Do players and staff sleep more during the pre- or competitive season of elite rugby league?

This study establishes the sleep behaviour of players and staff during the pre- and competitive seasons of elite rugby league. For seven days during both the pre- and competitive seasons, seven rugby league players and nine full-time staff from one professional Australian rugby league club had their sleep monitored via wrist actigraphy and self-report sleep diaries. Two-way repeated measures analysis of variance determined differences between the pre- and competitive season in players and staff, with effect sizes (ES) used to interpret the practical magnitude of differences. Findings show an earlier bed time and wake time for players (?34 min, ES?=?1.5; ±0.5 and ?39 min, 2.1; ±0.5 respectively) and staff (?29 min, ES?=?0.8; ±0.3 and ?35 min, ES?=?1.7; ±0.4 respectively) during pre-season when compared to the competitive season. Despite this, no differences were seen when considering the amount of time in bed, sleep duration or sleep efficiency obtained between the pre- and competitive seasons. Our results suggest that early morning training sessions scheduled during pre-season advances wake time in elite rugby league. However, both players and staff can aim to avoid reductions in sleep duration and sleep efficiency with subsequent adjustment of night time sleep patterns. This may be particularly pertinent for staff, who wake earlier than players during both the pre- and competitive seasons.     

Acute sleep hygiene strategy improves objective sleep latency following a late-evening soccer-specific training session: A randomized controlled trial

ABSTRACT

The aim of this study was to evaluate the effects of sleep hygiene (SH) education on sleep quality in soccer players after a late-evening small-sided-game (SSG) training session. Twenty-nine non-professional players were recruited and allocated to either an experimental group (EG, n = 17) that received SH education, or a control group (CG, n = 12). SSG consisted of 3 × 4 min in a 4vs4, with 3 min of recovery and was performed at 8.00 p.m. Sleep quality was monitored via actigraphy and sleep diary entries before (PRE) and two nights after (POST1, POST2) the SSG. Sleep latency (SL) differed between the two groups at POST1 (4.9 ± 5.4 vs. 15.5 ± 16.1 for EG and CG, respectively; p = 0.017, effect size [ES] = 2.0); SL values were lower at POST1 compared to PRE for the EG (?47%; p = 0.021, ES = 0.6). Subjective sleep quality was better in the EG than the CG at POST1 (8.6 ± 1.0 vs. 7.1 ± 2.0 for EG and CG, respectively; p = 0.016, ES = 0.9) with a significant improvement over PRE-values (+11.0%, p = 0.004, ES = 0.8). Although SL and subjective sleep quality did not decrease significantly from POST1 to POST2 values at POST2 no longer differed significantly form baseline and, hence, indicate that observed effects may be short-lasting. No other objective sleep indices were influenced by late-evening training or SH practices implemented by the EG. Soccer players may benefit from acute SH strategies to reduce the time to sleep onset after late-evening training sessions.     

The organised chaos of English adolescent rugby union: Influence of weekly match frequency on the variability of match and training loads

The aims of this study were to determine the variability of weekly match and training loads in adolescent rugby union players across a competitive season, and to investigate the effect of match frequency on load distribution across different activities. Internal match and training load data (i.e. session-rating of perceived exertion (sRPE)) were collected daily from 20 players from a regional academy across a 14-week season. Data were analysed using a mixed-effects linear model, and variability was reported as a coefficient of variation (CV). Differences between 0-, 1-, 2-, and 3-match weeks were assessed using Cohen’s d effect sizes and magnitude-based inferences. Mean weekly total match and training sRPE load was 1425?±?545 arbitrary units (AU), with a between-player CV of 10?±?6% and within-player CV of 37?±?3%. Mean week-to-week change in total sRPE load was 497?±?423?AU (35%), and 40% of weekly observations were outside the suggested acute:chronic workload ratio ‘safe zone’. Total weekly sRPE loads increased substantially with match frequency (1210?±?571, 1511?±?489, and 1692?±?517?AU, for 0-, 1-, and 2-match weeks, respectively), except for 3-match weeks (1520?±?442?AU). Weekly match and training loads were highly variable for adolescent rugby players during the competitive season, and match frequency has a substantial effect on the distribution of loads. Therefore, match and training loads should be coordinated, monitored, and managed on an individual basis to protect players from negative training consequences, and to promote long-term athlete development.     

Monitoring residual 36 h post-match neuromuscular fatigue in rugby union; a role for postural control?

Abstract

The present study investigated single-leg balance and landing measures, respectively, at the beginning of a weekly micro-cycle 36?h after a match compared to 48?h rest without any match load. Twenty-seven professional rugby union players performed balance and landing tests on a 1000?Hz force plate across three in-season micro-cycles either with or without match loads in the prior 36?h. Participants were further sub-divided into higher and lower match load groups to investigate changes in balance and landing variables. Differences between rested and 36?h post-match single-leg balance sway velocity were trivial in all cases, except for the higher-load group on the dominant leg, which were possibly impaired 36?h post-match (ES?±?90% CL?=?0.68?±?0.66). Differences between rested and 36?h post-match single-leg landing measures of relative impulse on the non-dominant leg were possibly lower (0.36?±?0.34), with possible impairment observed on both legs in the higher load group 36?h post-match (0.39?±?0.33; 0.49?±?0.42). Differences in landing measures of peak force and time to stabilisation were mainly trivial (ES?<?0.20). Postural control measures at 36?h post-match are comparable to a rested state; though impairment of sway velocity on the dominant leg and landing impulse may indicate residual neuromuscular fatigue resulting from increased match exposure.     

External Activity Demands Differ Between Referees and Players During a Sub-Elite,Men’s Basketball Match

ABSTRACT

Match activity demands of basketball players have been well reported but little exists in terms of quantifying the demands encountered by referees during match-play. Potential differences between referees and players may identify different fitness capacities and subsequent need for different training regimes. Purpose: The aims of this brief report were to: 1) document the activity demands of sub-elite basketball referees during a match; and 2) compare referee and player match activity demands. Method: Three referees and six players participating in the same sub-elite, basketball match were monitored for external activity (PlayerLoad?, PL) via microsensor technology. The proportion of each quarter and entire match time spent in pre-set PL bands was also examined to develop PL profiles. Differences in activity demands between referees and players were calculated using effect size (ES) analyses (± 95% confidence intervals). Results: Referees experienced an absolute PL of 310 ± 28 arbitrary units (4.2 ± 0.4 AU.min^?1) during the match which was ~40% lower than that of the players (ES = 1.14; ?0.45, 2.48). Referees exhibited a match PL profile dominated by the lowest PL band (~91%) with the players’ PL profile shifted slightly towards higher bands. Conclusion: Sub-elite basketball referees experienced activity demands substantially lower than that of players during the same match. Limited movement patterns due to recommended court positioning may have contributed to the lower PL of referees. Differences in PL between referees and players highlight a need to develop specific training regimes to focus on key fitness capacities for each match role.     

A season long investigation into the effects of injury,match selection and training load on mental wellbeing in professional under 23 soccer players: A team case study

Abstract

This study examined the influence of injury, match selection and training load on mental wellbeing (MW) in a squad of professional soccer players. Using a longitudinal design, twenty-five male soccer players (age, 20?±?1 years, height, 1.80?±?5.79 m, body mass 76.33?±?7.52?kg) from the under 23 squad playing in the Premier League 2 division in the UK completed the Warwick–Edinburgh Mental Well-being Scale (WEMWBS) each week of the 2017/2018 season (37 weeks in total). Injury and non-selection for the match squad were the only significant predictors of MW (P?<?0.05). Injury had the biggest influence on MW that was lower when injured vs. not injured (43.6?±?5.0 vs. 49.9?±?3.5, respectively, P?=?0.001, ES?=?1.48), accounting for 40% of the variation in MW. This increased to 50% when not being selected to play games was also considered. Weekly training loads measured by GPS (total distance, sprint distance and total duration) and individual player win rate did not influence MW (P?>?0.05). These findings highlight the importance of monitoring MW in professional soccer players and suggest that injured players and those rarely selected for the match squad should be educated on the strategies available for managing their mental health and wellbeing.     

Sleep and stress hormone responses to training and competition in elite female athletes

Stress hormone and sleep differences in a competition versus training setting are yet to be evaluated in elite female team-sport athletes. The aim of the current study was to evaluate salivary cortisol and perceptual stress markers during competition and training and to determine the subsequent effects on sleep indices in elite female athletes. Ten elite female netball athletes (mean?±?SD; age: 23?±?6 years) had their sleep monitored on three occasions; following one netball competition match (MATCH), one netball match simulation session (TRAIN), and one rest day (CONTROL). Perceived stress values and salivary cortisol were collected immediately pre- (17:15 pm) and post-session (19:30 pm), and at 22:00 pm. Sleep monitoring was performed using wrist actigraphy assessing total time in bed, total sleep time (TST), efficiency (SE%), latency, sleep onset time and wake time. Cortisol levels were significantly higher (p?p?p?相似文献   

Physical demands of game-based training drills in women’s team handball

Game-based training drills are popular in team sports. This study compared two game-based training conditions and official matches in team handball. Thirty-one women players wore inertial measurement units in five training sessions and five official matches. In training, 3vs3 and 6vs6 game-based training conditions were performed with a 5-min duration. PlayerLoad? and high-intensity events (HIEs; >2.5 m · s^?1) were extracted from the raw data. Data were analysed using magnitude-based inferences and reported with effect sizes (ESs). PlayerLoad? · min^?1 from all positions combined was 11.37 ± 0.49 (mean ± 90% confidence limits) and 9.71 ± 0.3 for the 3vs3 and 6vs6 conditions, respectively. Backs (ES: 1.63), wings (ES: 1.91), and pivots (ES: 1.58) had greater PlayerLoad? in 3vs3 than 6vs6. Substantially greater HIE · min^?1 in 3vs3 occurred for all positions. There was substantially greater PlayerLoad? · min^?1 in 3vs3 and 6vs6 than match play for backs, wings, and pivots. Wings (ES: 1.95), pivots (ES: 0.70), and goalkeeper (ES: 1.13) had substantially greater HIE · min^?1 in 3vs3 than match play. This study shows greater PlayerLoad? and HIE in 3vs3 than 6vs6. Both game-based training conditions investigated in this study provide an overload in overall PlayerLoad?; however, additional exercises might be needed to overload HIE, especially for backs and pivots.     

Quantification of training load during one-, two- and three-game week schedules in professional soccer players from the English Premier League: implications for carbohydrate periodisation

Muscle glycogen is the predominant energy source for soccer match play, though its importance for soccer training (where lower loads are observed) is not well known. In an attempt to better inform carbohydrate (CHO) guidelines, we quantified training load in English Premier League soccer players (n = 12) during a one-, two- and three-game week schedule (weekly training frequency was four, four and two, respectively). In a one-game week, training load was progressively reduced (P < 0.05) in 3 days prior to match day (total distance = 5223 ± 406, 3097 ± 149 and 2912 ± 192 m for day 1, 2 and 3, respectively). Whilst daily training load and periodisation was similar in the one- and two-game weeks, total accumulative distance (inclusive of both match and training load) was higher in a two-game week (32.5 ± 4.1 km) versus one-game week (25.9 ± 2 km). In contrast, daily training total distance was lower in the three-game week (2422 ± 251 m) versus the one- and two-game weeks, though accumulative weekly distance was highest in this week (35.5 ± 2.4 km) and more time (P < 0.05) was spent in speed zones >14.4 km · h^?1 (14%, 18% and 23% in the one-, two- and three-game weeks, respectively). Considering that high CHO availability improves physical match performance but high CHO availability attenuates molecular pathways regulating training adaptation (especially considering the low daily customary loads reported here, e.g., 3–5 km per day), we suggest daily CHO intake should be periodised according to weekly training and match schedules.     

Pre-training perceived wellness impacts training output in Australian football players

The impact of perceived wellness on a range of external load parameters, rating of perceived exertion (RPE) and external load:RPE ratios, was explored during skill-based training in Australian footballers. Fifteen training sessions involving 36 participants were analysed. Each morning before any physical training, players completed a customised perceived wellness questionnaire (sleep quality, fatigue, stress, mood and muscle soreness). Microtechnology devices provided external load (average speed, high-speed running distance, player load and player load slow). Players provided RPE using the modified Borg category-ratio 10 RPE scale. Mixed-effect linear models revealed significant effects of wellness Z-score on player load and player load slow. Effects are reported with 95% confidence limits. A wellness Z-score of ?1 corresponded to a ?4.9 ± 3.1 and ?8.6 ± 3.9% reduction in player load and player load slow, respectively, compared to those without reduced wellness. Small significant effects were also seen in the average speed:RPE and player load slow:RPE models. A wellness Z-score of ?1 corresponded to a 0.43 ± 0.38 m·min^?1 and ?0.02 ± 0.01 au·min^?1 change in the average speed:RPE and player load slow:RPE ratios, respectively. Magnitude-based analysis revealed that the practical size of the effect of a pre-training perceived wellness Z-score of ?1 would have on player load slow was likely negative. The results of this study suggests that monitoring pre-training perceived wellness may provide coaches with information about the intensity of output that can be expected from individual players during a training session.     

Characteristics impacting on session rating of perceived exertion training load in Australian footballers

The relationship between external training load and session rating of perceived exertion (s-RPE) training load and the impact that playing experience, playing position and 2-km time-trial performance had on s-RPE training load were explored. From 39 Australian Football players, 6.9 ± 4.6 training sessions were analysed, resulting in 270 samples. Microtechnology devices provided external training load (distance, average speed, high-speed running distance, player load (PL) and player load_slow (PL_slow)). The external training load measures had moderate to very large associations (r, 95% CI) with s-RPE training load, average speed (0.45, 0.35–0.54), high-speed running distance (0.51, 0.42–0.59), PL_slow (0.80, 0.75–0.84), PL (0.86, 0.83–0.89) and distance (0.88, 0.85–0.90). Differences were described using effect sizes (d ±95% CL). When controlling for external training load, the 4- to 5-year players had higher s-RPE training load than the 0- to 1- (0.44 ± 0.33) and 2- to 3-year players (0.51 ± 0.30), ruckmen had moderately higher s-RPE training load than midfielders (0.82 ± 0.58), and there was a 0.2% increase in s-RPE training load per 1 s increase in time-trial (95% CI: 0.07–0.34). Experience, position and time-trial performance impacted the relationship between external training load and s-RPE training load. This suggests that a given external training load may result in different internal responses between athletes, potentially leaving individuals at risk of overtraining or failing to elicit positive adaptation. It is therefore vital that coaches and trainers give consideration to these mediators of s-RPE training load.     

Caffeine use in a Super Rugby game and its relationship to post-game sleep

Objective: To examine the relationship between regular game-related caffeine consumption on sleep after an evening Super Rugby game. Methods: Twenty elite rugby union players wore a wrist-activity monitor to measure sleep for three days before, three days after and on the night of an evening Super Rugby game (19:00–21:00). Players ingested caffeine as they would normally (i.e. before and sometimes during a game) and saliva samples were collected before (17:00) and after (21:30) the game for caffeine concentration. Results: Compared to the nights leading up to the game, on the night of the game, players went to bed 3?h later (23:08?±?66?min vs 02:11?±?114?min; p?p?p?p?p?p?=?.06) on game night. Conclusion: Caffeine consumption before a Super Rugby game markedly increases post-game saliva caffeine levels. This may contribute to the observed 3.5?h delay in time at sleep onset and the 1.5?h reduction in sleep duration on the night of the game. This study highlights the need for a strategic approach to the use of caffeine within a Super Rugby team considering the potential effect on post-game sleep.     

Futsal task constraints promote transfer of passing skill to soccer task constraints

This study investigated how learning a passing skill with futsal or soccer task constraints influenced transfer to a new task. Futsal (n?=?24, 13.6?±?1.2 years old, 7.0?±?1.6 years of experience) and soccer (n?=?24, 13.6?±?1.2 years old, 6.8?±?1.2 years of experience) players performed two 5v5?+?goalkeeper modified games – a futsal-like task (small playing area with the futsal ball) and soccer-like task (large playing area with the soccer ball). Participants’ passing accuracy and their orientation of attention were assessed during the two tasks. The futsal group improved their passing accuracy (ES?=?0.75?±?0.61) from the futsal-like to the soccer-like task, and they were more accurate than soccer players (ES?=?2.98?±?2.96). Conversely, the soccer group’s passing accuracy remained stable across the two tasks (ES?=?0.10?±?0.52) and it was similar to the futsal group in the futsal-like task (ES?=?0.58?±?1.93). This indicates a higher magnitude of transfer (and adaptability) from performing passes in a small playing area with short time to act – futsal task constraints – to a larger playing area with longer time – soccer task constraints – than vice-versa. Furthermore, the futsal group showed a higher adaptation of attention orientation to the affordances that emerged with the soccer task constraints, which is suggested to be one of the main mechanisms promoting skill transfer. These results encourage soccer practitioners to introduce futsal task constraints to fast-track players’ ability to functionally adapt perception–action coupling.     

Effects of tapering on physical match activities in professional soccer players

ABSTRACT

This study aimed to examine: (i) the effect of decreasing training load (TL) during taper weeks on physical match activities in professional soccer players, and (ii) to disclose the relationship between weekly TL and physical match activities. Rating of perceived exertion was collected after each training session and match to quantify the TL in 19 professional players over 17 standard and 7 taper weeks during the season. Physical match activities were quantified by a computerised match analysis system and compared between standard training and taper weeks. Compared to standard weeks, the duration and frequency of training sessions during the taper weeks decreased (?21.7% and ?18.8%, respectively; P < 0.01) with no change in intensity (?4.8%; P = 0.09). Consequently, the weekly TL decreased during the taper weeks (?25.5%; P < 0.01). Increases in distance covered by intense running (+15.1%; P < 0.05), high-intensity running (HIR) (+15.7%; P < 0.01), number of sprints (+17.8%; P < 0.05) and number of high-speed runs (+15.7%; P < 0.05) were observed during the seven matches played after the taper weeks. High relationships were observed between TL and HIR distance covered, number of HIR and number of sprints (r = ?0.53; r = ?0.55; r = ?0.65, respectively; P < 0.01). Decreasing TL during taper weeks by reducing training duration and frequency but maintaining intensity was associated with an increase in physical activities during matches. However, it needs to be determined whether tapering or other match factors led to the changes in match activity.     

Effect of two different intensity distribution training programmes on aerobic and body composition variables in ultra-endurance runners

The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n?=?11; age: 40.6?±?9.7 years; height: 175.4?±?7?cm; weight: 73.5?±?10.8?kg; fat mass 18.4?±?6.0%; VO₂max: 55.8?±?4.9?ml/kg/min) or THR group (n?=?9; age: 36.8?±?9.2 years; height: 178.5?±?4.2?cm; weight: 75.5?±?10.4?kg; fat mass 14.9?±?5.3%; VO₂max: 57.1?±?5.2?ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL?=?79.8?±?2.1% in Zone 1; 3.9?±?1.9% in Zone 2; 16.4?±?1.5% in Zone 3; THR?=?67.2?±?4.6% in Zone 1; 33.8?±?4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ–11.2%; p?=?.017; ES?=?0.32; THR= Δ–18.8%; p?p?=?0.003; ES?=?0.71) and 12?km/h (Δ–4.5%; p?=?.026; ES?=?0.73) and running time to exhaustion (Δ2.4%; p?=?.011; ES?=?0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners.     

Evidence of sub-optimal sleep in adolescent Middle Eastern academy soccer players which is exacerbated by sleep intermission proximal to dawn†

The purpose was to assess sleep patterns, quantity and quality in adolescent (16.2?±?1.2 yr) Middle Eastern academy soccer players (n?=?20) and the influence of an intermission upon these characteristics. On a 17-day training camp (located one time zone west of home) including three discrete matches, sleep was assessed pre- (PRE) and post-match (POST) via wrist actigraphy. Retrospective actigraphy analysis identified sleep characteristics, including if players experienced a sleep intermission (YES) or not (NO) proximal to dawn, and bedtime (hh:mm), get-up time (hh:mm), time in bed (h), sleep duration (h) and sleep efficiency (%). Within YES two bouts were identified (BOUT1 and BOUT2). No differences were seen between PRE and POST, nor between BOUT1 and BOUT2 (p?>?.05). Overall players did not meet National Sleep Foundation (NSF) guidelines (7:04?±?1:16?h vs. recommended 8–10?h for 14–17 yr). Sleep duration was significantly reduced (～ ?13% or ?1:06) in YES compared to NO (6:33?±?1:05 vs. 7:29?±?1:17, p?<?.01). Despite players in YES waking earlier due to an intermission, they did not compensate for this with a later wake time, rising significantly earlier compared to NO (09:40?±?00:38 vs. 10:13?±?00:40, p?<?.05). These players on average do not obtain sufficient sleep durations relative to NSF guidelines, with decrements increased by an intermission proximal to dawn. High inter- and intra-individual variance in the players sleep characteristics indicates the need for individualized sleep education strategies and interventions to promote appropriate sleep.     

大学生足球比赛负荷特征研究——基于数据级数推断与广义混合线性模型的分析

运用“简极-茵战K1”智能足球运动表现分析系统采集12名大学生运动员在8场正式足球比赛中的跑动和心率相关指标,量化运动员的外部和内部比赛负荷。结果显示：（1）在外部负荷方面,大学生足球运动员在正式的足球比赛中场均跑动距离（8 464±822） m,其中,慢速跑跑动距离约占39.8%,低速跑跑动距离约占30.2%,高强度跑动距离约占5.1%,场均高强度跑动次数（30±14）次;在内部负荷方面,运动员在比赛中的平均心率为（160±11） 次/分钟,52%的比赛时间处于80%最大心率以上区间,仅有14.5%的比赛时间内处于70%最大心率以下区间。（2）后卫球员的跑动总距离大程度地低于中场（ES=1.2,可能性>95%）和前锋（ES=1.4,可能性>95%）,高强度跑平均间歇时间则中等程度地高于中场（ES=0.6,可能性>75%）和前锋（ES=0.9,可能性>75%）,后卫球员在比赛处于中高强度心率区间的时间比例中等程度地低于中场（ES=1.0,可能性>95%）和前锋（ES=1.1,可能性>75%）。前锋球员在比赛中的最大跑动速度（ES=0.7,可能性>75%）、步行距离（ES=0.8,可能性>75%）、慢速跑跑动距离（ES=0.6,可能性>75%）和中等强度心率区间占比（ES=0.7,可能性>75%）皆中等程度地高于中场球员,而低速跑跑动距离（ES=0.8,可能性>75%）、平均心率（ES=0.6,可能性>75%）和高强度心率区间占比（ES=0.6,可能性>95%）则都中等程度的低于中场球员。     

Caffeine ingestion acutely enhances muscular strength and power but not muscular endurance in resistance-trained men

The goal of this randomized, double-blind, cross-over study was to assess the acute effects of caffeine ingestion on muscular strength and power, muscular endurance, rate of perceived exertion (RPE), and pain perception (PP) in resistance-trained men. Seventeen volunteers (mean?±?SD: age?=?26?±?6 years, stature?=?182?±?9?cm, body mass?=?84?±?9?kg, resistance training experience?=?7?±?3 years) consumed placebo or 6?mg?kg^?1 of anhydrous caffeine 1?h before testing. Muscular power was assessed with seated medicine ball throw and vertical jump exercises, muscular strength with one-repetition maximum (1RM) barbell back squat and bench press exercises, and muscular endurance with repetitions of back squat and bench press exercises (load corresponding to 60% of 1RM) to momentary muscular failure. RPE and PP were assessed immediately after the completion of the back squat and bench press exercises. Compared to placebo, caffeine intake enhanced 1RM back squat performance (+2.8%; effect size [ES]?=?0.19; p?=?.016), which was accompanied by a reduced RPE (+7%; ES?=?0.53; p?=?.037), and seated medicine ball throw performance (+4.3%, ES?=?0.32; p?=?.009). Improvements in 1RM bench press were not noted although there were significant (p?=?.029) decreases in PP related to this exercise when participants ingested caffeine. The results point to an acute benefit of caffeine intake in enhancing lower-body strength, likely due to a decrease in RPE; upper-, but not lower-body power; and no effects on muscular endurance, in resistance-trained men. Individuals competing in events in which strength and power are important performance-related factors may consider taking 6?mg?kg^?1 of caffeine pre-training/competition for performance enhancement.     

Intensities of exercise during match-play in FA Premier League referees and players

Abstract

The aim of the present study was to examine the relationship between intensities of exercise during match-play of elite-standard soccer referees with those of the players from the same match. Match analysis data were collected (Prozone® Leeds, UK) for 18 elite-standard soccer referees (age 26–49 years) on FA Premier League matches during the 2008/09 English FA Premier League season (236 observations). Running categories for referees and players were as follows: total distance covered (m); high-speed running distance (speed >19.8 km · h^?1); and sprinting distance (speed >25.2 km · h^?1). Analysis of the distance–time regression coefficients revealed no differences between the referees' and players' within-match rates of change for total distance covered (?0.594 ± 0.394 vs. ?0.713 ± 0.269 m · min^?1; P = 0.104), high-speed running (?0.039 ± 0.077 vs. ?0.059 ± 0.030 m · min^?1; P = 0.199), and sprinting (?0.003 ± 0.039 vs. ?0.021 ± 0.017 m · min^?1; P = 0.114). In addition, there were no differences between across-season rates of change for total distance (–26.756 ± 40.434 vs. ?20.031 ± 25.502 m per match day; P = 0.439) and sprinting (–9.662 ± 7.564 vs. ?8.589 ± 4.351 m per match day; P = 0.542). These results show that elite-standard soccer referees' intensities of exercise during match-play are interrelated with those of the players and thus demonstrate that referees are able to keep pace with the players during FA Premier League matches.