Comparison of a YOYO Intermittent Recovery Level 1 test
and VO2 m a x test as a determination of training speeds and
evaluation of aerobic fitness
By
Nathan Heaney
A thesis submitted in partial fulfilment of the requirement for the Bachelor of Exercise
Science (Honours)
Australian Catholic University
St Patrick’s Campus
Melbourne, Victoria
October, 2012
i
STATEMENT OF SOURCES
This thesis contains no material published elsewhere or extracted in whole or in part from
a thesis which I have qualified for or have been awarded another degree.
No other person’s work has been used without due acknowledgement in the main text of
the thesis.
This thesis has not been submitted for the award of any other degree or diploma in any
other tertiary education.
All research procedures reported in this thesis received the approval from the Australian
Catholic University Human Research Ethics Committee.
…………………………….
………………………..
Nathan Heaney
Date
ii
STUDENT CERTIFICATION
Australian Catholic University
School of Exercise Science
I am the author of this thesis entitled
Comparison of YOYO Intermittent Recovery Level 1 test and VO2 max test as
determination of training speeds and evaluation of aerobic power
Submitted for the degree
Bachelor of Exercise Science (Honours)
and I agree to grant the School of Exercise Science permission to make this thesis
available for consultation, loan or photocopying, in whole or in part.
…………………………….
………………………..
Nathan Heaney
Date
iii
ACKNOWLEDGEMENTS
The author wishes to acknowledge and thank the following people for their valued
contribution to the study:
Dr Morgan Williams - You were the first to offer guidance and structure to a fledgling
University student and for that, I am forever grateful. Not only did you help point me in
the right direction as to a viable career path, but you also displayed incredible patience
during this long and often arduous process.
Dr Justin Kemp – You have also been an unwavering source of support, guidance and
feedback. I can say without hesitation that this thesis would still be on my ‘to do’ list if it
wasn’t for your input and remarkable turn around time, despite what would be, at times, a
seemingly endless workload.
I would also like to thank the Victorian Institute of Sport for being so understanding and
supportive during this process. In particular, I’d like to thank Dr Harry Brennan for
creating a work place that is conducive for professional development and, Ben Willey for
providing the impetus to rid myself of this thesis.
Australian Catholic University – Thank you for your on-going support.
Melbourne Vixens & Victorian Fury – Thank you for allowing me access to athletes for
the purposes of this study.
Lastly, I would like to thank my girlfriend, Kara, for being so understanding and
encouraging during this process. It helped immensely to know that I had your full support
whilst trying to close this chapter in my life.
iv
TABLE OF CONTENTS
STATEMENT OF SOURCES…………………………………………………………... ii
STATEMENT CERTIFICATION……………………………………………………… iii
ACKNOWLEDGEMENTS…..……………………………………………………........ iv
LIST OF APPENDICES……………………………………………………………….. vii
LIST OF TABLES……………………………………………………………….......... viii
LIST OF FIGURES………………………………………………………………........... ix
CHAPTER 1. LITERATURE REVIEW……………………………………………....1
1. The aerobic energy system in netball: physical performance and capacities....2
2. Measurement of Aerobic Fitness……………………………………………...6
2.1 YOYO Intermittent Recovery Tests……………………………………....9
3. Physiological Adaptations to Aerobic Energy System Conditioning………..11
3.1 Velocity at VO2 max ( vVO2 max )……………………………………………16
3.2 Maximal Aerobic Speed (MAS)…………………………………………17
3.3 Determining MAS or vVO2 max to prescribe HIIT………………………..17
4. Using MAS or vVO2 max to prescribe HIIT…………………………………….21
4.1 Benefits of MAS and vVO2 max to administer sessions…………………...25
5. Aims of the Study……………………………………………………………..26
6. References……………………………………………………………………..27
v
CHAPTER 2. JOURNAL SUBMISSION………………………………………….....35
Abstract…………………………………………………………………………..37
Introduction………………………………………………………………………39
Methods…………………………………………………………………………..43
Subjects…………………………………………………………………..43
Methodology……………………………………………………………..37
YOYO IR1 testing protocol...……………………………………………44
VO2 max testing protocol…………………………………………………..45
Statistical Analysis……………………………………………………….46
Results……………………………………………………………………………47
Discussion………………………………………………………………………..50
Practical Applications……………………………………………………………53
References………………………………………………………………………..55
CHAPTER 3. EXTENDED METHODOLOGY………………………………...........57
Participants……………………………………………………………………….58
Procedures………………………………………………………………………..58
YOYO IR1 testing protocol……………………………………………………...59
VO2 max testing protocol…………………………………………………………..61
Statistical Analysis……………………………………………………………….63
References………………………………………………………………………..64
vi
LIST OF APPENDICES
Appendix 1. Letter of invitation to the participants….…………………………………67
Appendix 2. Consent form……………………….……………………………………..70
Appendix 3. Assent form……………………….……………………………………….72
Appendix 4. Letter of Invitation to Coach / Organisation………………………………76
vii
LIST OF TABLES
CHAPTER 2: JOURNAL SUBMISSION
Table 1. VO2 max , YOYO-IR1 distance and training speeds for the netball squad
(and for different positions) obtained from the YOYO-IR1 and the VO2 max
test………………………………………………………………………………..49
Table 2. Pearson’s correlation coefficient for training speeds………..…………50
CHAPTER 3: EXTENDED METHODOLOGY
Table 1. Number of shuttles, speed and distance completed for each YOYO IR1
level……………………………………………………………………………..60
viii
LIST OF FIGURES
CHAPTER 2: JOURNAL SUBMISSION
Figure 1. Linear regression of YOYO-IR1 total distance and VO2max for the
entire squad of female Netballers………………………………………………48
ix
LITERATURE REVIEW
1
1. The aerobic energy system in netball: physical performance and capacities
The aerobic energy system underpins netball performance as it can positively influence a
netballer’s physical activity profile in their pursuit to meet the wide ranging technical and
physical demands of netball competition. Activity profiles are intermittent, where
netballers are required to perform various high intensity sport specific movements, such
as, sprinting, jumping, pivoting, changing direction and intercepting, all of which are
interspersed by low intensity activity. In order to sustain performance throughout the
match, netballers are required to recover quickly from repeated high intensity efforts and,
therefore, must possess a well-developed aerobic energy system (Bishop; Edge &
Goodman, 2004; Bishop, Lawrence & Spencer, 2003; Tomlin & Wegner, 2001). Often
these high intensity sport specific movements are considered game-defining and, as such,
are critically important to the competition outcome (Dupont, Akakpo & Berthoin, 2004;
Helgerud, Engen, Wisloff & Hoff, 2001; Krustrup et al, 2003). Conversely, the
consequences of an inability to recover effectively between high intensity activity can
result in poor decision making (Royal, Farrow, Mujika & Halson, 2006), an increased
risk of injury and, ultimately, an inability to perform the desired actions (Borotikar,
Newcomer, Koppes & McLean, 2008).
Average game intensity varies depending on the sport, but for most team sports intensity
falls between 80 and 90% heart rate maximum, which equates to 70-80% maximal
oxygen uptake (Bangsbo, Mohr & Krustrup, 2006; Dellal et al, 2008; Helgerud et al,
2001). Currently, data describing specific physiological and physical demands of netball
2
are not widely available. Of the studies to date that have reported physical activity of
netballers, all have limitations and none are as robust as those from sports such as soccer
(Bangsbo, Mohr & Krustrup, 2006; Dupont, Akakpo & Berthoin, 2004). One of the first
studies describing movement patterns of competitive netball was by Otago (1983). This
particular study measured the physical activity profile of elite netballers and as expected,
revealed that there were differences between playing positions. Otago (1983) also
reported that the average work to rest ratio (W:R) for all positions was constant at 1:3,
however, the method in which the data was collected limited the usefulness of the
findings. Specifically, television coverage was used and, as a result, activity was difficult
to record when the players were not in the field of view (i.e. not near the ball). In
addition, not all players were able to be monitored throughout the entirety of the match
and, lastly, the data were obtained from a limited number of matches. Steele and Chad
(1992) identified the weaknesses in the aforementioned study by Otago and aimed to
address some of them. Data were captured for the entire court, which enabled the
researchers to better identify the movement patterns of different netball positions. As
anticipated, differences were observed by playing position with the goal keeper (GK) and
goal shooter (GS) spending the most time standing and the least time walking, jogging
and running. Conversely, centres or mid-courters spent less time standing and walking
and a greater percentage of time jogging and sprinting. Only four players per position
were analysed and, therefore, the findings of the study were still limited. Another time
motion analysis study of netball was conducted by Loughran and O’Donoghue (1999);
however, it differed from those previously mentioned as it used audio recordings to
determine work rate. The outcome was similar to the W:R findings of Otago (1983). This
3
study was also able to reveal how often netballers are required to perform different high
intensity activities throughout competition, thus highlighting the intensity of netball
competition. However, once again there were limitations with the methodology, as the
audio recordings were verbally coded into a computer system and different observers
were used to analyse different players, potentially leading to greater variability in the
results. Lastly, unlike the aforementioned studies which used elite level netballers, the
netballers used were of recreational standard.
More recently, a time motion analysis study was conducted by Davidson & Trewartha
(2008) to ascertain the physiological demands of netball. Six players, from the English
super league were analysed. The players were categorised into the following positional
groups: Centre, Goal Shooter or Goal Keeper. Each of the players were filmed
individually for the full 60 minute match and each individual’s movement was coded into
six different categories – standing, walking, jogging, running, sprinting and shuffling.
The coding was done retrospectively using the Sportscode software. From the coding
results, they established the W:R for three contrasting positions, whilst also establishing
the frequency, duration and percentage of match time spent performing each activity.
Unsurprisingly, the centre players had a significantly higher W:R ratio (1:1.9) than both
the goal shooters (1:4.5) and goal keepers (1:2.9). The centre players also recorded a
significantly higher total distance covered in a match (7984 ± 767 m) when compared to
the goal shooters (4210 ± 477 m) and goal keepers (4283 ± 261 m). However, some
caution should be shown when looking at the total distance covered, as the total distance
is predicted based on the relationship between time, speed and distance. This is listed as a
4
limitation of the study by the authors as the calculation requires the assumption that the
velocity of the player remains constant throughout the movement. Another limitation is
the use of average player speeds where it was not possible to obtain their individual
speeds. Both of these limitations could potentially lead to inaccuracies in the total
distance covered data.
Whilst time motion analysis data do provide a good overview of the physiological
demands of competitive netball, the abovementioned study by Davidson & Trewartha
(2008) did not provide any heart rate or oxygen consumption data. Thus, it is difficult to
determine the exact physiological demands and requirements for competitive netball. In
an attempt to get a better understanding of the exact physiological demands of
competitive netball, Kennedy, Appleby and Piggot (2011) presented heart rate data from
the elite Trans-Tasman netball competition. Heart rate (HR) data were collected across 44
quarters (or 11 matches) and six different positions. During competition, HR was
categorised as two zones; under 85% max heart rate (MHR) or above 85% MHR. Playing
positions were grouped into circle (goal keeper, goal shooter), GD (goal defense) and
centre court (wing defense, centre and wing attack). The percentage time above 85%
MHR was highest for GD (87%) and CC (82%) whilst 70% was recorded for the circle
players. These results are in line with previous literature (Davidson & Trewartha, 2008;
Loughran & O’Donoghue, 1999), and most likely stem from the fact that there is greater
court coverage for these positions.
5
Similar to the derived physical characteristics from time motion analysis studies, large
discrepancies exist in reported physiological profiles for female team sport athletes when
compared to their male counterparts. These discrepancies are partly explained by the lack
of literature available pertaining to female team sport athletes; and in particular, netball.
2. Measurement of Aerobic Fitness
The ‘gold standard’ measure of aerobic fitness is maximal oxygen uptake ( VO2 max ),
which is “the maximum rate that oxygen can be taken up from the ambient air and
transported to and used by cells for cellular respiration during physical activity”
(Midgley, McNaughton & Wilkinson, 2006, p. 118). It can be obtained from gas
analyses, which is generally laboratory based, or, more commonly, using predictive
performance based field testing.
As previously mentioned, there is a lack of published data pertaining to VO2 max values
for female team sport athletes, especially when compared to their male counterparts. One
of the first studies to investigate the maximal oxygen uptake for female team sport
athletes was by Clark, Reed, Crouse and Armstrong (2003) with a squad of female
NCAA division 1 soccer players. This group of soccer players recorded a mean VO2 max
of 42.2 ± 4.9 ml.kg-1.min-1. Surprisingly, a latter study by Sporis, Jovanovic, Krakan and
Fiorentini (2011) which examined a squad of under 20 female soccer players recorded a
higher mean VO2 max of 47.2 ± 4.3 ml.kg-1.min-1. Similarly, Enemark-Miller, Seegmiller
6
and Rana (2009) investigated the maximal oxygen uptake of female NCAA Division 1
lacrosse players whom recorded a mean VO2 max of 45.7 ± 4.9 ml.kg-1.min-1.
Administering VO2 max tests is not always feasible or practical, especially when trying to
assess the aerobic capabilities of an entire squad of athletes. Therefore, indirect measures
of VO2 max were created to allow for testing large numbers of athletes simultaneously. The
Universite’ de Montreal Track Test (UM-TT), which was created in 1980 by Leger and
Boucher was one of the first field tests used to provide an indirect measure of VO2 max .
Previous research has shown that the UM-TT is both reliable and valid, as evidenced by

its strong correlation with VO2 max (Leger & Boucher, 1980). Additionally, the UM-TT
has been utilised to aid training prescription through the determination of a peak velocity
associated with the last completed stage of the test (Berthoin, Pelayo, Lensel-Corbei,
Robin & Gerbeaux, 1996; Berthoin, Baquet, Rabita, Lensell-Corbeil & Gerbeaux, 1999).
This method of establishing a peak velocity to facilitate training prescription has been

adapted from the velocity at VO2 max ( vVO2 max ) model which has been researched
extensively (Billat, Hill, Pinoteau, Petit & Koralsztein, 1996; Billat & Koralsztein, 1996;
Billat, Blondel & Berthoin, 1999; Billat et al, 2000; Billat et al, 2000; Billat, 2001;
Renoux, Petit, Billat & Koralsztein, 2000; Duffield & Bishop, 2008; Dupont, Blondel &
Berthoin, 2002; Dupont, Blondel, Lensel & Berthoin, 2002; Midgley & McNaughton,
2006; Midgley, McNaughton & Wilkinson, 2006; Midgley, McNaughton & Jones, 2007)

and has been used effectively to bring about improvements in VO2 max (Billat, 2001; Billat
et al, 2000; Denadi, Oritz, Greco & de Mello, 2006; Dupont, Akakpo & Berthoin, 2004;
7
Esfarjani & Laursen, 2007; Enoksen, Shalfawi & Tonnessen, 2001; Helgerud et al, 2006;
Midgley, McNaughton & Wilkinson, 2006; Midgley, McNaughton & Jones, 2007)
Similarly, time trials of varying distances have been used as an indirect measure of
aerobic fitness and training speeds (i.e. maximal aerobic speed [MAS]). However, unlike
the UM-TT, which is incrementally progressed, time trials require a self-selected pacing
strategy. This can be problematic if the participants completing the time trial are not
adept at using the correct pacing strategy, which is often the case when using time trials
with team sport athletes instead of experienced endurance runners (Gibson et al, 2006;
Gosztyla, Edwards, Quinn & Kenefick, 2006). This can potentially lead to erroneous
results which have obvious deleterious implications for both testing and training. More
specifically, it can result in an inaccurate assessment of aerobic fitness and determination
of MAS.
Conventional indirect maximal oxygen uptake protocols, such as the ones mentioned
above, involve continuous incremental exercise. However, a criticism of this type of
testing protocol is that it does not replicate the demands and movement patterns of team
sports. Team sports are typically intermittent in nature and the ability to repeatedly
perform high intensity intermittent exercise is arguably more important than maximal
oxygen uptake (Bangsbo, Iaia & Krustrup, 2008). Additionally, it is widely accepted that
for well conditioned individuals, transfer of training requires greater specificity than
required for novices (Siff & Verkhohansky, 1999). Thus, testing well trained team sport
athletes should involve intermittent activities similar to those they are exposed to in
8
competition. This should be expected to provide more accurate and sensitive measures of
aerobic fitness for team sport athletes.
The first test devised in an attempt to achieve this was the 20 m shuttle run (20 m SR) test
which was first published by Leger and Boucher (1980). The 20 m SR test was designed
to assess the aerobic fitness capabilities of school children, healthy adults and athletes
partaking in intermittent activities (Leger, Mercier, Gadoury & Lambert, 1988). Since its
inception, the 20 m SR test has been used extensively with a variety of populations,
ranging from school children to elite athletes, thus highlighting its versatility as an
assessment tool for determining aerobic fitness. Importantly, the 20 m SR test has been
validated as a reliable assessment of aerobic fitness as it has a strong association with
VO2 max (Ramsbottom, Brewer & Williams, 1988; Paliczka, Nichols & Boreham, 1987).
However, recent research has shown that, whilst aerobic fitness is important for team
sport performance, the ability to repeatedly perform high intensity efforts is equally as
important (Krustrup, Mohr & Amstrup, 2003; Dawson, Hopkinson, Appleby, Stewart &
Roberts, 2004). Thus, in team sport athletes it is imperative to measure both aerobic
fitness as well as the ability to repeatedly perform intermittent high intensity exercise.
2.1 YOYO Intermittent Recovery Tests
The YOYO Intermittent Recovery (YOYO IR) tests were specifically designed and
validated to evaluate team sport athletes aerobic fitness and ability to repeatedly perform
and recover from high intensity intermittent exercise (Bangsbo, Iaia & Krustrup, 2008;
9
Thomas, Dawson & Goodman, 2006). Used extensively in soccer (Bangsbo, Iaia &
Krustrup, 2008; Bangsbo, Mohr, & Krustrup, 2006; Krustrup, Mohr, Ellingsgaard &
Bangsbo, 2005) the YOYO IR test consists of repeated 2x20 m shuttle runs at increasing
speeds, with a 10 s active recovery period between every 2x20 m (Thomas, Dawson &
Goodman, 2006). The speeds, changes in direction and active recovery periods more
closely replicate the movement patterns of team sports than other continuous tests. The
YOYO IR test has two levels; the YOYO IR – Level 1 (IR1) and the YOYO IR – Level 2
(IR2). The YOYO IR1 is designed for use with low-level or developmental athletes,
whilst the YOYO IR2 is best utilised with well-conditioned or elite athletes (Thomas,
Dawson & Goodman, 2006). The YOYO IR1 commences at a slower speed and
predominantly measures an individual’s aerobic fitness capabilities (Bangsbo, Iaia &
Krustrup, 2008). Conversely, the YOYO IR2 commences at a faster speed and
predominantly evaluates a trained individual’s ability to repeatedly perform high intensity
efforts with a large contribution from the anaerobic energy systems (Bangsbo, Iaia &
Krustrup, 2008).
Recently, aerobic fitness data from the field and specifically the YOYO Intermittent
Recovery test – Level 1 (YOYO IR1), have been reported. In a group of under 21 female
state level hockey players, Thomas, Dawson & Goodman (2006) reported a YOYO IR1
mean total distance of 840 ± 280 m. Surprisingly, Sirotic & Coutts (2007) reported a
higher mean YOYO IR1 total distance (958 ± 368 m) in a group of moderately trained
female team sport athletes. The findings of Sirotic & Coutts (2007) are of particular
interest as their group, described as moderately trained female team sport athletes
10
consisting of regional level touch football, netball, soccer and hockey players, recorded a
higher mean YOYO IR1 total distance than state level hockey players (Thomas, Dawson
& Goodman, 2006). Additionally, a study by Krustrup, Mohr, Ellingsgaard & Bangsbo
(2005) with 14 elite female soccer players from the best Danish competition reported a
mean YOYO IR1 total distance of 1379 m (600 to 1960 m). The playing positions
included five defenders, five midfielders and four attackers. All of the players had at least
three years experience in this Danish league and were all regular first team members.
Therefore, the disparity in these YOYO results in comparison to results of the
aforementioned studies is no surprise due to the training status of the female soccer
players.
Data which have particular relevance to the present study is a squad of female state
institute level netball players, whom recorded a mean YOYO IR1 total distance of 1432 ±
431 m (Personal Communication). However, all of the abovementioned results seem
inferior when compared to the results recorded by a state level women’s hockey team,
which recorded a mean YOYO IR1 total distance of 1650 ± 441 m (Personal
Communication). It is apparent that these personally communicated YOYO IR1 results
would be regarded as elite when benchmarked against other previously reported YOYO
IR1 data for female team sport athletes.
11
3. Physiological Adaptations to Aerobic Energy System Conditioning
Numerous studies have shown that aerobic energy system conditioning or, more
specifically, interval training can induce metabolic (Holloszy & Coyle, 1984; Lucia,
Hoyos, Pardo & Chicharro, 2000), cardiovascular (Andrew, Guzman & Becklake, 1966;
Coyle, Hemmert & Coggan, 1986), neuromuscular (Lucia, Hoyos, Pardo & Chicharro,
2000) and pulmonary adaptations (Acevedo & Goldfarb, 1989; Casaburi, Storer, BenDov & Wasserman, 1987; Hill, Jacoby & Farber, 1991), although the specific
physiological adaptations that occur with training are dependant upon several factors,
some of which include; training intensity, frequency of exercise, exercise duration and
the initial training status of the individual. Of all the factors that impact on the
physiological adaptations to training, training intensity has been regarded as the most
important for inducing physiological adaptations that lead to VO2 max enhancement
(Midgley, McNaughton & Wilkinson, 2006; Midgley, McNaughton & Jones, 2007). It is
apparent that VO2 max is a product of maximal cardiac output and the maximal arterialmixed venous oxygen difference and, therefore, any improvement in either of these
adaptations should result in VO2 max enhancement (Midgley, McNaughton & Wilkinson,
2006).
Physiological adaptations may occur either centrally or peripherally, depending on the
intensity of the aerobic energy system conditioning (Saltin, Nazar & Costill, 1976).
Central adaptations primarily occur at an exercise intensity of 70-80% VO2 max , which
equates to ~80-90% maximum heart rate (Swain et al, 1994). Central adaptations include
12
an improvement in the heart’s capacity to pump blood primarily through an increase in
stroke volume, which occurs as a result of an increase in end-diastolic volume and an
increase in left ventricular mass (Astrand, & Rodahl, Dahl & StrØmme, 2003). Both of
these adaptations cause an increase in cardiac output when exposed to an effective
training stimulus. Whilst it is a contentious topic, it has been suggested that VO2 max is
primarily limited by cardiac output (Midgley, McNaughton & Wilkinson, 2006).
Improvements in cardiac output as a result of endurance training have been attributed to
increased stroke volume, as maximal heart rate either remains the same or decreases
(Saltin, Blomqvist & Mitchell et al, 1968 as cited in Midgley, McNaughton & Wilkinson,
2006). Moreover, it is thought that increased heart volume and contractility result in
improvements in stroke volume which reduce heart rate and as a result in the heart having
more time to fill between contractions. It has also been stated that there is also a strong
link between stroke volume and heart size (Brooks, Fahey & Baldwin, 2005). Most of the
published literature investigating the optimal training intensity to induce stroke volume
increases has suggested 75% VO2 max as being optimal. This is due to a stroke volume
plateau occurring at 40-50% VO2 max and mean arterial pressure at 70-80% VO2 max
(MacDougall & Sale, 1981). An initial study by Astrand, Cuddy, Saltin & Stenberg
(1964) suggested that stroke volume plateaus at around 40-75% VO2 max , and as exercise
intensity approaches VO2 max , stroke volume may even decrease. However, recent studies
using well trained individuals suggest the opposite actually occurs. As exercise intensity
approaches VO2 max , stroke volume and both systolic and mean arterial blood pressures
increase (Gledhill, Cox & Jamnick, 1994; Zhou et al, 2001).
13
Arterial-mixed venous oxygen difference increases slightly with endurance training
(Brooks, Fahey & Baldwin, 2005), and has been considered an integral physiological
adaptation in the quest to increase VO2 max (Saltin & Rowell, 1980). Hudlicka, Brown and
Eggington (1992) suggest that the primary stimulus for increasing cappillarisation is
increased capillary pressure and sheer stress stemming from an increase in blood flow
velocity. As a result of cardiac output and blood flow increasing linearly with exercise
intensity, there should be an intensity dependent increase in cappillarisation up to
VO2 max (Midgley, McNaughton & Wilkinson, 2006).
Conversely, peripheral adaptations occur as exercise intensity increases to greater than
80% VO2 max or 90% maximum heart rate (Swain et al, 1994) and, include increased
muscle cappillarisation, increased oxidative enzyme activity, increased mitochondrial
volume and density, and an increased ability to use fatty acids as an energy source. These
peripheral adaptations increase the ability of the working muscles to produce and use
adenosine triposhphate (ATP) (Brooks, Fahey & Baldwin, 2005) and, are most
commonly induced through the application of high intensity interval training (HIIT).
Moreover, the aforementioned central and peripheral adaptations which facilitate
improvements in aerobic fitness also induce physiological adaptations, such as: lower
blood lactate levels at given work loads; increased lactate tolerance and clearance;
increased rate of phosphocreatine resynthesis; improved buffering capacity; and
increased time to exhaustion at varied intensities (Tomlin & Wegner, 2001; Glaister,
14
2008). It is thought that an improvement in aerobic fitness enhances the ability of the
muscle to recover from anaerobic exercise by supplementing anaerobic energy during
exercise and by providing aerobically derived energy at a quicker rate during recovery
(Tomlin & Wegner, 2001). Thus, decreasing the reliance on the anaerobic glycolysis
energy system and resulting in lower blood and muscle lactate concentrations for the
same absolute submaximal workload (Karlson & Saltin, 1971). Additionally, it is thought
that muscle lactate removal is improved by increased buffering capacity and increased
blood flow; both of which are evident in endurance-trained individuals. As well as
improving the removal of lactate, enhanced oxygen delivery to muscles post-exercise can
accelerate the rate of phosphocreatine resynthesis, which has been shown to be an
oxygen-dependent process (Tomlin & Wegner, 2001).
In an applied context, enhancement of the aerobic energy system has been suggested to
transfer to the on-field physical activities of team sport athletes. It is evident from
performance analysis across various team sports that the majority of game time is spent
performing low to moderate intensity activities. However, whilst high intensity activities
are less frequent, they are often game-defining offensive or defensive activities and,
therefore, place large demands on the anaerobic energy system throughout a game (Stone
& Kilding, 2009). Despite this, the aerobic energy system is the predominant energy
system as it is active during both low and high intensity activity, whilst also aiding
recovery between bouts of high intensity activity (Tomlin & Wegner, 2001). More
specifically, it has been shown that a well developed aerobic energy system can have a
positive impact on team sport performance indicators, such as: increased ability to
15
perform high intensity efforts; increased total distance covered throughout a match;
increased level of work intensity during game play; increased ability to recover from high
intensity intermittent efforts; increased number of sprints performed during a match and
an improvement in the number of contests made or created (Bangsbo et al, 2008;
Helgerud et al, 2001; Krustrup et al, 2003). Despite the extensive research available
highlighting the importance of the aerobic energy system on team sport performance, the
vast majority of it has involved male team sport athletes. Thus, there is a definite gap in
the literature involving well trained and elite standard female team sport athletes and,
therefore, knowledge of female team sport athlete’s aerobic fitness is worthwhile and
useful for exercise prescription.
In a practical sense, once the aerobic assessment is complete, the results obtained can be
used for prescribing training; specifically, high intensity interval training. Measures
derived include velocity at VO2 max ( vVO2 max ) and maximal aerobic speed (MAS).
3.1 Velocity at VO2 max ( vVO2 max )
The term vVO2 max was introduced by Daniels & Scardina (1984) and can be defined as
the minimal velocity associated with VO2 max determined by an incremental treadmill test.
The parameter vVO2 max combines both VO2 max and running economy into a single factor,
which enables more specific identification of aerobic differences between various
catergories of runners. In fact, it has been shown that vVO2 max can explain differences in
16
performance that VO2 max or running economy used in isolation do not (Billat &
Koralsztein, 1996).
The vVO2 max concept was further investigated and validated in a latter paper by di
Prampero (1986), whilst Leger and Boucher (1980) introduced the term maximal aerobic
speed (MAS), which was obtained from a field test rather than a laboratory test.
3.2 Maximal Aerobic Speed (MAS)
MAS can also be defined as the minimal speed that elicits maximal oxygen consumption
(Lacour et al, 1991), but as opposed to utilising an incremental treadmill test,
performance based field measures such as the Univeriste’ de Montreal Track test (UMTT), 20 m SR, time trials of varying distances and, more recently, the YOYO Intermittent
Recovery tests (YOYO IR) and the 30-15 Intermittent fitness test (30-15) have been
utilised to determine MAS.
3.3 Determining MAS or vVO2 max to prescribe high intensity interval training
(HIIT)
Using MAS or vVO2 max to prescribe training has clear benefits; however, obtaining these
measures from the laboratory is not practical for most organisations and teams. Instead,
performance based field tests have been used as an indirect estimate of MAS and/or
17
vVO2 max (Lacour et al, 1991; Dupont et al, 2010; Dellal et al, 2008; Baquet et al, 2004);
the efficacy of such practices is, however, questionable.
Time trials (TT) of varying distances have been found to be reliable with a study by
Laursen et al (2007) investigating 1500 m (ICC = 0.95; CV = 2%) and 5000m time trials
(ICC = 0.88; CV = 3.3%). Similar distances have also been used to estimate vVO2 max ,
with a study by Lorenzen et al (2009) investigating the efficacy of an average velocity
for a 1500 m and 3000 m time trial to estimate vVO2 max . However, a limitation of
utilising time trials is pacing strategy (Gosztyla, Edwards, Quinn & Kenefick, 2006), as
there is often an element of learning that exists when running time trials as individuals
are often unsure as to how to pace themselves to obtain the fastest possible time. This is
particularly relevant when testing team sport athletes as opposed to highly skilled
distance runners. The issue with pacing strategies is eradicated when utilising other tests,
such as the 20 m SR, UM-TT, YOYO IR and 30-15, as the pacing in these tests is
dictated by audio signals.
Whilst accurate, the use of a graded treadmill test to determine the velocity at
VO2 max ( vVO2 max ) is expensive, time consuming and requires experienced personnel;
therefore, in some cases, it is not practical for use with a squad or in a group
environment. These concerns are removed when utilising either the 20 m SR, UM-TT,
YOYO IR1 or the 30-15, as they inexpensive, easy to administer, require very little
equipment and are practical for a team or group setting.
18
The 20 m SR test has been found to be reliable with an ICC of 0.98 (Leger & Lambert,
1982) and has also been utilised in the past to determine MAS. However, due to the slow
speeds at which the test is completed, it severely underestimates MAS (Gerbeaux et al,
1991). As such, it is apparent that the application of HIIT utilising MAS obtained from
the 20 m SR test as the intensity measure is ineffective and erroneous. Conversely, the
YOYO IR1, 30-15 and UM-TT are completed at much faster speeds which in turn, would
result in determined training speeds that more closely replicate vVO2 max values.
The UM-TT, originally developed by Leger and Boucher (1980), was found to be both a
valid (r = 0.97) and reliable (ICC = 0.94) estimate of VO2 max in both trained and untrained
males and females (Leger & Boucher, 1980). Additionally, the UM-TT has also been
utilised to establish training speeds (Dupont et al, 2010; Buchheit, 2008; Buchheit et al,
2009). However, the validity of the determined training speed for team sport athletes has
been questioned due to the protocol. More specifically, the UM-TT is completed on an
athletics track without any changes in direction and, thus, it would appear that the UMTT is more suited to establish training speeds for middle distance runners rather than
team sport athletes (Dupont et al, 2010).
Conversely, the 30-15 intermittent fitness test was developed by Buchheit (2008)
specifically for team sport athletes as the test protocol includes a change of direction. The
30-15 has been established as reliable test (ICC = 0.96) (Buchheit, 2005) which was
developed primarily to determine an individual’s maximal aerobic running speed (MRS)
for the purpose of HIIT prescription. However, it is apparent that the 30-15 overestimates
19
training speeds when compared to vVO2 max and the training speeds obtained from other
progressive field tests such as the UM-TT and the 20 m SR (Buchheit, 2008; Buchheit et
al, 2009).
Similarly, the YOYO IR tests have been developed to specifically evaluate a team sport
athlete’s ability to perform intense exercise (Bangsbo, Iaia, Krustrup, 2008). Unlike the
30-15 test, the YOYO IR tests were not devised with the purpose of establishing training
speeds, but rather to obtain pertinent information about an individual’s capacity to
perform repeated intense exercise (Bangsbo et al, 2008). Like the abovementioned
performance-based field tests, the YOYO IR tests have been found to be reliable;
Krustrup et al (2003) reported a CV of 4.9%, whilst Thomas, Dawson & Goodman
(2006) reported an ICC of 0.95 and CV of 8.7% for the YOYO IR1 and ICC of 0.86 and
CV of 12.7% for the YOYO IR2.
More recently a study by Dupont et al (2010) has compared the peak velocity achieved
during the YOYO IR1 (VYOYO) and the maximal aerobic velocity (MAV) determined
from the UM-TT. This is the first study published that investigated the efficacy of the
YOYO IR1 as a means of determining training speeds. The VYOYO obtained from the
YOYO IR1 significantly correlated to the MAV obtained from the UMTT. To date, this is
the only study that has looked at the efficacy of determining training speeds using the
YOYO IR1 test, highlighting the need to further validate the YOYO IR1 test as an
appropriate means of determining training speeds and, subsequently, direct training
prescription.
20
4. Using MAS or vVO2 max to prescribe high intensity interval training (HIIT)
Traditionally, coaches and athletes have used long slow distance (LSD) or continuous
training, which involves running at a moderate intensity for high volume, to bring about
improvements in aerobic fitness and, subsequently, improve athletic performance
(Föhrenbach, Mader & Hollman, 1987). However, simply increasing the volume of LSD
or continuous running to elicit further improvements in VO2 max has been proven to be
ineffective with well trained athletes (Laursen & Jenkins, 2002). Thus, training intensity
is regarded as the most important variable to manipulate when trying to induce further
improvements in VO2 max (Fox, Bartels & Billings, 1973).
It has been recommended that to improve an athlete’s VO2 max , exercise intensity should
be at, or near, VO2 max for as long as possible during bouts of activity (Dellal et al., 2008).
A study by Billat et al (2002) reported a 5.4% increase in VO2 max in well trained distance
runners despite a 10% reduction in running volume. This improvement was attributed to
the inclusion of training at 90-100% VO2 max . Numerous other studies involving well
trained distance runners and training intensities of 90-100% VO2 max have reported similar
positive findings (Smith, Coombes & Geraghty, 2003; Smith, McNaughton & Marshall,
1999; Billat & Koralsztein, 1996; Dupont et al, 2002). However, these results were not
found to be statistically significant, which is likely due to small sample sizes when using
well trained or elite athletes, rather than the larger cohorts when using recreationally
trained subjects.
21
In order to maximise the total amount of time and/or work performed at or near VO2 max ,
interval or intermittent training, comprising of active or passive periods of recovery
interspersed with periods of high intensity exercise, should be prescribed (Midgley &
McNaughton, 2006; Rozenek, Funato, Kubo, Hoshikawa & Matsuo, 2007). The concept
of interval training was first published in a scientific journal by Reindall and Roskmann
in 1959, but as with many training methods used with elite level performance, the science
lagged behind the practical application. In the 1950s, Emil Zatopek attributed his
Olympic success to the use of a novel training method; interval training. Stemming from
his success, middle and long-distance runners have adopted this training method to train
at velocities that replicate race pace or specific competition velocity (Billat, 2001).
In the 1960s, more thorough scientific research on interval training was conducted.
Pioneering Swedish physiologist Per OlØf Astrand investigated long interval training at a
velocity between critical velocity and vVO2 max , which equates to an intensity of 90-95%
vVO2 max . Astrand investigated the efficacy of 3 minute runs at 90-92% vVO2 max and
established that VO2 max was elicited in the final repetitions despite interspersing the 3
minute periods of work with passive recovery (Astrand, Astrand & Christensen, 1960).
Additionally, the efficacy of very short interval training was investigated by Christensen
et al (1960). The very short interval protocol consisted of 10 second runs at 100% of
vVO2 max interspersed with 10 seconds passive recovery and resulted in VO2 max being
obtained along with low blood lactate accumulation. These pioneering studies highlighted
the efficacy of using contrasting interval training protocols to elicit improvements in
VO2 max and, subsequently result in performance improvements. Undoubtedly, the
22
aforementioned research has had a profound positive impact on the current training
methods utilised by elite level middle and long-distance runners.
Evidently, the application of HIIT using MAS and/or vVO2 max as the intensity measure
for aerobic conditioning has been commonly utilised with middle and long-distance
runners with significant improvements in aerobic measures (Billat, 2001). However,
these methods have not received the same attention within a team sports context.
Traditionally, aerobic conditioning practices applied with team sports have been based on
anecdotal evidence and conditioning methods applied with steady state sports such as
rowing, swimming, cycling and running. As such, there is limited research available
focusing on aerobic conditioning methods and prescription of these methods for team
sports. Currently, however, there is an emerging trend within team sports to utilise
interval based conditioning methods over continuous or steady state type methods to
increase VO2 max by using MAS or vVO2 max as the intensity measure.
Numerous studies have been published which support the notion that HIIT is more
effective than more conventional training methods, such as continuous or steady state
training, when attempting to elicit exercise intensity at or near VO2 max for as long as
possible. One of the first studies published that looked at comparing continuous and
interval training was by Fox et al (1967). In this particular study, it was found that
interval training was effective in improving performance measures in highly trained
individuals. Similarly, a study by Billat et al (2000) compared a continuous run at a
supra-critical velocity (which was equivalent to 1.6 km·h-1 slower than vVO2 max ) to an
23
interval training protocol which consisted of 30 s work at 100% vVO2 max and 30 s active
recovery at 50% vVO2 max .The subjects used in this study were endurance trained males
and they were instructed to perform both protocols until volitional exhaustion. The
interval protocol with active recovery periods was more effective than the continuous run
when trying to maximise time spent at or near VO2 max (interval = 7 min 51 s at
VO2 max versus continuous = 2 min 42 s at VO2 max ).
Intensities above MAS and/or vVO2 max have also been shown to be effective when trying
to elicit improvements in VO2 max .A study by Dupont et al (2002) compared the time
spent at a high level of VO 2 in a continuous run at 100% vVO2 max and short intermittent
runs consisting of 15 s work at a range of supramaximal intensities (110%, 120%, 130%
and 140% vVO2 max ) and 15 s passive recovery. Like the Billat study above, the subjects
were instructed to run until volitional exhaustion. However, in contrast to the Billat study,
the subjects used in this study were male college students rather than endurance trained
runners. When looking at total time spent between 90% and 100% VO2 max , the
supramaximal runs at 110% (6 min 23 s) and 120% (5 min 23 s) were more effective than
both the continuous run (3 min 37 s) and the supramaximal runs at 130% (2 min 15 s) and
140% (1 min 17 s). It would appear from these results that supramaximal runs at 110%
would be most effective when trying to maximise the time spent above 90% VO2 max .
However, when you take into account time to exhaustion (tlim) at each intensity, and then
look at time spent at VO2 max as a percentage of tlim for each of the protocols, the results
change quite dramatically. Using this measure, the supramaximal runs at 120% are the
24
most the effective VO 2 stimulus with 58% of the 374 ± 234 s tlim spent at VO2 max . This
is significantly better when compared to the other supramaximal runs (110% - 17% tlim,
130% - 30% tlim, 140% - 48% tlim) and the continuous run (32% tlim).
Moreover, another study by Dupont, Akakpo & Berthoin (2004) looked at the effects of a
HIIT program with an elite soccer team. Stemming from the abovementioned Dupont et
al (2002) study, the HIIT sessions consisted of 12-15 efforts of 15 s at 120% MAS
interspersed with 15 sec passive recovery. Upon completion of the 10-week high
intensity interval program, the squad’s MAS significantly improved from 16.1 ± 0.8
km.h-1 to 17.3 ± 0.9 km.h-1. This improvement in MAS was significantly different from
the other periods of training. As such, it is apparent from the research available that the
application of HIIT is more effective as a means of sustaining VO2 max for as long as
possible and, subsequently, for improving VO2 max when compared to continuous type
training methods.
4.1 Benefits of MAS and vVO2 max to administer sessions
When devising and administering conditioning programs, utilising MAS or vVO2 max as
the measure of training intensity can be beneficial as it ensures that programs or sessions
are individualised. It also affords the conditioning coach more control in regard to
monitoring volume, intensity and workload, rather than utilising other conditioning
methods such as small sided games (Dellal et al, 2008) or relying on subjective measures
such as rating of perceived exertion to guide training intensity. And unlike other variables
25
considered when prescribing conditioning (e.g. percentage of maximal heart rate), both
MAS and vVO2 max are stable and less influenced by external factors such as heat,
humidity, dietary intake and hydration (Achten & Jeukendrup, 2003).
5 Aims of the Study
The primary aims of this study were to (1) compare the MAS obtained from the YOYO
IR1 with the vVO2 max obtained from a VO2 max (graded treadmill) test, and (2) assess the
strength of the relationship between these two aerobic measures (i.e. YOYO IR1 &
VO2 max ). A secondary aim was to examine the reliability of the YOYO IR1 test with
female netballers. Whilst the reliability of the YOYO IR1 test with female athletes has
been established previously, this is the first such study to investigate female netballers. It
is anticipated that this study will introduce a more accurate means of determining MAS
for the application of high intensity interval training with team sport athletes, specifically
female netballers, with relevance to other intermittent activities.
26
REFERENCES
Achten J and Jeukendrup A. Heart Rate Monitoring: Applications and Limitations. Sports
Medicine 33(7): 517-538, 2003.
Andrew, G. M., Guzman, C. A., & Becklake, M. R. (1966). Effect of athletic training on
exercise cardiac output Journal of Applied Physiology, 21(2), 603-608.
Astrand, I., Astrand, P. O., & Christensen, E. H. (1960). Intermittent muscular work. Acta
Physiology Scandinavia, 48, 448-453.
Astrand, I., Astrand, P. O., & Christensen, E. H. (1960). Circulatory and respiratory
adaptations to severe muscular work. Acta Physiology Scandinavia, 50, 254-258.
Astrand, I., Astrand, P. O., & Christensen, E. H. (1960). Myohemoglobin as an oxygenstore in man. Acta Physiology Scandinavia, 48, 454-460.
Astrand, P. O., Cuddy, T. E., Saltin, B., & Stenberg, J. (1964). Cardiac output during
submaximal and maximal work. Journal of Applied Physiology, 19, 268-274.
Astrand, P.O., Rodahl, K., Dahl, H.A., & StrØmme, S.B. (2003). Textbook of work
physiology. Physiological bases of exercise. (4th ed.). Human Kinetics.
Avevedo, E. O., & Goldfarb, A. H. (1989). Increased training intensity effects on plasma
lactate, ventilatory threshold, and endurance. Medicine & Science in sports &
Exercise 21(5), 563-568.
Baquet, G., Guinhouya, C., Dupont, G., Nourry, C., & Berthoin, S. (2004). Effects of a
short term interval training program on physical fitness in prepubertal children.
Journal of Strength and Conditioning Research, 18(4), 708-713.
Bangsbo, J., Iaia, M., & Krustrup, P. (2008). The Yo-Yo Intermittent Recovery Test: A
Useful Tool for Evaluation of Physical Performance in Intermittent Sports. [Review
Article]. Sports Medicine, 38(1), 37.51.
Bangsbo, J., Mohr, M., & Krustrup, P. (2006). Physical and metabolic demands of
training and match-play in the elite football player. Journal of Sport Sciences,
24(7), 665-674.
Berthoin, S., Pelayo, P., Lensel-Corbeil, G., Robin, H., & Gerbeaux, M. (1996).
Comparison of maximal aerobic speed as assessed with laboratory and field
measurements in moderately trained subjects. International Journal of Sports
Medicine, 17(7), 525-529.
27
Berthoin, S., Baquet, G., Rabita, J., Lensel-Corbeil, G., & Gerbeaux, M. (1999). Validity
of the Universite' de Montreal track test to assess the velocity associated with peak
oxygen uptake for adolscents. Journal of Sports Medicine and Physical Fitness,
39(2), 107-112.
Billat, V. L. (2001). Interval Training for Performance: Part 1 - Aerobic Interval Training
Sports Medicine, 31(1), 13-31.
Billat, V. L., Blondel, N., & Berthoin, S. (1999). Determination of the Velocity
Associated with the Longest Time to Exhaustion at Maximal Oxygen Uptake.
European Journal of Applied Physiology, 80, 159-161.
Billat, V. L., Demarle, A., & Paiva, M. (2002). Effect of training on the physiological
factors of performance in elite marathon runners (males and runners). International
Journal of Sports Medicine, 23, 336-341.
Billat, V. L., Hill, D. W., Pinoteau, J., Petit, B., & Koralsztein, J. P. (1996). Effect of
protocol on determination of velocity at VO2max and on its time to exhaustion.
Archives of Physiology and Biochemistry, 104(3), 313-321.
Billat, V. L., & Koralsztein, J. P. (1996). Significance of the velocity at VO2max and time
to exhaustion at this velocity. [Review Article]. Sports Medicine, 22(2), 90-108.
Billat, V. L., Morton, R. H., Blondel, N., Berthoin, S., Bocquet, V., Koralsztein, J. P., et
al. (2000). Oxygen kinetics and modelling of time to exhaustion whilst running at
various velocities at maximal oxygen uptake. European Journal of Applied
Physiology, 82, 178-187.
Billat, V. L., Slawinski, J., Bocquet, V., Demarle, A., Lafitte, L., Chassaing, P., et al.
(2000). Intermittent Runs at the Velocity Associated with Maximal Oxygen Uptake
Enables Subjects to Remain at Maximal Oxygen Uptake for a Longer than Intense
but Submaximal Runs. European Journal of Applied Physiology, 81, 201-208.
Bishop, D., Edge, J., & Goodman, C. (2004). Muscle buffer capacity and aerobic fitness
are associated with repeated-sprint ability in women. European Journal of Applied
Physiology, 92, 540-547.
Bishop, D., Lawrence, S., & Spencer, M. (2003). Predictors of repeated-sprint ability in
elite female hockey players. Journal of Science and Medicine in Sport, 6(2), 199209.
Borotikar, B. S., Newcomer, R., Koppes, R., & McLean, S. G. (2008). Combined effects
of fatigue and decision making on female lower limb landing postures: central and
peripheral contributions to ACL injury risk. Clinical Biomechanics, 23(1), 81-92.
28
Brooks, G.A., Fahey, T.D., & Baldwin, K.M. (2005). Exercise physiology. Human
bioenergetics and its application (4th ed.). McGraw-Hill, NY.
Buchheit, M. (2005). The 30-15 intermittent fitness test: reliability and implication for
interval training of intermittent sport players. ECSS Proceedings. Belgrade.
Buchheit, M. (2008). The 30-15 intermittent fitness test: Accuracy for individualizing
interval training of young intermittent sport players. Journal of Strength and
Conditioning Research, 22(2), 365-374.
Buchheit, M., Haddad, H. A., Millet, G. P., Lepretre, P. M., Newton, M., & Ahmaidi, S.
(2009). Cardirespiratory and cardiac autonomic responses to 30-15 intermittent
fitness test in team sport players. Journal of Strength and Conditioning Research,
23(1), 93-100.
Casaburi, R., Storer, T. W., Ben-Dov, I., & Wasserman, K. (1987). Effect of endurance
training on possible determinants of VO2 during heavy exercise. Journal of Applied
Physiology, 62(1), 199-207.
Christensen, E. H., Hedman, R., & Saltin, B. (1960). Intermittent and continuous running.
(A further contribution to the physiology of intermittent work.). Acta Physiology
Scandinavia, 50, 269-286.
Clark, M., Reed, D. B., Crouse, S. F., & Armstrong, R. B. (2003). Pre- and post-season
dietary intake, body composition, and performance indices of NCAA division I
female soccer players. International Journal of Sports Nutrition and Exercise
Metabolism, 13, 303-319.
Coyle, E. F., Hemmert, M. K., & Coggan, A. R. (1986). Effect of detraining on on
cardiovascular responses to exercise: role of blood volume. Journal of Applied
Physiology, 60(1), 95-99.
Daniels, J., & Scardina, N. (1984). Interval training and performance. Sports Medicine, 1,
327-334.
Dawson, B., Hopkinson, R., Appleby, B., Stewart, G., & Roberts, C. (2004). Comparison
of training activities and game demands in the Australian football league. Journal of
Science and Medicine in Sport, 7(3), 292-301.
Davidson, A., & Trewartha, G. (2008). Understanding the physiological demands of
netball: a time-motion investigation. International Journal of Performance Analysis
in Sport, 8(3), 1-17.
Dellal, A., Chamari, K., Pintus, A., Girard, O., Cotte, T., & Keller, D. (2008). Heart rate
responses during small sided games and short intermittent running training in elite
29
soccer players: a comparative study. Journal of Strength and Conditioning
Research, 22(5), 1449-1457.
Denadai, B. S., Oritz, M. J., Greco, C. C., & de Mello, M. T. (2006). Interval training at
95% and 100% of the velocity at VO2max: effects on aerobic physioligcal indexes
and running performance. Applied Physiology, Nutrition & Metabolism, 31(6), 737743.
di Prampero, P. E. (1986). The energy cost of human locomotion on land and in water.
International Journal of Sports Medicine, 7, 55-72.
Duffied, R., & Bishop, D. (2008). VO2 responses to running speeds above VO2max.
International Journal of Sports Medicine, 29, 494-499.
Dupont, G., Akakpo, K., & Berthoin, S. (2004). The Effect of In-Season, High Intensity
Interval Training in Soccer Players. Jounal of Strength and Conditioning Research,
18(3), 584-589.
Dupont, G., Blondel, N., & Berthoin, S. (2002). Time spent at VO2max: a methodological
issue. International Journal of Sports Medicine, 24, 291-297.
Dupont, G., Blondel, N., Lensel, G., & Berthoin, S. (2002). Critical Velocity and Time
Spent at a High Level of VO2 for Short Intermittent Runs ar Supramaximal
Velocities. Canadian Journal of Applied Physiology, 27(2), 103-115.
Dupont, G., Defontaine, M., Bosquet, L., Blondel, N., Moalla, W., & Berthoin, S. (2010).
Yo-Yo intermittent recovery test versus the Universite' de Montreal Track Test:
Relation with a high-intensity intermittent exercise. Journal of Science and
Medicine in Sport, 13(1), 146-150.
Enemark-Miller, E. A., Seegmiller, J. G., & Rana, S. R. (2009). Physiological profile of
women's lacrosse players. Journal of Strength and Conditioning
Research, 23(1), 39-43.
Enoksen, E., Shalfawi, S. A., & Tonnessen, E. (2011). The effect of high- vs. lowintensity training on aerobic capacity in well-trained male middle-distance runners.
Journal of Strength and Conditioning Research, 25(3), 812-818.
Esfarjani, F., & Laursen, P. B. (2007). Manipulating high-intensity interval training:
effects on VO2max, the lactate threshold and 3000m running performance in
moderately trained males. Journal of Science and Medicine in Sport, 10, 27-35.
Föhrenbach, R., Mader, A., & Hollman, W. (1987). Training intensity of elite male
distance runners. International Journal of Sports Medicine, 8, 8-11.
30
Fox, E. L., Billings, C. E., Bason, R., & Matthews, D. K. (1967). Improvement of
physical fitness by interval training, II: required training frequency. USA: Medical
Research and Development Command, Office of the Surgeon General, US Army,
Nov, 11.
Fox, E. L., Bartels, R. L., & Billings, C. E. (1973). Intensity and distance of interval
training and chanes in aerobic power. Medicine and Science in Sports and Exercise,
5, 18-22.
Gerbeaux, M., Lensil-Corbeil, G., Branly, G., Jacquet, A., Lefranc, J. F., Dierkins, J. M.,
et al. (1991). Estimation de la vitesse maximale ae´robie chez les e´le`ves des colle'
ges et lyce´es. Science, 13, 19-26.
Gibson, A. C., Lambert, E. V., Rauch, L. H. G., Tucker, R., Baden, D. A., Foster, C., et
al. (2006). The role of information processing between the brain and peripheral
physiological systems in pacing and perception of effort Sports Medicine, 36(8),
705-722.
Glaister, M. (2008). Multiple Sprint Work: Methodological, Physiological, and
Experimental Issues. International Journal of Sports Physiology and Performance,
3, 107-112.
Gosztyla, A. E., Edwards, D. G., Quinn, T. J., & Kenefick, R. W. (2006). The Impact of
Different Pacing Strategies on Five-Kilometre Running Time Trial Performance.
Journal of Strength and Conditioning Research, 20(4), 882-886.
Helgerud, J., Engen, L. C., Wisloff, U., & Hoff, J. (2001). Aerobic Endurance Training
Improves Soccer Performance. Medicine & Science in Sports & Exercise 33(11),
1925-1931.
Helgerud, J., Hoydal, K., Wang, E., Karlsen, T., Berg, P., Bjerkaas, M., et al. (2006).
Aerobic high-intensity intervals improve VO2max more than moderate training.
Medicine & Science in Sports & Exercise, 39(4), 665-671.
Hill, N. S., Jacoby, C., & Farber, H. W. (1991). Effect of an endurance triathlon on
pulmanory function. Medicine & Science in Sports & Exercise, 23(11), 1260-1264.
Holloszy, J. O., & Coyle, E. F. (1984). Adaptations of skeletal muscle to endurance
exercise and their metabolic consequences. Journal of Applied Physiology, 56(4),
831-888.
Hudlicka, O., Brown, M., & Eggington, S. (1992). Angiogenisis in skeletal and cardiac
muscle. Physiological Reviews, 72(2), 369-417.
Karlsson, J., & Saltin, B. (1971). Oxygen deficit and muscle metabolites in intermittent
exercise. Acta Physiology Scandinavia, 82, 115-122.
31
Kennedy, B., Appleby, B., & Piggot, B. (2011). An Investigation of the heart-rate profile
of elite netball match play. Proceedings of the Australian Conference of Science
and Medicine in Sport, Perth, 19-22 October 2011 (Vol.1). Sports Medicine
Australia.
Krustrup, P., Mohr, M., & Amstrup, T. (2003). The Yo-Yo intermittent recovery test:
physiological response, reliability and validity. Medicine & Science in Sports &
Exercise, 35(4), 697-705.
Krustrup, P., Mohr, M., Amstrup, T., Rysgaard, T., Johansen, J., Steensberg, A., et al.
(2003). The Yo-Yo Intermittent Recovery Test: Physiological Response, Reliability
and Validity. Official Journal of the American College of Sports Medicine, 35(4),
697-705.
Lacour, J. R., Padilla-Magunacelaya, S., Chatard, J. C., Arsac, L., & Barthelemy, J. C.
(1991). Assessment of running velocity at maximal oxygen uptake. European
Journal of Applied Physiology, 62, 77-82.
Laursen, P. B., & Jenkins, D. G. (2002). The scientific basis for high-intensity interval
training. Sports Medicine, 32(1), 53-73.
Laursen, P. B., Francis, G. T., Abbiss, C. R., Newton, M. J., & Nosaka, K. (2007).
Reliability of time-to-exhaustion versus time-trial running tests in runners.
Medicine & Science in Sports & Exercise, 39(8), 1374-1379.
Leger, L., & Boucher, R. (1980). An indirect continuous running multistage field test: the
University de Montreal track test. Canadian Journal of Applied Physiology, 5(2),
77-84.
Leger, L. A., & Lambert, J. (1982). A multistage 20-m shuttle run test to predict VO2max
European Journal of Applied and Occupational Physiology, 49, 1-12.
Leger, L. A., Mercier, D., Gadoury, C., & Lambert, J. (1988). The multistage 20 metre
shuttle run test for aerobic fitness. Journal of Sport Sciences, 6(2), 93-101.
Lorenzen, H. D., Williams, M. D., Turk, P. S., Meehan, D. L., & Cicioni-Kolsky, D. J.
(2009). Relationship between velocity reached at VO2max and time-trial
performance in elite Australian rules footballers Journal of Sports Physiology and
Performance, 4, 408-411.
Loughran, B. J., & O'Donoghue, P. G. (1999). Time-motion analysis of work-rate in club
netball. Journal of Human Movement Studies, 36, 37-50.
32
Lucia, A., Hoyos, J., Pardo, J., & Chicharro, J. L. (2000). Metabolic and neuromuscular
adaptations to endurance training in professional cyclists: a longitudinal study. The
Japanese Journal of Physiology, 50(3), 381-388.
MacDougall, D., & Sale, D. (1981). Continuous vs interval training: a review for the
athlete and the coach. Canadian Journal of Applied Physiology, 6, 93-97.
Midgley, A. W., & McNaughton, L. R. (2006). Time at or near VO2max during
Continuous and Intermittent Running. Jounal of Sports Medicine and Physical
Fitness, 46(1), 1-14.
Midgley, A. W., McNaughton, L. R., & Jones, A. M. (2007). Training to enhance the
physiological determinants of long-distance running performance. Sports Medicine,
37(10), 857-880.
Midgley, A. W., McNaughton, L. R., & Wilkinson, M. (2006). Is there an optimal
training intensity for enhancing the maximal oxygen uptake of distance runners?
Sports Medicine, 36(2), 117-132.
Otago, L. (1983). A game analysis of the activity of netball players. Sports Coach, 7, 2428.
Paliczka, V. J., Nichols, A. K., & Boreham, C. A. (1987). A multi-stage shuttle run as a
predictor of running performance and maximal oxygen uptake. British Journal of
Sports Medicine, 21(4), 163-165.
Ramsbottom, R., Brewer, J., & Williams, C. (1988). A progressive shuttle run test to
estimate maximal oxygen uptake. British Journal of Sports Medicine, 22(4), 141144.
Renoux, J. C., Petit, B., Billat, V. L., & Koralsztein, J. P. (2000). Calculation of times to
exhaustion at 100 and 120% maximal aerobic speed. Ergonomics, 43(2), 160-166.
Royal, K. A., Farrow, D., Mujika, I., & Halson, S. L. (2006). The effects of fatigue on
decision making and shooting skill performance in water polo players. Journal of
Sport Sciences, 24(8), 807-815.
Rozenek, R., Funato, K., Kubo, J., Hoshikawa, M., & Matuso, A. (2007). Physiological
Resonses to Interval Training Sessions at Velocities Associated with VO2max.
Journal of Strength and Conditioning Research, 21(1), 188-192.
Saltin, B., Nazar, K., Costill, D. L., Stein, E., Jansson, E., Essen, B., et al. (1976). The
nature of the training response; peripheral and central adaptations to one-legged
exercise. Acta Physiology Scandinavia, 96(3), 289-305.
33
Saltin, B., & Rowell, L. B. (1980). Functional adaptations to physical activity and
inactivity. Federation Proceedings, 39(5), 1506-1513.
Sirotic, A. C., & Coutts, A. J. (2007). Physiological and performance test correlates of
prolonged, high-intensity, intermittent running performance in moderately trained
women team sport athletes. Journal of Strength and Conditioning Research, 21(1),
138-144.
SporiŠ, G., Jovanović, M., Krakan, I., & Fiorentini, F. (2011). Effects of strength training
on aerobic and anaerobic power in female soccer players. Sport Science, 4(2), 3237.
Smith, T. P., Coombes, J. S., & Geraghty, D. P. (2003). Optimising High Intensity
Treadmill training using the running speed at Maximal O2 uptake and time for
which this can be maintained. European Journal of Applied Physiology, 89, 337343.
Smith, T. P., McNaughton, L. R., & Marshall, M. T. (1999). Effect of 4-wk training using
Vmax/Tmax on VO2max and performance in athletes. Medicine and Science in
Sports and Exercise, 31, 892-896.
Steele, J., & Chad, K. (1992). An analysis of the movement patterns of netball players
during match play: implications for designing training programs. Sports Coach, 15,
21-28.
Stone, N. M., & Kilding, A. E. (2009). Aerobic conditioning for team sport athletes.
Sports Medicine, 39(8), 615-642.
Swain, D. P., Abernathy, K. S., Smith, C. S., Lee, S. J., & Bunn, S. A. (1994). Target
heart rates for the development of cardiorespiratory fitness. Medicine & Science in
Sports & Exercise, 26(1), 112-116.
Thomas, A., Dawson, B., & Goodman, C. (2006). The Yo-Yo Test: Reliability and
Association with a 20-m Shuttle Run and VO2max. International Journal of Sports
Physiology and Performance, 1, 137-149.
Tomlin, D., L & Wegner, H, A. (2001). The Relationship between Aerobic Fitness and
Recovery from High Intensity Intermittent Exercise. [Review ]. Sports Medicine,
31(1), 1-11.
Verkhoshansky, Y., & Siff, M. (2009). Supertraining. (6th ed.). Verkhoshanksy.
Zhou, B., Conlee, R. K., Jensen, R., Fellingham, G. W., George, J. D., & Fisher, A. G.
(2001). Stroke volume does not plateau during graded exercise in elite male
distance runners. Medicine & Science in Sports & Exercise, 33(11), 1849-1854.
34
JOURNAL SUBMISSION
As required for International Journal of Sports Physiology & Performance
http://journals.humankinetics.com/submission-guidelines-for-ijspp
For examiner, please note, with regards to IJSPP submission guidelines:
 As the article is an original investigation, there is a word limit of 3,500 words and the
number of references is limited to 30.

All manuscripts must be typed single spaced in Times New Roman size 12 font.

In text referencing is designated by a superscripted numeral. The reference list is to
be single spaced, arranged in the order the works are first cited, and numbered
serially, with only one reference per number. The reference list follows the AMA
Manual Style, 10th edition.

Please note in Chapter 1 and Chapter 3, APA referencing style was utilised as per the
Australian Catholic University guidelines.
35
VALIDITY OF AEROBIC FITNESS MEASURES IN
NETBALLERS AND DETERMINATION OF TRAINING
SPEEDS FOR TRAINING AND TESTING
Submission Type: Original Investigation
NATHAN E. HEANEY
36
ABSTRACT
Literature pertaining to netball and netballers aerobic fitness is sparse. The purpose of
this study was to report aerobic fitness measures and derived training speeds of high
caliber netballers obtained from the laboratory ( VO2 max ) and the YOYO Intermittent
Recovery Level 1 field test (YOYO-IR1). It was anticipated that the findings would
support the use of the YOYO-IR1 and subsequent training speed derivatives for the
purpose of athlete monitoring and training intensity prescription. A squad of female state
institute netballers (n = 10; age = 19.4 ± 2.5 y; mass = 80.2 ± 14.8 kg; stature = 182.4 ±
6.0 cm) performed the VO2 max and YOYO-IR1 tests on separate occasions. The derived
training speed variables used in this study included: velocity at VO2 max ( vVO2 max ),
obtained from the laboratory; and two measures obtained from the YOYO-IR1 (YOYO
Maximal Aerobic Speed (MAS) and YOYO-MAS Equation). Consistent with other team
sport populations, there was a strong correlation between YOYO-IR1 total distance (m)

and VO2 max ; as well as between derived training speeds. However, the YOYO IR1
derived training speeds were both significantly faster when compared to vVO2 max . This
study provides aerobic fitness data in netballers from both laboratory and field based tests
that are currently unavailable, with the YOYO-IR1 a validated aerobic fitness assessment
for this population. However, when using YOYO-MAS or YOYO-MAS Equation to
prescribe training intensity based on recommendations in the literature that have

utilised vVO2 max , it is recommended that practitioners be cautious.
37
KEY WORDS
YOYO Intermittent Recovery Test, Maximal Aerobic Speed, Velocity at VO2 max ,
High Intensity Interval Training, Aerobic Conditioning Prescription
38
INTRODUCTION
Physical fitness tests can be effectively employed to evaluate an athlete’s training status
and, from those measures, used to prescribe and quantify training intensity. One
component of physical fitness that underpins team sport activities is the aerobic energy
system
(1)
and, therefore, time dedicated to training with the aim to improve or maintain
this energy system is well justified. Aerobic fitness is accurately assessed using maximal
oxygen uptake ( VO2 max ) techniques. It can be measured indirectly from ventilatory data,
which is generally laboratory-based, or, more commonly, estimated using performancebased field testing. Once VO2 max has been obtained, parameters such as velocity at
VO2 max ( vVO2 max ) and maximal aerobic speed (MAS) can be derived and used to quantify
training intensities for interval-based aerobic energy system conditioning (2,3,4).
The vVO2 max concept was introduced by Daniels and Scardina
(5)
and can be defined as
the minimal velocity associated with VO2 max determined by an incremental treadmill test
(2,3,6)
. Alternatively, MAS can be defined as the minimal speed that elicits maximal
oxygen consumption
(4)
and can be obtained from field measures such as the Univeriste
de Montreal Track Test (UMTT), 20m shuttle run (20m SR) and time trials of varying
distances
. Both vVO2 max and MAS are utilised to quantify training intensity,
(7,8)
particularly in the prescription of high-intensity interval training (HIIT). The application
of HIIT using MAS and/or vVO2 max as the intensity measure for aerobic conditioning has
39
been commonly utilised with middle and long distance runners, with significant
improvements in aerobic measures
(2,3,6)
. However, these methods have not received the
same attention within a team sport context and, to date, no data for netball have been
reported.
When devising and administering conditioning programs, utilising MAS or vVO2 max as
the measure of training intensity can be beneficial as it ensures that programs or sessions
are individualised. It affords the conditioning coach more control in regard to monitoring
volume, intensity and workload, rather than utilising other conditioning methods such as
small sided games
(9)
or relying on subjective measures such as rating of perceived
exertion to guide training intensity. Additionally, unlike other variables considered when
prescribing conditioning (e.g. percentage of maximal heart rate), both MAS and vVO2 max
are stable and less influenced by external factors such as heat, humidity, dietary intake
and hydration (10).
Using MAS or vVO2 max to prescribe training has clear benefits, although obtaining
vVO2 max from laboratory testing is not practical for most sporting organisations.
Performance-based field tests such as the UMTT, 20m SR and time trials have been used
to estimate MAS and/or vVO2 max (4,7,8,11). However, the accuracy of MAS obtained when
using these field tests can be problematic. For example, MAS obtained from time trials
40
cannot be used interchangeably with vVO2 max (8). In one of the aforementioned studies
(8)
,
it was found that MAS obtained from the 1500 m time trial was overestimated, and MAS
obtained from a 3200 m time trial was underestimated, when compared to vVO2 max . A
limitation of using time trial data as a comparison is that they are often obtained outdoors
on a running track and, thus, subjects are exposed to variable environmental conditions
which can impact on time trial performance and, subsequently, accuracy of the estimated
MAS.
A more novel approach emerging for determining training intensity is based on the
YOYO Intermittent Recovery tests (YOYO-IR). There are two YOYO variations; the
YOYO Intermittent Recovery Level 1 test (YOYO-IR1) and the YOYO Intermittent
Recovery Level 2 test (YOYO-IR2). The YOYO-IR1 test consists of repeated 2 x 20 m
shuttle runs at increasing speeds, with a 10 s active recovery period between every 2 x 20
m
(12)
. The speeds, changes in direction, and active recovery periods more closely
replicate the movement patterns of team sports than continuous incremental tests. Like
the UMTT, 20 m SR and time trials, the YOYO-IR1 predominantly measures an
individual’s aerobic fitness capabilities
(7,8,13,14)
. The YOYO-IR1 test was specifically
designed and validated to evaluate team sport athletes’ aerobic fitness and ability to
repeatedly perform and recover from high intensity intermittent exercise
(13,14,15)
.
Furthermore, the YOYO-IR1 has a strong relationship to distance covered on the field
during a soccer match (13) and has been shown to be sufficiently sensitive to detect fitness
changes over the course of a season
(13)
. It has also been shown to discriminate between
playing positions and between different levels of competency in elite junior team sport
41
athletes
(13,16)
. Lastly, given the physiological and movement demands of netball
(17)
, the
repeated 180 degree changes in direction and the intermittent nature of the YOYO-IR1
test is more applicable to netballers than other traditional continuous shuttle or straight
running tests.
One potential limitation of utilising the YOYO-IR1 to establish training intensity is the
fact that it may lack sufficient sensitivity to establish individualised training speeds for
training prescription. This is due to the fact that the speed of each level remains constant
throughout all the shuttles. To address this lack of test sensitivity, an equation devised by
Kuipers et al (18) can be utilised (see Methods section).
Given that deriving training intensity from the YOYO-IR1 is currently not well
established, the aim of this study was to examine the relationship between the YOYOIR1 test and VO2 max in state-level netballers. By comparing the laboratory-based vVO2 max
to the field measure, it is anticipated that the efficacy of using final speed obtained from
the YOYO-IR1 test (YOYO-MAS) to prescribe high intensity interval training will be
shown. Therefore, we hypothesised that the maximal values and training speeds obtained
from the YOYO-IR1 test and VO2 max test would be strongly related.
42
METHODS
Subjects
The University’s Human Research Ethics Committee approved the study and all
participants provided written informed consent. Ten state institute female netballers (age
= 19.4 ± 2.5 y; mass = 80.2 ± 14.8 kg; stature = 182.4 ± 6.0cm) who were injury free
participated in this study. The netballers were familiar with the YOYO-IR1 test prior to
the study. All testing was performed during the pre-season training phase to avoid any
disruption to competitive matches. In preparation for the testing, twenty-four hours
before each session participants were instructed to continue normal nutrition practices
(i.e. high carbohydrate meals, hydrate and avoid caffeine). The participants could
withdraw from the study at any time.
Methodology
Two testing sessions were completed by each participant. In the first session, the YOYOIR1 test was completed on a sprung wooden floor and scheduled as part of the aerobic
conditioning program. The second session involved the VO2 max test and was completed
within a two-week period after the YOYO-IR1 test. Participants were instructed to either
completely rest or only perform low to moderate intensity exercise in the 24 h before
testing sessions.
43
YOYO-IR1 testing protocol
The YOYO-IR1 consists of repeated 20 m shuttle runs at increasing speeds, with a 10-s
active recovery period between every 2 x 20 m (13). The test commenced at level 5, which
equates to 10 km·h-1 (or 2.78 m·s-1). One shuttle run was added to each level until level
14 commences (14.5 km·h-1 or 4.03 m·s-1). Thereafter, 0.5 km·h-1 speed increments were
utilised after the completion of each level (8 shuttle runs) until exhaustion. The
participants were removed from the test when they failed to reach the 20 m line before
the audio pacing signal on two consecutive occasions. The YOYO-IR1 was recorded as
total distance covered (m) (13,14,15). The YOYO-IR1 can also be recorded as a level and
shuttle percentage (15), however, total distance is the most reported measure found in the
literature. Both measures – total distance and level and shuttle percentage – have been
found to be reliable, with an intra-class correlation coefficient (ICC) of 0.95 recorded for
both measures (15). In the same study, the typical error was reported as 107 m for total
distance and 0.26 for level and shuttle percentage, while the coefficient of variation (CV)
was 8.7% and 1.9% respectively. In another study looking at the reliability of the YOYOIR1 test, the ICC was reported as 0.93 and the CV was 8.7% for total distance (14).
Finally, since previous studies have not used female netballers, a test–retest was
performed as part of the pilot study to ascertain whether the YOYO-IR1 test was a
reliable measure of aerobic capacity. The test–retest was performed using the same ten
netballers, plus six other professional netballers. Only total distance was assessed for
reliability. An ICC of 0.99 was recorded and the typical error was reported as 54.7 m. As
evidenced by the aforementioned information, the YOYO-IR1 is a reliable measure of
aerobic capacity in female netballers.
44
The speed at the last completed shuttle was recorded as the maximal aerobic speed
(YOYO-MAS). Additionally, the YOYO-MAS Equation was used to increase test
sensitivity. YOYO-MAS Equation = V + 0.5 x (N/8), where V signifies the velocity
during the next to last stage, 0.5 signifies the increment in speed after each level is
completed, N signifies the number of shuttle runs completed in the last stage, and 8
signifies the number of shuttle runs in each level from level 14 (18).
VO2 max testing protocol
Subjects performed a brief warm-up by running at an initial speed 8 km·h-1 for 1 minute
and increasing the running speed by 1 km·h-1 every minute for another 2 minutes. This
was followed by 3 minutes of passive recovery where they were fitted with a Team Polar
heart rate monitor (Polar Electro, Oy) and performed their own stretching routine before
beginning the test.
Subjects ran on a motorised treadmill (HP Cosmos) commencing at a speed of 10 km·h-1
at 0% gradient, with 0.5 km·h-1 increase every minute, until two of the below mentioned
criteria were met. This protocol has been described previously by Lorenzen (8). A
MOXUS metabolic system with Applied Electrochemistry analysers was used for expired
gas analysis, with subjects breathing through a Hans Rudolph one-way valve.
VO2 max was considered to be achieved when two of the following criteria were met:
45
(1) volitional exhaustion, (2) plateau in VO2 despite increase in running speed, (3) RER
greater than 1.20, or (4) heart rate within 5 bpm of predicted maximal heart rate (220age) (12).
The vVO2 max was recorded as the lowest speed at which VO2 max was achieved (11) or the
greatest speed that the subject was able to run for at least 30 s (12). If both were achieved
in the one test, the greatest speed that the subject was able to run for 30 s or more was
used as vVO2 max .
Statistical Analysis
All data analyses were performed utilising SPSS version 15 for Windows (Chicago,
Illinios). The appropriate data sets were tested for normal distribution using the ShapiroWilks test and descriptive data reported. Pearson’s correlation coefficient was used to test
the relationship between variables. Curve estimates provided in the SPSS software (e.g.,
quadratic, power and exponential) were used to check that a linear relationship was most
suitable. When appropriate, linear regression models were applied and the standard error
of estimate reported (SEE). To test the differences between the outcome variables,
dependent t-tests were used; effect size (d) and 95% confidence intervals were also
reported to aid the interpretation of the findings.
46
RESULTS
In the laboratory, a mean VO2 max of 45.3. ± 5.6 ml.kg-1.min-1 (min VO2 max = 36.5 ml.kg1
.min-1, max VO2 max = 51.3 ml.kg-1.min-1) was obtained. In the field, mean YOYO-IR1
final distance was 1434 ± 416 m (min = 720 m, max = 1880 m) which, in level and
shuttle terms, equates to level 17.1 (min 14.7, max = 18.4).
There was a strong correlation between YOYO-IR1 total distance (m) and VO2 max
(ml.kg-1.min-1), with r2 = 0.953 (Figure 1). However, no agreement was found for both
MAS measures (YOYO-MAS & YOYO-MAS Equation) and vVO2 max (Table 1). The
YOYO-MAS overestimated training speed by 0.13 m·s-1 (95% CI = 0.03 to 0.22 m·s-1; p
< 0.005; d = 0.57) when compared to the vVO2 max . Similarly, MAS established from the
YOYO-MAS Equation overestimated training speed by 0.20 m·s-1 (95% CI = 0.09 to 0.90
m·s-1; p < 0.005; d = 0.92) when compared to vVO2 max . When comparing the two training
speeds obtained via the YOYO-IR1 test, the YOYO-MAS Equation estimated a
significantly faster training speed than the YOYO-MAS (p < 0.001, d = 0.38; 95% CI = 0.10 to -0.04 m·s-1).
47
POSITIONS
GK
GS
MID
Fit line for Total
VO2max (ml.kg.min)
50.00
45.00
40.00
R Sq Linear = 0.934
750
1000
1250
1500
1750
YOYOIR1 (m)
Figure 1: Linear regression of YOYO-IR1 total distance and VO2 max for the entire squad
of female Netballers
As expected, the midcourt players performed better than the goal keepers and goal
shooters in both the VO2 max and YOYO-IR1 test; and as such recorded faster estimated
training speeds.
48
Table 1: VO2 max , YOYO-IR1 distance and training speeds for the netball squad (and for
different positions) obtained from the YOYO-IR1 and the VO2 max test
vVO2 max
-
(ml.kg
YOYO-
vVO2 max
MAS
YOYO-
YOYO-MAS
MAS
Equation
(m·s-1)
(m·s-1)
(m·s-1)
.min-1)
(m)
44.9 ± 5.7
1432 ± 431
4.27 ± 0.26
4.35 ± 0.09
4.42 ± 0.11
44.06 ± 4.29
1313 ± 243
4.26 ± 0.20
4.35 ± 0.09
4.42 ± 0.11
49.45 ± 1.68
1784 ± 10
4.44 ± 0.22
4.58 ± 0.00
4.62 ± 0.02
36.9 ± 0.57
740 ± 0
3.96 ± 0.10
4.10 ± 0.10
4.17 ± 0.01
1
Squad
(n = 10)
Goal Keepers
(n = 3)
Mid Court
(n = 5)
Goal Shooters
(n = 2)
Despite the fact that both YOYO-IR1 derived training speed were significantly faster
than vVO2 max , there was still a moderately strong correlation between all the training
speed variables (Table 2).
49
Table 2: Pearson’s correlation coefficient for training speeds
vVO2 max
vVO2 max
YOYO-MAS
YOYO-MAS
(m·s-1)
(m·s-1)
Equation (m·s-1)
1
0.826
0.808
0.826
1
0.980
0.808
0.980
1
-1
(m·s )
YOYO-MAS
-1
(m·s )
YOYO-MAS
Equation (m·s-1)
From our regression model that included the YOYO-IR1 distance, vVO2 max was
adequately predicted (R2 = 0.665). The derived equation 1 was a good fit and as follows:
vVO2 max (m·s-1) = 0.456250 (distance [km]) + 3.617444 ± 0.16
(1)
DISCUSSION
The aim of this study was to report and compare the training speeds and estimated
aerobic capacity obtained from a laboratory-based test and a field-based test. This is the
first study to report both VO2 max and YOYO-IR1 data for an entire squad of netballers.
The mean YOYO-IR1 total distance of 1432 ± 431 m (720 to 1880 m) for this group of
50
female netballers compares well with other female team sport athletes. In a group of elite
female soccer players, 1379 m (600 to 1960 m) was reported
(14)
; 958 ± 368 m (480 to
1840 m) for moderately trained female team sport athletes (19) and lastly, 840 ± 280 m for
-1
-1

state level hockey players (18). Similarly, the mean VO2 max of 44.9 ± 5.7 ml.kg .min (min
= 36.5 ml.kg-1.min-1, max VO2 max = 51.3 ml.kg-1.min-1) also compares well with other
female team sport athletes. A mean VO2 max of 47.2 ± 4.3 ml.kg-1.min-1 was recorded for
under 20 female soccer players (20); whilst a mean VO2 max of 42.2 ± 4.9 ml.kg-1.min-1 was
reported for NCAA Division 1 female soccer players during pre-season testing
(21)
.
Similarly, a mean VO2 max of 45.7 ± 4.9 ml.kg-1.min-1 was reported for a NCAA Division 1
women’s lacrosse team
. These YOYO-IR1 and VO2 max results add credence to the
(22)
training status of the netballers used in this study.
Furthermore, as found in other populations, differences between playing positions were
observed (13,14). As expected, mid-court players registered the highest VO2 max and YOYO
IR1 values. This could potentially be attributed to the fact that the mid-court players are
required to run greater distances during competitive play. The ‘mid-court’ includes
players from the following positions; goal attack (GA), goal defence (GD), wing attack
(WA), wing defence (WD) and/or centre (C). Conversely, goal shooters and goal keepers
are required to run the least during competition as the rules confine them to only one third
of the court. Subsequently, most of the goal shooters (GS) and goal keepers (GK) in this
study registered VO2 max and YOYO IR1 scores reflective of this. More specifically, the
goal shooters recorded lesser VO2 max and YOYO IR1 values when compared to the goal
keepers. This disparity could potentially be attributed to the goal keepers in this study
51
being required to play multiple positions, such as GD or WD, whereas goal shooters
typically only play in their preferred position. Lastly, this expectation for defenders to
play multiple positions could potentially explain the large variation in the results obtained
from the goal keepers. Currently there is no literature available which states this
preference for multiple positions, rather, this preference stems from the coaching
philosophies of netball coaches.
Based on the relationships found between the laboratory and field based test scores, this
is the first study to suggest that the YOYO-IR1 is a valid measure of aerobic capacity for
female netballers. Similar to previous studies involving males
(7,13,14,15)
; a strong
correlation between the YOYO-IR1 total distance (m) and VO2 max (ml.kg-1.min-1) was
found. Therefore, the YOYO-IR1 is a practical and cost effective method of measuring
aerobic fitness for netballers.
Yet, agreement between measures of MAS and
vVO2 max were deemed not acceptable. Both training speeds obtained from the YOYO-IR1
(i.e. YOYO-MAS and YOYO-MAS Equation) significantly overestimated training
speeds when compared to vVO2 max obtained via the VO2 max test. Therefore, the direct
derivatives of MAS from the YOYO-IR1 should not be used interchangeably with
vVO2 max . This overestimation of training speeds from the YOYO-IR1 test could be due
the requirements of their sport; female netballers are very proficient at changing
direction, which is a skill that is integral to success during competition. This particular
skill is also extremely important during the YOYO-IR1 test, with a 180 degree change of
direction completed for each shuttle.
52
The sample was an entire squad of state institute netballers and increasing sample size
was not logistically possible. Therefore, future work should attempt to validate the
regression model presented using another sample of netballers from other states or
countries. Furthermore, the sensitivity of the YOYO-IR1 test to detect changes in aerobic
fitness for netballers is presently unknown and also requires further work. This can be
achieved by measuring the squad longitudinally across a competitive season and at the
end of specific training cycles.
PRACTICAL APPLICATIONS
This study adds to previous reports that the YOYO-IR1 test provides the conditioning
coach working with female athletes a practical, time efficient and cost effective method
of measuring the aerobic capabilities of these athletes. Caution is advised to those
conditioning coaches who wish to estimate training speeds derived from the YOYO-IR1
for the prescription of vVO2 max / MAS guided interval training. Findings from this
investigation suggest that for netballers, MAS derived from YOYO-IR1 and YOYOMAS equation is over estimated compared to vVO2 max , and therefore, this will result in
athletes working at an intensity that is significantly higher than anticipated. For example,
if a practitioner prescribes training based off the recommendations published in the
literature which has looked at vVO2 max ,but instead, utilises either YOYO MAS or YOYO
MAS Equation, the difference in prescribed running velocity could be an average of 0.13
m·s-1 (YOYO MAS) and 0.20 m·s-1(YOYO MAS Equation), which equates to 0.5 km·h−1
and 0.75 km·h−1 respectively. In practical terms, if an athlete records a vVO2 max of 4.58
53
m s-1 and is prescribed 30 sec intervals at vVO2 max , that equates to a distance of 151.1m.
•
However, if the same athlete is prescribed 30 sec intervals at the equivalent intensity but
determined via YOYO MAS Equation the athlete will have to run 157.7m. Evidently,
this significant discrepancy can have negative implications on the impact of the training
prescribed, and subsequent physiological adaptations if not accounted for via the use of
the regression model presented in this study. This regression model has been shown to
accurately predict vVO2 max by reducing the obtained training speed (YOYO MAS or
YOYO MAS Equation) when YOYO IR1 distance is included into the regression
equation. For example, if a netballer obtained a YOYO IR1 total distance of 1780m, as
was the case with most of the midcourt players in this study, this would result in an
overestimated YOYO MAS of 4.58 m·s-1. However, when this result is factored into the
regression equation presented above, a predicted vVO2 max of 4.43 m·s-1 is established,
which is within 0.01 m·s-1 of the laboratory measure for the midcourt players. Thus,
verifying that validity of the regression equation presented.
54
REFERENCES:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Tomlin D, L and Wegner, H, A. The Relationship between Aerobic Fitness and
Recovery from High Intensity Intermittent Exercise. Sports Medicine. 2001;31:111.
Billat VL, Blondel N, Berthoin S. Determination of the Velocity Associated with
the Longest Time to Exhaustion at Maximal Oxygen Uptake. European Journal of
Applied Physiology 1999;80:159-161.
Billat VL, Koralsztein JP. Significance of the velocity at VO2max and time to
exhaustion at this velocity. Sports Medicine 1996;22:90-108.
Lacour JR, Padilla-Magunacelaya S, Chatard JC, Arsac L, Barthelemy JC.
Assessment of running velocity at maximal oxygen uptake. European Journal of
Applied Physiology 1991;62:77-82.
Daniels J, Scardina N. Interval training and performance. Sports Medicine
1984;1:327-334.
Billat VL. Interval Training for Performance: Part 1 - Aerobic Interval Training
Sports Medicine 2001;31:13-31.
Dupont G, Defontaine M, Bosquet L, Blondel N, Moalla W, Berthoin S. Yo-Yo
Intermittent Recovery Test versus the Universite de Montreal Track Test: Relation
with High Intensity Intermittent Exercise. Journal of Science and Medicine in
Sport: 2010;13(1):146-150.
Lorenzen C, Williams M, Turk P, Meehan DL, Cicioni Kolsky DJ. Relationship
between velocity reached at and time trial performances in elite Australian rules
footballers. International journal of sports physiology and performance 2009;4:408411.
Dellal A, Chamari K, Pintus A, Girard O, Cotte T, Keller D. Heart rate responses
during small sided games and short intermittent running training in elite soccer
players: a comparative study. Journal of Strength and Conditioning Research
2008;22:1449-1457.
Achten J, Jeukendrup A. Heart Rate Monitoring: Applications and Limitations.
Sports Medicine. 2003;33:22.
Baquet G, Guinhouya C, Dupont G, Nourry C, Berthoin S. Effects of a short term
interval training program on physical fitness in prepubertal children. Journal of
Strength and Conditioning Research 2004;18:708-713.
Smith TP, Coombes JS, Geraghty DP. Optimising High Intensity Treadmill training
using the running speed at Maximal O2 uptake and time for which this can be
maintained. European Journal of Applied Physiology. 2003;89:337-343.
Bangsbo J, Iaia, M, Krustrup, P. The Yo-Yo Intermittent Recovery Test: A Useful
Tool for Evaluation of Physical Performance in Intermittent Sports. Sports
Medicine. 2008;38:37-51.
Krustrup P, Mohr T, Amstrup T, Rysgaard J, Johansen A, Pedersen PK, Bangsbo J.
The Yo-Yo Intermittent recovery test: Physiological response, reliability, and
validity. Medicine and Science in Sport and Exercise. 2003;35:697-705.
55
15. Thomas A, Dawson B, Goodman C. The Yo-Yo Test: Reliability and Association
with a 20-m Shuttle Run and VO2max. International Journal of Sports Physiology
and Performance. 2006;1:137-149.
16. Veale JP, Pearce AJ, and Carlson JS. The YOYO intermittent recovery test (level 1)
to discriminate elite junior Australian football players. Journal of Science and
Medicine in Sport. 2010;13:329-331.
17. Davidson A, Trewartha G. Understanding the physiological demands of netball: A
time motion investigation. International journal of performance analysis 2008;8:117.
18. Kuipers H, Verstappen FTJ, Keizer A, Geurten P, van Kranenburg G. Variability
of aerobic performance in the laboratory and its physiologic correlates. International
journal of sports medicine. 1985;4:197-201.
19. Sirotic AC, Coutts AJ. Physiological and performance test correlates of prolonged,
high intensity, intermittent running performance in moderately trained women team
sport athletes. Journal of strength and conditioning research. 2007;21:138-144.
20. Sporis G, Jovanovic M, Krakan I, Fiorentini F. Effects of strength training on
aerobic and anaerobic power in female soccer players. Sport Science. 2011;4(2):
32-37.
21. Clark M, Reed DB, Crouse SF, Armstrong RB. Pre- and post-season dietary intake,
body composition, and performance indices of NCAA division I female soccer
players. International Journal of Sport Nutrition and Exercise Metabolism
2003;13:303-319.
22. Enemark-Miller EA, Seegmiller JG, Rana SR. Physiological profile of women’s
lacrosse players. Journal of Strength and Conditioning Research 2009;23(1):39-43.
56
EXTENDED METHODOLOGY
57
Participants
The University’s Human Research Ethics Committee approved the study and all
participants provided written informed consent. Ten state institute female netballers (age
= 19.4 ± 2.5 y; mass = 80.2 ± 14.8 kg; stature = 182.4 ± 6.0 cm) and six professional
female netballers (age = 25.0 ± 2.3 y; mass = 72.2 ± 9.9 kg; stature = 179.0 ± 5.0 cm)
who were injury free participated in this study. The netballers were familiar with the
YOYO IR1 test prior to the study. All testing was performed during the pre-season
training phase to avoid any disruption to competitive matches. In preparation for the
testing, participants were instructed to continue normal nutrition practices in the 24 hours
prior (i.e. high carbohydrate meals, hydrate and avoid caffeine). The participants could
withdraw from the study at any time.
Procedure
All participants (n = 16) completed two YOYO IR1 tests, performed on a sprung floor
and scheduled as part of the aerobic conditioning program. The YOYO IR1 test-retest
was completed within 7 days. A third testing session was completed only by the state
institute netballers (n = 10) and involved the VO2 max test and was completed within a twoweek period after the initial YOYO IR1 test. Participants were instructed to either
completely rest or only perform low to moderate intensity exercise in the 24 h before
testing sessions.
58
YOYO IR1 testing protocol
The YOYO IR1 consists of repeated 20 m shuttle runs at increasing speeds, with a 10-s
active recovery period between every 2 x 20 m (Bangsbo, Iaia & Krustrup, 2008). The
test commenced at level 5, which equates to 10 km·h-1. One shuttle run was added to each
level until level 14 was commenced (14.5 km·h-1). Thereafter, 0.5 km·h-1 speed
increments were utilised after the completion of each level (8 shuttle runs) until
exhaustion.
59
Table 1: Number of shuttles, speed and distance completed for each YOYO IR1 level
Distance Completed
Number of Shuttles
Speed
Per Level
(km·h-1).
YOYO IR1 Level
Per Level
(m)
5
1
10
40
9
1
11
40
11
2
13
80
12
3
13.5
120
13
4
14
160
14
8
14.5
320
15
8
15
320
16
8
15.5
320
17
8
16
320
18
8
16.5
320
19
8
17
320
20
8
17.5
320
21
8
18
320
22
8
18.5
320
23
8
19
320
Participants were removed from the test when they failed to reach the 20 m line before
the audio pacing signal on two consecutive occasions. The YOYO IR1 was recorded as
total distance covered (m) (Bangsbo, Iaia & Krustrup, 2008; Krustrup et al, 2003;
60
Thomas, Dawson & Goodman, 2006). The YOYO IR1 can also be recorded as a level
and shuttle percentage (Thomas, Dawson & Goodman, 2006), however, total distance is
the most reported measure found in the literature. Both measures – total distance and
level and shuttle percentage – have been found to be reliable, with an intra-class
correlation coefficient (ICC) of 0.95 recorded for both measures (Thomas, Dawson &
Goodman, 2006). In the same study, the typical error was reported as 107 m for total
distance and 0.26 for level and shuttle percentage, while the coefficient of variation (CV)
was 8.7% and 1.9%, respectively. In another study looking at the reliability of the YOYO
IR1 test, the ICC was reported as 0.93 and the CV was 8.7% for total distance (Krustrup
et al, 2003).
The speed at the last completed shuttle was recorded as the maximal aerobic speed
(YOYO MAS). Additionally, the YOYO MAS Equation was used to increase test
sensitivity. YOYO MAS Equation = V + 0.5 x (N/8), where V signifies the velocity
during the next to last stage, 0.5 signifies the increment in speed after each level is
completed, N signifies the number of shuttle runs completed in the last stage, and 8
signifies the number of shuttle runs in each level from level 14 (Kuipers et al, 1985).
VO2 max testing protocol
Participants performed a brief warm-up by running at an initial speed of 8 km·h-1 for 1
minute and increasing the running speed by 1 km·h-1 every minute for another two
minutes. This was followed by 3 minutes of passive recovery where they were fitted with
61
a Team Polar heart rate monitor (Polar Electro, Oy) and performed their own stretching
routine before beginning the test.
Participants ran on a motorised treadmill (H/P/Cosmos Sports and Medical GmbH, Pulsar
3P 4.0, Amsporplatz, Nussdorf-Traunstein, Germany) commencing at a speed of 10
km·h-1 at 0% gradient, with 0.5 km·h-1 increases every minute, until two of the below
criteria were met. This protocol has been described previously by Lorenzen et al (2009).
A MOXUS metabolic system (AEI Technologies, Pittsburgh, PA) with Applied
Electrochemistry analysers was used for expired gas analysis, with subjects breathing
through a Hans Rudolph one-way valve.
VO2 max was considered to be achieved when two of the following criteria were met:
(1) volitional exhaustion, (2) plateau in VO 2 despite an increase in running speed
(Howley, Bassett & Welch, 1995), (3) RER greater than 1.20, or (4) heart rate within 5
bpm of predicted maximal heart rate (220-age) (Smith, Coombes & Geraghty, 2003).
The vVO2 max was recorded as the lowest speed at which VO2 max was achieved (Billat &
Koralsztein, 1996) or the greatest speed that the subject was able to run for at least 30 s
(Smith, Coombes & Geraghty, 2003). If both were achieved in the one test, the greatest
speed that the subject was able to run for 30 s was used as vVO2 max .
62
Statistical Analysis
All data analyses were performed utilising SPSS version 15 for Windows (Chicago,
Illinios). The appropriate data sets were tested for normal distribution using the ShapiroWilks test and descriptive data reported. Pearson’s correlation coefficient was used to test
the relationship between variables. Curve estimates provided in the SPSS software (e.g.,
quadratic, power and exponential) were used to check that a linear relationship was most
suitable. When appropriate, linear regression models were applied and the standard error
of estimate (SEE) reported. Multivariate approaches were also considered based on the
significance of the coefficients and changes in R2 and SEE following their application. To
test the differences between the outcome variables, dependent t-tests were used; effect
size (d) and 95% confidence intervals were also reported to aid the interpretation of the
findings.
63
REFERENCES
Achten J and Jeukendrup A. Heart Rate Monitoring: Applications and Limitations. Sports
Medicine 33(7): 517-538, 2003.
Bangsbo, J., Iaia, M., & Krustrup, P. (2008). The Yo-Yo Intermittent Recovery Test: A
Useful Tool for Evaluation of Physical Performance in Intermittent Sports. [Review
Article]. Sports Medicine, 38(1), 37-51.
Billat, V. L. (2001). Interval Training for Performance: Part 1 - Aerobic Interval Training
Sports Medicine, 31(1), 13-31.
Billat, V. L., Blondel, N., & Berthoin, S. (1999). Determination of the Velocity
Associated with the Longest Time to Exhaustion at Maximal Oxygen Uptake.
European Journal of Applied Physiology, 80, 159-161.
Billat, V. L., & Koralsztein, J. P. (1996). Significance of the velocity at VO2max and time
to exhaustion at this velocity. [Review Article]. Sports Medicine, 22(2), 90-108.
Davidson, A., & Trewartha, G. (2008). Understanding the physiological demands of
netball: a time-motion investigation. International Journal of Performance Analysis
in Sport, 8(3), 1-17.
Dellal A, Chamari K, Pintus A, Girard O, Cotte T, and Keller D. Heart rate responses
during small sided games and short intermittent running training in elite soccer
players: a comparative study. Journal of Strength and Conditioning Research 22:
1449-1457, 2008.
Dupont, G., Defontaine, M., Bosquet, L., Blondel, N., Moalla, W., & Berthoin, S. (2010).
Yo-Yo intermittent recovery test versus the Universite' de Montreal Track Test:
64
Relation with a high-intensity intermittent exercise. Journal of Science and
Medicine in Sport, 13(1), 146-150.
Daniels, J., & Scardina, N. (1984). Interval training and performance. Sports Medicine, 1,
327-334.
Gosztyla, A. E., Edwards, D. G., Quinn, T. J., & Kenefick, R. W. (2006). The Impact of
Different Pacing Strategies on Five-Kilometre Running Time Trial Performance.
Journal of Strength and Conditioning Research, 20(4), 882-886.
Howley, E. T., Bassett, D. R., & Welch, H. G. (1995). Criteria for maximal oxygen
uptake: review and commentary. Medicine & Science in Sports & Exercise, 27(9),
1292-1301.
Krustrup, P., Mohr, M., Amstrup, T., Rysgaard, T., Johansen, J., Steensberg, A., et al.
(2003). The Yo-Yo Intermittent Recovery Test: Physiological Response, Reliability
and Validity. Official Journal of the American College of Sports Medicine, 35(4),
697-705.
Kuipers, H., Verstappen, F. T. J., Keizer, A., Geurten, P., & van Kranenburg, G. (1985).
Variability of aerobic performance in the laboratory and its physiologic correlates.
International Journal of Sports Medicine, 4, 197-201.
Lacour, J. R., Padilla-Magunacelaya, S., Chatard, J. C., Arsac, L., & Barthelemy, J. C.
(1991). Assessment of running velocity at maximal oxygen uptake. European
Journal of Applied Physiology, 62, 77-82.
Lorenzen, H. D., Williams, M. D., Turk, P. S., Meehan, D. L., & Cicioni-Kolsky, D. J.
(2009). Relatinship between velocity reached at VO2max and time-trial
performance in elite Australian rules footballers Journal of Sports Physiology and
Performance, 4, 408-411.
65
Smith, T. P., Coombes, J. S., & Geraghty, D. P. (2003). Optimising High Intensity
Treadmill training using the running speed at Maximal O2 uptake and time for
which this can be maintained. European Journal of Applied Physiology, 89, 337343.
Thomas, A., Dawson, B., & Goodman, C. (2006). The Yo-Yo Test: Reliability and
Association with a 20-m Shuttle Run and VO2max. International Journal of Sports
Physiology and Performance, 1, 137-149.
Tomlin, D., L & Wegner, H, A. (2001). The Relationship between Aerobic Fitness and
Recovery from High Intensity Intermittent Exercise. [Review ]. Sports Medicine,
31(1), 1-11.
Veale J.P., Pearce A.J., & Carlson J.S. (2010). The YOYO intermittent recovery test
(level 1) to discriminate elite junior Australian football players. Journal of Science
and Medicine in Sport 13, 329-331.
66
APPENDIX 1: Letter of invitation to the participant
TITLE OF PROJECT: Comparison of the VO2 max test and YOYO Intermittent Recovery Test
as a determination of Maximal Aerobic Speed and evaluation of aerobic power
PRINCIPAL SUPERVISOR: Dr. Morgan Williams
STUDENT RESEARCHER: Nathan Heaney
PROGRAM IN WHICH ENROLLED: Exercise Science (Honours)
Dear Sir/Madam
You are invited to participate in a research study being conducted by the School of Exercise
Science, Australian Catholic University. The research study is looking at two different tests of
aerobic fitness – a laboratory based assessment (VO2 max) and a field based assessment (YOYO
IR1). The testing will commence from the 1st March 2009 and will be performed between the
hours of 05:00 and 21:00. The two aerobic measures will each require 30 minutes to complete
and the times of testing will be tailored to suit the schedule of the athletes. The aim of the study is
to validate the use of the YOYO IR1 as an accurate measure of aerobic fitness and to direct
aerobic conditioning through the determination of Maximal Aerobic Speed (MAS).
As part of the study, you will be asked to complete the laboratory assessment at ACU to establish
your VO2 max and velocity at VO2 max (vVO2 max). The protocol utilised for the VO2 max test
will be adapted to ensure accurate determination of both VO2 max and vVO2 max. It involves
running on a treadmill for approximately 15 minutes with gas analysis. In addition, you will be
asked to complete two trials of the field test within a 5-7 day period at the VIS. The importance of
the two trials is to establish reliability of the test. The field test consists of repeated 20m shuttle
runs at increasing speeds, with a 10-second active recovery period between every 2x20m.
The risk of injury to you is minimal and no more than a typical training session. Furthermore, this
study has undergone an important and vigorous process to ensure all risks to you have been
identified and minimised. Thus, the study is justified by the university’s ethics committee. This
study presents an opportunity for you to utilise testing methods (VO2 max) that are not readily
available at the VIS due to cost, whilst also developing a greater understanding of how your body
functions. Moreover, the additional knowledge will enable the coaches and physical preparation
staff to devise more specific conditioning programs.
The total time per session will be approximately 30 minutes, including warm-up. The study is
expected to last approximately 10 days, but the testing will be organised around your
commitments, therefore, minimising any inconvenience.
Before commencing the study we require that your contact information is provided. This
information is required for us to maintain contact during the study and to provide feedback at the
conclusion of the study. While all individual results will be confidential, the results from the
study will help with devising more specific, individualised and effective aerobic conditioning
programs for the netball squads at the VIS.
All personal information will be kept confidential and destroyed at the conclusion of the study.
You are free not to participate if you do not wish to do so, and are free to withdraw at any time.
Withdrawal from the study will not have any consequences regarding your VIS scholarship. In
67
addition, you are free to withdraw your consent at any time and withdraw any information
supplied. This will not impact on your team selection.
The data collected will be explained to you and your coach in detail post-analysis in an organised
interview by one of the researchers. More over, the data collection will not impede or interfere
with the your normal training regimes as it will be scheduled into the annual plan, but rather act
as a means for increasing your knowledge and gaining additional information, which can be
incorporated into future training programs.
If you would like to take part in this study, please fill in the attached consent form and return it to:
Dr. Morgan Williams
Australian Catholic University
School of Exercise Science
115 Victoria Parade
Fitzroy, Vic 3065
Should you have any queries please contact Dr. Morgan Williams on (03) 9953 3420
Please be advised that this study has been presented and approved by the Human
Research Ethics Committee at Australian Catholic University. In the event that you have a query
or complaint about the way that you or your child have been treated during the study, you may
write care of the nearest research branch of Office of Research
Chair, Human Research Ethics Committee
C/o Office of Research
Australian Catholic University
115 Victoria Parade
Fitzroy VIC 3065
Tel: 03 9953 3157
Fax: 03 9953 3305
Any complaint made will be treated in confidence, investigated fully and the participant informed
of the outcome. If you agree that your child may participate in this project, please complete the
details on both copies of the Informed Consent form and sign them, retain one copy for your
records and return the other copy to the supervisor at the Australian Catholic University. Thank
you for your co-operation with this important research.
Yours faithfully,
Dr. Morgan Williams, Principle Supervisor
The physical demands of this project remain below those imposed routinely during typical
training sessions due to the controlled environment. In the unlikely event of player injury, please
note that contact details for medical staff are provided below.
Team sports physician: Dr Susan White, Olympic Park Sports Medicine Clinic. Mobile: 0412 304
915 or Office: 9427 0366
68
Team physiotherapists: Steve Hawkins, Olympic Park Sports Medicine Clinic. Mobile: 0416 078
499 or Office 9427 0366 and Heidi Pollington, Prahran Lifecare Sports Medicine. Mobile: 0409
863 003 or Office: 9529 8899
Sport Psychologist: Steven Bannon, Victorian Institute of Sport. Mobile: 0417 562 221 or Office:
9425 0080
69
APPENDIX 2: Consent Form
Consent form: (Copy 1 – to be retained by Participant if over 18 years of age)
Name of participant
Date of birth
Gender
I, ______________________________________________________________ ______________of
____________________________________________________________________________________
Hereby consent to participating in the research study on the determination of training speeds for netball to
be taken by Dr. Morgan Williams, Dr. Justin Kemp, Dr. Christian Lorenzen and Nathan Heaney of the
Australian Catholic University. I am aware that as part of the study I may be asked to perform a VO 2 max
test and a test - retest of the YOYO IR1. The duration of the testing will be approximately 30 minutes per
bout, with a test on 3 separate occasions over a 10-14 day period. The testing is likely to commence on
March 1st 2009 and will be conducted between the hours of 07:00 and 20:00 at the Victorian Institute of
Sport and the Australian Catholic University, St Patrick’s campus.
I understand that
(a)
(b)
(c)
(d)
(e)
(f)
I am free not to participate if I do not wish to do so and that I am free to withdraw at any time;
I am free to withdraw my consent at any time and withdraw any information supplied by myself;
Withdrawal from this study will not impact on my VIS scholarship;
The project is for the purpose of research and is not for treatment;
The results from this study may be summarized and appear in publications or may be provided to
other researchers in a form that does not identify participants in anyway
Any information I supply will be confidential.
Signed ___________________________________ Date;
(Participant)
_____________________
SIGNATURE OF PRINCIPAL
SUPERVISOR:…………………………………………DATE:……/……/………
SIGNATURE OF STUDENT
RESEARCHER:…………………………………………DATE:…../……./……….
The physical demands of this project remain below those imposed routinely during typical training sessions due to the
controlled environment. In the unlikely event of player injury, please note that contact details for medical staff are
provided below.
Team sports physician: Dr Susan White, Olympic Park Sports Medicine Clinic. Mobile: 0412 304 915 or Office: 9427
0366
Team physiotherapists: Steve Hawkins, Olympic Park Sports Medicine Clinic. Mobile: 0416 078 499 or Office 9427
0366 and Heidi Pollington, Prahran Lifecare Sports Medicine. Mobile: 0409 863 003 or Office: 9529 8899
Sport Psychologist: Steven Bannon, Victorian Institute of Sport. Mobile: 0417 562 221 or Office: 9425 0080
Australian Catholic University Limited A.C.N. 050 192 660
St. Patrick’s Campus115 Victoria Parade, Fitzroy, Victoria 3045, Australia
Mail: Locked bag 4115 Fitzroy MDC 3065, Australia
Telephone 61 3 9953 3041 Facsimile 61 3 9953 3095
70
Consent form: (Copy 2 – to be retained by Principal Supervisor)
Name of participant
Date of birth
Gender
I, ______________________________________________________________ ______________of
____________________________________________________________________________________
Hereby consent to participating in the research study on the determination of training speeds for netball to
be taken by Dr. Morgan Williams, Dr. Justin Kemp, Dr. Christian Lorenzen and Nathan Heaney of the
Australian Catholic University. I am aware that as part of the study I may be asked to perform a VO 2 max
test and a test - retest of the YOYO IR1. The duration of the testing will be approximately 30 minutes per
bout, with a test on 3 separate occasions over a 10-14 day period. The testing is likely to commence on
March 1st 2009 and will be conducted between the hours of 07:00 and 20:00 at the Victorian Institute of
Sport and the Australian Catholic University, St Patrick’s campus.
I understand that
(a)
(b)
(c)
(d)
(e)
(f)
I am free not to participate if I do not wish to do so and that I am free to withdraw at any time;
I am free to withdraw my consent at any time and withdraw any information supplied by myself;
Withdrawal from this study will not impact on my VIS scholarship;
The project is for the purpose of research and is not for treatment;
The results from this study may be summarized and appear in publications or may be provided to
other researchers in a form that does not identify participants in anyway
Any information I supply will be confidential.
Signed ___________________________________ Date;
(Participant)
_____________________
SIGNATURE OF PRINCIPAL
SUPERVISOR:…………………………………………DATE:……/……/………
SIGNATURE OF STUDENT
RESEARCHER:…………………………………………DATE:…../……./……….
The physical demands of this project remain below those imposed routinely during typical training sessions due to the
controlled environment. In the unlikely event of player injury, please note that contact details for medical staff are
provided below.
Team sports physician: Dr Susan White, Olympic Park Sports Medicine Clinic. Mobile: 0412 304 915 or Office: 9427
0366
Team physiotherapists: Steve Hawkins, Olympic Park Sports Medicine Clinic. Mobile: 0416 078 499 or Office 9427
0366 and Heidi Pollington, Prahran Lifecare Sports Medicine. Mobile: 0409 863 003 or Office: 9529 8899
Sport Psychologist: Steven Bannon, Victorian Institute of Sport. Mobile: 0417 562 221 or Office: 9425 0080
Australian Catholic University Limited A.C.N. 050 192 660
St. Patrick’s Campus115 Victoria Parade, Fitzroy, Victoria 3045, Australia
Mail: Locked bag 4115 Fitzroy MDC 3065, Australia
Telephone 61 3 9953 3041 Facsimile 61 3 9953 3095
71
APPENDIX 3: Assent Form
Assent form for children less than 18 years of age: (Copy 1 – to be retained by Parent)
Name of participant
Date of birth
Gender
I, _____________________________of_______________________________________________
Hereby consent my child ________________________________________________ (name of child) to
participate in the research study on the determination of training speeds for netball to be taken by Dr.
Morgan Williams, Dr. Justin Kemp, Dr. Christian Lorenzen and Nathan Heaney of the Australian Catholic
University. I am aware that as part of the study my child may be asked to perform a VO 2 max test and a test
- retest of the YOYO IR1. The duration of the testing will be approximately 30 minutes per bout, with a test
on 3 separate occasions over a 10-14 day period. The testing is likely to commence on March 1 st 2009 and
will be conducted between the hours of 07:00 and 20:00 at the Victorian Institute of Sport and the
Australian Catholic University, St Patrick’s campus.
I understand that
(a)
(b)
(c)
(d)
(e)
(f)
(g)
My child is free not to participate if he/she does not wish to do so and that he/she is free to
withdraw at any time;
My child is free to withdraw their consent at any time and withdraw any information supplied by
them;
Withdrawal from this study will not impact on their VIS scholarship;
I allow my child to approve or disapprove their assent;
The project is for the purpose of research and is not for treatment;
The results from this study may be summarized and appear in publications or may be provided to
other researchers in a form that does not identify participants in anyway
Any information I supply will be confidential.
NAME OF PARENT/GUARDIAN: ................................................................................................ (block letters)
SIGNATURE OF PARENT/GUARDIAN: ..................................................DATE........../............./...........
NAME OF CHILD: ........................................................................................................................... (block letters)
SIGNATURE OF PRINCIPAL SUPERVISOR:…………………………..DATE........../............./...........
SIGNATURE OF STUDENT RESEARCHER:…………………………..DATE........../............./...........
ASSENT OF PARTICPANTS AGED UNDER 18 YEARS
I ……………………. (the participant aged under 18 years) understand what this research project is
designed to explore. What I will be asked to do has been explained to me. I agree to take part in running
assessments, which will occur over a 30 minute period on three separate occasions over 10 days. I am
aware that I will not be videotaped or audio taped.
NAME OF PARTICPANT AGED UNDER 18: .............................................................................. (block letters)
SIGNATURE: ................................................................................................DATE........../............./...........
SIGNATURE OF PRINCIPAL SUPERVISOR:……………………………DATE........../............./...........
SIGNATURE OF STUDENT RESEARCHER:………………………………DATE........../............./.........
72
The physical demands of this project remain below those imposed routinely during typical
training sessions due to the controlled environment. In the unlikely event of player injury, please
note that contact details for medical staff are provided below.
Team sports physician: Dr Susan White, Olympic Park Sports Medicine Clinic. Mobile: 0412 304
915 or Office: 9427 0366
Team physiotherapists: Steve Hawkins, Olympic Park Sports Medicine Clinic. Mobile: 0416 078
499 or Office 9427 0366 and Heidi Pollington, Prahran Lifecare Sports Medicine. Mobile: 0409
863 003 or Office: 9529 8899
Sport Psychologist: Steven Bannon, Victorian Institute of Sport. Mobile: 0417 562 221 or Office:
9425 0080
73
Assent form for children less than 18 years of age: (Copy 2 – to be retained by Principal Supervisor)
Name of participant
Date of birth
Gender
I, _____________________________of_______________________________________________
Hereby consent my child ________________________________________________ (name of child) to
participate in the research study on the determination of training speeds for netball to be taken by Dr.
Morgan Williams, Dr. Justin Kemp, Dr. Christian Lorenzen and Nathan Heaney of the Australian Catholic
University. I am aware that as part of the study my child may be asked to perform a VO 2 max test and a test
- retest of the YOYO IR1. The duration of the testing will be approximately 30 minutes per bout, with a test
on 3 separate occasions over a 10-14 day period. The testing is likely to commence on March 1st 2009 and
will be conducted between the hours of 07:00 and 20:00 at the Victorian Institute of Sport and the
Australian Catholic University, St Patrick’s campus.
I understand that
(a)
(b)
(c)
(d)
(e)
(f)
(g)
My child is free not to participate if he/she does not wish to do so and that he/she is free to
withdraw at any time;
My child is free to withdraw their consent at any time and withdraw any information supplied by
them;
Withdrawal from this study will not impact on their VIS scholarship;
I allow my child to approve or disapprove their assent;
The project is for the purpose of research and is not for treatment;
The results from this study may be summarized and appear in publications or may be provided to
other researchers in a form that does not identify participants in anyway
Any information I supply will be confidential.
NAME OF PARENT/GUARDIAN: ................................................................................................ (block letters)
SIGNATURE OF PARENT/GUARDIAN: ..................................................DATE........../............./...........
NAME OF CHILD: ........................................................................................................................... (block letters)
SIGNATURE OF PRINCIPAL SUPERVISOR:…………………………….DATE........../............./...........
SIGNATURE OF STUDENT RESEARCHER:……………………………..DATE........../............./...........
ASSENT OF PARTICPANTS AGED UNDER 18 YEARS
I ……………………. (the participant aged under 18 years) understand what this research project is
designed to explore. What I will be asked to do has been explained to me. I agree to take part in running
assessments, which will occur over a 30 minute period on three separate occasions over 10 days. I am
aware that I will not be videotaped or audio taped.
NAME OF PARTICPANT AGED UNDER 18: .............................................................................. (block letters)
SIGNATURE: ................................................................................................DATE........../............./...........
SIGNATURE OF PRINCIPAL
SUPERVISOR:………………………………...DATE........../............./...........
SIGNATURE
OF
RESEARCHER:…………………………………DATE........../............./.........
74
STUDENT
The physical demands of this project remain below those imposed routinely during typical
training sessions due to the controlled environment. In the unlikely event of player injury, please
note that contact details for medical staff are provided below.
Team sports physician: Dr Susan White, Olympic Park Sports Medicine Clinic. Mobile: 0412 304
915 or Office: 9427 0366
Team physiotherapists: Steve Hawkins, Olympic Park Sports Medicine Clinic. Mobile: 0416 078
499 or Office 9427 0366 and Heidi Pollington, Prahran Lifecare Sports Medicine. Mobile: 0409
863 003 or Office: 9529 8899
Sport Psychologist: Steven Bannon, Victorian Institute of Sport. Mobile: 0417 562 221 or Office:
9425 0080
75
APPENDIX 4: Letter of Invitation to Coach/Organisation
TITLE OF PROJECT: Comparison of the VO2 max test and YOYO Intermittent Recovery Test
as a determination of Maximal Aerobic Speed and evaluation of aerobic power
PRINCIPAL SUPERVISOR: Dr. Morgan Williams
STUDENT RESEARCHER: Nathan Heaney
PROGRAM IN WHICH ENROLLED: Exercise Science (Honours)
Dear Sir/Madam
I am writing to inform you of a research study being conducted by the School of Exercise
Science, Australian Catholic University. The research study is looking at two different aerobic
measures – a VO2 max test and the YOYO Intermittent Recovery Test (YOYO IR1). The testing
will commence from the 1st March 2009 and will be performed between the hours of 05:00 and
21:00. The two aerobic measures will each require 30 minutes to complete and the times of
testing will be tailored to suit the schedule of the athletes. The aim of the study is to validate the
use of the YOYO IR1 as an accurate measure of aerobic fitness and to direct aerobic conditioning
through the determination of Maximal Aerobic Speed (MAS).
As part of the study, athletes from the two netball squads; the Melbourne Vixens and Victorian
Fury will be invited to volunteer to take part in this study, As volunteers they will be asked to
complete a VO2 max test at ACU to establish their VO2 max and velocity at VO2 max (vVO2 max)
that will last approximately 15 min. The protocol utilised for the VO2 max test will be adapted to
ensure accurate determination of both VO2 max and vVO2 max. The increments of 0.5km h
increase every minute have been implemented as they are the exact increments utilised during the
YOYO IR1 test and provide an accurate estimation of MAS and vVO2 max.
Subjects will perform a brief warm-up running at 8km h for 3 minutes followed by 2 minutes of
passive recovery where they can perform their own stretching routine before beginning the test.
Subjects will run on a motorised treadmill commencing at a speed of 10km h at a 0% gradient,
with 0.5km h increases every minute until volitional exhaustion. The vVO2 max will be recorded
as the lowest speed at which VO2 max was achieved (Billat & Koralsztein, 1996) or the highest
speed the participant was able to run for at least 30 sec (Smith, Coombes & Geraghty)
Participants will then complete 2 trials of the YOYO IR1 (test – retest) within a 5-7 day period to
establish reliability. The test – retest will be of no inconvenience to the participants as all
assessments will be scheduled into the training program. The YOYO IR1 consists of repeated
20m shuttle runs at increasing speeds, with a 10-second active recovery period between every
2x20m (Thomas, Dawson & Goodman, 2006). During the YOYO IR1 subjects will be removed
from the test when they fail to reach the 20m line before the audio pacing signals on two
consecutive occasions. The speed at the last completed shuttle will be recorded as their Maximal
aerobic speed (MAS). The YOYO IR1 will recorded as a total distance in metres.
Upon completion of the testing, the vVO2 max and MAS data will be collated with comparisons
made to ascertain whether there is a relationship between the two intensity measures. If the MAS
recorded during the YOYO IR1 is similar to the vVO2 max established during the VO2 max test,
76
the YOYO IR1 will be regarded as an accurate means of determining training speeds and
subsequently, directing aerobic conditioning programs.
The aerobic energy system is of paramount importance for intermittent / team sport athletes as it
underpins the development of other integral fitness components for team sport athletes such as
repeat sprint ability (RSA), recovery ability and total work performed during competition.
The knowledge gained from this study will help the athlete, coach and physical preparation staff
with devising more specific, individualised and effective aerobic conditioning programs for the
netball squads at the VIS.
The data collected will be explained to the athlete and coach in detail post-analysis in an
organised interview by one of the researchers. More over, the data collection will not impede or
interfere with the athlete’s normal training regimes as it will be scheduled into the annual plan,
but rather act as a means for increasing our knowledge and gaining additional information, which
can be incorporated into future training programs.
The results obtained will be confidential, but may be published in a scientific journal as
anonymous results from a research study. It is our objective to publish the results of this study in
such a journal.
At any time during the study the parent for those under 18 years of age, child or participant
(those 18 years of age or over) are free to withdraw from the study and all information will
either be returned to you or destroyed. This will not impact on the participants VIS
scholarship status or team selection.
At the end of the study, we will welcome discussion with the athlete/parent on the current level of
fitness in relation to netball. Where there is a concern about the level of fitness we will make
recommendations for the athlete, parent &/or coach to consider.
Should you have any queries or would like to discuss any of the issues raised please contact the
principal supervisor, Mr Morgan Williams on (03) 9953 3420. Please be advised that this study
has been presented to and approved by the University Human Research Ethics Committee at
Australian Catholic University. If at any time parents have a query or complaint about the way
that parent or child has been treated in this study, they may write care of the Office of Research.
Chair, Human Research Ethics Committee
C/o Office of Research
Australian Catholic University
115 Victoria Parade
Fitzroy VIC 3065
Tel: (03) 9953 3157
Fax: (03) 9953 3305
77
Any complaint made will be treated in confidence, investigated fully and the participant informed
of the outcome. Should you agree that athletes/parents within your team may be supplied with
initial recruiting information for the study please phone:
Dr. Morgan Williams
School of Exercise Science (Victoria), Australian Catholic University
03 9953 3041
Your team’s details will be recorded and I will contact you again regarding the timing of the
project. Thank you for your co-operation with this important research.
Yours faithfully,
Dr. Morgan Williams, Principal supervisor.
The physical demands of this project remain below those imposed routinely during typical
training sessions due to the controlled environment. In the unlikely event of player injury, please
note that contact details for medical staff are provided below.
Team sports physician: Dr Susan White, Olympic Park Sports Medicine Clinic. Mobile: 0412 304
915 or Office: 9427 0366
Team physiotherapists: Steve Hawkins, Olympic Park Sports Medicine Clinic. Mobile: 0416 078
499 or Office 9427 0366 and Heidi Pollington, Prahran Lifecare Sports Medicine. Mobile: 0409
863 003 or Office: 9529 8899
Sport Psychologist: Steven Bannon, Victorian Institute of Sport. Mobile: 0417 562 221 or Office:
9425 0080
78