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William P. McCormack, Jay R. Hoffman, Gabriel J. Pruna, Tyler C. Scanlon, Jonathan D. Bohner, Jeremy R. Townsend, Adam R. Jajtner, Jeffrey R. Stout, Maren S. Fragala and David H. Fukuda

Purpose:

During the competitive soccer season, women’s intercollegiate matches are typically played on Friday evenings and Sunday afternoons. The efficacy of a 42-h recovery period is not well understood. This investigation was conducted to determine performance differences between Friday and Sunday matches during a competitive season.

Methods:

Ten NCAA Division I female soccer players (20.5 ± 1.0 y, 166.6 ± 5.1 cm, 61.1 ± 5.8 kg) were monitored with 10-Hz GPS devices across 8 weekends with matches played on Friday evenings and Sunday afternoons. The players were outside backs, midfielders, and forwards. All players had to participate in a minimum of 45 min/match to be included in the study. Average minutes played, total distance covered, total distance of high-intensity running (HIR) (defined as running at a velocity equal to or exceeding 3.61 m/s for longer than 1 s), the number of HIR efforts, and the number of sprints were calculated for each match. Data for Friday vs Sunday matches were averaged and then compared using dependent t tests.

Results:

No differences were seen in minutes played, distance rate, or number of sprints between Friday and Sunday matches. A significant (P = .017) decrease in rate of HIR between Friday (25.37 ± 7.22 m/min) and Sunday matches (22.90 ± 5.70 m/min) was seen. In addition, there was a trend toward a difference (P = .073) in the number of efforts of HIR between Friday (138.41 ± 36.43) and Sunday (126.92 ± 31.31).

Conclusions:

NCAA Division I female soccer players cover less distance of HIR in games played less than 48 h after another game. This could be due to various factors such as dehydration, glycogen depletion, or muscle damage.

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Juan Del Coso, Javier Portillo, Juan José Salinero, Beatriz Lara, Javier Abian-Vicen and Francisco Areces

The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink to improve physical performance of elite field hockey players during a game. On 2 days separated by a week, 13 elite field hockey players (age and body mass = 23.2 ± 3.9 years and 76.1 ± 6.1 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 min for caffeine absorption, participants played a simulated field hockey game (2 × 25 min). Individual running pace and instantaneous speed during the game were assessed using GPS devices. The total number of accelerations and decelerations was determined by accelerometry. Compared with the placebo drink, the caffeinated energy drink did not modify the total distance covered during the game (6,035 ± 451 m and 6,055 ± 499 m, respectively; p = .87), average heart rate (155 ± 13 beats per min and 158 ± 18 beats per min, respectively; p = .46), or the number of accelerations and decelerations (697 ± 285 and 618 ± 221, respectively; p = .15). However, the caffeinated energy drink reduced the distance covered at moderate-intensity running (793 ± 135 and 712 ± 116, respectively; p = .03) and increased the distance covered at high-intensity running (303 ± 67 m and 358 ± 117 m; p = .05) and sprinting (85 ± 41 m and 117 ± 55 m, respectively; p = .02). Elite field hockey players can benefit from ingesting caffeinated energy drinks because they increase the running distance covered at high-intensity running and sprinting. Increased running distance at high speed might represent a meaningful advantage for field hockey performance.

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Courtney Sullivan, Johann C. Bilsborough, Michael Cianciosi, Joel Hocking, Justin T. Cordy and Aaron J. Coutts

Objectives:

To determine the physical activity measures and skill-performance characteristics that contribute to coaches’ perception of performance and player performance rank in professional Australian Football (AF).

Design:

Prospective, longitudinal.

Methods:

Physical activity profiles were assessed via microtechnology (GPS and accelerometer) from 40 professional AF players from the same team during 15 Australian Football League games. Skill-performance measure and player-rank scores (Champion Data Rank) were provided by a commercial statistical provider. The physical-performance variables, skill involvements, and individual player performance scores were expressed relative to playing time for each quarter. A stepwise multiple regression was used to examine the contribution of physical activity and skill involvements to coaches’ perception of performance and player rank in AF.

Results:

Stepwise multiple-regression analysis revealed that 42.2% of the variance in coaches’ perception of a player’s performance could be explained by the skill-performance characteristics (player rank/min, effective kicks/min, pressure points/min, handballs/min, and running bounces/min), with a small contribution from physical activity measures (accelerations/min) (adjusted R 2 = .422, F 6,282 = 36.054, P < .001). Multiple regression also revealed that 66.4% of the adjusted variance in player rank could be explained by total disposals/min, effective kicks/min, pressure points/min, kick clangers/min, marks/min, speed (m/min), and peak speed (adjusted R 2 = .664, F 7,281 = 82.289, P < .001). Increased physical activity throughout a match (speed [m/min] β – 0.097 and peak speed β – 0.116) negatively affects player rank in AF.

Conclusions:

Skill performance rather than increased physical activity is more important to coaches’ perception of performance and player rank in professional AF.

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Robert J. Aughey

Background:

Australian football (AF) is a highly intermittent sport, requiring athletes to accelerate hundreds of times with repeated bouts of high-intensity running (HIR). Players aim to be in peak physical condition for finals, with anecdotal evidence of increased speed and pressure of these games.

Purpose:

However, no data exists on the running demands of finals games, and therefore the aim of this study was to compare the running demands of finals to regular season games with matched players and opponents.

Methods:

Player movement was recorded by GPS at 5 Hz and expressed per period of the match (rotation), for total distance, high-intensity running (HIR, 4.17-10.00 m·s-1) and maximal accelerations (2.78-10.00 m·s–2). All data was compared for regular season and finals games and the magnitude of effects was analyzed with the effect size (ES) statistic and expressed with confidence intervals.

Results:

Each of the total distance (11%; ES: 0.78 ± 0.30), high-intensity running distance (9%; ES: 0.29 ± 0.25) and number of maximal accelerations (97%; ES: 1.30 ± 0.20) increased in finals games. The largest percentage increases in maximal accelerations occurred from a commencement velocity of between 3–4 (47%; ES: 0.56 ± 0.21) and 4–5 m·s-1 (51%; ES: 0.72 ± 0.26), and with <19 s between accelerations (53%; ES: 0.63 ± 0.27).

Conclusion:

Elite AF players nearly double the number of maximal accelerations in finals compared with regular season games. This large increase is superimposed on requirements to cover a greater total distance and spend more time at high velocity during finals games. Players can be effectively conditioned to cope with these increased demands, even during a long competitive season.

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Mitchell Mooney, Stuart Cormack, Brendan O’Brien and Aaron J Coutts

Purpose:

The purpose of this study was to determine if Yo-Yo Intermittent Recovery level 2 (Yo-Yo IR2) and the number of interchange rotations affected the match activity profile of elite Australian footballers.

Method:

Fifteen elite Australian footballers completed the Yo-Yo IR2 before the beginning of the season and played across 22 matches in which match activity profiles were measured via microtechnology devices containing a global positioning system (GPS) and accelerometer. An interchange rotation was counted when a player left the field and was replaced with another player. Yo-Yo IR2 results were further split into high and low groups.

Results:

Players match speed decreased from 1st to 4th quarter, while average-speed (m/min: P = .05) and low-speed activity (LSA, <15 km/h) per minute (LSA m/min; P = .06) significantly decreased in the 2nd half. Yo-Yo IR2 influenced the amount of m/min, high-speed running (HSR, >15 km/h) per minute (HSR m/min) and accelerometer load/min throughout the entire match. The number of interchanges significantly influenced the HSR m/min and m/min throughout the match except in the 2nd quarter. Furthermore, the low Yo-Yo IR2 group had significantly less LSA m/min in the 4th quarter than the high Yo-Yo IR2 group (92.2 vs 96.7 m/min, P = .06).

Conclusions:

Both the Yo-Yo IR2 and number of interchanges contribute to m/min and HSR m/min produced by elite Australian footballers, affecting their match activity. However, while it appears that improved Yo-Yo IR2 performance prevents reductions in LSA m/min during a match, higher-speed activities (HSR m/min) and overall physical activity (m/min and load/min) are still reduced in the 4th quarter compared with the 1st quarter.

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Luis Suarez-Arrones, Javier Núñez, Diego Munguía-Izquierdo, Javier Portillo and Alberto Mendez-Villanueva

Purpose:

To examine the effects of several matches per day on running performance and cardiovascular stress in referees during a national Rugby Sevens championship.

Methods:

Seven referees, who refereed 3 matches/day, were monitored by GPS during 21 matches.

Results:

Referees’ movement patterns were relatively stable from the 1st to the 2nd match, although a substantial decrease was observed in the 2nd match for maximal and average sprint distance. A substantial decrease in the number of sprints, maximal speed, walking, distance covered at medium intensity, total and >14 km/h distance covered per minute was observed in the 3rd match in comparison with the 2nd. Compared with the 1st match, in the 3rd game referees showed a substantial decrease in maximal and average sprint distance, total walking at medium intensity, distance covered >14 km/h, and high-intensity running distance. Referees exhibited a substantial decrease in average heart rate (HR), percentage of time at >70%HRmax, and percentage of time at >90%HRmax in the 2nd match compared with the 1st. Referees’ HR responses were relatively stable from the 2nd to the 3rd match except for the HR zones of 71–80%HRmax and 81–90%HRmax and performance-efficiency index (Effindex). Substantial differences were observed in the 3rd match compared with the 1st in average HR, 81–90%HRmax, >90%HRmax, and Effindex.

Conclusion:

This study provides evidence of reduced overall running performance and pronounced reduction in high-intensity running performance during the last match in Rugby Sevens referees refereeing 3 matches in the same day.

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Avish P. Sharma, Philo U. Saunders, Laura A. Garvican-Lewis, Brad Clark, Jamie Stanley, Eileen Y. Robertson and Kevin G. Thompson

Purpose:

To determine the effect of training at 2100-m natural altitude on running speed (RS) during training sessions over a range of intensities relevant to middle-distance running performance.

Methods:

In an observational study, 19 elite middle-distance runners (mean ± SD age 25 ± 5 y, VO2max, 71 ± 5 mL · kg–1 · min–1) completed either 4–6 wk of sea-level training (CON, n = 7) or a 4- to 5-wk natural altitude-training camp living at 2100 m and training at 1400–2700 m (ALT, n = 12) after a period of sea-level training. Each training session was recorded on a GPS watch, and athletes also provided a score for session rating of perceived exertion (sRPE). Training sessions were grouped according to duration and intensity. RS (km/h) and sRPE from matched training sessions completed at sea level and 2100 m were compared within ALT, with sessions completed at sea level in CON describing normal variation.

Results:

In ALT, RS was reduced at altitude compared with sea level, with the greatest decrements observed during threshold- and VO2max-intensity sessions (5.8% and 3.6%, respectively). Velocity of low-intensity and race-pace sessions completed at a lower altitude (1400 m) and/or with additional recovery was maintained in ALT, though at a significantly greater sRPE (P = .04 and .05, respectively). There was no change in velocity or sRPE at any intensity in CON.

Conclusion:

RS in elite middle-distance athletes is adversely affected at 2100-m natural altitude, with levels of impairment dependent on the intensity of training. Maintenance of RS at certain intensities while training at altitude can result in a higher perceived exertion.

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Richard Akenhead and George P. Nassis

Training load (TL) is monitored with the aim of making evidence-based decisions on appropriate loading schemes to reduce injuries and enhance team performance. However, little is known in detail about the variables of load and methods of analysis used in high-level football. Therefore, the aim of this study was to provide information on the practices and practitioners’ perceptions of monitoring in professional clubs. Eighty-two high-level football clubs from Europe, the United States, and Australia were invited to answer questions relating to how TL is quantified, how players’ responses are monitored, and their perceptions of the effectiveness of monitoring. Forty-one responses were received. All teams used GPS and heart-rate monitors during all training sessions, and 28 used rating of perceived exertion. The top-5-ranking TL variables were acceleration (various thresholds), total distance, distance covered above 5.5 m/s, estimated metabolic power, and heart-rate exertion. Players’ responses to training are monitored using questionnaires (68% of clubs) and submaximal exercise protocols (41%). Differences in expected vs actual effectiveness of monitoring were 23% and 20% for injury prevention and performance enhancement, respectively (P < .001 d = 1.0−1.4). Of the perceived barriers to effectiveness, limited human resources scored highest, followed by coach buy-in. The discrepancy between expected and actual effectiveness appears to be due to suboptimal integration with coaches, insufficient human resources, and concerns over the reliability of assessment tools. Future approaches should critically evaluate the usefulness of current monitoring tools and explore methods of reducing the identified barriers to effectiveness.

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Carlo Castagna, Lorenzo Francini, Susana C.A. Póvoas and Stefano D’Ottavio

Purpose:

To examine the acute effects of generic drills (running drills [RDs]) and specific (small-sided-games [SSGs]) long-sprint-ability (LSA) drills on internal and external load of male soccer players.

Methods:

Fourteen academy-level soccer players (mean ± SD age 17.6 ± 0.61 y, height 1.81 ± 0.63 m, body mass 69.53 ± 4.65 kg) performed four 30-s LSA bouts for maintenance (work:rest 1:2) and production (1:5) with RDs and SSGs. Players’ external load was tracked with GPS technology (20-Hz), and heart rate (HR), blood lactate concentration (BLc), and rating of perceived exertion (RPE) were used to characterize players’ internal load. Individual peak BLc was assessed with a 30-s all-out test on a nonmotorized treadmill (NMT).

Results:

Compared with SSGs, the RDs had a greater effect on external load and BLc (large and small, respectively). During SSGs players covered more distance with high-intensity decelerations (moderate to small). Muscular RPE was higher (small to large) in RDs than in SSGs. The production mode exerted a moderate effect on BLc while the maintenance condition elicited higher cardiovascular effects (small to large).

Conclusion:

The results of this study showed the superiority of generic over specific drills in inducing LSA-related physiological responses. In this regard production RDs showed the higher postexercise BLc. Individual peak blood lactate responses were found after the NMT 30-s all-out test, suggesting this drill as a valid option to RDs. The practical physiological diversity among the generic and specific LSA drills here considered enable fitness trainers to modulate prescription of RD and SSG drills for LSA according to training schedule.

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Eduardo A. Abade, Bruno V. Gonçalves, Nuno M. Leite and Jaime E. Sampaio

Purpose:

To provide the time–motion and physiological profile of regular training sessions (TS) performed during the competitive season by under-15 (U15), under-17 (U17), and under-19 (U19) elite-level Portuguese soccer players.

Methods:

One hundred fifty-one elite players of U15 (age 14.0 ± 0.2 y, n = 56), U17 (age 15.8 ± 0.4 y, n = 66), and U19 (age 17.8 ± 0.6 y, n = 29) participated in the study during a 9-wk period. Time–motion and body-impact data were collected using GPS technology (15 Hz) across 38 randomly selected TS that resulted in a total of 612 samples. In addition, heart rate (HR) was continuously monitored (1 Hz) in the selected TS.

Results:

The total distances covered (m) were higher in U17 (4648.3 ± 831.9), followed by U19 (4212.5 ± 935.4) and U15 (3964.5 ± 725.4) players (F = 45.84, P < .001). Total body impacts and relative impacts were lower in U15 (total: 490.8 ± 309.5, F = 7.3, P < .01), but no differences were identified between U17 (total: 584.0 ± 363.5) and U19 (total: 613.1 ± 329.4). U19 players had less high- and very-high-intensity activity (above 16 km/h; F = 11.8, P < .001) and moderate-intensity activity (10.0–15.9 km/h; F = 15.07, P < .001). HR values showed significant effects of zone (F = 575.7, P < .001) and interaction with age group (F = 9.7, P < .001), with pairwise differences between all zones (zone 1, <75%; zone 2, 75–84.9%; zone 3, 85–89.9%; zone 4, ≥90%). All players spent most of their time below 75% HRmax (U15, ~50%; U17, ~42%; U19, ~50%).

Conclusion:

Results showed high variability between TS, refraining from identifying meaningful trends when measuring performance, although different demands were identified according to age group. The U15 TS were less physiologically demanding, probably because of increased focus on small-sided games to develop basic tactical principles and technical skills. The focus on game-like situations imposed higher external and internal workloads on U17 and U19 players.