i

Comparison of a YOYO Intermittent Recovery Level 1 test

and 2maxOV 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

ii

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

iii

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 max2OV 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

iv

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.

v

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 max2OV (max2OVv )……………………………………………16

3.2 Maximal Aerobic Speed (MAS)…………………………………………17

3.3 Determining MAS or max2OVv to prescribe HIIT………………………..17

4. Using MAS or max2OVv to prescribe HIIT…………………………………….21

4.1 Benefits of MAS and max2OVv to administer sessions…………………...25

5. Aims of the Study……………………………………………………………..26

6. References……………………………………………………………………..27

vi

CHAPTER 2. JOURNAL SUBMISSION………………………………………….....35

Abstract…………………………………………………………………………..37

Introduction………………………………………………………………………39

Methods…………………………………………………………………………..43

Subjects…………………………………………………………………..43

Methodology……………………………………………………………..37

YOYO IR1 testing protocol...……………………………………………44

max2OV 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

max2OV testing protocol…………………………………………………………..61

Statistical Analysis……………………………………………………………….63

References………………………………………………………………………..64

vii

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

viii

LIST OF TABLES

CHAPTER 2: JOURNAL SUBMISSION

Table 1. max2OV , YOYO-IR1 distance and training speeds for the netball squad

(and for different positions) obtained from the YOYO-IR1 and the max2OV

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

ix

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

1

LITERATURE REVIEW

2

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

3

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

4

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

5

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.

6

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 ( max2OV ),

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 max2OV 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 max2OV

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 max2OV of 47.2 ± 4.3 ml.kg-1

.min-1

. Similarly, Enemark-Miller, Seegmiller

7

and Rana (2009) investigated the maximal oxygen uptake of female NCAA Division 1

lacrosse players whom recorded a mean max2OV of 45.7 ± 4.9 ml.kg-1

.min-1

.

Administering max2OV 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 max2OV 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 max2OV .

Previous research has shown that the UM-TT is both reliable and valid, as evidenced by

its strong correlation with max2OV (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 max2OV ( max2OVv ) 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 max2OV (Billat, 2001; Billat

et al, 2000; Denadi, Oritz, Greco & de Mello, 2006; Dupont, Akakpo & Berthoin, 2004;

8

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

9

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

max2OV (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;

10

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

11

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.

12

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, Ben-

Dov & 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 max2OV enhancement

(Midgley, McNaughton & Wilkinson, 2006; Midgley, McNaughton & Jones, 2007). It is

apparent that max2OV is a product of maximal cardiac output and the maximal arterial-

mixed venous oxygen difference and, therefore, any improvement in either of these

adaptations should result in max2OV 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% max2OV , which

equates to ~80-90% maximum heart rate (Swain et al, 1994). Central adaptations include

13

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 max2OV 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% max2OV as being optimal. This is due to a stroke volume

plateau occurring at 40-50% max2OV and mean arterial pressure at 70-80% max2OV

(MacDougall & Sale, 1981). An initial study by Astrand, Cuddy, Saltin & Stenberg

(1964) suggested that stroke volume plateaus at around 40-75% max2OV , and as exercise

intensity approaches max2OV , stroke volume may even decrease. However, recent studies

using well trained individuals suggest the opposite actually occurs. As exercise intensity

approaches max2OV , stroke volume and both systolic and mean arterial blood pressures

increase (Gledhill, Cox & Jamnick, 1994; Zhou et al, 2001).

14

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 max2OV (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

max2OV (Midgley, McNaughton & Wilkinson, 2006).

Conversely, peripheral adaptations occur as exercise intensity increases to greater than

80% max2OV 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,

15

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

16

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 max2OV (

max2OVv ) and maximal aerobic speed (MAS).

3.1 Velocity at max2OV (max2OVv )

The term max2OVv was introduced by Daniels & Scardina (1984) and can be defined as

the minimal velocity associated with max2OV determined by an incremental treadmill test.

The parameter max2OVv combines both

max2OV 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 max2OVv can explain differences in

17

performance that max2OV or running economy used in isolation do not (Billat &

Koralsztein, 1996).

The max2OVv 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 (UM-

TT), 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 max2OVv to prescribe high intensity interval training

(HIIT)

Using MAS or max2OVv 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

18

max2OVv (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 max2OVv ,

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 max2OVv

. 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

max2OV ( max2OVv ) 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.

19

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 max2OVv 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 max2OV 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 UM-

TT 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

20

training speeds when compared to max2OVv 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.

21

4. Using MAS or max2OVv 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 max2OV 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 max2OV (Fox, Bartels & Billings, 1973).

It has been recommended that to improve an athlete’s max2OV , exercise intensity should

be at, or near, max2OV 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 max2OV in well trained distance

runners despite a 10% reduction in running volume. This improvement was attributed to

the inclusion of training at 90-100% max2OV . Numerous other studies involving well

trained distance runners and training intensities of 90-100% max2OV 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.

22

In order to maximise the total amount of time and/or work performed at or near max2OV ,

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 max2OVv , which equates to an intensity of 90-95%

max2OVv . Astrand investigated the efficacy of 3 minute runs at 90-92%

max2OVv and

established that max2OV 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

max2OVv interspersed with 10 seconds passive recovery and resulted in max2OV being

obtained along with low blood lactate accumulation. These pioneering studies highlighted

the efficacy of using contrasting interval training protocols to elicit improvements in

max2OV and, subsequently result in performance improvements. Undoubtedly, the

23

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 max2OVv 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 max2OV by using MAS or max2OVv

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 max2OV 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 max2OVv ) to an

24

interval training protocol which consisted of 30 s work at 100% max2OVv and 30 s active

recovery at 50% max2OVv

.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 max2OV (interval = 7 min 51 s at

max2OV versus continuous = 2 min 42 s at max2OV ).

Intensities above MAS and/or max2OVv

have also been shown to be effective when trying

to elicit improvements in max2OV .A study by Dupont et al (2002) compared the time

spent at a high level of 2OV in a continuous run at 100% max2OVv and short intermittent

runs consisting of 15 s work at a range of supramaximal intensities (110%, 120%, 130%

and 140% max2OVv ) 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% max2OV , 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% max2OV .

However, when you take into account time to exhaustion (tlim) at each intensity, and then

look at time spent at max2OV 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

25

most the effective 2OV stimulus with 58% of the 374 ± 234 s tlim spent at max2OV . 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 max2OV for as long as

possible and, subsequently, for improving max2OV when compared to continuous type

training methods.

4.1 Benefits of MAS and max2OVv to administer sessions

When devising and administering conditioning programs, utilising MAS or max2OVv 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

26

considered when prescribing conditioning (e.g. percentage of maximal heart rate), both

MAS and max2OVv 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 max2OVv obtained from a max2OV (graded treadmill) test, and (2) assess the

strength of the relationship between these two aerobic measures (i.e. YOYO IR1 &

max2OV ). 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.

27

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35

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.

36

VALIDITY OF AEROBIC FITNESS MEASURES IN

NETBALLERS AND DETERMINATION OF TRAINING

SPEEDS FOR TRAINING AND TESTING

Submission Type: Original Investigation

NATHAN E. HEANEY

37

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 ( max2OV ) 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 max2OV and YOYO-IR1 tests on separate occasions. The derived

training speed variables used in this study included: velocity at max2OV ( max2OVv ),

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 max2OV ; as well as between derived training speeds. However, the YOYO IR1

derived training speeds were both significantly faster when compared to max2OVv . 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 max2OVv , it is recommended that practitioners be cautious.

38

KEY WORDS

YOYO Intermittent Recovery Test, Maximal Aerobic Speed, Velocity at max2OV ,

High Intensity Interval Training, Aerobic Conditioning Prescription

39

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 (max2OV ) techniques. It can be measured indirectly from ventilatory data,

which is generally laboratory-based, or, more commonly, estimated using performance-

based field testing. Once max2OV has been obtained, parameters such as velocity at

max2OV ( max2OVv ) 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 max2OVv concept was introduced by Daniels and Scardina (5)

and can be defined as

the minimal velocity associated with max2OV 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 (7,8)

. Both max2OVv and MAS are utilised to quantify training intensity,

particularly in the prescription of high-intensity interval training (HIIT). The application

of HIIT using MAS and/or max2OVv as the intensity measure for aerobic conditioning has

40

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 max2OVv 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 max2OVv

are stable and less influenced by external factors such as heat, humidity, dietary intake

and hydration (10)

.

Using MAS or max2OVv to prescribe training has clear benefits, although obtaining

max2OVv

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 max2OVv (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

41

cannot be used interchangeably with max2OVv (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 max2OVv . 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

42

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 YOYO-

IR1 test and max2OV in state-level netballers. By comparing the laboratory-based max2OVv

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 max2OV test would be strongly related.

43

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 YOYO-

IR1 test was completed on a sprung wooden floor and scheduled as part of the aerobic

conditioning program. The second session involved the max2OV 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.

44

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 YOYO-

IR1 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.

45

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)

.

max2OV 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.

max2OV was considered to be achieved when two of the following criteria were met:

46

(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 (220-

age) (12)

.

The max2OVv was recorded as the lowest speed at which max2OV 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 max2OVv .

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 Shapiro-

Wilks 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.

47

RESULTS

In the laboratory, a mean max2OV of 45.3. ± 5.6 ml.kg-1

.min-1

(min max2OV = 36.5 ml.kg-

1.min

-1, max max2OV = 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 max2OV

(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 max2OVv (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 max2OVv . 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 max2OVv . 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

).

48

1750150012501000750

YOYOIR1 (m)

50.00

45.00

40.00

VO

2m

ax (

ml.kg

.min

)

Fit line for Total

MID

GS

GK

POSITIONS

R Sq Linear = 0.934

Figure 1: Linear regression of YOYO-IR1 total distance and max2OV for the entire squad

of female Netballers

As expected, the midcourt players performed better than the goal keepers and goal

shooters in both the max2OV and YOYO-IR1 test; and as such recorded faster estimated

training speeds.

49

Table 1: max2OV , YOYO-IR1 distance and training speeds for the netball squad (and for

different positions) obtained from the YOYO-IR1 and the max2OV test

max2OVv

(ml.kg-

1.min

-1)

YOYO-

MAS

(m)

max2OVv

(m·s-1

)

YOYO-

MAS

(m·s-1

)

YOYO-MAS

Equation

(m·s-1

)

Squad

(n = 10) 44.9 ± 5.7 1432 ± 431 4.27 ± 0.26 4.35 ± 0.09 4.42 ± 0.11

Goal Keepers

(n = 3) 44.06 ± 4.29 1313 ± 243 4.26 ± 0.20 4.35 ± 0.09 4.42 ± 0.11

Mid Court

(n = 5) 49.45 ± 1.68 1784 ± 10 4.44 ± 0.22 4.58 ± 0.00 4.62 ± 0.02

Goal Shooters

(n = 2) 36.9 ± 0.57 740 ± 0 3.96 ± 0.10 4.10 ± 0.10 4.17 ± 0.01

Despite the fact that both YOYO-IR1 derived training speed were significantly faster

than max2OVv , there was still a moderately strong correlation between all the training

speed variables (Table 2).

50

Table 2: Pearson’s correlation coefficient for training speeds

max2OVv

(m·s-1

)

YOYO-MAS

(m·s-1

)

YOYO-MAS

Equation (m·s-1

)

max2OVv

(m·s-1

)

1 0.826 0.808

YOYO-MAS

(m·s-1

)

0.826 1 0.980

YOYO-MAS

Equation (m·s-1

) 0.808 0.980 1

From our regression model that included the YOYO-IR1 distance, max2OVv was

adequately predicted (R2 = 0.665). The derived equation 1 was a good fit and as follows:

max2OVv (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 max2OV 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

51

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

state level hockey players (18)

. Similarly, the mean max2OV of 44.9 ± 5.7 ml.kg-1

.min-1

(min

= 36.5 ml.kg-1

.min-1

, max max2OV = 51.3 ml.kg-1

.min-1

) also compares well with other

female team sport athletes. A mean max2OV of 47.2 ± 4.3 ml.kg-1

.min-1

was recorded for

under 20 female soccer players (20)

; whilst a mean max2OV 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 max2OV of 45.7 ± 4.9 ml.kg-1

.min-1

was reported for a NCAA Division 1

women’s lacrosse team (22)

. These YOYO-IR1 and max2OV results add credence to the

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 max2OV 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 max2OV and YOYO IR1 scores reflective of this. More specifically, the

goal shooters recorded lesser max2OV and YOYO IR1 values when compared to the goal

keepers. This disparity could potentially be attributed to the goal keepers in this study

52

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 max2OV (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

max2OVv 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 max2OVv obtained via the max2OV test. Therefore, the direct

derivatives of MAS from the YOYO-IR1 should not be used interchangeably with

max2OVv . 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.

53

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 max2OVv / MAS guided interval training. Findings from this

investigation suggest that for netballers, MAS derived from YOYO-IR1 and YOYO-

MAS equation is over estimated compared to max2OVv , 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 max2OVv ,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 max2OVv of 4.58

54

m•s-1

and is prescribed 30 sec intervals at max2OVv , 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 max2OVv 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 max2OVv 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.

55

REFERENCES:

1. Tomlin D, L and Wegner, H, A. The Relationship between Aerobic Fitness and

Recovery from High Intensity Intermittent Exercise. Sports Medicine. 2001;31:1-

11.

2. 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.

3. Billat VL, Koralsztein JP. Significance of the velocity at VO2max and time to

exhaustion at this velocity. Sports Medicine 1996;22:90-108.

4. 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.

5. Daniels J, Scardina N. Interval training and performance. Sports Medicine

1984;1:327-334.

6. Billat VL. Interval Training for Performance: Part 1 - Aerobic Interval Training

Sports Medicine 2001;31:13-31.

7. 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.

8. 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;4:408-

411.

9. 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.

10. Achten J, Jeukendrup A. Heart Rate Monitoring: Applications and Limitations.

Sports Medicine. 2003;33:22.

11. 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.

12. 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.

13. 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.

14. 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.

56

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;8:1-

17.

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.

57

EXTENDED METHODOLOGY

58

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 max2OV test and was completed within a two-

week 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.

59

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.

60

Table 1: Number of shuttles, speed and distance completed for each YOYO IR1 level

YOYO IR1 Level

Number of Shuttles

Per Level

Speed

(km·h-1

).

Distance Completed

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;

61

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).

max2OV 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

62

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.

max2OV was considered to be achieved when two of the following criteria were met:

(1) volitional exhaustion, (2) plateau in 2OV 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 max2OVv was recorded as the lowest speed at which max2OV 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 max2OVv .

63

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 Shapiro-

Wilks 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.

64

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:

65

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.

66

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, 337-

343.

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.

67

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 1

st 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

68

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

69

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

70

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 VO2 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) I am free not to participate if I do not wish to do so and that I am free to withdraw at any time;

(b) I am free to withdraw my consent at any time and withdraw any information supplied by myself;

(c) Withdrawal from this study will not impact on my VIS scholarship;

(d) The project is for the purpose of research and is not for treatment;

(e) 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

(f) 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

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 VO2 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) I am free not to participate if I do not wish to do so and that I am free to withdraw at any time;

(b) I am free to withdraw my consent at any time and withdraw any information supplied by myself;

(c) Withdrawal from this study will not impact on my VIS scholarship;

(d) The project is for the purpose of research and is not for treatment;

(e) 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

(f) 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

72

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 VO2 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) 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;

(b) My child is free to withdraw their consent at any time and withdraw any information supplied by

them;

(c) Withdrawal from this study will not impact on their VIS scholarship;

(d) I allow my child to approve or disapprove their assent;

(e) The project is for the purpose of research and is not for treatment;

(f) 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

(g) 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........../............./.........

73

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

74

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 VO2 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) 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;

(b) My child is free to withdraw their consent at any time and withdraw any information supplied by

them;

(c) Withdrawal from this study will not impact on their VIS scholarship;

(d) I allow my child to approve or disapprove their assent;

(e) The project is for the purpose of research and is not for treatment;

(f) 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

(g) 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........../............./.........

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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

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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 1

st 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,

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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

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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