Time-motion analysis has been used extensively to

INFLUENCE OF THE OPPOSING TEAM ON THE PHYSICAL DEMANDS OF ELITE RUGBY LEAGUE MATCH PLAY TIM J. GABBETT 1,2 1 School of Exercise Science, Australian Catholic University, Brisbane, Australia; and 2 School of Human Movement Studies, The University of Queensland, Brisbane, Australia ABSTRACT Gabbett, TJ. Influence of opposing team on physical demands of elite rugby league match play. J Strength Cond Res 27(6): 1629 1635, 2013 This study investigated influence of playing standard, and winning and losing on physical demands of elite rugby league match play. Twenty-two elite rugby league players participated in this study. Global positioning system data were collected during 16 rugby league matches. Players covered significantly greater (p # 0.05) absolute and relative distance at high speeds when playing against Bottom 4 teams than when competing against Top 4 teams. The total distance per minute of match play and relative distance at low speeds were greater when matches were won. In addition, a greater absolute and relative number of maximal accelerations and repeated high-intensity effort bouts were performed when players were competing in winning teams than in losing teams. The mean and maximum number of efforts in a repeated high-intensity effort bout was also higher in winning teams, although recovery between efforts was shorter in losing teams. Moderate (7 17 points) and large ($18 points) winning margins were associated with greater relative distances covered and distances covered at low speeds than small winning margins. No meaningful differences were found in physical demands between small, moderate, and large losing margins. The results of this study demonstrate that physical demands of rugby league are greater when winning than losing, and when competing against lower ranked teams. Furrmore, larger winning margins are associated with greater physical demands than small and moderate winning margins, with se physical demands, in turn, greater than losing margins of any magnitude. These findings suggest that competitive advantage of successful elite rugby league teams is closely linked to ir ability to maintain a higher playing intensity than ir less successful counterparts. KEY WORDS playing standard, activity profiles, GPS, physical preparation Address correspondence to Dr. Tim J. Gabbett, tim_gabbett@yahoo. com.au. 27(6)/1629 1635 Ó 2013 National Strength and Conditioning Association INTRODUCTION Time-motion analysis has been used extensively to study physical demands and movement patterns of team sports (1,5,8). However, despite popularity of sport, studies describing physical demands of rugby league are limited, with time-motion analyses restricted to a few studies spanning for a period of 20 years. In early 1990s, Meir et al. (17) performed first timemotion analysis of professional rugby league players. Describing a total of 20 movements and game-specific events, se authors reported that players covered between 6,500 and 7,900 m during course of a game, depending on playing position. More recently, researchers have studied highintensity running (14,22,23), sprinting (13), tackling (4,14), ball-in-play (12), and repeated high-intensity effort demands (3,13,14) of elite rugby league competitions. Results of timemotion analysis studies have provided important information to applied sport scientists and strength and conditioning coaches to assist in development of game-specific conditioning programs. Previous studies of team sport athletes (e.g., soccer) have shown that elite players typically (but not always) perform more high-intensity running than sub-elite competitors (18), when demands of competition are greatest (1). Rampinini et al. (21) investigated physical demands of most and least successful teams competing in Italian Serie A league and found that most successful teams covered greater total distances with ball, and more high-intensity and very high intensity running with ball. Andersson et al. (1) showed that amount of high-intensity running performed by female soccer players was greater in international than domestic matches. These findings have been confirmed by ors (15) who demonstrated that female soccer players performed more repeated-sprint bouts in international matches (4.8 bouts per match) than national (1.0 bout per match) and domestic (1.4 bouts per match) matches. However, although physical demands of team sport competition have been shown to increase with playing standard, results are equivocal with some studies demonstrating lower playing intensity as competitive standard increases (8). One method of investigating physical demands of different playing standards is to study movement patterns of best and worst teams in same competition (8,20). VOLUME 27 NUMBER 6 JUNE 2013 1629

Physical Demands of Winning and Losing in Rugby League Figure 2. Rugby league player wearing minimaxx global positioning system unit. Figure 1. MinimaxX global positioning system unit used in this study. Di Salvo et al. (8) investigated high-intensity running activity of elite soccer players competing in English Premier League and found that teams finishing in bottom 5 (919 6 128 m) and middle 10 (917 6 143 m) league positions completed significantly more total high-intensity running than teams in top 5 league positions (885 6 113 m) (8). Using a slightly different approach, Rampinini et al. (20) studied physical demands of one professional soccer team and analyzed influence of opposing team on match performance. In direct contrast to findings of Di Salvo et al. (8), total distance covered and distance covered in high-intensity running was higher when competing against best teams compared with worst teams. Clearly, furr studies are required to better understand relationship between physical match performance and playing standard. The Australian National Rugby League (NRL) competition is widely regarded as best rugby league competition in world. Anecdotal evidence suggests that competitive advantage of best NRL teams is closely linked to ir ability to maintain a higher playing intensity than less successful teams. However, to date, no study has investigated if matches involving best NRL teams are associated with higher playing intensities than matches involving worst NRL teams and wher winning is associated with higher or lower physical demands than losing. With this in mind, purpose of this study was to investigate if higher standard NRL matches were associated with greater physical demands than lower standard NRL matches. The influence of playing standard and winning and losing on physical demands of competition were analyzed by comparing (a) activity profiles of players competing against high-ranked (Top 4) and low-ranked (Bottom 4) teams and (b) activity profiles of players when ir team eir won or lost. METHODS Experimental Approach to Problem The physical demands of elite rugby league matches were investigated using a prospective case series experimental design. Global positioning system (GPS) data were collected over an NRL season and were analyzed by comparing activity profiles of players competing against high-ranked (Top 4) and low-ranked (Bottom 4) teams, and when ir team eir won or lost. Differences among matches of various competitive standing were compared using Cohen s 1630

www.nsca.com TABLE 1. Physical and perceptual demands of elite rugby league match play when competing against Top 4 and Bottom 4 teams.* Top 4 Bottom 4 Effect size Time (min) 60.9 6 4.4 67.4 6 4.4 0.30 Total distance (m) 6,144.2 6 457.9 6,795.7 6 469.8 0.28 Relative distance (m$min 21 ) 101.2 6 2.5 102.2 6 4.0 0.06 Low speed Distance (m) 5,863.4 6 432.4 6,405.8 6 449.0 0.25 Relative distance (m$min 21 ) 97.1 6 2.8 96.5 6 4.1 0.03 High speed Distance (m) 300.6 6 31.6 393.3 6 36.9 0.55 Relative distance (m$min 21 ) 4.7 6 0.3 5.7 6 0.4 0.57 Accelerations Maximal accelerations (n) 79.5 6 8.0 75.8 6 7.4 0.10 Maximal accelerations (n$min 21 ) 1.3 6 0.1 1.2 6 0.1 0.18 Collisions Mild collisions (n) 0.4 6 0.1 0.4 6 0.1 0.05 Relative mild collisions (n$min 21 ) 0.01 6 0.01 0.01 6 0.01 0.00 Moderate collisions (n) 6.9 6 1.2 7.3 6 1.0 0.08 Relative moderate collisions (n$min 21 ) 0.13 6 0.02 0.12 6 0.02 0.11 Heavy collisions (n) 10.3 6 1.1 10.5 6 0.8 0.04 Relative heavy collisions (n$min 21 ) 0.18 6 0.02 0.16 6 0.01 0.28 Total collisions (n) 17.6 6 1.9 18.2 6 1.5 0.07 Relative total collisions (n$min 21 ) 0.31 6 0.03 0.29 6 0.02 0.00 Repeated high-intensity efforts Bouts (n) 12.5 6 1.3 12.0 6 1.2 0.08 Efforts per bout (n) 4.1 6 0.2 4.1 6 0.2 0.00 Maximum efforts per bout (n) 6.7 6 0.6 6.3 6 0.8 0.12 Mean effort duration (s) 0.9 6 0.1 1.0 6 0.1 0.39 Maximum effort duration (s) 4.6 6 0.2 4.6 6 0.2 0.00 Effort recovery (s) 6.7 60.4 6.5 6 0.2 0.14 Bout frequency 1 every 6.8 min 1 every 7.0 min 0.06 Rating of perceived exertion (au) 8.5 6 0.2 7.9 6 0.2 0.66 *Data are mean 6 SE. Significant differences (p # 0.05) between Top 4 and Bottom 4 teams. Effect sizes of,0.09, 0.10 0.49, 0.50 0.79, and.0.80 considered trivial, small, moderate, and large, respectively. effect size (ES) statistic (7). It was hyposized that meaningful differences in activity profiles would exist among best and worst teams, with physical demands being greatest when playing higher ranked teams. Furrmore, it was hyposized that intensity of matches would be greater in winning than losing teams. Subjects Twenty-two NRL players (mean 6 SE, aged 23.6 6 0.5 years) participated in this study. All participants received a clear explanation of study, including information on risks and benefits, and written consent was obtained. All experimental procedures were approved by Institutional Review Board for Human Investigation. Global Positioning System Analysis Global positioning system analysis was completed during 16 NRL matches. Movement was recorded by a minimaxx GPS unit (Team 2.5; Catapult Innovations, Melbourne, Australia) sampling at 5 Hz (Figure 1). The GPS signal provided information on speed, distance, position, and acceleration. The GPS unit also included triaxial accelerometers and gyroscopes sampling at 100 Hz, to provide information on physical collisions and repeated high-intensity efforts. The unit was worn in a small vest on upper back of players (Figure 2). Data were categorized into (a) movement speed bands, corresponding to low (0 5 m$s 21 ) and high (. 5m$s 21 ) speeds (14); (b) maximal accelerations ($2.79 m$s 22 ) (2); (c) mild, moderate, and heavy collisions (11); and (d) repeated high-intensity effort bouts (14). A repeated high-intensity effort bout was defined as 3 or more maximal acceleration, high speed, or contact efforts with,21 seconds recovery between efforts (13,14). The minimaxx units have been shown to have acceptable validity and reliability (19). VOLUME 27 NUMBER 6 JUNE 2013 1631

Physical Demands of Winning and Losing in Rugby League TABLE 2. Influence of winning and losing on physical and perceptual demands of elite rugby league match play.* Match won Match lost Effect size Time (min) 62.0 6 3.9 60.2 6 3.6 0.08 Total distance (m) 6,542.9 6 417.5 5,956.8 6 340.0 0.26 Relative distance (m$min 21 ) 107.9 6 3.5 100.5 6 2.7 0.40 Low speed Distance (m) 6,245.0 6 398.2 5,610.6 6 318.2 0.30 Relative distance (m$min 21 ) 103.4 6 3.6 94.9 6 2.6 0.46 High speed Distance (m) 312.5 6 28.0 348.3 6 29.5 0.20 Relative distance (m$min 21 ) 5.0 6 0.3 5.7 6 0.4 0.32 Accelerations Maximal accelerations (n) 91.7 6 7.1 71.4 6 5.5 0.54 Maximal accelerations (n$min 21 ) 1.6 6 0.1 1.3 6 0.1 0.50 Collisions Mild collisions (n) 0.4 6 0.1 0.3 6 0.1 0.16 Relative mild collisions (n$min 21 ) 0.01 6 0.01 0.01 6 0.01 0.00 Moderate collisions (n) 6.6 6 0.8 7.7 6 0.9 0.21 Relative moderate collisions (n$min 21 ) 0.13 6 0.02 0.14 6 0.16 0.10 Heavy collisions (n) 10.9 6 0.9 10.1 6 0.8 0.16 Relative heavy collisions (n$min 21 ) 0.19 6 0.02 0.17 6 0.19 0.23 Total collisions (n) 17.9 6 1.6 18.1 6 1.5 0.02 Relative collisions (n$min 21 ) 0.3 6 0.1 0.3 6 0.1 0.00 Repeated high-intensity efforts Bouts (n) 13.9 6 1.1 11.4 6 0.9 0.42 Efforts per bout (n) 4.5 6 0.2 4.1 6 0.2 0.40 Maximum efforts per bout (n) 7.9 6 0.7 6.2 6 0.4 0.51 Mean effort duration (s) 0.9 6 0.1 1.0 6 0.1 0.39 Maximum effort duration (s) 4.8 6 0.2 4.6 6 0.2 0.17 Effort recovery (s) 7.1 6 0.2 6.4 6 0.2 0.50 Bout frequency 1 every 7.1 min 1 every 6.7 min 0.14 Rating of perceived exertion (au) 8.4 6 0.2 8.2 6 0.2 0.23 *Data are mean 6 SE. Significant differences (p # 0.05) between matches won and lost. Effect sizes of,0.09, 0.10 0.49, 0.50 0.79, and.0.80 considered trivial, small, moderate, and large, respectively. In addition, minimaxx units have been shown to offer a valid measurement of tackles and repeated efforts commonly observed in collision sports (11). Players also provided a rating of ir perceived effort during individual matches using a modified rating of perceived exertion scale (10). Perceptions of effort estimates were obtained 30 minutes after completing match. Statistical Analyses Differences in physical demands between high-ranked (i.e., Top 4) and low-ranked (Bottom 4), and winning and losing teams were compared using statistical significance testing and by using a practical approach based on real-world relevance of results (6). First, differences in physical demands (i.e., distance covered at low and high speeds; mild, moderate, and heavy collisions; and repeated high-intensity effort activity) between Top 4 and Bottom 4 teams, and winning and losing teams were compared using an independent t-test. The level of significance was set at p # 0.05, and all data are reported as mean 6 SE. Second, given practical nature of study, differences in demands between Top 4 and Bottom 4 teams, and winning and losing teams were also analyzed using Cohen s ES statistic (7). Effect sizes of,0.09, 0.10 0.49, 0.50 0.79, and.0.80 were considered trivial, small, moderate, and large, respectively (7). RESULTS The physical demands of elite rugby league match play when competing against Top 4 and Bottom 4 teams are shown in Table 1. Players covered significantly greater (p # 0.05, ES = 0.55 0.57) absolute and relative distance at high speeds when playing against Bottom 4 teams than when competing against Top 4 teams. The number of mild, moderate, and heavy collisions were similar (p. 0.05, ES = 0.00 0.28) wher competing against Top 4 or Bottom 4 teams. The physical demands of competition were greatest when matches were won (Table 2). Players covered significantly 1632

www.nsca.com Figure 3. Physical and perceptual demands of elite rugby league match play with a small (#6 points), moderate (7 17 points), and large ($18 points) winning or losing margin. Data are mean 6 SE. Effect sizes (ES) represent magnitude of difference between smallest and largest values. Effect sizes of,0.09, 0.10 0.49, 0.50 0.79, and.0.80 considered trivial, small, moderate, and large, respectively. greater (p # 0.05) total distance per minute of match play (ES = 0.40) and greater relative distance at low speeds (ES = 0.46) when matches were won. In addition, a greater absolute (ES = 0.54) and relative (ES = 0.50) number of maximal accelerations, and repeated high-intensity effort bouts were performed when players were competing in winning teams than in losing teams. The mean and maximum number of efforts in a repeated high-intensity effort bout was also higher in winning teams (ES = 0.40 0.51), although recovery between efforts was significantly shorter (p # 0.05, ES = 0.50) in losing teams. No significant differences (p. 0.05, ES = 0.00 0.23) were found between winning and losing teams for number of mild, moderate, and heavy collisions. Moderate (7 17 points) and large ($18 points) winning margins were associated with greater relative distances covered and distances covered at low speeds than small winning margins. Ratings of perceived exertion were lower when teams won by large margins and higher when teams lost by large margins (Figure 3). DISCUSSION This study investigated influence of playing standard and winning and losing on physical demands of elite rugby league match play. The results of this study demonstrate that physical demands of rugby league are greater when winning than when losing and when competing against lower ranked teams. Furrmore, larger winning margins are associated with greater physical demands than small and moderate winning margins, with se physical demands, in turn, greater than losing margins of any magnitude. These findings suggest that competitive advantage of successful NRL teams is closely linked to ir ability to maintain a higher playing intensity than ir less successful counterparts. This study found greater physical demands in winning than losing teams. Players from winning teams covered greater total distances per minute of match play, including greater distances at low speeds. However, no significant differences were found between winning and losing teams for amount of high-speed running performed. These findings demonstrate that although winning and losing teams are equally able to perform high-intensity running demands of competition, winning teams are better able to maintain a higher intensity during recovery from se high-speed efforts. Players from winning teams performed more maximal accelerations and a greater number and intensity of repeatedeffort bouts. Although distances covered at low and high speeds are important to elite rugby league players, VOLUME 27 NUMBER 6 JUNE 2013 1633

Physical Demands of Winning and Losing in Rugby League previous studies have emphasized importance of repeated high-intensity effort ability to competitive success in this sport (3,13,14,16). We have recently shown that players perform, on average, 9 6 1 repeated high-intensity effort bouts per game (13). Furrmore, recent evidence has shown that majority (approximately 70%) of tries scored occur in close proximity to a repeated high-intensity effort bout (3), lending support to suggestion that ability (or inability) to perform se activities could prove critical to outcome of game. These findings have also received support from work of ors (16) who demonstrated that repeated high-intensity effort exercise (involving sprinting and tackling) was associated with higher heart rate and perceived exertion, and greater reductions in sprinting performance than repeated sprinting in isolation. Collectively, present and previous (3,13,16) findings demonstrate importance of repeated high-intensity effort ability to both performance and fatigue tolerance in elite rugby league players. Perhaps more importantly, this study is first to demonstrate importance of repeated highintensity effort ability to competitive success in elite rugby league. While few differences in physical demands existed between Top 4 and Bottom 4 teams, in contrast to our hyposis, this study found greater absolute and relative amounts of highspeed running when players were competing against lower ranked teams. A possible confounding influence in this finding is that physical demands were greater when teams were winning, and by nature of ir ladder position, lower ranked teams lose more regularly. Although it is possible that lowranked teams may be required to increase playing intensity when competing against higher ranked teams, we are more circumspect in our interpretation of this finding. Indeed, losing teams are likely to be required to perform more defense, and cover-defend against a greater number of line breaks and tackle breaks. It is plausible that poorer match performance of losing teams results in a greater amount of scrambling in defense, which in turn, increases amount of high-speed running performed in competition. Players covered greater total distance when team won by large margins; however, this increased total distance was accomplished predominantly through increases in amount of low-intensity activity performed. There were only small differences (ES = 0.38) in high-speed running when matches were won by small (#6 points), moderate (7 17 points), or large ($18 points) margins. However, although insignificant differences were found between small, moderate, and large losing margins for total distance and distance covered at low speeds, greater distance was covered at high speeds when teams lost by large margins. These findings provide furr support for suggestion that performing large amounts of defense may increase highspeed running demands of elite rugby league match play. To date, only one study has documented physical demands of attack and defense in elite rugby league players, with this study finding higher work rates in majority of positions when attacking than defending (23). Clearly, furr studies examining physical demands of rugby league attack and defensive play, with particular reference to field position, may provide important data to inform rugby league strength and conditioning programs. Although physical demands were greater when winning than losing, and when competing against lower ranked teams, player s perceptions of those demands were greatest when competing against higher ranked teams. Furrmore, although larger winning margins were associated with greater physical demands than small and moderate winning margins, perceptions of effort were greater with smaller winning margins and larger losing margins. Collectively, se results suggest an uncoupling of physical and perceptual demands of elite rugby league match play. In addition, se findings suggest that matches against Top 4 teams, and with small winning margins and large losing margins, provide greater psychological stress than matches against lower ranked teams, or when winning by a large margin and losing by a small margin. Previous investigations of professional rugby league match play have shown an association between number of collisions performed and amount of muscle soreness, muscle damage (as estimated from creatine kinase concentration), perceptual fatigue, and neuromuscular fatigue (as measured via a counter movement jump) experienced by players (24). Although degree of muscle damage sustained in competition was not a specific purpose of this study, it is possible that losing teams sustained greater muscle damage as a consequence of physical dominance of winning teams. Furr studies investigating influence of winning and losing on markers of perceptual fatigue, muscle soreness, muscle damage, and neuromuscular fatigue are warranted. In conclusion, this study investigated influence of playing standard and winning and losing on physical demands of elite rugby league match play. The results of this study demonstrate that physical demands of rugby league are greater when winning than losing and when competing against lower ranked teams. Furrmore, larger winning margins are associated with greater physical demands than small and moderate winning margins, with se physical demands, in turn, greater than losing margins of any magnitude. These findings suggest that competitive advantage of successful NRL teams is closely linked to ir ability to maintain a higher playing intensity than ir less successful counterparts. PRACTICAL APPLICATIONS This study provides important information that can be applied by sport scientists and strength and conditioning coaches involved in physical preparation of elite rugby league teams. First, physical demands (e.g., distance covered, maximal accelerations, and repeated high-intensity effort performance) of winning teams were significantly greater than losing teams, and also greater than previously reported for professional rugby league players (14,25). These findings suggest that physical conditioning programs designed to prepare 1634

www.nsca.com players to compete in elite rugby league matches may differ from programs designed to win elite rugby league matches. It is likely that preparing players for average demands of competition may result in players being under-prepared for most demanding passages of play (14). Equally, given differences in physical demands between winning and losing teams, preparing players for average demands of competition may result in m being unable to perform greater demands associated with winning matches. Second, whereas repeated high-intensity effort activity (in form of sprinting and tackling) has been shown to result in greater physiological stress and fatigue than repeated sprinting in isolation (16), this study also demonstrates important contribution that this quality makes to competitive success. The use of game-specific repeatedeffort conditioning that involves rapid accelerations, sprinting, and collisions, and short recovery periods, is likely to improve repeated high-intensity effort ability and ultimately competitive performances. Third, winning teams were better able to maintain intensity in recovery periods between high-speed running efforts. Whereas previous studies have shown that use of active recovery between high-intensity training efforts results in reduced training performance than passive recovery (9), se findings suggest that conditioning coaches may benefit from manipulating intensity of recovery in training. The use of high-intensity interval (e.g., maximal aerobic speed) training that involves a moderate-intensity recovery period between high-intensity efforts may condition players to maintain a higher pacing strategy during competition than if passive recovery alone was used between efforts. Finally, player s perceptions of competitive demands were greatest when competing against Top 4 teams and when winning by small margins and losing by large margins. From a practical perspective, se findings could be used by applied sport scientists and strength and conditioning staff to provide insight into subsequent physical conditioning and recovery practices. It is likely that after matches against higher ranked teams, players will experience greater perceptual fatigue, and refore require greater recovery than when competing against lower ranked teams. Similarly, larger winning margins and smaller losing margins were associated with lower perceptions of effort, and presumably reduced perceptual fatigue. If adequate recovery time between matches is available, additional conditioning may be beneficial following se matches associated with lower psychological stress. REFERENCES 1. Andersson, HA, Randers, MB, Heiner-Moller, A, Krustrup, P, and Mohr, M. Elite female soccer players perform more high-intensity running when playing in international games compared with domestic league games. J Srength Cond Res 24: 912 919, 2010. 2. Aughey, RJ. Australian football player work-rate: Evidence of fatigue and pacing? Int J Sports Physiol Perform 5: 394 405, 2010. 3. Austin, D, Gabbett, T, and Jenkins, D. Repeated high-intensity exercise in professional rugby league. J Strength Cond Res 25: 1898 1904, 2010. 4. Austin, D, Gabbett, T, and Jenkins, D. Tackling in professional rugby league. J Strength Cond Res 25: 1659 1663, 2011. 5. Bangsbo, J, Norregaard, L, and Thorso, F. Activity profile of competition soccer. Can J Sport Sci 16: 110 116, 1991. 6. Batterham, AM and Hopkins, WG. Making meaningful inferences about magnitudes. Int J Sports Physiol Perform 1: 50 57, 2006. 7. Cohen, J. Statistical Power Analysis for Behavioural Sciences (2nd ed.). New York, NY: Academic Press, 1988. 8. Di Salvo, V, Gregson, W, Atkinson, G, Tordoff, P, and Drust, B. Analysis of high intensity activity in Premier League soccer. Int J Sports Med 30: 205 212, 2009. 9. Dupont, G, Moalla, W, Guinhouya, C, Ahmaidi, S, and Berthoin, S. Effects of passive versus active recovery during high-intensity intermittent exercise. Med Sci Sports Exerc 36: 302 308, 2004. 10. Foster, C, Florhaug, JA, Franklin, J, Gottschall, L, Hrovatin, LA, Parker, S, Doleshal, P, and Dodge, C. A new approach to monitoring exercise training. J Strength Cond Res 15: 109 115, 2001. 11. Gabbett, T, Jenkins, D, and Abernethy, B. Physical collisions and injury during professional rugby league skills training. J Sci Med Sport 13: 578 583, 2010. 12. Gabbett, TJ. Activity cycles of National Rugby League and National Youth Competition matches. J Strength Cond Res 26: 1517 1523, 2012. 13. Gabbett, TJ. Sprinting patterns of National Rugby League competition. J Strength Cond Res 26: 121 130, 2012. 14. Gabbett, TJ, Jenkins, DG, and Abernethy, B. Physical demands of professional rugby league training and competition using microtechnology. J Sci Med Sport 15: 80 86, 2012. 15. Gabbett, TJ and Mulvey, MJ. Time-motion analysis of small-sided training games and competition in elite women soccer players. J Strength Cond Res 22: 543 552, 2008. 16. Johnston, R and Gabbett, TJ. Repeated-sprint and effort ability in rugby league players. J Strength Cond Res 25: 2789 2795, 2011. 17. Meir, R, Arthur, D, and Forrest, M. Time motion analysis of professional rugby league: A case study. Strength Cond Coach 1: 24 29, 1993. 18. Mohr, M, Krustrup, P, Andersson, H, Kirkendal, D, and Bangsbo, J. Match activities of elite women soccer players at different performance levels. J Strength Cond Res 22: 341 349, 2008. 19. Petersen, C, Pyne, D, Portus, M, and Dawson, B. Validity and reliability of GPS units to monitor cricket-specific movement patterns. Int J Sports Physiol Perform 4: 381 393, 2009. 20. Rampinini, E, Coutts, AJ, Castagna, C, Sassi, R, and Impellizzeri, FM. Variation in top level soccer match performance. Int J Sports Med 28: 1018 1024, 2007. 21. Rampinini, E, Impellizzeri, FM, Castagna, C, Coutts, AJ, and Wisloff, U. Technical performance during soccer matches of Italian Serie A league: Effect of fatigue and competitive level. J Sci Med Sport 12: 227 233, 2009. 22. Sirotic, AC, Coutts, AJ, Knowles, H, and Catterick, C. A comparison of match demands between elite and semi-elite rugby league competition. J Sports Sci 27: 203 211, 2009. 23. Sykes, D, Twist, C, Hall, S, Nicholas, C, and Lamb, K. Semiautomated time-motion analysis of senior elite rugby league. Int J Perform Anal Sport 9: 47 59, 2009. 24. Twist, C, Waldron, M, Highton, J, Burt, D, and Daniels, M. Neuromuscular, biochemical, and perceptual post-match fatigue in professional rugby league forwards and backs. J Sports Sci 30: 359 367, 2012. 25. Waldron, M, Twist, C, Highton, J, Worsfold, P, and Daniels, M. Movement and physiological match demands of elite rugby league using portable global positioning systems. J Sports Sci 29: 1223 1230, 2011. VOLUME 27 NUMBER 6 JUNE 2013 1635