match performance variables were collected alongside player well-being variables and individual contextual factors relating to the match. Data Collection Activity profiles during matches were measured using 15-Hz global positioning system devices (SPI HPU; GPSports, Canberra, Australia). These have
Mitchell J. Henderson, Job Fransen, Jed J. McGrath, Simon K. Harries, Nick Poulos and Aaron J. Coutts
Courtney Sullivan, Thomas Kempton, Patrick Ward and Aaron J. Coutts
, comparatively less research has been performed in team sports. This is predominately due to the difficulty in identifying an individual measure of performance for team-sport athletes and the added complexity of playing positions. 4 Despite these limitations, it is routine to measure individual match performance
Paul S. Bradley and Jack D. Ade
scientifically. 9 Using the traditional approach, physical match performances have been quantified across competitions such as the English Premier League, 10 , 11 Italian Serie A, 6 , 12 Spanish La Liga, 13 French Ligue 1, 14 and German Bundesliga 15 in addition to the European Champions League 16 , 17 and
Matthew Weston, Alan M. Batterham, Carlo Castagna, Matthew D. Portas, Christopher Barnes, Jamie Harley and Ric J. Lovell
Soccer referees’ physical match performances at the start of the second half (46–60 min) were evaluated in relation to both the corresponding phase of the first half (0–15 min) and players’ performances during the same match periods.
Match analysis data were collected (Prozone, UK) from 12 soccer referees on 152 English Premier League matches during the 2008/09 soccer season. Physical match performance categories for referees and players were total distance, high-speed running distance (speed >5.5 m/s), and sprinting distance (>7.0 m/s). The referees’ heart rate was recorded from the start of their warm-up to the end of the match. The referees’ average distances (in meters) from the ball and fouls were also calculated.
No substantial differences were observed in duration (16:42 ± 2:35 vs 16:27 ± 1:00 min) or intensity (107 ± 11 vs 106 ± 14 beats/min) of the referees’ preparation periods immediately before each half. Physical match performance was reduced during the initial phase of the second half when compared with the first half in both referees (effect sizes—standardized mean differences—0.19 to 0.73) and players (effect sizes 0.20 to 1.01). The degree of the decreased performance was consistent between referees and players for total distance (4.7 m), high-speed running (1.5 m), and sprinting (1.1 m). The referees were closer to the ball (effect size 0.52) during the opening phase the second half.
Given the similarity in the referees’ preparation periods, it may be that the reduced physical match performances observed in soccer referees during the opening stages of the second half are a consequence of a slower tempo of play.
Paul S. Bradley, Carlos Lago-Peñas and Ezequiel Rey
To evaluate match performances of substitute players using different research designs.
English Premier League matches were analyzed using a multiple-camera system. Two research designs were adopted: an independent-measures analysis comparing the match-performance characteristics of players completing the entire match (n = 810) vs substitutes (n = 286) and the players they replaced (n = 286) and a repeated-measures analysis comparing the same players completing full matches vs those in which they were introduced as a substitute (n = 94).
Most substitutions (P < .05) occurred at halftime and between the 60- to 85-min vs all first-half periods and the remaining second-half periods (effect size [ES]: 0.85–1.21). These substitutions become more (P < .01) offensive (eg, more attacking positions were introduced) in relation to the positions introduced as the half progressed (ES: 0.93–1.37). Independent-measures analysis indicated that high-intensity running was greater (P < .01) in substitutes compared with players who either completed the entire match or were replaced (ES: 0.28–0.67), but no differences were evident for pass-completion rates (ES: 0.01–0.02). Repeated-measures analysis highlighted that players covered more (P < .01) high-intensity running when they were introduced as substitutes compared with the equivalent period of the second- but not the first-half period (ES: 0.21–0.47). Both research designs indicated that attackers covered more (P < .05) high-intensity running than peers or their own performances when completing the entire match (ES: 0.45– 0.71).
Substitutes cover greater high-intensity-running distance; this was particularly evident in attackers, but pass-completion rates did not differ for any position. This information could be beneficial to coaches regarding optimizing the match running performances of their players, but much more work needs to be undertaken to investigate the overall impact of substitutes (physical, technical indicators, and contribution to key moments of matches).
Frankie Tan, Ted Polglaze, Gregory Cox, Brian Dawson, Iñigo Mujika and Sally Clark
This study investigated the effects of sodium bicarbonate (NaHCO3) ingestion on simulated water polo match performance. Twelve elite players from the Australian National Women’s Water Polo Squad (age 23.7 ± 3.0 yr, height 1.73 ± 0.05 m, body mass 75.7 ± 8.0 kg) participated in the study. In a randomized cross-over double-blind design, players ingested 0.3 g/kg of NaHCO3 or placebo 90 min before performing a 59-min match-simulation test (MST) that included 56 × 10-m maximal-sprint swims as the performance measure. Capillary blood samples were obtained preingestion, pre- and post-warm-up, and after each quarter of the MST. Preexercise ingestion of NaHCO3 was effective in enhancing extracellular pH from baseline levels of 7.41; ±0.01 (M; ±90% confidence limits) to 7.49; ±0.01 and bicarbonate levels from 24.4; ±0.3 to 28.5; ±0.5 mmol/L. The percentage difference in mean sprint times between trials showed no substantial effects of NaHCO3 (0.4; ±1.0, effect size = 0.09; ±0.23; p = .51). These findings are contrary to those of previous NaHCO3 studies on simulated team-sport performance, but this investigation is unique in that it examined highly trained athletes performing sport-specific tasks. In conclusion, water polo players should not expect substantial enhancement in intermittent-sprint performance from NaHCO3 supplementation.
Samuel Ryan, Aaron J. Coutts, Joel Hocking, Patrick A. Dillon, Anthony Whitty and Thomas Kempton
data are interpreted in the context of changes in physical capacity and match performance, coaches and scientists can gain a better understanding of player preparation, enhancing strategies to achieve optimal competition performance. 1 Previous studies in Australian football and rugby league have
Hugh H.K. Fullagar, Rob Duffield, Sabrina Skorski, David White, Jonathan Bloomfield, Sarah Kölling and Tim Meyer
The current study examined the sleep, travel, and recovery responses of elite footballers during and after long-haul international air travel, with a further description of these responses over the ensuing competitive tour (including 2 matches).
In an observational design, 15 elite male football players undertook 18 h of predominantly westward international air travel from the United Kingdom to South America (–4-h time-zone shift) for a 10-d tour. Objective sleep parameters, external and internal training loads, subjective player match performance, technical match data, and perceptual jet-lag and recovery measures were collected.
Significant differences were evident between outbound travel and recovery night 1 (night of arrival; P < .001) for sleep duration. Sleep efficiency was also significantly reduced during outbound travel compared with recovery nights 1 (P = .001) and 2 (P = .004). Furthermore, both match nights (5 and 10), showed significantly less sleep than nonmatch nights 2 to 4 and 7 to 9 (all P < .001). No significant differences were evident between baseline and any time point for all perceptual measures of jet-lag and recovery (P > .05), although large effects were evident for jet-lag on d 2 (2 d after arrival).
Sleep duration is truncated during long-haul international travel with a 4-h time-zone delay and after night matches in elite footballers. However, this lost sleep appeared to have a limited effect on perceptual recovery, which may be explained by a westbound flight and a relatively small change in time zones, in addition to the significant increase in sleep duration on the night of arrival after the long-haul flight.
Mark Waldron and Aron Murphy
This study aimed to identify characteristics of match performance and physical ability that discriminate between elite and subelite under-14 soccer players. Players were assessed for closed performance and movement, physiological responses, and technical actions during matches. Elite players covered more total m·min−1 (115.7 ± 6.6 cf. 105.4 ± 7.7 m·min−1) and high-intensity m·min−1 (elite = 14.5 ± 2.3 cf. 11.5 ± 3.7 m·min−1) compared with subelite players. Elite players also attempted more successful (0.41 ± 0.11 cf. 0.18 ± 0.02) and unsuccessful ball retentions·min−1 (0.14 ± 0.04 cf. 0.06 ± 0.02) compared with subelite players. Elite players were faster over 10 m (1.9 ± 0.1 cf. 2.3 ± 0.2 s) and faster dribblers (16.4 ± 1.4 cf. 18.2 ± 1.1 s) compared with subelite players. Speed (10 m) and successful ball retention·min−1 contributed to a predictive model, explaining 96.8% of the between-group variance. The analysis of match performance provides a more thorough understanding of the factors underlying talent among youth soccer players.
Stuart R. Graham, Stuart Cormack, Gaynor Parfitt and Roger Eston
match were excluded from the analyses for each participant. An individual player’s MEI/min was excluded from analysis if he was injured pregame (but was selected to play) or injured in game (but continued to play). Furthermore, match performance data were removed from analyses if the game was played