Recreational football practice attenuates postprandial lipaemia in normal and overweight individuals.

INTRODUCTION: The aim of the present study was to examine the effects of playing football on postprandial lipaemia in normal and overweight individuals. METHODS: Fifteen (7 normal weight, age = 32.3 ± 6.0 years, BMI = 22.8 ± 3.4 kg/m2 and 8 overweight, age = 33.3 ± 5.5 years, BMI = 29.2 ± 3.2 kg/m2, mean ± SD) recreational football players were recruited. On the evening of day 1, participants played a 60-min 9-a-side football match (FOOT) or rested (control; CON) in a randomised counterbalanced cross-over design. Activity profile, heart rate and rate of perceived exertion were recorded. The next morning (> 10 h after the match), blood samples were collected before (0), 0.75, 2, 4, and 6 h after a high-fat meal. RESULTS: Total area under the curve for triglycerides were 22% and 28% lower for the normal weight (p < 0.01; 95% CI - 2.45 to - 0.68; ES = 0.87) and overweight (p < 0.01; 95% CI - 8.14 to - 0.88; ES = 0.68) groups in the FOOT compared to the CON. The postprandial incremental area under the curve for triglycerides was 31% lower in the normal weight group (ES = 0.79) for the FOOT compared to CON trial and a discernible trend was shown for the overweight group (22%; ES = 0.51). Two-hour Insulin Sensitivity Index was lower (ES = - 0.95) for FOOT compared to CON trial in the overweight group only. CONCLUSION: Playing a 60-min football match can attenuate the triglyceride response to a high-fat meal in normal and overweight individuals.

The relationship between lower-limb strength and match-related muscle damage in elite level professional European soccer players.

In professional soccer, the benefits of lower limb strength training have been advocated. However, from an aspect of performance development, specifically with respect to expression of fatigue and injury prevention, the advantages of increased lower body strength have received limited attention at the elite level of the game. The primary aim of this cross-sectional investigation was to examine the association between lower body strength and the expression of markers of fatigue as evaluated through muscle damage assessment following match play in professional soccer players. Ten male professional soccer players participated in this investigation (mean ± SD age 26.2 ± 4.3 years, height 181.6 ± 4.8 cm and body mass 78.7 ± 6.1 kg); creatine kinase (CK) was collected 2-days post-match for a 5-month period and at three different time points (Phase 1, Phase 2 and Phase 3); muscular strength (e.g. 4 repetition half-squat) was measured 3-day post-match. No significant change in CK and muscular force across three time points was found (F = 0.60, P = 0.56, η(2) = 0.06 and F = 2.65, P = 0.10, η(2) = 0.23, respectively). Muscular force was negatively correlated (moderate to very large) with CK. It can be concluded that players who produce greater lower body force as a result of being stronger in the lower limbs show reduced levels of CK 48 h post-match.

Testing strength and power in soccer players: the application of conventional and traditional methods of assessment.

Soccer is a highly complex sport influenced by many physical, psychological, tactical, and technical factors. In terms of basic physical components, strength and power are considered requisites for many important actions such as tackling, jumping, and shooting. Hence, assessment of strength and power is commonly performed within a soccer club's test battery. The objective is to use valid, reliable, and sensitive measures that allow for trustworthy analysis of the physical characteristics of players. Before any credence can be placed in test results, test's validity, reliability, and sensitivity needs to be established. This will allow practitioners to make informed decisions about test selection. This review examines the reliability, validity, and sensitivity of different strength and power assessments in soccer. The suitability of conventional and functional tests is detailed and the strengths and weaknesses of isokinetic dynamometry, hand-held dynamometry (HHD), repetition maximum, and power testing are also addressed. Generally, the tests considered in this review provide moderate to high reliability in soccer players of different training level. Similarly, the consensus demonstrates test methods to be sensitive to training interventions. In comparison, test validity seems less established. Isokinetic dynamometry has often been recognized as a gold standard measure of testing strength. Other methods of assessment are emerging as viable options (e.g., HHD), likely due to functionality and suitability of testing. Given the demands within a soccer club setting, practitioners should endeavor to use testing procedures that are informative yet not time consuming or labor intensive. By providing this, practitioners may have the option to perform more regular monitoring throughout the season rather than a limited number of specific time periods.

Acute responses of soccer match play on hip strength and flexibility measures: potential measure of injury risk.

Regular measurements of groin risk factors may offer a preventive measure against injury. Therefore, the aim of this study was to (1) determine minimal detectable change (MDC) and reliability of hip flexibility and strength measures and to (2) identify the effect soccer match play load has on these measures. Reliability was determined for bent knee fall out test, hip abduction and adduction (hand-held dynamometry (HHD)) in 20 trained youth male soccer players. Reliability was evaluated with the intra-class correlation coefficient (ICC[2,1]), 95% confidence intervals (CI). Hip strength and flexibility measures were taken before and after an international friendly match. Intra-rater reliability ICC ranges were bent knee fall out (0.75-0.90), abduction (0.83-0.90) and adduction (0.72-0.96). Inter-rater ICCs (95% CI) were bent knee fall out test [0.75 (0.39-0.90) right, 0.71 (0.27-0.89) left hip]; abduction [0.80 (0.50-0.92) right, 0.81 (0.53-0.92) left hip] and adduction [0.72 (0.31-0.89) right, 0.70 (0.26-0.88) left hip]. MDCs were as low as 20.7% of the mean for hip flexibility and 12.5% for strength. In conclusion, HHD and the bent knee fall out test are reliable tools to measure changes in hip strength and flexibility. Finally, a threshold may exist in which match play load negatively impacts hip flexibility.

Effect of an injury prevention program on muscle injuries in elite professional soccer.

Due to the continual physical, physiological, and psychological demands of elite level soccer increasing the incidence and risk of injuries, preventative training programs have become a common feature of soccer players training schedule. The aim of the current investigation was to examine the effectiveness of a structured injury prevention program on the number of muscle injuries and the total number of injuries within elite professional soccer. The present study was conducted over 2 consecutive seasons, of which the first (2008-2009) being the intervention season and the second the control season (2009-2010). In total, 26 and 23 elite male professional soccer players competing within the Scottish Premier League and European competition participated. The training program was performed twice weekly for the entirety of the season (58 prevention sessions). The results revealed an increase in the total number of injuries within the intervention season (88 vs. 72); however, this was largely due to the greater number of contusion injuries sustained within the intervention season (n = 44) when compared with control season (n = 23). Significantly less muscle injuries were observed during the intervention season (moderate effect), and this occurred concomitant with a bigger squad size (large effect, p < 0.001). The findings from this study identify that a multicomponent injury prevention-training program may be appropriate for reducing the number of muscle injuries during a season but may not be adequate to reduce all other injuries.

Effects of a periodized small-sided game training intervention on physical performance in elite professional soccer.

The present study examined the effects of periodized small-sided game (SSG) training intervention during a 4-week in-season break on the physical performance changes (i.e., speed, aerobic performance, and repeated sprint ability) within elite European soccer players. Fifteen, elite, male, professional players (age: 24.5 ± 3.45 years; height: 181.1 ± 5.78 cm; body mass: 78.7 ± 7.67 kg; VO2max: 54.88 ± 5.25 ml·kg(-1)·min(-1)) from a Scottish Premier League team participated in 7 separate SSG sessions (3 vs. 3 plus goalkeepers) of which games lasted for a 3-minute duration for the selected number of games (ranged from 5 to 11) increasing over the intervention period. To examine the effects of the SSG intervention on physical performance changes, pre- and posttesting sessions took place over a 2-day period (day 1: anthropometry and repeated sprint ability [RSA] assessments; day 2: running economy [RE] and blood lactate assessments). Results show that the 4-week SSG training intervention induced significant improvement in RSA as indicated by faster 10-m sprint time (p < 0.05, small effect), total sprint time (p < 0.05, medium effect), and smaller percentage decrement score (p < 0.05, medium effect). Furthermore, the SSGs also led to an improvement in RE as indicated through significantly reduced VO2 and heart rate at running speed 9, 11, and 14 km·h(-1) (all p's < 0.05, large effects). In conclusion, the present study demonstrates that implementing a periodized SSG training intervention during the 4-week in-season break is capable of improving elite-level soccer players' physical fitness characteristics. Being able to develop physical characteristics in conjunction to technical and tactical elements of the game, within a relatively short period, makes SSGs an appealing proposition for fitness coaches, players, and technical coaches alike.

Shared Decision-Making: Some cautionary observations in the context of elite sport.

The concept of shared decision-making (SDM) has emerged as a key component in the return to play interface as a hallmark of good practice that is athlete focused and allows greater engagement from the athlete. SDM is an appealing, well-intentioned framework that would seemingly lend itself to effectively being implemented. However, in this editorial, we have identified concerns surrounding the social complexities of elite sports and the difficulties of truly applying this concept in practice. In what follows, we explain the dynamics associated, discuss the importance of context when considering the efficacy of this practice and lastly offer what we see as certain key issues that might impede effective SDM.

The effect of playing formation on high-intensity running and technical profiles in English FA Premier League soccer matches.

The aim of this study was to examine the effect of playing formation on high-intensity running and technical performance during elite soccer matches. Twenty English FA Premier League games were analysed using a multiple-camera computerized tracking system (n = 153 players). Overall ball possession did not differ (P < 0.05) between 4-4-2, 4-3-3 and 4-5-1 formations (50%, s = 7 vs. 49%, s = 8 vs. 44%, s = 6). No differences were observed in high-intensity running between 4-4-2, 4-3-3 and 4-5-1 formations. Compared with 4-4-2 and 4-3-3 formations, players in a 4-5-1 formation performed less very high-intensity running when their team was in possession (312 m, s = 196 vs. 433 m, s = 261 vs. 410 m, s = 270; P 5 0.05) but more when their team was not in possession (547 m, s = 217 vs. 461 m, s = 156 vs. 459 m, s = 169; P < 0.05). Attackers in a 4-3-3 performed ~30% more (P < 0.05) high-intensity running than attackers in 4-4-2 and 4-5-1 formations. However, the fraction of successful passes was highest in a 4-4-2 (P < 0.05) compared with 4-3-3 and 4-5-1 formations. The results suggest that playing formation does not influence the overall activity profiles of players, except for attackers, but impacts on very high-intensity running activity with and without ball possession and some technical elements of performance.

Factors Influencing the Association Between Coach and Athlete Rating of Exertion: a Systematic Review and Meta-analysis.

BACKGROUND: Subjective monitoring of rate of perceived exertion is common practice in many sports. Typically, the information is used to understand the training load and at times modify forthcoming sessions. Identifying the relationship between the athlete and coach's interpretation of training would likely further benefit understanding load management. The aim of this systematic review was to evaluate the relationship between coaches' rating of intended exertion (RIE) and/or rating of observed exertion (ROE) and athletes' reported rating of perceived exertion (RPE). METHODS: The review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We conducted a search of Medline, Google Scholar, Science Direct, SPORTDiscus, and Web of Science databases. We assessed the correlation between coach-reported RIE and/or ROE and RPE. Assessment for risk of bias was undertaken using the Quality Appraisal for Reliability Studies (QAREL) checklist. Inclusion criteria were (1) male and/or female individuals, (2) individual and/or team sport active participants, and (3) original research article published in the English language. RESULTS: Data from 19 articles were found to meet the eligibility criteria. A random effect meta-analysis based on 11 studies demonstrated a positive association of player vs. coach rating of RIE (r = 0.62 [95% CI 0.5 to 0.7], p < 0.001). The pooled correlation from 7 studies of player vs. coach rating on ROE was r = 0.64 95% CI (0.5 to 0.7), p < 0.001. CONCLUSION: There was a moderate to high association between coach RIE and/or ROE and athlete-reported RPE and this association seems to be influenced by many factors. The suggestions we present in this review are based on imploring practitioners to consider a multi-modal approach and the implications of monitoring when using RPE. TRIAL REGISTRATION: CRD42020193387.

The Use of Recovery Strategies in Professional Soccer: A Worldwide Survey.

PURPOSE: To survey soccer practitioners' recovery strategy: (1) use, (2) perceived effectiveness, and (3) factors influencing their implementation in professional soccer. METHODS: A cross-sectional convenience sample of professional soccer club/confederation practitioners completed a web-based survey (April to July 2020). Pearson chi-square and Fisher exact tests with Cramer V (φ - c) assessed relationships and their strength, respectively, between the perceived effectiveness and frequency of strategy use. RESULTS: A total of 80 soccer practitioners (13 countries) completed the survey. The 3 most important recovery objectives were "alleviating muscle damage/fatigue," "minimizing injury risk," and "performance optimization." The most frequently used strategies were active recovery, structured recovery day, extra rest day, massage, cold-water therapy, and carbohydrate provision (predominantly on match day and match day + 1). Relationships were identified between perceived effectiveness and frequency of strategy use for sleep medication (P < .001, φ - c = 0.48), carbohydrate provision (P = .007, φ - c = 0.60), protein provision (P = .007, φ - c = 0.63), an extra rest day (P < .001, φ - c = 0.56), and a structured recovery day (P = .049, φ - c = 0.50). CONCLUSIONS: The study demonstrates that professional soccer practitioners have a range of objectives geared toward enhancing player recovery. A disconnect is apparent between the perceived effectiveness of many recovery strategies and their frequency of use in an applied setting. Novel data indicate that strategies are most frequently employed around match day. Challenges to strategy adoption are mainly competing disciplinary interests and resource limitations. Researchers and practitioners should liaise to ensure that the complexities involved with operating in an applied environment are elucidated and apposite study designs are adopted, in turn, facilitating the use of practically effective and compatible recovery modalities.

Motion analysis of match-play in elite U12 to U16 age-group soccer players.

The aim of this study was to quantify the motion demands of match-play in elite U12 to U16 age-group soccer players. Altogether, 112 players from two professional soccer clubs at five age-group levels (U12-U16) were monitored during competitive matches (n = 14) using a 5 Hz non-differential global positioning system (NdGPS). Velocity thresholds were normalized for each age-group using the mean squad times for a flying 10 m sprint test as a reference point. Match performance was reported as total distance, high-intensity distance, very high-intensity distance, and sprint distance. Data were reported both in absolute (m) and relative (m · min(-1)) terms due to a rolling substitute policy. The U15 (1.35 ± 0.09 s) and U16 (1.31 ± 0.06 s) players were significantly quicker than the U12 (1.58 ± 0.10 s), U13 (1.52 ± 0.07 s), and U14 (1.51 ± 0.08 s) players in the flying 10 m sprint test (P < 0.001). The U16 age-group covered significantly more absolute total distance (U16 > U12, U13, U14), high-intensity distance (U16 > U12, U13, U14, U15), very high-intensity distance (U16 > U12, U13), and sprint distance (U16 > U12, U13) than their younger counterparts (P < 0.05). When the data are considered relative to match exposure, few differences are apparent. Training prescription for youth soccer players should consider the specific demands of competitive match-play in each age-group.

Change of Direction Assessment Following Anterior Cruciate Ligament Reconstruction: A Review of Current Practice and Considerations to Enhance Practical Application.

Change of direction (CoD) has been indicated as a key mechanism in the occurrence of anterior cruciate ligament (ACL) injury during invasion sports. Despite these associations, assessments of knee function in athletic populations at the time of return to sport following ACL reconstruction (ACLr) have often focused on strength and single-leg hop tests, with a paucity of evidence to describe the CoD characteristics. Therefore, the aim of this narrative review was to describe the movement strategies exhibited following ACLr during CoD tasks and to critically analyze the range of tests that have been used. Specifically, we examined their ability to identify between-limb deficits and individuals who display a heightened risk of secondary injury and/or reductions in their level of pre-injury performance. MEDLINE, PubMed and SPORT Discuss databases were used and 13 articles were identified that met the inclusion criteria. Examination of the available literature indicates that current field-based practices are not representative of relevant sport demands and are unable to effectively assess knee function following ACLr. Laboratory-based studies have identified residual deficits and altered movement strategies at the time of return to sport, and this in part may be related to risk of re-injury. However, these assessments exhibit inherent limitations and are not practically viable for monitoring progress during rehabilitation. Consequently, alternative solutions that are more-aligned with the multitude of factors occurring during CoD maneuvers in chaotic sports environments are warranted to allow practitioners to 'bridge the gap' between the laboratory and the sports field/court. This approach may facilitate a more informed decision-making process with the end goal being, a heightened 'return to performance' and a lower risk of re-injury.

The Effects of a Single Versus Three Consecutive Sessions of Football Training on Postprandial Lipemia: a Randomized, Controlled Trial in Healthy, Recreationally Active Males.

BACKGROUND: Exercise frequency is important for maintaining health; however, its effects on postprandial responses remain largely unknown. Better understanding this during popular sports activities such as football may influence exercise habits. Therefore, the aim of the present study was to examine the effects of playing one single versus three consecutive days of 60-min small-sided football matches on postprandial lipemia. METHODS: Fifteen males performed either one (1FOOT; n = 7) or three 60-min football (3FOOT; n = 8) sessions across an 8-day trial period. On day 1, a blood sample was collected at fasted (0 min) and 0.75, 2, 4, 6 h after a high-fat meal. Participants were then randomly allocated to the 1FOOT (day 7) or 3FOOT (days 5, 6, 7) condition. On day 8, they repeated the high-fat meal and blood sampling for 6 h following the meal. Postprandial total and incremental area under the curve (AUC, iAUC, respectively) were calculated. RESULTS: The postprandial triglyceride iAUC was 41% lower from pre- to post-measures for the 1FOOT (p < 0.05; ES = 1.02) and 15.7% lower for the 3FOOT (ns; ES = 0.41). Total triglyceride AUC was lower (26%) post-football matches in the 3FOOT group only (p < 0.01; ES = 1.23). In 3FOOT, insulin concentration was lower for post- compared to pre-measures at 0.75 and 2 h, respectively (p < 0.001). CONCLUSION: One single 60-min small-sided football match lowered postprandial TG incremental area under the curve while performing three consecutive days of football matches did not result in a greater attenuation. TRIAL REGISTRATION: ISRCTN17934193 , registered 06 April 2019.

Match-Related Time Course of Perceived Recovery in Youth Football Players.

PURPOSE: To examine the reproducibility of the Perceived Recovery Status (PRS) scale in football players and describe the time course of the PRS in response to a football match. METHODS: Twenty trained youth players (mean [SD] age = 16.2 [1.2] y, height = 1.75 [0.07] m, body mass = 64.0 [7.8] kg) took part in the study. PRS was collected -2 h and -30 min before and +15 min, +3 h, and +24 h after an international football match. Players were categorized into 2 groups based on their playing time (≤45 and 90 min). RESULTS: Reproducibility of the PRS was high (intraclass correlation coefficient = .83, typical error = 0.59, coefficient of variation = 9.9%) between the 2 prematch measures. Overall, PRS was lower at +15 min (4.0 [1.5]; P < .01, effect size = 2.2) and +3 h (4.7 [1.6]; P < .01, effect size = 1.5) compared with -30 min (7.1 [1.3]); +15 min was lower than +24 h (6.1 [1.3]; P < .01, effect size = 1.5). No differences between groups for PRS scores at any of the time points were found. CONCLUSIONS: The PRS is a reproducible tool for monitoring perceptions of recovery to football activity and is sensitive to time-course changes relating to a match. The scale is an easy and efficient tool that can be used to monitor an aspect of recovery.

The effect of a concentrated period of soccer-specific fitness training with small-sided games on physical fitness in youth players.

BACKGROUND: It is unknown whether a concentrated period of small-sided games and high intensity training is an effective training approach in youth soccer players. The aim of the study was to examine the effect of a concentrated period of soccer specific training on physical fitness in youth players. METHODS: Nineteen male soccer players, from two teams, participated (mean age: 16.2±0.8 years; body mass: 58.2±7.6 kg; height: 170.8±7.7 cm). One team performed 5 days of small-sided games and high intensity training (SSG & HIT; N.=12) and the other team regular soccer training with 1 day of SSG and HIT (REG; N.=7) weekly for 4 weeks. The 30-15 intermittent fitness test (30-15 IFT), countermovement jump (CMJ) and change of direction (COD) performance were measured pre and post intervention. Heart rate (HR) and rating of perceived exertion (RPE) were recorded and session load calculated (RPE x minutes). RESULTS: Average percentage of maximum HR and session load were 83% and 344 AU for the SSG & HIT versus 73% and 253 AU for the REG (P<0.05). 30-15 IFT improved for the SSG & HIT (from 17.0±1.1 to 18.4±0.8 km/h; P<0.05; ES=0.57) with no difference for the REG group (Pre: 17.9±1.3, Post: 18.2±1.6 km/h, ES=0.10). CMJ and COD were unchanged in both groups and no injuries were reported. CONCLUSIONS: A 4-week concentrated period of daily SSG & HIT is effective for improving endurance performance in youth soccer players. This was without injuries and without negating performance in power and change of direction.

Postprandial lipaemia 10 and 34 hours after playing football: Does playing frequency affect the response?

Elevated postprandial triglyceride (TG) is associated with increased risk of cardiovascular disease. The time window for the last bout beneficial effect on postprandial lipaemia after football play is unknown. The aim of the present study was to examine whether playing affects postprandial TG during 1.5 day of reduced activity. Eighteen males were randomly allocated to perform either 1 (1FOOT; n = 9; age = 33.0 ± 5.0 yrs; body mass index = 24.2 ± 3.6 kg/m2) or 3 (3FOOT) consecutive days of 60-min 5 vs 5 football (n = 9; age = 32.8 ± 5.2 yrs; body mass index = 26.2 ± 4.1 kg/m2) matches across a 5-day study period. They arrived to the laboratory 10 hrs and 34 hrs after the final football session and blood samples were collected at fasted (0 min) and 45, 90, 240 and 360 min post a high fat load meal. There were non significant increase for postprandial TG AUC (9.1%; p = 0.17; 95%CI = -0.43 to 2.0; ES = -0.23) and iAUC (14.2%; p = 0.43; 95%CI = -0.92 to 1.9; ES = -0.24) between 10 and 34 hrs after the 1FOOT. For the 3FOOT, there was a non significant decrease in postprandial TG AUC (-2.7%; p = 0.73; 95%CI = -2.0 to 1.5; ES = 0.05) and iAUC (-17.5%; p = 0.41; 95%ci = -2.5 to 1.1; ES = 0.31) from 10 to 34 hrs, respectively. Performing three consecutive days of football exercise may offer no greater protective effect for postprandial TG before a period of reduced activity, compared to a single session.

Does Early Recruitment Predict Greater Physical Performance in Academy Soccer Players?

The purpose of this longitudinal study was to investigate whether recruitment status influences neuromuscular and endurance performances in academy soccer players over a 2-year training period (from Under-16 to Under-18). Thirty-seven male soccer players from an elite academy were selected and divided in two cohorts according to their recruitment status: Early Recruitment group (ER; n = 16), training and competing for the academy since Under-14 and Under-15 age groups, and; Late Recruitment group (LR; n = 21) included in the academy training process at Under-16. Squat (SJ) and countermovement jump with (CMJwA) and without arms swing (CMJ), 10-m sprint time, and Vam-Eval test (MAV) were performed in three successive occasions always pre-season (Under-16, Under-17 and Under-18 age groups, T1, T2, and T3 respectively). A two-way (recruitment status × time) analysis of variance with repeated measurements was performed as well as the magnitude of difference using both effect size and magnitude-based inferences. There was no difference between ER and LR for MAV, 10 m-sprint, and SJ from T1 to T3. However, LR players presented non-significant small and possibly greater improvement in CMJ (ES = 0.4) and CMJwA (ES = 0.4) than ER players at T2. These data indicate that early recruitment is not likely to result in greater physical performance improvement at the age of 18.

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.

Agility in Team Sports: Testing, Training and Factors Affecting Performance.

BACKGROUND: Agility is an important characteristic of team sports athletes. There is a growing interest in the factors that influence agility performance as well as appropriate testing protocols and training strategies to assess and improve this quality. OBJECTIVE: The objective of this systematic review was to (1) evaluate the reliability and validity of agility tests in team sports, (2) detail factors that may influence agility performance, and (3) identify the effects of different interventions on agility performance. METHODS: The review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We conducted a search of PubMed, Google Scholar, Science Direct, and SPORTDiscus databases. We assessed the methodological quality of intervention studies using a customized checklist of assessment criteria. RESULTS: Intraclass correlation coefficient values were 0.80-0.91, 0.10-0.81, and 0.81-0.99 for test time using light, video, and human stimuli. A low-level reliability was reported for youth athletes using the video stimulus (0.10-0.30). Higher-level participants were shown to be, on average, 7.5% faster than their lower level counterparts. Reaction time and accuracy, foot placement, and in-line lunge movement have been shown to be related to agility performance. The contribution of strength remains unclear. Efficacy of interventions on agility performance ranged from 1% (vibration training) to 7.5% (small-sided games training). CONCLUSIONS: Agility tests generally offer good reliability, although this may be compromised in younger participants responding to various scenarios. A human and/or video stimulus seems the most appropriate method to discriminate between standard of playing ability. Decision-making and perceptual factors are often propositioned as discriminant factors; however, the underlying mechanisms are relatively unknown. Research has focused predominantly on the physical element of agility. Small-sided games and video training may offer effective methods of improving agility, although practical issues may hinder the latter.