
orothervenue
Startcompetition
5 min
Performance
decrements
elicitedbySSand
PNFusually
resolvewithin15‐
30min
Dynamic stretching and activities can excite the system resulting in facilitation of performance (Youth literature: Faigenbaum et al. 2005a; 2006a; 2006b; Siatras et al. 2003)
(Adult literature: Behm and Chaouachi 2011, Curry et al. 2009, Hough et al. 2009, Herder et al. 2008, Manoel et al. 2008, MacMillan et al. 2006)
Dynamic Stretching
%changeEffectSizes
All studies
Strength
Power/speed
Isometric
Concentric
Eccentric
+1.3% (+0.3, +2.2)
+1.1% (+0.9, +3.1)
+1.9% (+0.9, +2.8)
+3.0% (+0.4, +5.7)
+0.4% (-2.4, +3.2)
-1.2% (-18.6, +16.1)
0.33 (0.20, 0.46)
0.35 (0.86, 1.35)
0.25 (0.15, 0.36)
0.27 (-0.06, 0.61)
0.43 (0.11, 0.75)
2.46 (-1.04, 5.95)
Summaryof~50DSstudies:Behm,Blazevich,KayandMcHugh.2015
Effect of dynamic stretching duration on force and power
1 measure
4 measures
10
% Change in Force/Power
8
6
2 measures
6 measures
4
2
0
0‐30s
30‐60s
60‐90s
>90s
‐2
Behm and Chaouachi 2011
Optimal volume of DS
“10‐15 repetitions” or “10 yards‐20 meters” x “1‐2 sets” Stretching Recommendations
When a typical pre‐event warm‐up is completed a. initial aerobic activity to raise core temperature 1‐2°C, b. stretching component, c. 5‐15 min of task‐ or activity‐specific dynamic activities
The benefits of SS and PNF stretching for augmented ROM and reduced injury risk at least balance, or may outweigh, any possible cost of (trivial) performance decrements. Performance impairments typically not apparent when stretching precedes a 5‐15 min dynamic warm‐up
Dynamic stretching and sport specific dynamic activities should always be included in a warm‐up.
Power Resistance Training (RT) Progressions
Balance and coordination are not fully developed in children (Payne and Isaacs 2005), balance training may be particularly beneficial for reducing the risk of injury while performing RT, particularly to the lower back. Include specific exercises that require balance and coordination.
Many studies have shown ↓ force/strength, power, ROM
with instability with adults (Behm and Colado 2012)
“Old Man Strength”
• When competing; who gets the ball or puck between a typical • 27 year old, 80 kg athlete vs. • 17 year old, 80 kg athlete • (with similar lean body mass)?
• Why?
• Better balance, stability and coordination
Can’t Shoot A Cannon from a Canoe
Effect of Balance Training on
Balance
Young Adults
18studies
Seniors
17studies
Youth
8studies
Subject
Number
% change
Effect Size
N=20.311
Training
Duration
(weeks)
6.22.1
25.7%17.4
1.180.92
N=57.155.7
12.39.5
25.9%29.5
0.840.92
N=28.221.7
7.03.0
20.1%20.5
1.10.91
Youth balance training effects
•
•
•
•
•
•
•
Granacher et al. 2010
4‐week balance‐training program integrated into high school PE lessons.
Measured postural sway, jump height, and maximal isometric leg extension force.
Balance training improved postural control, jumping height and enhanced RFD. Granacher et al. 2011
Grade 1 students
Balance training resulted in tendencies in terms of small to medium interaction effects yet not statistically significant improvements in postural sway, PF force and jump height
Immaturity of the postural control system and deficits in attentional focus during practice of balance exercises could be responsible for the nonsignificant findings. Static Balance
Kean et al. 2006
5 weeks of balance training with adults with no jump or strength training increased vertical jump by 9%
Static balance improved by 33%
Improve balance : improve
strength/performance at any
age!
How is an increase in vertical jump possible with only balance training?
Decrease the sway and direct the forces in a more optimal direction
Balance and Stability
A positive correlation (0.65) between maximum hockey skating speed and static balance test in
hockey players under 17 years reported
(Behm et al. 2004)
Balance only training studies report increases in performance
Behm and Colado 2012
Effect of Instability Resistance
Training on Performance
Need studies to examine instability resistance training with children
Increased Core Activation with
Instability Resistance Training
Increased Core Activation with
Instability Resistance Training
Balance Training Advantages
1.
2.
3.
4.
5.
Use of body weight as a resistance
Balance and stability challenges
High core / trunk activation with lower loads
Instability training specificity
Variety and fun
Resistance Training Progressions
• Gradually progress to more advanced movements that enhance strength and power production.
• Traditional Closed Kinetic Chain Resistance Training
• Plyometrics: bounding, hopping, jumping
• Olympic style lifting
Plyometrics
• Essentials of Strength and Conditioning textbook (NSCA) stated that an individual should be able to leg press 1.5 times body weight before starting plyometrics.
• Common European definition of plyometrics refers to high intensity drop jumps.
• Narrow definition of plyometrics!
Plyometrics
Youth can train with plyometrics if amplitude and volume are low
Simple games like skipping are plyometric in nature
Can start at any age Pre‐pubertals should not engage in intensive depth‐
jumping
Plyometrics
• Begin plyometric training with less intense drills (e.g., double‐leg jumps) and progress to more advanced drills (e.g., single leg hops) as competence and confidence improves. • Studies indicate that few repetitions (i.e., ≤ 10) are needed for training‐induced gains in plyometric performance (Lephart et al. 2005; Myer et al. 2005; Matavulj et al. 2001).
• Early emphasis on positioning and landing
Emphasis on landing technique for performance and injury prevention
Ballerinas have significantly less knee injuries than similar jumping‐related sports such as netball (Leonie Otago: personal correspondence)
• Johnson et al. (2011 JSCR) report in their meta‐analysis that plyometric training with children had large positive effects on jumping and running performance with further evidence to suggest associated improvements in kicking distance balance and agility. • However, there has been some reticence to apply these explosive training activities with children. • The CSEP position stand recommends that plyometric training can be safe and effective for enhancing muscle power in children (Behm et al. 2008). • Studies employing plyometric training programs for youth reported improvements in vertical jump height (Faigenbaum and Keiper 2007), rebound jump height (Meylan and Malatesta 2004 JSCR) and running speed (Kotzamanadis 2006 JSCR). • Behringer et al.’s (2011) meta‐analysis on the transfer of resistance training gains to motor performance in youth reported the highest effect sizes with a combination of plyometric and traditional resistance training programs. Olympic Lifts
Training Specificity:
Youth need to develop strength and power from an athletic position
Velocity Specificity based on the intent to contract explosively (Behm and Sale 1993)
Training Specificity
Athletic Position
What sport is Anna playing?
Basketball?
Volleyball?
Hockey?
Football?
Olympic Style lifting
• Olympic‐style lifts involve a more complex neural activation pattern and therefore participants need to learn how to perform these lifts early in the workout with a relatively light load (e.g., wooden dowel or unloaded barbell) in order to develop coordination and skill technique without undue fatigue. Olympic Weight Lifting (OWL)
• Ebada (2011) instituted a 3‐month children (mean of 13.2 years) OWL training program resulting in an average 4.9% increase in 9 strength tests (e.g. snatch, clean, squats). • An 8‐week training program compared OWL and traditional closed link strength exercise (e.g. squats, dead lifts) training with high school males averaging 15.9 years (Channel and Barfield 2008 JSCR). OWL training exhibited a modest advantage over conventional power training for vertical jump performance.
Future World Champion?
Olympic weightlifting and plyometric training with children provides similar or greater performance improvements than traditional resistance training
Chaouachi, et al. 2014 JSCR
•
•
•
•
•
63 children (10‐12 years)
randomly allocated to a 12‐week control, OWL, plyometric or traditional Resistance Training program
Pre‐ and post‐training tests included BMI, sum of skinfolds, countermovement jump (CMJ), horizontal jump, balance, 5 and 20 m sprint times, isokinetic force and power at 600.s‐1 and 3000.s‐1. Magnitude‐based inferences were used to analyze the likelihood of an effect having a standardized effect size exceeding 0.20.
Less than 0.2 = trivial effects
• The possibility of an extended learning period for OWL training might attenuate the strength or power gains compared to traditional RT over the same duration.
Olympic weightlifting and plyometric training with children provides similar or greater performance improvements than traditional resistance training
Chaouachi et al. 2014 JSCR
OWL
Effect Sizes > 0.8 = strong magnitude of change
OWL
Olympic weightlifting and plyometric training with children provides similar or greater performance improvements than traditional resistance training
Chaouachi, et al. 2014 JSCR
OWL
OWL
Effect Sizes > 0.8 = strong magnitude of change
Olympic weightlifting and plyometric training with children provides similar or greater performance improvements than traditional resistance training
Chaouachi, et al. 2014 JSCR
OWL
Effect Sizes > 0.8 = strong magnitude of change
Is power training safe for children?
Is power training too intense for youth?
Falk and Dotan (2006) reported that children recover faster from high intensity exercise due to their lower maximal power output and thus have lower stress levels to recover from.
10 boys: 9.7  0.94 years vs. 10 men: 25.7  2.4 years 2 randomized experimental sessions, which included either A) 3 sets of high repetition maximum (High RM) (17 repetitions of knee extensions)
B) 3 sets of low repetition maximum (Low RM), (7 repetitions of knee extensions)
(tempo of 1s concentric and 1s eccentric contraction controlled by a metronome) 1min rest interval between sets. The children fatigued but not to the same extent as the adults.
Murphy et al. 2014 EJAP
Children’s EMG normalized to MVC does not sig change during the fatigue protocols
Murphy et al. 2014 EJAP
• Although the fatigue incurred by the children could not be explained by changes in peripheral nor central mechanisms, the increased antagonistic activity (hamstrings) suggested that the fatigue was more likely to be a result of muscle coordination difficulties (increased co‐contractions). Murphy et al. 2014 • Faigenbaum et al. (1999) states that in some countries, children learn Olympic lifts as early as 8 years, but resistance is not added to the bar until they have developed the proper coordination. Summary
• Resistance Training for children/adolescents is beneficial for health and performance
• Warm‐up should involve <60s of static stretching per muscle and >90s of dynamic stretching per muscle and activities to excite the system
• Due to an immature system, balance training without resistance should be the first step
Summary
• Balance training without resistance can be followed instability resistance training with relatively lower loads
• Traditional closed kinetic chain exercises can be implemented to further increase strength and still provide balance challenges
• Plyometrics and Olympic lifts provide the greatest balance and power challenges.
Summary
• Introduce proper technique for plyometrics and Olympic lifts for athletes to attain training specific form and power (athletic position)
• Introduce low amplitude plyometrics to improve reactive strength
• Emphasize variety and FUN!!
Thank‐you! Kiitos!