The match-to-match variation of match-running in elite female soccer.

PubMed

Trewin, Joshua; Meylan, César; Varley, Matthew C; Cronin, John

2018-02-01

The purpose of this study was to examine the match-to-match variation of match-running in elite female soccer players utilising GPS, using full-match and rolling period analyses. Longitudinal study. Elite female soccer players (n=45) from the same national team were observed during 55 international fixtures across 5 years (2012-2016). Data was analysed using a custom built MS Excel spreadsheet as full-matches and using a rolling 5-min analysis period, for all players who played 90-min matches (files=172). Variation was examined using co-efficient of variation and 90% confidence limits, calculated following log transformation. Total distance per minute exhibited the smallest variation when both the full-match and peak 5-min running periods were examined (CV=6.8-7.2%). Sprint-efforts were the most variable during a full-match (CV=53%), whilst high-speed running per minute exhibited the greatest variation in the post-peak 5-min period (CV=143%). Peak running periods were observed as slightly more variable than full-match analyses, with the post-peak period very-highly variable. Variability of accelerations (CV=17%) and Player Load (CV=14%) was lower than that of high-speed actions. Positional differences were also present, with centre backs exhibiting the greatest variation in high-speed movements (CV=41-65%). Practitioners and researchers should account for within player variability when examining match performances. Identification of peak running periods should be used to assist worst case scenarios. Whilst micro-sensor technology should be further examined as to its viable use within match-analyses. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Sport activities differentiating match-play improvement in elite youth footballers - a 2-year longitudinal study.

PubMed

Güllich, Arne; Kovar, Peter; Zart, Sebastian; Reimann, Ansgar

2017-02-01

This study examined contributions of different types of sport activities to the development of elite youth soccer performance. Match-play performance of 44 German male players was assessed by expert coaches twice, 24 months apart (age 11.1-13.1 years), based on videotaped 5v5 matches. Player pairs were matched by identical age and initial performance at t 1 . Each player was assigned to a group of either "Strong" or "Weak Responders" based on a higher or lower subsequent performance improvement at t 2 within each pair (mean Δperformance 29% vs. 7%). A questionnaire recorded current and earlier amounts of organised practice/training and non-organised sporting play, in soccer and other sports, respectively. Group comparison revealed that "Strong Responders" accumulated more non-organised soccer play and organised practice/training in other sports, but not more organised soccer practice/training. Subsequent multivariate analyses (multiple linear regression analyses (MLR)) highlighted that higher resultant match-play performance at t 2 was accounted for R 2 adj  = 0.65 by performance at t 1 , together with more non-organised soccer play and organised engagement in other sports, respectively, and greater current, but less earlier volume of organised soccer. The findings suggest that variable early sporting experience facilitates subsequent soccer performance development in German elite youth footballers.

Maximal Sprinting Speed of Elite Soccer Players During Training and Matches.

PubMed

Djaoui, Leo; Chamari, Karim; Owen, Adam L; Dellal, Alexandre

2017-06-01

The aim of the present study was to compare (a) the maximal sprinting speed (MSS) attained by soccer players during matches (MSSmatch) according to their level of play (professional first French division vs. elite amateur fourth French division) and the playing positions and (b) the MSS attained by professional soccer players during 14 different types of small-sided games (SSG, MSSSSG) and match-play. All players monitored through the study performed a 40-m sprint test to assess individual MSS (MSStest) and compare it to the training and match activity, with the calculation of the percentage of MSStest (%MSStest) reached. No differences were found according to the level of play; however, positional wide players achieved a higher MSSmatch, %MSStest, and MSSSSG than central players (both defenders and midfielders) during matches and SSG. MSSmatch were higher than all MSSSSG, and MSSSSG were positively correlated with the area of the pitch (0.45, p < 0.001), its length (0.53, p < 0.001), and the number of players involved (0.38, p < 0.001). The closer SSG was to match situation in terms of rules, the higher the MSSSSG. Wide players reached higher MSS in match and SSG than central players, confirming the relevance of using SSG close to match situation to specifically prepare elite players to the maximal running speed demand of the match.

Match running performance and fitness in youth soccer.

PubMed

Buchheit, M; Mendez-Villanueva, A; Simpson, B M; Bourdon, P C

2010-11-01

The activity profiles of highly trained young soccer players were examined in relation to age, playing position and physical capacity. Time-motion analyses (global positioning system) were performed on 77 (U13-U18; fullbacks [FB], centre-backs [CB], midfielders [MD], wide midfielders [W], second strikers [2 (nd)S] and strikers [S]) during 42 international club games. Total distance covered (TD) and very high-intensity activities (VHIA; >16.1 km·h (-1)) were computed during 186 entire player-matches. Physical capacity was assessed via field test measures (e. g., peak running speed during an incremental field test, VVam-eval). Match running performance showed an increasing trend with age ( P<0.001, partial eta-squared (η (2)): 0.20-0.45). When adjusted for age and individual playing time, match running performance was position-dependent ( P<0.001, η (2): 0.13-0.40). MD covered the greater TD; CB the lowest ( P<0.05). Distance for VHIA was lower for CB compared with all other positions ( P<0.05); W and S displayed the highest VHIA ( P<0.05). Relationships between match running performance and physical capacities were position-dependent, with poor or non-significant correlations within FB, CB, MD and W (e. g., VHIA vs. VVam-eval: R=0.06 in FB) but large associations within 2 (nd)S and S positions (e. g., VHIA vs. VVam-eval: R=0.70 in 2 (nd)S). In highly trained young soccer players, the importance of fitness level as a determinant of match running performance should be regarded as a function of playing position.

Monitoring of Post-match Fatigue in Professional Soccer: Welcome to the Real World.

PubMed

Carling, Christopher; Lacome, Mathieu; McCall, Alan; Dupont, Gregory; Le Gall, Franck; Simpson, Ben; Buchheit, Martin

2018-05-08

Participation in soccer match-play leads to acute and transient subjective, biochemical, metabolic and physical disturbances in players over subsequent hours and days. Inadequate time for rest and regeneration between matches can expose players to the risk of training and competing whilst not entirely recovered. In professional soccer, contemporary competitive schedules can require teams to compete in excess of 60 matches over the course of the season with periods of fixture congestion occurring, prompting much attention from researchers and practitioners to the monitoring of fatigue and readiness to play. A comprehensive body of research has investigated post-match acute and residual fatigue responses. Yet the relevance of the research for professional soccer contexts is debatable, notably in relation to the study populations and designs employed. Monitoring can indeed be invasive, expensive, time inefficient, and difficult to perform routinely and simultaneously in a large squad of regularly competing players. Uncertainty also exists regarding the meaningfulness and interpretation of changes in fatigue response values and their functional relevance, and practical applicability in the field. The real-world need and cost-benefit of monitoring must be carefully weighed up. In relation to professional soccer contexts, this opinion paper intends to (1) debate the need for post-match fatigue monitoring; (2) critique the real-world relevance of the current research literature; (3) discuss the practical burden relating to measurement tools and protocols, and the collection, interpretation and application of data in the field; and (4) propose future research perspectives.

Longitudinal development of match-running performance in elite male youth soccer players.

PubMed

Saward, C; Morris, J G; Nevill, M E; Nevill, A M; Sunderland, C

2016-08-01

This study longitudinally examined age-related changes in the match-running performance of retained and released elite youth soccer players aged 8-18 years. The effect of playing position on age-related changes was also considered. Across three seasons, 263 elite youth soccer players were assessed in 1-29 competitive matches (988 player-matches). For each player-match, total distance and distances covered at age group-specific speed zones (low-speed, high-speed, sprinting) were calculated using 1 Hz or 5 Hz GPS. Mixed modeling predicted that match-running performance developed nonlinearly, with age-related changes best described with quadratic age terms. Modeling predicted that playing position significantly modified age-related changes (P < 0.05) and retained players covered significantly more low-speed distance compared with released players (P < 0.05), by 75 ± 71 m/h (mean ± 95% CI; effect size ± 95% CI: 0.35 ± 0.34). Model intercepts randomly varied, indicating differences between players in match-running performance unexplained by age, playing position or status. These findings may assist experts in developing training programs specific to the match play demands of players of different ages and playing positions. Although retained players covered more low-speed distance than released players, further study of the actions comprising low-speed distance during match play is warranted to better understand factors differentiating retained and released players. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Match Physical Performance of Elite Female Soccer Players During International Competition.

PubMed

Datson, Naomi; Drust, Barry; Weston, Matthew; Jarman, Ian H; Lisboa, Paulo J; Gregson, Warren

2017-09-01

Datson, N, Drust, B, Weston, M, Jarman, IH, Lisboa, P, and Gregson, W. Match physical performance of elite female soccer players during international competition. J Strength Cond Res 31(9): 2379-2387, 2017-The purpose of this study was to provide a detailed analysis of the physical demands of competitive international female soccer match play. A total of 148 individual match observations were undertaken on 107 outfield players competing in competitive international matches during the 2011-2012 and 2012-2013 seasons, using a computerized tracking system (Prozone Sports Ltd., Leeds, England). Total distance and total high-speed running distances were influenced by playing position, with central midfielders completing the highest (10,985 ± 706 m and 2,882 ± 500 m) and central defenders the lowest (9,489 ± 562 m and 1,901 ± 268 m) distances, respectively. Greater total very high-speed running distances were completed when a team was without (399 ± 143 m) compared to with (313 ± 210 m) possession of the ball. Most sprints were over short distances with 76% and 95% being less than 5 and 10 m, respectively. Between half reductions in physical performance were present for all variables, independent of playing position. This study provides novel findings regarding the physical demands of different playing positions in competitive international female match play and provides important insights for physical coaches preparing elite female players for competition.

Effect of playing tactics on goal scoring in Norwegian professional soccer.

PubMed

Tenga, Albin; Holme, Ingar; Ronglan, Lars Tore; Bahr, Roald

2010-02-01

Methods that include an assessment of opponent interactions are thought to provide a more valid analysis of team match performance. The purpose of this study was to examine the effect of playing tactics on goal scoring by assessing opponent interactions in Norwegian elite soccer. The sample included 203 team possessions leading to goals (cases) and 1688 random team possessions (control group) from 163 of 182 (90%) matches played in the men's professional league during the 2004 season. Multidimensional qualitative data using ten ordered categorical variables were obtained to characterize each team possession. The proportion of goals scored during counterattacks (52%) was higher than during elaborate attacks (48%), while for the control group the proportion using elaborate attacks (59%) was higher than when using counterattacks (41%) (P = 0.002). Multiple logistic regression analyses showed that, for the main variable "team possession type", counterattacks were more effective than elaborate attacks when playing against an imbalanced defence (OR = 1.64; 95% confidence interval: 1.03 to 2.61; P = 0.038). Assessment of opponent interactions is critical to evaluate the effectiveness of offensive playing tactics on the probability of scoring goals, and improves the validity of team match-performance analysis in soccer.

Influence of carbohydrate supplementation on skill performance during a soccer match simulation.

PubMed

Russell, Mark; Benton, David; Kingsley, Michael

2012-07-01

This study investigated the influence of carbohydrate supplementation on skill performance throughout exercise that replicates soccer match-play. Experimentation was conducted in a randomised, double-blind and cross-over study design. After familiarization, 15 professional academy soccer players completed a soccer match simulation incorporating passing, dribbling and shooting on two separate occasions. Participants received a 6% carbohydrate-electrolyte solution (CHO) or electrolyte solution (PL). Precision, success rate, ball speed and an overall index (speed-precision-success; SPS) were determined for all skills. Blood samples were taken at rest, immediately before exercise, every 15 min during exercise (first half: 15, 30 and 45 min; second half: 60, 75 and 90 min), and 10 min into the half time (half-time). Carbohydrate supplementation influenced shooting (time×treatment interaction: p<0.05), where CHO attenuated the decline in shot speed and SPS index. Supplementation did not affect passing or dribbling. Blood glucose responses to exercise were influenced by supplementation (time×treatment interaction: p<0.05), where concentrations were higher at 45 min and during half-time in CHO compared with PL. Blood glucose concentrations reduced by 30±1% between half-time and 60 min in CHO. Carbohydrate supplementation attenuated decrements in shooting performance during simulated soccer match-play; however, further research is warranted to optimise carbohydrate supplementation regimes for high-intensity intermittent sports. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Variety Wins: Soccer-Playing Robots and Infant Walking

PubMed Central

Ossmy, Ori; Hoch, Justine E.; MacAlpine, Patrick; Hasan, Shohan; Stone, Peter; Adolph, Karen E.

2018-01-01

Although both infancy and artificial intelligence (AI) researchers are interested in developing systems that produce adaptive, functional behavior, the two disciplines rarely capitalize on their complementary expertise. Here, we used soccer-playing robots to test a central question about the development of infant walking. During natural activity, infants' locomotor paths are immensely varied. They walk along curved, multi-directional paths with frequent starts and stops. Is the variability observed in spontaneous infant walking a “feature” or a “bug?” In other words, is variability beneficial for functional walking performance? To address this question, we trained soccer-playing robots on walking paths generated by infants during free play and tested them in simulated games of “RoboCup.” In Tournament 1, we compared the functional performance of a simulated robot soccer team trained on infants' natural paths with teams trained on less varied, geometric paths—straight lines, circles, and squares. Across 1,000 head-to-head simulated soccer matches, the infant-trained team consistently beat all teams trained with less varied walking paths. In Tournament 2, we compared teams trained on different clusters of infant walking paths. The team trained with the most varied combination of path shape, step direction, number of steps, and number of starts and stops outperformed teams trained with less varied paths. This evidence indicates that variety is a crucial feature supporting functional walking performance. More generally, we propose that robotics provides a fruitful avenue for testing hypotheses about infant development; reciprocally, observations of infant behavior may inform research on artificial intelligence. PMID:29867427

Variety Wins: Soccer-Playing Robots and Infant Walking.

PubMed

Ossmy, Ori; Hoch, Justine E; MacAlpine, Patrick; Hasan, Shohan; Stone, Peter; Adolph, Karen E

2018-01-01

Although both infancy and artificial intelligence (AI) researchers are interested in developing systems that produce adaptive, functional behavior, the two disciplines rarely capitalize on their complementary expertise. Here, we used soccer-playing robots to test a central question about the development of infant walking. During natural activity, infants' locomotor paths are immensely varied. They walk along curved, multi-directional paths with frequent starts and stops. Is the variability observed in spontaneous infant walking a "feature" or a "bug?" In other words, is variability beneficial for functional walking performance? To address this question, we trained soccer-playing robots on walking paths generated by infants during free play and tested them in simulated games of "RoboCup." In Tournament 1, we compared the functional performance of a simulated robot soccer team trained on infants' natural paths with teams trained on less varied, geometric paths-straight lines, circles, and squares. Across 1,000 head-to-head simulated soccer matches, the infant-trained team consistently beat all teams trained with less varied walking paths. In Tournament 2, we compared teams trained on different clusters of infant walking paths. The team trained with the most varied combination of path shape, step direction, number of steps, and number of starts and stops outperformed teams trained with less varied paths. This evidence indicates that variety is a crucial feature supporting functional walking performance. More generally, we propose that robotics provides a fruitful avenue for testing hypotheses about infant development; reciprocally, observations of infant behavior may inform research on artificial intelligence.

Are Soccer Matches Badly Designed Experiments?

NASA Technical Reports Server (NTRS)

Skinner, G. K.; Freeman, G. H.

2008-01-01

Models in which the number of goals scored by a team in a soccer match follow a Poisson distribution, or a closely related one. have been widely discussed. We here consider a soccer match as an experiment to assess which of two teams is superior and examine the probability that the outcome of the experiment (match) truly represents the relative abilities of the two teams. Given a final score it is possible by using a Bayesian approach to quantify the probability that it was or was not the case that 'the best team won'. For typical scores, the probability of a misleading result is significant. Modifying the rules of the game to increase the typical number of goals scored would improve the situation, but a level of confidence that would normally be regarded as satisfactory could not be obtained unless the character of the game were radically changed.

Effect of 2 soccer matches in a week on physical performance and injury rate.

PubMed

Dupont, Gregory; Nedelec, Mathieu; McCall, Alan; McCormack, Derek; Berthoin, Serge; Wisløff, Ulrik

2010-09-01

Recovery duration may be too short during the congested fixtures of professional soccer players with regard to maintaining physical performance and a low injury rate. To analyze the effects of 2 matches per week on physical performance and injury rate in male elite soccer players. Cohort study; Level of evidence, 3. Match results, match-related physical performance, and injuries were monitored during 2 seasons (2007-2008 and 2008-2009) for 32 professional soccer players in a top-level team participating in the UEFA (Union of European Football Associations) Champions League. Total distance, high-intensity distance, sprint distance, and number of sprints were collected for 52 home matches. Injuries and player participation in matches and training were recorded throughout the full season. Physical performance, as characterized by total distance covered, high-intensity distance, sprint distance, and number of sprints, was not significantly affected by the number of matches per week (1 versus 2), whereas the injury rate was significantly higher when players played 2 matches per week versus 1 match per week (25.6 versus 4.1 injuries per 1000 hours of exposure; P < .001). The recovery time between 2 matches, 72 to 96 hours, appears sufficient to maintain the level of physical performance tested but is not long enough to maintain a low injury rate. The present data highlight the need for player rotation and for improved recovery strategies to maintain a low injury rate among athletes during periods with congested match fixtures.

Relationships Between Internal and External Match-Load Indicators in Soccer Match Officials.

PubMed

Castillo, Daniel; Weston, Matthew; McLaren, Shaun J; Cámara, Jesús; Yanci, Javier

2017-08-01

The aims of this study were to describe the internal and external match loads (ML) of refereeing activity during official soccer matches and to investigate the relationship among the methods of ML quantification across a competitive season. A further aim was to examine the usefulness of differential perceived exertion (dRPE) as a tool for monitoring internal ML in soccer referees. Twenty field referees (FRs) and 43 assistant referees (ARs) participated in the study. Data were collected from 30 competitive matches (FR = 20 observations, AR = 43 observations) and included measures of internal (Edwards' heart-rate-derived training impulse [TRIMP EDW ]) ML, external (total distance covered, distance covered at high speeds, and player load) ML, and ML differentiated ratings of perceived respiratory (sRPE res ) and leg-muscle (sRPE mus ) exertion. Internal and external ML were all greater for FRs than for ARs (-19.7 to -72.5), with differences ranging from very likely very large to most likely extremely large. The relationships between internal-ML and external-ML indicators were, in most cases, unclear for FR (r < .35) and small to moderate for AR (r < .40). The authors found substantial differences between RPE res and RPE mus scores in both FRs (0.6 AU; ±90% confidence limits 0.4 AU) and ARs (0.4; ±0.3). These data demonstrate the multifaceted demands of soccer refereeing and thereby highlight the importance of monitoring both internal and external ML. Moreover, dRPE represents distinct dimensions of effort and may be useful in monitoring soccer referees' ML during official matches.

The Use of Match Statistics that Discriminate Between Successful and Unsuccessful Soccer Teams

PubMed Central

Castellano, Julen; Casamichana, David; Lago, Carlos

2012-01-01

Three soccer World Cups were analysed with the aim of identifying the match statistics which best discriminated between winning, drawing and losing teams. The analysis was based on 177 matches played during the three most recent World Cup tournaments: Korea/Japan 2002 (59), Germany 2006 (59) and South Africa 2010 (59). Two categories of variables were studied: 1) those related to attacking play: goals scored, total shots, shots on target, shots off target, ball possession, number of off-sides committed, fouls received and corners; and 2) those related to defence: total shots received, shots on target received, shots off target received, off-sides received, fouls committed, corners against, yellow cards and red cards. Discriminant analysis of these matches revealed the following: (a) the variables related to attacking play that best differentiated between winning, drawing and losing teams were total shots, shots on target and ball possession; and (b) the most discriminating variables related to defence were total shots received and shots on target received. These results suggest that winning, drawing and losing national teams may be discriminated from one another on the basis of variables such as ball possession and the effectiveness of their attacking play. This information may be of benefit to both coaches and players, adding to their knowledge about soccer performance indicators and helping to guide the training process. PMID:23487020

Physiological and performance effects of carbohydrate gels consumed prior to the extra-time period of prolonged simulated soccer match-play.

PubMed

Harper, Liam D; Briggs, Marc A; McNamee, Ged; West, Daniel J; Kilduff, Liam P; Stevenson, Emma; Russell, Mark

2016-06-01

The physiological and performance effects of carbohydrate-electrolyte gels consumed before the 30min extra-time period of prolonged soccer-specific exercise were investigated. Randomised, double-blind, crossover. Eight English Premier League academy soccer players performed 120min of soccer-specific exercise on two occasions while consuming fluid-electrolyte beverages before exercise, at half-time and 90min. Carbohydrate-electrolyte (0.7±0.1gkg(-1) BM) or energy-free placebo gels were consumed ∼5min before extra-time. Blood samples were taken before exercise, at half-time and every 15min during exercise. Physical (15-m and 30-m sprint speed, 30-m sprint maintenance and countermovement jump height) and technical (soccer dribbling) performance was assessed throughout each trial. Carbohydrate-electrolyte gels improved dribbling precision (+29±20%) and raised blood glucose concentrations by 0.7±0.8mmoll(-1) during extra-time (both p<0.01). Supplementation did not affect sprint velocities (15m and 30m), 30-m sprint maintenance or dribbling speed as reductions compared to 0-15min values occurred at 105-120min irrespective of trial (all p<0.05). Plasma osmolality and blood sodium concentrations increased post-exercise vs. the opening 15min (p<0.05) but no effect of supplementation existed. Selected markers of physical performance (jump height, 30-m sprint velocity and 30-m repeated sprint maintenance) also reduced by >3% during half-time (all p<0.05). Carbohydrate-electrolyte gel ingestion raised blood glucose concentrations and improved dribbling performance during the extra-time period of simulated soccer match-play. Supplementation did not attenuate reductions in physical performance and hydration status that occurred during extra-time. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Influence of different types of compression garments on exercise-induced muscle damage markers after a soccer match.

PubMed

Marqués-Jiménez, Diego; Calleja-González, Julio; Arratibel-Imaz, Iñaki; Delextrat, Anne; Uriarte, Fernando; Terrados, Nicolás

2018-01-01

There is not enough evidence of positive effects of compression therapy on the recovery of soccer players after matches. Therefore, the objective was to evaluate the influence of different types of compression garments in reducing exercise-induced muscle damage (EIMD) during recovery after a friendly soccer match. Eighteen semi-professional soccer players (24 ± 4.07 years, 177 ± 5 cm; 71.8 ± 6.28 kg and 22.73 ± 1.81 BMI) participated in this study. A two-stage crossover design was chosen. Participants acted as controls in one match and were assigned to an experimental group (compression stockings group, full-leg compression group, shorts group) in the other match. Participants in experimental groups played the match wearing the assigned compression garments, which were also worn in the 3 days post-match, for 7 h each day. Results showed a positive, but not significant, effect of compression garments on attenuating EIMD biomarkers response, and inflammatory and perceptual responses suggest that compression may improve physiological and psychological recovery.

Variability of soccer referees' match performances.

PubMed

Weston, M; Drust, B; Atkinson, G; Gregson, W

2011-03-01

The aim of the present study was to determine the between-match variability in soccer referees' match performances. 1 269 individual match observations were undertaken on 59 referees (range 2-79 games per referee) officiating in the English Premier League and Championship from 2003/2004 to 2007/2008 using a computerised tracking system (Prozone (®), Leeds, England). Between-match coefficients of variation (CV) were calculated for all games and then compared between referee age and experience groups. High mean CVs were observed for high-speed running distance (25.9±10.1%), recovery time (32.7±13.8%), explosive sprints (34.3±16.6%), total number of sprints (54.0±20.7%) and number of match fouls (28±4.6%). Smaller CVs were observed for total distance covered (3.8±1.5%), top sprinting speed (5.6±10.9%), distance from the ball (4.2±1.9%) and the distance from fouls (9.9±4.3%). Variability in match activities was not influenced by referee age or experience. The present study's findings demonstrate that variability in soccer referees' match performances is high in some variables and not dependent on referee age or experience. Such variability means that research requires large sample sizes to detect real systematic changes in a number of performance characteristics when studied during matches. © Georg Thieme Verlag KG Stuttgart · New York.

The Effect of Carbohydrate Ingestion on Performance during a Simulated Soccer Match

PubMed Central

Goedecke, Julia H.; White, Nicholas J.; Chicktay, Waheed; Mahomed, Hafsa; Durandt, Justin; Lambert, Michael I.

2013-01-01

Aim: This study investigated how performance was affected after soccer players, in a postprandial state, ingested a 7% carbohydrate (CHO) solution compared to a placebo (0% CHO) during a simulated soccer match. Methods: Using a double-blind placebo-controlled design, 22 trained male league soccer players (age: 24 ± 7 years, wt: 73.4 ± 12.0 kg, VO2max: 51.8 ± 4.3 mL O2/kg/min) completed two trials, separated by 7 days, during which they ingested, in random order, 700 mL of either a 7% CHO or placebo drink during a simulated soccer match. Ratings of perceived exertion (RPE), agility, timed and run to fatigue were measured during the trials. Results: Change in agility times was not altered by CHO vs. placebo ingestion (0.57 ± 1.48 vs. 0.66 ± 1.00, p = 0.81). Timed runs to fatigue were 381 ± 267 s vs. 294 ± 159 s for the CHO and placebo drinks, respectively (p = 0.11). Body mass modified the relationship between time to fatigue and drink ingestion (p = 0.02 for drink × body mass), such that lower body mass was associated with increased time to fatigue when the players ingested CHO, but not placebo. RPE values for the final stage of the simulated soccer match were 8.5 ± 1.7 and 8.6 ± 1.5 for the CHO and placebo drinks respectively (p = 0.87). Conclusions: The group data showed that the 7% CHO solution (49 g CHO) did not significantly improve performance during a simulated soccer match in league soccer players who had normal pre-match nutrition. However, when adjusting for body mass, increasing CHO intake was associated with improved time to fatigue during the simulated soccer match. PMID:24352094

The effect of carbohydrate ingestion on performance during a simulated soccer match.

PubMed

Goedecke, Julia H; White, Nicholas J; Chicktay, Waheed; Mahomed, Hafsa; Durandt, Justin; Lambert, Michael I

2013-12-16

This study investigated how performance was affected after soccer players, in a postprandial state, ingested a 7% carbohydrate (CHO) solution compared to a placebo (0% CHO) during a simulated soccer match. Using a double-blind placebo-controlled design, 22 trained male league soccer players (age: 24 ± 7 years, wt: 73.4 ± 12.0 kg, VO2max: 51.8 ± 4.3 mL O2/kg/min) completed two trials, separated by 7 days, during which they ingested, in random order, 700 mL of either a 7% CHO or placebo drink during a simulated soccer match. Ratings of perceived exertion (RPE), agility, timed and run to fatigue were measured during the trials. Change in agility times was not altered by CHO vs. placebo ingestion (0.57 ± 1.48 vs. 0.66 ± 1.00, p = 0.81). Timed runs to fatigue were 381 ± 267 s vs. 294 ± 159 s for the CHO and placebo drinks, respectively (p = 0.11). Body mass modified the relationship between time to fatigue and drink ingestion (p = 0.02 for drink × body mass), such that lower body mass was associated with increased time to fatigue when the players ingested CHO, but not placebo. RPE values for the final stage of the simulated soccer match were 8.5 ± 1.7 and 8.6 ± 1.5 for the CHO and placebo drinks respectively (p = 0.87). The group data showed that the 7% CHO solution (49 g CHO) did not significantly improve performance during a simulated soccer match in league soccer players who had normal pre-match nutrition. However, when adjusting for body mass, increasing CHO intake was associated with improved time to fatigue during the simulated soccer match.

Is Heading in Youth Soccer Dangerous Play?

PubMed

O'Kane, John W

2016-01-01

Soccer is among the most popular youth sports with over 3 million youth players registered in the U.S. Soccer is unique in that players intentionally use their head to strike the ball, leading to concerns that heading could cause acute or chronic brain injury, especially in the immature brains of children. Pub Med search without date restriction was conducted in November 2014 and August 2015 using the terms soccer and concussion, heading and concussion, and youth soccer and concussion. 310 articles were identified and reviewed for applicable content specifically relating to youth athletes, heading, and/or acute or chronic brain injury from soccer. Soccer is a low-risk sport for catastrophic head injury, but concussions are relatively common and heading often plays a role. At all levels of play, concussions are more likely to occur in the act of heading than with other facets of the game. While concussion from heading the ball without other contact to the head appears rare in adult players, some data suggests children are more susceptible to concussion from heading primarily in game situations. Contributing factors include biomechanical forces, less developed technique, and the immature brain's susceptibility to injury. There is no evidence that heading in youth soccer causes any permanent brain injury and there is limited evidence that heading in youth soccer can cause concussion. A reasonable approach based on U.S. Youth Soccer recommendations is to teach heading after age 10 in controlled settings, and heading in games should be delayed until skill acquisition and physical maturity allow the youth player to head correctly with confidence.

Energy demands in competitive soccer.

PubMed

Bangsbo, J

1994-01-01

In elite outfield players, the average work rate during a soccer match, as estimated from variables such as heart rate, is approximately 70% of maximal oxygen uptake (VO2 max). This corresponds to an energy production of approximately 5700 kJ (1360 kcal) for a person weighing 75 kg with a VO2 max of 60 ml kg-1 min-1. Aerobic energy production appears to account for more than 90% of total energy consumption. Nevertheless, anaerobic energy production plays an essential role during soccer matches. During intensive exercise periods of a game, creatine phosphate, and to a lesser extent the stored adenosine triphosphate, are utilized. Both compounds are partly restored during a subsequent prolonged rest period. In blood samples taken after top-class soccer matches, the lactate concentration averages 3-9 mM, and individual values frequently exceed 10 mM during match-play. Furthermore, the adenosine diphosphate degradation products--ammonia/ammonium, hypoxanthine and uric acid--are elevated in the blood during soccer matches. Thus, the anaerobic energy systems are heavily taxes during periods of match-play. Glycogen in the working muscle seems to be the most important substrate for energy production during soccer matches. However, muscle triglycerides, blood free fatty acids and glucose are also used as substrates for oxidative metabolism in the muscles.

A 15-year prospective epidemiological account of acute traumatic injuries during official professional soccer league matches in Japan.

PubMed

Aoki, Haruhito; O'Hata, Nozomu; Kohno, Terushige; Morikawa, Tsuguo; Seki, Jun

2012-05-01

Few prospective epidemiological studies on soccer match injuries have collected continuous data using subjects from the same group. To investigate long-term injury-induced changes during official matches in the professional Japanese soccer league. Descriptive epidemiological study. Acute injuries during official matches among top-division Japanese professional soccer leaguers were prospectively collected from 1993 to 2007. Injuries preventing player participation for 7 days or more were defined as a reportable injury. Interseasonal variations of injury rate (IR: injuries/1000/player hours) and injury pattern (type, location, circumstances, severity, injury time, positional role, and relationship to weather) were analyzed. Throughout the study period, 2947 injuries from 3984 matches occurred. Mean annual IR was 21.77/1000 player hours, and annual variance showed gradual decrement throughout the study period. The proportion of injury type and location were not significantly changed. Sprain and contusion as injury type and thigh and ankle joint as location were the most common in every season. Contact-related injuries comprised 73.3% on average and were observed to occur more frequently during the last 15 minutes and extra time of match play. The proportion of foul play-related injuries showed a clear declining trend. The proportion of severe injury showed a sporadic increase from 2001 to 2004. The second, fifth, and sixth 15-minute match segments showed a higher IR. Goalkeepers had a lower IR versus other field players. Matches on rainy days resulted in a lower IR than did those held under other weather conditions. Long-term surveillance and statistical feedback of injury characteristics to organization members were considered effective in improving safer play awareness among players and for referees to reduce injury incidence, particularly foul play-related injuries.

Effects of Static Stretching and Playing Soccer on Knee Laxity.

PubMed

Baumgart, Christian; Gokeler, Alli; Donath, Lars; Hoppe, Matthias W; Freiwald, Jürgen

2015-11-01

This study investigated exercise-induced effects of static stretching and playing soccer on anterior tibial translation (ATT) of the knee joint. Randomized controlled trial. University biomechanics laboratory. Thirty-one athletes were randomly assigned into a stretching (26.9 ± 6.2 years, 1.77 ± 0.09 m, 67.9 ± 10.7 kg) and a control group (27.9 ± 7.4 years, 1.75 ± 0.08 m, 72.0 ± 14.9 kg). Thirty-one amateur soccer players in an additional soccer group (25.1 ± 5.6 years, 1.74 ± 0.10 m, 71.8 ± 14.8 kg). All participants had no history of knee injury requiring surgery and any previous knee ligament or cartilage injury. The stretching group performed 4 different static stretching exercises with a duration of 2 × 20 seconds interspersed with breaks of 10 seconds. The soccer group completed a 90-minute soccer-specific training program. The control group did not perform any physical activity for approximately 30 minutes. Anterior tibial translation was measured with the KT-1000 knee arthrometer at forces of 67 N, 89 N, and maximal manual force (Max) before and after the intervention. There was a significant increase in ATT after static stretching and playing soccer at all applied forces. Maximal manual testing revealed a mean increase of ATT after static stretching of 2.1 ± 1.6 mm (P < 0.0005) and after playing soccer of 1.0 ± 1.5 mm (P = 0.001). The ATT increase after static stretching at 67 and 89 N is significantly higher than in controls. At maximum manual testing, significant differences were evident between all groups. Static stretching and playing soccer increase ATT and may consequently influence mechanical factors of the anterior cruciate ligament. The ATT increase after static stretching was greater than after playing soccer. The observed increase in ATT after static stretching and playing soccer may be associated with changes in kinesthetic perception and sensorimotor control, activation of muscles, joint stability, overall performance, and higher

Variability of GPS-derived running performance during official matches in elite professional soccer players.

PubMed

Al Haddad, Hani; Méndez-Villanueva, Alberto; Torreño, Nacho; Munguía-Izquierdo, Diego; Suárez-Arrones, Luis

2017-09-22

The aim of this study was to assess the match-to-match variability obtained using GPS devices, collected during official games in professional soccer players. GPS-derived data from nineteen elite soccer players were collected over two consecutive seasons. Time-motion data for players with more than five full-match were analyzed (n=202). Total distance covered (TD), TD >13-18 km/h, TD >18-21 km/h, TD >21 km/h, number of acceleration >2.5-4 m.s-2 and >4 m.s-2 were calculated. The match-to-match variation in running activity was assessed by the typical error expressed as a coefficient of variation (CV,%) and the magnitude of the CV was calculated (effect size). When all players were pooled together, CVs ranged from 5% to 77% (first half) and from 5% to 90% (second half), for TD and number of acceleration >4 m.s-2, and the magnitude of the CVs were rated from small to moderate (effect size = 0.57-0.98). The CVs were likely to increase with running/acceleration intensity, and were likely to differ between playing positions (e.g., TD > 13-18 km/h 3.4% for second strikers vs 14.2% for strikers and 14.9% for wide-defenders vs 9.7% for wide-midfielders). Present findings indicate that variability in players' running performance is high in some variables and likely position-dependent. Such variability should be taken into account when using these variables to prescribe and/or monitor training intensity/load. GPS-derived match-to-match variability in official games' locomotor performance of professional soccer players is high in some variables, particularly for high-speed running, due to the complexity of match running performance and its most influential factors and reliability of the devices.

Variability of Metabolic Power Data in Elite Soccer Players During Pre-Season Matches

PubMed Central

Hoppe, Matthias Wilhelm; Baumgart, Christian; Slomka, Mirko; Polglaze, Ted; Freiwald, Jürgen

2017-01-01

Abstract This study aimed to determine the within-subject variability of GPS-derived metabolic power data in elite soccer players across several pre-season matches and compare the variability of high metabolic power, velocity, acceleration and deceleration running. Additionally, differences in metabolic power data among playing positions and relationships with various physical abilities were also investigated. Metabolic power data from 12 outfield starting players competing in the German Bundesliga were collected during five pre-season matches using GPS-technology (10 Hz). The players were also tested for speed, agility, power and intermittent endurance. Variability of global metabolic power data such as energy expenditure (CV = 2.2-7.0%) was lower than that for high-intensity including time ≥20 W·kg-1 (CV = 14.0-26.2%). Variability of high metabolic power (≥20 W·kg-1; CV = 14.1 ± 3.5%) was comparable to that of high velocity (≥15.5 km·h-1; CV = 17.0 ± 6.2%), acceleration (≥3 m·s-2; CV = 11.1 ± 5.1%) and deceleration running (≤-3 m·s-2; CV = 11.9 ± 4.5%) (p > 0.05, ES < 0.2). Defenders had a largely higher overall energy expenditure than midfielders and attackers (p < 0.01, ES > 0.6). Overall energy expenditure and cost were largely to very largely correlated with 5 m speed and 22 m agility sprint time and counter movement jump height (r = -0.70-0.69, p < 0.05). The detected variability indicates that global GPS-derived metabolic power data in elite soccer players from a single preseason match should be preferably used for practical applications. Contrary, high-intensity indicators should be interpreted cautiously and repeated match observations are recommended to establish meaningful high-intensity profiles of the players. Differences among playing positions and relationships with explosive physical abilities indicate that metabolic power analyses can provide new insights into the mechanics and energetics of soccer. PMID:28828094

Variability of Metabolic Power Data in Elite Soccer Players During Pre-Season Matches.

PubMed

Hoppe, Matthias Wilhelm; Baumgart, Christian; Slomka, Mirko; Polglaze, Ted; Freiwald, Jürgen

2017-09-01

This study aimed to determine the within-subject variability of GPS-derived metabolic power data in elite soccer players across several pre-season matches and compare the variability of high metabolic power, velocity, acceleration and deceleration running. Additionally, differences in metabolic power data among playing positions and relationships with various physical abilities were also investigated. Metabolic power data from 12 outfield starting players competing in the German Bundesliga were collected during five pre-season matches using GPS-technology (10 Hz). The players were also tested for speed, agility, power and intermittent endurance. Variability of global metabolic power data such as energy expenditure (CV = 2.2-7.0%) was lower than that for high-intensity including time ≥20 W·kg -1 (CV = 14.0-26.2%). Variability of high metabolic power (≥20 W·kg -1 ; CV = 14.1 ± 3.5%) was comparable to that of high velocity (≥15.5 km·h -1 ; CV = 17.0 ± 6.2%), acceleration (≥3 m·s -2 ; CV = 11.1 ± 5.1%) and deceleration running (≤-3 m·s -2 ; CV = 11.9 ± 4.5%) (p > 0.05, ES < 0.2). Defenders had a largely higher overall energy expenditure than midfielders and attackers (p < 0.01, ES > 0.6). Overall energy expenditure and cost were largely to very largely correlated with 5 m speed and 22 m agility sprint time and counter movement jump height (r = -0.70-0.69, p < 0.05). The detected variability indicates that global GPS-derived metabolic power data in elite soccer players from a single preseason match should be preferably used for practical applications. Contrary, high-intensity indicators should be interpreted cautiously and repeated match observations are recommended to establish meaningful high-intensity profiles of the players. Differences among playing positions and relationships with explosive physical abilities indicate that metabolic power analyses can provide new insights into the mechanics and energetics of soccer.

English soccer teams' aggressive behavior when playing away from home.

PubMed

Thomas, Sion; Reeves, Colin; Smith, Andrew

2006-04-01

Speculation about key factors affecting home advantage still exists. The present study investigated aggressive behavior amongst English Football Premiership (soccer) players and its relation to home advantage. The frequency of aggressive behaviour, identified by the award of a penalty or disciplinary card (yellow for caution or red for dismissal) was analysed over 2000-2003. Chi-square analyses assessed whether a greater frequency of aggressive behavior was performed by teams away from home. In decided matches, teams playing away received significantly more cautions (yellow cards) than home teams. A further analysis of tied matches indicated that away teams received significantly more cautions (yellow cards) than home teams. No significant differences between home and away teams were found for dismissals and penalties awarded. Reasons for these findings are considered.

Circadian variation and soccer performance: implications for training and match-play during Ramadan.

PubMed

Drust, B; Ahmed, Q; Roky, R

2012-01-01

Ramadan results in a number of behavioural alterations in individuals when compared to their normal habits outside of this holy month. These changes in behaviour could impact upon the effectiveness of the activity of an elite athlete who has high daily activity levels and energy expenditures. Understanding the true impact of Ramadan on human physiology will also require an awareness of the key aspects of circadian rhythms. This article will present theoretical background content on circadian rhythms along with data on the potential influence of circadian variation on soccer performance. It will also attempt to provide an insight into the problems of partial sleep deprivation and travel for the elite player. The contents will suggest that there is a basis for the within-day variation in physiological and psychological function to impact soccer performance if games are played early in the day or very late at night. As competitive fixtures are uncommon at these times these influences may be more relevant to the timing and organisation of training sessions. It is also likely that a lack of sleep and excessive travel will provide conditions that are not conducive to optimal performance. This would indicate that teams should think carefully about their preparation strategies for important tournaments and games.

Impact of Official Matches on Soccer Referees' Power Performance.

PubMed

Castillo, Daniel; Yanci, Javier; Cámara, Jesús

2018-03-01

The evaluation of match officials' neuromuscular performance is now an important consideration and the vertical jump test is considered suitable for assessing lower limb power, partly because it is directly related to refereeing. The aim of this study, therefore, was to determine the effect of soccer matches on match officials' vertical jump performance by assessing various biomechanical variables. Eighteen field referees (FRs) and 36 assistant referees (ARs) who officiated in 18 official matches participated in this study. Before the match, at half time and immediately after the match, officials performed two countermovement jumps. Flight phase time (FT), maximum force production (MFpropulsion), time to production of maximum force (TMFpropulsion), production of maximum power (MP), maximum landing force (MFlanding) and time to stabilization (TTS) were calculated for all jumps. There was a tendency for match officials' jumping performance to improve after matches than beforehand (FR: effect size (ES) = 0.19 ± 0.36, possibly trivial; AR: ES = 0.07 ± 0.17, likely trivial). There were also likely small and very likely moderate differences between FRs' MP in pre-match and half-time jumps (ES = 0.46 ± 0.47) and in their pre- and post-match jumps (ES = 0.71 ± 0.48). These results indicate that refereeing soccer matches does not reduce vertical jump performance; the subsequent neuromuscular fatigue is not sufficient to affect landing technique.

Neuromuscular demand in a soccer match assessed by a continuous electromyographic recording.

PubMed

Montini, Marco; Felici, Francesco; Nicolò, Andrea; Sacchetti, Massimo; Bazzucchi, Ilenia

2017-04-01

The bulk of research investigating soccer player's performance has been concentrated on the metabolic demand, while only few studies focused on the neuromuscular activation. The present study aimed at investigating the activation profile of the leg muscles throughout a 90- minute soccer match. Fifteen football players (18.3±0.7 years) performed: 1) an isometric maximal voluntary contraction (MVC) before the game [MVCpre]; 2) a 90-minute soccer match (composed of two 45-minute periods separated by a 15-minute rest); 3) a second MVC after the match [MVCpost]. Electromyographic (EMG) activity of the Vastus Lateralis (VL) muscle of the dominant leg was recorded during the match. The root mean square (RMS) of the EMG signals was normalized for the maximal RMS obtained during the MVCpre (100%RMSmax) and six intensity classes were created in order to represent the %RMS distribution during the match (1st: 0-20%RMSmax; 2nd: 20-40%RMSmax; 3rd: 40-60%RMSmax; 4th: 60-80%RMSmax; 5th: 80-100%RMSmax; 6th: 100-120%RMSmax). After the 90-minute soccer match, knee extensor MVC failed to show any statistical difference from pre-game values (-4.2%; P>0.05) whilst the neuromuscular activation demonstrated a significant reduction (-26.3%, P<0.01). During the game, the mean total distribution of RMS of the players was: 84.8±7.1% of total time in the 1st class, 8.5±3.9% in the 2nd, 3.6±1.6% in the 3rd, 1.7±1.0% in the 4th, 0.9±0.6% in the 5th and 0.4±0.5% in the 6th class of intensity. There was a significant difference (P<0.05) between the first versus the second half for the classes 1st, 3rd and 4th. This represents the first attempt to characterize the neuromuscular activation profile during a 90-minute soccer match. Integrating this approach with more traditional ones may help further our understanding of the physiological demand of competitive soccer.

Changes in the lipid profile of elite basketball and soccer players after a match.

PubMed

Apostolidis, N; Bogdanis, G C; Kostopoulos, N; Souglis, A; Papadopoulos, Ch

2014-01-01

The lipid profile of elite basketball and soccer athletes was evaluated and compared with that of inactive individuals. Total cholesterol (T-C), low and high density lipoprotein cholesterol (LDL-C and HDL-C), and triglyceride (TG) concentration were measured in the morning and after a soccer or a basketball match. All parameters of lipid profile measured at a fasted and resting state, except HDL-C, were lower in the athletes compared with the controls (p < 0.01). The soccer match resulted in a greater decrease in TG (78.3 ± 6.7 to 70.7 ± 6.3, p < 0.01), T-C (179.3 ± 10.7 to 171.6 ± 9.6, p < 0.01), LDL-C (110.9 ± 8.9 to 103.5 ± 7.5, p < 0.01) compared with the basketball match that resulted only in a decrease in LDL-C (126.8 ± 9.5 to 117.3 ± 9.1, p < 0.01) and an increase in HDL-C that was similar to that observed after the soccer match (9-12%). These findings support the beneficial effects of basketball and soccer on cardiovascular health.

Nutrition and Supplementation in Soccer.

PubMed

Oliveira, César Chaves; Ferreira, Diogo; Caetano, Carlos; Granja, Diana; Pinto, Ricardo; Mendes, Bruno; Sousa, Mónica

2017-05-12

Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition).

Nutrition and Supplementation in Soccer

PubMed Central

Oliveira, César Chaves; Ferreira, Diogo; Caetano, Carlos; Granja, Diana; Pinto, Ricardo; Mendes, Bruno; Sousa, Mónica

2017-01-01

Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition). PMID:29910389

Kinetic Post-match Fatigue in Professional and Youth Soccer Players During the Competitive Period

PubMed Central

Djaoui, Leo; Diaz-Cidoncha Garcia, Jorge; Hautier, Christophe; Dellal, Alexandre

2016-01-01

Background No previous research has analysed kinetic fatigue of elite adult players and elite youth players during the competitive period. Objectives The aim of the present study was to analyse kinetic post-match fatigue in professional and youth soccer players during the competitive period. Materials and Methods resting heart rate (HRrest), post-effort recovery heart rate (HRrecovery), rate of perceived exertion fatigue (RPEf), muscle soreness and blood samples with creatine kinase (CK) and resting lactate (La) from nine professional soccer players were measured immediately before, 24 hour and 48 hour after two official French first league matches (Ligue 1) whereas RPEf, HRrest, and 20m speed performance (speed-20 m) were measured in ten U-17 elite players immediately before, 24 hour and 48h after a friendly match. Results for professionals, a soccer match elevated all physiological markers during the next 24 hours (P < 0.05); only HRrecovery remained significantly different 48 hours after the match (P < 0.05) whereas there was no variation of HRrest, RPEf, and speed-20m, which were elevated until 24h and got back to reference values 48 hours after the match (P < 0.05) for the U17 players. Comparing the two groups, HRrest results remained lower all the time for professionals, and RPEf was lower for U-17, 24 hours after the match (P < 0.05). Conclusions Independent of their level, professional soccer players, need 48 hours to recover after an official match. Professionals gain more fatigue than young players after a match, but recover as fast. Thus, they recover more efficiently especially due to a better physical condition and fitness training. It is expected that the results showed in the study help elite soccer and fitness coaches to manage the training load of the team according to the match. PMID:27217927

The influence of successive matches on match-running performance during an under-23 international soccer tournament: The necessity of individual analysis.

PubMed

Varley, Matthew C; Di Salvo, Valter; Modonutti, Mattia; Gregson, Warren; Mendez-Villanueva, Alberto

2018-03-01

This study investigated the effects of successive matches on match-running in elite under-23 soccer players during an international tournament. Match-running data was collected using a semi-automated multi-camera tracking system during an international under-23 tournament from all participating outfield players. Players who played 100% of all group stage matches were included (3 matches separated by 72 h, n = 44). Differences in match-running performance between matches were identified using a generalised linear mixed model. There were no clear effects for total, walking, jogging, running, high-speed running and sprinting distance between matches 1 and 3 (effect size (ES); -0.32 to 0.05). Positional analysis found that sprint distance was largely maintained from matches 1 to 3 across all positions. Attackers had a moderate decrease in total, jogging and running distance between matches 1 and 3 (ES; -0.72 to -0.66). Classifying players as increasers or decreasers in match-running revealed that match-running changes are susceptible to individual differences. Sprint performance appears to be maintained over successive matches regardless of playing position. However, reductions in other match-running categories vary between positions. Changes in match-running over successive matches affect individuals differently; thus, players should be monitored on an individual basis.

Practical nutritional recovery strategies for elite soccer players when limited time separates repeated matches.

PubMed

Ranchordas, Mayur Krachna; Dawson, Joel T; Russell, Mark

2017-01-01

Specific guidelines that aim to facilitate the recovery of soccer players from the demands of training and a congested fixture schedule are lacking; especially in relation to evidence-based nutritional recommendations. The importance of repeated high level performance and injury avoidance while addressing the challenges of fixture scheduling, travel to away venues, and training commitments requires a strategic and practically feasible method of implementing specific nutritional strategies. Here we present evidence-based guidelines regarding nutritional recovery strategies within the context of soccer. An emphasis is placed on providing practically applicable guidelines for facilitation of recovery when multiple matches are played within a short period of time (i.e. 48 h). Following match-play, the restoration of liver and muscle glycogen stores (via consumption of ~1.2 g⋅kg -1 ⋅h -1 of carbohydrate) and augmentation of protein synthesis (via ~40 g of protein) should be prioritised in the first 20 min of recovery. Daily intakes of 6-10 g⋅kg -1 body mass of carbohydrate are recommended when limited time separates repeated matches while daily protein intakes of >1.5 g⋅kg -1 body mass should be targeted; possibly in the form of multiple smaller feedings (e.g., 6 × 20-40 g). At least 150% of the body mass lost during exercise should be consumed within 1 h and electrolytes added such that fluid losses are ameliorated. Strategic use of protein, leucine, creatine, polyphenols and omega-3 supplements could also offer practical means of enhancing post-match recovery.

Player Load, Acceleration, and Deceleration During Forty-Five Competitive Matches of Elite Soccer.

PubMed

Dalen, Terje; Ingebrigtsen, Jørgen; Ettema, Gertjan; Hjelde, Geir Havard; Wisløff, Ulrik

2016-02-01

The use of time-motion analysis has advanced our understanding of position-specific work rate profiles and the physical requirements of soccer players. Still, many of the typical soccer activities can be neglected, as these systems only examine activities measured by distance and speed variables. This study used triaxial accelerometer and time-motion analysis to obtain new knowledge about elite soccer players' match load. Furthermore, we determined acceleration/deceleration profiles of elite soccer players and their contribution to the players' match load. The data set includes every domestic home game (n = 45) covering 3 full seasons (2009, 2010, and 2011) for the participating team (Rosenborg FC), and includes 8 central defenders (n = 68), 9 fullbacks (n = 83), 9 central midfielders (n = 70), 7 wide midfielders (n = 39), and 5 attackers (A, n = 50). A novel finding was that accelerations contributed to 7-10% of the total player load for all player positions, whereas decelerations contributed to 5-7%. Furthermore, the results indicate that other activities besides the high-intensity movements contribute significantly to the players' total match workload. Therefore, motion analysis alone may underestimate player load because many high-intensity actions are without a change in location at the pitch or they are classified as low-speed activity according to current standards. This new knowledge may help coaches to better understand the different ways players achieve match load and could be used in developing individualized programs that better meet the "positional physical demands" in elite soccer.

Repeated-Sprint Sequences During Female Soccer Matches Using Fixed and Individual Speed Thresholds.

PubMed

Nakamura, Fábio Y; Pereira, Lucas A; Loturco, Irineu; Rosseti, Marcelo; Moura, Felipe A; Bradley, Paul S

2017-07-01

Nakamura, FY, Pereira, LA, Loturco, I, Rosseti, M, Moura, FA, and Bradley, PS. Repeated-sprint sequences during female soccer matches using fixed and individual speed thresholds. J Strength Cond Res 31(7): 1802-1810, 2017-The main objective of this study was to characterize the occurrence of single sprint and repeated-sprint sequences (RSS) during elite female soccer matches, using fixed (20 km·h) and individually based speed thresholds (>90% of the mean speed from a 20-m sprint test). Eleven elite female soccer players from the same team participated in the study. All players performed a 20-m linear sprint test, and were assessed in up to 10 official matches using Global Positioning System technology. Magnitude-based inferences were used to test for meaningful differences. Results revealed that irrespective of adopting fixed or individual speed thresholds, female players produced only a few RSS during matches (2.3 ± 2.4 sequences using the fixed threshold and 3.3 ± 3.0 sequences using the individually based threshold), with most sequences composing of just 2 sprints. Additionally, central defenders performed fewer sprints (10.2 ± 4.1) than other positions (fullbacks: 28.1 ± 5.5; midfielders: 21.9 ± 10.5; forwards: 31.9 ± 11.1; with the differences being likely to almost certainly associated with effect sizes ranging from 1.65 to 2.72), and sprinting ability declined in the second half. The data do not support the notion that RSS occurs frequently during soccer matches in female players, irrespective of using fixed or individual speed thresholds to define sprint occurrence. However, repeated-sprint ability development cannot be ruled out from soccer training programs because of its association with match-related performance.

Influence of oxygen uptake kinetics on physical performance in youth soccer.

PubMed

Doncaster, Greg; Marwood, Simon; Iga, John; Unnithan, Viswanath

2016-09-01

To examine the relationship between oxygen uptake kinetics (VO2 kinetics) and physical measures associated with soccer match play, within a group of highly trained youth soccer players. Seventeen highly trained youth soccer players (age: 13.3 ± 0.4 year, self-assessed Tanner stage: 3 ± 1) volunteered for the study. Players initially completed an incremental treadmill protocol to exhaustion, to establish gaseous exchange threshold (GET) and VO2max (59.1 ± 5.4 mL kg(-1) min(-1)). On subsequent visits, players completed a step transition protocol from rest-moderate-intensity exercise, followed by an immediate transition, and from moderate- to severe-intensity exercise (moderate: 95 % GET, severe: 60 %∆), during which VO2 kinetics were determined. Physical soccer-based performance was assessed using a maximal Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) and via GPS-derived measures of physical soccer performance during soccer match play, three 2 × 20 min, 11 v 11 matches, to gain measures of physical performance during soccer match play. Partial correlations revealed significant inverse relationships between the unloaded-to-moderate transition time constant (tau) and: Yo-Yo IR1 performance (r = -0.58, P = 0.02) and GPS variables [total distance (TD): r = -0.64, P = 0.007, high-speed running (HSR): r = -0.64, P = 0.008 and high-speed running efforts (HSReff): r = -0.66, P = 0.005]. Measures of VO2 kinetics are related to physical measures associated with soccer match play and could potentially be used to distinguish between those of superior physical performance, within a group of highly trained youth soccer players.

How Do Amateur Soccer Referees Destabilize a Match?

ERIC Educational Resources Information Center

Fruchart, Eric; Carton, Annie

2012-01-01

The refereeing system in amateur football is not without weakness. Some referees could be deliberately led to destabilize a match in order to demonstrate their skills in regulating a situation of potential conflict. This has posed an ethical problem to soccer institutions. Our study proposes to focus on this phenomenon by questioning seventy four…

Impact of a soccer match on the cardiac autonomic control of referees.

PubMed

Boullosa, Daniel Alexandre; Abreu, Laurinda; Tuimil, José Luis; Leicht, Anthony Scott

2012-06-01

The purpose of this study was to assess the effect of a soccer match on the cardiac autonomic control of heart rate (HR) in soccer referees. Sixteen Spanish regional and third division referees (11 males: 26 ± 7 years, 74.4 ± 4.1 kg, 178 ± 3 cm, Yo-Yo IR1 ~600-1,560 m; 5 females: 22 ± 3 years, 59.3 ± 4.8 kg, 158 ± 8 cm, Yo-Yo IR1 ~200-520 m) participated with 24-h HR recordings measured with a Polar RS800 during a rest and a match day. Autonomic control of HR was assessed from HR variability (HRV) analysis. Inclusion of a soccer match (92.5% spent at >75% maximum HR) reduced pre-match (12:00-17:00 hours; small to moderate), post-match (19:00-00:00 hours; moderate to almost perfect), and night-time (00:00-05:00 hours; small to moderate) HRV. Various moderate-to-large correlations were detected between resting HRV and the rest-to-match day difference in HRV. The rest-to-match day differences of low and high-frequency bands ratio (LF/HF) and HR in the post-match period were moderately correlated with time spent at different exercise intensities. Yo-Yo IR1 performance was highly correlated with jump capacity and peak lactate, but not with any HRV parameter. These results suggest that a greater resting HRV may allow referees to tolerate stresses during a match day with referees who spent more time at higher intensities during matches exhibiting a greater LF/HF increment in the post-match period. The relationship between match activities, [Formula: see text] and HR recovery kinetics in referees and team sport athletes of different competitive levels remains to be clarified.

Incidence, Mechanisms, and Severity of Match-Related Collegiate Men's Soccer Injuries on FieldTurf and Natural Grass Surfaces: A 6-Year Prospective Study.

PubMed

Meyers, Michael C

2017-03-01

Numerous injuries have been attributed to playing on artificial turf. More recently, newer generations of artificial turf have been developed to duplicate the playing characteristics of natural grass. Although artificial turf has been deemed safer than natural grass in some studies, few long-term studies have been conducted comparing match-related collegiate soccer injuries between the 2 playing surfaces. Collegiate male soccer athletes do not experience any difference in the incidence, mechanisms, or severity of match-related injuries between FieldTurf and natural grass. Cohort study; Level of evidence, 2. Male soccer athletes from 11 universities were evaluated over 6 seasons. Demographic features and predictors included player position, cleat design, player weight, turf age, and environmental factors. Outcomes of interest included injury incidence, injury category, time loss, injury mechanism and situation, type of injury, injury grade and anatomic location, injury severity, head and lower extremity trauma, and elective medical procedures. All match-related injuries were evaluated by the attending head athletic trainer and team physicians on site and subsequently in the physician's office when further follow-up and treatment were deemed necessary. In sum, 765 collegiate games were evaluated for match-related soccer injuries sustained on FieldTurf or natural grass during 6 seasons. Overall, 380 team games (49.7%) were played on FieldTurf versus 385 team games (50.3%) played on natural grass. A total of 722 injuries were documented, with 268 (37.1%) occurring on FieldTurf and 454 (62.9%) on natural grass. Multivariate analysis per 10 team games indicated a significant playing surface effect: F 2,720 = 7.260, P = .001. A significantly lower total injury incidence rate (IIR) of 7.1 (95% CI, 6.6-7.5) versus 11.8 (95% CI, 11.3-12.2; P < .0001) and lower rate of substantial injuries, 0.7 (95% CI, 0.5-1.0) versus 1.9 (95% CI, 1.5-2.3; P < .03), were documented on Field

Monitoring external and internal loads of brazilian soccer referees during official matches.

PubMed

Costa, Eduardo C; Vieira, Caio M A; Moreira, Alexandre; Ugrinowitsch, Carlos; Castagna, Carlo; Aoki, Marcelo S

2013-01-01

This study aimed to assess the external and internal loads of Brazilian soccer referees during official matches. A total of 11 field referees (aged 36.2 ± 7.5 years) were monitored during 35 matches. The external (distance covered, mean and maximal speed) and internal load parameters (session ratings of perceived exertion [RPE] training load [TL], Edwards' TL, and time spent in different heart rate [HR] zones) were assessed in 3-4 matches per referee. External load parameters were measured using a wrist Global Positioning System (GPS) receiver. No differences in distance covered (5.219 ± 205 vs. 5.230 ± 237 m) and maximal speed (19.3 ± 1.0 vs. 19.4 ± 1.4 km·h(-1)) were observed between the halves of the matches (p > 0.05). However, the mean speed was higher in the first half of the matches (6.6 ± 0.4 vs. 6.4 ± 0.3 km·h(-1)) (p < 0.05) than in the second half. The mean HR during the matches was ~89% of HRmax. In ~95% of the matches, the referees demonstrated a HR ≥ 80% of HRmax. Nonetheless, the time spent at 90-100% of HRmax was higher in the first half (59.9 vs. 52.3%) (p < 0.05). Significant correlations between session RPE TL and distance covered at 90-100% of HRmax (r = 0.62) and session RPE TL and maximal speed (r = 0.54) (p < 0.05) were noted. Furthermore, there was a positive correlation between session RPE TL and Edwards' TL (r = 0.61) (p < 0.05). Brazilian soccer referees demonstrated high external and internal load demands during official matches. The portable GPS/HR monitors and session RPE method can provide relevant information regarding the magnitude of the physiological strain during official matches. Key PointsHigh external and internal loads were imposed on Brazilian soccer referees during official matches.There was a high positive correlation between a subjective marker of internal load (session RPE) and parameters of external load (distance covered between 90-100% of HRmax and maximal speed).There was a high positive correlation

Soccer Matches as Experiments - How Often Does the 'Best' Team Win?

NASA Technical Reports Server (NTRS)

Skinner, Gerald K.; Freeman, G. H.

2009-01-01

Models in which the number of goals scored by a team in a soccer match follow a Poisson distribution or a closely related one, have been widely discussed. We here consider a soccer match as an experiment to assess which of two teams is superior and examine the probability that the outcome of the experiment (match) truly represents the relative abilities of the two teams. Given a final score it is possible by using a Bayesian approach to quantify the probability that it was or was not the case that the best team won. For typical scores, the probability of a misleading result is significant. Modifying the rules of the game to increase thc typical number of goals scored would improve the situation, but a level of confidence that would normally be regarded as satisfactory could not be obtained unless the character of the game were radically changed.

Comparison of inflammatory responses to a soccer match between elite male and female players.

PubMed

Souglis, Athanasios G; Papapanagiotou, Angeliki; Bogdanis, Gregory C; Travlos, Antonis K; Apostolidis, Nikolaos G; Geladas, Nikolaos D

2015-05-01

The aim of this study was to compare the inflammatory responses between male and female soccer players for a period of 48 hours after an official match. Blood samples were taken from 83 subjects (22 elite male and 21 elite female soccer players and 20 male and 20 female inactive individuals) in the morning of the game day, immediately after the soccer game and 24 and 48 hours after the match. Average relative exercise intensity during the match was similar in male and female players, as indicated by mean heart rate that was 86.9 ± 4.3 and 85.6 ± 2.3% of maximal heart rate (p = 0.23), respectively. Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) increased 2- to 4-fold above resting values, peaking immediately after the match. C-reactive protein (CRP) and creatine kinase peaked 24 hours after the match. Interleukin 6, CRP, and creatine kinase responses were similar in male and female players, but the peak in TNF-α was 18% higher in male players. Interleukin 6, TNF-α, and CRP at rest were lower in male and female players compared with the control subjects, suggesting a protective effect of regular exercise training regarding the inflammatory profile. The results of this study show that a soccer match induces significant inflammatory responses in both male and female players, with only TNF-α peak values being lower in females. Because of the effects of inflammatory responses on performance and health of the players, it is suggested that coaches and trainers should adjust exercise training programs after a match to promote recovery and protect the athletes' health.

Effects of intermittent-endurance fitness on match performance in young male soccer players.

PubMed

Castagna, Carlo; Impellizzeri, Franco; Cecchini, Emilio; Rampinini, Ermanno; Alvarez, José Carlos Barbero

2009-10-01

The purpose of this study was to examine the effect of specific endurance (Yo-Yo Intermittent recovery test level 1, Yo-Yo IR1) on match performance in male youth soccer. Twenty-one young, male soccer players (age 14.1 +/- 0.2 years) were involved in the study. Players were observed during international championship games of corresponding age categories and completed the Yo-Yo IR1 on a separate occasion. Physical (distance coverage) and physiological match demands were assessed using Global Positioning System technology and heart rate (HR) short-range telemetry, respectively. During the match (two 30-minutes halves), players covered 6,204 +/- 731 m, of which 985 +/- 362 m (16%) were performed at high intensities (speed >13 kmxh, HIA). A significant decrement (3.8%, p = 0.003) in match coverage was evident during the second half. No significant (p = 0.07) difference between halves was observed for HIA (p = 0.56) and sprint (speed >18 kmxh, SPR) distances. During the first and second halves, players attained the 86 +/- 5.5 and 85 +/- 6.0% of HRmax (p = 0.17), respectively. Peak HR during the first and second halves were 100 +/- 4 and 99.4 +/- 4.7% of HRmax, respectively. Yo-Yo IR1 performance (842 +/- 352 m) was significantly related to match HIA (r = 0.77, p < 0.001) and total distance (r = 0.65, p = 0.002). This study's results showed that specific endurance, as determined by Yo-Yo IR1 performance, positively affects physical match performance in male young soccer players. Consequently, the Yo-Yo IR1 test may be regarded as a valid test to assess game readiness and guide training prescription in male youth soccer players.

Trends in aggressive play and refereeing among the top five European soccer leagues.

PubMed

Sapp, Ryan M; Spangenburg, Espen E; Hagberg, James M

2018-06-01

Current trends suggest professional soccer is becoming less aggressive, with England often argued to have the most aggressive of the top European leagues. The purpose of this study was to investigate differences in fouls and cards as indicators of aggressive play in the first divisions of England, France, Germany, Italy, and Spain over the past decade. Number of fouls per match and per yellow card has decreased in all leagues since 2007/08, though attempted tackles per foul has not changed or has increased. A lack of substantial rule changes suggests players have become less aggressive in tackling as opposed to referees becoming more lenient. Total number of fouls and cards per match were consistently lower in the English Premier League, however attempted tackles per foul was higher. The data also demonstrate the notions of home advantage and potentially referee bias, since referees tended to call more fouls and award more cards to away teams. Lastly, number of attempted tackles per foul and yellow cards received exhibited the strongest correlations with final league position across the leagues. In conclusion, our data support that elite European soccer has become less aggressive and the English Premier League is the most aggressive league.

The effect of playing tactics and situational variables on achieving score-box possessions in a professional soccer team.

PubMed

Lago-Ballesteros, Joaquin; Lago-Peñas, Carlos; Rey, Ezequiel

2012-01-01

The aim of this study was to analyse the influence of playing tactics, opponent interaction and situational variables on achieving score-box possessions in professional soccer. The sample was constituted by 908 possessions obtained by a team from the Spanish soccer league in 12 matches played during the 2009-2010 season. Multidimensional qualitative data obtained from 12 ordered categorical variables were used. Sampled matches were registered by the AMISCO PRO system. Data were analysed using chi-square analysis and multiple logistic regression analysis. Of 908 possessions, 303 (33.4%) produced score-box possessions, 477 (52.5%) achieved progression and 128 (14.1%) failed to reach any sort of progression. Multiple logistic regression showed that, for the main variable "team possession type", direct attacks and counterattacks were three times more effective than elaborate attacks for producing a score-box possession (P < 0.05). Team possession originating from the middle zones and playing against less than six defending players (P < 0.001) registered a higher success than those started in the defensive zone with a balanced defence. When the team was drawing or winning, the probability of reaching the score-box decreased by 43 and 53 percent, respectively, compared with the losing situation (P < 0.05). Accounting for opponent interactions and situational variables is critical to evaluate the effectiveness of offensive playing tactics on producing score-box possessions.

Injury risk associated with playing actions during competitive soccer

PubMed Central

Rahnama, N; Reilly, T; Lees, A

2002-01-01

Objective: To assess the exposure of players to injury risk during English Premier League soccer matches in relation to selected factors. Methods: Injury risk was assessed by rating the injury potential of playing actions during competition with respect to (a) type of playing action, (b) period of the game, (c) zone of the pitch, and (d) playing either at home or away. In all, 10 games from the English Premier League 1999–2000 were chosen for analysis. A notation system was used whereby 16 soccer specific playing actions were classified into three categories: those inducing actual injury, those with a potential for injury (graded as mild, moderate, or high), and those deemed to have no potential for injury. The pitch was divided into 18 zones, and the position of each event was recorded along with time elapsed in the game, enabling six 15 minute periods to be defined. Results: Close to 18 000 actions were notated. On average (mean (SD)), 1788 (73) events (one every three seconds), 767 (99) events with injury potential (one every six seconds), and 2 (1) injuries (one every 45 minutes) per game were recorded. An overall injury incidence of 53 per 1000 playing hours was calculated. Receiving a tackle, receiving a "charge", and making a tackle were categorised as having a substantial injury risk, and goal catch, goal punch, kicking the ball, shot on goal, set kick, and heading the ball were all categorised as having a significant injury risk. All other actions were deemed low in risk. The first 15 minutes of each half contained the highest number of actions with mild injury potential, the last 15 minutes having the highest number of actions with moderate injury potential (p<0.01). The first and last 15 minutes of the game had the highest number of actions with high injury potential, although not significant. More actions with mild injury potential occurred in the goal area, and more actions with moderate and high injury potential occurred in the zone adjacent to the

Match-to-match variability in high-speed running activity in a professional soccer team.

PubMed

Carling, Christopher; Bradley, Paul; McCall, Alan; Dupont, Gregory

2016-12-01

This study investigated variability in competitive high-speed running performance in an elite soccer team. A semi-automated tracking system quantified running performance in 12 players over a season (median 17 matches per player, 207 observations). Variability [coefficient of variation (CV)] was compared for total sprint distance (TSD, >25.2 km/h), high-speed running (HSR, 19.8-25.2 km/h), total high-speed running (THSR, ≥19.8 km/h); THSR when the team was in and out of ball possession, in individual ball possession, in the peak 5 min activity period; and distance run according to individual maximal aerobic speed (MAS). Variability for % declines in THSR and distance covered at ≥80% MAS across halves, at the end of play (final 15 min vs. mean for all 15 min periods) and transiently (5 min period following peak 5 min activity period), was analysed. Collectively, variability was higher for TSD versus HSR and THSR and lowest for distance run at ≥80% MAS (CVs: 37.1%, 18.1%, 19.8% and 11.8%). THSR CVs when the team was in/out of ball possession, in individual ball possession and during the peak 5 min period were 31.5%, 26.1%, 60.1% and 23.9%. Variability in THSR declines across halves, at the end of play and transiently, ranged from 37.1% to 142.6%, while lower CVs were observed in these metrics for running at ≥80% MAS (20.9-53.3%).These results cast doubt on the appropriateness of general measures of high-speed activity for determining variability in an elite soccer team, although individualisation of HSR thresholds according to fitness characteristics might provide more stable indicators of running performance and fatigue occurrence.

The effect of an acute sleep hygiene strategy following a late-night soccer match on recovery of players.

PubMed

Fullagar, Hugh; Skorski, Sabrina; Duffield, Rob; Meyer, Tim

2016-01-01

Elite soccer players are at risk of reduced recovery following periods of sleep disruption, particularly following late-night matches. It remains unknown whether improving sleep quality or quantity in such scenarios can improve post-match recovery. Therefore, the aim of this study was to investigate the effect of an acute sleep hygiene strategy (SHS) on physical and perceptual recovery of players following a late-night soccer match. In a randomised cross-over design, two highly-trained amateur teams (20 players) played two late-night (20:45) friendly matches against each other seven days apart. Players completed an SHS after the match or proceeded with their normal post-game routine (NSHS). Over the ensuing 48 h, objective sleep parameters (sleep duration, onset latency, efficiency, wake episodes), countermovement jump (CMJ; height, force production), YoYo Intermittent Recovery test (YYIR2; distance, maximum heart rate, lactate), venous blood (creatine kinase, urea and c-reactive protein) and perceived recovery and stress markers were collected. Sleep duration was significantly greater in SHS compared to NSHS on match night (P = 0.002, d = 1.50), with NSHS significantly less than baseline (P < 0.001, d = 1.95). Significant greater wake episodes occurred on match night for SHS (P = 0.04, d = 1.01), without significant differences between- or within-conditions for sleep onset latency (P = 0.12), efficiency (P = 0.39) or wake episode duration (P = 0.07). No significant differences were observed between conditions for any physical performance or venous blood marker (all P > 0.05); although maximum heart rate during the YYIR2 was significantly higher in NSHS than SHS at 36 h post-match (P = 0.01; d = 0.81). There were no significant differences between conditions for perceptual "overall recovery" (P = 0.47) or "overall stress" (P = 0.17). Overall, an acute SHS improved sleep quantity following a late-night soccer match; albeit without any improvement in physical

How does the past of a soccer match influence its future? Concepts and statistical analysis.

PubMed

Heuer, Andreas; Rubner, Oliver

2012-01-01

Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified.

How Does the Past of a Soccer Match Influence Its Future? Concepts and Statistical Analysis

PubMed Central

Heuer, Andreas; Rubner, Oliver

2012-01-01

Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified. PMID:23226200

Post-match Perceived Exertion, Feeling and Wellness in Professional Soccer Players.

PubMed

Fessi, Mohamed Saifeddin; Moalla, Wassim

2018-01-18

The aim of this study was to assess post-match perceived exertion, feeling and wellness according to the match outcome (winning, drawing or losing) in professional soccer players. Twelve outfield players were followed during 52 official matches where the outcomes (win, draw or lose) were noted. Following each match players completed both a 10-point scale rating of perceived exertion (RPE) and an 11-point scale rating of perceived feeling. Rating of perceived sleep quality, stress, fatigue and muscle soreness were collected separately on a 7-point scale the day following each match. Player RPE was higher by a very largely magnitude following a loss compared to a draw or a win and higher by a small magnitude after a draw compared to a win. Players felt more pleasure after a win compared to a draw or loss and more displeasure after a loss compared to draw. The players reported a largely and moderately better-perceived sleep quality, less stress and fatigue following a win compared to draw or a loss, and a moderately bad-perceived sleep quality, higher stress and fatigue following a draw compared to a loss. In contrast, only a trivial-small change was observed in perceived muscle soreness between all outcomes. Matches outcomes moderately to largely affect RPE, perceived feeling, sleep quality, stress and fatigue whereas perceived muscle soreness remains high regardless of the match outcome. However, winning a match decreases the strain and improves both pleasure and wellness in professional soccer players.

Physical characteristics that predict involvement with the ball in recreational youth soccer.

PubMed

Ré, Alessandro H Nicolai; Cattuzzo, Maria Teresa; Henrique, Rafael Dos Santos; Stodden, David F

2016-09-01

This study examined the relative contribution of age, stage of puberty, anthropometric characteristics, health-related fitness, soccer-specific tests and match-related technical performance to variance in involvements with the ball during recreational 5-a-side small-sided (32 × 15 m) soccer matches. Using a cross-sectional design, 80 healthy male students (14.6 ± 0.5 years of age; range 13.6-15.4) who played soccer recreationally were randomly divided into 10 teams and played against each other. Measurements included height, body mass, pubertal status, health-related fitness (12-min walk/run test, standing long jump, 15-m sprint and sit-ups in 30 s), soccer-specific tests (kicking for speed, passing for accuracy and agility run with and without a ball), match-related technical performance (kicks, passes and dribbles) and involvements with the ball during matches. Forward multiple regression analysis revealed that cardiorespiratory fitness (12-min walk/run test) accounted for 36% of the variance in involvements with the ball. When agility with the ball (zigzag running) and power (standing long jump) were included among the predictors, the total explained variance increased to 62%. In conclusion, recreational adolescent players, regardless of their soccer-specific skills, may increase participation in soccer matches most through physical activities that promote improvement in cardiorespiratory fitness, muscle power and agility.

Between-game variation of physical soccer performance measures in highly trained youth soccer players.

PubMed

Doncaster, Greg; Unnithan, Viswanath

2017-07-12

To assess the between-game variation in measures of physical performance during 11 v 11 soccer match-play, over a short period of time, in highly trained youth soccer players. A single cohort observational study design was employed. Physical match performance data were collected from 17 male, highly trained youth soccer players (age: 13.3 ± 0.4 y) over three, 2 x 20min, 11 v 11 matches. Using 10 Hz GPS, the variables selected for analyses were total distance (TD), high-speed running (HSR), very high-speed running (VHSR), number of high-speed running efforts (HSReff) and number of very high-speed running efforts (VHSReff). Match data was also separated into cumulative 5 min epochs, to identify the peak 5 min epoch and the mean of the cumulative 5 min epochs for each match. Variability was quantified using the coefficient of variation (CV), Standard error of measurement (SEM) and intra-class correlation coefficient (ICC). Between- and within-player smallest worthwhile changes (SWC) were also calculated for each variable to aid in the interpretation of the data. Analysis of the variance between games reported a low CV for TD (3.8%) but larger CVs for HSR (33.3%), HSReff (35.4%) and VHSR and VHSReff (59.6 and 57.4 %, respectively). Analysis of 5 min epochs (peak and average) found an increase in the CVs beyond that of the values reported for the whole match. Between-player SWC in high intensity physical performance data ranged from 24.7 - 42.4 %, whereas within-player SWC ranged from 1.2 - 79.9%. The between-game variability of high and very high intensity activities in youth soccer players, across three soccer matches over a short period of time (2 weeks), is relatively 'large' and specific to the individual, thus highlighting the need for caution when interpreting physical performance data between games and players.

The development of aerobic and skill assessment in soccer.

PubMed

O'Reilly, John; Wong, Stephen H S

2012-12-01

Methods of assessing soccer players' performance have developed significantly in recent times. The fitness profiles and skill levels of a prospective elite soccer player is a valuable resource for coaches in the process of identifying talent. Traditional means to measure aerobic fitness have centred on the 'aerobic capacity' or '&OV0312;O(2max)' test (also known as the maximal oxygen consumption test) but, over time, this has been shown not to be a sensitive measure for specific aspects of soccer in a match situation. Therefore, numerous soccer-specific simulations have been designed to re-create exercise patterns similar to those experienced during a match. Some of these studies have yet to be validated, while others have been shown to result in a similar physiological load to that encountered during regular match play. Further developments have led to specifically designed intermittent sprint tests, which are used as a sensitive tool to accurately measure the fluctuations in players' ability both between and within soccer seasons. Testing procedures have also been developed that incorporate elements of both skill and physical ability. Soccer-specific field tests have been designed, incorporating skill and dynamic movements, and this opens up the possibility of teams testing the aerobic capacity of their elite players using soccer-specific movements. Valid studies assessing soccer-specific skills in an ecologically sound environment have been quite rare until recently. Some test protocols have been deemed largely irrelevant to soccer match play, while others have had limited impact on scientific literature. More recently, skill tests have been developed and shown to be valid and reliable methods of assessing soccer skill performance. Many new skill tests continue to be developed, and some have been shown to be highly reliable, but further study of these relatively novel concepts is required before a more solid recommendation can be made. Overall, while significant

Return to Play and Future ACL Injury Risk Following ACL Reconstruction In Soccer Athletes From the MOON Group

PubMed Central

Brophy, Robert H.; Schmitz, Leah; Wright, Rick W.; Dunn, Warren R.; Parker, Richard D.; Andrish, Jack T.; McCarty, Eric C.; Spindler, Kurt P.

2013-01-01

Background There is limited information on outcomes and return to play (RTP) after ACL reconstruction (ACLR) in soccer athletes. Hypothesis The purpose of this study was to (i) test the hypotheses that player sex, side of injury and graft choice do not influence RTP, and (ii) define the risk for future ACL injury in soccer players after ACLR. Study design Retrospective cohort study, Level II. Methods Soccer players in a prospective cohort were contacted to determine RTP following ACLR. Information regarding if and when they returned to play, their current playing status, the primary reason they stopped playing soccer (if relevant) and incidence of subsequent ACL surgery was recorded. Results Initially, 72% of 100 soccer athletes (55 male, 45 female) with a mean age of 24.2 years at the time of ACL reconstruction returned to soccer. At average follow up of 7.0 years, 36% were still playing, a significant decrease compared to initial RTP (p<0.0001). Based on multivariate analysis, older athletes (p=0.006) and females (p=0.037) were less likely to return to play. Twelve soccer athletes had undergone further ACL surgery, including 9 on the contralateral knee and 3 on the ipsilateral knee. In a univariate analysis, females were more likely to have future ACL surgery (20% v. 5.5%, p=0.03). Soccer athletes who underwent ACLR on their non-dominant limb had a higher future rate of contra-lateral ACLR (16%) than soccer athletes who underwent ACLR on their dominant limb (3.5%) (p=0.03). Conclusion Younger and male soccer players are more likely to return to play after ACL reconstruction. Return to soccer following ACLR declines over time. PMID:23002201

Relative Match Intensities at High Altitude in Highly-Trained Young Soccer Players (ISA3600).

PubMed

Buchheit, Martin; Hammond, Kristal; Bourdon, Pitre C; Simpson, Ben M; Garvican-Lewis, Laura A; Schmidt, Walter F; Gore, Christopher J; Aughey, Robert J

2015-03-01

To compare relative match intensities of sea-level versus high-altitude native soccer players during a 2-week camp at 3600 m, data from 7 sea-level (Australian U17 National team, AUS) and 6 high-altitude (a Bolivian U18 team, BOL) native soccer players were analysed. Two matches were played at sea-level and three at 3600 m on Days 1, 6 and 13. The Yo-Yo Intermittent recovery test (vYo-YoIR1) was performed at sea-level, and on Days 3 and 10. Match activity profiles were measured via 10-Hz GPS. Distance covered >14.4 km.h(-1) (D>14.4 km·h(-1)) and >80% of vYo-YoIR1 (D>80%vYo-YoIR1) were examined. Upon arrival at altitude, there was a greater decrement in vYo-YoIR1 (Cohen's d +1.0, 90%CL ± 0.8) and D>14.4 km·h(-1) (+0.5 ± 0.8) in AUS. D>14.4 km.h(-1) was similarly reduced relative to vYo-YoIR1 in both groups, so that D>80%vYo-YoIR1 remained similarly unchanged (-0.1 ± 0.8). Throughout the altitude sojourn, vYo-YoIR1 and D>14.4 km·h(-1) increased in parallel in AUS, so that D>80%vYo-YoIR1 remained stable in AUS (+6.0%/match, 90%CL ± 6.7); conversely D>80%vYo-YoIR1 decreased largely in BOL (-12.2%/match ± 6.2). In sea-level natives competing at high-altitude, changes in match running performance likely follow those in high-intensity running performance. Bolivian data confirm that increases in 'fitness' do not necessarily translate into greater match running performance, but rather in reduced relative exercise intensity. Key pointsWhen playing at high-altitude, players may alter their activities during matches in relation to their transient maximal physical capacities, possibly to maintain a 'tolerable' relative exercise intensity.While there is no doubt that running performance per se in not the main determinant of match outcomes (Carling, 2013), fitness levels influence relative match intensity (Buchheit et al., 2012, Mendez-Villanueva et al., 2013), which in-turn may impact on decision making and skill performance (Rampinini et al., 2008).In the context of

Association of Physical and Technical Activities With Partial Match Status in a Soccer Professional Team.

PubMed

Moalla, Wassim; Fessi, Mohamed Saieffedin; Makni, Emna; Dellal, Alexandre; Filetti, Cristoforo; Di Salvo, Valter; Chamari, Karim

2018-06-01

Moalla, W, Fessi, MS, Makni, E, Dellal, A, Filetti, C, Di Salvo, V, and Chamari, K. Association of physical and technical activities with partial match status in a soccer professional team. J Strength Cond Res 32(6): 1708-1714, 2018-The purpose of this study was to examine the association between physical and technical activities and partial match status (winning, drawing, or losing) in a professional soccer team over 2 seasons. Physical and technical activities of 52 official matches were collected and analyzed at each 15-minute interval, for each half (45 minutes), and full match (90 minutes) using a multiple-camera computerized tracking system. The results indicated that according to full match outcome: winning status was characterized by players covering more total distance (p ≤ 0.05) and low-intensity running (<14.4 km·h) (p ≤ 0.05), whereas, losing status induced more sprinting (≥25.2 km·h) (p < 0.01) and high-intensity running (≥19.8 km·h) (p ≤ 0.05). However, according to partial match status (i.e., 15 minutes and half time), players covered more distance for all running intensities while winning (p < 0.01). Technical match performance scores were not influenced by match status. In conclusion, the present study showed that the physical activities including high-intensity running and total distance covered were related to the match status, whereas technical activities were not. The overall outcome shows that higher physical activity was associated with winning partial match periods. This approach highlights the importance of physical fitness in soccer and may help coaches to better modulate players' roles and team tactical organization throughout the match.

Prevalence of Dehydration Before Training Sessions, Friendly and Official Matches in Elite Female Soccer Players

PubMed Central

Castro-Sepulveda, Mauricio; Astudillo, Javier; Letelier, Pablo

2016-01-01

Abstract This study aimed to evaluate and compare the hydration states prior to different sporting events (training sessions, friendly and official matches) in elite female soccer players and relate that to the importance that the player attached to the hydration state as a determinant of sports performance. The hydration state of 17 female elite soccer players (age: 21.5 ± 3 years; body mass: 62 ± 6 kg; body height: 165 ± 9 cm) was determined by measuring their urine specific gravity (USG) prior to three different sports events: training sessions (PT), friendly (PF) and official (PO) matches. The importance that each player attached to the hydration state as a determinant of sports performance was evaluated through a simple questionnaire. An average of 47.05% of the soccer players were severely dehydrated (USG > 1.030), 33.33% were significantly dehydrated (USG > 1.020), 17.64% were mildly dehydrated (USG > 1.010) and 1.96% were euhydrated (USG < 1.010). The average USG was 1.027 ± 0.007 (PT = 1.029 ± 0.009; PF = 1.023 ± 0.010 and PO = 1.030 ± 0.006). Differences were found between urine specific gravity prior to a friendly and an official match (p = 0.03). No relationship was found between urine specific gravity and the importance each player attached to the hydration state as a determinant of sports performance. The results show that dehydration is the most prevalent hydration state of elite soccer players before training sessions, friendly and official matches. Players were most dehydrated prior to official matches, which was unlinked to the players’ perceived importance of hydration for sports performance. PMID:28149344

Executive Functioning in Highly Talented Soccer Players

PubMed Central

Verburgh, Lot; Scherder, Erik J. A.; van Lange, Paul A.M.; Oosterlaan, Jaap

2014-01-01

Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer. PMID:24632735

Return to Training and Playing After Acute Lisfranc Injuries in Elite Professional Soccer and Rugby Players.

PubMed

Deol, Rupinderbir Singh; Roche, Andrew; Calder, James D F

2016-01-01

Lisfranc joint injuries are increasingly recognized in elite soccer and rugby players. Currently, no evidence-based guidelines exist on time frames for return to training and competition after surgical treatment. To assess the time to return to training and playing after Lisfranc joint injuries. Case series; Level of evidence, 4. A consecutive series of 17 professional soccer and rugby players in the English Premier/Championship leagues was assessed using prospectively collected data. All were isolated injuries sustained during training or competitive matches. Each player had clinical and radiological evidence of an unstable Lisfranc injury and required surgical treatment. A standardized postoperative regimen was used. The minimum follow-up time was 2 years. Clinical and radiological follow-up was obtained in all 17 players. Seven players had primarily ligamentous injuries, and 10 had bony injuries. The time from injury to fixation ranged from 8 to 31 days, and hardware was removed at 16 weeks postoperatively. One athlete retired after a ligamentous injury; the remaining 16 players returned to training and full competition. Excluding the retired player, the mean time to return to training was 20.1 weeks (range, 18-24 weeks) and to full competition was 25.3 weeks (range, 21-31 weeks). There was a significant difference between the mean time to return to competition for rugby (27.8 weeks) and soccer players (24.1 weeks; P = .02) and for ligamentous (22.5 weeks) compared with bony injuries (26.9 weeks; P = .003). Three patients suffered deep peroneal nerve sensation loss, from which 1 patient did not fully recover. Return to competitive elite-level soccer and rugby is possible after surgically treated Lisfranc injuries. Return to training can take up to 24 weeks and return to playing up to 31 weeks, with bony injuries taking longer. © 2015 The Author(s).

Gender differences in match performance characteristics of soccer players competing in the UEFA Champions League.

PubMed

Bradley, Paul S; Dellal, Alexandre; Mohr, Magni; Castellano, Julen; Wilkie, Anna

2014-02-01

The aim of this study was to examine gender differences in match performance characteristics of elite soccer players. Fifty-four male and fifty-nine female soccer players were tracked during UEFA Champions League matches using a multi-camera system (Amisco, Nice, France). Male players covered more (P<.01) distance than female players in total during a match (Effect Size [ES]: 0.5) and at higher speed thresholds (>15, >18, 18-21, 21-23, 23-25 and >27kmh(-1); ES: 0.7-1.4). Decrements in the second versus first half (P<.01) were only evident in female players for the distance covered in total and at selected speed thresholds (12-15, >12 and >15kmh(-1); ES: 0.6). Male central midfielders covered more (P<.01) total distance during a match than female central midfielders and at selected speed thresholds (15-23kmh(-1); ES: 1.3-2.2). Male full-backs and wide midfielders covered a greater distance (P<.01) than female players in the same positions at higher speed thresholds (>15, 21-23, 23-25, 25-27 and >27kmh(-1); ES: 1.5-3.1). The distance covered during the most intense 5min period of the match (>15kmh(-1)) was higher (P<.01) in male compared to female players (ES: 1.0) but no distance deficit in the next versus the average 5min period was observed for either gender (ES: 0.1-0.2). No gender differences were found for technical events such as the number of ball touches, time in possession of the ball or total duels won during both halves and the entire match (ES: 0.1-0.3). However, female players lost the ball more often (P<.05) and displayed lower pass completion rates than male players during both halves and the entire match (ES: 0.5-0.9). The data demonstrate that large gender differences exist for match performance characteristics of players competing at the highest competitive standard of European soccer. Such detailed analyses could be useful for gender-specific training information for optimal preparation. However, more research is warranted to establish gender

Carbohydrates for Soccer: A Focus on Skilled Actions and Half-Time Practices

PubMed Central

Hills, Samuel P.; Russell, Mark

2017-01-01

Carbohydrate consumption is synonymous with soccer performance due to the established effects on endogenous energy store preservation, and physical capacity maintenance. For performance-enhancement purposes, exogenous energy consumption (in the form of drinks, bars, gels and snacks) is recommended on match-day; specifically, before and during match-play. Akin to the demands of soccer, limited opportunities exist to consume carbohydrates outside of scheduled breaks in competition, such as at half-time. The link between cognitive function and blood glucose availability suggests that carbohydrates may influence decision-making and technical proficiency (e.g., soccer skills). However, relatively few reviews have focused on technical, as opposed to physical, performance while also addressing the practicalities associated with carbohydrate consumption when limited in-play feeding opportunities exist. Transient physiological responses associated with reductions in activity prevalent in scheduled intra-match breaks (e.g., half-time) likely have important consequences for practitioners aiming to optimize match-day performance. Accordingly, this review evaluated novel developments in soccer literature regarding (1) the ergogenic properties of carbohydrates for skill performance; and (2) novel considerations concerning exogenous energy provision during half-time. Recommendations are made to modify half-time practices in an aim to enhance subsequent performance. Viable future research opportunities exist regarding a deeper insight into carbohydrate provision on match-day. PMID:29295583

Kinesiology tape mediates soccer-simulated and local peroneal fatigue in soccer players.

PubMed

Farquharson, Claire; Greig, Matt

2017-01-01

To investigate the efficacy of kinesiology taping in mediating the influence of fatigue on ankle sprain risk, 12 male soccer players completed single-leg dynamic balance trials pre- and post-exercise (soccer-specific protocol, isokinetic ankle inversion/eversion protocol) in each of three counter-balanced taping conditions (no tape, zinc oxide tape ZO, kinesiology tape KT). Balance was quantified as the overall stability index (OSI) and directional stability indices of platform deflection. Soccer-specific fatigue only increased OSI in the no tape condition (p = 0.03), with ZO and KT trials negating a fatigue affect. Localized fatigue increased OSI in the no tape (p = 0.01) and ZO (p = 0.05) trials, with no increase in the KT trial. A similar pattern was observed in medio-lateral and anterio-posterior balance indices. KT mediates soccer-simulated and local peroneal fatigue, with practical implications for epidemiological observations of increased injury risk during the latter stages of match play.

Hamstring Muscle Fatigue and Central Motor Output during a Simulated Soccer Match

PubMed Central

Marshall, Paul W. M.; Lovell, Ric; Jeppesen, Gitte K.; Andersen, Kristoffer; Siegler, Jason C.

2014-01-01

Purpose To examine changes in hamstring muscle fatigue and central motor output during a 90-minute simulated soccer match, and the concomitant changes in hamstring maximal torque and rate of torque development. Method Eight amateur male soccer players performed a 90-minute simulated soccer match, with measures performed at the start of and every 15-minutes during each half. Maximal torque (Nm) and rate of torque development (RTD; Nm.s–1) were calculated from maximal isometric knee flexor contractions performed at 10° of flexion. Hamstring peripheral fatigue was assessed from changes in the size and shape of the resting twitch (RT). Hamstring central motor output was quantified from voluntary activation (%) and normalized biceps femoris (BF) and medial hamstrings (MH) electromyographic amplitudes (EMG/M). Results Maximal torque was reduced at 45-minutes by 7.6±9.4% (p<0.05). RTD in time intervals of 0–25, 0–50, and 0–75 ms post-contraction onset were reduced after 15-minutes in the first-half between 29.6 to 46.2% (p<0.05), and were further reduced at the end of the second-half (p<0.05). Maximal EMG/M was reduced for biceps femoris only concomitant to the time-course of reductions in maximal torque (p = 0.007). The rate of EMG rise for BF and MH was reduced in early time periods (0–75 ms) post-contraction onset (p<0.05). No changes were observed for the size and shape of the RT, indicating no hamstring peripheral fatigue. Conclusion Centrally mediated reductions in maximal torque and rate of torque development provide insight into factors that may explain hamstring injury risk during soccer. Of particular interest were early reductions during the first-half of hamstring rate of torque development, and the decline in maximal EMG/M of biceps femoris in the latter stages of the half. These are important findings that may help explain why the hamstrings are particularly vulnerable to strain injury during soccer. PMID:25047547

Internal and External Match Loads of University-Level Soccer Players: A Comparison Between Methods.

PubMed

Sparks, Martinique; Coetzee, Ben; Gabbett, Tim J

2017-04-01

Sparks, M, Coetzee, B, and Gabbett, TJ. Internal and external match loads of university-level soccer players: a comparison between methods. J Strength Cond Res 31(4): 1072-7077, 2017-The aim of this study was to use individualized intensity zones to compare the external (velocity and player load, PL) and internal loads (heart rate, HR) of a cohort of university-level soccer players. Thirteen soccer players completed a 40-m maximum speed test and the Yo-Yo intermittent recovery test 1 (Yo-Yo IR1) to determine individualized velocity and HR thresholds. Heart rate values and global positioning system (GPS) data of each player were recorded during 5 league matches. A large (r = 0.46; p ≤ 0.01) correlation was found between time spent in the low-intensity (LI) velocity zone (LIVZ) and the LI HR zone. Similarly, there were moderate (r = 0.25; p ≤ 0.01) to large (r = 0.57; p ≤ 0.01) correlations between the relative and absolute time spent in the moderate-intensity (MI) velocity zone (MIVZ) and the MI HR zone. No significant correlations (p ≤ 0.01) existed between the high-intensity (HI) velocity zones (HIVZ) and the HI HR zone. On the other hand, PL showed significant correlations with all velocity and HR (absolute and relative) variables, with the exception of a nonsignificant correlation between the HI HR variables and PL. To conclude, PL showed good correlations with both velocity and HR zones and therefore may have the potential to serve as a good indicator of both external and internal soccer match loads.

Match-derived relative pitch area changes the physical and team tactical performance of elite soccer players in small-sided soccer games.

PubMed

Olthof, Sigrid B H; Frencken, Wouter G P; Lemmink, Koen A P M

2018-07-01

Small-sided games (SSGs) are used in training sessions to prepare for full-sized matches. For the same number of players, smaller pitch sizes result in decreased physical performance and shorter interpersonal distances. A relative pitch area derived from the full-sized match results in larger pitch sizes and this may increase the fit between SSGs and full-sized matches. This study aimed to investigate SSGs with a traditional small pitch and a match-derived relative pitch area in youth elite soccer players. Four age categories (under-13, under-15, under-17 and under-19) played 4 vs. 4 plus goalkeepers on a small (40x30m, 120m 2 relative pitch area) and large pitch (68x47m, 320m 2 relative pitch area). The number of games per age category ranged 15-30. Positional data (LPM-system) were collected to determine physical (total distance covered, high intensity distance and number of sprints) and team tactical (inter-team distance, LPW-ratio, surface area, stretch indices, goalkeeper-defender distance) performance measures and tactical variability. On a large pitch, physical performance significantly increased, inter-team and intra-team distances were significantly larger and tactical variability of intra-team distance measures significantly increased. The match-derived relative pitch area is an important training manipulation and leads to changes in physical and tactical performance 4 vs. 4 plus goalkeepers.

How Game Location Affects Soccer Performance: T-Pattern Analysis of Attack Actions in Home and Away Matches.

PubMed

Diana, Barbara; Zurloni, Valentino; Elia, Massimiliano; Cavalera, Cesare M; Jonsson, Gudberg K; Anguera, M Teresa

2017-01-01

The influence of game location on performance has been widely examined in sport contexts. Concerning soccer, game-location affects positively the secondary and tertiary level of performance; however, there are fewer evidences about its effect on game structure (primary level of performance). This study aimed to detect the effect of game location on a primary level of performance in soccer. In particular, the objective was to reveal the hidden structures underlying the attack actions, in both home and away matches played by a top club (Serie A 2012/2013-First Leg). The methodological approach was based on systematic observation, supported by digital recordings and T-pattern analysis. Data were analyzed with THEME 6.0 software. A quantitative analysis, with nonparametric Mann-Whitney test and descriptive statistics, was carried out to test the hypotheses. A qualitative analysis on complex patterns was performed to get in-depth information on the game structure. This study showed that game tactics were significantly different, with home matches characterized by a more structured and varied game than away matches. In particular, a higher number of different patterns, with a higher level of complexity and including more unique behaviors was detected in home matches than in the away ones. No significant differences were found in the number of events coded per game between the two conditions. THEME software, and the corresponding T-pattern detection algorithm, enhance research opportunities by going further than frequency-based analyses, making this method an effective tool in supporting sport performance analysis and training.

How Game Location Affects Soccer Performance: T-Pattern Analysis of Attack Actions in Home and Away Matches

PubMed Central

Diana, Barbara; Zurloni, Valentino; Elia, Massimiliano; Cavalera, Cesare M.; Jonsson, Gudberg K.; Anguera, M. Teresa

2017-01-01

The influence of game location on performance has been widely examined in sport contexts. Concerning soccer, game-location affects positively the secondary and tertiary level of performance; however, there are fewer evidences about its effect on game structure (primary level of performance). This study aimed to detect the effect of game location on a primary level of performance in soccer. In particular, the objective was to reveal the hidden structures underlying the attack actions, in both home and away matches played by a top club (Serie A 2012/2013—First Leg). The methodological approach was based on systematic observation, supported by digital recordings and T-pattern analysis. Data were analyzed with THEME 6.0 software. A quantitative analysis, with nonparametric Mann–Whitney test and descriptive statistics, was carried out to test the hypotheses. A qualitative analysis on complex patterns was performed to get in-depth information on the game structure. This study showed that game tactics were significantly different, with home matches characterized by a more structured and varied game than away matches. In particular, a higher number of different patterns, with a higher level of complexity and including more unique behaviors was detected in home matches than in the away ones. No significant differences were found in the number of events coded per game between the two conditions. THEME software, and the corresponding T-pattern detection algorithm, enhance research opportunities by going further than frequency-based analyses, making this method an effective tool in supporting sport performance analysis and training. PMID:28878712

Inter-individual Variability in Soccer Players of Different Age Groups Playing Different Positions

PubMed Central

Nikolaidis, Pantelis; Ziv, Gal; Lidor, Ronnie; Arnon, Michal

2014-01-01

The purpose of this study was twofold: (a) to profile physical characteristics and motor abilities of three age groups of soccer players – under 14 years, 14–17, and over 17, playing different positions – goalkeepers, defenders, midfielders, and forwards; and (b) to examine the inter-individual variability among the players in each age group in all physical and physiological measurements performed in the study. In addition, anthropometric, power, strength, and flexibility tests were administered. Findings showed large inter-individual variability in all three age groups and in all playing positions. Differences between playing positions were found only in the 14–17 group (body mass) and in the over-17 group (body height, body mass, fat-free mass, and mean power in the Wingate Anaerobic Test). Due to the observed large inter-individual variability, it was concluded that the findings obtained in the physical and physiological tests should be interpreted with caution when attempting to differentiate between successful and unsuccessful soccer players, as well as when trying to predict future success in soccer. PMID:25031689

Intensity and duration of intermittent exercise and recovery during a soccer match.

PubMed

Orendurff, Michael S; Walker, Jason D; Jovanovic, Mladen; Tulchin, Kirsten L; Levy, Morris; Hoffmann, David K

2010-10-01

Soccer is a sport consisting of high-intensity intermittent exercise, with players making forays across their anaerobic threshold for tactical advantage followed by periods of recovery. The intensity and duration of these work and recovery bouts were defined during a men's soccer match using StepWatch Activity Monitors recording step rate for each 3-second period. The data were coded by custom software to separate work bouts (step rate ≥ 4) from recovery bouts (step rate < 4), and a square wave of the pattern of bouts was plotted for 5 players: center forward, central midfielder, wing midfielder, central defender, and wing defender. Four values were calculated for each work and recovery bout identified: duration, and mean, maximum, and minimum step rate (intensity). This novel technique provided detailed graphical information on the duration and exercise intensity of each position throughout the match. The center midfielder was able to sustain work and recovery bout characteristics throughout the match and appeared to recover at higher intensity levels than other players. The forward showed the consequence of accumulated fatigue late in the match and was unable to sustain the duration of high-intensity work bouts observed earlier in the match. The central defender attenuated the intensity of his work and recovery bouts late in the match staying closer to a more moderate work rate with fewer high- or low-intensity bouts. Having objective data qualifying players' work and recovery bout characteristics might prove valuable for tactical decision making, substitution timing, and for planning future training sessions.

Anthropometric and Somatotype Characteristics of Young Soccer Players: Differences Among Categories, Subcategories, and Playing Position.

PubMed

Perroni, Fabrizio; Vetrano, Mario; Camolese, Giancarlo; Guidetti, Laura; Baldari, Carlo

2015-08-01

Considering that anthropometric parameters are important factors in the performance of the soccer players, the aim of this study was to explore the differences in anthropometric and somatotype characteristics of Italian young soccer players. Weight, height, body mass index, and somatotype of 112 young soccer players, grouped in Giovanissimi "A" (14 years), "B" (13 years), and "C" (12 years) as well as Allievi "B" (15 years) and "A" (16 years) and "Juniores" (older than 17 years), were evaluated. Statistical analysis tests were computed at p ≤ 0.05, and an analysis of variance for each somatotype was calculated to analyze the main effects and interactions of the factors: categories, subcategories, and playing position. Bonferroni's post hoc analysis was used to identify differences among mean values. Considering all subjects, we have found significant differences in categories, subcategories, and playing position between anthropometric values and a somatotype value of 2.8-3.8-2.9. Significant differences have found among goalkeepers and the others playing position in endomorphy (p ≤ 0.001) and with defenders and midfielders in ectomorphy (p < 0.01) components, whereas no differences in mesomorphy. Analyzing the interaction between subcategories and playing position factors, a significant effect was found only in the endomorphy component (p = 0.05). The analysis of anthropometric characteristic of Italian young soccer players indicates that players have high muscularity value and low adiposity. This study showed the presence of somatotype differences for playing position within categories also in the youngest categories and subcategories, in particular, in the endomorphy component. Young soccer players should be trained with more appropriate and specific training load to avoid the increased injury risk during adolescence.

"Soccer": The Beautiful Game

ERIC Educational Resources Information Center

Spires, Todd

2008-01-01

Soccer, or football as it is called in the rest of the world, is the most popular and fastest-growing global sport, with an estimated 240 million people regularly playing what Brazilian star Pele called "the beautiful game." Millions, worldwide, watch it on television. In 2006, the average viewership for each match of the month-long World Cup was…

Movement Patterns of a U-20 National Women's Soccer Team during Competitive Matches: Influence of Playing Position and Performance in the First Half.

PubMed

Ramos, Guilherme Passos; Nakamura, Fábio Yuzo; Pereira, Lucas Adriano; Junior, Wanderley Brilhante; Mahseredjian, Fábio; Wilke, Carolina Franco; Garcia, Emerson Silami; Coimbra, Cândido Celso

2017-09-01

The aim of this study was to determine the match locomotor characteristics of a sample of U-20 Brazilian female soccer players. Seven international matches were analyzed during the 2015 U-20 South American Championship, using global positioning technology. During a typical match, fullbacks and forwards covered greater distances in high-intensity running and sprinting than central defenders and midfielders (effect size [ES]=1.42-3.69). In the final 15 min of a game, total and high-intensity running distance and player load were ≈20 to 35% (ES=0.41-3.86) lower than in the first 15 min period for midfielders, fullbacks, forwards, and central defenders. Sprinting, and high-intensity running distances, and the frequency of accelerations >2 m . s -2 immediately after the most intense 5-min period declined in forwards (ES=1.78-2.67), fullbacks (ES=1.96-5.25), midfielders (ES=1.66-3.77), and central defenders (ES=1.50-4.22). Maintaining 'high' levels of activity in the first half resulted in ≈19% reductions in the second half for sprinting distance and frequency of accelerations >2 m . s -2 (ES=0.43 and 0.88), while increases in these locomotor activities were observed in situations with 'low' levels of activity (ES=0.64 and 1.12, for sprinting and accelerations >2 m . s -2 , respectively) (within-subject analysis). The data demonstrate that high-intensity efforts are reduced during various phases of international matches and overall activity patterns vary among playing positions. This information could be useful in the development and prescription of sex- and age-specific training regimes. © Georg Thieme Verlag KG Stuttgart · New York.

Heart Rate and Motion Analysis by GPS in Beach Soccer

PubMed Central

Castellano, Julen; Casamichana, David

2010-01-01

Although beach soccer has become increasingly popular in recent years very little scientific research has been conducted into the sport. A pilot study was carried out with the aim of examining the physiological (heart rate) and physical (motion analysis) responses of beach soccer players during competitive matches. Ten players (age 25.5 ± 0.5 years; height 1.80 ± 0.08 m; weight 78.2 ± 5.6 kg.) were studied over five beach soccer matches. The physiological demands were analysed by measuring heart rate (HR) using telemetric devices, while the physical profile was evaluated by recording motion and speed by means of GPS devices. During competitive matches, players obtained a HRmean of 165.2 bpm (86.5% HRmax), with 59.3% of the time participating (TP) corresponding to values above 90% of the HRmax. The distance covered per minute of participation was 97.7 m, with 9.5% of this distance corresponding to high-intensity running and 2.5% to sprint; the work:rest ratio was 1.4:1 and the maximum speed 21.7 km·h-1. These results showed that beach soccer is an intermittent physical activity of greater intensity than other team games. It requires a major contribution from the anaerobic system as emphasis is placed on players making quick bursts of high-intensity activity separated by brief rest periods. Key points The distance covered per minute of play is around 100 m. Beach soccer is an intermittent sport with a work:rest ratio of 1.4:1. The playing surface in beach soccer is an important handicap to obtain maximum speeds. Beach soccer has a high physiological intensity, with more than half of the game is spent at intensities above 90 % of the HRmax. PMID:24149392

Current Approaches to Tactical Performance Analyses in Soccer Using Position Data.

PubMed

Memmert, Daniel; Lemmink, Koen A P M; Sampaio, Jaime

2017-01-01

Tactical match performance depends on the quality of actions of individual players or teams in space and time during match-play in order to be successful. Technological innovations have led to new possibilities to capture accurate spatio-temporal information of all players and unravel the dynamics and complexity of soccer matches. The main aim of this article is to give an overview of the current state of development of the analysis of position data in soccer. Based on the same single set of position data of a high-level 11 versus 11 match (Bayern Munich against FC Barcelona) three different promising approaches from the perspective of dynamic systems and neural networks will be presented: Tactical performance analysis revealed inter-player coordination, inter-team and inter-line coordination before critical events, as well as team-team interaction and compactness coefficients. This could lead to a multi-disciplinary discussion on match analyses in sport science and new avenues for theoretical and practical implications in soccer.

Groin Problems in Male Soccer Players Are More Common Than Previously Reported.

PubMed

Harøy, Joar; Clarsen, Ben; Thorborg, Kristian; Hölmich, Per; Bahr, Roald; Andersen, Thor Einar

2017-05-01

The majority of surveillance studies in soccer have used a time-loss injury definition, and many groin problems result from overuse, leading to gradually increasing pain and/or reduced performance without necessarily causing an absence from soccer training or match play. Thus, the magnitude of groin problems in soccer has probably been underestimated in previous studies based on traditional injury surveillance methods. To investigate the prevalence of groin problems among soccer players of both sexes and among male soccer players at different levels of play through a new surveillance method developed to capture acute and overuse problems. Descriptive epidemiology study. We registered groin problems during a 6-week period of match congestion using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A total of 240 players from 15 teams across different levels of play and from both sexes were included, and they responded to the weekly questionnaire. We calculated the average weekly prevalence of all groin problems and substantial groin problems. Of the 240 players, 112 male players (59%) and 20 female players (45%) reported at least 1 episode of groin problems. The average weekly prevalence of any groin problem and substantial groin problem for all male players was 29% (range, 23%-32% across different levels) and 10% (7%-13%), respectively. Elite male players had an increased risk of experiencing groin problems (odds ratio: 3.1, 95% CI: 1.5-6.4, P = .03) compared with elite female players. There was no difference in the risk of experiencing groin problems among elite, subelite, and amateur male players. For substantial problems, there was no difference between elite male and elite female players or among levels of play for senior male soccer players. We found a high prevalence of groin problems among male soccer players during a period with match congestion. Time-loss definition as used in previous injury surveillance studies captured only one

Comparing the physical demands of friendly matches and small-sided games in semiprofessional soccer players.

PubMed

Casamichana, David; Castellano, Julen; Castagna, Carlo

2012-03-01

This study compared the physical demands of friendly matches (FMs) and small-sided games (SGs) in semiprofessional soccer players by means of global positioning system technology. Twenty-seven semiprofessional soccer players were monitored during 7 FMs and 9 sessions involving different SGs. Their physical profile was described on the basis of 20 variables related to distances and frequencies at different running speeds, the number of accelerations, and through global indicators of workload such as the work:rest ratio, player workload, and the exertion index. Results showed significant differences (p < 0.01) between SGs and FMs for the following variables: overall workload (SG > FM); the distribution of the distance covered in the speed zones 7.0-12.9 km·h(-1) (SG > FM) and >21 km·h(-1) (FM > SG); the distribution of time spent in certain speed zones (FM > SG: 0.0-6.9 and >21 km·h(-1); FM > SG: 7.0-12.9 km·h(-1)). More sprints per hour of play were performed during FMs, with greater mean durations and distances, greater maximum durations and distances, and a greater frequency per hour of play for sprints of 10-40 and >40 m (p < 0.01). The frequency of repeated high-intensity efforts was higher during FM (p < 0.01). The results show that coaches and strength and conditioning professionals should consider FMs during their training routine to foster specific adaptations in the domain of high-intensity effort.

Mortality on match days of the German national soccer team: a time series analysis from 1995 to 2009.

PubMed

Medenwald, D; Kuss, O

2014-09-01

There is inconsistent evidence on population mortality, especially cardiovascular disease mortality, on match days of national soccer teams during particular international tournaments. This study examines the number of deaths in Germany on match days of the national soccer team during a long-term period including several tournaments. We analysed all registered daily deaths in Germany from 1995 to 2009 (11 225 966 cases) using time series analysis methods. Following the Box/Jenkins approach, we applied a seasonal autoregressive integrated moving average model. To assess the effect of match days, we performed an intervention analysis by including a transfer function model representing match days of the national team in the statistical analyses. We conducted separate analyses for all matches and for matches during international tournaments (European and World Championships) only. Time series and results were stratified in terms of sex, age (<50 years, 50-70 years, >70 years) and cause of death (cardiovascular deaths, injuries, others). We performed a further independent analysis focusing only on the effect of match results (victory, loss, draw) and kind of tournament (international championships, qualifications, friendly matches). Most of the results did not indicate a distinct effect of matches of the national team on general mortality. Moreover, all null value deviations were small when compared with the average number of daily deaths (n=2270). There is no relevant increase or decrease in mortality on match days of the German national soccer team. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Physical and technical performances are not associated with tactical prominence in U14 soccer matches.

PubMed

Clemente, Filipe Manuel; Figueiredo, António José; Martins, Fernando Manuel Lourenço; Mendes, Rui Sousa; Wong, Del P

2016-01-01

The aim of this study was to analyse the association between physical/technical variables and the tactical prominence variables in U14 soccer matches. Twenty-two young amateur soccer players (13.5 [Formula: see text] 0.5 years old, 5.4 [Formula: see text] 0.5 years of practice, 163.3 [Formula: see text] 9.8 cm in body height) from two teams of the Portuguese regional league volunteered for the study. Our results showed positive and moderate correlation between dribbling test and betweenness centrality (r = 0.324; p = 0.142), and negative moderate correlation between %fatigue index and betweenness centrality (r = -0.390; p = 0.073). Physical and technical variables had no statistical differences among tactical positions. Nevertheless, when tactical prominence of players from four tactical positions were compared, significant differences were found in terms of degree prestige (p = 0.001) and degree centrality (p = 0.002). This pilot study did not find strong correlations between physical/technical levels and tactical prominence in soccer matches.

Attacking and defensive styles of play in soccer: analysis of Spanish and English elite teams.

PubMed

Fernandez-Navarro, Javier; Fradua, Luis; Zubillaga, Asier; Ford, Paul R; McRobert, Allistair P

2016-12-01

The aim of this study was to define and categorise different styles of play in elite soccer and associated performance indicators by using factor analysis. Furthermore, the observed teams were categorised using all factor scores. Data were collected from 97 matches from the Spanish La Liga and the English Premier League from the seasons 2006-2007 and 2010-2011 using the Amisco® system. A total of 19 performance indicators, 14 describing aspects of attacking play and five describing aspects of defensive play, were included in the factor analysis. Six factors, representing 12 different styles of play (eight attacking and four defensive), had eigenvalues greater than 1 and explained 87.54% of the total variance. Direct and possession styles of play, defined by factor 1, were the most apparent styles. Factor analysis used the performance indicators to cluster each team's style of play. Findings showed that a team's style of play was defined by specific performance indicators and, consequently, teams can be classified to create a playing style profile. For practical implications, playing styles profiling can be used to compare different teams and prepare for opponents in competition. Moreover, teams could use specific training drills directed to improve their styles of play.

Effects of a Carbohydrate-Electrolyte Drink on Specific Soccer Tests and Performance

PubMed Central

Ostojic, Sergej M.; Mazic, Sanja

2002-01-01

The aim of this study was to examine the effects of a carbohydrate-electrolyte drink on specific soccer tests and performance. Twenty-two professional male soccer players volunteered to participate in the study. The players were allocated to two assigned trials ingesting carbohydrate-electrolyte drink (7% carbohydrates, sodium 24 mmol.l-1, chloride 12 mmol.l-1, potassium 3 mmol.l-1) or placebo during a 90 min on-field soccer match. The trials were matched for subjects’ age, weight, height and maximal oxygen uptake. Immediately after the match, players completed four soccer-specific skill tests. Blood glucose concentration [mean (SD)] was higher at the end of the match-play in the carbohydrate-electrolyte trial than in the placebo trial (4.4 (0.3) vs. 4.0 (0.3) mmol.l-1, P < 0.05). Subjects in the carbohydrate-electrolyte trial finished the specific dribble test faster in comparison with subjects in the placebo trial (12.9 (0.4) vs. 13.6 (0.5) s, P < 0.05). Ratings of the precision test were higher in the carbohydrate-electrolyte trial as compared to the placebo trial (17.2 (4.8) vs. 15.1 (5.2), P < 0.05) but there were no differences in coordination test and power test results between trials. The main finding of the present study indicates that supplementation with carbohydrate-electrolyte solution improved soccer-specific skill performance and recovery after an on-field soccer match compared with ingestion of placebo. This suggests that soccer players should consume carbohydrate-electrolyte fluid throughout a game to help prevent deterioration in specific skill performance. PMID:24688270

Polar Coordinate Analysis of Relationships With Teammates, Areas of the Pitch, and Dynamic Play in Soccer: A Study of Xabi Alonso

PubMed Central

Maneiro Dios, Rubén; Amatria Jiménez, Mario

2018-01-01

Research in soccer has traditionally focused on very specific aspects of the game, such as technical and physiological aspects, and has largely ignored important issues such as tactical performance and the role of individual players within the team. The aim of this study was to study the different relationships that Xabi Alonso, one of the world's best midfielders, establishes with his teammates during offensive play, and to investigate his connections with the pitch in terms of where his direct interventions started and finished, his use of technical actions, his involvement in set plays and interceptions, and his relationship with shots at goal. To do this, we analyzed all the matches played by the winner of the 2012 UEFA European Championship: Spain. We employed an observational methodology design (Anguera, 1979) using a modified version of the ad hoc soccer observation instrument designed by Amatria et al. (2016). The resulting data were analyzed by polar coordinate analysis (Gorospe and Anguera, 2000), which is a powerful data reduction technique with high predictive power. The results showed significant associations (Z > 1.96; p < 0.05) between Alonso and players in different positions, a wide sphere of influence on the pitch, both for the start and end of interventions, and a strong link with game interruptions and interceptions and with the use of different technical actions. No significant associations were detected for type of shot. Studies on tactical performance that take account of the multiple factors involved in soccer will lead to better decision-making by coaches and facilitate analysis of a player's true performance. PMID:29628905

Evaluation of the Match External Load in Soccer: Methods Comparison.

PubMed

Castagna, Carlo; Varley, Matthew; Póvoas, Susana C A; D'Ottavio, Stefano

2017-04-01

To test the interchangeability of 2 match-analysis approaches for external-load detection considering arbitrary selected speeds and metabolic power (MP) thresholds in male top-level soccer. Data analyses were performed considering match physical performance of 60 matches (1200 player cases) of randomly selected Spanish, German, and English first-division championship matches (2013-14 season). Match analysis was performed with a validated semiautomated multicamera system operating at 25 Hz. During a match, players covered 10,673 ± 348 m, of which 1778 ± 208 m and 2759 ± 241 m were performed at high intensity, as measured using speed (≥16 km/h, HI) and metabolic power (≥20 W/kg, MPHI) notations. High-intensity notations were nearly perfectly associated (r = .93, P < .0001). A huge method bias (980.63 ± 87.82 m, d = 11.67) was found when considering MPHI and HI. Very large correlations were found between match total distance covered and MPHI (r = .84, P < .0001) and HI (r = .74, P < .0001). Player high-intensity decelerations (≥-2 m/s 2 ) were very largely associated with MPHI (r = .73, P < .0001). The speed and MP methods are highly interchangeable at relative level (magnitude rank) but not absolute level (measure magnitude). The 2 physical match-analysis methods can be independently used to track match external load in elite-level players. However, match-analyst decisions must be based on use of a single method to avoid bias in external-load determination.

Coalitional Physical Competition : Acute Salivary Steroid Hormone Responses among Juvenile Male Soccer Players in Hong Kong.

PubMed

McHale, Timothy S; Chee, Wai-Chi; Chan, Ka-Chun; Zava, David T; Gray, Peter B

2018-06-16

A large body of research links testosterone and cortisol to male-male competition. Yet, little work has explored acute steroid hormone responses to coalitional, physical competition during middle childhood. Here, we investigate testosterone, dehydroepiandrosterone (DHEA), androstenedione, and cortisol release among ethnically Chinese boys in Hong Kong (N = 102), aged 8-11 years, during a soccer match (n = 84) and an intrasquad soccer scrimmage (n = 81), with 63 participants competing in both treatments. The soccer match and intrasquad soccer scrimmage represented out-group and in-group treatments, respectively. Results revealed that testosterone showed no measurable change. DHEA increased during both treatments in the majority of participants and the degree of change had no relation to independent variables (e.g., performance, age, treatment, outcome) or covariate measures (Body Mass Index, Pubertal Development Scale). Most boys experienced androstenedione increases during match play, but no significant differences during the intrasquad soccer scrimmage competitions. The magnitude of change differed significantly between treatments and was positively associated with age. These latter findings suggest boys' androstenedione responses may be sensitive to competitor type (i.e., unknown competitors vs. peers). For most subjects, cortisol significantly increased during match play, decreased during the intrasquad soccer scrimmage, and differed significantly between treatments, suggesting each treatment promoted a different psychological state among competitors. Cortisol/DHEA molar ratio decreased during the intrasquad scrimmage, suggestive of a more relaxed mental state. These data shed new light on potential proximate mechanisms associated with coalitional competition among prepubescent boys, with relevance to adrenarche and life history theory.

Nutritional Status and Daytime Pattern of Protein Intake on Match, Post-Match, Rest and Training Days in Senior Professional and Youth Elite Soccer Players.

PubMed

Bettonviel A, E O; Brinkmans N, Y J; Russcher, Kris; Wardenaar, Floris C; Witard, Oliver C

2016-06-01

The nutritional status of elite soccer players across match, postmatch, training and rest days has not been defined. Recent evidence suggests the pattern of dietary protein intake impacts the daytime turnover of muscle proteins and, as such, influences muscle recovery. We assessed the nutritional status and daytime pattern of protein intake in senior professional and elite youth soccer players and compared findings against published recommendations. Fourteen senior professional (SP) and 15 youth elite (YP) soccer players from the Dutch premier division completed nutritional assessments using a 24-hr web-based recall method. Recall days consisted of a match, postmatch, rest, and training day. Daily energy intake over the 4-day period was similar between SP (2988 ± 583 kcal/day) and YP (2938 ± 465 kcal/day; p = .800). Carbohydrate intake over the combined 4-day period was lower in SP (4.7 ± 0.7 g·kg-1 BM·day-1) vs. YP (6.0 ± 1.5 g·kg-1 BM·day-1, p = .006) and SP failed to meet recommended carbohydrate intakes on match and training days. Conversely, recommended protein intakes were met for SP (1.9 ± 0.3 g·kg-1 BM·day-1) and YP (1.7 ± 0.4 g·kg-1 BM·day-1), with no differences between groups (p = .286). Accordingly, both groups met or exceeded recommended daily protein intakes on individual match, postmatch, rest and training days. A similar "balanced" daytime pattern of protein intake was observed in SP and YP. To conclude, SP increased protein intake on match and training days to a greater extent than YP, however at the expense of carbohydrate intake. The daytime distribution of protein intake for YP and SP aligned with current recommendations of a balanced protein meal pattern.

Practice and play as determinants of self-determined motivation in youth soccer players.

PubMed

Hendry, David T; Crocker, Peter R E; Hodges, Nicola J

2014-01-01

Based upon predictions derived from the Developmental Model of Sports Participation, we tested whether hours in domain-specific play (self-led activities) and practice (coach-led activities) during childhood (~5-12 year) in an elite group of youth soccer players from the UK (N = 144) were related to motivation. Independent analysis of three different age groups (Under 13, 15 and 17 year) did not show relations between play and practice activities during childhood and global measures of motivation. However, secondary analysis showed that when controlling for years in soccer, years in the UK Academy system were negatively related to global indices of self-determined motivation (SDI) and positively related to controlled motivation for the oldest players. Despite predictions, there was no evidence that play during childhood was positively related to more SDI. Prospective research is recommended to enable more robust conclusions about the role of early developmental practice activities, especially early specialisation in a high-performance system, on both skill and psychosocial development.

Effects of carbohydrate-hydration strategies on glucose metabolism, sprint performance and hydration during a soccer match simulation in recreational players.

PubMed

Kingsley, Michael; Penas-Ruiz, Carlos; Terry, Chris; Russell, Mark

2014-03-01

This study compared the effects of three carbohydrate-hydration strategies on blood glucose concentration, exercise performance and hydration status throughout simulated soccer match-play. A randomized, double-blind and cross-over study design was employed. After familiarization, 14 recreational soccer players completed the soccer match simulation on three separate occasions. Participants consumed equal volumes of 9.6% carbohydrate-caffeine-electrolyte (∼ 6 mg/kg BW caffeine) solution with carbohydrate-electrolyte gels (H-CHO), 5.6% carbohydrate-electrolyte solution with electrolyte gels (CHO) or electrolyte solution and electrolyte gels (PL). Blood samples were taken at rest, immediately before exercise and every 15 min during exercise (first half: 15, 30, 45 min; second half: 60, 75, 90 min). Supplementation influenced blood glucose concentration (time × treatment interaction: p<0.001); however, none of the supplementation regimes were effective in preventing a drop in blood glucose at 60 min. Mean sprint speed was 3 ± 1% faster in H-CHO when compared with PL (treatment: p=0.047). Supplementation caused a 2.3 ± 0.5% increase in plasma osmolality in H-CHO (p<0.001) without change in CHO or PL. Similarly, mean sodium concentrations were 2.1 ± 0.4% higher in H-CHO when compared with PL (p=0.006). Combining high carbohydrate availability with caffeine resulted in improved sprint performance and elevated blood glucose concentrations throughout the first half and at 90 min of exercise; however, this supplementation strategy negatively influenced hydration status when compared with 5.6% carbohydrate-electrolyte and electrolyte solutions. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Determination of the effects of playing soccer on physical fitness in individuals with transtibial amputation.

PubMed

Guchan, Zehra; Bayramlar, Kezban; Ergun, Nevin

2017-06-01

The aim of this paper is to determine the effects of playing soccer on various components of physical performance such as body composition, muscular endurance, anaerobic power, flexibility, balance, and speed of individuals with transtibial amputation. Twelve amputee football players aged 26.67±7.76 years and twelve sedentary individuals aged 33±6.7 years were involved in this study. Body composition, and isotonic and isometric endurance of trunk muscles were assessed. Vertical jump test, sit-and-reach test, modified Thomas test, Berg Balance Scale, L test, and figure-of-eight walk (F8W) test were used to assess other physical fitness parameters. The Body Mass Index, waist circumference and body fat percentages of the amputee soccer players were significantly lower than the sedentary amputees (P<0.05). The endurance of back extensors was significantly higher in the soccer group (119.33±47.15 s) than the endurance in the control group (26.25±15.96 s) (P<0.001). Subjects belonging to the soccer group had significantly higher anaerobic power than those in the control group (P<0.05). Flexibility, as assessed by the sit-and-reach test was significantly higher for the soccer group (P=0.002), whereas the modified Thomas test, which is also used to measure flexibility, indicated no significant difference among both groups (P>0.05). Balance was higher in the soccer group (P=0.023). The completion period of the F8W test was significantly lower in the soccer group (4.54±0.9 s) than in the control group (7.71±2.25 s) (P<0.001). No significant difference was observed in the numbers of steps measured during the F8W test (P=0.231). This is the first study which investigates the effects of sports on the physical fitness of individuals with transtibial amputation with the inclusion of a control group. Overall findings present the benefits of participating in playing soccer on physical fitness parameters of amputees, but further studies with randomized controlled trials, with

Effects of age, maturity and body dimensions on match running performance in highly trained under-15 soccer players.

PubMed

Buchheit, Martin; Mendez-Villanueva, Alberto

2014-01-01

The aim of the present study was to compare, in 36 highly trained under-15 soccer players, the respective effects of age, maturity and body dimensions on match running performance. Maximal sprinting (MSS) and aerobic speeds were estimated. Match running performance was analysed with GPS (GPSport, 1 Hz) during 19 international friendly games (n = 115 player-files). Total distance and distance covered >16 km h(-1) (D > 16 km h(-1)) were collected. Players advanced in age and/or maturation, or having larger body dimensions presented greater locomotor (Cohen's d for MSS: 0.5-1.0, likely to almost certain) and match running performances (D > 16 km h(-1): 0.2-0.5, possibly to likely) than their younger, less mature and/or smaller teammates. These age-, maturation- and body size-related differences were of larger magnitude for field test measures versus match running performance. Compared with age and body size (unclear to likely), maturation (likely to almost certainly for all match variables) had the greatest impact on match running performance. The magnitude of the relationships between age, maturation and body dimensions and match running performance were position-dependent. Within a single age-group in the present player sample, maturation had a substantial impact on match running performance, especially in attacking players. Coaches may need to consider players' maturity status when assessing their on-field playing performance.

Injuries in youth amateur soccer and rugby players--comparison of incidence and characteristics.

PubMed

Junge, A; Cheung, K; Edwards, T; Dvorak, J

2004-04-01

In reviewing the literature on sports injuries, few studies could be found in which exposure related incidences of injury in different types of sport were compared. These studies indicated that ice hockey, handball, basketball, soccer, and rugby are popular team sports with a relatively high risk of injury. The aim of the study was to compare the characteristics and incidence of injuries in male youth amateur soccer and rugby players. This prospective cohort study comprised an initial baseline examination to ascertain the characteristics of the players and their level of performance, and a one season observation period during which a physician visited the team weekly and documented all occurring injuries. Twelve soccer and 10 rugby school teams with male amateur players aged 14-18 years were selected for the study. 145 soccer and 123 rugby players could be followed up over one season. Comparison of the incidence of soccer and rugby injuries indicated that rugby union football was associated with a significantly higher rate of injury than soccer. The differences were pronounced for contact injuries, injuries of the head, neck, shoulder, and upper extremity, as well as for concussion, fractures, dislocations, and strains. Rugby players incurred 1.5 times more overuse and training injuries in relation to exposure time, and 2.7 times more match injuries than soccer players. Three rugby players but no soccer players had to stop their participation in sport because of severe injury. The incidence of injury in New Zealand school teams playing soccer or rugby union is high, probably in part because of the low ratio of hours spent in training relative to hours spent playing matches. The development and implementation of preventive interventions to reduce the rate and severity of injury is recommended.

Injuries in youth amateur soccer and rugby players—comparison of incidence and characteristics

PubMed Central

Junge, A; Cheung, K; Edwards, T; Dvorak, J

2004-01-01

Objectives: In reviewing the literature on sports injuries, few studies could be found in which exposure related incidences of injury in different types of sport were compared. These studies indicated that ice hockey, handball, basketball, soccer, and rugby are popular team sports with a relatively high risk of injury. The aim of the study was to compare the characteristics and incidence of injuries in male youth amateur soccer and rugby players. Methods: This prospective cohort study comprised an initial baseline examination to ascertain the characteristics of the players and their level of performance, and a one season observation period during which a physician visited the team weekly and documented all occurring injuries. Twelve soccer and 10 rugby school teams with male amateur players aged 14–18 years were selected for the study. 145 soccer and 123 rugby players could be followed up over one season. Results: Comparison of the incidence of soccer and rugby injuries indicated that rugby union football was associated with a significantly higher rate of injury than soccer. The differences were pronounced for contact injuries, injuries of the head, neck, shoulder, and upper extremity, as well as for concussion, fractures, dislocations, and strains. Rugby players incurred 1.5 times more overuse and training injuries in relation to exposure time, and 2.7 times more match injuries than soccer players. Three rugby players but no soccer players had to stop their participation in sport because of severe injury. Conclusion: The incidence of injury in New Zealand school teams playing soccer or rugby union is high, probably in part because of the low ratio of hours spent in training relative to hours spent playing matches. The development and implementation of preventive interventions to reduce the rate and severity of injury is recommended. PMID:15039253

Injuries in Professional Male Soccer Players in the Netherlands: A Prospective Cohort Study

PubMed Central

Stubbe, Janine H.; van Beijsterveldt, Anne-Marie M. C.; van der Knaap, Sissi; Stege, Jasper; Verhagen, Evert A.; van Mechelen, Willem; Backx, Frank J. G.

2015-01-01

Context: Injuries are a major adverse event in a soccer player's career. Reducing injury incidence requires a thorough knowledge of the epidemiology of soccer injuries. Objective: To investigate the incidence and characteristics of injuries in the Dutch premier soccer league. Design: Cohort study. Setting: The Dutch premier soccer league. Patients or Other Participants: During the 2009–2010 soccer season, a total of 217 professional soccer players from 8 teams were prospectively followed. Main Outcome Measure(s): The medical staff recorded time-loss injuries, including information on injuries (ie, type, body part, duration) and exposure data for training sessions and matches. Results: A total of 286 injuries were recorded, affecting 62.7% of the players. The overall injury incidence was 6.2 injuries per 1000 player-hours, 2.8 in training sessions and 32.8 in matches. Most of the recorded injuries were acute (68.5%). Eight percent of the injuries were classified as recurrent. Injuries were most likely to be located in the lower extremities (82.9%). Injury time loss ranged from 1 to 752 days, with a median of 8 days. Knee injuries had the greatest consequences in terms of days of absence from soccer play (on average, 45 days). The most common diagnosis was muscle/tendon injury of the lower extremities (32.9%). Conclusions: Injury risk in the Dutch premier soccer league is high, especially during matches. Preventive measures should focus on the most common diagnoses, namely, muscle/tendon injuries of the lower extremities. PMID:25531144

Headache and soccer: a survey in professional soccer players of the Italian "Serie A".

PubMed

Mainardi, Federico; Alicicco, Ernesto; Maggioni, Ferdinando; Devetag, Flavio; Lisotto, Carlo; Zanchin, Giorgio

2009-02-01

The aim of the study was to assess the occurrence and the clinical features of primary headaches in a sample of players of the Italian Soccer League first division. The design of the study allowed a retrospective and prospective diagnosis of primary headaches according to the International Classification of Headache Disorders-II edition (ICHD-II), using anonymous questionnaires, which had to be filled out at regular times during the playing season. A total of 83 athletes playing in four different clubs were involved; four of them changed football team during the season and so did not complete the study. During the championship three soccer players reported headache (3.6%) with features fulfilling ICHD-II criteria for episodic tension-type headache. Important and prolonged physical effort was reported as aggravating factor in one case, but no attacks occurred during competitive matches. The same athletes had reported a personal history of episodic tension-type headache. In conclusion, the occurrence of primary headaches among professional soccer players of Italian first division championship appear to be strikingly lower, as compared to that found in the general population. A possible explanation could be given by the selection operated by a career which is not compatible with unpredictable, disabling attacks.

Movement analysis of Australian national league soccer players using global positioning system technology.

PubMed

Wehbe, George M; Hartwig, Timothy B; Duncan, Craig S

2014-03-01

Player activity profiles of match play provide valuable information for optimal athlete training prescriptions, competition strategies, and managing load and recovery and are currently lacking in elite Australian-league (A-League) soccer. The aims of the study were, therefore, to (a) determine match activity profiles for elite A-League soccer players and make match-half and positional comparisons and (b) examine the effect of situational factors including evolving match status (drawing, winning, or losing) and goals being scored and conceded on selected match activity profile variables. Global positioning system tracking devices were used to determine activity profiles of 19 elite male adult soccer players during 8 preseason matches (n = 95 files). Total distance, average speed, high-intensity running (HIR) distance, and very high-intensity running distance decreased from the first to the second half by 7.92, 9.47, 10.10, and 10.99%, respectively. Midfielders covered 11.69% more total distance, 28.08% more HIR distance, and had a 10.93% higher average speed than defenders (p ≤ 0.05; d = 1.90, 1.03, and 1.83, respectively). Attackers performed 27.50 and 30.24% less medium accelerations than defenders and midfielders, respectively (p < 0.01; d = 1.54, and 1.73). When the team was winning, average speed was 4.17% lower than when the team was drawing (p ≤ 0.05, d = 0.32). Scoring or conceding goals did not appear to affect HIR. This study adds to limited knowledge of match demands in elite A-League soccer. The match activity profiles provide descriptive benchmarks that could be used to make comparisons with other elite level soccer populations while also providing a framework for game-specific training prescription, competition strategy, and load management. The generalization that defenders experience a relatively lower match load may be questionable given their relatively high acceleration and deceleration demands.

Soccer-Specific Fatigue and Eccentric Hamstrings Muscle Strength

PubMed Central

Greig, Matt; Siegler, Jason C

2009-01-01

Context: Epidemiologic findings of higher incidences of hamstrings muscle strains during the latter stages of soccer match play have been attributed to fatigue. Objective: To investigate the influence of soccer-specific fatigue on the peak eccentric torque of the knee flexor muscles. Design: Descriptive laboratory study. Setting: Controlled laboratory environment. Patients or Other Participants: Ten male professional soccer players (age  =  24.7 ± 4.4 years, mass  =  77.1 ± 8.3 kg, V̇o2max  =  63.0 ± 4.8 mL·kg−1·min−1). Intervention(s): Participants completed an intermittent treadmill protocol replicating the activity profile of soccer match play, with a passive halftime interval. Before exercise and at 15-minute intervals, each player completed isokinetic dynamometer trials. Main Outcome Measure(s): Peak eccentric knee flexor torque was quantified at isokinetic speeds of 180° · s−1, 300° · s−1, and 60° · s−1, with 5 repetitions at each speed. Results: Peak eccentric knee flexor torque at the end of the game (T300eccH105  =  127 ± 25 Nm) and at the end of the passive halftime interval (T300eccH60  =  133 ± 32 Nm) was reduced relative to T300eccH00 (167 ± 35 Nm, P < .01) and T300eccH15 (161 ± 35 Nm, P  =  .02). Conclusions: Eccentric hamstrings strength decreased as a function of time and after the halftime interval. This finding indicates a greater risk of injuries at these specific times, especially for explosive movements, in accordance with epidemiologic observations. Incorporating eccentric knee flexor exercises into resistance training sessions that follow soccer-specific conditioning is warranted to try to reduce the incidence or recurrence of hamstrings strains. PMID:19295963

Are physical performance and injury risk in a professional soccer team in match-play affected over a prolonged period of fixture congestion?

PubMed

Carling, C; Le Gall, F; Dupont, G

2012-01-01

In this study, the effects of a prolonged period of fixture congestion (8 successive official matches in 26 days) on physical performance and injury risk and severity in a professional soccer team were investigated. Computerised motion-analysis was used to analyse the overall distance covered and that run at light- (0.0-11.0 km·h - 1); low- (11.1-14.0 km·h - 1); moderate- (14.1-19.7 km·h - 1) and high-intensities (≥19.8 km·h - 1) for the team as a whole. Distances were measured in metres per minute. Information on match injuries was recorded prospectively. The overall distance covered varied across successive matches (p<0.001) as more distance was run in games 4 and 7 compared to 2 and 3, respectively (126.6 ± 12.3 m·min - 1 and 125.0 ± 13.2 m·min - 1 vs. 116.0 ± 8.0 m·min - 1 and 115.5 ± 11.0 m·min - 1). Distance run in light-intensity exercise also varied (p<0.001) as more distance was covered in game 4 vs. 1, 2, 3, 5 and 6 (75.5 ± 3.8 m·min - 1 vs. 70.6 ± 2.4 m·min - 1, 71.8 ± 3.4 m·min - 1, 69.3 ± 2.6 m·min - 1, 71.5 ± 3.1 m·min - 1, and 70.3 ± 2.8 m·min - 1) and in game 8 vs. game 3 (73.1 ± 3.8 vs. 69.3 ± 2.6 m·min - 1), respectively. When comparing match halves, there were no differences across games in overall or high-intensity distance covered and performance in these measures was similar for matches played before, during and after this period. Globally, no difference over the 8 games combined was observed between the reference team and opponents in any of the performance measures whereas the overall distance covered and that in low- (both p<0.001) and high-intensity running (p=0.040) differed in individual games. The incidence of match injury during the congested fixture period was similar to rates reported outside this period but the mean lay-off duration of injuries was substantially shorter during the former (p<0.05). In summary, while the overall distance run and

Effects of age and spa treatment on match running performance over two consecutive games in highly trained young soccer players.

PubMed

Buchheit, Martin; Horobeanu, Cosmin; Mendez-Villanueva, Alberto; Simpson, Ben M; Bourdon, Pitre C

2011-03-01

The aim of this study was to examine the effect of age and spa treatment (i.e. combined sauna, cold water immersion, and jacuzzi) on match running performance over two consecutive matches in highly trained young soccer players. Fifteen pre- (age 12.8 ± 0.6 years) and 13 post- (15.9 ± 1 y) peak height velocity (PHV) players played two matches (Matches 1 and 2) within 48 h against the same opposition, with no specific between-match recovery intervention (control). Five post-PHV players also completed another set of two consecutive matches, with spa treatment implemented after the first match. Match running performance was assessed using a global positioning system with very-high-intensity running (> 16.1-19.0 km · h(-1)), sprinting distance (>19 km · h(-1)), and peak match speed determined. Match 2 very-high-intensity running was "possibly" impaired in post-PHV players (-9 ± 33%; ± 90% confidence limits), whereas it was "very likely" improved for the pre-PHV players (+27 ± 22%). The spa treatment had a beneficial impact on Match 2 running performance, with a "likely" rating for sprinting distance (+30 ± 67%) and "almost certain" for peak match speed (+6.4 ± 3%). The results suggest that spa treatment is an effective recovery intervention for post-PHV players, while its value in pre-PHV players is questionable.

Soccer Injuries in Players Aged 7 to 12 Years: A Descriptive Epidemiological Study Over 2 Seasons.

PubMed

Rössler, Roland; Junge, Astrid; Chomiak, Jiri; Dvorak, Jiri; Faude, Oliver

2016-02-01

As part of a risk-management approach, sound epidemiological data are needed to develop prevention programs. A recent review on soccer injuries of players younger than 19 years concluded that prospective data concerning children are lacking. To analyze the incidence and characteristics of soccer injuries in children aged 7 to 12 years. Descriptive epidemiological study. The present survey was a prospective descriptive epidemiological study on soccer injuries over 2 seasons in the Czech Republic and Switzerland. Exposure of players during training and match play (in hours) and injury data were reported by coaches via an Internet-based registration system. Location, type, and severity of injuries were classified according to an established consensus. Injury characteristics are presented as absolute numbers and injury incidence rates (injuries per 1000 hours of soccer exposure). An injury was defined as any physical complaint sustained during a scheduled training session or match play resulting in at least 1 of the following: (1) inability to complete the current match or training session, (2) absence from subsequent training sessions or matches, and (3) injury requiring medical attention. In total, 6038 player-seasons with 395,295 hours of soccer exposure were recorded. The mean (±SD) age of the players was 9.5 ± 2.0 years, and 3.9% of the participants were girls. A total of 417 injuries were reported. Most (76.3%) injuries were located in the lower limbs, with 15.6% located in the upper limbs. Joint and ligament injuries comprised 30.5%, contusions 22.5%, muscle and tendon injuries 18.5%, and fractures and bone injuries 15.4% of all injuries; 23.7% of injuries led to more than 28 days of absence from sport participation. The overall injury incidence was 0.61 (95% CI, 0.53-0.69) injuries per 1000 hours of soccer exposure during training sessions and 4.57 (95% CI, 4.00-5.23) during match play. Injury incidence rates increased with increasing age. The observed injury

Prevalence of Knee Osteoarthritis in 100 Athletically Active Veteran Soccer Players Compared With a Matched Group of 100 Military Personnel.

PubMed

Paxinos, Odysseas; Karavasili, Alexandra; Delimpasis, Georgios; Stathi, Afroditi

2016-06-01

Although knee injuries in professional soccer (football) have been extensively studied, the prevalence of knee osteoarthritis (OA) in veteran players is not well documented. To investigate the prevalence of knee OA in retired professional soccer players in comparison with a group of athletically active military personnel. Cross-sectional study; Level of evidence, 3. A group of 100 veteran Greek soccer players aged 35 to 55 years (mean [±SD] age, 46.90 ± 5.9 years) were examined for knee OA and were administered the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire. A matched group of 100 athletically active military personnel served as a comparison group. The sonographic prevalence of OA was significantly higher in the veteran soccer group (52%) than in the military group (33%) (n = 200; P = .010). This difference remained significant even after excluding participants with a history of knee surgery (44.1% vs 25.3%, respectively) (n = 151; P = .010). Femoral cartilage thickness was similar between the 2 groups (P = .473), while altered knee alignment had no effect on the prevalence of OA (P = .740). With the exception of perceived pain being more prevalent in the military group, there were no other statistically significant differences between the 2 groups in KOOS values. Veteran soccer players had a higher sonographic prevalence of knee OA but better pain scores than a matched group of athletically active military personnel. © 2016 The Author(s).

The preventive effect of a soccer-specific ankle brace on acute lateral ankle sprains in girls amateur soccer players: study protocol of a cluster-randomised controlled trial.

PubMed

Thijs, Karin; Huisstede, Bionka; Goedhart, Edwin; Backx, Frank

2017-07-27

Acute lateral ankle sprains are the single most often diagnosed injury in female soccer players and often result in an inability to play. This highlights the need for effective prevention strategies. Proprioceptive training and/or the use of an external support to decrease inversion of the ankle joint can prevent or reduce the number of acute lateral ankle sprains. The effectiveness of a soccer-specific ankle brace in reducing first-time and recurrent acute lateral ankle sprains has never been investigated in girl soccer players. If effective, ankle braces could be introduced into soccer. Cluster-randomised controlled trial. Girl amateur soccer players (aged 14-18 years) will be allocated to an intervention or control group. The intervention group will be instructed to wear soccer-specific ankle braces on both ankles during soccer training and matches; the control group will continue playing soccer as usual. Primary outcomes are the incidence and severity of acute lateral ankle sprains. Secondary outcomes are the prognostic value of generalised joint hypermobility and functional stability on the risk of acute lateral ankle sprains and compliance with the intervention. The findings from this study may provide evidence to support the use of a soccer-specific ankle brace to prevent lateral ankle sprains during soccer. We hypothesise that this brace will reduce the incidence of ankle sprains among young amateur girl soccer players by 50%. The prevention of such injuries will be beneficial to players, clubs and society. The Netherlands Trial Register (NTR): NTR6045; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

MRI findings in soccer players with long-standing adductor-related groin pain and asymptomatic controls.

PubMed

Branci, Sonia; Thorborg, Kristian; Bech, Birthe Højlund; Boesen, Mikael; Nielsen, Michael Bachmann; Hölmich, Per

2015-05-01

Soccer players are commonly affected by long-standing adductor-related groin pain (ARGP), but the clinical significance of MRI findings in these athletes is largely unknown. Our aims were (1) to evaluate whether MRI findings are associated with long-standing ARGP in soccer players, (2) to assess MRI findings in asymptomatic soccer players and non-soccer playing controls. This cross-sectional study included 28 male soccer players with long-standing ARGP, 17 male asymptomatic soccer players and 20 male asymptomatic non-soccer playing athletes of matching age and athletic exposure. Participants underwent identical standardised and reliable clinical examination, and MRI scans (3 T) of the pelvis performed by a blinded observer. Images were consensus rated by three blinded radiologists according to a standardised MRI evaluation protocol. The associations between clinical adductor-related findings and pathological MRI findings were investigated with χ(2) statistics and OR. Central disc protrusion (p=0.027) and higher grades of pubic bone marrow oedema (BMO; p=0.027) were significantly more present in symptomatic players than asymptomatic players. However, up to 71% of asymptomatic soccer players displayed different positive MRI findings, and asymptomatic soccer players had significantly higher odds (OR ranging from 6.3 to 13.3) for BMO, adductor tendinopathy and degenerative changes than non-soccer players. ARGP in soccer players was associated with central disc protrusion and higher grades of pubic BMO. Moreover, positive MRI findings were significantly more frequent in soccer players compared with non-soccer players irrespective of symptoms, suggesting that these MRI changes may be associated with soccer play itself rather than clinical symptoms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The Betting Odds Rating System: Using soccer forecasts to forecast soccer.

PubMed

Wunderlich, Fabian; Memmert, Daniel

2018-01-01

Betting odds are frequently found to outperform mathematical models in sports related forecasting tasks, however the factors contributing to betting odds are not fully traceable and in contrast to rating-based forecasts no straightforward measure of team-specific quality is deducible from the betting odds. The present study investigates the approach of combining the methods of mathematical models and the information included in betting odds. A soccer forecasting model based on the well-known ELO rating system and taking advantage of betting odds as a source of information is presented. Data from almost 15.000 soccer matches (seasons 2007/2008 until 2016/2017) are used, including both domestic matches (English Premier League, German Bundesliga, Spanish Primera Division and Italian Serie A) and international matches (UEFA Champions League, UEFA Europe League). The novel betting odds based ELO model is shown to outperform classic ELO models, thus demonstrating that betting odds prior to a match contain more relevant information than the result of the match itself. It is shown how the novel model can help to gain valuable insights into the quality of soccer teams and its development over time, thus having a practical benefit in performance analysis. Moreover, it is argued that network based approaches might help in further improving rating and forecasting methods.

The Betting Odds Rating System: Using soccer forecasts to forecast soccer

PubMed Central

Memmert, Daniel

2018-01-01

Betting odds are frequently found to outperform mathematical models in sports related forecasting tasks, however the factors contributing to betting odds are not fully traceable and in contrast to rating-based forecasts no straightforward measure of team-specific quality is deducible from the betting odds. The present study investigates the approach of combining the methods of mathematical models and the information included in betting odds. A soccer forecasting model based on the well-known ELO rating system and taking advantage of betting odds as a source of information is presented. Data from almost 15.000 soccer matches (seasons 2007/2008 until 2016/2017) are used, including both domestic matches (English Premier League, German Bundesliga, Spanish Primera Division and Italian Serie A) and international matches (UEFA Champions League, UEFA Europe League). The novel betting odds based ELO model is shown to outperform classic ELO models, thus demonstrating that betting odds prior to a match contain more relevant information than the result of the match itself. It is shown how the novel model can help to gain valuable insights into the quality of soccer teams and its development over time, thus having a practical benefit in performance analysis. Moreover, it is argued that network based approaches might help in further improving rating and forecasting methods. PMID:29870554

The reliability and validity of a soccer-specific nonmotorised treadmill simulation (intermittent soccer performance test).

PubMed

Aldous, Jeffrey W F; Akubat, Ibrahim; Chrismas, Bryna C R; Watkins, Samuel L; Mauger, Alexis R; Midgley, Adrian W; Abt, Grant; Taylor, Lee

2014-07-01

This study investigated the reliability and validity of a novel nonmotorised treadmill (NMT)-based soccer simulation using a novel activity category called a "variable run" to quantify fatigue during high-speed running. Twelve male University soccer players completed 3 familiarization sessions and 1 peak speed assessment before completing the intermittent soccer performance test (iSPT) twice. The 2 iSPTs were separated by 6-10 days. The total distance, sprint distance, and high-speed running distance (HSD) were 8,968 ± 430 m, 980 ± 75 m and 2,122 ± 140 m, respectively. No significant difference (p > 0.05) was found between repeated trials of the iSPT for all physiological and performance variables. Reliability measures between iSPT1 and iSPT2 showed good agreement (coefficient of variation: <4.6%; intraclass correlation coefficient: >0.80). Furthermore, the variable run phase showed HSD significantly decreased (p ≤ 0.05) in the last 15 minutes (89 ± 6 m) compared with the first 15 minutes (85 ± 7 m), quantifying decrements in high-speed exercise compared with the previous literature. This study validates the iSPT as a NMT-based soccer simulation compared with the previous match-play data and is a reliable tool for assessing and monitoring physiological and performance variables in soccer players. The iSPT could be used in a number of ways including player rehabilitation, understanding the efficacy of nutritional interventions, and also the quantification of environmentally mediated decrements on soccer-specific performance.

Cortical thinning in former professional soccer players.

PubMed

Koerte, Inga K; Mayinger, Michael; Muehlmann, Marc; Kaufmann, David; Lin, Alexander P; Steffinger, Denise; Fisch, Barbara; Rauchmann, Boris-Stephan; Immler, Stefanie; Karch, Susanne; Heinen, Florian R; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

2016-09-01

Soccer is the most popular sport in the world. Soccer players are at high risk for repetitive subconcussive head impact when heading the ball. Whether this leads to long-term alterations of the brain's structure associated with cognitive decline remains unknown. The aim of this study was to evaluate cortical thickness in former professional soccer players using high-resolution structural MR imaging. Fifteen former male professional soccer players (mean age 49.3 [SD 5.1] years) underwent high-resolution structural 3 T MR imaging, as well as cognitive testing. Fifteen male, age-matched former professional non-contact sport athletes (mean age 49.6 [SD 6.4] years) served as controls. Group analyses of cortical thickness were performed using voxel-based statistics. Soccer players demonstrated greater cortical thinning with increasing age compared to controls in the right inferolateral-parietal, temporal, and occipital cortex. Cortical thinning was associated with lower cognitive performance as well as with estimated exposure to repetitive subconcussive head impact. Neurocognitive evaluation revealed decreased memory performance in the soccer players compared to controls. The association of cortical thinning and decreased cognitive performance, as well as exposure to repetitive subconcussive head impact, further supports the hypothesis that repetitive subconcussive head impact may play a role in early cognitive decline in soccer players. Future studies are needed to elucidate the time course of changes in cortical thickness as well as their association with impaired cognitive function and possible underlying neurodegenerative process.

Somatotype and body composition analysis of Korean youth soccer players according to playing position for sports physiotherapy research

PubMed Central

Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Park, Byoung-Sun; Yang, Seung-Min; Jeon, Hye-Joo; Lee, Won-Deok; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

2015-01-01

[Purpose] The purpose of this study was to investigate the somatotype and physical characteristic differences among elite youth soccer players. [Subjects and Methods] In the present study, we evaluated twenty-two Korean youth soccer players in different playing positions. The playing positions were divided into forward (FW), midfielder (MF), defender (DF), and goalkeeper (GK). The participants’ lean body mass (LBM), fat free mass (FFM), fat mass (FM), and basal metabolic rate (BMR) were measured and their somatotype determined according to the Heath-Carter method. [Results] The youth soccer players had twelve ectomorphic, eight mesomorphic, and two central predominant types. The DFs were taller than, but otherwise similar in physical characteristics to the FWs and MFs. The GKs were taller and heavier than the other players; however, their somatotype components were not significantly different. LBM, FFM, and BMR were significantly higher in GKs than in FWs and MFs. Although LBM, FFM, and BMR values between GKs and DFs showed large differences, they were not statistically significant. [Conclusion] The present study may contribute to our understanding of the differences in somatotype and body composition of Korean youth soccer players involved in sports physiotherapy research. PMID:25995545

Somatotype and body composition analysis of Korean youth soccer players according to playing position for sports physiotherapy research.

PubMed

Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Park, Byoung-Sun; Yang, Seung-Min; Jeon, Hye-Joo; Lee, Won-Deok; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

2015-04-01

[Purpose] The purpose of this study was to investigate the somatotype and physical characteristic differences among elite youth soccer players. [Subjects and Methods] In the present study, we evaluated twenty-two Korean youth soccer players in different playing positions. The playing positions were divided into forward (FW), midfielder (MF), defender (DF), and goalkeeper (GK). The participants' lean body mass (LBM), fat free mass (FFM), fat mass (FM), and basal metabolic rate (BMR) were measured and their somatotype determined according to the Heath-Carter method. [Results] The youth soccer players had twelve ectomorphic, eight mesomorphic, and two central predominant types. The DFs were taller than, but otherwise similar in physical characteristics to the FWs and MFs. The GKs were taller and heavier than the other players; however, their somatotype components were not significantly different. LBM, FFM, and BMR were significantly higher in GKs than in FWs and MFs. Although LBM, FFM, and BMR values between GKs and DFs showed large differences, they were not statistically significant. [Conclusion] The present study may contribute to our understanding of the differences in somatotype and body composition of Korean youth soccer players involved in sports physiotherapy research.

The role of situational variables in analysing physical performance in soccer.

PubMed

Lago-Peñas, Carlos

2012-12-01

Performance analysis in sport is used to investigate the performance of teams and players across different sports. Research within this area, especially when focussing on the determinants of success, has grown rapidly in the last few years. During this time, the role of a new concept, 'situational variables' has emerged. This term includes the different game and situational conditions that may influence performance at a behavioural level. Given that soccer is dominated by strategic factors, it is reasonable to suggest that situational variables of match status (i.e. whether the team is winning, losing or drawing), quality of opposition (strong or weak), and match location (i.e. playing at home or away) may somehow influence the teams' and players' activities. These situational variables need to be analyzed in depth to understand their influence in team sports. The aim of this article was to examine the independent and interactive effects of situational variables on physical performance in elite soccer. The view that professional soccer players regulate their physical efforts according to the specific demands of individual matches and periods of the game is offered. In support of this argument results from recent studies are presented. Implications of this perspective for match analyst and coaches for evaluating performance are also considered.

The Role of Situational Variables in Analysing Physical Performance in Soccer

PubMed Central

Lago-Peñas, Carlos

2012-01-01

Performance analysis in sport is used to investigate the performance of teams and players across different sports. Research within this area, especially when focussing on the determinants of success, has grown rapidly in the last few years. During this time, the role of a new concept, ‘situational variables’ has emerged. This term includes the different game and situational conditions that may influence performance at a behavioural level. Given that soccer is dominated by strategic factors, it is reasonable to suggest that situational variables of match status (i.e. whether the team is winning, losing or drawing), quality of opposition (strong or weak), and match location (i.e. playing at home or away) may somehow influence the teams’ and players’ activities. These situational variables need to be analyzed in depth to understand their influence in team sports. The aim of this article was to examine the independent and interactive effects of situational variables on physical performance in elite soccer. The view that professional soccer players regulate their physical efforts according to the specific demands of individual matches and periods of the game is offered. In support of this argument results from recent studies are presented. Implications of this perspective for match analyst and coaches for evaluating performance are also considered. PMID:23487326

Changes in Passive Tension of the Hamstring Muscles During a Simulated Soccer Match.

PubMed

Marshall, Paul W; Lovell, Ric; Siegler, Jason C

2016-07-01

Passive muscle tension is increased after damaging eccentric exercise. Hamstring-strain injury is associated with damaging eccentric muscle actions, but no research has examined changes in hamstring passive muscle tension throughout a simulated sport activity. The authors measured hamstring passive tension throughout a 90-min simulated soccer match (SAFT90), including the warm-up period and every 15 min throughout the 90-min simulation. Passive hamstring tension of 15 amateur male soccer players was measured using the instrumented straight-leg-raise test. Absolute torque (Nm) and slope (Nm/°) of the recorded torque-angular position curve were used for data analysis, in addition to total leg range of motion (ROM). Players performed a 15-min prematch warm-up, then performed the SAFT90 including a 15-min halftime rest period. Reductions in passive stiffness of 20-50° of passive hip flexion of 22.1-29.2% (P < .05) were observed after the warm-up period. During the SAFT90, passive tension increased in the latter 20% of the range of motion of 10.1-10.9% (P < .05) concomitant to a 4.5% increase in total hamstring ROM (P = .0009). The findings of this study imply that hamstring passive tension is reduced after an active warm-up that includes dynamic stretching but does not increase in a pattern suggestive of eccentric induced muscle damage during soccer-specific intermittent exercise. Hamstring ROM and passive tension increases are best explained by improved stretch tolerance.

Sprint profile of professional female soccer players during competitive matches: Female Athletes in Motion (FAiM) study.

PubMed

Vescovi, Jason D

2012-01-01

The aim of this study was to determine sprint profiles of professional female soccer players and evaluate how various speed thresholds impact those outcomes. Seventy-one professional players competing in full matches were assessed repeatedly during 12 regular season matches using a Global Positioning System (GPS). Locomotion ≥18 km · h⁻¹ was defined as sprinting and each event was classified into: Zone 1: 18.0-20.9 km· h⁻¹; Zone 2: 21.0-22.9 km · h⁻¹; Zone 3: 23.0-24.9 km · h⁻¹ and Zone 4: >25 km · h⁻¹. Outcomes included: duration (s), distance (m), maximum speed (km · h⁻¹), duration since previous sprint (min) and proportion of total sprint distance. In total 5,019 events were analysed from 139 player-matches. Mean sprint duration, distance, maximum speed and time between sprints were 2.3 ± 1.5 s, 15.1 ± 9.4 m, 21.8 ± 2.3 km· h⁻¹, and 2.5 ± 2.5 min, respectively. Mean sprint distances were 657 ± 157, 447 ± 185, and 545 ± 217 m for forwards, midfielders and defenders, respectively (P ≤ 0.046). Midfielders had shorter sprint duration (P = 0.023), distance (P ≤ 0.003) and maximum speed (P < 0.001), whereas forwards performed more sprints per match (43 ± 10) than midfielders (31 ± 11) and defenders (36 ± 12) (P ≤ 0.016). Forty-five percent, 29%, 15%, and 11% of sprints occurred in sprint Zones 1, 2, 3 and 4, respectively. This group of professional female soccer players covered 5.3 ± 2.0% of total distance ≥18 km · h⁻¹ with positional differences and percent decrements distinct from other previously identified elite players. These data should guide the development of high intensity and sprint thresholds for elite-standard female soccer players.

Exercise physiology and nutritional perspectives of elite soccer refereeing.

PubMed

Schenk, K; Bizzini, M; Gatterer, H

2018-03-01

Referees are an integral part of soccer, and their performance is fundamental for regular match flow, irrespective of the competition level or age classes. So far, scientific interest was mainly limited to aspects of exercise physiology and match performance of soccer referees, whereas recommendations for nutrition were adopted from active professional soccer. In contrast to elite soccer players, most referees are non-professional and engaged in different occupations. Furthermore, elite referees and soccer players differ in regard to age, body composition, aerobic capacity, and training load. Thus, referees' caloric needs and recommended daily carbohydrate intake may generally be lower compared to active soccer players, with higher intakes limited to periods of increased training load and match days or for referees engaged in physical demanding occupations. With respect to fluid intake, pre-match and in-match hydration strategies generally valid in sports are recommended also for referees to avoid cognitive and physical performance loss, especially when officiating in extreme climates and altitude. In contrast to elite soccer, professional assistance concerning nutrition and training is rarely available for national elite referees of most countries. Therefore, special attention on education about adequate nutrition and fluid intake, about the dietary prevention of deficiencies (iron in female referees, vitamin D irrespective of sex and age), and basic precautions for travels abroad is warranted. In conclusion, the simple adoption of nutritional considerations from active soccer for referees may not be appropriate. Recommendations should respect gender differences, population-specific physical characteristics, and demands just as well as individual characteristics and special needs. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Analysis of Injury Incidences in Male Professional Adult and Elite Youth Soccer Players: A Systematic Review.

PubMed

Pfirrmann, Daniel; Herbst, Mark; Ingelfinger, Patrick; Simon, Perikles; Tug, Suzan

2016-05-01

The incidence of injury for elite youth and professional adult soccer players is an important concern, but the risk factors for these groups are different. To summarize and compare the injury incidences and injury characteristics of male professional adult and elite youth soccer players. We searched MEDLINE and Web of Science using the search terms elite, international, European, soccer, football, injury, injuries, epidemiology, incidence, prevalence, not female, not American football, and not rugby. We also used the search terms professional for studies on professional adult soccer players and high-level, soccer academy, youth, adolescent, and young for studies on elite youth soccer players. Eligible studies were published in English, had a prospective cohort design, and had a minimum study period of 6 months. To ensure that injury data were assessed in relationship to the athlete's individual exposure, we included only studies that reported on injuries and documented exposure volume. Two independent reviewers applied the selection criteria and assessed the quality of the studies. A total of 676 studies were retrieved from the literature search. Eighteen articles met the inclusion criteria: 6 for elite youth and 12 for professional adult soccer players. Injury rates were higher for matches than for training for both youth and adult players. Youth players had a higher incidence of training injuries than professionals. Efforts must be made to reduce the overall injury rate in matches. Therefore, preventive interventions, such as adequately enforcing rules and focusing on fair play, must be analyzed and developed to reduce match-related injury incidences. Reducing training injuries should be a particular focus for youth soccer players.

The role of motion analysis in elite soccer: contemporary performance measurement techniques and work rate data.

PubMed

Carling, Christopher; Bloomfield, Jonathan; Nelsen, Lee; Reilly, Thomas

2008-01-01

The optimal physical preparation of elite soccer (association football) players has become an indispensable part of the professional game, especially due to the increased physical demands of match-play. The monitoring of players' work rate profiles during competition is now feasible through computer-aided motion analysis. Traditional methods of motion analysis were extremely labour intensive and were largely restricted to university-based research projects. Recent technological developments have meant that sophisticated systems, capable of quickly recording and processing the data of all players' physical contributions throughout an entire match, are now being used in elite club environments. In recognition of the important role that motion analysis now plays as a tool for measuring the physical performance of soccer players, this review critically appraises various motion analysis methods currently employed in elite soccer and explores research conducted using these methods. This review therefore aims to increase the awareness of both practitioners and researchers of the various motion analysis systems available, and identify practical implications of the established body of knowledge, while highlighting areas that require further exploration.

The peak velocity derived from the Carminatti Test is related to physical match performance in young soccer players.

PubMed

Fernandes-da-Silva, Juliano; Castagna, Carlo; Teixeira, Anderson Santiago; Carminatti, Lorival José; Guglielmo, Luiz Guilherme Antonacci

2016-12-01

The aim of this study was to examine the relationship between the peak velocity derived from the Carminatti Test (T-CAR) (PV T-CAR ) and physical match performance in young soccer players. Thirty-three youth soccer players were recruited from 2 non-professional clubs. Friendly matches and small-sided game were performed. Physical match demands were assessed using Global Positioning System (GPS) technology. On a separate occasion, the players were submitted to the T-CAR. Players were categorised into 3 groups based on their T-CAR performance: Low (PV T-CAR  ≤ P33), Intermediate (P33 > PV T-CAR  < P66) and High (PV T-CAR  ≥ P66). The PV T-CAR (15.5 ± 0.7 km·h -1 ) was significantly related to high-intensity activities (HIA; r = 0.78, P < 0.001), high-intensity running (HIR; r = 0.66, P < 0.001), sprinting (r = 0.62, P < 0.001) and total distance (TD) covered (r = 0.47, P < 0.01) during friendly matches. The PV T-CAR was strongly correlated with the amount of HIA (r = 0.81, P < 0.001), HIR (r = 0.85, P < 0.001) and TD covered (r = 0.81, P < 0.001) during small-sided game. No significant correlation was observed between the PV T-CAR and distance of sprinting (r = 0.49, P = 0.067) during small-side game. Furthermore, players in the High group covered significantly more TD (10%) and did more HIA (42%), sprinting (31%) and HIR (25%) during friendly matches compared to the players classified as having Low performance on the T-CAR. These differences still remained after adjusting for chronological age (CA), maturity and body size. In conclusion, the current study gives empirical support to the ecological and construct validity of this novel field test (T-CAR) as an indicator of match-related physical performance in young soccer players during pubertal years.

Physiological characteristics of badminton match play.

PubMed

Faude, Oliver; Meyer, Tim; Rosenberger, Friederike; Fries, Markus; Huber, Günther; Kindermann, Wilfried

2007-07-01

The present study aimed at examining the physiological characteristics and metabolic demands of badminton single match play. Twelve internationally ranked badminton players (eight women and four men) performed an incremental treadmill test [VO(2peak = )50.3 +/- 4.1 ml min(-1) kg(-1) (women) and 61.8 +/- 5.9 ml min(-1) kg(-1) (men), respectively]. On a separate day, they played a simulated badminton match of two 15 min with simultaneous gas exchange (breath-by-breath) and heart rate measurements. Additionally, blood lactate concentrations were determined before, after 15 min and at the end of the match. Furthermore, the duration of rallies and rests in between, the score as well as the number of shots per rally were recorded. A total of 630 rallies was analysed. Mean rally and rest duration were 5.5 +/- 4.4 s and 11.4 +/- 6.0 s, respectively, with an average 5.1 +/- 3.9 shots played per rally. Mean oxygen uptake (VO(2)), heart rate (HR), and blood lactate concentrations during badminton matches were 39.6 +/- 5.7 ml min(-1) kg(-1) (73.3% VO(2peak)), 169 +/- 9 min(-1) (89.0% HR(peak)) and 1.9 +/- 0.7 mmol l(-1), respectively. For a single subject 95% confidence intervals for VO(2) and HR during match play were on average 45.7-100.9% VO(2peak) and 78.3-99.8% HR(peak). High average intensity of badminton match play and considerable variability of several physiological variables demonstrate the importance of anaerobic alactacid and aerobic energy production in competitive badminton. A well-developed aerobic endurance capacity seems necessary for fast recovery between rallies or intensive training workouts.

Repeated change-of-direction test for collegiate male soccer players.

PubMed

Mizuguchi, S; Gray, H; Calabrese, L S; Haff, G G; Sands, W A; Ramsey, M W; Cardinale, M; Stone, M H

2014-08-01

The aim of the study was to investigate the applicability of a repeated change-of-direction (RCoD) test for NCAA Division-I male soccer players. The RCoD test consisted of 5 diagonal direction changes per repetition with a soccer ball to be struck at the end. Each player performed 15 repetitions with approximately 10 seconds to jog back between repetitions. Data were collected in two sessions. In the first session, 13 players were examined for heart rate responses and blood lactate concentrations. In the second session, 22 players were examined for the test's ability to discriminate the primary from secondary players (78.0±16.1 and 10.4±13.3 minutes per match, respectively). Heart rate data were available only from 9 players due to artifacts. The peak heart rate (200.2±6.6 beats∙min-1: 99.9±3.0% maximum) and blood lactate concentration (14.8±2.4 mmol∙L-1 immediately after) resulted in approximately 3.5 and 6.4-fold increases from the resting values, respectively. These values appear comparable to those during intense periods of soccer matches. In addition, the average repetition time of the test was found to discriminate the primary (4.85±0.23 s) from the secondary players (5.10±0.24 s) (P=0.02). The RCoD test appears to induce physiological responses similar to intense periods of soccer matches with respect to heart rate and blood lactate concentration. Players with better average repetition times tend to be those who play major minutes.

The Energy Cost of Running with the Ball in Soccer.

PubMed

Piras, Alessandro; Raffi, Milena; Atmatzidis, Charalampos; Merni, Franco; Di Michele, Rocco

2017-11-01

Running with the ball is a soccer-specific activity frequently used by players during match play and training drills. Nevertheless, the energy cost (EC) of on-grass running with the ball has not yet been determined. The purpose of this study was therefore to assess the EC of constant-speed running with the ball, and to compare it with the EC of normal running. Eight amateur soccer players performed two 6- min runs at 10 km/h on artificial turf, respectively with and without the ball. EC was measured with indirect calorimetry and, furthermore, estimated with a method based on players' accelerations measured with a GPS receiver. The EC measured with indirect calorimetry was higher in running with the ball (4.60±0.42 J/kg/m) than in normal running (4.19±0.33 J/kg/m), with a very likely moderate difference between conditions. Instead, a likely small difference was observed between conditions for EC estimated from GPS data (4.87±0.07 vs. 4.83±0.08 J/kg/m). This study sheds light on the energy expenditure of playing soccer, providing relevant data about the EC of a typical soccer-specific activity. These findings may be a reference for coaches to precisely determine the training load in drills with the ball, such as soccer-specific circuits or small-sided games. © Georg Thieme Verlag KG Stuttgart · New York.

Intensity of tennis match play

PubMed Central

Fernandez, J; Mendez‐Villanueva, A; Pluim, B M

2006-01-01

This review focuses on the characteristics of tennis players during match play and provides a greater insight into the energy demands of tennis. A tennis match often lasts longer than an hour and in some cases more than five hours. During a match there is a combination of periods of maximal or near maximal work and longer periods of moderate and low intensity activity. Match intensity varies considerably depending on the players' level, style, and sex. It is also influenced by factors such as court surface and ball type. This has important implications for the training of tennis players, which should resemble match intensity and include interval training with appropriate work to rest ratios. PMID:16632566

Soccer injuries in children.

PubMed

Paterson, Anne

2009-12-01

Soccer is the most popular sport in the world, with FIFA recognising more than 265 million amateur players. Despite the fact that soccer is a contact sport, it is perceived to be relatively safe to play, a factor that has contributed to its status as the fastest growing team sport in the USA. Acute and minor injuries predominate in the statistics, with contusions and abrasions being the most commonly recorded. As would be expected, the majority of soccer injuries are to the lower limbs, with serious truncal and spinal trauma being rare. This article examines the type and anatomic location of injuries sustained by children and adolescents who play soccer, and the main mechanisms whereby such injuries occur. The risk factors underpinning injury occurrence are considered, along with injury avoidance tactics.

Analysis of Injury Incidences in Male Professional Adult and Elite Youth Soccer Players: A Systematic Review

PubMed Central

Pfirrmann, Daniel; Herbst, Mark; Ingelfinger, Patrick; Simon, Perikles; Tug, Suzan

2016-01-01

Context:  The incidence of injury for elite youth and professional adult soccer players is an important concern, but the risk factors for these groups are different. Objective:  To summarize and compare the injury incidences and injury characteristics of male professional adult and elite youth soccer players. Data Sources:  We searched MEDLINE and Web of Science using the search terms elite, international, European, soccer, football, injury, injuries, epidemiology, incidence, prevalence, not female, not American football, and not rugby. We also used the search terms professional for studies on professional adult soccer players and high-level, soccer academy, youth, adolescent, and young for studies on elite youth soccer players. Study Selection:  Eligible studies were published in English, had a prospective cohort design, and had a minimum study period of 6 months. To ensure that injury data were assessed in relationship to the athlete's individual exposure, we included only studies that reported on injuries and documented exposure volume. Data Extraction:  Two independent reviewers applied the selection criteria and assessed the quality of the studies. Data Synthesis:  A total of 676 studies were retrieved from the literature search. Eighteen articles met the inclusion criteria: 6 for elite youth and 12 for professional adult soccer players. Conclusions:  Injury rates were higher for matches than for training for both youth and adult players. Youth players had a higher incidence of training injuries than professionals. Efforts must be made to reduce the overall injury rate in matches. Therefore, preventive interventions, such as adequately enforcing rules and focusing on fair play, must be analyzed and developed to reduce match-related injury incidences. Reducing training injuries should be a particular focus for youth soccer players. PMID:27244125

The Importance of Strength and Power on Key Performance Indicators in Elite Youth Soccer.

PubMed

Wing, Christopher E; Turner, Anthony N; Bishop, Chris J

2018-01-24

The purpose of this investigation was to examine the importance of strength and power in relation to key performance indicators (KPI's) within competitive soccer match play. This was achieved through using an experimental approach where fifteen subjects were recruited from a professional soccer club's scholarship squad during the 2013/14 season. Following anthropometric measures, power and strength were assessed across a range of tests which included the squat jump (SJ), countermovement jump (CMJ), 20 metre (m) sprint and arrowhead change of direction test. A predicted 1-repetition maximum (RM) was also obtained for strength by performing a 3RM test for both the back squat and bench press and a total score of athleticism (TSA) was provided by summing z-scores for all fitness tests together, providing one complete score for athleticism. Performance analysis data was collected during 16 matches for the following KPIs: passing, shooting, dribbling, tackling and heading. Alongside this, data concerning player ball involvements (touches) was recorded. Results showed that there was a significant correlation (p < 0.05) between CMJ (r = 0.80), SJ (r = 0.79) and TSA (r = 0.64) in relation to heading success. Similarly, a significant correlation (p < 0.05) between predicted 1RM squat strength and tackle success (r = 0.61). These data supports the notion that strength and power training are important to soccer performance, particularly when players are required to win duels of a physical nature. There were no other relationships found between the fitness data and the KPI's recorded during match play which may indicate that other aspects of player's development such as technical skill, cognitive function and sensory awareness are more important for soccer-specific performance.

The Brazilian World Cup: too hot for soccer?

PubMed

Lucena, Rebecca Luna; Steinke, Ercília Torres; Pacheco, Christina; Vieira, Lucas Lima; Betancour, Maribel Olaya; Steinke, Valdir Adilson

2017-12-01

The main objective of this research was to analyze the climate data for the host cities of the soccer World Cup held in Brazil in June and July 2014. A great deal of criticism was expressed about the Brazilian climate in the national and international press and media in the run-up to the competition, suggesting that the air temperature and relative air humidity would be the main adversaries of the soccer teams, especially those from Europe, during the competition. An analysis of the weather was done at the places and times of each of the 64 matches held. A human thermal comfort index was calculated (discomfort index (DI)) for each of the matches in order to discover the real climatic conditions in the host cities during the 2014 World Cup and their potential influence on the teams and human comfort in general. During the 2014 World Cup, only two matches were played at temperatures above 30 °C, representing a negligible percentage of the total number of matches. The air temperature for over half the matches (53%) was 20-25 °C. The results showed the air temperature and relative humidity data analyzed here both individually and in the form of an index indicate that the World Cup held in Brazil in 2014 did not put any of the players at risk due to extreme heat.

The Brazilian World Cup: too hot for soccer?

NASA Astrophysics Data System (ADS)

Lucena, Rebecca Luna; Steinke, Ercília Torres; Pacheco, Christina; Vieira, Lucas Lima; Betancour, Maribel Olaya; Steinke, Valdir Adilson

2017-12-01

The main objective of this research was to analyze the climate data for the host cities of the soccer World Cup held in Brazil in June and July 2014. A great deal of criticism was expressed about the Brazilian climate in the national and international press and media in the run-up to the competition, suggesting that the air temperature and relative air humidity would be the main adversaries of the soccer teams, especially those from Europe, during the competition. An analysis of the weather was done at the places and times of each of the 64 matches held. A human thermal comfort index was calculated (discomfort index (DI)) for each of the matches in order to discover the real climatic conditions in the host cities during the 2014 World Cup and their potential influence on the teams and human comfort in general. During the 2014 World Cup, only two matches were played at temperatures above 30 °C, representing a negligible percentage of the total number of matches. The air temperature for over half the matches (53%) was 20-25 °C. The results showed the air temperature and relative humidity data analyzed here both individually and in the form of an index indicate that the World Cup held in Brazil in 2014 did not put any of the players at risk due to extreme heat.

Distinguishing Playing Status Through a Functionally Relevant Performance Measure in Female Division I Collegiate Soccer Athletes.

PubMed

Magrini, Mitchel A; Colquhoun, Ryan J; Sellers, John H; Conchola, Eric C; Hester, Garrett M; Thiele, Ryan M; Pope, Zach K; Smith, Doug B

2017-06-08

Although soccer is predominately an endurance sport, high velocity movements may be an important indicator of athletic success. The purpose of this investigation was to establish whether squat jumps (SJ) can differentiate starters from non-starters with a female collegiate division I soccer team. Eighteen female division I soccer athletes were separated into two groups: 9 starters (age: 19.5 ± 1.0; mass = 64.8 ± 11.5 kg; height = 167.5 ± 7.7 cm; games started = 18.2 ± 4.7; minutes played = 1633.8 ± 478.2 min) and 9 non-starters (age: 19.4 ± 1.4 years; mass = 63.3 ± 4.2 kg; height = 164.7 ± 6.8 cm; games started 0.7 ± 1.3; minutes played 158.2 ± 269.3). Each athlete performed 3 maximal SJs at a starting knee angle of 110° without arm swing. Each participant's SJ height, mean power (MP), peak power (PP), mean velocity (MV), and peak velocity (PV) were measured during each attempt by a linear position transducer (LPT). No statistically significant differences (p ≥ 0.05) in MP and PP between the starters and non-starters were observed. However, starters performed significantly better than non-starters in SJ height (p = 0.002), MV (p = 0.025), and PV (p = 0.015). Additionally, SJ height was strongly correlated with MV (r = 0.628) and PV (r = 0.647). These findings suggest that SJ height, MV and PV, may be important variables for discriminating differences between starters and non-starters in division I female soccer athletes and a strong indicator of explosive performance.

The effect of an early dismissal on player work-rate in a professional soccer match.

PubMed

Carling, Christopher; Bloomfield, Jonathan

2010-01-01

The aim of this study was to examine the effects of an early dismissal (after 5-min play) on work-rate in a professional soccer match. A computerised player tracking system was used to assess the work-rates of seven players who completed the match on a team with 10 players. A minute-by-minute analysis of the remaining 91min following the dismissal was performed for the total distance covered, the distance covered in five categories of movement intensity and the recovery time between high-intensity efforts for each player. The data were calculated for each half and for three equal intervals within each half and profiled against normative data for the same players obtained from the analysis of 15 games in the same season. Following the dismissal, the players covered a greater total distance than normal (p<0.025), particularly in moderate-intensity activities (p<0.01) and had shorter recovery times between high-intensity efforts (p<0.025). In contrast, there was a significant reduction between game halves for total distance covered at both the highest (p<0.025) and lowest running intensities (p<0.01). However, there were no differences in high-intensity activities across the three intervals in the second-half. These findings suggest that in 11 vs. 11, players may not always utilise their full physical potential as this match illustrated an increase in overall work-rate when reduced to 10 players. However, as a team with 10 players is likely to incur higher levels of fatigue, tactical alterations may be necessary and/or players may adopt a pacing strategy to endure the remainder of the match. Copyright (c) 2008 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Soccer injuries and recovery in Dutch male amateur soccer players: results of a prospective cohort study.

PubMed

van Beijsterveldt, Anne-Marie; Steffen, Kathrin; Stubbe, Janine H; Frederiks, Janet E; van de Port, Ingrid G L; Backx, Frank J G

2014-07-01

To describe characteristics of outdoor soccer injury and recovery among Dutch soccer players. Prospective cohort study. The 2009-2010 competitive season (33 weeks). Four hundred fifty-six Dutch male soccer players of 23 amateur teams. Coaches recorded individual exposure to all soccer activities. Paramedics or sports trainers collected information on the occurrence (e.g., location, type, circumstances) and consequences (eg, absenteeism, medical treatment) of injuries. In total, 424 time-loss injuries were sustained by 60% (n = 274) of the players, with 23% (n = 105) having more than 1 injury. This corresponds to an overall density of 9.6 (8.7-10.5) injuries per 1000 player hours; 3.9 (3.3-4.7) in training sessions and 20.4 (18.1-23.1) in soccer matches. Almost 30% (n = 123) of the injuries lasted for more than 1 month, 14% (n = 58) were reinjuries (causing longer absence than new injuries), and 54% (n = 230) of the injuries were given medical treatment. The most common diagnoses were muscle/tendon (38%) or joint/ligament injuries (23%) of the lower extremities. After regaining the ability to fully take part in soccer training or matches, 27.4% of the players (n = 116) still reported complaints. Two recommendations based on the above-mentioned results are (1) prevention should primarily focus on these most common diagnoses and (2) players resuming soccer activities after an injury should be given special attention to resolve the remaining complaints and to prevent reinjuries.

World soccer cup as a trigger of cardiovascular events.

PubMed

Borges, Daniel Guilherme Suzuki; Monteiro, Rosane Aparecida; Schmidt, André; Pazin-Filho, Antonio

2013-06-01

Acute coronary syndromes are the major cause of death in Brazil and in the world. External stimuli, known also as triggers, such as emotional state and activity, may generate physiopathological changes that can trigger acute coronary syndromes. Among the studied triggers, the impact of stressful events, such as soccer championships, are controversial in literature and there is no effective data on the Brazilian population. To evaluate the acute effects of environmental stress induced by soccer games of the World Soccer Cup on increased incidence of cardiovascular diseases in Brazil. Public data were obtained from the Unified Health System (Sistema Único de Saúde), regarding hospital admissions that had the International Code Disease of acute coronary syndromes from May to August, in 1998, 2002, 2006 and 2010 (155,992 admissions). Analysis was restricted to patients older than 35 years and admitted by clinical specialties. The incidence of myocardial infarction, angina and mortality were compared among days without World Cup soccer games (Group I: 144,166; 61.7 ± 12.3; 59.4% males); on days when there were no Brazil's soccer team matches (Group II: 9,768; 61.8 ± 12.3; 60.0% males); and days when there were Brazil's soccer team matches (Group III; 2,058; 61.6 ± 12.6; 57.8% males). Logistic regression was used to adjust to age, gender, population density and number of medical assistance units. The incidence of myocardial infarction increased during the period of World Cup soccer games (1.09; 95%CI = 1.05-1.15) and days when there were Brazil's matches (1.16; 95%CI = 1.06-1.27). There was no impact on mortality during the Cup (1.00; CI 95% = 0.93-1.08) and Brazil's matches (1.04; 95%CI = 0.93-1.22). World Cup soccer games and, specially, Brazil's matches have an impact on the incidence of myocardial infarction, but not on in-hospital mortality.

Injuries of the obturator muscles in professional soccer players.

PubMed

Wong-On, Manuel; Turmo-Garuz, Antonio; Arriaza, Rafael; Gonzalez de Suso, Jose Manuel; Til-Perez, Luis; Yanguas-Leite, Xavier; Diaz-Cueli, David; Gasol-Santa, Xavier

2017-02-10

Obturator externus and internus muscular tears are uncommon injuries. Only a few case reports exist, mainly in high-level athletes. Our aim is to describe a series of obturator externus and internus muscular tears in professional soccer players. Injury data from four teams from the First Division of the Spanish Soccer League were collected over a total of four seasons. Any soccer player who sustained an injury to either the obturator externus or internus identified on magnetic resonance (MRI) was included. All injured players were treated non-operatively with a goal of returning to play as fast as possible. Sixteen players sustained injuries to the obturator externus and internus during matches or training sessions. The main complaint was anterior hip pain with a physical examination showing pain during internal rotation or external rotation of the flexed hip. The MRI documented 12 muscular tears of the obturator externus, and 4 muscular tears of the obturator internus. All injuries were treated conservatively based on physical therapy, analgesic medications, and underwent a symptoms-based rehabilitation protocol. Mean return to play was 11.5  ±  8.8 days. Although uncommon, tears of the obturator externus and internus occur in professional soccer players. The MRI scan was essential to the location, classification, and evaluation of the injury size. The clinical relevance of our investigation is based on the relatively benign prognosis of these injuries. IV.

The effect of high vs. low carbohydrate diets on distances covered in soccer.

PubMed

Souglis, Athanasios G; Chryssanthopoulos, Costas I; Travlos, Antonios K; Zorzou, Amalia E; Gissis, Ioannis T; Papadopoulos, Christos N; Sotiropoulos, Aristomenis A

2013-08-01

The purpose of this study was to compare the distances covered during a 11-a-side soccer match after players had consumed either a high carbohydrate (CHO) or a low CHO diet. Twenty-two male professional soccer players formed 2 teams (A and B), of similar age, body characteristics, and training experience. The 2 teams played against each other twice with a week interval between. For 3.5 days before the first match, the players of team A followed a high CHO diet that provided 8 g CHO per kg body mass (BM) (HC), whereas team B players followed a low CHO diet that provided 3 g CHO per kg BM (LC) for the same time period. Before the second match the dietary treatment was reversed and followed for the same time period. Training during the study was controlled, and distances covered were measured using global positioning system technology. Every player covered a greater total distance in HC compared with the distance covered in LC (HC: 9,380 ± 98 m vs. LC: 8,077 ± 109 m; p < 0.01). All distances covered from easy jogging (7.15 km·h-1) to sprinting (24.15 km·h-1) were also higher in HC compared with LC (p < 0.01). When players followed the HC treatment, they won the match (team A vs. team B: 3-1 for the first game and 1-2 for the second game). The HC diet probably helped players to cover a greater distance compared with LC. Soccer players should avoid eating a low (3 g CHO per kg BM) CHO diet 3-4 days before an important soccer match and have a high CHO intake that provides at least 8 g CHO per kg BM.

Influence of nutrient intake on antioxidant capacity, muscle damage and white blood cell count in female soccer players

PubMed Central

2012-01-01

Background Soccer is a form of exercise that induces inflammatory response, as well as an increase in free radicals potentially leading to muscle injury. Balanced nutritional intake provides important antioxidant vitamins, including vitamins A, C and E, which may assist in preventing exercise-related muscle damage. The purpose of the present study was to determine the effect of macro/micronutrient intake on markers of oxidative stress, muscle damage, inflammatory and immune response in female soccer players. Methods Twenty-eight female players belonging to two soccer teams of the same professional soccer club participated in this study after being informed about the aims and procedures and after delivering written consent. Each team completed an 8-day dietary record and played one competition match the same week. Participants were divided into two groups: the REC group (who complied with recommended intakes) and the NO-REC group (who were not compliant). Laboratory blood tests were carried out to determine hematological, electrolytic and hormonal variables, as well as to monitor markers of cell damage and oxidative stress. Blood samples were obtained 24 h before, immediately after and 18 h after official soccer matches. Student t-test or Mann–Whitney U-test was used to compare both groups throughout the match. Results At rest, we observed that the REC group had higher levels of total antioxidant status (TAS), glutathione peroxidase (GPx), and lower levels of creatine kinase (CK) and lactate dehydrogenase (LDH) in comparison to the NO-REC group. Immediately after the match, levels of TAS, GPx, superoxide dismutase (SOD), LDH and % lymphocytes were higher and the % of neutrophils were lower in the REC group compared to the NO-REC group. These differences were also maintained 18 h post-match, only for TAS and GPx. Conclusions Our data reveal an association between nutritional intake and muscle damage, oxidative stress, immunity and inflammation markers. The benefit

Altered Neurochemistry in Former Professional Soccer Players without a History of Concussion

PubMed Central

Lin, Alexander P.; Muehlmann, Marc; Merugumala, Sai; Liao, Huijun; Starr, Tyler; Kaufmann, David; Mayinger, Michael; Steffinger, Denise; Fisch, Barbara; Karch, Susanne; Heinen, Florian; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A.; Zafonte, Ross; Shenton, Martha E.

2015-01-01

Abstract Soccer is played by more than 250 million people worldwide. Repeatedly heading the ball may place soccer players at high risk for repetitive subconcussive head impacts (RSHI). This study evaluates the long-term effects of RSHI on neurochemistry in athletes without a history of clinically diagnosed concussion, but with a high exposure to RSHI. Eleven former professional soccer players (mean age 52.0±6.8 years) and a comparison cohort of 14 age- and gender-matched, former non-contact sport athletes (mean age 46.9±7.9 years) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation. In the soccer players a significant increase was observed in both choline (Cho), a membrane marker, and myo-inositol (ml), a marker of glial activation, compared with control athletes. Additionally, ml and glutathione (GSH) were significantly correlated with lifetime estimate of RSHI within the soccer group. There was no significant difference in neurocognitive tests between groups. Results of this study suggest an association between RSHI in soccer players and MRS markers of neuroinflammation, suggesting that even subconcussive head impacts affect the neurochemistry of the brain and may precede neurocognitive changes. Future studies will need to determine the role of neuroinflammation in RSHI and the effect on neurocognitive function. PMID:25843317

Altered Neurochemistry in Former Professional Soccer Players without a History of Concussion.

PubMed

Koerte, Inga K; Lin, Alexander P; Muehlmann, Marc; Merugumala, Sai; Liao, Huijun; Starr, Tyler; Kaufmann, David; Mayinger, Michael; Steffinger, Denise; Fisch, Barbara; Karch, Susanne; Heinen, Florian; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

2015-09-01

Soccer is played by more than 250 million people worldwide. Repeatedly heading the ball may place soccer players at high risk for repetitive subconcussive head impacts (RSHI). This study evaluates the long-term effects of RSHI on neurochemistry in athletes without a history of clinically diagnosed concussion, but with a high exposure to RSHI. Eleven former professional soccer players (mean age 52.0±6.8 years) and a comparison cohort of 14 age- and gender-matched, former non-contact sport athletes (mean age 46.9±7.9 years) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation. In the soccer players a significant increase was observed in both choline (Cho), a membrane marker, and myo-inositol (ml), a marker of glial activation, compared with control athletes. Additionally, ml and glutathione (GSH) were significantly correlated with lifetime estimate of RSHI within the soccer group. There was no significant difference in neurocognitive tests between groups. Results of this study suggest an association between RSHI in soccer players and MRS markers of neuroinflammation, suggesting that even subconcussive head impacts affect the neurochemistry of the brain and may precede neurocognitive changes. Future studies will need to determine the role of neuroinflammation in RSHI and the effect on neurocognitive function.

Hypernetworks Reveal Compound Variables That Capture Cooperative and Competitive Interactions in a Soccer Match.

PubMed

Ramos, João; Lopes, Rui J; Marques, Pedro; Araújo, Duarte

2017-01-01

The combination of sports sciences theorization and social networks analysis (SNA) has offered useful new insights for addressing team behavior. However, SNA typically represents the dynamics of team behavior during a match in dyadic interactions and in a single cumulative snapshot. This study aims to overcome these limitations by using hypernetworks to describe illustrative cases of team behavior dynamics at various other levels of analyses. Hypernetworks simultaneously access cooperative and competitive interactions between teammates and opponents across space and time during a match. Moreover, hypernetworks are not limited to dyadic relations, which are typically represented by edges in other types of networks. In a hypernetwork, n-ary relations (with n > 2) and their properties are represented with hyperedges connecting more than two players simultaneously (the so-called simplex -plural, simplices ). Simplices can capture the interactions of sets of players that may include an arbitrary number of teammates and opponents. In this qualitative study, we first used the mathematical formalisms of hypernetworks to represent a multilevel team behavior dynamics, including micro (interactions between players), meso (dynamics of a given critical event, e.g., an attack interaction), and macro (interactions between sets of players) levels. Second, we investigated different features that could potentially explain the occurrence of critical events, such as, aggregation or disaggregation of simplices relative to goal proximity. Finally, we applied hypernetworks analysis to soccer games from the English premier league (season 2010-2011) by using two-dimensional player displacement coordinates obtained with a multiple-camera match analysis system provided by STATS (formerly Prozone). Our results show that (i) at micro level the most frequently occurring simplices configuration is 1vs.1 (one attacker vs. one defender); (ii) at meso level, the dynamics of simplices

Predicting soccer matches after unconscious and conscious thought as a function of expertise.

PubMed

Dijksterhuis, Ap; Bos, Maarten W; van der Leij, Andries; van Baaren, Rick B

2009-11-01

In two experiments, we investigated the effects of expertise and mode of thought on the accuracy of people's predictions. Both experts and nonexperts predicted the results of soccer matches after conscious thought, after unconscious thought, or immediately. In Experiment 1, experts who thought unconsciously outperformed participants in all other conditions. Whereas unconscious thinkers showed a correlation between expertise and accuracy of prediction, no such relation was observed for conscious thinkers or for immediate decision makers. In Experiment 2, this general pattern was replicated. In addition, experts who thought unconsciously were better at applying diagnostic information than experts who thought consciously or who decided immediately. The results are consistent with unconscious-thought theory.

Ball-Sport Endurance and Sprint Test (BEAST90): validity and reliability of a 90-minute soccer performance test.

PubMed

Williams, Jeremy D; Abt, Grant; Kilding, Andrew E

2010-12-01

The aim of this study was to determine the validity and reliability of a 90-minute soccer performance test: Ball-sport Endurance and Sprint Test (BEAST90). Fifteen healthy male amateur soccer players participated and attended 5 testing sessions over a 10-day period to perform physiologic and soccer-specific assessments. This included familiarization sessions and 2 full trials of the BEAST90, separated by 7 days. The total 90-minute distance, mean percent peak heart rate (HRpeak), and estimated percent peak oxygen uptake of the BEAST90 were 8,097 ± 458 m, 85 ± 5% and 82 ± 14%, respectively. Measures obtained from trial 1 and trial 2 were not significantly different (p > 0.05). Reliability of measures over 90 minutes ranged from 0.9-25.5% (% typical error). The BEAST90 protocol replicated soccer match play in terms of time, movement patterns, physical demands (volume and intensity), distances, and mean and HRpeak values, as well as having an aerobic load similar to that observed during a soccer match. Reproducibility of key physical measures during the BEAST90 were mostly high, suggesting good reliability. The BEAST90 could be used in studies that wish to determine the effects of training or nutritional interventions on prolonged intermittent physical performance.

The Creative Soccer Platform: New Strategies for Stimulating Creativity in Organized Youth Soccer Practice

ERIC Educational Resources Information Center

Rasmussen, Ludvig Johan Torp; Østergaard, Lars Domino

2016-01-01

Creativity is essential in soccer due to the unpredictable and complex situations occurring in the game, where stereotypical play gradually loses its efficiency. Further, creativity is an important psychological factor for the development of soccer expertise, and valuing creativity increases satisfaction and well-being. Although creative players…

Brief report: Behavioral risk factors for youth soccer (football) injury.

PubMed

Schwebel, David C; Banaszek, Mark M; McDaniel, McCall

2007-05-01

By most reports, soccer (football) is among the most played and most popular sports in the world. This study prospectively examined behavioral risk factors for youth soccer injury. Sixty 11- and 12-year-old boys who played on six teams in a suburban recreational soccer league were followed over the course of a season. Six predictors were assessed prior to the start of the season via self-report measures from coaches, parents, and the players themselves: inhibition, aggression, risk-taking, skill, experience playing soccer, and physical size. All games were videotaped, and tapes were reviewed to record players' collisions with other players, fouls, falls during the course of play, and injuries. Greater skill and less experience playing soccer best predicted injury risk. Inhibition, aggression, and risk-taking did not emerge as predictors. Results are discussed with respect to previous research in youth sport and general pediatric injury risk.

The influence of the playing surface on the exercise intensity of small-sided recreational soccer games.

PubMed

Brito, João; Krustrup, Peter; Rebelo, António

2012-08-01

This study aimed to analyze the influence of the playing surface on movement pattern, physical loading, perceived exertion, and fatigue development during small-sided recreational soccer games. Time-motion, heart rate, blood lactate, and perceived exertion were measured for 16 recreational players aged 22 (range: 19-35) yrs. During 5-a-side soccer games on 3 different field surfaces: sand, artificial turf, and asphalt. Jump and sprint tests were performed prior to and after each game. Total distance covered was higher on asphalt and turf than on sand (3.89±0.04 and 3.73±0.12 vs. 2.59±0.21 km; p<.01), and the number of high-intensity runs was higher on asphalt than on turf (55±3 vs. 43±3; p<.05), but not sand (46±6). Mean heart rate (means±SEM, 160±3 vs. 171±1 b.p.m.) and time>90% HR(max) (20.8±5.1% vs. 44.1±5.0%) were lower (p<.05) on asphalt than on turf, with intermediate values for sand. Blood lactate was lower on asphalt than on sand (2.8±0.3 vs. 4.7±0.6 mmolL(-1); p<.05). Perceived exertion was lower on asphalt than on turf and sand (VAS 0-100: 52±3 vs. 72±3 and 72±3; p<.01). After the game, squat and countermovement jump performances were lower (4.9-8.1%, and 1.9-6.4%, respectively; p<.001) for all field surfaces, but no changes were observed in 5- and 30-m sprint performance. Small-sided recreational soccer games elicit high heart rates, multiple intense actions, and decreased jump performance for all the investigated playing surfaces, suggesting that multiple fitness and health benefits can be achieved through soccer on sand, artificial turf and asphalt. Nonetheless, locomotor activities, heart rate, blood lactate levels, and perceived exertion differ between surfaces. Copyright © 2012 Elsevier B.V. All rights reserved.

Hot and Hypoxic Environments Inhibit Simulated Soccer Performance and Exacerbate Performance Decrements When Combined

PubMed Central

Aldous, Jeffrey W. F.; Chrismas, Bryna C. R.; Akubat, Ibrahim; Dascombe, Ben; Abt, Grant; Taylor, Lee

2016-01-01

The effects of heat and/or hypoxia have been well-documented in match-play data. However, large match-to-match variation for key physical performance measures makes environmental inferences difficult to ascertain from soccer match-play. Therefore, the present study aims to investigate the hot (HOT), hypoxic (HYP), and hot-hypoxic (HH) mediated-decrements during a non-motorized treadmill based soccer-specific simulation. Twelve male University soccer players completed three familiarization sessions and four randomized crossover experimental trials of the intermittent Soccer Performance Test (iSPT) in normoxic-temperate (CON: 18°C 50% rH), HOT (30°C; 50% rH), HYP (1000 m; 18°C 50% rH), and HH (1000 m; 30°C; 50% rH). Physical performance and its performance decrements, body temperatures (rectal, skin, and estimated muscle temperature), heart rate (HR), arterial blood oxygen saturation (SaO2), perceived exertion, thermal sensation (TS), body mass changes, blood lactate, and plasma volume were all measured. Performance decrements were similar in HOT and HYP [Total Distance (−4%), High-speed distance (~−8%), and variable run distance (~−12%) covered] and exacerbated in HH [total distance (−9%), high-speed distance (−15%), and variable run distance (−15%)] compared to CON. Peak sprint speed, was 4% greater in HOT compared with CON and HYP and 7% greater in HH. Sprint distance covered was unchanged (p > 0.05) in HOT and HYP and only decreased in HH (−8%) compared with CON. Body mass (−2%), temperatures (+2–5%), and TS (+18%) were altered in HOT. Furthermore, SaO2 (−8%) and HR (+3%) were changed in HYP. Similar changes in body mass and temperatures, HR, TS, and SaO2 were evident in HH to HOT and HYP, however, blood lactate (p < 0.001) and plasma volume (p < 0.001) were only significantly altered in HH. Perceived exertion was elevated (p < 0.05) by 7% in all conditions compared with CON. Regression analysis identified that absolute TS and absolute

Rates and Determinants of Return to Play After Anterior Cruciate Ligament Reconstruction in National Collegiate Athletic Association Division I Soccer Athletes: A Study of the Southeastern Conference.

PubMed

Howard, Jennifer S; Lembach, Mark L; Metzler, Adam V; Johnson, Darren L

2016-02-01

Factors and details regarding return to play in elite, collegiate female soccer athletes after an anterior cruciate ligament (ACL) injury and reconstruction have not been well studied. To evaluate return to play among collegiate female soccer players, specifically examining the effect of surgical and individual athlete characteristics on the return-to-play rate. Descriptive epidemiology study. Sports medicine and athletic training staff at institutions from the National Collegiate Athletic Association Southeastern Conference (SEC) were contacted to request participation in the study. All institutions were sent a standardized spreadsheet with response choices and instructions regarding athlete inclusion criteria. Athlete, injury, surgical technique, and return-to-play data were requested for ACL reconstructions performed on female soccer athletes at the participating institutions over the previous 8 years. χ(2) analyses were used to compare the return-to-play rate by year in school, scholarship status, position, depth chart status, procedure, graft type, graft fixation, concomitant procedures, and previous ACL injuries. All 14 of the SEC institutions chose to participate and provided data. A total of 80 ACL injuries were reported, with 79 surgical reconstructions and return-to-play data for 78 collegiate soccer athletes. The overall return-to-play rate was 85%. There was a statistical significance in return-to-play rates favoring athletes in earlier years of eligibility versus later years (P < .001). Athletes in eligibility years 4 and 5 combined had a return-to-play rate of only 40%. Scholarship status likewise showed significance (P < .001), demonstrating a higher return-to-play rate for scholarship athletes (91%) versus nonscholarship athletes (46%). No significant differences in return-to-play rates were observed based on surgical factors, including concomitant knee procedures, graft type, and graft fixation method. Collegiate female soccer athletes have a high

Nutritional aspects of women's soccer.

PubMed

Brewer, J

1994-01-01

Female soccer players often have only limited time available to prepare and consume meals, due to the constraints faced by having to combine training and playing with full-time occupations. The energy expenditure of females playing soccer has been estimated at approximately 70% VO2 max, corresponding to an energy production of around 4600 kJ (1100 kcal). As with male soccer players, carbohydrate consumption is essential to support the demands of playing, training and to facilitate recovery. There are some reports to suggest that females in team sports may consume diets with a low energy intake, due to the desire to lose or maintain body weight. In extreme cases, this can result in eating disorders. However, there is no clear evidence to suggest that this problem is common among female soccer players. To maintain a consistent balance between energy intake and expenditure, players should receive nutritional advice to cover all phases of the year, not just the competitive season. Dietary calcium and iron supplements may be a useful precautionary measure, in players who are known to be at risk of deficiencies in these areas. Correct and sensitive nutritional counselling is essential for players and coaches.

Competing with lower level opponents decreases intra-team movement synchronization and time-motion demands during pre-season soccer matches.

PubMed

Folgado, Hugo; Duarte, Ricardo; Fernandes, Orlando; Sampaio, Jaime

2014-01-01

This study aimed to quantify the time-motion demands and intra-team movement synchronization during the pre-season matches of a professional soccer team according to the opposition level. Positional data from 20 players were captured during the first half of six pre-season matches of a Portuguese first league team. Time-motion demands were measured by the total distance covered and distance covered at different speed categories. Intra-team coordination was measured by calculating the relative phase of all pairs of outfield players. Afterwards, the percentage of time spent in the -30° to 30° bin (near-in-phase mode of coordination) was calculated for each dyad as a measure of space-time movement synchronization. Movement synchronization data were analyzed for the whole team, according to each dyad average speed and by groups of similar dyadic synchronization tendencies. Then, these data were compared according to the opponent team level (first league; second league; amateurs). Time-motion demands showed no differences in total distance covered per opposition levels, while matches opposing teams of superior level revealed more distance covered at very high intensity. Competing against superior level teams implied more time in synchronized behavior for the overall displacements and displacements at higher intensities. These findings suggest that playing against higher-level opponents (1st league teams) increased time-motion demands at high intensities in tandem with intra-team movement synchronization tendencies.

Injuries among Spanish male amateur soccer players: a retrospective population study.

PubMed

Herrero, Helena; Salinero, Juan José; Del Coso, Juan

2014-01-01

Soccer is the most popular sport worldwide, with about 265 million players, both professionals and amateurs. Most research investigating soccer injuries has focused on professional players because they have greater exposure time, but most soccer players are at the recreational level. To undertake a retrospective epidemiological study of the injuries sustained in Spanish amateur soccer during the 2010-2011 season. Descriptive epidemiological study. Any injuries incurred by the 134,570 recreational soccer players (aged 18-55 years) registered with the Spanish Football Federation were reported to the federation's medical staff. A standardized medical questionnaire, based on the Fédération International de Football Association (FIFA) Medical and Research Centre (F-MARC) consensus for collection procedures in studies of soccer injuries, was used to classify the injury according to type, severity, location, and treatment. A total of 15,243 injuries were reported, with an average of 0.11 injuries per player and per year. From the total number of injuries, 67.2% were classified as injuries that resulted in time loss, while the remaining 32.7% were injuries that required medical attention. Most injuries led to a minimum of 1 competitive match being missed (87%), and only 2.5% were recurrent injuries. The rate of injuries per 1000 hours of play was double during games (1.15/1000 hours) compared with during training (0.49/1000 hours). From the total number of injuries reported, 7.7% corresponded to goalkeepers, 24.2% to forwards, 33.8% to defenders, and 34.3% to midfielders. The knee (29.9%) and ankle joints (12.4%) were the most common body locations injured, while ligament sprains and ruptures accounted for 32.1% of the total injuries attended. Older amateur players (age ≥30 years) had a greater number of injuries per year and per 1000 hours of play than their younger counterparts. The risk of injury in amateur soccer is lower than that previously reported in

Developing Talented Soccer Players: An Analysis of Socio-Spatial Factors as Possible Key Constraints

PubMed Central

Pastor-Vicedo, Juan C.; González-Víllora, Sixto; Teoldo da Costa, Israel

2016-01-01

Abstract Most studies on the identification and development of soccer talent have been one-dimensional in nature. Although some multi-dimensional analyses have been conducted, few research studies have assessed in any depth the socio-spatial factors influencing talent development. The aim of this particular study was to analyse variations in the international representation of clubs (n = 821) and countries (n = 59) in the development of players who took part in the 2014 FIFA Soccer World Cup. Clubs and countries were ranked and divided into quartiles according to the number of players developed between the ages of 15 and 21 (clubs and countries that developed players for at least three years between these ages) and the number of official league matches played by these players up to the age of 23. Significant variations were observed between clubs in terms of the number of developed players who took part in the World Cup and the number of official league matches played by these players up to the age of 23 (p < .05), and also between countries (p < .05). The findings reveal the need to carry out more in-depth studies into the type of training and competition engaged in by elite players in the period of development between the ages of 15 and 21. It may be the case that these factors are potentially decisive socio-spatial constraints in the development of soccer talent. PMID:28031773

Game Demands of Seven-A-Side Soccer in Young Players.

PubMed

Barbero-Alvarez, José C; Gómez-López, Maite; Castagna, Carlo; Barbero-Alvarez, Verónica; Romero, David V; Blanchfield, Anthony W; Nakamura, Fábio Y

2017-07-01

Barbero-Alvarez, JC, Gómez-López, M, Castagna, C, Barbero-Alvarez, V, Romero, DV, Blanchfield, AW, and Nakamura, FY. Game demands of seven-a-side soccer in young players. J Strength Cond Res 31(7): 1771-1779, 2017-The aim of this study was to examine the activity patterns and physiological demands of 7-a-side youth soccer matches across 2 chronological age categories (U12 and U14). Twenty-two soccer players of a national youth soccer academy were investigated. Players of each age category performed 2 training matches (2 × 25 minutes) and were monitored by global positioning system and heart rate monitor units. Players of both categories covered similar total distance (5,348 ± 307 m), at similar mean heart rate values (86 ± 4% of maximum). However, the number of high-intensity runs (82.5 ± 17.4 vs. 69.7 ± 15.2) and total distance covered during sprints (264 ± 207 vs. 128 ± 74 m) were significantly (p ≤ 0.05) higher in U14 compared with U12. The results suggest a highly demanding nature of 7-a-side soccer for skilled players, with physical maturity possibly influencing the match-related high-intensity performance at these ages.

Is there a relationship between the playing position of soccer players and their food and macronutrient intake?

PubMed

Iglesias-Gutiérrez, Eduardo; García, Angela; García-Zapico, Pedro; Pérez-Landaluce, Javier; Patterson, Angeles M; García-Rovés, Pablo Miguel

2012-04-01

Many authors have proposed the necessity of the design and implementation of dietary and nutrition education programs for soccer players, although little information is available about the determinants of food selection and nutrient intake. The aim of this study was to evaluate the nutritional intake and eating patterns of soccer players according to their playing position in the team. Eighty-seven young male soccer players (aged 16-21 years) were recruited from the junior teams of a Spanish First Division Soccer League Club and divided into 6 positional categories (goalkeepers, full-backs, centre-backs, midfielders, wingers, and forwards). Body composition (height, weight, and body fat), performance in soccer-specific tests (jumping, sprinting, and intermittent endurance), and dietary intake (weighed food intake method) were assessed. A spontaneous higher carbohydrate intake was observed for full-backs, midfielders, and wingers (g·kg(-1) body mass: 4.9 ± 1.0, 4.9 ± 1.3, 4.9 ± 0.8; % of energy intake: 47 ± 5, 46 ± 6, 46 ± 4), compared with goalkeepers and centre-backs (g·kg(-1) of body mass: 3.9 ± 1.0, 4.3 ± 1.1; % of energy intake: 44 ± 3, 42 ± 4). These differences were related to food selection patterns, and a higher contribution to daily energy intake of cereals, derivatives, and potatoes was observed between full-backs compared with goalkeepers and centre-backs (33% vs. 27% and 25%). The magnitude of these differences is limited considering the whole diet, and an inadequate nutrient intake were observed in most individuals of every group. The design and implementation of nutrition intervention programs, taking into consideration positional differences in nutritional intake, would be useful for these players.

Static stretching does not enhance recovery in elite youth soccer players

PubMed Central

Pooley, Sam; Spendiff, Owen; Allen, Matt; Moir, Hannah J

2017-01-01

Background Static stretching (SS) is a recovery intervention used for the reduction of muscle soreness postexercise. The effects of SS on elite young footballers have received little attention, and therefore the aim of this study was to assess the effects of SS on muscle recovery following competitive soccer matches in elite young footballers. Methods Ten male participants (16±1 years) were recruited from an English Premier League professional soccer academy. Using a controlled crossover design, participants followed one of two recovery interventions (SS or passive recovery (PR)) immediately following completion of competitive soccer matches. Muscle oedema, creatine kinase (CK), countermovement jump with arms (CMJA) performance and perceived muscle soreness were assessed before, immediately after and 48 hours postmatch. Results Competitive soccer matches significantly induced muscle damage, with time intervals of perceived soreness and CK showing significant increases (p<0.05), and CMJA showing significant decreases between prematch, postmatch and 48 hours postmatch for both SS and PR (p<0.05). Comparisons of the absolute effects of SS with PR only revealed significant decreases for CK 48 hours postmatch (p<0.05) as a result of SS intervention. Conclusion The current study demonstrated competitive soccer matches induced muscle damage, which may have detrimental effects on future performance within 24–48 hours postmatch. Furthermore, there was limited evidence to suggest SS would assist in the reduction of muscle soreness postexercise. Therefore, it can be argued that SS is not a beneficial recovery option for elite youth soccer players. PMID:28761702

Oxygen cost and physiological responses of recreational badminton match play.

PubMed

Deka, Pallav; Berg, Kris; Harder, Jeanette; Batelaan, Herman; McGRATH, Melanie

2017-06-01

Badminton, as an Olympic sport, is popular worldwide. However, the benefits of recreational badminton match play are not well known. The purpose of the study was to determine the oxygen cost of recreational badminton match play. Heart rate (HR), blood lactate (BL), rating of perceived exertion (RPE), step count and energy expenditure were also assessed. Fourteen male recreational badminton players aged 35.9±6.62 years participated in test sessions to assess oxygen uptake (VO2) and the related physiological responses of match play. During the match play sessions, participants played singles badminton matches for 30 min while wearing a portable metabolic system. VO2 and HR were continuously recorded while blood lactate and RPE were determined following warm-up, at 15 minutes and 30 minutes of match play. Step count was recorded at 15 minutes and 30 minutes of play. VO2 over 30 minutes was 34.4±5.8 mL/kg/min which was 76.1% of maximal oxygen uptake. Across three 10-minute periods of play, VO2 was not significantly different while HR was higher in the third 10-minute period than the first and second 10-minute periods (P=0.001). Mean HR over 30 minutes was 167.9±9.4 bpm. BL was significantly higher at 15 and 30 minutes than following warm-up while RPE of 17.57±1.91 after 30 minutes was significantly higher (P=0.009) than RPE of 15.79±1.63 at 15 minutes. Step count did not vary between the two 15-minute periods of play with a total of 2404±360 steps while energy expenditure over 30 minutes of play was 391.7±66 kcal. Recreational badminton match play can be categorized as vigorous intensity suggesting that it can be a viable means of achieving recommended physical activity and improving aerobic fitness.

Dietary analysis of young professional soccer players for 1 week during the competitive season.

PubMed

Russell, Mark; Pennock, Anthony

2011-07-01

Limited data exist concerning the dietary practices of young professional soccer players that compete within the United Kingdom. Therefore, the purpose of this study was to investigate the nutritional and activity habits of professional male soccer players (n = 10; age: 17 ± 1 years, height: 1.72 ± 0.01 m, mass: 67.5 ± 1.8 kg, estimated maximal aerobic capacity: 57.8 ± 0.9 ml·kg·min) who played for the youth team of a UK-based Championship club. All players recorded their 7-day dietary intake and activity habits during a competitive week that included a match day, 4- training days, and 2 rest days in the first half of the 2009/2010 playing season. The intake of carbohydrates (5.9 ± 0.4 g·kg·d), proteins (1.7 ± 0.1 g·kg·d), and fats (1.5 ± 0.1 g·kg·d) represented 56 ± 1, 16 ± 1, and 31 ± 1% of the mean daily energy intake respectively. The intake of fiber was found to be significantly lower than Recommended Nutrient Intake (RNI) values (67% of RNI, p < 0.001), whereas all other analyzed micronutrients met or exceeded recommended values. A mean daily energy deficit of 788 ± 174 kcal existed because daily energy expenditures exceeded that of intake (3,618 ± 61 vs. 2831 ± 164 kcal, p = 0.001). The mean daily fluid intake was 3.2 ± 0.3 L. Consequently, the nutritional practices of the sampled group of professional youth soccer players were inadequate to sustain optimized performance throughout training and match play. Youth soccer players should therefore seek to ensure that their diets contain adequate energy through increased total caloric intake, while also optimizing the proportion of energy derived from carbohydrates and ensuring that enough fiber-rich foods are consumed.

Shoe and Field Surface Risk Factors for Acute Lower Extremity Injuries Among Female Youth Soccer Players.

PubMed

OʼKane, John W; Gray, Kristen E; Levy, Marni R; Neradilek, Moni; Tencer, Allan F; Polissar, Nayak L; Schiff, Melissa A

2016-05-01

To describe acute lower extremity injuries and evaluate extrinsic risk factors in female youth soccer. Nested case-control study. Youth soccer clubs in Seattle, WA. Female soccer players (n = 351) ages 11 to 15 years randomly selected from 4 soccer clubs from which 83% of their players were enrolled with complete follow-up for 92% of players. Injured players were interviewed regarding injury, field surface, shoe type, and position. Uninjured controls, matched on game or practice session, were also interviewed. The association between risk factors and acute lower extremity injury using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). One hundred seventy-three acute lower extremity injuries occurred involving primarily the ankle (39.3%), knee (24.9%), and thigh (11.0%). Over half (52.9%) recovered within 1 week, whereas 30.2% lasted beyond 2 weeks. During practices, those injured were approximately 3-fold (OR, 2.83; 95% CI, 1.49-5.31) more likely to play on grass than artificial turf and 2.4-fold (95% CI, 1.03-5.96) more likely to wear cleats on grass than other shoe and surface combinations. During games, injured players were 89% (95% CI, 1.03-4.17) more likely to play defender compared with forward. Half of the acute lower extremity injuries affected the ankle or knee. Grass surface and wearing cleats on grass increased training injuries. The majority, 64%, of female youth soccer players' acute injuries involve the ankle and knee and injury prevention strategies in this age group should target these areas. When considering playing surfaces for training, communities and soccer organizations should consider the third-generation artificial turf a safe alternative to grass.

Importance of Speed and Power in Elite Youth Soccer Depends on Maturation Status.

PubMed

Murtagh, Conall F; Brownlee, Thomas E; OʼBoyle, Andrew; Morgans, Ryland; Drust, Barry; Erskine, Robert M

2018-02-01

Murtagh, CF, Brownlee, TE, O'Boyle, A, Morgans, R, Drust, B, and Erskine, RM. Importance of speed and power in elite youth soccer depends on maturation status. J Strength Cond Res 32(2): 297-303, 2018-Maturation status is a confounding factor when identifying talent in elite youth soccer players (ESP). By comparing performance of ESP and control participants (CON) matched for maturation status, the aims of our study were to establish the importance of acceleration, sprint, horizontal-forward jump, and vertical jump capabilities for determining elite soccer playing status at different stages of maturation. Elite youth soccer players (n = 213; age, 14.0 ± 3.5 years) and CON (n = 113; age, 15.0 ± 4.4 years) were grouped using years from/to predicted peak height velocity (PHV) to determine maturation status (ESP: pre-PHV, n = 100; mid-PHV, n = 25; post-PHV, n = 88; CON: pre-PHV, n = 44; mid-PHV, n = 15; post-PHV, n = 54). Participants performed 3 reps of 10- and 20-m sprint, bilateral vertical countermovement jump (BV CMJ), and bilateral horizontal-forward CMJ (BH CMJ). Elite youth soccer players demonstrated faster 10-m (p < 0.001) and 20-m sprint (p < 0.001) performance than CON at all stages of maturation. Mid-PHV and post-PHV ESP achieved greater BV CMJ height (p < 0.001) and BH CMJ distance (ESP vs. CON; mid-PHV: 164.32 ± 12.75 vs. 136.53 ± 21.96 cm; post-PHV: 197.57 ± 17.05 vs. 168.06 ± 18.50 cm; p < 0.001) compared with CON, but there was no difference in BV or BH CMJ between pre-PHV ESP and CON. Although 10 and 20 m and sprint performance may be determinants of elite soccer playing status at all stages of maturation, horizontal-forward and vertical jumping capabilities only discriminate ESP from CON participants at mid- and post-PHV. Our data therefore suggest that soccer talent identification protocols should include sprint, but not jump assessments in pre-PHV players.

Stress, Sleep and Recovery in Elite Soccer: A Critical Review of the Literature.

PubMed

Nédélec, Mathieu; Halson, Shona; Abaidia, Abd-Elbasset; Ahmaidi, Said; Dupont, Gregory

2015-10-01

In elite soccer, players are frequently exposed to various situations and conditions that can interfere with sleep, potentially leading to sleep deprivation. This article provides a comprehensive and critical review of the current available literature regarding the potential acute and chronic stressors (i.e., psychological, sociological and physiological stressors) placed on elite soccer players that may result in compromised sleep quantity and/or quality. Sleep is an essential part of the recovery process as it provides a number of important psychological and physiological functions. The effects of sleep disturbance on post-soccer match fatigue mechanisms and recovery time course are also described. Physiological and cognitive changes that occur when competing at night are often not conducive to sleep induction. Although the influence of high-intensity exercise performed during the night on subsequent sleep is still debated, environmental conditions (e.g., bright light in the stadium, light emanated from the screens) and behaviours related to evening soccer matches (e.g., napping, caffeine consumption, alcohol consumption) as well as engagement and arousal induced by the match may all potentially affect subsequent sleep. Apart from night soccer matches, soccer players are subjected to inconsistency in match schedules, unique team schedules and travel fatigue that may also contribute to the sleep debt. Sleep deprivation may be detrimental to the outcome of the recovery process after a match, resulting in impaired muscle glycogen repletion, impaired muscle damage repair, alterations in cognitive function and an increase in mental fatigue. The role of sleep in recovery is a complex issue, reinforcing the need for future research to estimate the quantitative and qualitative importance of sleep and to identify influencing factors. Efficient and individualised solutions are likely needed.

Soccer Injury Movement Screen (SIMS) Composite Score Is Not Associated With Injury Among Semi-Professional Soccer Players.

PubMed

McCunn, Robert; Fünten, Karen Aus der; Whalan, Matthew; Sampson, John A; Meyer, Tim

2018-05-08

Study Design Prospective cohort. Background The association between movement quality and injury is equivocal. No soccer-specific movement assessment has been prospectively investigated in relation to injury risk. Objectives To investigate the association between a soccer-specific movement quality assessment and injury risk among semi-professional soccer players. Methods Semi-professional soccer players (n=306) from 12 clubs completed the Soccer Injury Movement Screen (SIMS) during the pre-season period. Individual training/match exposure and non-contact time loss injuries were recorded prospectively for the entirety of the 2016 season. Relative risks (RR) were calculated, and presented with 90% confidence intervals (CI), for the SIMS composite and individual sub-test scores from generalized linear models with Poisson distribution offset for exposure. Results When considering non-contact time loss lower extremity injuries (primary level of analysis), there was a most likely trivial association with the SIMS composite score. Similarly, SIMS composite score demonstrated most likely to likely trivial associations to all injury categories included in the secondary level of analysis (non-contact time loss hip/groin, thigh, knee and ankle injuries). When considering hamstring strains and ankle sprains specifically (tertiary level of analysis) the SIMS composite score, again, demonstrated very likely trivial associations. A total of 262 non-contact time loss injuries were recorded. The overall (training and match exposure combined) incidence of non-contact time loss injury was 12/1000 hours. Conclusion The SIMS composite score demonstrated no association to any of the investigated categories of soccer-related injury. The SIMS composite score should not be used to group players into 'high' or 'low' risk groups. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther, Epub 8 May 2018. doi:10.2519/jospt.2018.8037.

Activity profiles in U17, U20 and senior women's Brazilian National soccer teams during international competitions: Are there meaningful differences?

PubMed

Ramos, Guilherme P; Nakamura, Fábio Y; Penna, Eduardo M; Wilke, Carolina Franco; Pereira, Lucas A; Loturco, Irineu; Capelli, Luciano; Mahseredjian, Fábio; Silami-Garcia, Emerson; Coimbra, Cândido C

2017-07-31

The aim of this study was to compare locomotor activity profiles of Brazilian top-class female soccer players competing at distinct age brackets (U17, U20, and Senior). External match load of 14 U17, 14 U20, and 17 Senior female soccer players competing in 6-7 full official international matches were assessed using global positioning systems (GPS). Total distance covered, distance covered in high intensity (HID:15.6-20 kmh), distance covered in sprints (sprint:>20 kmh), number of accelerations (Acc)>1 ms, decelerations (Dec) >-1 ms, and Player Load generally increased across the age brackets (U17playing positions, Senior athletes presented greater total distance, accelerations, and decelerations than U20 players. For high-intensity distance and sprints, only central defender and midfielder senior players presented greater values than U20 players. Senior players demonstrated higher values in all locomotor activities in comparison to U17 players, irrespective of playing positions. Except for central defenders that presented similar total distance, sprint distance, and number of accelerations between U20 and U17, the majority of match external loads evaluated in all playing positions were greater in U20 than in U17 players. These results provide useful information for player development and should be used to establish appropriate match-specific conditioning drills according to age categories.

Carbohydrate ingestion improves performance of a new reliable test of soccer performance.

PubMed

Currell, Kevin; Conway, Steve; Jeukendrup, Asker E

2009-02-01

The aim of the study was to investigate the reliability of a new test of soccer performance and evaluate the effect of carbohydrate (CHO) on soccer performance. Eleven university footballers were recruited and underwent 3 trials in a randomized order. Two of the trials involved ingesting a placebo beverage, and the other, a 7.5% maltodextrin solution. The protocol comprised a series of ten 6-min exercise blocks on an outdoor Astroturf pitch, separated by the performance of 2 of the 4 soccer-specific tests, making the protocol 90 min in duration. The intensity of the exercise was designed to be similar to the typical activity pattern during soccer match play. Participants performed skill tests of dribbling, agility, heading, and shooting throughout the protocol. The coefficients of variation for dribbling, agility, heading, and shooting were 2.2%, 1.2%, 7.0%, and 2.8%, respectively. The mean combined placebo scores were 42.4 +/- 2.7 s, 43.1 +/- 3.7 s, 210 +/- 34 cm, and 212 +/- 17 points for agility, dribbling, heading, and kicking, respectively. CHO ingestion led to a combined agility time of 41.5 +/- 0.8 s, for dribbling 41.7 +/- 3.5 s, 213 +/- 11 cm for heading, and 220 +/- 5 points for kicking accuracy. There was a significant improvement in performance for dribbling, agility, and shooting (p < .05) when CHO was ingested compared with placebo. In conclusion, the protocol is a reliable test of soccer performance, and ingesting CHO leads to an improvement in soccer performance.

Groin pain and soccer players: male versus female occurrence.

PubMed

Karlsson, M K; Dahan, R; Magnusson, H; Nyquist, F; Rosengren, B E

2014-08-01

Groin pain is common in soccer players. Comparison of results from different studies, especially between genders, is difficult as studies use different definitions and data collection procedures. Therefore we conducted a study of both male and female soccer players enabling direct gender comparison. The study enrolled 479 male soccer players aged 25 years (17-43) (mean with range) and 144 female soccer players aged 23 years (16-47), who answered a mailed questionnaire that included specific questions on groin pain and sports history. Data are presented as proportions (%) or as mean with 95% confidence intervals (95% CI). Groin pain was experienced by 55% of male soccer players and 28% of female soccer players, resulting in an odds ratio (OR) of 2.9 (95% CI 1.9, 4.5). Groin pain occurred more often in the preseason, than during the rest of the season in both male and female players (both P<0.001). Playing position in the team or playing league did not seem to influence the risk of suffering groin pain. In soccer players, male gender and preseasonal training appear to be risk factors for developing groin pain.

A comparison of the physiological profiles of elite Gaelic footballers, hurlers, and soccer players

PubMed Central

McIntyre, M

2005-01-01

Background: Gaelic football, soccer, and hurling are prominent field games in Ireland and involve participants undertaking a variety of playing tasks and skills which place various physiological demands on the participants. The aim of this study was to evaluate and compare the mid-season physiological profiles of elite players. Methods: Physiological assessment was carried out on 29 inter-county Gaelic footballers, 30 inter-county hurlers, and 21 League of Ireland soccer players. Results: Significant differences were reported for % body fat (p<0.05), aerobic capacity (p<0.05), flexibility (p<0.05), upper body strength (p<0.05), upper body strength endurance (p<0.05), abdominal endurance (p<0.05), and speed endurance (p<0.05), while there were no differences recorded for height, weight, or speed levels. A relatively heterogeneous body size is evident for all three sports. Soccer players had lower body fat levels, greater aerobic capacity, greater strength endurance, and greater flexibility compared to both Gaelic footballers and hurlers, possibly due to specific training and conditioning programmes or physical adaptation to match play The greater strength of both Gaelic footballers and hurlers and the superior speed endurance levels of Gaelic footballers also reflect the physical nature of the sports. Similar speed levels amongst all three sports reflect the importance of speed for performance. Conclusions: The various physiological attributes for Gaelic football, soccer, and hurling reflect the physical requirements for success and participation in each of these field games. PMID:15976166

Home advantage in Turkish professional soccer.

PubMed

Seçkin, Aylin; Pollard, Richard

2008-08-01

Home advantage is known to play an important role in the outcome of professional soccer games and to vary considerably worldwide. In the Turkish Super League over the last 12 years, 61.5% of the total points gained have been won by the home team, a figure similar to the worldwide average and to the Premier League in England. It is lower (57.7%) for games played between teams from Istanbul and especially high for games involving teams from cities in the more remote and ethnically distinct parts of Turkey (Van and Diyarbakir). Match performance data show that although home teams in Turkey take 26% more shots at goal than away teams, the success rates for shots do not differ. For fouls and disciplinary cards, home and away teams do not differ significantly in Turkey, a finding that differs from games in England, perhaps due to less referee bias.

Colonic transit in soccer players.

PubMed

Sesboüé, B; Arhan, P; Devroede, G; Lecointe-Besançon, I; Congard, P; Bouchoucha, M; Fabre, J

1995-04-01

To evaluate the effects of exercise on colonic function, we measured total and segmental transit times in 11 male soccer players and nine male radiology student technicians. Diet was kept constant in all subjects, who maintained their normal activities. For the soccer players, normal activities included 15 h of training and one match each week. Transit times were measured with radioopaque markers, using the multiple-ingestion, single-radiograph technique. No overall difference in large bowel transit was observed between the two groups. Right colon transit was considerably slower in the soccer players, whereas left colon and rectal transit were slightly accelerated. We conclude that an intensive sport activity only modifies regional differences in large bowel function. This may be of importance in extreme conditions, such as those experienced by marathon runners. Data should be obtained before prescribing exercise to treat constipation.

Applied physiology of female soccer: an update.

PubMed

Datson, Naomi; Hulton, Andrew; Andersson, Helena; Lewis, Tracy; Weston, Matthew; Drust, Barry; Gregson, Warren

2014-09-01

The popularity and professionalism of female soccer has increased markedly in recent years, with elite players now employed on either a professional or semi-professional basis. The previous review of the physiological demands of female soccer was undertaken two decades ago when the sport was in its relative infancy. Increased research coupled with greater training and competition demands warrants an updated review to consider the effect on physical performance and injury patterns. The physical demands of match-play along with the influence of factors such as the standard of competition, playing position and fatigue have been explored. Total distance covered for elite female players is approximately 10 km, with 1.7 km completed at high speed (>15 kmh(-1)) [corrected].Elite players complete 28% more high-speed running and 24 % more sprinting than moderate-level players. Decrements in high-speed running distance have been reported between and within halves, which may indicate an inability to maintain high-intensity activity. Although the physical capacity of female players is the most thoroughly researched area, comparisons are difficult due to differing protocols. Elite players exhibit maximal oxygen uptake (VO2max) values of 49.4-57.6 mL·kg(-1)·min(-1), Yo Yo Intermittent Endurance test level 2 (YYIE2) scores of 1,774 ± 532 m [mean ± standard deviation (SD)] and 20 m sprint times of 3.17 ± 0.03 s (mean ± SD). Reasons for the increased prevalence of anterior cruciate ligament injuries in females (2-6 times greater than males) are discussed, with anatomical, biomechanical loading and neuromuscular activation differences being cited in the literature. This review presents an in-depth contemporary examination of the applied physiology of the female soccer player.

High injury incidence in adolescent female soccer.

PubMed

Clausen, Mikkel Bek; Zebis, Mette Kreutzfeldt; Møller, Merete; Krustrup, Peter; Hölmich, Per; Wedderkopp, Niels; Andersen, Lars Louis; Christensen, Karl Bang; Thorborg, Kristian

2014-10-01

Previous studies report varying rates of time-loss injuries in adolescent female soccer, ranging from 2.4 to 5.3 per 1000 athlete-exposures or 2.5 to 3.7 per 1000 hours of exposure. However, these studies collected data using traditional injury reports from coaches or medical staff, with methods that significantly underestimate injury rates compared with players' self-reports. The primary aim was to investigate the injury incidence in adolescent female soccer using self-reports via mobile telephone text messaging. The secondary aim was to explore the association between soccer exposure, playing level, and injury risk. Descriptive epidemiology study and cohort study; Level of evidence, 2 and 3. During a full adolescent female soccer season in Denmark (February-June 2012), a population-based sample of 498 girls aged 15 to 18 years was included in the prospective registration of injuries. All players were enrolled on a team participating in Danish Football Association series. Soccer injuries and exposure were reported weekly by answers to standardized text message questions, followed by individual injury interviews. Soccer exposure and playing levels were chosen a priori as the only independent variables of interest in the risk factor analyses. Injury rates and relative risks were estimated using Poisson regression. Generalized estimation equations were used to take into account that players were clustered within teams. There were 498 players who sustained a total of 424 soccer injuries. The incidence of injuries was 15.3 (95% CI, 13.1-17.8), the incidence of time-loss injuries was 9.7 (95% CI, 8.2-11.4), and the incidence of severe injuries was 1.1 (95% CI, 0.7-1.6) per 1000 hours of soccer exposure. Higher average exposure in injury-free weeks was associated with a lower injury risk (P value for trend <.001), and players with low exposure (≤1 h/wk) were 3 to 10 times more likely to sustain a time-loss injury compared with other players (P < .01). Playing level was

Metabolic power demands of rugby league match play.

PubMed

Kempton, Tom; Sirotic, Anita Claire; Rampinini, Ermanno; Coutts, Aaron James

2015-01-01

To describe the metabolic demands of rugby league match play for positional groups and compare match distances obtained from high-speed-running classifications with those derived from high metabolic power. Global positioning system (GPS) data were collected from 25 players from a team competing in the National Rugby League competition over 39 matches. Players were classified into positional groups (adjustables, outside backs, hit-up forwards, and wide-running forwards). The GPS devices provided instantaneous raw velocity data at 5 Hz, which were exported to a customized spreadsheet. The spreadsheet provided calculations for speed-based distances (eg, total distance; high-speed running, >14.4 km/h; and very-high-speed running, >18.1 km/h) and metabolic-power variables (eg, energy expenditure; average metabolic power; and high-power distance, >20 W/kg). The data show that speed-based distances and metabolic power varied between positional groups, although this was largely related to differences in time spent on field. The distance covered at high running speed was lower than that obtained from high-power thresholds for all positional groups; however, the difference between the 2 methods was greatest for hit-up forwards and adjustables. Positional differences existed for all metabolic parameters, although these are at least partially related to time spent on the field. Higher-speed running may underestimate the demands of match play when compared with high-power distance-although the degree of difference between the measures varied by position. The analysis of metabolic power may complement traditional speed-based classifications and improve our understanding of the demands of rugby league match play.

Fly-through viewpoint video system for multi-view soccer movie using viewpoint interpolation

NASA Astrophysics Data System (ADS)

Inamoto, Naho; Saito, Hideo

2003-06-01

This paper presents a novel method for virtual view generation that allows viewers to fly through in a real soccer scene. A soccer match is captured by multiple cameras at a stadium and images of arbitrary viewpoints are synthesized by view-interpolation of two real camera images near the given viewpoint. In the proposed method, cameras do not need to be strongly calibrated, but epipolar geometry between the cameras is sufficient for the view-interpolation. Therefore, it can easily be applied to a dynamic event even in a large space, because the efforts for camera calibration can be reduced. A soccer scene is classified into several regions and virtual view images are generated based on the epipolar geometry in each region. Superimposition of the images completes virtual views for the whole soccer scene. An application for fly-through observation of a soccer match is introduced as well as the algorithm of the view-synthesis and experimental results..

Phases of match-play in professional Australian Football: Descriptive analysis and reliability assessment.

PubMed

Rennie, Michael J; Watsford, Mark L; Spurrs, Robert W; Kelly, Stephen J; Pine, Matthew J

2018-06-01

To examine the frequency and time spent in the phases of Australian Football (AF) match-play and to assess the intra-assessor reliability of coding these phases of match-play. Observational, intra-reliability assessment. Video footage of 10 random quarters of AF match-play were coded by a single researcher. Phases of offence, defence, contested play, umpire stoppage, set shot and goal reset were coded using a set of operational definitions. Descriptive statistics were provided for all phases of match-play. Following a 6-month washout period, intra-coder reliability was assessed using typical error of measurement (TEM) and intra-class correlation coefficients (ICC). A quarter of AF match-play involved 128±20 different phases of match-play. The highest proportion of match-play involved contested play (25%), followed by offence (18%), defence (18%) and umpire stoppages (18%). The mean duration of offence, defence, contested play, umpire stoppage, set shot and goal reset were 14, 14, 10, 11, 28 and 47s, respectively. No differences were found between the two coding assessments (p>0.05). ICCs for coding the phases of play demonstrated very high reliability (r=0.902-0.992). TEM of the total time spent in each phase of play represented moderate to good reliability (TEM=1.8-9.3%). Coding of offence, defence and contested play tended to display slightly poorer TEMs than umpire stoppages, set shots and goal resets (TEM=8.1 vs 4.5%). Researchers can reliably code the phases of AF match-play which may permit the analysis of specific elements of competition. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research

PubMed Central

Harper, Liam D.; Fothergill, Melissa; West, Daniel J.; Stevenson, Emma; Russell, Mark

2016-01-01

Qualitative research investigating soccer practitioners’ perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: ‘importance of extra-time’, ‘rule changes’, ‘efficacy of extra-time hydro-nutritional provision’, ‘nutritional timing’, ‘future research directions’, ‘preparatory modulations’ and ‘recovery’. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses

Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research.

PubMed

Harper, Liam D; Fothergill, Melissa; West, Daniel J; Stevenson, Emma; Russell, Mark

2016-01-01

Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery

Soft-assembled Multilevel Dynamics of Tactical Behaviors in Soccer

PubMed Central

Ric, Angel; Torrents, Carlota; Gonçalves, Bruno; Sampaio, Jaime; Hristovski, Robert

2016-01-01

This study aimed to identify the tactical patterns and the timescales of variables during a soccer match, allowing understanding the multilevel organization of tactical behaviors, and to determine the similarity of patterns performed by different groups of teammates during the first and second halves. Positional data from 20 professional male soccer players from the same team were collected using high frequency global positioning systems (5 Hz). Twenty-nine categories of tactical behaviors were determined from eight positioning-derived variables creating multivariate binary (Boolean) time-series matrices. Hierarchical principal component analysis (PCA) was used to identify the multilevel structure of tactical behaviors. The sequential reduction of each set level of principal components revealed a sole principal component as the slowest collective variable, forming the global basin of attraction of tactical patterns during each half of the match. In addition, the mean dwell time of each positioning-derived variable helped to understand the multilevel organization of collective tactical behavior during a soccer match. This approach warrants further investigations to analyze the influence of task constraints on the emergence of tactical behavior. Furthermore, PCA can help coaches to design representative training tasks according to those tactical patterns captured during match competitions and to compare them depending on situational variables. PMID:27761120

The relationship between movement speed and duration during soccer matches.

PubMed

Roecker, Kai; Mahler, Hubert; Heyde, Christian; Röll, Mareike; Gollhofer, Albert

2017-01-01

The relationship between the time duration of movement (t(dur)) and related maximum possible power output has been studied and modeled under many conditions. Inspired by the so-called power profiles known for discontinuous endurance sports like cycling, and the critical power concept of Monod and Scherrer, the aim of this study was to evaluate the numerical characteristics of the function between maximum horizontal movement velocity (HSpeed) and t(dur) in soccer. To evaluate this relationship, GPS data from 38 healthy soccer players and 82 game participations (≥30 min active playtime) were used to select maximum HSpeed for 21 distinct t(dur) values (between 0.3 s and 2,700 s) based on moving medians with an incremental t(dur) window-size. As a result, the relationship between HSpeed and Log(t(dur)) appeared reproducibly as a sigmoidal decay function, and could be fitted to a five-parameter equation with upper and lower asymptotes, and an inflection point, power and decrease rate. Thus, the first three parameters described individual characteristics if evaluated using mixed-model analysis. This study shows for the first time the general numerical relationship between t(dur) and HSpeed in soccer games. In contrast to former descriptions that have evaluated speed against power, HSpeed against t(dur) always yields a sigmoidal shape with a new upper asymptote. The evaluated curve fit potentially describes the maximum moving speed of individual players during the game, and allows for concise interpretations of the functional state of team sports athletes.

The relationship between movement speed and duration during soccer matches

PubMed Central

Mahler, Hubert; Heyde, Christian; Röll, Mareike; Gollhofer, Albert

2017-01-01

The relationship between the time duration of movement (t(dur)) and related maximum possible power output has been studied and modeled under many conditions. Inspired by the so-called power profiles known for discontinuous endurance sports like cycling, and the critical power concept of Monod and Scherrer, the aim of this study was to evaluate the numerical characteristics of the function between maximum horizontal movement velocity (HSpeed) and t(dur) in soccer. To evaluate this relationship, GPS data from 38 healthy soccer players and 82 game participations (≥30 min active playtime) were used to select maximum HSpeed for 21 distinct t(dur) values (between 0.3 s and 2,700 s) based on moving medians with an incremental t(dur) window-size. As a result, the relationship between HSpeed and Log(t(dur)) appeared reproducibly as a sigmoidal decay function, and could be fitted to a five-parameter equation with upper and lower asymptotes, and an inflection point, power and decrease rate. Thus, the first three parameters described individual characteristics if evaluated using mixed-model analysis. This study shows for the first time the general numerical relationship between t(dur) and HSpeed in soccer games. In contrast to former descriptions that have evaluated speed against power, HSpeed against t(dur) always yields a sigmoidal shape with a new upper asymptote. The evaluated curve fit potentially describes the maximum moving speed of individual players during the game, and allows for concise interpretations of the functional state of team sports athletes. PMID:28742832

Head Impact Biomechanics in Women's College Soccer.

PubMed

Lynall, Robert C; Clark, Michael D; Grand, Erin E; Stucker, Jaclyn C; Littleton, Ashley C; Aguilar, Alain J; Petschauer, Meredith A; Teel, Elizabeth F; Mihalik, Jason P

2016-09-01

There are limited nonlaboratory soccer head impact biomechanics data. This is surprising given soccer's global popularity. Epidemiological data suggest that female college soccer players are at a greater concussion injury risk than their male counterparts. Therefore, the purposes of our study were to quantify head impact frequency and magnitude during women's soccer practices and games in the National Collegiate Athletic Association and to characterize these data across event type, playing position, year on the team, and segment of game (first and second halves). Head impact biomechanics were collected from female college soccer players (n = 22; mean ± SD age = 19.1 ± 0.1 yr, height = 168.0 ± 3.5 cm, mass = 63.7 ± 6.0 kg). We employed a helmetless head impact measurement device (X2 Biosystems xPatch) before each competition and practice across a single season. Peak linear and rotational accelerations were categorized based on impact magnitude and subsequently analyzed using appropriate nonparametric analyses. Overall, women's college soccer players experience approximately seven impacts per 90 min of game play. The overwhelming majority (~90%) of all head impacts were categorized into our mildest linear acceleration impact classification (10g-20g). Interestingly, a higher percentage of practice impacts in the 20g-40g range compared with games (11% vs 7%) was observed. Head impact biomechanics studies have provided valuable insights into understanding collision sports and for informing evidence-based rule and policy changes. These have included changing the football kickoff, ice hockey body checking ages, and head-to-head hits in both sports. Given soccer's global popularity, and the growing public concern for the potential long-term neurological implications of collision and contact sports, studying soccer has the potential to impact many athletes and the sports medicine professionals caring for them.

Concussion among female middle-school soccer players.

PubMed

O'Kane, John W; Spieker, Amy; Levy, Marni R; Neradilek, Moni; Polissar, Nayak L; Schiff, Melissa A

2014-03-01

Despite recent increased awareness about sports concussions, little research has evaluated concussions among middle-school athletes. To evaluate the frequency and duration of concussions in female youth soccer players and to determine if concussions result in stopping play and seeking medical care. Prospective cohort study from March 2008 through May 2012 among 4 soccer clubs from the Puget Sound region of Washington State, involving 351 elite female soccer players, aged 11 to 14 years, from 33 randomly selected youth soccer teams. Of the players contacted, 83.1% participated and 92.4% completed the study. Concussion cumulative incidence, incidence rate, and description of the number, type, and duration of symptoms. We inquired weekly about concussion symptoms and, if present, the symptom type and duration, the event resulting in symptom onset, and whether the player sought medical attention or played while symptomatic. Among the 351 soccer players, there were 59 concussions with 43 742 athletic exposure hours. Cumulative concussion incidence was 13.0% per season, and the incidence rate was 1.2 per 1000 athletic exposure hours (95% CI, 0.9-1.6). Symptoms lasted a median of 4.0 days (mean, 9.4 days). Heading the ball accounted for 30.5% of concussions. Players with the following symptoms had a longer recover time than players without these symptoms: light sensitivity (16.0 vs 3.0 days, P = .001), emotional lability (15.0 vs 3.5 days, P = .002), noise sensitivity (12.0 vs 3.0 days, P = .004), memory loss (9.0 vs 4.0 days, P = .04), nausea (9.0 vs 3.0 days, P = .02), and concentration problems (7.0 vs 2.0 days, P = .02). Most players (58.6%) continued to play with symptoms, with almost half (44.1%) seeking medical attention. Concussion rates in young female soccer players are greater than those reported in older age groups, and most of those concussed report playing with symptoms. Heading the ball is a frequent precipitating event. Awareness

The Physical and Athletic Performance Characteristics of Division I Collegiate Female Soccer Players by Position.

PubMed

Lockie, Robert G; Moreno, Matthew R; Lazar, Adrina; Orjalo, Ashley J; Giuliano, Dominic V; Risso, Fabrice G; Davis, DeShaun L; Crelling, Jeff B; Lockwood, John R; Jalilvand, Farzad

2018-02-01

Lockie, RG, Moreno, MR, Lazar, A, Orjalo, AJ, Giuliano, DV, Risso, FG, Davis, DL, Crelling, JB, Lockwood, JR, and Jalilvand, F. The physical and athletic performance characteristics of Division I collegiate female soccer players by position. J Strength Cond Res 32(2): 334-343, 2018-Playing positions in soccer can exhibit different movement demands during a match, contributing to variations in physical and performance characteristics. National Collegiate Athletic Association (NCAA) soccer features different substitution rules when compared to FIFA-sanctioned matches, which could influence each players' characteristics. Therefore, this study determined the athletic performance characteristics of Division I female soccer players. Twenty-six players (3 goalkeepers; 8 defenders; 10 midfielders; 5 forwards) from the same squad completed assessments of: lower-body power (vertical and standing broad jump); linear (0-5, 0-10, 0-30 meter [m] sprint intervals) and change-of-direction (pro-agility shuttle; arrowhead change-of-direction speed test) speed; and soccer-specific fitness (Yo-Yo Intermittent Recovery Test [YYIRT] levels 1 and 2). Players were split into position groups, and a Kruskal-Wallis H test with post hoc pairwise analyses (p ≤ 0.05) calculated significant between-group differences. There were no differences in age, height, or body mass between the positions. Midfielders had a faster 0-5 m time compared with the defenders (p = 0.017) and the goalkeepers (p = 0.030). The defenders (p = 0.011) and midfielders (p = 0.013) covered a greater YYIRT2 distance compared with the goalkeepers. There were no other significant between-position differences. Overall, Division I collegiate female players from the same squad demonstrated similar characteristics as measured by soccer-specific performance tests, which could allow for flexibility in position assignments. However, a relatively homogenous squad could also indicate commonality in training prescription, particularly

Influence of ball type on home advantage in French professional soccer.

PubMed

Dosseville, Fabrice E M

2007-04-01

The home advantage has been consistently found in soccer matches, but conclusive evidence of the origin of this home advantage has yet to be identified. One factor often thought to contribute is familiarity with a local facility. The present study examined home advantage in the French professional soccer male championships (20 teams in each Ligue 1 and 2) and explored the influence of soccer ball type on this phenomenon. Whether it is knowing how a soccer ball rolls on a particular grass surface or some other aspect, the home team can react to the situation better if they know from experience what is likely to happen. The results suggest that type of soccer ball may have an influence on home advantage. Confounding factors are discussed.

Vuvuzela media coverage during the 2010 FIFA soccer world cup tournament: impact on raising awareness of noise-induced hearing loss.

PubMed

Ramma, Lebogang

2011-01-01

Hearing loss, most specifically noise-induced hearing loss (NIHL) due to exposure to vuvuzela noise, received extended media coverage before and during the 2010 Federation Internationale de Football Association (FIFA) soccer world cup tournament. This study aimed to evaluate the impact that this media coverage had on raising awareness about NIHL due to exposure to vuvuzela noise at soccer matches among South African soccer spectators. A descriptive survey study, using a 24-item, self-administered questionnaire was used for this study. One hundred and forty seven (147) soccer spectators were surveyed before (N1 =73) and after (N2 =74) the tournament. Systematic sampling strategy was used to select the participants. Participants completed the questionnaire before the start of matches. Sixteen percent of the participants surveyed reported having had some media exposure about NIHL due to exposure to vuvuzela noise during soccer matches before the tournament in comparison to 26% of the participants after the tournament. This increase in the level of awareness was not statistically significant. Further, most participants were still not aware of the risk of NIHL to them from exposure to excessive noise during matches and did not consider hearing loss from noise exposure during soccer matches a serious concern both before and after the tournament. The results of this study therefore seem to suggest that vuvuzela media coverage during the 2010 FIFA soccer world cup tournament did not significantly raise the level of awareness about NIHL due to exposure to excessive noise during matches among the spectators surveyed.

Shoe and field surface risk factors for acute lower extremity injuries among female youth soccer players

PubMed Central

O'Kane, John W.; Gray, Kristen E.; Levy, Marni R.; Neradilek, Moni; Tencer, Allan F.; Polissar, Nayak L.; Schiff, Melissa A.

2015-01-01

Objective Describe acute lower extremity injuries and evaluate extrinsic risk factors in female youth soccer Design Nested case-control study Setting Youth soccer clubs in Washington State, USA. Participants Female soccer players (N= 351) ages 11 to 15 years randomly selected from 4 soccer clubs from which 83% of their players were enrolled with complete follow-up for 92% of players. Interventions Injured players were interviewed regarding injury, field surface, shoe type, and position. Uninjured controls, matched on game or practice session, were also interviewed. Main Outcome Measures The association between risk factors and acute lower extremity injury using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). Results One hundred seventy-three acute lower extremity injuries occurred involving primarily the ankle (39.3%), knee (24.9%), and thigh (11.0%). Over half (52.9%) recovered within 1 week, while 30.2% lasted beyond 2 weeks. During practices, those injured were approximately 3-fold ( OR 2.83, 95% CI 1.49-5.31) more likely to play on grass than artificial turf and 2.4-fold (95% CI 1.03-5.96) more likely to wear cleats on grass than other shoe and surface combinations. During games injured players were 89% (95% CI 1.03-4.17) more likely to play defender compared to forward. Conclusions Half of the acute lower extremity injuries affected the ankle or knee. Grass surface and wearing cleats on grass increased training injuries. PMID:26327288

Gender differences in game responses during badminton match play.

PubMed

Fernandez-Fernandez, Jaime; de la Aleja Tellez, Jose G; Moya-Ramon, Manuel; Cabello-Manrique, David; Mendez-Villanueva, Alberto

2013-09-01

The aim of this study was to evaluate possible gender differences in match play activity pattern [rally duration, rest time between rallies, effective playing time, and strokes performed during a rally] and exercise intensity (heart rate [HR], blood lactate [La], and subjective ratings of perceived exertion [RPE]) during 9 simulated badminton matches in male (n = 8) and female (n = 8) elite junior (16.0 ± 1.4 years) players. Results showed significant differences (all p < 0.05; effect size (ES) = 0.80-1.56) between male and female players in the activity pattern of match play, with male players engaged in longer rallies (6.8 ± 4.8 vs. 5.7 ± 3.1 seconds), executing more strokes per rally (6.4 ± 4.8 vs. 4.7 ± 2.8) and resting more between rallies (10.5 ± 8.8 vs. 8.8 ± 7.2 seconds) than female players. No clear differences (all p > 0.05; ES = -0.33 to 0.08) were observed between female or male players in average HR (174 ± 7 vs. 170 ± 9 b·min(-1)), %HRmax (89.2 ± 4.0% vs. 85.9 ± 4.3%), La (2.5 ± 1.3 vs. 3.2 ± 1.8 mmol·L(-1)), and RPE values (14.2 ± 1.9 vs. 14.6 ± 1.8) during match play, although male players spent more time (moderate effect sizes) at intensities between 81 and 90% HRmax (35.3 ± 17.9 vs. 25.3 ± 13.6; p < 0.05; ES = 0.64) in the second game. There seemed to be a trend toward an increased playing intensity (i.e., higher HR, La, and RPE) from the first to the second game, highlighting the higher exercise intensity experienced during the last part of the match. The clear between-gender differences in activity patterns induced only slightly different physiological responses.

Complex network study of Brazilian soccer players

NASA Astrophysics Data System (ADS)

Onody, Roberto N.; de Castro, Paulo A.

2004-09-01

Although being a very popular sport in many countries, soccer has not received much attention from the scientific community. In this paper, we study soccer from a complex network point of view. First, we consider a bipartite network with two kinds of vertices or nodes: the soccer players and the clubs. Real data were gathered from the 32 editions of the Brazilian soccer championship, in a total of 13411 soccer players and 127 clubs. We find a lot of interesting and perhaps unsuspected results. The probability that a Brazilian soccer player has worked at N clubs or played M games shows an exponential decay while the probability that he has scored G goals is power law. Now, if two soccer players who have worked at the same club at the same time are connected by an edge, then a new type of network arises (composed exclusively by soccer player nodes). Our analysis shows that for this network the degree distribution decays exponentially. We determine the exact values of the clustering coefficient, the assortativity coefficient and the average shortest path length and compare them with those of the Erdös-Rényi and configuration model. The time evolution of these quantities are calculated and the corresponding results discussed.

Physical fitness, injuries, and team performance in soccer.

PubMed

Arnason, Arni; Sigurdsson, Stefan B; Gudmundsson, Arni; Holme, Ingar; Engebretsen, Lars; Bahr, Roald

2004-02-01

To investigate the relationship between physical fitness and team success in soccer, and to test for differences in physical fitness between different player positions. Participants were 306 male soccer players from 17 teams in the two highest divisions in Iceland. Just before the start of the 1999 soccer season, the following variables were tested: height and weight, body composition, flexibility, leg extension power, jump height, and peak O2 uptake. Injuries and player participation in matches and training were recorded through the 4-month competitive season. Team average physical fitness was compared with team success (final league standing) using a linear regression model. Physical fitness was also compared between players in different playing positions. A significant relationship was found between team average jump height (countermovement jump and standing jump) and team success (P = 0.009 and P = 0.012, respectively). The same trend was also found for leg extension power (P = 0.097), body composition (% body fat, P = 0.07), and the total number of injury days per team (P = 0.09). Goalkeepers demonstrated different fitness characteristics from outfield players. They were taller and heavier, more flexible in hip extension and knee flexion, and had higher leg extension power and a lower peak O2 uptake. However, only minor differences were observed between defenders, midfield players, and attackers. Coaches and medical support teams should pay more attention to jump and power training, as well as preventive measures and adequate rehabilitation of previous injuries to increase team success.

A retrospective study on anthropometrical, physical fitness, and motor coordination characteristics that influence dropout, contract status, and first-team playing time in high-level soccer players aged eight to eighteen years.

PubMed

Deprez, Dieter N; Fransen, Job; Lenoir, Matthieu; Philippaerts, Renaat M; Vaeyens, Roel

2015-06-01

The goal of this article was twofold, and a 2-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance, and motor coordination characteristics that influence dropout from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a "club group" or a "dropout group." In the second study, cross-sectional data of anthropometry, physical performance, and motor coordination were retrospectively explored to investigate which characteristics influence future contract status (contract vs. no contract group) and first-team playing time for 72 high-level youth soccer players (mean age = 16.2 years). Generally, club players outperformed their dropout peers for motor coordination, soccer-specific aerobic endurance, and speed. Anthropometry and estimated maturity status did not discriminate between club and dropout players. Contract players jumped further (p = 0.011) and had faster times for a 5-m sprint (p = 0.041) than no contract players. The following prediction equation explains 16.7% of the variance in future playing minutes in adolescent youth male soccer players: -2,869.3 + 14.6 × standing broad jump. Practitioners should include the evaluation of motor coordination, aerobic endurance, and speed performances to distinguish high-level soccer players further succeeding a talent development program and future dropout players, between 8 and 16 years. From the age of 16 years, measures of explosivity are supportive when selecting players into a future professional soccer career.

Characterization of static balance abilities in elite soccer players by playing position and age.

PubMed

Pau, Massimiliano; Ibba, Gianfranco; Leban, Bruno; Scorcu, Marco

2014-01-01

In this study, we investigated the static balance of adult and adolescent elite soccer players to understand how expertise and playing position influence postural control. Seventy-one national level players were tested using a force platform to acquire Center-of-Pressure (COP) data in uni- and bipedal stance and calculate sway area (SA), COP path length, velocity and displacements. The results show significant differences in postural sway related to age and playing position only for single-limb stance. In particular, midfielders exhibited significantly lower values of SA with respect to defenders (-48%, p = 0.001) and the under-15 players exhibited SA 42-64% higher than all the others (p = 0.001). In the light of planning training or rehabilitation programs specific for each player's role and age, sway measurements may supply useful, objective and reliable information only for the unipedal test as the bipedal standing appears not challenging enough to let differences in balance abilities emerge.

Effect of Soccer Foot Pressure on Pressure Distributions

ERIC Educational Resources Information Center

Uzun, Ahmet; Aydos, Latif; Kaya, Metin; Pekel, H. Ahmet; Kanatli, Ulunay

2018-01-01

The aim of this research is to investigate the effect of playing soccer for a long time in for professional soccer players regarding sole pressure. Despite the increasing prevalence of new methods developed in the footpad pressure measurement in recent years, our knowledge about pressure distribution of the footplate is still insufficient,…

Association of Soccer and Genu Varum in Adolescents

PubMed Central

Asadi, Kamran; Mirbolook, Ahmadreza; Heidarzadeh, Abtin; Mardani Kivi, Mohsen; Emami Meybodi, Mohammad Kazem; Rouhi Rad, Melina

2015-01-01

Background: Genu varum is a physical deformity marked by bowing of the leg. One of the risk factors of this musculoskeletal alignment is stress on the knee joint such as with exercise. Objectives: Since the evaluation of genu varum has not been widely studies, this study was conducted to examine the association between genu varum and playing soccer. Materials and Methods: Between Septembers 2010-2012, 750 soccer players and 750 non-soccer players 10-18 years of age were included in the study. A questionnaire of data including age, height, weight, body mass index (BMI), years of soccer participation, the average time of playing soccer per week, previous trauma to the lower limbs, history of any fractures of the knee, previous hospitalizations, and the distance of joint lines between the knees was assessed for all subjects. Chi-square, student t-test, and one-way ANOVA were used for statistical analysis by SPSS v.19.0 software. In all tests, a P value of less than 0.05 was construed as statistically significant. Results: Both soccer players and controls had genu varum. However, the incidence of genu varum was higher in the soccer players (P = 0.0001) and it was more prevalent in the 16-18 year age group (P = 0.0001). The results revealed a statistically significant association between the degree of practices and the prevalence of genu varum (P = 0.0001). Moreover, previous trauma to the knees and practicing in load-bearing sports led to an increase in the degree of genu varum (P = 0.0001). Conclusions: There was a higher incidence of genu varum in soccer players than in control adolescents; the stress and load imposed on the knee joint led to more severe genu varum. PMID:26290852

Relative risk for concussions in young female soccer players.

PubMed

Strand, Sarah; Lechuga, David; Zachariah, Thomas; Beaulieu, Kathryn

2015-01-01

The objective of this study was to determine the relative risk and reported symptoms of concussions in 11- to 13-year-old, female soccer players. For this, a survey to compare the reported incidence of concussion in age-matched female soccer players to nonsoccer players was performed. The survey included 342 girls between the ages of 11 and 13: 195 were involved in an organized soccer team and 147 were not involved in organized soccer but were allowed to participate in any other sport or activity. A total of 94 of the 195 soccer players, or 48%, reported at least one symptom consistent with a concussion. The most prevalent symptom for these girls was headache (84%). A total of 34 of the 147 nonsoccer players, or 23%, reported at least one symptom consistent with a concussion in the previous six months. These results determined that the relative risk of probable concussions among 11- to 13-year-old, female soccer players is 2.09 (p < .001, α = .05, CI = 95%). This demonstrates that the relative risk of probable concussions in young female soccer players is significantly higher than in a control group of nonsoccer players of the same sex and age.

Can triggers be cumulative in inducing heart attack in soccer game spectators?

PubMed

Tasch, Christoph; Larcher, Lorenz

2012-08-01

Emotional stress and excitement associated with watching soccer matches has been suggested to act as an external trigger for the onset of acute coronary syndromes. We report about a patient of Italian nationality who developed acute coronary syndrome while watching the European football championship match Switzerland vs. Turkey in 2008. Although greater emotional intensity was possibly involved while watching his country play two days earlier (Italy vs Netherlands), he developed no symptoms. Hence, this case throws some interesting light on what can be considered as an acute trigger by discussing the assumption of a cumulative effect regarding to the potential trigger two days before and in which way psychological stress may have influence on the onset of acute coronary syndromes.

Physical and metabolic demands of training and match-play in the elite football player.

PubMed

Bangsbo, Jens; Mohr, Magni; Krustrup, Peter

2006-07-01

In soccer, the players perform intermittent work. Despite the players performing low-intensity activities for more than 70% of the game, heart rate and body temperature measurements suggest that the average oxygen uptake for elite soccer players is around 70% of maximum (VO(2max). This may be partly explained by the 150 - 250 brief intense actions a top-class player performs during a game, which also indicates that the rates of creatine phosphate (CP) utilization and glycolysis are frequently high during a game. Muscle glycogen is probably the most important substrate for energy production, and fatigue towards the end of a game may be related to depletion of glycogen in some muscle fibres. Blood free-fatty acids (FFAs) increase progressively during a game, partly compensating for the progressive lowering of muscle glycogen. Fatigue also occurs temporarily during matches, but it is still unclear what causes the reduced ability to perform maximally. There are major individual differences in the physical demands of players during a game related to physical capacity and tactical role in the team. These differences should be taken into account when planning the training and nutritional strategies of top-class players, who require a significant energy intake during a week.

On the mathematical modeling of soccer dynamics

NASA Astrophysics Data System (ADS)

Machado, J. A. Tenreiro; Lopes, António M.

2017-12-01

This paper addresses the modeling and dynamical analysis of soccer teams. Two modeling perspectives based on the concepts of fractional calculus are adopted. In the first, the power law behavior and fractional-order integration are explored. In the second, a league season is interpreted in the light of a system where the teams are represented by objects (particles) that evolve in time and interact (collide) at successive rounds with dynamics driven by the outcomes of the matches. The two proposed models embed implicitly details of players and coaches, or strategical and tactical maneuvers during the matches. Therefore, the scale of observation focuses on the teams behavior in the scope of the observed variables. Data characterizing two European soccer leagues in the season 2015-2016 are adopted and processed. The model leads to the emergence of patterns that are analyzed and interpreted.

Talent identification and development in soccer.

PubMed

Williams, A M; Reilly, T

2000-09-01

In this review, we attempt to integrate the main research findings concerned with talent identification and development in soccer. Research approaches in anthropometry, physiology, psychology and sociology are considered and, where possible, integrated. Although some progress has been made in identifying correlates of playing success, it appears that no unique characteristics can be isolated with confidence. Both biological and behavioural scientists have indicated a strong genetic component in performance of sports such as soccer; nevertheless, the influence of systematic training and development programmes should not be underestimated. We conclude that the sport and exercise sciences have an important support role in the processes of identifying, monitoring and nurturing talented soccer players towards realizing their potential.

Analysis of Physical Collisions in Elite National Rugby League Match Play.

PubMed

Cummins, Cloe; Orr, Rhonda

2015-09-01

To investigate the impact forces of collision events during both attack and defense in elite rugby league match play and to compare the collision profiles between playing positions. 26 elite rugby league players. Player collisions were recorded using an integrated accelerometer in global positioning system units (SPI-Pro X, GPSports). Impact forces of collisions in attack (hit-ups) and defense (tackles) were analyzed from 359 files from outside backs (n = 78), adjustables (n = 97), wide-running forwards (n = 136), and hit-up forwards (n = 48) over 1 National Rugby League season. Hit-up forwards were involved in 0.8 collisions/min, significantly more than all other positional groups (wide-running forwards P = .050, adjustables P = .042, and outside backs P = .000). Outside backs experienced 25% fewer collisions per minute than hit-up forwards. Hit-up forwards experienced a collision within the 2 highest classifications of force (≥ 10 g) every 2.5 min of match play compared with 1 every 5 and 9 min for adjustables and outside backs, respectively. Hit-up forwards performed 0.5 tackles per minute of match play, 5 times that of outside backs (ES = 1.90; 95% CI [0.26,3.16]), and 0.2 hit-ups per minute of match play, twice as many as adjustables. During a rugby league match, players are exposed to a significant number of collision events. Positional differences exist, with hit-up and wide-running forwards experiencing greater collision events than adjustables and outside backs. Although these results may be unique to the individual team's defensive- and attacking-play strategies, they are indicative of the significant collision profiles in professional rugby league.

Serious shoulder injuries in professional soccer: return to participation after surgery.

PubMed

Hart, David; Funk, Lennard

2015-07-01

An evidence base for the management and prevention of shoulder injuries in soccer is lacking. The aim of this study was to demonstrate the type, mechanism and recovery time after surgery associated with serious shoulder injuries sustained in professional soccer to build an evidence base foundation. Fifty-two professional soccer players underwent shoulder surgery for injuries sustained during match play. Of these, 25 fulfilled the inclusion criteria. Data were collected for injury mechanism and type; clinical, radiological and surgical findings and procedures; and return to full participation. Subjects were all managed by the same surgeon. Labral injuries represented the most common injury type affecting 21 (84 %) subjects; two rotator cuff (8 %) and two combined labral/rotator cuff (8 %) injuries were less common. Fourteen (56 %) subjects sustained a high-energy trauma injury in a combined abduction and external rotation position. Six (24 %) subjects sustained a low-energy trauma mechanism in variable positions, while five (20 %) had a gradual onset of symptoms. Twenty-two (88 %) subjects reported a dislocation as a feature of their presentation. All of the subjects with high- and low-energy trauma mechanisms reported a dislocation occurring at the time of injury. Eight (32 %) subjects had sustained a previous significant shoulder injury to the ipsilateral side. Goalkeepers did not sustain low-energy trauma injuries. Outfield players returned to full participation in a mean time of 11.6 weeks, while goalkeepers did so in 11.1 weeks post-surgery. Return to participation time ranged from 7 to 24 weeks with a median of 11 weeks. Professional soccer players can expect a return to participation within 12 weeks post-surgery. The majority of serious shoulder injuries in soccer occur at a positional extreme of external rotation and abduction in high-energy situations, while a significant number occur in low-energy situations away from this position. Most serious shoulder

The evaluation of small-sided games as a talent identification tool in highly trained prepubertal soccer players.

PubMed

Fenner, Jonathan S J; Iga, John; Unnithan, Viswanath

2016-10-01

The aim of this study was to evaluate physiological and technical attributes of prepubertal soccer players during multiple small-sided games (SSGs), and determine if SSGs can act as a talent identification tool. Sixteen highly trained U10 soccer players participated and separated into two groups of eight. Each group played six small-sided (4 vs. 4) matches of 5-min duration. Each player was awarded total points for the match result and goals scored. A game technical scoring chart was used to rate each player's performance during each game. Time-motion characteristics were measured using micromechanical devices. Total points had a very large significant relationship with game technical scoring chart (r = 0.758, P < 0.001). High-speed running distance had a significantly large correlation with game technical scoring chart (r = 0.547, P < 0.05). Total distance covered had a significant and moderate correlation with game technical scoring chart (r = 0.545, P < 0.05) and total points (r = 0.438, P < 0.05). The results demonstrated a large agreement between the highest-rated players and success in multiple SSGs, possibly due to higher-rated players covering larger distances in total and at high speed. Consequently, multiple SSG could be used to identify the more talented prepubertal soccer players.

Thermal, physiological and perceptual strain mediate alterations in match-play tennis under heat stress.

PubMed

Périard, Julien D; Racinais, Sébastien; Knez, Wade L; Herrera, Christopher P; Christian, Ryan J; Girard, Olivier

2014-04-01

This study compared the thermal, physiological and perceptual responses associated with match-play tennis in HOT (∼34°C wet-bulb-globe temperature (WBGT)) and COOL (∼19°C WBGT) conditions, along with the accompanying alterations in match characteristics. 12 male tennis players undertook two matches for an effective playing time (ie, ball in play) of 20 min, corresponding to ∼119 and ∼102 min of play in HOT and COOL conditions, respectively. Rectal and skin temperatures, heart rate, subjective ratings of thermal comfort, thermal sensation and perceived exertion were recorded, along with match characteristics. End-match rectal temperature increased to a greater extent in the HOT (∼39.4°C) compared with the COOL (∼38.7°C) condition (p<0.05). Thigh skin temperature was higher throughout the HOT match (p<0.001). Heart rate, thermal comfort, thermal sensation and perceived exertion were also higher during the HOT match (p<0.001). Total playing time was longer in the HOT compared with the COOL match (p<0.05). Point duration (∼7.1 s) was similar between conditions, while the time between points was ∼10 s longer in the HOT relative to the COOL match (p<0.05). This led to a ∼3.4% lower effective playing percentage in the heat (p<0.05). Although several thermal, physiological and perceptual variables were individually correlated to the adjustments in time between points and effective playing percentage, thermal sensation was the only predictor variable associated with both adjustments (p<0.005). These adjustments in match-play tennis characteristics under severe heat stress appear to represent a behavioural strategy adopted to minimise or offset the sensation of environmental conditions being rated as difficult.

Thermal, physiological and perceptual strain mediate alterations in match-play tennis under heat stress

PubMed Central

Périard, Julien D; Racinais, Sébastien; Knez, Wade L; Herrera, Christopher P; Christian, Ryan J; Girard, Olivier

2014-01-01

Objectives This study compared the thermal, physiological and perceptual responses associated with match-play tennis in HOT (∼34°C wet-bulb-globe temperature (WBGT)) and COOL (∼19°C WBGT) conditions, along with the accompanying alterations in match characteristics. Methods 12 male tennis players undertook two matches for an effective playing time (ie, ball in play) of 20 min, corresponding to ∼119 and ∼102 min of play in HOT and COOL conditions, respectively. Rectal and skin temperatures, heart rate, subjective ratings of thermal comfort, thermal sensation and perceived exertion were recorded, along with match characteristics. Results End-match rectal temperature increased to a greater extent in the HOT (∼39.4°C) compared with the COOL (∼38.7°C) condition (p<0.05). Thigh skin temperature was higher throughout the HOT match (p<0.001). Heart rate, thermal comfort, thermal sensation and perceived exertion were also higher during the HOT match (p<0.001). Total playing time was longer in the HOT compared with the COOL match (p<0.05). Point duration (∼7.1 s) was similar between conditions, while the time between points was ∼10 s longer in the HOT relative to the COOL match (p<0.05). This led to a ∼3.4% lower effective playing percentage in the heat (p<0.05). Although several thermal, physiological and perceptual variables were individually correlated to the adjustments in time between points and effective playing percentage, thermal sensation was the only predictor variable associated with both adjustments (p<0.005). Conclusions These adjustments in match-play tennis characteristics under severe heat stress appear to represent a behavioural strategy adopted to minimise or offset the sensation of environmental conditions being rated as difficult. PMID:24668377

Evidence of Cognitive Dysfunction after Soccer Playing with Ball Heading Using a Novel Tablet-Based Approach

PubMed Central

Lin, Angela H.; Patel, Saumil S.; Sereno, Anne B.

2013-01-01

Does frequent head-to-ball contact cause cognitive dysfunctions and brain injury to soccer players? An iPad-based experiment was designed to examine the impact of ball-heading among high school female soccer players. We examined both direct, stimulus-driven, or reflexive point responses (Pro-Point) as well as indirect, goal-driven, or voluntary point responses (Anti-Point), thought to require cognitive functions in the frontal lobe. The results show that soccer players were significantly slower than controls in the Anti-Point task but displayed no difference in Pro-Point latencies, indicating a disruption specific to voluntary responses. These findings suggest that even subconcussive blows in soccer can result in cognitive function changes that are consistent with mild traumatic brain injury of the frontal lobes. There is great clinical and practical potential of a tablet-based application for quick detection and monitoring of cognitive dysfunction. PMID:23460843

Sleep Hygiene and Recovery Strategies in Elite Soccer Players.

PubMed

Nédélec, Mathieu; Halson, Shona; Delecroix, Barthélémy; Abaidia, Abd-Elbasset; Ahmaidi, Said; Dupont, Gregory

2015-11-01

In elite soccer, players are frequently exposed to various situations and conditions that can interfere with sleep (e.g., playing night matches interspersed with 3 days; performing activities demanding high levels of concentration close to bedtime; use of products containing caffeine or alcohol in the period preceding bedtime; regular daytime napping throughout the week; variable wake-up times or bedtime), potentially leading to sleep deprivation. We outline simple, practical, and pharmaceutical-free sleep strategies that are coordinated to the constraints of elite soccer in order to promote sleep. Sleep deprivation is best alleviated by sleep extension; however, sleep hygiene strategies (i.e., consistent sleep pattern, appropriate napping, and active daytime behaviors) can be utilized to promote restorative sleep. Light has a profound impact on sleep, and sleep hygiene strategies that support the natural environmental light-dark cycle (i.e., red-light treatment prior to sleep, dawn-simulation therapy prior to waking) and prevent cycle disruption (i.e., filtering short wavelengths prior to sleep) may be beneficial to elite soccer players. Under conditions of inordinate stress, techniques such as brainwave entrainment and meditation are promising sleep-promoting strategies, but future studies are required to ascertain the applicability of these techniques to elite soccer players. Consuming high-electrolyte fluids such as milk, high-glycemic index carbohydrates, some forms of protein immediately prior to sleep, as well as tart cherry juice concentrate and tryptophan may promote rehydration, substrate stores replenishment, muscle-damage repair and/or restorative sleep. The influence of cold water immersion performed close to bedtime on subsequent sleep is still debated. Conversely, the potential detrimental effects of sleeping medication must be recognized. Sleep initiation is influenced by numerous factors, reinforcing the need for future research to identify such

Maturity status and injury risk in youth soccer players.

PubMed

Malina, Robert M

2010-03-01

To investigate the association of relative skeletal age and other risk factors with injury in elite schoolboy footballers (soccer players). Prospective cohort study, with players participating for varying numbers of years. Manchester United Football Club Academy, 2001 to 2007. Players were recruited to the club by scouts. At intake, the boys were medically screened to ensure they could be fully involved in the training and games program. Computerized medical records for the boys were maintained for the entire study period. The investigation included boys 9 to 16 years of age. Numbers varied between 98 and 144 per year (mean n/y = 130) over 6 years. Overall, 292 players were represented in the sample. Mean drop out per season was 21%. Each year consenting players had a radiograph of the left wrist and hand for the assessment of skeletal age (SA), using the Fels method. Eighty-five players had at least 1 radiograph and 12 players had 6 radiographs, 1 in each year of the study. Early and late maturers were those with an SA >1 year older or younger, respectively, than their chronologic age (CA). Information on demographics, height and weight, playing and training times, and position played was collected. The main outcome measure was the relation of maturity status to the occurrence of injuries. For the total sample across all the age groups the incidence of injuries was 1.44 per 1000 hours of training (n = 244 injuries), and 10.5 per 1000 match hours (n = 169 injuries). The mean number of injuries per season was 79.3, with a mean loss of 12.5 injury days per player per season. Boys aged <14 years were most vulnerable. Most injuries resulted from overuse rather than from trauma. Most common injury type and location were, respectively, soft tissue and knee joint. Mean SA for the total sample was in advance of mean CA (12.08y vs 11.74y; P < 0.05). Injury incidence did not differ significantly among late, normal, and early maturing players (1.4, 1.5, and 1.8, respectively

Concussion Incidence and Recurrence in Professional Australian Football Match-Play: A 14-Year Analysis

PubMed Central

2017-01-01

Background Concussion incidence rates in professional Australian football may be underreported due to the injury classification definition. A myriad of factors contribute to concussion risk; however, there is limited long-term surveillance in Australian football. This study analysed concussion in one Australian football team over an extended period. Method Match-play concussion injuries in one team (n = 116 participants) were diagnosed and treated by the team physician over 14 years. Analysis of factors related to concussion including matches played, time of day and season, and return to play provided an insight into occurrence and recurrence rates. Results 140 concussions were recorded (17.6 per 1000 player match hours). A strong relationship was evident between matches played and concussion incidence (r = 0.70) and match conditions did not negatively affect the concussion rate. Whether an athlete returned to play in the same match or suffered a loss-of-consciousness concussion (p = 0.84), their ensuing rate of concussion was not affected. Conclusion Concussion in professional Australian football was related to the number of matches played. Further, neither previous incidence nor loss of consciousness affected future concussion risk. This study provides ecologically valid evidence of the concussion incidence rate in professional Australian football and has implications for the management of athletes sustaining concussion injuries. PMID:28804753

The specificity of the Loughborough Intermittent Shuttle Test for recreational soccer players is independent of their intermittent running ability.

PubMed

Coratella, Giuseppe; Beato, Marco; Schena, Federico

2016-01-01

The aim of the present study was to evaluate whether or not recreational soccer players (SP) and non-soccer players (non-SP) with similar intermittent-running ability had similar physiological responses to a soccer match-simulation protocol. Twenty-two recreational SP and 19 fitness-matched non-SP participated. Yo-Yo level 1 assessed intermittent-running ability, while the Loughborough Intermittent Shuttle Test served as soccer match-simulation protocol. Heart rate (HR), blood lactate concentration [La - ] and rating of perceived exertion (RPE) were recorded after each bout (1-5, plus an exhaustive task). SP had lower HR after the third, fourth and fifth bout, compared to non-SP. Similarly, SP had lower [La - ] after the third, fourth and the fifth bout. SP also had lower RPE after the third, fourth and fifth bout. The appropriateness of intermittent-running ability as the main determinant of physical performance in SP was questioned.

Cognitive representations and cognitive processing of team-specific tactics in soccer.

PubMed

Lex, Heiko; Essig, Kai; Knoblauch, Andreas; Schack, Thomas

2015-01-01

Two core elements for the coordination of different actions in sport are tactical information and knowledge about tactical situations. The current study describes two experiments to learn about the memory structure and the cognitive processing of tactical information. Experiment 1 investigated the storage and structuring of team-specific tactics in humans' long-term memory with regard to different expertise levels. Experiment 2 investigated tactical decision-making skills and the corresponding gaze behavior, in presenting participants the identical match situations in a reaction time task. The results showed that more experienced soccer players, in contrast to less experienced soccer players, possess a functionally organized cognitive representation of team-specific tactics in soccer. Moreover, the more experienced soccer players reacted faster in tactical decisions, because they needed less fixations of similar duration as compared to less experienced soccer players. Combined, these experiments offer evidence that a functionally organized memory structure leads to a reaction time and a perceptual advantage in tactical decision-making in soccer. The discussion emphasizes theoretical and applied implications of the current results of the study.

Cognitive Representations and Cognitive Processing of Team-Specific Tactics in Soccer

PubMed Central

Lex, Heiko; Essig, Kai; Knoblauch, Andreas; Schack, Thomas

2015-01-01

Two core elements for the coordination of different actions in sport are tactical information and knowledge about tactical situations. The current study describes two experiments to learn about the memory structure and the cognitive processing of tactical information. Experiment 1 investigated the storage and structuring of team-specific tactics in humans’ long-term memory with regard to different expertise levels. Experiment 2 investigated tactical decision-making skills and the corresponding gaze behavior, in presenting participants the identical match situations in a reaction time task. The results showed that more experienced soccer players, in contrast to less experienced soccer players, possess a functionally organized cognitive representation of team-specific tactics in soccer. Moreover, the more experienced soccer players reacted faster in tactical decisions, because they needed less fixations of similar duration as compared to less experienced soccer players. Combined, these experiments offer evidence that a functionally organized memory structure leads to a reaction time and a perceptual advantage in tactical decision-making in soccer. The discussion emphasizes theoretical and applied implications of the current results of the study. PMID:25714486

The Physiological Profile of Junior Soccer Players at SSBB Surabaya Bhakti

NASA Astrophysics Data System (ADS)

Nashirudin, M.; Kusnanik, N. W.

2018-01-01

Soccer players are required to have good physical fitness in order to achieve optimum accomplishment; physical fitness stands as the foundation of technical and tactical proficiency as well as the mental maturity during the matches. The purpose of this study was to identify the physiological profile of junior soccer players of SSB Surabaya Bhakti age 16-17. The research was conducted at 20 junior soccer players. This research was quantitative with descriptive analysis. Data were collected by testing of physiological (anaerobic power and capacity including explosive leg power, speed, agility; aerobic capacity: cardiovascular endurance). Data was analyzed using percentage. The result showed that the percentage of explosive leg power of junior soccer players were 30% (good category), speed was 85% (average category), right agility was 90% (average category), left agility was 75% (average category). On the other hand, the aerobic power and capacity of the junior soccer players in this study was 50% (average category). The conclusion of this research is that the physiological profile of junior soccer players at SSB Surabaya Bhakti age 16-17 was majority in average category.

Professional soccer is associated with radiographic cam and pincer hip morphology.

PubMed

Falotico, Guilherme Guadagnini; Arliani, Gustavo Gonçalves; Yamada, André Fukunishi; Fernandes, Artur da Rocha Correa; Ejnisman, Benno; Cohen, Moises

2018-06-06

Femoroacetabular impingement (FAI) syndrome is characterized by a triad: symptoms, clinical signs and imaging findings. Some individuals, especially athletes, have only imaging alterations. The objective of this study was to evaluate the prevalence of cam and pincer morphology in professional soccer players compared with a control group of non-athletes and to investigate the association between the age at which players start playing competitive soccer more than three times per week and duration of the soccer career with the prevalence of these radiographic findings. The prevalence of cam and pincer morphology in sixty professional adult male soccer players and thirty-two male controls was determined using pelvic anteroposterior radiography. Data were recorded for all hips and correlated with the age at which the players started competitive soccer practice and with the duration of their soccer career. The prevalence of morphological FAI in the soccer players was 92.5% versus 28.1% in the controls (p < 0.001). The duration of the soccer career was positively correlated with the alpha angle (p = 0.033) and negatively correlated with the retroversion index (p = 0.009). The age at which competitive play began was inversely correlated with the alpha angle (p < 0.001). The study showed a high prevalence of cam and pincer morphology in Brazilian professional soccer players compared with controls. The duration of the soccer career was associated with an increased alpha angle and a decreased retroversion index, and the age at which competitive soccer participation began was negatively associated with alpha angle values. Finally, this manuscript provides data about the association between greater exposure to soccer and cam and pincer morphological changes in the hip; specifically, cam morphology was more common in patients who began participating in sports at earlier ages. This information serves as an alert for coaches of youth teams to manage the training

Biomechanical and functional indicators in male semiprofessional soccer players with increased hip alpha angles vs. amateur soccer players.

PubMed

Lahner, Matthias; von Schulze Pellengahr, Christoph; Walter, Philipp Alexander; Lukas, Carsten; Falarzik, Andreas; Daniilidis, Kiriakos; von Engelhardt, Lars Victor; Abraham, Christoph; Hennig, Ewald M; Hagen, Marco

2014-03-16

Femoroacetabular impingement (FAI) is predominant in young male athletes, but not much is known about gait differences in cases of increased hip alpha angles. In our study, the hip alpha angle of Nötzli of soccer players was quantified on the basis of magnetic resonance imaging (MRI) with axial oblique sequences. The aim of the current study was to compare the rearfoot motion and plantar pressure in male semiprofessional soccer players with increased alpha angles to age-matched amateur soccer players. In a prospective analysis, male semiprofessional and amateur soccer players had an MRI of the right hip to measure the alpha angle of Nötzli. In a biomechanical laboratory setting, 14 of these participants in each group ran in two shoe conditions. Simultaneously in-shoe pressure distribution, tibial acceleration, and rearfoot motion measurements of the right foot were performed. In the semiprofessional soccer group, the mean value of the alpha angle of group was 55.1 ± 6.58° (range 43.2-76.6°) and 51.6 ± 4.43° (range 41.9-58.8°) in the amateur group. In both shoe conditions, we found a significant difference between the two groups concerning the ground reaction forces, tibial acceleration, rearfoot motion and plantar pressure parameters (P < 0.01, P < 0.05, P = 0.04). Maximum rearfoot motion is about 22% lower in the semiprofessional group compared to the amateur group in both shoe conditions. This study confirmed that semiprofessional soccer players with increased alpha angles showed differences in gait kinematics compared to the amateur group. These findings support the need for a screening program for competitive soccer players. In cases of a conspicuous gait analysis and symptomatic hip pain, FAI must be ruled out by further diagnostic tests.

Allometric multilevel modelling of agility and dribbling speed by skeletal age and playing position in youth soccer players.

PubMed

Valente-dos-Santos, J; Coelho-e-Silva, M J; Duarte, J; Pereira, J; Rebelo-Gonçalves, R; Figueiredo, A; Mazzuco, M A; Sherar, L B; Elferink-Gemser, M T; Malina, R M

2014-08-01

This study evaluates the contributions of age, skeletal maturation, body size and composition, training and playing position to the development of agility and dribbling speed in young male soccer players (10-18 years) followed longitudinally. 83 players [defenders (n=35), midfielders (n=27), forwards (n=21)] were followed annually over 5 years (average: 4.4 observations per player). Skeletal age (SA), stature, body mass, triceps and subscapular skinfolds, agility and dribbling speed were measured annually. Body composition was estimated from the 2 skinfolds. Annual training volume was estimated from weekly participation forms completed by coaches. The multiplicative allometric models with the best statistical fit showed that statural growth of 1 cm predicts 1.334 s and 1.927 s of improvement in agility and dribbling speed, respectively. Significant independent effects of fat-free mass and annual volume training were found for agility and dribbling speed, respectively (P<0.05). Predicted agility (from 12 to 18 years of SA) and dribbling speed (from 13 to 18 years of SA) differed significantly among players by playing positions (midfielders>forwards>defenders). The present results provide developmental models for the interpretation of intra- and inter-individual variability in agility and dribbling speed among youth soccer players across adolescence, and may provide a framework for trainers and coaches to develop and evaluate individualized training protocols. © Georg Thieme Verlag KG Stuttgart · New York.

In-season training periodization of professional soccer players

PubMed Central

Mendez-Villanueva, A; Martínez-Santos, R

2017-01-01

The aim of this study was to quantify the seasonal perceived respiratory and muscular training loads (i.e., sRPEres-TL and sRPEmus-TL) completed by elite-oriented young professional soccer players. Twenty-four players (20.3 ± 2.0 years) belonging to the same reserve team of a Spanish La Liga club participated in this study. Only the players that were available to train for a whole week with the team and also to play the weekly game were considered: Starters, players that participated in the match for at least 45 min and Non-Starters, players that did not participate or played less than 45 minutes in the match. The competitive period was analysed after the division into 5x6-8 week blocks and 35x1 week microcycles. Data were also analysed with respect to number of days before the immediate match. Weekly TL variation across the in-season blocks was trivial-small for both groups except between Block 2 and Block 3 (ES= moderate). Substantial TL differences (ES= small–very likely) were found between training days, the TL pattern being a progressive increase up to MD-3 followed by a decrease until MD-1. Except for the match, sRPEres-/sRPEmus-TL was very similar between Starters and Non-Starters. In summary, perceived TL across the season displayed limited variation. Coaches periodized training contents to attain the highest weekly TL 72 hours before the match to progressively unload the players between MD-3 and the match day. The data revealed that the TL arising from the weekly game was solely responsible for the observed higher weekly TL of Starters in comparison with Non-Starters. PMID:28566808

Soccer activity profile of altitude versus sea-level natives during acclimatisation to 3600 m (ISA3600).

PubMed

Aughey, Robert J; Hammond, Kristal; Varley, Matthew C; Schmidt, Walter F; Bourdon, Pitre C; Buchheit, Martin; Simpson, Ben; Garvican-Lewis, Laura A; Kley, Marlen; Soria, Rudy; Sargent, Charli; Roach, Gregory D; Claros, Jesus C Jimenez; Wachsmuth, Nadine; Gore, Christopher J

2013-12-01

We investigated the effect of high altitude on the match activity profile of elite youth high altitude and sea level residents. Twenty Sea Level (Australian) and 19 Altitude-resident (Bolivian) soccer players played five games, two near sea level (430 m) and three in La Paz (3600 m). Match activity profile was quantified via global positioning system with the peak 5 min period for distance ((D₅(peak)) and high velocity running (>4.17 m/s, HIVR₅(peak)); as well as the 5 min period immediately subsequent to the peak for both distance (D₅(sub)) and high-velocity running (HIVR₅(sub)) identified using a rolling 5 min epoch. The games at 3600 m were compared with the average of the two near sea-level games. The total distance per minute was reduced by a small magnitude in the first match at altitude in both teams, without any change in low-velocity running. There were variable changes in HiVR, D₅(peak) and HiVR₅(peak) from match to match for each team. There were within-team reductions in D₅(peak) in each game at altitude compared with those at near sea level, and this reduction was greater by a small magnitude in Australians than Bolivians in game 4. The effect of altitude on HiVR₅(peak) was moderately lower in Australians compared with Bolivians in game 3. There was no clear difference in the effect of altitude on maximal accelerations between teams. High altitude reduces the distance covered by elite youth soccer players during matches. Neither 13 days of acclimatisation nor lifelong residence at high altitude protects against detrimental effects of altitude on match activity profile.

Effectiveness and cost-effectiveness of an injury prevention programme for adult male amateur soccer players: design of a cluster-randomised controlled trial

PubMed Central

Krist, Mark R; Schmikli, Sandor L; Stubbe, Janine H; de Wit, G Ardine; Inklaar, Han; van de Port, Ingrid G L; Backx, Frank J G

2010-01-01

Background and aims Approximately 16% of all sports injuries in the Netherlands are caused by outdoor soccer. A cluster-randomised controlled trial has been designed to investigate the effectiveness and cost-effectiveness of an injury prevention programme (‘The11’) for male amateur soccer players. The injury prevention programme The11, developed with the support of the World Football Association FIFA, aims to reduce the impact of intrinsic injury risk factors in soccer. Methods Teams playing at first-class amateur level in two districts in the Netherlands are participating in the study. Teams in the intervention group were instructed to apply The11 during each practice session throughout the 2009–10 season. All participants of the control group continued their practice sessions as usual. All soccer-related injuries and related costs for each team were systematically reported online by a member of the medical staff. Player exposure to practice sessions and matches was reported weekly by the coaches. Also the use of The11 during the season after the intervention season will be monitored. Discussion Our hypothesis is that integrating the The11 exercises in the warm-up for each practice session is effective in terms of injury incidence, injury severity, healthcare use, and its associated costs and/or absenteeism. Prevention of soccer injuries is expected to be beneficial to adult soccer players, soccer clubs, the Royal Dutch Football Association (KNVB), health insurance companies and society. PMID:21177664

Match analysis of U9 and U10 english premier league academy soccer players using a global positioning system: relevance for talent identification and development.

PubMed

Goto, Heita; Morris, John G; Nevill, Mary E

2015-04-01

The purpose of this study was to examine the match activity profile of U9 and U10 elite soccer players and to establish if there were any differences between players who were subsequently retained or released by their clubs. Such information should prove valuable in the design of training programs for these very young players and in the talent identification and development process. A Global Positioning System was used to analyze 2-4 interacademy 6-a-side matches of English Premier League Academy players (U9: N = 22 and U10: N = 12) who trained 3 times a week (4.5 hours). Speed zones were created based on 5 and 10-m sprint times, and an independent sample t-test was employed for a statistical analysis. Both squads covered ∼4,000 m in total or ∼4,700 m·h during a match (p = NS between squads), with the U10 squad tending to cover a greater distance at moderate (p = 0.10) and high speeds (p = 0.08) than the U9 squad. Retained group covered a greater distance than released group (retained vs. released: 4,478 ± 513 m vs. 4,091 ± 462 m, p < 0.05) during a match and covered a greater distance during low-speed running in absolute (1,226 ± 259 m vs. 1,005 ± 221 m, p < 0.05) and relative (1,325 ± 235 m·h vs. 1,132 ± 210 m·h, p < 0.05) terms. Thus, U9 and U10 players cover over 4000 m in match play, and those players who are retained by academies cover a greater distance in total and at low speeds (2.1-3.1 m·s). This information may support the preparation of squad training programs and the talent identification and development process.

Testosterone and cortisol release among Spanish soccer fans watching the 2010 World Cup final.

PubMed

van der Meij, Leander; Almela, Mercedes; Hidalgo, Vanesa; Villada, Carolina; Ijzerman, Hans; van Lange, Paul A M; Salvador, Alicia

2012-01-01

This field study investigated the release of testosterone and cortisol of a vicarious winning experience in Spanish fans watching the finals between Spain and the Netherlands in the 2010 FIFA World Cup Soccer. Spanish fans (n = 50) watched the match with friends or family in a public place or at home and also participated in a control condition. Consistent with hypotheses, results revealed that testosterone and cortisol levels were higher when watching the match than on a control day. However, neither testosterone nor cortisol levels increased after the victory of the Spanish team. Moreover, the increase in testosterone secretion was not related to participants' sex, age or soccer fandom, but the increase in total cortisol secretion during the match was higher among men than among women and among fans that were younger. Also, increases in cortisol secretion were greater to the degree that people were a stronger fan of soccer. Level of fandom further appeared to account for the sex effect, but not for the age effect. Generally, the testosterone data from this study are in line with the challenge hypothesis, as testosterone levels of watchers increased to prepare their organism to defend or enhance their social status. The cortisol data from this study are in line with social self-preservation theory, as higher cortisol secretion among young and greater soccer fans suggests that especially they perceived that a negative outcome of the match would threaten their own social esteem.

Testosterone and Cortisol Release among Spanish Soccer Fans Watching the 2010 World Cup Final

PubMed Central

van der Meij, Leander; Almela, Mercedes; Hidalgo, Vanesa; Villada, Carolina; IJzerman, Hans; van Lange, Paul A. M.; Salvador, Alicia

2012-01-01

This field study investigated the release of testosterone and cortisol of a vicarious winning experience in Spanish fans watching the finals between Spain and the Netherlands in the 2010 FIFA World Cup Soccer. Spanish fans (n = 50) watched the match with friends or family in a public place or at home and also participated in a control condition. Consistent with hypotheses, results revealed that testosterone and cortisol levels were higher when watching the match than on a control day. However, neither testosterone nor cortisol levels increased after the victory of the Spanish team. Moreover, the increase in testosterone secretion was not related to participants' sex, age or soccer fandom, but the increase in total cortisol secretion during the match was higher among men than among women and among fans that were younger. Also, increases in cortisol secretion were greater to the degree that people were a stronger fan of soccer. Level of fandom further appeared to account for the sex effect, but not for the age effect. Generally, the testosterone data from this study are in line with the challenge hypothesis, as testosterone levels of watchers increased to prepare their organism to defend or enhance their social status. The cortisol data from this study are in line with social self-preservation theory, as higher cortisol secretion among young and greater soccer fans suggests that especially they perceived that a negative outcome of the match would threaten their own social esteem. PMID:22529940

Body composition and nutritional assessments in soccer.

PubMed

Rico-Sanz, J

1998-06-01

This review summarizes results from studies investigating the physical characteristics, daily energy expenditures, diets, and effects of nutritional supplements to the habitual diets of soccer players. The results show that players fall within a wide range of stature and body weight, and they are classified as mesomorphs. The body fat of male players is about 10% of body weight, whereas the average for females is about 21%. Energy expenditure for males is about 4,000 kcal on training days and 3,800 kcal on match day, while energy intake reported in other studies is on the order of 3,700 kcal. Carbohydrate (CHO), fat, and protein intakes are about 53, 30, and 14% of energy intake, respectively, the remaining being from alcohol intake. There are indications that CHO supplements might be beneficial during soccer performance. However, more research is needed to clarify the importance of branched-chain amino acid and creatine supplementation in soccer.

Prematch salivary secretory immunoglobulin a in soccer players from the 2014 World Cup qualifying campaign.

PubMed

Morgans, Ryland; Owen, Adam; Doran, Dominic; Drust, Barry; Morton, James P

2015-04-01

To monitor resting salivary secretory immunoglobulin A (SIgA) levels in international soccer players during the short-term training period that precedes international match play. In a repeated-measure design, saliva samples were obtained from 13 outfield soccer players who participated in the training camps preceding 7 games (5 home and 2 away) of the 2014 FIFA World Cup qualifying campaign. Samples were obtained daily for 4 d preceding each game (and analyzed for SIgA using the IPRO oral-fluid-collection system) at match day minus 1 (MD-1), minus 2 (MD-2), minus 3 (MD-3), and minus 4 (MD-4). SIgA displayed a progressive decline (P = .01) during the 4-d training period (MD-4, 365 ± 127 μg/mL; MD-3, 348 ± 154 μg/mL; MD-2, 290 ± 138 μg/mL; MD-1, 256 ± 90 μg/mL) such that MD-1 values were significantly lower (P = .01) than both MD-4 and MD-3. The 95% confidence intervals for the differences between MD-1 and MD-4 were -191 to -26 and between MD-1 and MD-3 were -155 to -28. Data demonstrate that a short-term soccer-training camp in preparation for international competition induces detectable perturbations to mucosal immunity. Future studies should monitor SIgA (as a practical and noninvasive measure of immunity) alongside internal and external measures of training load in an attempt to strategically individualize training and nutritional strategies that may support optimal preparation for high-level competition.

The Generalized Matching Law in Elite Sport Competition: Football Play Calling as Operant Choice

PubMed Central

Reed, Derek D; Critchfield, Thomas S; Martens, Brian K

2006-01-01

A mathematical model of operant choice, the generalized matching law was used to analyze play-calling data from the 2004 National Football League season. In all analyses, the relative ratio of passing to rushing plays was examined as a function of the relative ratio of reinforcement, defined as yards gained, from passing versus rushing. Different analyses focused on season-aggregate data for the league as a whole, game-by-game data for the league as a whole, and game-by-game data for individual teams. In all analyses except those for a few individual teams, the generalized matching law accounted for a majority of variance in play calling. The typical play-calling pattern reflected undermatching (suggesting imperfect sensitivity of play calling to yardage-gained reinforcers) and a bias for calling rushing plays. Bias was found to be a function of both the relative risk of turnovers and the relative variability in yards gained associated with passing versus rushing plays. The external validity of the matching analyses was supported by significant correlations between parameters of the generalized matching law and team success on offense and season winning percentage. These results illustrate the broad applicability of the generalized matching law to problems outside of the laboratory. PMID:17020210

Energetics of high-intensity exercise (soccer) with particular reference to fatigue.

PubMed

Reilly, T

1997-06-01

Soccer entails intermittent exercise with bouts of short, intense activity punctuating longer periods of low-level, moderate-intensity exercise. High levels of blood lactate may sometimes be observed during a match but the active recovery periods at submaximal exercise levels allow for its removal on a continual basis. While anaerobic efforts are evident in activity with the ball and shadowing fast-moving opponents, the largest strain is placed on aerobic metabolism. On average, competitive soccer corresponds to an energy expenditure of about 75% maximal aerobic power. The energy expenditure varies with playing position, being highest among midfield players. Muscle glycogen levels can be reduced towards the end of a game, the level of reduction being reflected in a decrease in work rate. Blood glucose levels are generally well-maintained, although body temperature may rise by 2 degrees C even in temperate conditions. The distance covered by players tends to under-reflect the energy expended. Unorthodox modes of motion-running backwards and sideways, accelerating, decelerating and changing direction-accentuate the metabolic loading. These are compounded by the extra requirements for energy associated with dribbling the ball and contesting possession. The overall energy expended is extreme when players are required to play extra-time in tournaments. Training, nutritional and tactical strategies may be used to reduce the effects of fatigue that may occur late in the game.

SoccerStories: a kick-off for visual soccer analysis.

PubMed

Perin, Charles; Vuillemot, Romain; Fekete, Jean-Daniel

2013-12-01

This article presents SoccerStories, a visualization interface to support analysts in exploring soccer data and communicating interesting insights. Currently, most analyses on such data relate to statistics on individual players or teams. However, soccer analysts we collaborated with consider that quantitative analysis alone does not convey the right picture of the game, as context, player positions and phases of player actions are the most relevant aspects. We designed SoccerStories to support the current practice of soccer analysts and to enrich it, both in the analysis and communication stages. Our system provides an overview+detail interface of game phases, and their aggregation into a series of connected visualizations, each visualization being tailored for actions such as a series of passes or a goal attempt. To evaluate our tool, we ran two qualitative user studies on recent games using SoccerStories with data from one of the world's leading live sports data providers. The first study resulted in a series of four articles on soccer tactics, by a tactics analyst, who said he would not have been able to write these otherwise. The second study consisted in an exploratory follow-up to investigate design alternatives for embedding soccer phases into word-sized graphics. For both experiments, we received a very enthusiastic feedback and participants consider further use of SoccerStories to enhance their current workflow.

A low-cost method for estimating energy expenditure during soccer refereeing.

PubMed

Ardigò, Luca Paolo; Padulo, Johnny; Zuliani, Andrea; Capelli, Carlo

2015-01-01

This study aimed to apply a validated bioenergetics model of sprint running to recordings obtained from commercial basic high-sensitivity global positioning system receivers to estimate energy expenditure and physical activity variables during soccer refereeing. We studied five Italian fifth division referees during 20 official matches while carrying the receivers. By applying the model to the recorded speed and acceleration data, we calculated energy consumption during activity, mass-normalised total energy consumption, total distance, metabolically equivalent distance and their ratio over the entire match and the two halves. Main results were as follows: (match) energy consumption = 4729 ± 608 kJ, mass normalised total energy consumption = 74 ± 8 kJ · kg(-1), total distance = 13,112 ± 1225 m, metabolically equivalent distance = 13,788 ± 1151 m and metabolically equivalent/total distance = 1.05 ± 0.05. By using a very low-cost device, it is possible to estimate the energy expenditure of soccer refereeing. The provided predicting mass-normalised total energy consumption versus total distance equation can supply information about soccer refereeing energy demand.

Quantification and Analysis of Offensive Situations in Different Formats of Sided Games In Soccer

PubMed Central

Garcia, Jorge Diaz-Cidoncha; Román, Ignacio Refoyo; Calleja-González, Julio; Dellal, Alexandre

2014-01-01

There has been a lot of research that enabled soccer to improve: its technique, tactics and strategy through analysis and training. Nevertheless, players’ need to interact with each other turns any defending or attacking situation into complex solutions with a wide range of variables to be considered, in which the player is never isolated and must make the move that has the most positive impact on play. Fifty-four sided games played in three different formats (5v5, 7v7 and 9v9) and with two age groups (U9 and U14) were filmed at three soccer clubs in Spain in order to identify the most relevant attacking moves, from a technical and tactical perspective. This study used the observational method; it is descriptive and is applied through well-prepared systematic quantitative observation in a natural environment. A key part of the method involved viewing the match recordings and logging moves that had been categorised beforehand. Cohen’s Kappa analysis showed that the results for the most representative variables presented a substantial degree of concordance (0.61–0.80). The results show that there were significant variations depending on the game format, and the following study will present a description and analysis of the aspects that had considerable influence on attacking moves in different formats of sided games (5v5, 7v7 and 9v9). The study also presents various practical applications for the area of training and analysing both youth and professional soccer. PMID:25713680

Concussions and Head Injuries in English Community Rugby Union Match Play.

PubMed

Roberts, Simon P; Trewartha, Grant; England, Michael; Goodison, William; Stokes, Keith A

2017-02-01

Previous research has described general injury patterns in community-level rugby union, but specific information on time-loss head injuries has not been reported. To establish the incidence and nature of significant time-loss head injuries in English community rugby match play, and to identify the injury risk for specific contact events. Descriptive epidemiology study. Over 6 seasons, injury information was collected from 46 (2009-2010), 67 (2010-2011), 76 (2011-2012), 50 (2012-2013), 67 (2013-2014), and 58 (2014-2015) English community rugby clubs (Rugby Football Union levels 3-9) over a total of 175,940 hours of player match exposure. Club injury management staff reported information for all head injuries sustained during match play whereby the player was absent for 8 days or greater. Clubs were subdivided into semiprofessional (mean player age, 24.6 ± 4.7 years), amateur (24.9 ± 5.1 years), and recreational (25.6 ± 6.1 years) playing levels. Contact events from a sample of 30 matches filmed over seasons 2009-2010, 2010-2011, and 2011-2012 provided mean values for the frequency of contact events. The overall incidence for time-loss head injuries was 2.43 injuries per 1000 player match hours, with a higher incidence for the amateur (2.78; 95% CI, 2.37-3.20) compared with recreational (2.20; 95% CI, 1.86-2.53) ( P = .032) playing level but not different to the semiprofessional (2.31; 95% CI, 1.83-2.79) playing level. Concussion was the most common time-loss head injury, with 1.46 per 1000 player match hours. The tackle event was associated with 64% of all head injuries and 74% of all concussions. There was also a higher risk of injuries per tackle (0.33 per 1000 events; 95% CI, 0.30-0.37) compared with all other contact events. Concussion was the most common head injury diagnosis, although it is likely that this injury was underreported. Continuing education programs for medical staff and players are essential for the improved identification and management of

Soccer results affect subjective well-being, but only briefly: a smartphone study during the 2014 FIFA World Cup

PubMed Central

Stieger, Stefan; Götz, Friedrich M.; Gehrig, Fabienne

2015-01-01

The current research examined the effects of soccer match results on spectators’ subjective well-being. Across the group stage of the soccer World Cup 2014, German-speaking participants indicated their well-being three times per day through a smartphone-based science app. In line with proposed hypotheses, comparisons of data taken after the three matches of the German national team showed robust effects, revealing that well-being was higher among spectators than non-spectators, with effects increasing as a function of goal difference. Moreover, this gain in well-being was only found in spectators supporting the German soccer team, allowing us to rule out a general emotional contagion effect affecting all spectators. Although soccer results are associated with national identity and pride, their effects on subjective well-being were short-lived and only affected supporters. PMID:26029124

Nutritional guidance to soccer players for training and competition.

PubMed

Clark, K

1994-01-01

Strategies for a nutrition education as applied to individual soccer players provide a key to guiding them towards appropriate food selection. Scientific investigations have associated energy requirements, composition of the diet and carbohydrate intake with muscle glycogen storage, and adequacy of fluids with optimal athletic performance. In general, soccer players appear to consume adequate energy but low carbohydrate diets. The training diet should be comprised of 55-65% carbohydrate, 12-15% protein and less than 30% fat. The goal of the training diet is to provide adequate energy for weight maintenance, and 7-10 g of carbohydrate per kg body weight for maximizing glycogen storage. Nutritional needs for competition include eating prior to and after matches. Consumption of carbohydrate-rich foods for energy needs and glycogen resynthesis are key behaviours soccer players need to focus on daily. Qualified dietitians should be on hand to provide personal nutrition counselling, carbohydrate resource lists and education on food labels as simple and quick nutrition education strategies to guide soccer players, their parents, coaches and trainers towards improved food selections.

[Nurturing fair play in competitive sports. Results from a study on competitively oriented youth soccer].

PubMed

Pilz, G A

2005-08-01

Apologists of sports praise them as an ideal way to prevent addiction and violence. Sports critics see it rather as a socialization authority on the morals of the fair foul. This contradiction was investigated based on an examination of fairness behaviour and fairness education in youth soccer as well as the question of the connection between sports and violence and the preventive possibilities of sports. Our results point to differences in understanding fairness according to age, sex and primarily performance/success orientation. Teenagers learn al ready at the latest in the C youth that it is important and right in the interest of success to break rules. Thus it applies that the more distinctive the success orientation, the more in formal and formal fair play degenerate into fictitious action morals of competitive sport and make way for morals of the "fair foul". The coaches play an important, even quite obviously the central role as socialization agents. In stead of learning fairness, the opposite is often conveyed to many young people in the organizations. However, our examinations also show that coach es can positively influence both fairness understanding and fairness behaviour of young footballers. Coach es are thus challenged as role models to exemplify fair play by their own actions.

Kicks from the penalty mark in soccer: the roles of stress, skill, and fatigue for kick outcomes.

PubMed

Jordet, Geir; Hartman, Esther; Visscher, Chris; Lemmink, Koen A P M

2007-01-15

The soccer "penalty shootout" in the knock-out phase of major international tournaments is one of the most dramatic events in international soccer. The outcome of these kicks is typically attributed to factors such as psychology (e.g. coping with stress), skill (e.g. kicking technique), physiology (e.g. overcoming the fatigue of 120 min play), and chance (e.g. in what direction the goalkeeper moves). The purpose of this study was to use internet game record data to estimate the relative importance of these performance components for the outcome of penalty kicks in international matches. Data were collected from soccer statistics internet sites on all 41 penalty shootouts and 409 kicks taken in the World Cup, European Championships, and Copa America between 1976 and 2004. The results showed that the importance of the kicks (indicative of stress) was negatively related to the outcomes of the kicks, whereas skill and fatigue were less, or not, related to outcome. It was concluded that psychological components are most influential for the outcome of penalty kicks. We recommend that practitioners work with players to reduce the perceived importance of each kick.

Positional interchanges influence the physical and technical match performance variables of elite soccer players.

PubMed

Schuth, G; Carr, G; Barnes, C; Carling, C; Bradley, P S

2016-01-01

Positional variation in match performance is well established in elite soccer but no information exists on players switching positions. This study investigated the influence of elite players interchanging from one position to another on physical and technical match performance. Data were collected from multiple English Premier League (EPL) seasons using a computerised tracking system. After adhering to stringent inclusion criteria, players were examined across several interchanges: central-defender to fullback (CD-FB, n = 11, 312 observations), central-midfielder to wide-midfielder (CM-WM, n = 7, 171 observations), wide-midfielder to central-midfielder (WM-CM, n = 7, 197 observations) and attacker to wide-midfielder (AT-WM, n = 4, 81 observations). Players interchanging from CD-FB covered markedly more high-intensity running and sprinting distance (effect size [ES]: -1.56 and -1.26), lost more possessions but made more final third entries (ES: -1.23 and -1.55). Interchanging from CM-WM and WM-CM resulted in trivial to moderate differences in both physical (ES: -0.14-0.59 and -0.21-0.39) and technical performances (ES: -0.48-0.64 and -0.36-0.54). Players interchanging from AT-WM demonstrated a moderate difference in high-intensity running without possession (ES: -0.98) and moderate-to-large differences in the number of clearances, tackles and possessions won (ES: -0.77, -1.16 and -1.41). The data demonstrate that the physical and technical demands vary greatly from one interchange to another but utility players seem able to adapt to these positional switches.

The isokinetic strength profile of elite soccer players according to playing position

PubMed Central

Grygorowicz, Monika; Hojszyk, Radosław; Jadczak, Łukasz

2017-01-01

The aim of this study was to compare isokinetic strength performance profiles in elite soccer players across different field positions. A total of 111 elite international players of Polish Ekstraklasa (the top division in Poland) were examined during the 2010–2015 seasons. The players were classified into six positional roles: central defenders (CD), external defenders (ED), central midfielders (CM), external midfielders (EM), forwards (F), and goalkeepers (G). The concentric isokinetic strength (peak torque [PT] of quadriceps and hamstrings, H/Q ratios) was calculated for the dominant leg and the non-dominant leg at angular velocity of 1.05 rad ·s–1, whereas to assess isokinetic muscle endurance, the total work [TW] at angular velocity of 4.19 rad ·s–1, was taken into consideration. The results showed that isokinetic strength performance varies significantly among players in different playing positions. The analysis of PT for quadriceps (PT-Q) and hamstrings (PT-H) generally showed that the goalkeepers and central midfielders had lower strength levels compared to other playing positions. In the case of PT-H and hamstring/quadricep (H/Q) peak torque ratios, statistically significant differences were also noted for the legs, where mean values noted for the dominant leg were higher than for the non-dominant leg. For TW for quadriceps (TW-Q) and hamstrings (TW-H), statistically significant differences were noted only between playing positions. TW-Q values for goalkeepers were lower than for central defenders and external midfielders. TW-H values for goalkeepers were lower than for central midfielders, central defenders and external midfielders. This study showed that specific functional activity of players in individual positions on the field influences the varied profile of isokinetic strength performance. PMID:28759603

The isokinetic strength profile of elite soccer players according to playing position.

PubMed

Śliwowski, Robert; Grygorowicz, Monika; Hojszyk, Radosław; Jadczak, Łukasz

2017-01-01

The aim of this study was to compare isokinetic strength performance profiles in elite soccer players across different field positions. A total of 111 elite international players of Polish Ekstraklasa (the top division in Poland) were examined during the 2010-2015 seasons. The players were classified into six positional roles: central defenders (CD), external defenders (ED), central midfielders (CM), external midfielders (EM), forwards (F), and goalkeepers (G). The concentric isokinetic strength (peak torque [PT] of quadriceps and hamstrings, H/Q ratios) was calculated for the dominant leg and the non-dominant leg at angular velocity of 1.05 rad ·s-1, whereas to assess isokinetic muscle endurance, the total work [TW] at angular velocity of 4.19 rad ·s-1, was taken into consideration. The results showed that isokinetic strength performance varies significantly among players in different playing positions. The analysis of PT for quadriceps (PT-Q) and hamstrings (PT-H) generally showed that the goalkeepers and central midfielders had lower strength levels compared to other playing positions. In the case of PT-H and hamstring/quadricep (H/Q) peak torque ratios, statistically significant differences were also noted for the legs, where mean values noted for the dominant leg were higher than for the non-dominant leg. For TW for quadriceps (TW-Q) and hamstrings (TW-H), statistically significant differences were noted only between playing positions. TW-Q values for goalkeepers were lower than for central defenders and external midfielders. TW-H values for goalkeepers were lower than for central midfielders, central defenders and external midfielders. This study showed that specific functional activity of players in individual positions on the field influences the varied profile of isokinetic strength performance.

P-Soccer: Soccer Games Application using Kinect

NASA Astrophysics Data System (ADS)

Nasir, Mohamad Fahim Mohamed; Suparjoh, Suriawati; Razali, Nazim; Mustapha, Aida

2018-05-01

This paper presents a soccer game application called P-Soccer that uses Kinect as the interaction medium between users and the game characters. P-Soccer focuses on training penalty kicks with one character who is taking the kick. This game is developed based on the Game Development Life Cycle (GDLC) methodology. Results for alpha and beta testing showed that the target users are satisfied with overall game design and theme as well as the interactivity with the main character in the game.

Reducing muscle injuries and reinjuries in one italian professional male soccer team

PubMed Central

Melegati, Gianluca; Tornese, Davide; Gevi, Maurizio; Trabattoni, Alessandro; Pozzi, Grazia; Schonhuber, Herbert; Volpi, Piero

2013-01-01

Summary Background. The incidence rate of muscle injuries and re-injuries in professional elite soccer players actually is very high and may interfere with the fate of a championship. Purpose. To investigate the effect of a two-tiered injury prevention programme on first injury and re-injury incidence in top level male soccer players. Study design Case Series Study. Muscle injuries and re-injuries sustained by a group of 36 soccer player of an italian elite soccer team have been collected during 2010–2011 season. These data have been compared with those collected during the previous season in the same elite soccer team. Results. A total of 64 injuries occurred, 36 (56%) of which during practice and 28 (44%) during matches. Muscle injuries accounted for 31.3% of the total (n=20), 70% (n=14) of which occurred during practice and 30% (n=6) during matches. Hamstring were the muscles most often injured (n=11) In all, 3 re-injuries occurred (15% of muscle injuries). No early re-injuries occurred. The incidence was 2.5 injuries/1000 hours and the burden was 37 days absence/1000 hours. Conclusions. Through the implementation of a group and personalized injury prevention program, we were able to reduce the total number of muscle injuries and days absent because of injury, in a team of elite soccer players, as compared to the previous season. Specifically, muscle injuries accounted for 31% of all injuries, as compared to 59% of all injuries sustained by the team during the previous season. The number of injuries/1000 hours of exposure was reduced by half (from 5.6 to 2.5) and the days absent/1000 hours fell from 106 to 37. PMID:24596697

Soccer activity profile of altitude versus sea-level natives during acclimatisation to 3600 m (ISA3600)

PubMed Central

Aughey, Robert J; Hammond, Kristal; Varley, Matthew C; Schmidt, Walter F; Bourdon, Pitre C; Buchheit, Martin; Simpson, Ben; Garvican-Lewis, Laura A; Kley, Marlen; Soria, Rudy; Sargent, Charli; Roach, Gregory D; Claros, Jesus C Jimenez; Wachsmuth, Nadine; Gore, Christopher J

2013-01-01

Objectives We investigated the effect of high altitude on the match activity profile of elite youth high altitude and sea level residents. Methods Twenty Sea Level (Australian) and 19 Altitude-resident (Bolivian) soccer players played five games, two near sea level (430 m) and three in La Paz (3600 m). Match activity profile was quantified via global positioning system with the peak 5 min period for distance ((D5peak)) and high velocity running (>4.17 m/s, HIVR5peak); as well as the 5 min period immediately subsequent to the peak for both distance (D5sub) and high-velocity running (HIVR5sub) identified using a rolling 5 min epoch. The games at 3600 m were compared with the average of the two near sea-level games. Results The total distance per minute was reduced by a small magnitude in the first match at altitude in both teams, without any change in low-velocity running. There were variable changes in HiVR, D5peak and HiVR5peak from match to match for each team. There were within-team reductions in D5peak in each game at altitude compared with those at near sea level, and this reduction was greater by a small magnitude in Australians than Bolivians in game 4. The effect of altitude on HiVR5peak was moderately lower in Australians compared with Bolivians in game 3. There was no clear difference in the effect of altitude on maximal accelerations between teams. Conclusions High altitude reduces the distance covered by elite youth soccer players during matches. Neither 13 days of acclimatisation nor lifelong residence at high altitude protects against detrimental effects of altitude on match activity profile. PMID:24282196

Biology and medicine of soccer: an update.

PubMed

Shephard, R J

1999-10-01

Recent literature on the biology and medicine of soccer (primarily since 1990) has been accumulated by a combination of computer searching of relevant databases and review of the author's extensive files. From a total of 9681 papers, 540 were selected for closer scrutiny and 370 are discussed in the present review. These articles cover patterns of play and the resulting energy demands, the nutritional requirements of soccer, the anthropometric, physiological, biochemical and immunological characteristics of successful players, the influence of environmental stressors (heat, cold, hypoxia and time zone shifts), special features of female and junior competitors, selected issues in training, and the incidence and prevention of injuries. The information presented has important implications for the safety and success of soccer players; the challenge is now to ensure that this information is understood and acted upon by coaches and individual team members.

The Importance of Vitaminsfor Soccer Players.

PubMed

Eskici, Günay

2015-12-01

Soccer is one of the most widely played and complex sports in the world, where success depends on technical, tactical and physical skills of the players. Studies to improve performance in soccer have often focused on technique and tactics. However, nutrition is one of the most important factors influencing athletic performance of the players. The duration of matches is long and the training is intense. This leads to increased requirements for energy and nutrients, as well as increased reactive oxygen radicals and hence increased muscle damage. Vitamins are micronutrients that a living organism requires in trace quantities for health. As these assume crucial functions in the body, the performance of the player is negatively affected particularly during long-term deficiency. Beta-carotene, C and E vitamins are antioxidants that protect against oxygen radicals. In case of their deficiency, oxidative stress and muscle fatigue increases. Vitamin D is involved in maintaining mineral balance, and it increases absorption of dietary calcium and phosphorus. In case of vitamin D deficiency, injuries resulting from the musculoskeletal system might increase. B Vitamins (B1, B2, niacin, B6, B12, biotin, folic acid and pantothenic acid) perform duties such as energy production, absorption and transport of iron and blood cell production. Athletes who follow an energy-restricted and imbalanced diet might develop vitamin deficiency. In such a case, supplements can be used as recommended by the doctor/dietician. It is further reported that supplement use by athletes who have an adequate and balanced nutrition does not increase performance.

Robot soccer anywhere: achieving persistent autonomous navigation, mapping, and object vision tracking in dynamic environments

NASA Astrophysics Data System (ADS)

Dragone, Mauro; O'Donoghue, Ruadhan; Leonard, John J.; O'Hare, Gregory; Duffy, Brian; Patrikalakis, Andrew; Leederkerken, Jacques

2005-06-01

The paper describes an ongoing effort to enable autonomous mobile robots to play soccer in unstructured, everyday environments. Unlike conventional robot soccer competitions that are usually held on purpose-built robot soccer "fields", in our work we seek to develop the capability for robots to demonstrate aspects of soccer-playing in more diverse environments, such as schools, hospitals, or shopping malls, with static obstacles (furniture) and dynamic natural obstacles (people). This problem of "Soccer Anywhere" presents numerous research challenges including: (1) Simultaneous Localization and Mapping (SLAM) in dynamic, unstructured environments, (2) software control architectures for decentralized, distributed control of mobile agents, (3) integration of vision-based object tracking with dynamic control, and (4) social interaction with human participants. In addition to the intrinsic research merit of these topics, we believe that this capability would prove useful for outreach activities, in demonstrating robotics technology to primary and secondary school students, to motivate them to pursue careers in science and engineering.

The diagnostic and prognostic value of ultrasonography in soccer players with acute hamstring injuries.

PubMed

Petersen, Jesper; Thorborg, Kristian; Nielsen, Michael Bachmann; Skjødt, Thomas; Bolvig, Lars; Bang, Niels; Hölmich, Per

2014-02-01

An injury to the hamstring muscle complex is the most common injury in soccer. Ultrasound of acute hamstring injuries is often used as a clinical tool for diagnosing hamstring injuries and guiding players in when they can return to play. To (1) investigate the characteristic sonographic findings of acute hamstring injuries in soccer players, (2) compare the mean injury severity (time to return to play) in injured players with and without sonographically verified abnormalities, and (3) correlate the length of the injured area and absence from soccer play (time to return to play) to investigate if ultrasonography can be used as a prognostic indicator of time to return to play. Case series; Level of evidence, 4. Players from 50 teams participating in 1 of the top 5 Danish soccer divisions were followed in the period from January to December 2008. Of 67 players with acute hamstring injuries, 51 underwent ultrasonographic examination of the injured thigh and were included in this study. Ultrasonographic examinations were performed 1 to 10 days after injury (mean, 5.2 ± 3.0 days), and sonographic findings were present in 31 of 51 cases (61%). Two thirds of the injuries were to the biceps femoris muscle and one third to the semitendinosus muscle. No total ruptures were documented. The 51 acute hamstring injuries resulted in absence from soccer of a mean 25.4 ± 15.7 days per injury, with no significant difference between players with and without sonographically verified abnormalities (P = .41). No correlation existed between the length of the injured area and injury severity (r = 0.19, P = .29). The biceps femoris is the most commonly injured hamstring muscle detected by ultrasound, and more than half of the injuries are intramuscular. Because neither the presence of sonographic findings nor the size of the findings was correlated with time to return to play in injured soccer players, the prognosis of hamstring injuries should not be guided by these findings alone.

Squad management, injury and match performance in a professional soccer team over a championship-winning season.

PubMed

Carling, Christopher; Le Gall, Franck; McCall, Alan; Nédélec, Mathieu; Dupont, Gregory

2015-01-01

Squad management, injury and physical, tactical and technical match performance were investigated in a professional soccer team across five consecutive league seasons (2008-2013, 190 league games) with specific focus on a championship-winning season (2010/11). For each player, match participation and time-loss injuries were recorded, the latter prospectively diagnosed by the team's physician. Defending and attacking tactical and technical performance indicators investigated included ball possession and possession in opponents' half, passes, forward passes, completed passes and forward passes, crosses and completed crosses, goal attempts and goal attempts on target, successful final third entries, free-kicks and 50/50 duels won/lost. Physical performance measures included total distance and distance covered at high-speeds (≥19.1 km/h). Results showed that during the 2010/11 season, squad utilisation was lowest potentially owing to the observed lower match injury occurrence and working days lost to injury thereby increasing player availability. In 2010/11, the team won both its highest number of points and conceded its lowest number of goals especially over the second half of this season. The team also won its highest number of games directly via a goal from a substitute and scored and conceded a goal first on the highest and lowest number of occasions, respectively. While multivariate analysis of variance (MANOVA) detected a significant difference in some attacking and defensive performance indicators across the five seasons, these were generally not distinguishing factors in 2010/11. Similarly, univariate ANOVAs showed a significant difference in running distances covered across seasons, but the trend was for less activity in 2010/11.

Nutrient intake and food habits of soccer players: analyzing the correlates of eating practice.

PubMed

García-Rovés, Pablo M; García-Zapico, Pedro; Patterson, Angeles M; Iglesias-Gutiérrez, Eduardo

2014-07-18

Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player's career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.

Nutrient Intake and Food Habits of Soccer Players: Analyzing the Correlates of Eating Practice

PubMed Central

García-Rovés, Pablo M.; García-Zapico, Pedro; Patterson, Ángeles M.; Iglesias-Gutiérrez, Eduardo

2014-01-01

Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player’s career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players. PMID:25045939

Academic performance and self-regulatory skills in elite youth soccer players.

PubMed

Jonker, Laura; Elferink-Gemser, Marije T; Toering, Tynke T; Lyons, James; Visscher, Chris

2010-12-01

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12-16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.

Leadership Power Perceptions of Soccer Coaches and Soccer Players According to Their Education

PubMed Central

Konter, Erkut

2012-01-01

The purpose of this study was to analyze the leadership power perceptions of soccer coaches and soccer players according to their educational levels. Data were collected from 165 male soccer coaches and 870 male soccer players. Adapted versions of the “Power in Soccer Questionnaire-Other”, the “Power in Soccer Questionnaire-Self” and an “information form” were used for data collection, and collected data were analyzed by the Kruskal-Wallis and the Mann-Whitney Tests. Analysis of the Power in Soccer Questionnaire-Other revealed significant differences between soccer players’ level of education and their perception of Coercive Power (p<.003), and no significant differences related to Referent Power, Legitimate Power and Expert Power. Analysis of the Power in Soccer Questionnaire-Self also revealed the only significant difference between coaches’ level of education and their perception of Legitimate Power (p<.001), and no significant differences with regard to others. Different perception of leadership powers between coaches and players might create communication and performance problems in soccer. PMID:23486640

Body image and body composition: comparisons of young male elite soccer players and controls.

PubMed

Arroyo, Marta; Gonzalez-de-Suso, Jose Manuel; Sanchez, Celia; Ansotegui, Laura; Rocandio, Ana M

2008-12-01

The purpose of this study was to evaluate body composition and body image (perception and satisfaction) in a group of young elite soccer players and to compare the data with those of a control group (age and BMI matched). Participants were 56 volunteer males whose mean age and BMI were 19.6 (SD 1.3) years and 23.3 (SD 1.1) kg/m2, respectively. Results showed that soccer players have a higher lean mass and lower fat mass than controls. Moreover, body perception (difference between current and actual image) was more accurate in controls than in soccer players, and the results suggest a tendency for soccer players to aspire to have more muscle mass and body fat. Soccer players perceived an ideal image with significantly higher body-fat percentage than their current and actual images. There were no body-dissatisfaction differences between groups, however. Although the results are necessarily limited by the small sample size, the findings should be of interest to coaches of young elite soccer teams.

Comparison of the Physical and Technical Demands of Cricket Players During Training and Match-Play.

PubMed

Vickery, Will; Duffield, Rob; Crowther, Rian; Beakley, David; Blanch, Peter; Dascombe, Ben J

2018-03-01

Vickery, W, Duffield, R, Crowther, R, Beakley, D, Blanch, P, and Dascombe, BJ. Comparison of the physical and technical demands of cricket players during training and match-play. J Strength Cond Res 32(3): 821-829, 2018-This study aimed to determine which training method (net-based sessions or center-wicket simulations) currently used in national level and U19 male players cricket provided a more physical and technical match-specific training response. The heart rate, rating of perceived exertion, and movement patterns of 42 male cricket players were measured across the various training and match formats. Video analysis was coded retrospectively to quantify technical loads based on the cricket skills performed. Magnitude-based inferences were based on the standardization of effect and presented with ±90% confidence intervals. Regardless of playing position, differences in physiological demands between training modes and match-play were unclear, with the exception of higher heart rates in fielders during traditional net sessions (mean heart rate: d = -2.7 [-4.7 to -0.7]; 75% of maximum heart rate: d = -1.7 [-3.2 to -0.2]). Typically, the movement demands of center-wicket simulations were similar or greater than match-play, which was most evident in the distance traveled at a high intensity within each playing position (batsmen: d = 6.4 [3.7-9.2]; medium-fast bowlers: d = 1.71 [0.1-3.3]; spin bowlers: d = 6.5 [0.01-13.0]; fielders: d = 0.8 [-0.2 to 1.7]). The technical demands of traditional net cricket training exceeded that of a typical match for each playing position. Specifically, fast bowlers delivered a greater number of balls during net-bowling compared with a match (d = -2.2 [-3.6 to 0.9]). In conclusion, center-wicket simulations more closely matched the physical demands of a One-Day match within batsmen and spin bowlers, whereas traditional cricket training often exceeded match-specific demands.

A Comparison of the Perceptual and Technical Demands of Tennis Training, Simulated Match Play, and Competitive Tournaments.

PubMed

Murphy, Alistair P; Duffield, Rob; Kellett, Aaron; Reid, Machar

2016-01-01

High-performance tennis environments aim to prepare athletes for competitive demands through simulated-match scenarios and drills. With a dearth of direct comparisons between training and tournament demands, the current investigation compared the perceptual and technical characteristics of training drills, simulated match play, and tournament matches. Data were collected from 18 high-performance junior tennis players (gender: 10 male, 8 female; age 16 ± 1.1 y) during 6 ± 2 drill-based training sessions, 5 ± 2 simulated match-play sessions, and 5 ± 3 tournament matches from each participant. Tournament matches were further distinguished by win or loss and against seeded or nonseeded opponents. Notational analysis of stroke and error rates, winners, and serves, along with rating of perceived physical exertion (RPE) and mental exertion was measured postsession. Repeated-measures analyses of variance and effect-size analysis revealed that training sessions were significantly shorter in duration than tournament matches (P < .05, d = 1.18). RPEs during training and simulated match-play sessions were lower than in tournaments (P > .05; d = 1.26, d = 1.05, respectively). Mental exertion in training was lower than in both simulated match play and tournaments (P > .05; d = 1.10, d = 0.86, respectively). Stroke rates during tournaments exceeded those observed in training (P < .05, d = 3.41) and simulated-match-play (P < .05, d = 1.22) sessions. Furthermore, the serve was used more during tournaments than simulated match play (P < .05, d = 4.28), while errors and winners were similar independent of setting (P > .05, d < 0.80). Training in the form of drills or simulated match play appeared to inadequately replicate tournament demands in this cohort of players. Coaches should be mindful of match demands to best prescribe sessions of relevant duration, as well as internal (RPE) and technical (stroke rate) load, to aid tournament preparation.

Soccer and Sudden Cardiac Death in Young Competitive Athletes: A Review

PubMed Central

Higgins, John P.; Andino, Aldo

2013-01-01

Sudden cardiac death (SCD) in young competitive athletes (<35 years old) is a tragic event that has been brought to public attention in the past few decades. The incidence of SCD is reported to be 1-2/100,000 per year, with athletes at a 2.5 times higher risk. Soccer is the most popular sport in the world, played by people of all ages. However, unfortunately it is cardiovascular diseases such as hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy that have subtly missed screening and claimed the lives of soccer stars such as Marc Vivien Foe and Antonio Puerta during live action on the field and on an internationally televised stage. This paper covers the physiological demands of soccer and the relationship between soccer and SCD. It also reviews the most common causes of SCD in young athletes, discusses the current guidelines in place by The Fédération Internationale de Football Association (FIFA) for screening among professional soccer players, and the precautions that have been put in place to prevent SCD on the field in professional soccer. PMID:26464886

The metabolic power and energetic demands of elite Gaelic football match play.

PubMed

Malone, Shane; Solan, Barry; Collins, Kieran; Doran, Dominic

2017-05-01

Metabolic power has not yet been investigated within elite Gaelic football. The aim of the current investigation was to compare the metabolic power demands between positional groups and examine the temporal profile of elite Gaelic football match play. Global positional satellite system (GPS) data were collected from 50 elite Gaelic football players from 4 inter-county teams during 35 elite competitive matches over a three season period. A total of 351 complete match samples were obtained for final analysis. Players were categorized based on positional groups; full-back, half-back, midfield, half-forward and full-forward. Instantaneous raw velocity data was obtained from the GPS and exported to a customized spreadsheet which provided estimations of both speed based, derived metabolic power and energy expenditure variables (total distance, high speed distance, average metabolic power, high power distance and total energy expenditure). Match mean distance was 9222±1588 m, reflective of an average metabolic power of 9.5-12.5 W·kg-1, with an average energy expenditure of 58-70 Kj·kg-1 depending on position. There were significant differences between positional groups for both speed-based and metabolic power indices. Midfielders covered more total and high-speed distance, as well as greater average and overall energy expenditure compared to other positions (P<0.001). A reduction in total, high-speed, and high-power distance, as well as average metabolic power throughout the match (P<0.001) was observed. Positional differences exist for both metabolic power and traditional running based variables. The middle three positions (midfield, half-back and half-forward) possess greater activity profiles when compared to other positional groups. The reduction in metabolic power and traditional running based variables are comparable across match play. The current study demonstrates that metabolic power may contribute to our understanding of Gaelic football match-play.

Injury profile of a professional soccer team in the premier league of iran.

PubMed

Hassabi, Mohammad; Mohammad-Javad Mortazavi, Seyed; Giti, Mohammad-Reza; Hassabi, Majid; Mansournia, Mohammad-Ali; Shapouran, Sara

2010-12-01

Despite numerous studies which have been done regarding soccer injuries worldwide, there is lack of available data considering the epidemiology of injuries in the Iranian soccer premier league, although it is the most popular sport in the country. The main goal of this research was to determine the incidence of physical injuries in the studied population, considering other characteristics such as site, type and mechanism as well. Twenty one adult male professional soccer players (age 24±3), members of a team (Tehran-Pas) participating in Iranian premier league, were followed during a 4-month period. The injury characteristics and exposure times were recorded by the team physician during all the matches and training sessions. The total exposure time was 2610 playing hours (2352 h of training versus 258 h of competition). Eighty six percent of the injuries were acute. Incidence of acute injuries was 16.5 (95% CI: 12-22) per 1000 hours of playing (11.5 per 1000 hrs of training and 62 per 1000 hrs of competition). The most common types of injuries were strains followed by contusions, each of which constituted 30% of acute injuries. More than 80% of injuries occurred in lower limbs, especially in thigh and groin regions. Nearly 60% of acute injuries occurred in dominant side of the body, and collision was the reason of about half of the acute injuries. Severity of more than 70% of the injuries was minor. On average each injury had led the player being off the field for about 10 days. The incidence of injury in this research is in range of numbers obtained in important international tournaments but the rate of injuries during training sessions is higher than comparable studies.

Acceleratory match-play demands of a Super Rugby team over a competitive season.

PubMed

Owen, Shaun M; Venter, Rachel E; du Toit, Stephan; Kraak, Wilbur J

2015-01-01

The match-play demands of rugby union have increased over time, and these demands should be quantified so as to provide a basis for optimal player loading during training. The primary aim of this article was to quantify accelerations, decelerations, impacts and aggregated body demands during the first half of match-play in a Super Rugby team. The secondary aim was to determine whether these characteristics are position-specific. Thirty-three players were monitored for 14 matches using global positioning system units with inbuilt microtechnology. Players were grouped according to positional roles and data were analysed for those who completed the entire duration of the first half of a given match. Forwards sustained more (d = 0.44) high-intensity impacts and greater (d = 0.26) aggregated body demands, while backs had more moderate (d = 0.55) and heavy accelerations (d = 0.76), and moderate (d = 0.23) and heavy decelerations (d = 0.54). These differences suggest that conditioning and recovery strategies should reflect the physical demands placed on players in different playing positions. Forwards should be conditioned with a focus on impacts and require longer recovery for the same duration of playing time, whereas conditioning for backs should emphasise rapid accelerations and decelerations.

Individual ball possession in soccer

PubMed Central

Hoernig, Martin

2017-01-01

This paper describes models for detecting individual and team ball possession in soccer based on position data. The types of ball possession are classified as Individual Ball Possession (IBC), Individual Ball Action (IBA), Individual Ball Control (IBC), Team Ball Possession (TBP), Team Ball Control (TBC) und Team Playmaking (TPM) according to different starting points and endpoints and the type of ball control involved. The machine learning approach used is able to determine how long the ball spends in the sphere of influence of a player based on the distance between the players and the ball together with their direction of motion, speed and the acceleration of the ball. The degree of ball control exhibited during this phase is classified based on the spatio-temporal configuration of the player controlling the ball, the ball itself and opposing players using a Bayesian network. The evaluation and application of this approach uses data from 60 matches in the German Bundesliga season of 2013/14, including 69,667 IBA intervals. The identification rate was F = .88 for IBA and F = .83 for IBP, and the classification rate for IBC was κ = .67. Match analysis showed the following mean values per match: TBP 56:04 ± 5:12 min, TPM 50:01 ± 7:05 min and TBC 17:49 ± 8:13 min. There were 836 ± 424 IBC intervals per match and their number was significantly reduced by -5.1% from the 1st to 2nd half. The analysis of ball possession at the player level indicates shortest accumulated IBC times for the central forwards (0:49 ± 0:43 min) and the longest for goalkeepers (1:38 ± 0:58 min), central defenders (1:38 ± 1:09 min) and central midfielders (1:27 ± 1:08 min). The results could improve performance analysis in soccer, help to detect match events automatically, and allow discernment of higher value tactical structures, which is based on individual ball possession. PMID:28692649

Pacing behaviour of players in team sports: Influence of match status manipulation and task duration knowledge

PubMed Central

Ferraz, Ricardo; Gonçalves, Bruno; Marinho, Daniel A.; Sampaio, Jaime; Marques, Mário C.

2018-01-01

The study aimed to identify the influence of prior knowledge of exercise duration associated with initial information about momentary match status (losing or winning) on the pacing behaviour displayed during soccer game-based activities. Twenty semi-professional male players participated in four game scenarios divided in two sessions. In the first game scenario, players were not informed about the time duration or initial match status. In the second, players were only informed they would be required to play a small-sided game for 12 minutes. In the third, players were told they would play a small-sided game for 12 minutes and that one of the teams was winning 2 to 0. Finally, in the fourth game scenario, players were instructed they would play a small-sided game for 12 minutes and the score lines used at the start of the previous game scenario were reversed. The results showed a tendency for the unknown task duration to elicit greater physical responses in all studied variables, compared with knowing the task duration. Knowing the task duration and starting the game winning or losing did not affect the players’ activity profile between the two conditions. Thus, during small-sided soccer games, knowledge (or not) about the exercise duration alters the pacing behaviour of the players. Moreover, short and undisclosed-length exercise durations resulted in the adoption of more aggressive pacing strategies, characterised by higher initial exercise intensities. Furthermore, previous information on match status does not seem to interfere with pacing patterns if the players are aware of the exercise duration. Coaches may use knowledge of exercise duration to manipulate the small-sided games’ demands. PMID:29401476

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.

PubMed

Anderson, Liam; Orme, Patrick; Di Michele, Rocco; Close, Graeme L; Morgans, Ryland; Drust, Barry; Morton, James P

2016-01-01

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.

Girls' soccer performance and motivation: games vs technique approach.

PubMed

Chatzopoulos, Dimitris; Drakou, Amalia; Kotzamanidou, Marina; Tsorbatzoudis, Haralambos

2006-10-01

The purpose of this study was to investigate the effects of the Technique and Games approaches on girls' soccer performance and motivation. The Technique approach focuses on technique instruction using drills, whereas the Games approach places emphasis on tactic instruction with modified games. 37 girls, 12 to 13 years old, were taught 15 soccer lessons by the Technique approach and 35 girls by the Games approach. At the beginning and at the end of the research soccer matches were videotaped and evaluated by Oslin, Mitchell, and Griffin's Game Performance Assessment Instrument. Girls' motivation was assessed on the Intrinsic Motivation Inventory. The Games group had significantly better scores after training on tactical behaviour and intrinsic motivation than the Technique group. There were no significant differences in skill execution between groups trained under the two approaches. Considering the importance of intrinsic motivation for a lifelong, physically active lifestyle, researchers could focus study on the approaches and girls' motivation.

Application of the Copenhagen Soccer Test in high-level women players - locomotor activities, physiological response and sprint performance.

PubMed

Bendiksen, Mads; Pettersen, Svein Arne; Ingebrigtsen, Jørgen; Randers, Morten B; Brito, João; Mohr, Magni; Bangsbo, Jens; Krustrup, Peter

2013-12-01

We evaluated the physiological response, sprint performance and technical ability in various phases of the Copenhagen Soccer Test for Women (CSTw) and investigated whether the locomotor activities of the CSTw were comparable to competitive match-play (CM). Physiological measurements and physical/technical assessments were performed during CSTw for eleven Norwegian high-level women soccer players. The activity pattern during CSTw and CM was monitored using the ZXY tracking system. No differences were observed between CSTw and CM with regards to total distance covered (10093±94 and 9674±191m), high intensity running (1278±67 and 1193±115m) or sprinting (422±55 and 372±46m) (p>.05). During CSTw, average HR was 85±2%HRmax with 35±2% playing time >90%HRmax. Blood lactate increased (p<.05) from 1.4±0.3mM at rest to an average of 4.7±0.5mM during CSTw, with no changes during the test. Blood glucose was 5.4±0.3mM at rest and remained unaltered during CSTw. Sprint performance (2×20m) decreased (p<.05) by 3% during CSTw (8.19±0.06-8.47±0.10s). In conclusion, the locomotor activities during CSTw were comparable to that of high-level competitive match-play. The physiological demands of the CSTw were high, with no changes in heart rate, blood lactate or technical performance during the test, but a lowered sprint performance towards the end of the test. Copyright © 2013 Elsevier B.V. All rights reserved.

Differences in injury risk and characteristics between Dutch amateur and professional soccer players.

PubMed

van Beijsterveldt, A M C Anne-Marie; Stubbe, J H; Schmikli, S L; van de Port, I G L; Backx, F J G

2015-03-01

To compare the incidence and characteristics of injuries between Dutch amateur and professional male soccer players during one entire competition season. A prospective two-cohort design. During the 2009-2010 season, 456 Dutch male amateur soccer players and 217 professional players were prospectively followed. Information on injuries and individual exposure to all soccer activities were recorded in both cohorts. Injuries were recorded using the time-loss definition. In total, 424 injuries were recorded among 274 of the amateur players (60.1% injured players) and 286 injuries were sustained by 136 (62.7% injured players) of the professional players (p=0.52). Compared to the professionals, the injury incidence during training sessions was higher among amateurs (p=0.01), but the injury incidence among professionals was higher during matches (p<0.001). Professional players also had a higher incidence of minimal injuries (p<0.001), whereas the incidence of moderate and severe injuries was higher for amateurs (all p<0.001). Lastly, professional players sustained more overuse injuries (p=0.02), whereas amateurs reported more recurrent injuries (p<0.001). The above-mentioned differences in injury rates between amateur and professional players in the Netherlands might be explained by the difference in the level at which they play, since factors like the availability of medical support and/or the team size may influence the injury risk and characteristics. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Goal Format in Small-Sided Soccer Games: Technical Actions and Offensive Scenarios of Prepubescent Players

PubMed Central

Pulling, Craig; Twitchen, Alex; Pettefer, Carl

2016-01-01

The aim of this study was to investigate the influence of the number of goal-posts and the positioning of goal-posts used within small-sided games on the frequency of technical actions and offensive scenarios performed by prepubescent players within soccer. The participants were eight male prepubescent soccer players (12.1 ± 0.5 years). The participants were video recorded for 20 min playing four different formats of 4v4 small-sided games: (1) standard two goal game; (2) four goal game, one goal in each corner; (3) two goal game with goal-posts positioned 9.14 m/10 yd infield, scoring only through the back of the goal; (4) four goal-game, one goal positioned 9.14 m/10 yd infield in each corner, scoring through either the front or back of each goal. Chi-squared tests of independence were utilized to statistically explore the impact of the different small-sided game formats. There were significant associations (p < 0.05) observed between the different small-sided game formats and the frequency of turns, dribbles, shots, goals and overlaps performed. For example, players performed more turns in small-sided game format two and more shots during small-sided game format four. It is suggested coaches should consider using a variation of the number and positioning of goal-posts in small-sided games as an effective training tool in the development of prepubescent soccer players. This will enable coaches to vary the focus of sessions, and develop specific technical and tactical actions within a situation similar to that of real match-play. PMID:29910301

Testosterone and cortisol responses in male soccer players: The effect of home and away venues.

PubMed

Fothergill, Melissa; Wolfson, Sandy; Neave, Nick

2017-08-01

The present studies examined the influence of playing venue on psychobiological responses in male soccer players. Many studies have demonstrated the existence of a home advantage, wherein teams perform better at home than away. A recent focus has attempted to explain this advantage from a psychobiological perspective, with studies showing hormonal differences with regard to venue, game outcome, dominance and perceived stress. Two studies investigated testosterone and cortisol responses in relation to home and away venues. In an initial study of 18 male elite Premier League academy soccer players (age, 17.47, SD, 64), salivary cortisol levels were monitored in two competitive matches, both at home and away. Higher post-game cortisol levels were observed at home (p=0.002), with the team winning all its games. In a second study involving a 12 semi-professional group of players (age, 23.17, SD, 3.8), the same post-game cortisol findings at home were replicated (p=0.001), with this team losing all its games. No effects were observed for testosterone in either study. The results extend earlier research findings on the complex relationship which surrounds the psychobiological impact on the home advantage. The findings suggest that higher levels of stress are experienced by home players in their home matches. Copyright © 2017 Elsevier Inc. All rights reserved.

Bridging the gap between empirical results, actual strategies, and developmental programs in soccer.

PubMed

Figueiredo, António J; Gonçalves, Carlos E; Tessitore, Antonio

2014-05-01

Being one of the most prominent globalized sports, soccer played at club, national, and continental levels has a relevant societal role. At present, the specific competencies, interests, and languages of the different actors involved in the selection, development, and support of long-lasting careers of players might limit opportunities for potential talented players. Unless the cultural environment of soccer resolves the gaps between empirical results and actual soccer strategies, scientific discussion relating to the effectiveness of talent selection and development remains limited. This commentary is intended to highlight the need for developmental programs to prepare soccer personnel for a transdisciplinary dialogue, which could foster a future development of this sport. Finally, in considering the wide soccer-related employment opportunities at local, national, and international levels, the need for a clear qualification framework is crucial.

Influence of Playing a Prolonged Tennis Match on Shoulder Internal Range of Motion.

PubMed

Martin, Caroline; Kulpa, Richard; Ezanno, Felix; Delamarche, Paul; Bideau, Benoit

2016-08-01

Shoulder range of motion (ROM) deficits have been identified as an injury risk factor among tennis players. It is well known that shoulder internal rotation deficit increases with age and years of play, but there is a lack of knowledge regarding the influence of a prolonged tennis match on shoulder ROM. To examine changes in shoulder ROM during a prolonged tennis match. Descriptive laboratory study. Shoulder passive internal and external rotation ROM were measured on 8 male tennis players before, every 30 minutes during, and just after a 3-hour tennis match. Total ROM was calculated as the combination of shoulder internal and external rotations. Ball velocity on the serve was measured with a radar gun before, at midmatch, and just after the match. Decreases in shoulder internal rotation (-20.8°; P = .005), total ROM (-24.6°; P = .001), and serve velocity (-1.8 m/s; P = .002) were observed at the end of the match. No statistically significant difference was observed for shoulder external rotation after the match (P = .460). Passive shoulder internal rotation and total ROM are significantly decreased during a 3-hour tennis match. The results show that a prolonged tennis match play can modify values of shoulder ROM. © 2016 The Author(s).

Relation between social cohesion and team performance in soccer teams.

PubMed

Tziner, Aharon; Nicola, Nicola; Rizac, Anis

2003-02-01

Investigations of the influence on team performance of team composition, in terms of task-related attributes, e.g., personality traits, cognitive abilities, often assumes this relation to be mediated by the strength (intensity) of the interpersonal relations (social cohesion) among team members. However, there has been little empirical examination of how much social cohesion actually affects team outcomes. This preliminary study sought to examine this issue using soccer teams, which have been held to resemble workplace teams. Perceptions of team cohesion were collected from 198 Israeli soccer players (comprising 36 national league teams) during the week preceding their weekly games. A significant correlation was found between the perceptions of social cohesion and the results of the soccer matches, indicating a link between team social cohesion and team performance. Implications of the results, as well as the study's limitations, are discussed, and avenues for research are suggested.

Cryotherapy Reinvented: Application of Phase Change Material for Recovery in Elite Soccer.

PubMed

Clifford, Tom; Abbott, Will; Kwiecien, Susan Y; Howatson, Glyn; McHugh, Malachy P

2018-05-01

To examine whether donning lower-body garments fitted with cooled phase change material (PCM) would enhance recovery after a soccer match. In a randomized, crossover design, 11 elite soccer players from the reserve squad of a team in the second-highest league in England wore PCM cooled to 15°C (PCM cold ) or left at ambient temperature (PCM amb ; sham control) for 3 h after a soccer match. To assess recovery, countermovement jump height, maximal isometric voluntary contraction (MIVC), muscle soreness, and the adapted Brief Assessment of Mood Questionnaire (BAM+) were measured before 12, 36, and 60 h after each match. A belief questionnaire was completed preintervention and postintervention to determine the perceived effectiveness of each garment. Results are comparisons between the 2 conditions at each time point postmatch. MIVC at 36 h postmatch was greater with PCM cold versus PCM warm (P = .01; ES = 1.59; 95% CI, 3.9-17.1%). MIVC also tended to be higher at 60 h postmatch (P = .05; ES = 0.85; 95% CI, -0.4% to 11.1%). Muscle soreness was 26.5% lower in PCM cold versus PCM warm at 36 h (P = .02; ES = 1.7; 95% CI, -50.4 to -16.1 mm) and 24.3% lower at 60 h (P = .04; ES = 1.1; 95% CI, -26.9 to -0.874 mm). There were no between-conditions differences in postmatch countermovement jump height or BAM+ (P > .05). The belief questionnaire revealed that players felt the PCM cold was more effective than the PCM amb after the intervention (P = .004). PCM cooling garments provide a practical means of delivering prolonged postexercise cooling and thereby accelerate recovery in elite soccer players.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, and NASA astronaut Steve Swanson, commander, gather around a computer in the Unity node of the International Space Station after the German-USA soccer match.

The expected value of possession in professional rugby league match-play.

PubMed

Kempton, Thomas; Kennedy, Nicholas; Coutts, Aaron J

2016-01-01

This study estimated the expected point value for starting possessions in different field locations during rugby league match-play and calculated the mean expected points for each subsequent play during the possession. It also examined the origin of tries scored according to the method of gaining possession. Play-by-play data were taken from all 768 regular-season National Rugby League (NRL) matches during 2010-2013. A probabilistic model estimated the expected point outcome based on the net difference in points scored by a team in possession in a given situation. An iterative method was used to approximate the value of each situation based on actual scoring outcomes. Possessions commencing close to the opposition's goal-line had the highest expected point equity, which decreased as the location of the possession moved towards the team's own goal-line. Possessions following an opposition error, penalty or goal-line dropout had the highest likelihood of a try being scored on the set subsequent to their occurrence. In contrast, possessions that follow an opposition completed set or a restart were least likely to result in a try. The expected point values framework from our model has applications for informing playing strategy and assessing individual and team performance in professional rugby league.

Intergroup relations in soccer finals: people's forecasts of the duration of emotional reactions of in-group and out-group soccer fans.

PubMed

Gaunt, Ruth; Sindic, Denis; Leyens, Jacques-Philippe

2005-04-01

The authors examined the hypothesis that people forecast a longer duration of uniquely human secondary emotions for their in-group than for an out-group. The authors conducted a field experiment in the setting of the European soccer championship. They asked Belgian participants to forecast the intensity with which their in-group Belgian fans or the out-group Turkish fans would experience various primary and secondary emotions in response to their team's victory or loss immediately after the Turkey-Belgium match and three days later. The results support the hypothesis. Moreover, and as the authors expected, they found no differences in the participants' forecasts of primary emotions. The authors discussed the implications of these findings for intergroup relations in general and for soccer fans' behavior in particular.

ACL injury risk in elite female youth soccer: Changes in neuromuscular control of the knee following soccer-specific fatigue.

PubMed

De Ste Croix, M B A; Priestley, A M; Lloyd, R S; Oliver, J L

2015-10-01

Fatigue is known to influence dynamic knee joint stability from a neuromuscular perspective, and electromechanical delay (EMD) plays an important role as the feedback activation mechanism that stabilizes the joint. The aim of this study was to investigate the influence of soccer-specific fatigue on EMD in U13-, U15-, and U17-year-old female soccer players. Thirty-six youth soccer players performed eccentric actions of the hamstrings in a prone position at 60, 120, and 180°/s before and after a soccer-specific fatigue trial. Surface electromyography was used to determine EMD from the semitendinosus, biceps femoris and gastrocnemius. A time × age × muscle × velocity repeated measures analysis of variance was used to explore the influence of fatigue on EMD. A significant main effect for time (P = 0.001) indicated that EMD was significantly longer post- compared with pre-fatigue (58.4% increase). A significant time × group interaction effect (P = 0.046) indicated EMD was significantly longer in the U13 age group compared with the U15 (P = 0.011) and U17 (P = 0.021) groups and greater post-fatigue. Soccer-specific fatigue compromised neuromuscular feedback mechanisms and the age-related effects may represent a more compliant muscle-tendon system in younger compared with older girls, increasing risk of injury. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Exposure to hot and cold environmental conditions does not affect the decision making ability of soccer referees following an intermittent sprint protocol.

PubMed

Taylor, Lee; Fitch, Natalie; Castle, Paul; Watkins, Samuel; Aldous, Jeffrey; Sculthorpe, Nicholas; Midgely, Adrian; Brewer, John; Mauger, Alexis

2014-01-01

Soccer referees enforce the laws of the game and the decisions they make can directly affect match results. Fixtures within European competitions take place in climatic conditions that are often challenging (e.g., Moscow ~ -5°C, Madrid ~30°C). Effects of these temperatures on player performance are well-documented; however, little is known how this environmental stress may impair cognitive performance of soccer referees and if so, whether exercise exasperates this. The present study aims to investigate the effect of cold [COLD; -5°C, 40% relative humidity (RH)], hot (HOT; 30°C, 40% RH) and temperate (CONT; 18°C, 40% RH) conditions on decision making during soccer specific exercise. On separate occasions within each condition, 13 physically active males; either semi-professional referees or semi-professional soccer players completed three 90 min intermittent treadmill protocols that simulated match play, interspersed with 4 computer delivered cognitive tests to measure vigilance and dual task capacity. Core and skin temperature, heart rate, rating of perceived exertion (RPE) and thermal sensation (TS) were recorded throughout the protocol. There was no significant difference between conditions for decision making in either the dual task (interaction effects: FALSE p = 0.46; MISSED p = 0.72; TRACKING p = 0.22) or vigilance assessments (interaction effects: FALSE p = 0.31; HIT p = 0.15; MISSED p = 0.17) despite significant differences in measured physiological variables (skin temperature: HOT vs. CONT 95% CI = 2.6 to 3.9, p < 0.001; HOT vs. COLD 95% CI = 6.6 to 9.0, p < 0.001; CONT vs. COLD 95% CI = 3.4 to 5.7, p < 0.01). It is hypothesized that the lack of difference observed in decision making ability between conditions was due to the exercise protocol used, as it may not have elicited an appropriate and valid soccer specific internal load to alter cognitive functioning.

Nutritional Practices of National Female Soccer Players: Analysis and Recommendations

PubMed Central

Martin, Louise; Lambeth, Anneliese; Scott, Dawn

2006-01-01

The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day-1) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key points Female soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study. Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer players Fluid requirements should be addressed on an individual basis and matched to player requirements. The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV. PMID:24198690

Nutritional practices of national female soccer players: analysis and recommendations.

PubMed

Martin, Louise; Lambeth, Anneliese; Scott, Dawn

2006-01-01

The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day(-1)) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key pointsFemale soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study.Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer playersFluid requirements should be addressed on an individual basis and matched to player requirements.The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV.

Importance of Reactive Agility and Change of Direction Speed in Differentiating Performance Levels in Junior Soccer Players: Reliability and Validity of Newly Developed Soccer-Specific Tests

PubMed Central

Pojskic, Haris; Åslin, Erik; Krolo, Ante; Jukic, Ivan; Uljevic, Ognjen; Spasic, Miodrag; Sekulic, Damir

2018-01-01

Agility is a significant determinant of success in soccer; however, studies have rarely presented and evaluated soccer-specific tests of reactive agility (S_RAG) and non-reactive agility (change of direction speed – S_CODS) or their applicability in this sport. The aim of this study was to define the reliability and validity of newly developed tests of the S_RAG and S_CODS to discriminate between the performance levels of junior soccer players. The study consisted of 20 players who were involved at the highest national competitive rank (all males; age: 17.0 ± 0.9 years), divided into three playing positions (defenders, midfielders, and forwards) and two performance levels (U17 and U19). Variables included body mass (BM), body height, body fat percentage, 20-m sprint, squat jump, countermovement jump, reactive-strength-index, unilateral jump, 1RM-back-squat, S_CODS, and three protocols of S_RAG. The reliabilities of the S_RAG and S_CODS were appropriate to high (ICC: 0.70 to 0.92), with the strongest reliability evidenced for the S_CODS. The S_CODS and S_RAG shared 25–40% of the common variance. Playing positions significantly differed in BM (large effect-size differences [ES]; midfielders were lightest) and 1RM-back-squat (large ES; lowest results in midfielders). The performance levels significantly differed in age and experience in soccer; U19 achieved better results in the S_CODS (t-test: 3.61, p < 0.05, large ES) and two S_RAG protocols (t-test: 2.14 and 2.41, p < 0.05, moderate ES). Newly developed tests of soccer-specific agility are applicable to differentiate U17 and U19 players. Coaches who work with young soccer athletes should be informed that the development of soccer-specific CODS and RAG in this age is mostly dependent on training of the specific motor proficiency. PMID:29867552

The effects of concussion legislation one year later--what have we learned: a descriptive pilot survey of youth soccer player associates.

PubMed

Shenouda, Christian; Hendrickson, Peter; Davenport, Kathleen; Barber, Jason; Bell, Kathleen R

2012-06-01

To assess the knowledge of youth soccer athletes' parents, coaches, and soccer officials regarding concussion and return-to-play guidelines contained in the Lystedt Law in Washington State. Survey study. Surveys were distributed via the youth soccer association monthly electronic newsletter in September and October 2010. Links to the survey also were provided via the Washington Youth Soccer Facebook page and Twitter feed. Respondents were 18 years or older and were associated with Washington Youth Soccer. The percentage of correct responses to questions regarding the identification and management of concussion symptoms and return to play guidelines as outlined in the Lystedt Law. A total of 391 adults responded; 63% were exclusively parents, 20% were coaches, and 17% were noncoaches (eg, club officers, referees, or volunteers). A total of 96% knew that concussions were a type of traumatic brain injury, 93% identified concussions as serious, and 93% knew that loss of consciousness is not universal. From the responses, 98% identified neurological manifestations of concussions, 90% chose to delay return to play in the presence of neurological symptoms, 85% were aware of the Lystedt Law, and only 73% knew that players must receive written clearance to return to play. A total of 88% were aware that a parent or legal guardian was not allowed to clear an athlete to return to play if a trained professional was not available. Survey respondents were less sure of soccer association guidelines for reporting medical clearance to club officials. These data suggest that, although general knowledge of parents, coaches, and referees in youth soccer in Washington State is high, gaps in knowledge and practice regarding the prevention of concussion in youth soccer athletes still exist. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game

PubMed Central

Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G.; Krustrup, Peter; Mohr, Magni

2018-01-01

Abstract We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12) participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement (p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip abductors (6 ± 1%) demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery. PMID:29599862

Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game.

PubMed

Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G; Krustrup, Peter; Mohr, Magni

2018-03-01

We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12) participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement ( p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip abductors (6 ± 1%) demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery.

Effects of Sex and Event Type on Head Impact in Collegiate Soccer

PubMed Central

Reynolds, Bryson B.; Patrie, James; Henry, Erich J.; Goodkin, Howard P.; Broshek, Donna K.; Wintermark, Max; Druzgal, T. Jason

2017-01-01

Background: The effects of head impact in sports are of growing interest for clinicians, scientists, and athletes. Soccer is the most popular sport worldwide, but the burden of head impact in collegiate soccer is still unknown. Purpose: To quantify head impact associated with practicing and playing collegiate soccer using wearable accelerometers. Study Design: Descriptive epidemiological study. Methods: Mastoid patch accelerometers were used to quantify head impact in soccer, examining differences in head impact as a function of sex and event type (practice vs game). Seven female and 14 male collegiate soccer players wore mastoid patch accelerometers that measured head impacts during team events. Data were summarized for each athletic exposure, and statistical analyses evaluated the mean number of impacts, mean peak linear acceleration, mean peak rotational acceleration, and cumulative linear and rotational acceleration, each grouped by sex and event type. Results: There were no differences in the frequency or severity of head impacts between men’s and women’s soccer practices. For men’s soccer, games resulted in 285% more head impacts than practices, but there were no event-type differences in mean impact severity. Men’s soccer games resulted in more head impacts than practices across nearly all measured impact severities, which also resulted in men’s soccer games producing a greater cumulative impact burden. Conclusion: Similar to other sports, men’s soccer games have a greater impact burden when compared with practices, and this effect is driven by the quantity rather than severity of head impacts. In contrast, there were no differences in the quantity or severity of head impacts in men’s and women’s soccer practices. These data could prompt discussions of practical concern to collegiate soccer, such as understanding sex differences in head impact and whether games disproportionately contribute to an athlete’s head impact burden. PMID:28491885

The appropriateness of training exposures for match-play preparation in adolescent schoolboy and academy rugby union players.

PubMed

Phibbs, Padraic J; Jones, Ben; Read, Dale B; Roe, Gregory A B; Darrall-Jones, Joshua; Weakley, Jonathon J S; Rock, Andrew; Till, Kevin

2018-03-01

The aim of this study was to compare the physical and movement demands between training and match-play in schoolboy and academy adolescent rugby union (RU) players. Sixty-one adolescent male RU players (mean ± SD; age 17.0 ± 0.7 years) were recruited from four teams representing school and regional academy standards. Players were categorised into four groups based on playing standard and position: schoolboy forwards (n = 15), schoolboy backs (n = 15), academy forwards (n = 16) and academy backs (n = 15). Global positioning system and accelerometry measures were obtained from training and match-play to assess within-group differences between conditions. Maximum data were analysed from 79 match files across 8 matches (1.3 ± 0.5 matches per participant) and 152 training files across 15 training sessions (2.5 ± 0.5 training sessions per participant). Schoolboy forwards were underprepared for low-intensity activities experienced during match-play, with schoolboy backs underprepared for all movement demands. Academy forwards were exposed to similar physical demands in training to matches, with academy backs similar to or exceeding values for all measured variables. Schoolboy players were underprepared for many key, position-specific aspects of match-play, which could place them at greater risk of injury and hinder performance, unlike academy players who were better prepared.

Sub-maximal and maximal Yo-Yo intermittent endurance test level 2: heart rate response, reproducibility and application to elite soccer.

PubMed

Bradley, Paul S; Mohr, M; Bendiksen, M; Randers, M B; Flindt, M; Barnes, C; Hood, P; Gomez, A; Andersen, Jesper L; Di Mascio, M; Bangsbo, J; Krustrup, P

2011-06-01

The aims of this study were to (1) determine the reproducibility of sub-maximal and maximal versions of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2 test), (2) assess the relationship between the Yo-Yo IE2 test and match performance and (3) quantify the sensitivity of the Yo-Yo IE2 test to detect test-retest changes and discriminate between performance for different playing standards and positions in elite soccer. Elite (n = 148) and sub-elite male (n = 14) soccer players carried out the Yo-Yo IE2 test on several occasions over consecutive seasons. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance and heart rate after 6 min were 3.9% (n = 37) and 1.4% (n = 32), respectively. Elite male senior and youth U19 players Yo-Yo IE2 performances were better (P < 0.01) than elite youth U16s and sub-elite players (2,603 ± 451 and 2,534 ± 549 vs. 1,855 ± 535 vs. 1,749 ± 382 m). The intra- and inter-season CV for Yo-Yo IE2 test performance were 4.2 and 5.6%, respectively. A correlation was observed (P < 0.05) between Yo-Yo IE2 test performance and the total (r = 0.74) and high-intensity (r = 0.58) running distance covered in a match. A correlation was also evident (P < 0.01) between Yo-Yo IE2 test heart rate after 6 min expressed in percentage of maximal heart rate and the peak values for high-intensity running performed by midfielders in 5-min (r = -0.71), 15-min (r = -0.75) and 45-min periods (r = -0.77). The present data demonstrate that the Yo-Yo IE2 test is reproducible and can be used to determine the capacity of elite soccer players to perform intense intermittent exercise. Furthermore, the Yo-Yo IE2 test was shown to be a sensitive tool that not only relates to match performance but can also differentiate between intermittent exercise performance of players in various standards, stages of the season and playing positions.

Differences in game reading between selected and non-selected youth soccer players.

PubMed

Den Hartigh, Ruud J R; Van Der Steen, Steffie; Hakvoort, Bas; Frencken, Wouter G P; Lemmink, Koen A P M

2018-02-01

Applying an established theory of cognitive development-Skill Theory-the current study compares the game-reading skills of youth players selected for a soccer school of a professional soccer club (n = 49) and their non-selected peers (n = 38). Participants described the actions taking place in videos of soccer game plays, and their verbalisations were coded using Skill Theory. Compared to the non-selected players, the selected players generally demonstrated higher levels of complexity in their game-reading, and structured the information of game elements-primarily the player, teammate and field-at higher complexity levels. These results demonstrate how Skill Theory can be used to assess, and distinguish game-reading of youth players with different expertise, a skill important for soccer, but also for other sports.

Are Current Physical Match Performance Metrics in Elite Soccer Fit for Purpose or is the Adoption of an Integrated Approach Needed?

PubMed

Bradley, Paul S; Ade, Jack D

2018-01-18

Time-motion analysis is a valuable data-collection technique used to quantify the physical match performance of elite soccer players. For over 40 years researchers have adopted a 'traditional' approach when evaluating match demands by simply reporting the distance covered or time spent along a motion continuum of walking through to sprinting. This methodology quantifies physical metrics in isolation without integrating other factors and this ultimately leads to a one-dimensional insight into match performance. Thus, this commentary proposes a novel 'integrated' approach that focuses on a sensitive physical metric such as high-intensity running but contextualizes this in relation to key tactical activities for each position and collectively for the team. In the example presented, the 'integrated' model clearly unveils the unique high-intensity profile that exists due to distinct tactical roles, rather than one-dimensional 'blind' distances produced by 'traditional' models. Intuitively this innovative concept may aid the coaches understanding of the physical performance in relation to the tactical roles and instructions given to the players. Additionally, it will enable practitioners to more effectively translate match metrics into training and testing protocols. This innovative model may well aid advances in other team sports that incorporate similar intermittent movements with tactical purpose. Evidence of the merits and application of this new concept are needed before the scientific community accepts this model as it may well add complexity to an area that conceivably needs simplicity.

Soccer player recognition by pixel classification in a hybrid color space

NASA Astrophysics Data System (ADS)

Vandenbroucke, Nicolas; Macaire, Ludovic; Postaire, Jack-Gerard

1997-08-01

Soccer is a very popular sport all over the world, Coaches and sport commentators need accurate information about soccer games, especially about the players behavior. These information can be gathered by inspectors who watch the soccer match and report manually the actions of the players involved in the principal phases of the game. Generally, these inspectors focus their attention on the few players standing near the ball and don't report about the motion of all the other players. So it seems desirable to design a system which automatically tracks all the players in real- time. That's why we propose to automatically track each player through the successive color images of the sequences acquired by a fixed color camera. Each player which is present in the image, is modelized by an active contour model or snake. When, during the soccer match, a player is hidden by another, the snakes which track these two players merge. So, it becomes impossible to track the players, except if the snakes are interactively re-initialized. Fortunately, in most cases, the two players don't belong to the same team. That is why we present an algorithm which recognizes the teams of the players by pixels representing the soccer ground which must be withdrawn before considering the players themselves. To eliminate these pixels, the color characteristics of the ground are determined interactively. In a second step, dealing with windows containing only one player of one team, the color features which yield the best discrimination between the two teams are selected. Thanks to these color features, the pixels associated to the players of the two teams form two separated clusters into a color space. In fact, there are many color representation systems and it's interesting to evaluate the features which provide the best separation between the two classes of pixels according to the players soccer suit. Finally, the classification process for image segmentation is based on the three most

An Evidence-Based Discussion of Heading the Ball and Concussions in High School Soccer.

PubMed

Comstock, R Dawn; Currie, Dustin W; Pierpoint, Lauren A; Grubenhoff, Joseph A; Fields, Sarah K

2015-09-01

Soccer, originally introduced as a safer sport for children and adolescents, has seen a rapid increase in popularity in the United States over the past 3 decades. Recently, concerns have been raised regarding the safety of soccer ball heading (when an athlete attempts to play the ball in the air with his or her head) given the rise in concussion rates, with some calling for a ban on heading among soccer players younger than 14 years. To evaluate trends over time in boys' and girls' soccer concussions, to identify injury mechanisms commonly leading to concussions, to delineate soccer-specific activities during which most concussions occur, to detail heading-related soccer concussion mechanisms, and to compare concussion symptom patterns by injury mechanism. Retrospective analysis of longitudinal surveillance data collected from 2005-2006 through 2013-2014 in a large, nationally representative sample of US high schools. Participants were boys and girls who were high school soccer players. Concussions sustained during high school-sanctioned soccer games and practices. Mechanism and sport-specific activity of concussion. Overall, 627 concussions were sustained during 1,393,753 athlete exposures (AEs) among girls (4.50 concussions per 10,000 AEs), and 442 concussions were sustained during 1,592,238 AEs among boys (2.78 concussions per 10,000 AEs). For boys (68.8%) and girls (51.3%), contact with another player was the most common concussion mechanism. Heading was the most common soccer-specific activity, responsible for 30.6% of boys' concussions and 25.3% of girls' concussions. Contact with another player was the most common mechanism of injury in heading-related concussions among boys (78.1%) and girls (61.9%). There were few differences in concussion symptom patterns by injury mechanism. Although heading is the most common activity associated with concussions, the most frequent mechanism was athlete-athlete contact. Such information is needed to drive evidence

Understanding mental toughness in Australian soccer: perceptions of players, parents, and coaches.

PubMed

Coulter, Tristan J; Mallett, Clifford J; Gucciardi, Daniel F

2010-05-01

We explored mental toughness in soccer using a triangulation of data capture involving players (n = 6), coaches (n = 4), and parents (n = 5). Semi-structured interviews, based on a personal construct psychology (Kelly, 1955/1991) framework, were conducted to elicit participants' perspectives on the key characteristics and their contrasts, situations demanding mental toughness, and the behaviours displayed and cognitions employed by mentally tough soccer players. The results from the research provided further evidence that mental toughness is conceptually distinct from other psychological constructs such as hardiness. The findings also supported Gucciardi, Gordon, and Dimmock's (2009) process model of mental toughness. A winning mentality and desire was identified as a key attribute of mentally tough soccer players in addition to other previously reported qualities such as self-belief, physical toughness, work ethic/motivation, and resilience. Key cognitions reported by mentally tough soccer players enabled them to remain focused and competitive during training and matches and highlighted the adoption of several forms of self-talk in dealing with challenging situations. Minor revisions to Gucciardi and colleagues' definition of mental toughness are proposed.

Analysis of Cohesion and Collective Efficacy Profiles for the Performance of Soccer Players

PubMed Central

Leo, Francisco M.; Sánchez-Miguel, Pedro A.; Sánchez-Oliva, David; Amado, Diana; García-Calvo, Tomás

2013-01-01

The principal aims of the study were to define different profiles of cohesion and perceived efficacy in soccer players and to measure their differences in performance. The subjects were 235 soccer players in the under-18 category who played in the National League in Spain and 15 coaches whose ages ranged from 29 to 45 years. Diverse instruments to assess cohesion, perceived efficacy, and expectations of success were used in the study. Moreover, we measured playing time and performance. The results of the study proved the existence of four cohesion and efficacy profiles that presented significant differences in expectations of success, playing time, and performance. Furthermore, significant differences were found in the distribution of players in the teams as a function of performance. The main conclusion of this study is that soccer players with higher cohesion and collective efficacy levels belonged to teams that completed the season at the top-level classification. In contrast, athletes with low cohesion and collective efficacy usually played in unsuccessful teams. Coaches and sports psychologists are encouraged to promote both social and task cohesion and collective efficacy to enhance team performance. PMID:24511358

The efficacy of acute nutritional interventions on soccer skill performance.

PubMed

Russell, Mark; Kingsley, Michael

2014-07-01

maintain technical performance throughout match-play.

Technical match characteristics and influence of body anthropometry on playing performance in male elite team handball.

PubMed

Michalsik, Lars Bojsen; Madsen, Klavs; Aagaard, Per

2015-02-01

Modern team handball match-play imposes substantial physical and technical demands on elite players. However, only limited knowledge seems to exist about the specific working requirements in elite team handball. Thus, the purpose of this study was to examine the physical demands imposed on male elite team handball players in relation to playing position and body anthropometry. Based on continuous video recording of individual players during elite team handball match-play (62 tournament games, ∼4 players per game), computerized technical match analysis was performed in male elite team handball players along with anthropometric measurements over a 6 season time span. Technical match activities were distributed in 6 major types of playing actions (shots, breakthroughs, fast breaks, tackles, technical errors, and defense errors) and further divided into various subcategories (e.g., hard or light tackles, type of shot, claspings, screenings, and blockings). Players showed 36.9 ± 13.1 (group mean ± SD) high-intense technical playing actions per match with a mean total effective playing time of 53.85 ± 5.87 minutes. In offense, each player performed 6.0 ± 5.2 fast breaks, received 34.5 ± 21.3 tackles in total, and performed in defense 3.7 ± 3.5 blockings, 3.9 ± 3.0 claspings, and 5.8 ± 3.6 hard tackles. Wing players (84.5 ± 5.8 kg, 184.9 ± 5.7 cm) were less heavy and smaller (p < 0.001) than backcourt players (94.7 ± 7.1 kg, 191.9 ± 5.4 cm) and pivots (99.4 ± 6.2 kg, 194.8 ± 3.6 cm). In conclusion, modern male elite team handball match-play is characterized by a high number of short-term, high-intense intermittent technical playing actions. Indications of technical fatigue were observed. Physical demands differed between playing positions with wing players performing more fast breaks and less physical confrontations with opponent players than backcourt players and pivots. Body anthropometry seemed to have an important influence on playing performance

The Influence of Physical Qualities on Activity Profiles of Female Australian Football Match Play.

PubMed

Black, Georgia M; Gabbett, Tim J; Johnston, Rich D; Cole, Michael H; Naughton, Geraldine; Dawson, Brian

2018-04-01

The transition of female Australian football (AF) players from amateur to semielite competitions has the potential for athletes to be underprepared for match play. To gain an understanding of the match demands of female football, the aims of this study were to highlight the physical qualities that discriminate selected and nonselected female AF players, investigate activity profiles of female AF players, and gain an understanding of the influence of physical qualities on performance in female AF Methods: Twenty-two female AF state academy players (mean [SD]: age = 23.2 [4.5] y) and 27 nonselected players (mean [SD]: age = 23.4 [4.9] y) completed a Yo-Yo intermittent recovery test level 1, countermovement jump, and 30-m sprint tests were completed prior to the competitive season. During 14 matches, players wore global positioning system units to describe the running demands of match play. Selected players were faster over 30 m (ES = 0.57; P = .04) and covered greater distances on the Yo-Yo IR1 (ES = 1.09; P < .001). Selected midfielders spent greater time on the field and covered greater total distances (ES = 0.73-0.85; P < .01). Players faster over 5 m (r = -.612) and 30 m (r = -.807) and who performed better on the Yo-Yo IR1 (r = .489) covered greater high-speed distances during match play. An emphasis should be placed on the development of physical fitness in this playing group to ensure optimal preparation for the national competition.

Plantar pressure asymmetry and risk of stress injuries in the foot of young soccer players.

PubMed

Azevedo, Renato R; da Rocha, Emmanuel S; Franco, Pedro S; Carpes, Felipe P

2017-03-01

Asymmetries in the magnitude of plantar pressure are considered a risk factor for stress fracture of the fifth metatarsal in soccer athletes. To investigate the presence of plantar pressure asymmetries among young soccer athletes. Observational. Laboratory. Thirty young adolescents divided into a soccer player group (n = 15) or a matched control group (n = 15). Mean plantar pressure was determined for seven different regions of the foot. Data were compared between the preferred and non-preferred foot, and between the groups, during barefoot standing on a pressure mat system. Higher pressure was found in the hallux, 5th metatarsal and medial rearfoot of the non-preferred foot in the young soccer players. These asymmetries were not observed in the control group. Magnitudes of plantar pressure did not differ between the groups. Young soccer players present asymmetries in plantar pressure in the hallux, 5th metatarsal and medial rearfoot, with higher pressure observed in the non-preferred foot. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ecologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State

PubMed Central

Funnell, Mark P.; Dykes, Nick R.; Owen, Elliot J.; Mears, Stephen A.; Rollo, Ian; James, Lewis J.

2017-01-01

This study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO2max = 54.2 ± 2.9 mL∙kg−1∙min−1; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s; p = 0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km; p = 0.122) was not different between trials. There was no difference between trials for distance covered (p ≥ 0.297) or mean speed (p ≥ 0.172) for jogging or cruising. Blood glucose concentration was greater (p < 0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state. PMID:28067762

Ecologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State.

PubMed

Funnell, Mark P; Dykes, Nick R; Owen, Elliot J; Mears, Stephen A; Rollo, Ian; James, Lewis J

2017-01-05

This study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO 2max = 54.2 ± 2.9 mL∙kg -1 ∙min -1 ; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s; p = 0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km; p = 0.122) was not different between trials. There was no difference between trials for distance covered ( p ≥ 0.297) or mean speed ( p ≥ 0.172) for jogging or cruising. Blood glucose concentration was greater ( p < 0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state.

Mechanisms of injury for concussions in university football, ice hockey, and soccer.

PubMed

Delaney, J Scott; Al-Kashmiri, Ammar; Correa, José A

2014-05-01

To examine the mechanisms of injury for concussions in university football, ice hockey, and soccer. Prospective cohort design. McGill University Sport Medicine Clinic. Male and female athletes participating in varsity football, ice hockey, and soccer. Athletes were followed prospectively over a 10-year period to determine the mechanisms of injury for concussions and whether contact with certain areas of the body or individual variables predisposed to longer recovery from concussions. For soccer, data were collected on whether concussions occurred while attempting to head the ball. There were 226 concussions in 170 athletes over the study period. The side/temporal area of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. Contact from another player's head or helmet was the most probable mechanism in football and soccer. In hockey, concussion impacts were more likely to occur from contact with another body part or object rather than another head/helmet. Differences in mechanisms of injuries were found between males and females in soccer and ice hockey. Athletes with multiple concussions took longer to return to play with each subsequent concussion. Half of the concussions in soccer were related to attempting to head the soccer ball. The side of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. In ice hockey and soccer, there are differences in the mechanisms of injury for males and females within the same sport.

Extensive monitoring through multiple blood samples in professional soccer players.

PubMed

Heisterberg, Mette F; Fahrenkrug, Jan; Krustrup, Peter; Storskov, Anders; Kjær, Michael; Andersen, Jesper L

2013-05-01

The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players and to analyze different blood parameters in relation to seasonal changes in training and match exposure. Blood samples were collected 5 times during a 6-month period and analyzed for 37 variables in 27 professional soccer players from the best Danish league. Additionally, the players were tested for body composition, V[Combining Dot Above]O2max and physical performance by the Yo-Yo intermittent endurance submax test (IE2). Multiple variations in blood parameters occurred during the observation period, including a decrease in hemoglobin and an increase in hematocrit as the competitive season progressed. Iron and transferrin were stable, whereas ferritin showed a decrease at the end of the season. The immunoglobulin A (IgA) and IgM increased in the period with basal physical training and at the end of the season. Leucocytes decreased with increased physical training. Lymphocytes decreased at the end of the season. The V[Combining Dot Above]O2max decreased toward the end of the season, whereas no significant changes were observed in the IE2 test. The regular blood samples from elite soccer players reveal significant changes that may be related to changes in training pattern, match exposure, or length of the match season. Especially the end of the preparation season and at the end of the competitive season seem to be time points were the blood-derived values indicate that the players are under excessive physical strain and might be more subjected to a possible overreaching-overtraining conditions. We suggest that regular analyses of blood samples could be an important initiative to optimize training adaptation, training load, and game participation, but sampling has to be regular, and a database has to be built for each individual player.

The Running Performance Profile of Elite Gaelic Football Match-Play.

PubMed

Malone, Shane; Solan, Barry; Collins, Kieran

2017-01-01

Malone, S, Solan, B, and Collins, K. The running performance profile of elite Gaelic football match-play. J Strength Cond Res 31(1): 30-36, 2017-The current study examined (a) the match running performance of Gaelic football and (b) the decrement in match running performance with respect to position. Global positioning satellite system technologies (4-Hz; VX Sport) were used with 3 elite intercounty teams across 3 full seasons with 250 full game data sets collected. Game movements were classified according to game actions and distance covered across speed zone thresholds (total distance [TD], high-speed running distance [HSRD; ≥17 km·h], sprint distance [SD; ≥22 km·h]; accelerations [n]; peak speed [km·h]). The influence of running performance in each quarter on the subsequent quarter was analyzed across all positional roles. The mean (±SD) TD and HSRD covered during the game were 8,889 ± 1,448 m and 1,596 ± 594 m, respectively. Results show a temporal profile for TD with reductions in the second (-4.1%), third (-5.9%) and fourth (-3.8%) quarters, respectively. There was a significant reduction in HSRD in the second (-8.8%), third (-15.9%), and fourth (-19.8%) quarters when compared to the first quarter (p < 0.001). Positional differences were observed for distance-based measures with the middle 3 positions (half-back, midfield, and half-forward) completing the highest running performances. These positions also showed increased decrements in TD and HSRD and SD across quarters. The current data indicate a reduction in exercise intensity over the duration of elite Gaelic football match-play. It is unclear if this reduction is because of fatigue, pacing, contextual factors, or nutritional strategies employed by players.

An analysis of practice activities and instructional behaviours used by youth soccer coaches during practice: exploring the link between science and application.

PubMed

Ford, Paul R; Yates, Ian; Williams, A Mark

2010-03-01

We examined the practice activities and instructional behaviours employed by 25 youth soccer coaches during 70 different practice sessions. We evaluated the extent to which these activities and behaviours differ from those shown in contemporary research to best facilitate skill acquisition. Nine coaches worked with the under-9 years age group and eight coaches each with the under-13 and under-16 years age groups; nine of those coaches were employed at the elite level, nine at the sub-elite level, and seven at the non-elite level. Coaches had players spend more time in activities that were deemed less relevant to soccer match performance, termed "training form" (e.g. physical training, technique and skills practices), than activities deemed more relevant, termed "playing form" (e.g. small-sided/conditioned games and phase of play activities). Coaches provided high levels of instruction, feedback, and management, irrespective of the activity in which players engaged. Few differences in practice activities and instructional behaviours were reported across skill and age groups, implying the absence of any notable age- or skill-related progression. Findings are discussed with reference to recent research in the areas of skill acquisition, motor learning, and expert performance.

Global Mindedness as the "Goal": Soccer as a Pedagogical Tool in the Social Studies

ERIC Educational Resources Information Center

Busey, Christopher L.; Waring, Scott M.

2012-01-01

As evidenced by the Super Bowl, the Olympics, and the World Cup, sports is a major part of global society, as millions of people throughout the world tune in to view renowned sporting events each and every week. This is especially true for soccer, which is the world's most popular and global sport. Because soccer is played in nearly every country…

Caffeine-containing energy drink improves physical performance in female soccer players.

PubMed

Lara, Beatriz; Gonzalez-Millán, Cristina; Salinero, Juan Jose; Abian-Vicen, Javier; Areces, Francisco; Barbero-Alvarez, Jose Carlos; Muñoz, Víctor; Portillo, Luis Javier; Gonzalez-Rave, Jose Maria; Del Coso, Juan

2014-05-01

There is little information about the effects of caffeine intake on female team-sport performance. The aim of this study was to investigate the effectiveness of a caffeine-containing energy drink to improve physical performance in female soccer players during a simulated game. A double-blind, placebo controlled and randomized experimental design was used in this investigation. In two different sessions, 18 women soccer players ingested 3 mg of caffeine/kg in the form of an energy drink or an identical drink with no caffeine content (placebo). After 60 min, they performed a countermovement jump (CMJ) and a 7 × 30 m sprint test followed by a simulated soccer match (2 × 40 min). Individual running distance and speed were measured using GPS devices. In comparison to the placebo drink, the ingestion of the caffeinated energy drink increased the CMJ height (26.6 ± 4.0 vs 27.4 ± 3.8 cm; P < 0.05) and the average peak running speed during the sprint test (24.2 ± 1.6 vs 24.5 ± 1.7 km/h; P < 0.05). During the simulated match, the energy drink increased the total running distance (6,631 ± 1,618 vs 7,087 ± 1,501 m; P < 0.05), the number of sprints bouts (16 ± 9 vs 21 ± 13; P < 0.05) and the running distance covered at >18 km/h (161 ± 99 vs 216 ± 103 m; P < 0.05). The ingestion of the energy drink did not affect the prevalence of negative side effects after the game. An energy drink with a dose equivalent to 3 mg of caffeine/kg might be an effective ergogenic aid to improve physical performance in female soccer players.

Splenic injury after blunt abdominal trauma during a soccer (football) game.

PubMed

Padlipsky, Patricia S; Brindis, Seth; Young, Kelly D

2014-10-01

The spleen is the most commonly injured abdominal organ in children who sustain blunt abdominal trauma, and pediatric splenic injury may result from minor mechanisms of injury, including sports participation. We present 2 cases of splenic injury in soccer goalies because of blunt abdominal trauma sustained during game play. Although abdominal organ injuries are uncommon in soccer, emergency medicine and primary care physicians must be aware of the possibility. A high index of suspicion and careful physical examination are key in making the diagnosis.

Coping with heat stress during match-play tennis: Does an individualised hydration regimen enhance performance and recovery?

PubMed Central

Périard, Julien D; Racinais, Sebastien; Knez, Wade L; Herrera, Christopher P; Christian, Ryan J; Girard, Olivier

2014-01-01

Objectives To determine whether an individualised hydration regimen reduces thermal, physiological and perceptual strain during match-play tennis in the heat, and minimises alterations in neuromuscular function and physical performance postmatch and into recovery. Methods 10 men undertook two matches for an effective playing time (ball in play) of 20 min (∼113 min) in ∼37°C and ∼33% RH conditions. Participants consumed fluids ad libitum during the first match (HOT) and followed a hydration regimen (HYD) in the second match based on undertaking play euhydrated, standardising sodium intake and minimising body mass losses. Results HYD improved prematch urine specific gravity (1.013±0.006 vs 1.021±0.009 g/mL; p<0.05). Body mass losses (∼0.3%), fluid intake (∼2 L/h) and sweat rates (∼1.6 L/h) were similar between conditions. Core temperature was higher during the first 10 min of effective play in HOT (p<0.05), but increased similarly (∼39.3°C) on match completion. Heart rate was higher (∼11 bpm) throughout HOT (p<0.001). Thermal sensation was higher during the first 7.5 min of effective play in HOT (p<0.05). Postmatch knee extensor and plantar flexor strength losses, along with reductions in 15 m sprint time and repeated-sprint ability (p<0.05), were similar in both conditions, and were restored within 24 h. Conclusions Both the hydration regimen and ad libitum fluid consumption allowed for minimal body mass losses (<1%). However, undertaking match-play in a euhydrated state attenuated thermal, physiological and perceptual strain. Maximal voluntary strength in the lower limbs and repeated-sprint ability deteriorated similarly in both conditions, but were restored within 24 h. PMID:24668383

Coping with heat stress during match-play tennis: does an individualised hydration regimen enhance performance and recovery?

PubMed

Périard, Julien D; Racinais, Sebastien; Knez, Wade L; Herrera, Christopher P; Christian, Ryan J; Girard, Olivier

2014-04-01

To determine whether an individualised hydration regimen reduces thermal, physiological and perceptual strain during match-play tennis in the heat, and minimises alterations in neuromuscular function and physical performance postmatch and into recovery. 10 men undertook two matches for an effective playing time (ball in play) of 20 min (∼113 min) in ∼37°C and ∼33% RH conditions. Participants consumed fluids ad libitum during the first match (HOT) and followed a hydration regimen (HYD) in the second match based on undertaking play euhydrated, standardising sodium intake and minimising body mass losses. HYD improved prematch urine specific gravity (1.013±0.006 vs 1.021±0.009 g/mL; p<0.05). Body mass losses (∼0.3%), fluid intake (∼2 L/h) and sweat rates (∼1.6 L/h) were similar between conditions. Core temperature was higher during the first 10 min of effective play in HOT (p<0.05), but increased similarly (∼39.3°C) on match completion. Heart rate was higher (∼11 bpm) throughout HOT (p<0.001). Thermal sensation was higher during the first 7.5 min of effective play in HOT (p<0.05). Postmatch knee extensor and plantar flexor strength losses, along with reductions in 15 m sprint time and repeated-sprint ability (p<0.05), were similar in both conditions, and were restored within 24 h. Both the hydration regimen and ad libitum fluid consumption allowed for minimal body mass losses (<1%). However, undertaking match-play in a euhydrated state attenuated thermal, physiological and perceptual strain. Maximal voluntary strength in the lower limbs and repeated-sprint ability deteriorated similarly in both conditions, but were restored within 24 h.

Match-Play Running Performance and Exercise Intensity in Elite International Women's Rugby Sevens.

PubMed

Malone, Shane; Earls, Marian; Shovlin, Aidan; Eddy, Anthony; Winkelman, Nick

2018-06-14

Malone, S, Earls, M, Shovlin, A, Eddy, A, and Winkleman, N. Match-play running performance and exercise intensity in elite international women's rugby sevens. J Strength Cond Res XX(X): 000-000, 2018-The aim of the current investigation was to describe the running and physiological performance demands of elite women's rugby sevens match-play. Twenty-seven (n = 27) rugby seven's players (24.4 ± 2.1 years; 168 ± 7.1 cm; 67.9 ± 4.3 kg) were recruited for the current investigation. Across the observational period, 36 games were analyzed; during these games, players wore global positioning system technology (10-Hz, Statsports Viper Pod; STATSports, Newry, Northern Ireland, United Kingdom) and heart rate monitors (Polar Team System, Polar Electro Oy, Kempele, Finland). A total of 250 individual player data sets were obtained for final analysis. Players were categorized based on positional groups; backs and forwards, and monitored across halves of play. The mean distance covered during match-play was 1,625 ± 132 m which equates to a relative running performance of 116.8 ± 9.4 m·min. The high-speed distance of players was 199 ± 44 m, which equates to a relative high-speed running performance of 14.2 ± 3.1 m·min. Significant reductions in high-speed running (p = 0.003; effect size [ES]: 0.23; 90% confidence interval [CI]: 0.11-0.41) and significant increases in lower speed running were observed across halves of play (p = 0.04; ES: 0.33; 90% CI: 0.16-0.54). Across the duration of match-play, players spent over 75% of the time above 80% of heart rate maximum (HRmax). Backs were found to have a higher reduction in total distance (p = 0.345; ES: 0.21; 90% CI: 0.11-0.31), high-speed distance (p = 0.04; ES: 0.61; 90% CI: 0.48-0.77), sprint distance (p = 0.034; ES: 0.11; 90% CI: 0.02-0.21), and average sprint distance (p = 0.03; ES: 0.33; 90% CI: 0.08-0.44) across halves of play when compared to forwards. Normative data are now provided to coaches who need to consider the

Minimizing Head Acceleration in Soccer: A Review of the Literature.

PubMed

Caccese, Jaclyn B; Kaminski, Thomas W

2016-11-01

Physicians and healthcare professionals are often asked for recommendations on how to keep athletes safe during contact sports such as soccer. With an increase in concussion awareness and concern about repetitive subconcussion, many parents and athletes are interested in mitigating head acceleration in soccer, so we conducted a literature review on factors that affect head acceleration in soccer. We searched electronic databases and reference lists to find studies using the keywords 'soccer' OR 'football' AND 'head acceleration'. Because of a lack of current research in soccer heading biomechanics, this review was limited to 18 original research studies. Low head-neck segment mass predisposes athletes to high head acceleration, but head-neck-torso alignment during heading and follow-through after contact can be used to decrease head acceleration. Additionally, improvements in symmetric neck flexor and extensor strength and neuromuscular neck stiffness can decrease head acceleration. Head-to-head impacts and unanticipated ball contacts result in the highest head acceleration. Ball contacts at high velocity may also be dangerous. The risk of concussive impacts may be lessened through the use of headgear, but headgear may also cause athletes to play more recklessly because they feel a sense of increased security. Young, but physically capable, athletes should be taught proper heading technique in a controlled setting, using a carefully planned progression of the skill.

Physical Demands of Representative Match-Play in Adolescent Rugby Union.

PubMed

Read, Dale B; Jones, Ben; Phibbs, Padraic J; Roe, Gregory A B; Darrall-Jones, Joshua D; Weakley, Jonathon J S; Till, Kevin

2017-05-01

Read, DB, Jones, B, Phibbs, PJ, Roe, GAB, Darrall-Jones, J, Weakley, JJS, and Till, K. Physical demands of representative match-play in adolescent rugby union. J Strength Cond Res 31(5): 1290-1296, 2017-The purpose of this study was to quantify the physical demands of representative adolescent rugby union match-play and investigate the difference between playing positions and age groups. Players (n = 112) were classified into 6 groups by playing position (forwards and backs) and age group (U16, U18, and U20). The physical demands were measured using microsensor-based technology and analyzed using magnitude-based inferences to assess practical importance. Backs had a greater relative distance (except U16s) and a greater high-speed running distance per minute than forwards, with the magnitude of difference between the positions becoming larger in older age groups. Forwards had higher values of PlayerLoad (PL) per minute (accumulated accelerations from the 3 axes of movement) and PL slow per minute (accumulated accelerations from the 3 axes of movement where velocity is <2 m·s) than backs at all age groups. Relative distance, low-, and high-speed running per minute all had a trend to be lower in older age groups for both positions. PlayerLoad per minute was greater in U18 than that in U16 and U20 for both positions. PlayerLoad slow per minute was greater for older age groups besides the U18 and U20 comparisons, which were unclear. The contrasts in physical demands experienced by different positions reinforce the need for greater exposure to sprinting and collision-based activity for backs and forwards, respectively. Given PL metrics peak at U18 and locomotor demands seem to be lower in older ages, the demands of representative adolescent rugby union do not seem to be greater at U20 as expected.

Effects of Plyometric and Sprint Training on Physical and Technical Skill Performance in Adolescent Soccer Players.

PubMed

Sáez de Villarreal, Eduardo; Suarez-Arrones, Luis; Requena, Bernardo; Haff, Gregory G; Ferrete, Carlos

2015-07-01

To determine the influence of a short-term combined plyometric and sprint training (9 weeks) within regular soccer practice on explosive and technical actions of pubertal soccer players during the in-season. Twenty-six players were randomly assigned to 2 groups: control group (CG) (soccer training only) and combined group (CombG) (plyometric + acceleration + dribbling + shooting). All players trained soccer 4 times per week and the experimental groups supplemented the soccer training with a proposed plyometric-sprint training program for 40 minutes (2 days per weeks). Ten-meter sprint, 10-m agility with and without ball, CMJ and Abalakov vertical jump, ball-shooting speed, and Yo-Yo intermittent endurance test were measured before and after training. The experimental group followed a 9-week plyometric and sprint program (i.e., jumping, hurdling, bouncing, skipping, and footwork) implemented before the soccer training. Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the CG; however, meaningful improvement was found in all variables in the experimental group: CMJ (effect size [ES] = 0.9), Abalakov vertical jump (ES = 1.3), 10-m sprint (ES = 0.7-0.9), 10-m agility (ES = 0.8-1.2), and ball-shooting speed (ES = 0.7-0.8). A specific combined plyometric and sprint training within regular soccer practice improved explosive actions compared with conventional soccer training only. Therefore, the short-term combined program had a beneficial impact on explosive actions, such as sprinting, change of direction, jumping, and ball-shooting speed which are important determinants of match-winning actions in soccer performance. Therefore, we propose modifications to current training methodology for pubertal soccer players to include combined plyometric and speed training for athlete preparation in this sport.

Increase in upper extremity fractures in young male soccer players in the Netherlands, 1998-2009.

PubMed

de Putter, C E; van Beeck, E F; Burdorf, A; Borsboom, G J J M; Toet, H; Hovius, S E R; Selles, R W

2015-08-01

Young male soccer players have been identified as a target group for injury prevention, but studies addressing trends and determinants of injuries within this group are scarce. The goal of this study was to analyze age-specific trends in hospital-treated upper extremity fractures (UEF) among boys playing soccer in the Netherlands and to explore associated soccer-related factors. Data were obtained from a national database for the period 1998-2009. Rates were expressed as the annual number of UEF per 1000 soccer players. Poisson's regression was used to explore the association of UEF with the number of artificial turf fields and the number of injuries by physical contact. UEF rates increased significantly by 19.4% in boys 5-10 years, 73.2% in boys 11-14 years, and 38.8% in boys 15-18 years old. The number of injuries by physical contact showed a significant univariate association with UEF in boys 15-18 years old. The number of artificial turf fields showed a significant univariate association with UEF in all age groups, and remained significant for boys aged 15-18 years in a multivariate model. This study showed an increase of UEF rates in boys playing soccer, and an independent association between artificial turf fields and UEF in the oldest boys. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Injury incidence in a Premier League youth soccer academy using the consensus statement: a prospective cohort study

PubMed Central

Renshaw, Andrew

2016-01-01

Background There is an established risk of injury to young athletes exposed to high training loads. Identifying and monitoring injury risk is essential to aid prevention. The aim of this study was to use the consensus statement to determine the incidence and pattern of injury in 1 English Premier League soccer academy during 1 season. Methods A prospective cohort study included 181 elite academy soccer players during the 2012–2013 season. Players were divided into 5 age groups between 9 and 18 years. The number, type and incidence of injuries were recorded during matches and training. Incidence was calculated per 1000 hours of exposure. Results 127 injuries occurred during 29 346 hours of soccer exposure. 72% of injuries were non-contact related. Under (U)18 players sustained the highest number of match injuries. U12–14 players sustained the highest number of training injuries and injuries overall. U16 players sustained the highest number of severe injuries, and U18 players sustained the highest number of moderate injuries. U18 players sustained the highest number of injuries/1000 hours of training and overall. U15 players sustained the highest number of injuries/1000 hours of matches, the highest number of recurrent injuries and the highest incidence of recurrence. The most common injuries were muscle injuries in U15 and U18 players. The most common injury location was the anterior thigh, with the majority of these occurring in training. Conclusions Using the consensus statement, this study used a repeatable method to identify the injury profile of elite academy-level soccer players. PMID:27900186

NUTRITIONAL INTAKE AND NUTRITIONAL STATUS IN ELITE MEXICAN TEENAGERS SOCCER PLAYERS OF DIFFERENT AGES.

PubMed

Hidalgo y Teran Elizondo, Roberto; Martín Bermudo, Francisco Manuel; Peñaloza Mendez, Ricardo; Berná Amorós, Genoveva; Lara Padilla, Eleazar; Berral de la Rosa, Francisco José

2015-10-01

nutritional intake and status of soccer players has attracted not much research attention. Many soccer players follow an inadequate nutritional intake and have a poor nutritional status. This is relevant in youngsters soccer players, in order to improve performance and promote healthy dietary practices. analyze anthropometric characterizes, evaluate nutritional intake and status, dietary habits and pre- and post-exercise meals in elite teenagers soccer players. seventy-two young male soccer players (15-20 years) from four junior teams of a soccer Club from the Mexican National Soccer League were measured for height, seat height, weight, 6 skinfolds, 6 diameters and 7 circumferences, height-for-age and BMI-for-age values. Skin, adipose, muscle, bone and residual tissue masses were calculated with the Ross and Kerr equation. Resting energy expenditure and intake was also measured. Daily dietary intake was self-recorded for 4 consecutive days (excluding the match day) using a digital food-weighing scale and a food record questionnaire. Dietary analysis was performed using the NutriBase 7 Clinical software. Several biochemical values were determined. One-way analysis of variance (ANOVA) and post hoc testing was performed using t-tests with a Bonferroni correction. all soccer players were within the normal range values for anthropometric parameters studies, when compared with other adolescent elite soccer teams. Values of plasma glucose, urea, creatinine, uric acid, lipid profile and total proteins were within normal range for young adult population, although albumin levels were high. Moreover, 14% and 20% of soccer players presented hyperuricemia and elevated total cholesterol levels respectively. Energy expenditure and intake were within normal range for all teenager elite soccer players. However, two teams shower significant lower intakes than demands. All macronutrient intakes were within recommendations, except protein that was higher. Micronutrient intake exceeded

Physique and Body Composition in Soccer Players across Adolescence

PubMed Central

Nikolaidis, Pantelis Theodoros; Vassilios Karydis, Nikos

2011-01-01

Purpose Although the contribution of physique and body composition in soccer performance was recognized, these parameters of physical fitness were not well-studied in adolescent players. Aim of this study was to investigate physique and body composition across adolescence. Methods Male adolescents (N=297 aged 12.01–20.98 y), classified into nine one-year age-groups, child (control group, N=16 aged 7.34–11.97 y) and adult players (control group, N=29 aged 21.01–31.59 y), all members of competitive soccer clubs, performed a series of anthropometric measures (body mass, height, skinfolds, circumferences and girths), from which body mass index (BMI), percentage of body fat (BF%), fat mass (FM), fat free mass (FFM) and somatotype (Heath-Carter method) were calculated. Results Age had a positive association with FM (r=0.2, P<0.001) and FFM (r=0.68, P<0.001), and a negative association with BF (r=−0.12, P=0.047). Somatotype components changed across adolescence as well; age was linked to endomorphy (r=−0.17, P=0.005), mesomorphy (r=0.14, P=0.019) and ectomorphy (r=−0.17, P=0.004). Compared with age-matched general population, participants exhibited equal body mass, higher stature, lower body mass index and lower BF. Conclusion During adolescence, soccer players presented significant differences in terms of body composition and physique. Thus, these findings could be employed by coaches and fitness trainers engaged in soccer training in the context of physical fitness assessment and talent identification. PMID:22375222

On referee bias, crowd size, and home advantage in the English soccer Premiership.

PubMed

Johnston, Ron

2008-04-01

In a recent paper in this journal, Boyko and colleagues (2007) identified differences in attendance and referee bias as factors influencing home advantage at soccer matches in the English Premiership. A replication of their study using more recent data found no evidence to sustain either of their claims.

Heading and head injuries in soccer.

PubMed

Kirkendall, D T; Jordan, S E; Garrett, W E

2001-01-01

In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

Consequences of players' dismissal in professional soccer: a crisis-related analysis of group-size effects.

PubMed

Bar-Eli, Michael; Tenenbaum, Gershon; Geister, Sabine

2006-10-01

This study documents the effect of players' dismissals on team performance in professional soccer. Our aim was to determine whether the punishment meted out for unacceptable player behaviour results in reduced team performance. The official web site of the German Soccer Association was used for coding data from games played in the first Bundesliga between the 1963 - 64 and 2003 - 04 (n = 41) seasons. A sample of 743 games where at least one red card was issued was used to test hypotheses derived from crisis theory (Bar-Eli & Tenenbaum, 1989a). Players' dismissals weaken a sanctioned team in terms of the goals and final score following the punishment. The chances of a sanctioned team scoring or winning were substantially reduced following the sanction. Most cards were issued in the later stages of matches. The statistics pertaining to outcome results as a function of game standing, game location, and time phases - all strongly support the view that teams can be considered conceptually similar to individuals regarding the link between stress and performance. To further develop the concept of team and individual psychological performance crisis in competition, it is recommended that reversal theory (Apter, 1982) and self-monitoring and distraction theories (Baumeister, 1984) be included in the design of future investigations pertaining to choking under pressure.

Perfectionism and sport-specific engagement in elite youth soccer players.

PubMed

Larkin, Paul; O'Connor, Donna; Williams, A Mark

2016-07-01

It is acknowledged that the time invested in sport-specific activities contributes to higher levels of performance. However, there is limited understanding of the potential impact of personality traits, such as perfectionism, on engagement in sport-specific activities. In the current study, we examine whether elite youth soccer players who demonstrate higher and lower levels of perfectionistic strivings tendencies can be differentiated based on their sport-specific engagement. The Sport Multidimensional Perfectionism Scale 2 and an adapted Player History Questionnaire were completed by 419 elite youth male soccer players competing at the Australian age-related national youth championships (under 13, n = 133; under 14, n = 166; under 15, n = 120). A quartile split approach was used to separate higher (n = 100) and lower (n = 107) perfectionistic strivings groups. Findings revealed the higher perfectionistic strivings group accumulated more time in sport-specific activities, including coach-led practice, individual practice, peer-led play and indirect involvement in soccer when compared to individuals with lower perfectionistic strivings tendencies. Descriptive analysis indicates this equates to approximately 159 h a year (i.e. 17 h coach-led practice, 22 h individual practice, 60 h of peer-led play and 60 h of indirect involvement) more than the lower perfectionistic strivings group. In summary, the results suggest players with varying levels of perfectionistic strivings may be differentiated based on their engagement in soccer-specific activity in a sample of elite youth players in Australia, and suggests that perfectionistic strivings may have an adaptive influence on sport-specific engagement.

Torque-angle-velocity Relationships and Muscle Performance of Professional and Youth Soccer Players.

PubMed

Mazuquin, B F; Dela Bela, L F; Pelegrinelli, A R M; Dias, J M; Carregaro, R L; Moura, F A; Selfe, J; Richards, J; Brown, L E; Cardoso, J R

2016-11-01

Soccer matches consist of a variety of different activities, including repeated sprints. Time to attain velocity (TTAV), load range (LR) and the torque-angle-velocity relationship (TAV 3D ) represent an important measurement of muscle performance, however there are few related studies. The aim of this study was to compare these outcomes between soccer players of different age category. 17 professional (PRO) and 17 under-17 (U17) soccer players were assessed for concentric knee flexion/extension at 60, 120 and 300°/s. For the extensor muscles, differences were found in favor of the U17 group for TTAV and LR outcomes at 120°/s, however, the PRO group maintained higher torques in both movement directions in comparison to the U17 in TAV 3D evaluation. These results suggest that muscle performance of the PRO group is more efficient than the U17 group. © Georg Thieme Verlag KG Stuttgart · New York.

Assessing the Effectiveness of the Functional Movement Screen in Predicting Noncontact Injury Rates in Soccer Players.

PubMed

Smith, Paul D; Hanlon, Michael P

2017-12-01

Smith, PD, and Hanlon, D. Assessing the effectiveness of the functional movement screen in predicting noncontact injury rates in soccer players. J Strength Cond Res 31(12): 3327-3332, 2017-This study assessed if the Functional Movement Screen (FMS) can accurately predict noncontact injury in adult soccer players when normalizing noncontact injury occurrence against match exposure levels. Senior male players (n = 89) from 5 League of Ireland semiprofessional clubs participated in the study (mean age = 23.2 ± 4.4 years; mean height = 179.5 ± 6.6 cm; mean body mass = 77.5 ± 7.8 kg). Participants performed the FMS during preseason, and their injury occurrence rates and match minutes were tracked throughout 1 season. In total, 66 noncontact injuries were recorded. No significant difference was found in FMS composite scores between players receiving noncontact injuries and players not suffering a noncontact injury (p = 0.96). There was no significant difference in exposure-normalized noncontact injury incidence between those scoring 14 or below and those scoring above 14 on the FMS (0.36 vs. 0.29 non-contact injuries per player per 1,000 match minutes). Players scoring 14 or below on the FMS had an odds ratio of 0.63 (p = 0.45; 95% CI = 0.19-2.07) of receiving a noncontact injury. Despite previous research showing links between low FMS composite scores and subsequent injury, these results suggest that the FMS cannot accurately predict a male soccer player's likelihood of receiving a noncontact injury and that a lower FMS composite score does not significantly increase their noncontact injury incidence rate per 1,000 match minutes. Caution should therefore be used when using the FMS as a predictor of noncontact injury, and pain prevalence during the FMS, previous injuries, and training/match exposure levels should also be taken into account.

ISOKINETIC KNEE MUSCLE STRENGTH PROFILE IN BRAZILIAN MALE SOCCER, FUTSAL, AND BEACH SOCCER PLAYERS: A CROSS-SECTIONAL STUDY

PubMed Central

Mascarin, Naryana C.; Vargas, Valentine Z.; Vancini, Rodrigo L.; Andrade, Marília S.

2017-01-01

Background Anterior cruciate ligament injury is higher in soccer athletes as compared to athletes of other sports. Risk factors for anterior cruciate ligament injury include low knee hamstring/quadriceps strength ratio and bilateral strength deficits. Purpose To investigate isokinetic thigh muscles strength, hamstring/quadriceps strength ratio, and bilateral strength comparisons in athletes who participate in professional soccer, futsal, and beach soccer. Study Design Cross-sectional study. Methods Brazilian professional soccer (n=70), futsal (n=30), and beach soccer (n=12) players were isokinetically assessed to examine strength of knee extensors and flexors at 60 degrees/second in concentric mode, to measure peak torque of dominant and non-dominant limbs. Results In the dominant limb, for extensors muscles, futsal players presented significantly lower peak torque values (223.9 ± 33.4 Nm) than soccer (250.9 ± 43.0 Nm; p=0.02) and beach soccer players (253.1 ± 32.4 Nm; p=0.03). Peak torque for extensor muscles in the non-dominant limb was significantly lower in futsal (224.0 ± 35.8 Nm) than in beach soccer players (256.8 ± 39.8 Nm; p=0.03). Hamstring/quadriceps strength ratio for dominant limbs for futsal (57.6 ± 10.1%), soccer (53.5 ± 8.8%), and beach soccer (56.3 ± 8.4%) players presented no significant differences between groups; however, the mean values were lower than recommended values found in the literature. There were no strength deficits for any of the evaluated groups when compared bilaterally. Conclusions Futsal athletes presented lower values for quadriceps strength than soccer and beach soccer athletes. Futsal, soccer, and beach soccer players presented no strength asymmetries, but they presented with strength imbalance in hamstring/quadriceps strength ratio. Level of Evidence 3 PMID:29234562

Effects of the performance level and the FIFA "11" injury prevention program on the injury rate in Italian male amateur soccer players.

PubMed

Gatterer, H; Ruedl, G; Faulhaber, M; Regele, M; Burtscher, M

2012-02-01

Soccer is characterized by high injury rates that necessitate interventions for its reduction. The "11" is a multi-modal preventive program that was developed to reduce injury rate. However, outcomes on the effectiveness of the program are not unambiguous and data for the largest group at risk (i.e., male adult amateur players) are missing. The study aims to assess the injury rate in male adult amateur soccer players of different levels and to evaluate the effectiveness of the prevention program the "11". Three amateur soccer teams participated in the study during the first round of a competition season. Two teams played at a regional level (6th Italian league) and one team at a provincial level (7th Italian league). The regional league is of a higher skill level compared to the provincial league. Duration and frequency of training and match sessions and the occurrence of time-loss injuries were recorded. One team of the 6th league performed an injury prevention program. The total injury rate for the intervention and the control team in the 6th league was 3.3 (CI 0.7-5.9) and 4.3 (CI 1.3-7.3) injuries/1000 h, respectively (P=0.841). The 6th league control team tended to have a lesser injury rate compared to the 7th league team (P=0.081). The relative risk was 2 fold higher in the 7th compared to the 6th league team (P=0.0285 one tailed). Present results show that injury rate in amateur soccer depended rather on the skill level than the prevention program. In this study the prevention program the "11" was not shown to be highly effective in soccer player of intermediate level (i.e., 6th Italian league).

Mental Fatigue: Impairment of Technical Performance in Small-Sided Soccer Games.

PubMed

Badin, Oliver O; Smith, Mitchell R; Conte, Daniele; Coutts, Aaron J

2016-11-01

To assess the effects of mental fatigue on physical and technical performance in small-sided soccer games. Twenty soccer players (age 17.8 ± 1.0 y, height 179 ± 5 cm, body mass 72.4 ± 6.8 kg, playing experience 8.3 ± 1.4 y) from an Australian National Premier League soccer club volunteered to participate in this randomized crossover investigation. Participants played 15-min 5-vs-5 small-sided games (SSGs) without goalkeepers on 2 occasions separated by 1 wk. Before the SSG, 1 team watched a 30-min emotionally neutral documentary (control), while the other performed 30 min of a computer-based Stroop task (mental fatigue). Subjective ratings of mental and physical fatigue were recorded before and after treatment and after the SSG. Motivation was assessed before treatment and SSG; mental effort was assessed after treatment and SSG. Player activity profiles and heart rate (HR) were measured throughout the SSG, whereas ratings of perceived exertion (RPEs) were recorded before the SSG and immediately after each half. Video recordings of the SSG allowed for notational analysis of technical variables. Subjective ratings of mental fatigue and effort were higher after the Stroop task, whereas motivation for the upcoming SSG was similar between conditions. HR during the SSG was possibly higher in the control condition, whereas RPE was likely higher in the mental-fatigue condition. Mental fatigue had an unclear effect on most physical-performance variables but impaired most technical-performance variables. Mental fatigue impairs technical but not physical performance in small-sided soccer games.

Aggressor and victim perspective-related differences in perceived legitimacy of aggression in soccer.

PubMed

Traclet, Alan; Rascle, Olivier; Souchon, Nicolas; Coulomb-Cabagno, Genevieve; Dosseville, Fabrice

2008-02-01

The purpose of this role-playing study was to explore the perceived legitimacy of aggression in soccer as a function of perspective-related differences (aggressor vs victim) and type of aggression (instrumental vs hostile). 120 soccer players watched videotaped aggressive interactions in soccer and took the perspective of the actors (aggressor then victim or the reverse). Then they rated the legitimacy of each aggressive behavior depending on its ultimate goal (instrumental then hostile or the reverse). When participants adopted the aggressor perspective, they perceived instrumental aggression as more legitimate than hostile aggression. In contrast, when participants took the perspective of the victim, no significant difference was found regardless of the type of aggression. The discussion focussed on implications and consequences of such divergences in aggressive sport situations.

The Mental Skills Training of University Soccer Players

ERIC Educational Resources Information Center

Sadeghi, Hassan; Omar-Fauzee, Mohd-Sofian; Jamalis, Marjohan; Ab-Latif, Rozita; Cheric, Majid Chahrdah

2010-01-01

The purpose of this study is to identify the kind of mental skills training needed most by the university soccer players. Eight male university football players (aged 25 to 36) from one large university in Kuala Lumpur agreed to participate in this study. On average, they have 10 years of playing experience. All of them have signed the informed…

Evidence for Acute Electrophysiological and Cognitive Changes Following Routine Soccer Heading.

PubMed

Di Virgilio, Thomas G; Hunter, Angus; Wilson, Lindsay; Stewart, William; Goodall, Stuart; Howatson, Glyn; Donaldson, David I; Ietswaart, Magdalena

2016-11-01

There is growing concern around the effects of concussion and sub-concussive impacts in sport. Routine game-play in soccer involves intentional and repeated head impacts through ball heading. Although heading is frequently cited as a risk to brain health, little data exist regarding the consequences of this activity. This study aims to assess the immediate outcomes of routine football heading using direct and sensitive measures of brain function. Nineteen amateur football players (5 females; age 22±3y) headed machine-projected soccer balls at standardized speeds, modelling routine soccer practice. The primary outcome measure of corticomotor inhibition measured using transcranial magnetic stimulation, was assessed prior to heading and repeated immediately, 24h, 48h and 2weeks post-heading. Secondary outcome measures were cortical excitability, postural control, and cognitive function. Immediately following heading an increase in corticomotor inhibition was detected; further to these electrophysiological alterations, measurable reduction memory function were also found. These acute changes appear transient, with values normalizing 24h post-heading. Sub-concussive head impacts routine in soccer heading are associated with immediate, measurable electrophysiological and cognitive impairments. Although these changes in brain function were transient, these effects may signal direct consequences of routine soccer heading on (long-term) brain health which requires further study. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Caffeine supplementation does not affect match activities and fatigue resistance during match play in young football players.

PubMed

Pettersen, Svein Arne; Krustrup, Peter; Bendiksen, Mads; Randers, Morten Bredsgaard; Brito, Joao; Bangsbo, Jens; Jin, Yun; Mohr, Magni

2014-12-01

Abstract The study examined the effect of caffeine supplementation on match activities and development of fatigue during a football match. In a randomised, double-blind cross-over design, two experimental football games separated by 7 days were organised between the junior teams of two professional football clubs (17.6 ± 1.1 years (±s), 71.7 ± 6.9 kg, 13.9% ± 5.0% body fat). The players ingested either a capsule of 6 mg · kg -1  b.w. caffeine or placebo (dextrose) 65 min prior to the matches. Match activities were assessed using the ZXY match analysis system, and a Yo-Yo intermittent recovery test-level 2 (Yo-Yo IR2) was conducted immediately post-game. Heart rate was monitored throughout the game, and blood samples were obtained at baseline, half-time and after the game. There were no differences between caffeine and placebo regarding total distance covered (10,062 ± 916 vs 9854 ± 901 m), high-intensity running (557 ± 178 vs 642 ± 240 m), sprinting distance (109 ± 58 vs 112 ± 69 m) or acceleration counts (123 ± 31 vs 126 ± 24). In both trials, players displayed lower (P < 0.05) values in total distance and acceleration counts in the last 15 min compared to all other 15-min periods of the matches. Post-game Yo-Yo IR2 performance was not different between game trials (caffeine: 829 ± 322 m; placebo 819 ± 289 m). In conclusion, oral caffeine administration does not appear to have an ergogenic effect in young football players during match play.

Creating drag and lift curves from soccer trajectories

NASA Astrophysics Data System (ADS)

Goff, John Eric; Kelley, John; Hobson, Chad M.; Seo, Kazuya; Asai, Takeshi; Choppin, S. B.

2017-07-01

Trajectory analysis is an alternative to using wind tunnels to measure a soccer ball’s aerodynamic properties. It has advantages over wind tunnel testing such as being more representative of game play. However, previous work has not presented a method that produces complete, speed-dependent drag and lift coefficients. Four high-speed cameras in stereo-calibrated pairs were used to measure the spatial co-ordinates for 29 separate soccer trajectories. Those trajectories span a range of launch speeds from 9.3 to 29.9 m s-1. That range encompasses low-speed laminar flow of air over a soccer ball, through the drag crises where air flow is both laminar and turbulent, and up to high-speed turbulent air flow. Results from trajectory analysis were combined to give speed-dependent drag and lift coefficient curves for the entire range of speeds found in the 29 trajectories. The average root mean square error between the measured and modelled trajectory was 0.028 m horizontally and 0.034 m vertically. The drag and lift crises can be observed in the plots of drag and lift coefficients respectively.

Home advantage in soccer--A matter of expectations, goal setting and tactical decisions of coaches?

PubMed

Staufenbiel, Kathrin; Lobinger, Babett; Strauss, Bernd

2015-01-01

In soccer, home teams win about 67% of decided games. The causes for this home advantage are still unresolved. There is a shortage of research on the psychological states of actors involved. In this study, we examined soccer coaches' expectations, goal setting and tactical decisions in relation to game location. Soccer coaches (N = 297) with different expertise levels participated in an experimental, online management game and were randomly assigned to one of two groups, "home game (HG)" or "away game." Participants received information on the game for which they were asked to make decisions in multiple points. The only differing information between groups was game location. Regardless of expertise, HG coaches had higher expectations to win, set more challenging goals and decided for more offensive and courageous playing tactics. Possible consequences of these findings concerning home advantage in soccer are discussed.

Deviating running kinematics and hamstring injury susceptibility in male soccer players: Cause or consequence?

PubMed

Schuermans, Joke; Van Tiggelen, Damien; Palmans, Tanneke; Danneels, Lieven; Witvrouw, Erik

2017-09-01

Although the vast majority of hamstring injuries in male soccer are sustained during high speed running, the association between sprinting kinematics and hamstring injury vulnerability has never been investigated prospectively in a cohort at risk. This study aimed to objectify the importance of lower limb and trunk kinematics during full sprint in hamstring injury susceptibility. Cohort study; level of evidence, 2. At the end of the 2013 soccer season, three-dimensional kinematic data of the lower limb and trunk were collected during sprinting in a cohort consisting of 30 soccer players with a recent history of hamstring injury and 30 matched controls. Subsequently, a 1.5 season follow up was conducted for (re)injury registry. Ultimately, joint and segment motion patterns were submitted to retro- and prospective statistical curve analyses for injury risk prediction. Statistical analysis revealed that index injury occurrence was associated with higher levels of anterior pelvic tilting and thoracic side bending throughout the airborne (swing) phases of sprinting, whereas no kinematic differences during running were found when comparing players with a recent hamstring injury history with their matched controls. Deficient core stability, enabling excessive pelvis and trunk motion during swing, probably increases the primary injury risk. Although sprinting encompasses a relative risk of hamstring muscle failure in every athlete, running coordination demonstrated to be essential in hamstring injury prevention. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of the postural control strategies used to play two Wii Fit™ videogames.

PubMed

Michalski, A; Glazebrook, C M; Martin, A J; Wong, W W N; Kim, A J W; Moody, K D; Salbach, N M; Steinnagel, B; Andrysek, J; Torres-Moreno, R; Zabjek, K F

2012-07-01

The Nintendo Wii Fit™ may provide an affordable alternative to traditional biofeedback or virtual reality systems for retraining or improving motor function in populations with impaired balance. The purpose of this study was to evaluate postural control strategies healthy individuals use to play Wii Fit™ videogames. Sixteen young adults played 10 trials of Ski Slalom and Soccer Heading respectively. Centre of pressure (COP) excursion and three-dimensional movement data were acquired to determine variability in medial-lateral COP sway and shoulder-pelvic movement. While there was no difference in medial-lateral COP variability between games during trial 1, there was a significant difference after 10 trials. COP sway increased (59-75 mm) for Soccer Heading while it decreased (67-33 mm) for Ski Slalom from trial 1 to trial 10. During Ski Slalom participants demonstrated decreased shoulder and pelvic movement combined with increased pelvic-shoulder coupling. Conversely, participants demonstrated greater initial shoulder tilt when playing Soccer Heading, with no reduction in pelvic rotation and tilt. Participants decreased pelvic and trunk movements when skiing, suggesting a greater contribution of lower extremity control while they primarily used a trunk strategy to play Soccer Heading. Copyright © 2012 Elsevier B.V. All rights reserved.

Girls Playing Soccer: Resistance or Submission? A Case Study of Women's Soccer in the ACT. A Report to the National Sports Research Centre, Australian Sports Commission.

ERIC Educational Resources Information Center

Traill, R. D.; And Others

This study identifies Australian girls' sports participation and variables associated with participation and dropping out. It describes the sporting experiences, and the decisions associated with those experiences, of a group of girls opposing traditional pressures by participating in a "male" sport (soccer). A survey was conducted of…

Intercollegiate soccer: saliva cortisol and testosterone are elevated during competition, and testosterone is related to status and social connectedness with team mates.

PubMed

Edwards, David A; Wetzel, Karen; Wyner, Dana R

2006-01-30

Men and women from a southern university's intercollegiate varsity soccer teams gave saliva samples before and after league matches. For the men, samples were collected for a single game ending in victory. For the women, samples were collected for two games, one of which ended in victory and the other in defeat. For both men and women, match competition substantially increased saliva cortisol (C) and testosterone (T). For women, play-related increases in saliva C and T were similar in victory and defeat. For both men and women, saliva T (but not C) was highly correlated with teammate ratings of playing abilities--one measure of status with teammates--and self-ratings of social connectedness with teammates, but the nature of the relationship was different according to sex. For men, play-related changes in T were positively correlated with these variables, but before-game T was not. For women, before-game T was positively related to each of these variables, but play-related changes in T were not. Status and social connectedness are pertinent to understanding interpersonal dynamics in most social groups, and these results--which link T and these variables in an athletic context--may have relevance for understanding social relationships in other settings.

Football match spectator sound exposure and effect on hearing: a pretest-post-test study.

PubMed

Swanepoel, De Wet; Hall, James W

2010-03-30

To determine (i) noise exposure levels of spectators at a FIFA 2010 designated training stadium during a premier soccer league match; and (ii) changes in auditory functioning after the match. This was a one-group pretest-post-test design of football spectators attending a premier soccer league match at a designated FIFA 2010 training stadium in Gauteng, South Africa. Individual spectator noise exposure for the duration of the football match and post-match changes in hearing thresholds were measured with pure-tone audiometry, and cochlear functioning was measured with distortion product oto-acoustic emissions (DPOAEs). The average sound exposure level during the match was 100.5 LAeq (dBA), with peak intensities averaging 140.4 dB(C). A significant (p=0.005) deterioration of post-match hearing thresholds was evident at 2 000 Hz, and post-match DPOAE amplitudes were significantly reduced at 1,266, 3,163 and 5,063 Hz (p=0.011, 0.019, 0.013, respectively). Exposure levels exceeded limits of permissible average and peak sound levels. Significant changes in post-match hearing thresholds and cochlear responsiveness highlight the possible risk for noise-induced hearing loss. Public awareness and personal hearing protection should be prioritized as preventive measures.

Risk factors for lower extremity injuries in elite female soccer players.

PubMed

Nilstad, Agnethe; Andersen, Thor Einar; Bahr, Roald; Holme, Ingar; Steffen, Kathrin

2014-04-01

The incidence of lower extremity injuries in female soccer players is high, but the risk factors for injuries are unknown. To investigate risk factors for lower extremity injuries in elite female soccer players. Cohort study; Level of evidence, 3. Players in the Norwegian elite female soccer league (N = 12 teams) participated in baseline screening tests before the 2009 competitive soccer season. The screening included tests assessing maximal lower extremity strength, dynamic balance, knee valgus angles in a drop-jump landing, knee joint laxity, generalized joint laxity, and foot pronation. Also included was a questionnaire to collect information on demographic data, elite-level experience, and injury history. Time-loss injuries and exposure in training and matches were recorded prospectively in the subsequent soccer season using weekly text messaging. Players reporting an injury were contacted to collect data regarding injury circumstances. Univariate and multivariate regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ±1 standard deviation of change. In total, 173 players underwent complete screening tests and registration of injuries and exposure throughout the season. A total of 171 injuries in 107 players (62%) were recorded; ligament and muscle injuries were the most frequent. Multivariate analyses showed that a greater body mass index (BMI) (OR, 1.51; 95% CI, 1.21-1.90; P = .001) was the only factor significantly associated with new lower extremity injuries. A greater BMI was associated with new thigh injuries (OR, 1.51; 95% CI, 1.08-2.11; P = .01), a lower knee valgus angle in a drop-jump landing was associated with new ankle injuries (OR, 0.64; 95% CI, 0.41-1.00; P = .04), and a previous knee injury was associated with new lower leg and foot injuries (OR, 3.57; 95% CI, 1.27-9.99; P = .02), whereas none of the factors investigated influenced the risk of new knee injuries. A greater BMI was associated with

Effects of Soccer Heading on Brain Structure and Function

PubMed Central

Rodrigues, Ana Carolina; Lasmar, Rodrigo Pace; Caramelli, Paulo

2016-01-01

Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered as an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of 6–12 incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years, some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the establishment of safety

Do cognitive training strategies improve motor and positive psychological skills development in soccer players? Insights from a systematic review.

PubMed

Slimani, Maamer; Bragazzi, Nicola Luigi; Tod, David; Dellal, Alexandre; Hue, Olivier; Cheour, Foued; Taylor, Lee; Chamari, Karim

2016-12-01

Soccer players are required to have well-developed physical, technical and cognitive abilities. The present systematic review, adhering to Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines, examined the effects of cognitive training strategies on motor and positive psychological skills development in soccer performance and identified the potential moderators of the "cognitive training-soccer performance" relationship. Thirteen databases were systematically searched using keywords related to psychological or cognitive training in soccer players. The review is based on 18 studies, employing 584 soccer players aged 7-39 years. Cognitive strategies, particularly imagery, appear to improve sports performance in soccer players. Regarding imagery, the combination of two different types of cognitive imagery training (i.e., cognitive general and cognitive specific) has a positive influence on soccer performance during training, whereas motivational imagery (i.e., motivational general-arousal, motivational general-mastery and motivational specific) enhance competition performance. Younger soccer players employ cognitive general and cognitive specific imagery techniques to a greater extent than older soccer players. Combined cognitive training strategies were more beneficial than a single cognitive strategy relative to motor skills enhancement in elite (particularly midfielders) and amateur (i.e., when practising complex and specific soccer skills in precompetitive period) soccer players. In conclusion, it appears that there are differences in cognitive/psychological training interventions, and their efficacy, according to whether they are directed towards training or competition, and the age, standard and playing position of the players.

Level of functional capacities following soccer-specific warm-up methods among elite collegiate soccer players.

PubMed

Vazini Taher, Amir; Parnow, Abdolhossein

2017-05-01

Different methods of warm-up may have implications in improving various aspects of soccer performance. The present study aimed to investigate acute effects of soccer specific warm-up protocols on functional performance tests. This study using randomized within-subject design, investigated the performance of 22 collegiate elite soccer player following soccer specific warm-ups using dynamic stretching, static stretching, and FIFA 11+ program. Post warm-up examinations consisted: 1) Illinois Agility Test; 2) vertical jump; 3) 30 meter sprint; 4) consecutive turns; 5) flexibility of knee. Vertical jump performance was significantly lower following static stretching, as compared to dynamic stretching (P=0.005). Sprint performance declined significantly following static stretching as compared to FIFA 11+ (P=0.023). Agility time was significantly faster following dynamic stretching as compared to FIFA 11+ (P=0.001) and static stretching (P=0.001). Knee flexibility scores were significantly improved following the static stretching as compared to dynamic stretching (P=016). No significant difference was observed for consecutive turns between three warm-up protocol. The present finding showed that a soccer specific warm-up protocol relied on dynamic stretching is preferable in enhancing performance as compared to protocols relying on static stretches and FIFA 11+ program. Investigators suggest that while different soccer specific warm-up protocols have varied types of effects on performance, acute effects of dynamic stretching on performance in elite soccer players are assured, however application of static stretching in reducing muscle stiffness is demonstrated.

Biochemical impact of soccer: an analysis of hormonal, muscle damage, and redox markers during the season.

PubMed

Silva, João Renato; Rebelo, António; Marques, Franklim; Pereira, Laura; Seabra, André; Ascensão, António; Magalhães, José

2014-04-01

This study aimed to analyze changes in performance, muscle function, and stress-related biochemical markers in professional soccer players (n = 14) at 4 timepoints (3 for performance and 4 for stress-related biochemical markers) during the soccer season [Formula: see text] preseason (E1), midseason (E2), end of the season (E3) [Formula: see text] and after the end of the recovery period (E4). Performance in 5- and 30-m sprints, countermovement jump, and agility, and maximal isokinetic knee extension and knee flexion strength were measured (E1 to E3). We observed increased in-season levels of myoglobin (E2 > E1 and E4; p < 0.05), a higher testosterone/cortisol ratio (T/C), and increased levels of creatine kinase (CK), C-reactive protein, superoxide dismutase (SOD), protein sulfhydryls (-SH), and malondialdehyde (E2 and E3 > E1 and E4; p < 0.05). Lower cortisol concentrations (E3 < E1 and E4; p < 0.05) and glutathione reductase activity (E3 < E2 and E4; p < 0.05) were observed at the end of the season. T/C, CK, SOD, -SH, and malondialdehyde decreased during the off-season, and cortisol and glutathione reductase increased (E3 < E4; p < 0.05). Agility increased in E2 and E3 (p < 0.01). Significant correlations were found during the season between hormonal and muscle function parameters (r = 0.56-0.86; p < 0.05). In addition, in E2, significant associations were observed between match-accumulated time (MATE2; minutes played by each player during the competition period), performance, and hormonal and redox parameters (r = 0.456-0.615; p < 0.05). In conclusion, this study shows that soccer players face significant changes in biomarkers of physiologic strain (muscle damage and oxidative stress-related markers) during the season, but values return to normal during the off-season. Additionally, MAT influences physical, hormonal, and oxidative stress-related parameters in professional soccer players.

Fluctuations in running and skill-related performance in elite rugby union match-play.

PubMed

Lacome, Mathieu; Piscione, Julien; Hager, Jean-Philippe; Carling, Chris

2017-03-01

This study investigated end-game and transient changes in running activities and whether these were concomitantly associated with reductions in skill-related performance in senior international rugby union match-play. Altogether, 18 official matches were analysed (322 individual observations) using computerised video-based tracking and event coding (Amisco Pro ® , SUP, Nice, France). In forwards and backs, trivial to small reductions (% difference: -2.1, ±1.3 to -10.0, ±4.0%) in total distance and that covered at high speeds (>18.0 km h -1 ) occurred in the second- versus the first-half while there were trivial differences in skill-related performance measures (-2.3, ±4.5 to 7.5, ±14.0%). In both positions, small to moderate declines (-42, ±10 to -21, ±7%) occurred in high-speed running in the final 10-min and 5-min periods versus mean values for all other 10-min and 5-min periods throughout the game while only small changes (-18, ±51 to 13, ±41%) in skill-related performance were observed. Trivial changes in running and skill-related performance (-11, ±74 to 7, ±39%) were observed in the 5-min period immediately following the most intense 5-minute periods of play compared to mean performance over the other 5-min periods. These findings suggest that international rugby union players were generally able to maintain skill-related performance over the course of match-play even when declines in running performance occurred.

Bone properties in child and adolescent male hockey and soccer players.

PubMed

Falk, Bareket; Braid, Sarah; Moore, Michael; Yao, Matthew; Sullivan, Phil; Klentrou, Nota

2010-07-01

Children and adolescents who train extensively in high-impact, weight-bearing activities have enhanced bone mineral density. The purpose of this study was to evaluate bone strength, as reflected by quantitative ultrasound (QUS, Sunlight Omniscence), of child (10-12 yrs old) and adolescent (14-16 yrs old) male soccer and hockey players in comparison with age-matched controls. The groups included 30 child (CH) and 31 adolescent (AH) hockey players, 26 child (CS) and 30 adolescent (AS) soccer players, as well as 34 child (CC) and 31 adolescent (AC) healthy, non-athletic, age-matched controls. All athletes trained at an elite level year-round, with no difference in training volume between groups. Ultrasound speed of sound (SOS) was measured at the distal-radius and mid-tibia. In both age groups, hockey players were the heaviest and had the highest fat-free mass. No differences were found among groups in total energy intake, calcium or vitamin D intake. Radial and tibial SOS increased with age. Hockey players had higher radial SOS in both age groups (children: CH:3763+/-74, CS:3736+/-77, CC:3721+/-88 m/s; adolescents: AH:3809+/-105, AS:3767+/-85, AC:3760+/-94 m/s). Tibial SOS was higher in soccer players compared with controls. In spite of the higher body mass and fat-free mass in hockey players, their tibial SOS was similar to the non-athletes in both age groups. These findings support previous suggestions of sport-specific effects on bone strength. However, they need to be corroborated with longitudinal or prospective intervention studies. Copyright 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Talent identification in youth soccer.

PubMed

Unnithan, Viswanath; White, Jordan; Georgiou, Andreas; Iga, John; Drust, Barry

2012-01-01

The purpose of this review article was firstly to evaluate the traditional approach to talent identification in youth soccer and secondly present pilot data on a more holistic method for talent identification. Research evidence exists to suggest that talent identification mechanisms that are predicated upon the physical (anthropometric) attributes of the early maturing individual only serve to identify current performance levels. Greater body mass and stature have both been related to faster ball shooting speed and vertical jump capacity respectively in elite youth soccer players. This approach, however, may prematurely exclude those late maturing individuals. Multiple physiological measures have also been used in an effort to determine key predictors of performance; with agility and sprint times, being identified as variables that could discriminate between elite and sub-elite groups of adolescent soccer players. Successful soccer performance is the product of multiple systems interacting with one another. Consequently, a more holistic approach to talent identification should be considered. Recent work, with elite youth soccer players, has considered whether multiple small-sided games could act as a talent identification tool in this population. The results demonstrated that there was a moderate agreement between the more technically gifted soccer player and success during multiple small-sided games.

[Mass casualty incidents : preparedness of German soccer arenas].

PubMed

Luiz, T; Preisegger, T; Madler, C

2013-04-01

Each weekend soccer arenas attract hundreds of thousands of spectators with the German Bundesliga being one of the most attractive sport series worldwide. In 2006 when the FIFA soccer World Cup™ took place in Germany, the precautions in the participating arenas against mass casualty incidents (MCI) reached a level formerly unknown in Germany. However, it is unknown how soccer arenas are prepared to deal with such incidents in everyday life. In 2011 all German major soccer league clubs were questioned about medical precautions in case of MCIs occurring in the stadium. The questionnaire included the following items: stadium capacity, the number of paramedic personnel, emergency physicians and ambulance vehicles, the command and communication structures, the availability of MCI plans, recent MCI drills and the frequency of MCI. Out of 39, 15 (38.4 %) participated, 50 % from the first league and 20.8 % from the second league. The mean stadium capacity was 41,800 spectators (minimum 10,600, maximum 80,700). Depending on the number of spectators and the individual risk score of the match the following resources were available within the stadiums (average, minimum, maximum,): emergency medical technicians 61-67 (15, 120), emergency physicians 2.3-2.5 (1, 5) and transport capacity 5.3-5.8 patients (1, 15). In 14 arenas (93.3 %) the medical personnel were trained in mass casualty care and had prepared MCI operation schedules. All stadiums had mission control centers equipped with a variety of wired and wireless communication tools, although only eight (52.3 %) arenas used a joint command structure and five (33.3 %) arenas reported MCIs (defined as a scenario involving more than 10 patients) within the past 10 years. In 40 % of the participants the last MCI-related exercise was conducted more than 36 months ago. Most of the participating arenas were adequately staffed to manage the first phase of MCIs but in contrast command structures and transport capacities often

Methods of the international study on soccer at altitude 3600 m (ISA3600)

PubMed Central

Gore, Christopher J; Aughey, Robert J; Bourdon, Pitre C; Garvican-Lewis, Laura A; Soria, Rudy; Claros, Jesus C Jimenez; Sargent, Charli; Roach, Gregory D; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Pepper, Mark; Edwards, Alistair; Cuenca, Douglas; Vidmar, Tony; Spielvogel, Hilde; Schmidt, Walter F

2013-01-01

Background We describe here the 3-year process underpinning a multinational collaboration to investigate soccer played at high altitude—La Paz, Bolivia (3600 m). There were two main aims: first, to quantify the extent to which running performance would be altered at 3600 m compared with near sea level; and second, to characterise the time course of acclimatisation of running performance and underlying physiology to training and playing at 3600 m. In addition, this project was able to measure the physiological changes and the effect on running performance of altitude-adapted soccer players from 3600 m playing at low altitude. Methods A U20 Bolivian team (‘The Strongest’ from La Paz, n=19) played a series of five games against a U17 team from sea level in Australia (The Joeys, n=20). 2 games were played near sea level (Santa Cruz 430 m) over 5 days and then three games were played in La Paz over the next 12 days. Measures were (1) game and training running performance—including global positioning system (GPS) data on distance travelled and velocity of movement; (2) blood—including haemoglobin mass, blood volume, blood gases and acid–base status; (3) acclimatisation—including resting heart rate variability, perceived altitude sickness, as well as heart rate and perceived exertion responses to a submaximal running test; and (4) sleep patterns. Conclusions Pivotal to the success of the project were the strong professional networks of the collaborators, with most exceeding 10 years, the links of several of the researchers to soccer federations, as well as the interest and support of the two head coaches. PMID:24282214

Influence of field position and phase of play on the physical demands of match-play in professional rugby league forwards.

PubMed

Gabbett, Tim J; Polley, Chris; Dwyer, Dan B; Kearney, Simon; Corvo, Alex

2014-09-01

No study has investigated the influence of field position and phase of play on the physical demands of match-play in professional rugby league forwards. We investigated the physical demands placed on forwards in elite rugby league matches, with special reference to how these demands differed between attack and defence, and in different field positions. Cohort study. Twenty-two rugby league players (26 ± 3 years) from the same professional club participated in this study. Global positioning system (GPS) analysis was completed during 23 matches. Video footage was synchronised with the GPS files and coded for the time spent in attack and defence, and in one of three different field positions (0-30 m, 31-70 m, 71-100 m). The physical demands of defence were consistently greater than attack. Moderate to large differences (ES=0.62-1.41) were found between defence and attack for distance covered (109 ± 16 m/min vs. 82 ± 12 m/min), low speed distance (104 ± 15 m/min vs. 78 ± 11 m/min), frequency of collisions (1.9 ± 0.7/min vs. 0.8 ± 0.3/min), and repeated high-intensity effort bouts (1 every 4.9 ± 5.1 min vs. 1 every 9.4 ± 6.1 min). The running demands and frequency of repeated high-intensity effort bouts were greater when defending in the opposition's 30 m zone (i.e. 71-100 m), with repeated high-intensity effort bouts also occurring more frequently when defending the team's own try-line and when attacking the opposition's try-line. Specific training drills designed to replicate the attacking and defensive demands of different field positional zones are likely to be effective in preparing players for the most demanding activities that occur in professional rugby league match-play. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Soccer; Speedball; Flag Football, June 1976--June 1978. NAGWS Guide.

ERIC Educational Resources Information Center

Messing, Anne, Ed.; And Others

This guide for soccer, speedball, and flag football is one in a series of guides for 22 sports published by the National Association for Girls and Women in Sport (NAGWS). Guides contain information on NAGWS-approved playing rules, officials' ratings, articles on teaching, coaching and organization, rules governing national championships,…

Does eccentric training of hamstring muscles reduce acute injuries in soccer?

PubMed

Nichols, Andrew W

2013-01-01

To investigate the effectiveness of a 10-week hamstring exercise training program in reducing the incidence and severity of new and recurrent hamstring injuries among male soccer players. Cluster-randomized (by team)controlled trial, stratified by level of play and geographic location. Sample size was calculated with 80% power to show a relative risk reduction for injury of 50% at P ≤ 0.05. Soccer community study in Denmark during the period January to December 2008. Teams in the top 5 soccer divisions (2 professional and 3 amateur)were invited to participate. The exclusion criterion for teams was that they already used eccentric hamstring exercises, and for participants was that they joined the teams after the beginning of the season. Of 116 teams, 54 were eligible and willing to be randomized and 50 were included in the analysis (942 players). Teams in both the intervention and control groups followed their normal training programs. At the beginning of the study period, the intervention teams added 27 sessions of the Nordicham string exercise (after warm-up) during the 10-week period of the mid-season break. The exercise begins with the player kneeling with the torso upright and rigid, and the feet held down to the ground by a partner. The player lowers his torso forwards toward the ground braking with his hamstring muscles until the chest reaches the ground (eccentric phase). He returns to the upright position, pushing with his hands to minimize the concentric phase load. Sessions per week and sets and repetitions per session increased to 3, 3, and 12, respectively. Team coaches supervised the sessions. A hamstring injury was defined as an acute occurrence of a “physical complaint in the region of the posterior thigh sustained during a soccer match or training, irrespective of the need for medical attention or time loss from soccer activities.” Injuries were recorded by the teams’ medical staff on standardized forms. Only first injuries during the season

Analysis of Reaction Times and Aerobic Capacities of Soccer Players According to Their Playing Positions

ERIC Educational Resources Information Center

Taskin, Cengiz; Karakoc, Onder; Taskin, Mine; Dural, Murat

2016-01-01

70 soccer players in Gaziantep amateur league voluntarily participated in this study, (average of their ages 19,17±1,34years, average of their heights 181,28±5,06 cm, average of their body weights 76,75±4,43 kg and average of their sports experiences 3,78±0,95 years) to analyze visual and auditory reaction times and aerobic capacities of amateur…

Effect of ACTN3 gene on strength and endurance in soccer players.

PubMed

Pimenta, Eduardo M; Coelho, Daniel B; Veneroso, Christiano E; Barros Coelho, Ering J; Cruz, Izinara R; Morandi, Rodrigo F; De A Pussieldi, Guilherme; Carvalho, Maria R S; Garcia, Emerson S; De Paz Fernández, José A

2013-12-01

Sports efficiency in activities in which strength and speed are the determining factors has been associated to the ACTN3 gene, which is responsible for the expression of α-actinin-3. Soccer is a mainly aerobic sport because of its long duration, but the acute actions that define the game demand a lot of strength and speed. The purpose of the present study was to compare the performance capacity of soccer players with different genotype groups of ACTN3 (XX, RX, and RR) in strength, speed, and endurance tests. Two hundred professional players of Brazilian soccer first division teams participated in this study. Speed, jump, and endurance test results were compared with the polymorphisms of the ACTN3 gene. It was noticed that RR individuals spent less time to run a 10-m path, compared with XX individuals (p < 0.05). The RR individuals also presented lower time rates at the 20- and 30-m path, compared with RX and XX individuals (p < 0.05). In jump tests, RR individuals presented higher rates, compared with RX and XX individuals (p < 0.05). As for aerobic tests, the XX individuals presented higher rates of V[Combining Dot Above]O2 max, compared with the RR group (p < 0.05), and did not differ from the RX group. The main conclusion of this study is that soccer players of genotype ACTN3/RR are the fastest in short distances and present higher jump potential. ACTN3/XX individuals presented the highest aerobic capacity. These findings can be used in training load adjustment and can influence the development of tactical schemes in soccer matches.

Exercise‐induced homeostatic perturbations provoked by singles tennis match play with reference to development of fatigue

PubMed Central

Mendez‐Villanueva, Alberto; Fernandez‐Fernandez, Jaime; Bishop, David

2007-01-01

This review addresses metabolic, neural, mechanical and thermal alterations during tennis match play with special focus on associations with fatigue. Several studies have provided a link between fatigue and the impairment of tennis skills proficiency. A tennis player's ability to maintain skilled on‐court performance and/or optimal muscle function during a demanding match can be compromised as a result of several homeostatic perturbations, for example hypoglycaemia, muscle damage and hyperthermia. Accordingly, an important physiological requirement to succeed at competitive level might be the player's ability to resist fatigue. However, research evidence on this topic is limited and it is unclear to what extent players experience fatigue during high‐level tennis match play and what the physiological mechanisms are that are likely to contribute to the deterioration in performance. PMID:17957005

A four year prospective study of injuries in elite Ontario youth provincial and national soccer players during training and matchplay

PubMed Central

Mohib, Milad; Moser, Nicholas; Kim, Richard; Thillai, Maathavan; Gringmuth, Robert

2014-01-01

Introduction: With over 200 million amateur players worldwide, soccer is one of the most popular and internationally recognized sports today. By understanding how and why soccer injuries occur we hope to reduce prevalent injuries amongst elite soccer athletes. Methods: Via a prospective cohort, we examined both male and female soccer players eligible to train with the Ontario Soccer Association provincial program between the ages of 13 to 17 during the period of October 10, 2008 and April 20, 2012. Data collection occurred during all player exposures to potential injury. Exposures occurred at the Soccer Centre, Ontario Training grounds and various other venues on multiple playing surfaces. Results: A total number of 733 injuries were recorded. Muscle strain, pull or tightness was responsible for 45.6% of all injuries and ranked as the most prevalent injury. Discussion: As anticipated, the highest injury reported was muscular strain, which warrants more suitable preventive programs aimed at strengthening and properly warming up the players’ muscles. PMID:25550661

Match-play demands of elite youth Gaelic football using global positioning system tracking.

PubMed

Reilly, Brian; Akubat, Ibrahim; Lyons, Mark; Collins, D Kieran

2015-04-01

Global positioning systems (GPS) technology has made athlete-tracking a convenient and accepted technique to specify movement patterns and physical demands in sport. The purpose of this study was to examine positional demands of elite youth Gaelic football match-play using portable GPS technology to examine movement patterns and heart rates across match periods. Fifty-six elite youth male Gaelic footballers (age, 15 ± 0.66 years) fitted with portable 4-Hz GPS units were observed during 6 competitive matches (60 minutes). Data provided from the GPS unit included total distance, high-intensity (≥17·km·h(-1)) distance, sprint (≥22 km·h(-1)) distance, and total number of sprints. Heart rate was monitored continuously throughout the games. Players covered a mean distance of 5732 ± 1047 m, and the mean intensity of match-play was 85% of the peak heart rate. There was a significant (p = 0.028) drop in the total distance covered in the second half (2783 ± 599 m) compared with the first half (2948 ± 580 m). In particular, there is a noticeable drop in the distance covered in the third quarter of the game (after half-time), which has implications for re-warming up at the end of the half-time interval. There was a highly significant (p < .001) difference in the distance traveled across the 5 positional groups with midfielders covering the greatest total distance (6740 ± 384 m). The significant differences found with respect to positional groups support the implementation of individual, position-specific strength and conditioning programs.

A preliminary examination of neurocognitive performance and symptoms following a bout of soccer heading in athletes wearing protective soccer headbands.

PubMed

Elbin, R J; Beatty, Amanda; Covassin, Tracey; Schatz, Philip; Hydeman, Ana; Kontos, Anthony P

2015-01-01

This study compared changes in neurocognitive performance and symptom reports following an acute bout of soccer heading among athletes with and without protective soccer headgear. A total of 25 participants headed a soccer ball 15 times over a 15-minute period, using a proper linear heading technique. Participants in the experimental group completed the heading exercise while wearing a protective soccer headband and controls performed the heading exercise without wearing the soccer headband. Neurocognitive performance and symptom reports were assessed before and after the acute bout of heading. Participants wearing the headband showed significant decreases on verbal memory (p = 0.02) compared with the no headband group, while the no headband group demonstrated significantly faster reaction time (p = 0.03) than the headband group following the heading exercise. These findings suggest that protective soccer headgear likely does not mitigate the subtle neurocognitive effects of acute soccer heading.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020368 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Steve Swanson, commander, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020364 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Steve Swanson, commander, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020361 (26 June 2014) --- NASA astronaut Steve Swanson (right), Expedition 40 commander; and European Space Agency astronaut Alexander Gerst, flight engineer, enjoy a light moment in the Unity node of the International Space Station. Gerst is holding hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020378 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020383 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020384 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

The application of the Yo-Yo intermittent endurance level 2 test to elite female soccer populations.

PubMed

Bradley, P S; Bendiksen, M; Dellal, A; Mohr, M; Wilkie, A; Datson, N; Orntoft, C; Zebis, M; Gomez-Diaz, A; Bangsbo, J; Krustrup, P

2014-02-01

The aim of this study was to evaluate the application of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2) to elite female soccer populations. Elite senior (n = 92), youth (n = 42), domestic (n = 46) and sub-elite female soccer players (n = 19) carried out the Yo-Yo IE2 test on numerous occasions across the season. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance in domestic female players was 4.5%. Elite senior female players' Yo-Yo IE2 test performances were better (P < 0.01) than elite youth, domestic and sub-elite players (mean ± standard deviation; 1774 ± 532 vs 1490 ± 447, 1261 ± 449, and 994 ± 373 m). For elite senior female players, wide midfielders (2057 ± 550 m) had a higher Yo-Yo IE2 test performance (P < 0.05) than central defenders (1588 ± 534 m) and attackers (1516 ± 401 m), but not central midfielders (1764 ± 473 m) or full-backs (1964 ± 522 m). Large correlations were observed between Yo-Yo IE2 test performance and the total and high-intensity distance covered (r = 0.55; P < 0.05) during elite senior soccer matches (r = 0.70; P < 0.01). A large correlation was also obtained between Yo-Yo IE2 test performance and (r = 0.68; P < 0.01). Performances in the Yo-Yo IE2 test were greater (P < 0.05) in the middle and the end of the season compared with the preparation period for elite youth female players (1767 ± 539 and 1742 ± 503 vs 1564 ± 504 m) and in elite senior female players, Yo-Yo IE2 test performance increased by 14% (P < 0.01) after completing 4 weeks of intense training prior to the FIFA Women's World Cup Finals (2049 ± 283 vs 1803 ± 342 m). The data demonstrate that the Yo-Yo IE2 test is reproducible and is an indicator of the match-specific physical capacity of female soccer players. Furthermore, the Yo-Yo IE2 test illustrates sensitivity by differentiating

Sudden cardiac death in the soccer field: a retrospective study in young soccer players from 2000 to 2013.

PubMed

Davogustto, Giovanni; Higgins, John

2014-11-01

Soccer is the most popular sport in the world, with over 200 million active players. Sudden cardiac death (SCD) represents the most striking as well as the most common cause of death in the soccer field. Underlying cardiovascular pathologies predispose to life threatening ventricular arrhythmias and SCD in soccer players. Up to thousands to hundred thousands players might have an underlying condition that predisposes them for SCD. After several media striking SCD events in soccer players the Fédération Internationale de Football Association (FIFA) has made screening recommendations that are more thorough than the ones recommended for the American Heart Association and the European Society of Cardiology. We present a retrospective search through Internet databases that resulted in 54 soccer players with SCD events from 2000 until 2013. In this article, we will describe and discuss the conditions of those cases of SCD in order to provide more knowledge of the factors that may precipitate SCD in young soccer players.

Return to sports after arthroscopic capsulolabral repair using knotless suture anchors for anterior shoulder instability in soccer players: minimum 5-year follow-up study.

PubMed

Alentorn-Geli, Eduard; Álvarez-Díaz, Pedro; Doblas, Jesús; Steinbacher, Gilbert; Seijas, Roberto; Ares, Oscar; Boffa, Juan José; Cuscó, Xavier; Cugat, Ramón

2016-02-01

To report the return to sports and recurrence rates in competitive soccer players after arthroscopic capsulolabral repair using knotless suture anchors at a minimum of 5 years of follow-up. All competitive soccer players with anterior glenohumeral instability treated by arthroscopic capsulolabral repair using knotless suture anchors between 2002 and 2009 were retrospectively identified through the medical records. Inclusion criteria were: no previous surgical treatment of the involved shoulder, absence of glenoid or tuberosity fractures, absence of large Hill-Sachs or glenoid bone defect, minimum follow-up of 5 years, instability during soccer practice or games, and failure of non-surgical treatment. The charts of included players were reviewed, and a phone call was performed in a cross-sectional manner to obtain information on: current soccer, return to soccer, recurrence of instability, shoulder function (Rowe score), and disability [Quick-Disability of the Arm, Shoulder, and Hand (DASH) score and Quick-DASH Sports/Performing Arts Module]. Fifty-seven young male soccer players were finally included with a median (range) follow-up of 8 (5-10) years. Forty-nine (86 %) of the soccer players were able to return to soccer and 36 of them (73 %) at the same pre-injury level. There were 6 (10.5 %) re-dislocations in the 57 players, all of them of traumatic origin produced during soccer and other unrelated activities. The main reasons to not return to soccer were: knee injuries (two players), changes in personal life (two players), and job-related (three players). None of the players quit playing soccer because of their shoulder instability injury. The median (range) Rowe score, Quick-DASH score, and Quick-DASH sports score were 80 (25-100), 2.3 (0-12.5), and 0 (0-18.8), respectively. Competitive soccer players undergoing arthroscopic capsulolabral repair with knotless suture anchors for shoulder instability without significant bone loss demonstrate excellent return to

Leg Stiffness in Female Soccer Players: Intersession Reliability and the Fatiguing Effects of Soccer-Specific Exercise.

PubMed

De Ste Croix, Mark B A; Hughes, Jonathan D; Lloyd, Rhodri S; Oliver, Jon L; Read, Paul J

2017-11-01

De Ste Croix, MBA, Hughes, JD, Lloyd, RS, Oliver, JL, and Read, PJ. Leg stiffness in female soccer players: intersession reliability and the fatiguing effects of soccer-specific exercise. J Strength Cond Res 31(11): 3052-3058, 2016-Low levels of leg stiffness and reduced leg stiffness when fatigue is present compromise physical performance and increase injury risk. The purpose of this study was to (a) determine the reliability of leg stiffness measures obtained from contact mat data and (b) explore age-related differences in leg stiffness after exposure to a soccer-specific fatigue protocol in young female soccer players. Thirty-seven uninjured female youth soccer players divided into 3 subgroups based on chronological age (under 13 [U13], under 15 [U15], and under 17 [U17] year-olds) volunteered to participate in the study. After baseline data collection, during which relative leg stiffness, contact time, and flight time were collected, participants completed an age-appropriate soccer-specific fatigue protocol (SAFT). Upon completion of the fatigue protocol, subjects were immediately retested. Intersession reliability was acceptable and could be considered capable of detecting worthwhile changes in performance. Results showed that leg stiffness decreased in the U13 year-olds, was maintained in the U15 age group, and increased in the U17 players. Contact times and flight times did not change in the U13 and U15 year-olds, but significantly decreased and increased, respectively, in the U17 age group. The data suggest that age-related changes in the neuromuscular control of leg stiffness are present in youth female soccer players. Practitioners should be aware of these discrepancies in neuromuscular responses to soccer-specific fatigue, and should tailor training programs to meet the needs of individuals, which may subsequently enhance performance and reduce injury risk.

Match play demands of 11 versus 11 professional football using Global Positioning System tracking: Variations across common playing formations.

PubMed

Tierney, Peter J; Young, Andrew; Clarke, Neil D; Duncan, Michael J

2016-10-01

This study aimed to examine Global Positioning System (GPS) determined movement patterns across the 5 most common playing formations (4-4-2; 4-3-3; 3-5-2; 3-4-3; 4-2-3-1) employed in 11 versus 11 football match play in England. Elite male footballers (n=46) were monitored over the course of a season; total distance (TD), high speed running (HSR), high metabolic load distance (HMLD), high speed accelerations (Acc) and decelerations (Dec) data was collected for analysis. It was found that 3-5-2 formation elicited higher TD (10528±565m, p=0.05), HSR (642±215m, p=0.001), and HMLD (2025±304m, p=0.001) than all other formations and above average Acc and Dec (34±7, p=0.036 and 57±10, p=0.006), with 4-2-3-1 eliciting the highest Acc and Dec (38±8 and 61±12). Positional data showed that CM in 4-3-3 covered >11% TD than in 4-4-2 (p=0.012). FW in 3-5-2 covered >45% HSR than in 4-2-3-1 (p=0.004). CM in 4-3-3 covered >14% HMLD than in 4-4-2 (p=0.367). FW in 4-3-3 performed >49% accelerations than in 4-2-3-1 (p=0.293). WD in 3-5-2 performed >20% more decelerations than in 4-4-2 (p=0.161). This study is important for coaches understanding, that positional physical characteristics are influenced by the demands of playing in different formations during match play. Copyright © 2016 Elsevier B.V. All rights reserved.

Are Female Soccer Players at an Increased Risk of Second Anterior Cruciate Ligament Injury Compared With Their Athletic Peers?

PubMed

Allen, Melissa M; Pareek, Ayoosh; Krych, Aaron J; Hewett, Timothy E; Levy, Bruce A; Stuart, Michael J; Dahm, Diane L

2016-10-01

Female soccer players have a well-known risk for anterior cruciate ligament (ACL) injury, but few studies have reported on second ACL injuries in this population. To (1) report the rates of subsequent ACL injury (ipsilateral graft rupture or contralateral tear) in competitive female soccer players, (2) compare these rates with those of other female athletes of similar competitive level, (3) determine risk factors for second ACL injury, and (4) report clinical outcome scores in this population. Cohort study; Level of evidence, 3. The medical records at a single institution were reviewed for female patients who were injured during a competitive athletic event and treated with primary ACL reconstruction (ACLR) between 1998 and 2013. Patients were followed for a mean of 68.8 months postoperatively (range, 24-115.2 months). Clinical outcome was obtained via Lysholm and International Knee Documentation Committee (IKDC) scores. Soccer players were matched 1:1 to non-soccer athletes for age, activity level, and graft type. A total of 180 female ACLR patients with a mean ± SD age of 19.6 ± 6.9 years met the study inclusion and exclusion criteria (90 soccer players and 90 non-soccer players). Soccer players sustained more second ACL injuries, including both graft failures (11% vs 1%; P < .01) and contralateral ACL tears (17% vs 4%; P < .01), compared with non-soccer players. Of the 67 patients who returned to soccer after ACLR (mean age, 17.5 years; range, 13-27 years), significantly more had graft tears compared with those who did not return to soccer (15% vs 0%, respectively; P = .04); however, the difference in contralateral ACL tears (19% for returning players vs 9% for those who did not return; P = .34) was not significant. Relatively older age (odds ratio, 1.5 per year; P = .03) was a significant risk factor for ACL graft tear but not for contralateral ACL injury. Both groups had similar mean Lysholm (96 vs 95) and IKDC scores (95 vs 96) at final follow-up. Twenty

Coach Mid-Season Replacement and Team Performance in Professional Soccer

PubMed Central

Lago-Peñas, Carlos

2011-01-01

The coaching carousel or turnover is an extreme but frequently occurring phenomenon in soccer. Among the reasons for firing a coach, the most common is the existence of a shock-effect: a new coach would be able to motivate the players better and therefore to improve results. Using data from the Spanish Soccer League during the seasons from 1997–1998 to 2006–2007, this paper investigates the relationship between team performance and coach change over time. The empirical analysis shows that the shock effect of a turnover has a positive impact on team performance in the short term. Results reveal no impact of coach turnover in the long term. The favourable short-term impact on team performance of a coach turnover is followed by continued gradual worsening of results. The turnover effect is nonexistent when the comparison between the new coach and the old coach is done over 10, 15 or 20 matches before and after termination. PMID:23487177

Coach mid-season replacement and team performance in professional soccer.

PubMed

Lago-Peñas, Carlos

2011-06-01

The coaching carousel or turnover is an extreme but frequently occurring phenomenon in soccer. Among the reasons for firing a coach, the most common is the existence of a shock-effect: a new coach would be able to motivate the players better and therefore to improve results. Using data from the Spanish Soccer League during the seasons from 1997-1998 to 2006-2007, this paper investigates the relationship between team performance and coach change over time. The empirical analysis shows that the shock effect of a turnover has a positive impact on team performance in the short term. Results reveal no impact of coach turnover in the long term. The favourable short-term impact on team performance of a coach turnover is followed by continued gradual worsening of results. The turnover effect is nonexistent when the comparison between the new coach and the old coach is done over 10, 15 or 20 matches before and after termination.

Impact of Ramadan on physical performance in professional soccer players

PubMed Central

Zerguini, Yacine; Kirkendall, Donald; Junge, Astrid; Dvorak, Jiri

2007-01-01

Objective Ramadan is a period of daylight abstention from liquid or solid nutrients. As sports continue to be scheduled, an understanding of the effects of Ramadan on Muslim athletes is warranted. Design Two Algerian professional soccer teams (55 men) were studied. Field tests of physical and soccer performance were collected before, at the end and 2 weeks after Ramadan in 2004. Players were queried on sleeping habits and personal perception of training and match performance. Setting Field setting at club training ground. Main outcome measures Performance on fitness and skill tests. Results Performance declined significantly (p<0.05) for speed, agility, dribbling speed and endurance, and most stayed low after the conclusion of Ramadan. Nearly 70% of the players thought that their training and performance were adversely affected during the fast. Conclusions The phase shift of food intake and disruption of sleep patterns affect actual and perceived physical performance. Islamic athletes need to explore strategies that will maximise performance during Ramadan. PMID:17224435

Strong correlation of maximal squat strength with sprint performance and vertical jump height in elite soccer players

PubMed Central

Wisloff, U; Castagna, C; Helgerud, J; Jones, R; Hoff, J

2004-01-01

Background: A high level of strength is inherent in elite soccer play, but the relation between maximal strength and sprint and jumping performance has not been studied thoroughly. Objective: To determine whether maximal strength correlates with sprint and vertical jump height in elite male soccer players. Methods: Seventeen international male soccer players (mean (SD) age 25.8 (2.9) years, height 177.3 (4.1) cm, weight 76.5 (7.6) kg, and maximal oxygen uptake 65.7 (4.3) ml/kg/min) were tested for maximal strength in half squats and sprinting ability (0–30 m and 10 m shuttle run sprint) and vertical jumping height. Result: There was a strong correlation between maximal strength in half squats and sprint performance and jumping height. Conclusions: Maximal strength in half squats determines sprint performance and jumping height in high level soccer players. High squat strength did not imply reduced maximal oxygen consumption. Elite soccer players should focus on maximal strength training, with emphasis on maximal mobilisation of concentric movements, which may improve their sprinting and jumping performance. PMID:15155427

Match-play activity profile in elite women's rugby union players.

PubMed

Suarez-Arrones, Luis; Portillo, Javier; Pareja-Blanco, Fernando; Sáez de Villareal, Eduardo; Sánchez-Medina, Luis; Munguía-Izquierdo, Diego

2014-02-01

The aim of this study was to provide an objective description of the locomotive activities and exercise intensity undergone during the course of an international-level match of female rugby union. Eight players were analyzed using global positioning system tracking technology. The total distance covered by the players during the whole match was 5,820 ± 512 m. The backs covered significantly more distance than the forwards (6,356 ± 144 vs. 5,498 ± 412 m, respectively). Over this distance, 42.7% (2,487 ± 391 m) was spent standing or walking, 35% jogging (2,037 ± 315 m), 9.7% running at low intensity (566 ± 115 m), 9.5% at medium intensity (553 ± 190 m), 1.8% at high intensity (105 ± 74 m), and 1.2% sprinting (73 ± 107 m). There were significant differences in the distance covered by forwards and backs in certain speed zones. Analysis of the relative distance traveled over successive 10-minute period of match play revealed that the greatest distances were covered during the first (725 ± 53 m) and the last (702 ± 79 m) 10-minute period of the match. The average number of sprints, the average maximum distance of sprinting, the average minimum distance of sprinting, and the average sprint distance during the game were 4.7 ± 3.9 sprints, 20.6 ± 10.5 m, 5.8 ± 0.9 -m, and 12.0 ± 3.8 m, respectively. There were substantial differences between forwards and backs. Backs covered greater total distance, distance in certain speed zones, and sprinting performance. The players spent 46.9 ± 28.9% of match time between 91 and 100% of maximum heart rate and experienced a large number of impacts (accelerometer data and expressed as g forces) during the game. These findings offer important information to design better training strategies and physical fitness testing adapted to the specific demands of female rugby union.

Sports injuries profile of a first division Brazilian soccer team: a descriptive cohort study.

PubMed

Reis, Guilherme F; Santos, Thiago R T; Lasmar, Rodrigo C P; Oliveira Júnior, Otaviano; Lopes, Rômulo F F; Fonseca, Sérgio T

2015-01-01

To establish the injury profile of soccer players from a first division Brazilian soccer team. In addition, we investigated the association between the characteristics of the injuries and the player's age and position. Forty-eight players from a Brazilian first division soccer team were followed during one season. Descriptive statistics were used to characterize the injury profile. Spearman's tests were used to verify the association between the number and severity of injuries and the player's age. Chi-square test was used to verify the association between type of injury and player's position. Fisher's exact test was used to verify the association between the severity of injuries and player's position. The incidence of injuries was 42.84/1000 hours in matches and 2.40/1000 hours in training. The injury severity was 19.5±34.4 days off competition or training. Lower limb was the most common location of injury and most injuries were muscular/tendinous, overuse, non-recurrent, and non-contact injuries. Player's age correlated with the amount and severity of muscle and tendon injuries. Defenders had more minimal injuries (1-3 days lost), while forwards had more moderate (8-28 days lost) and severe injuries (>28 days lost). Furthermore, wingbacks had more muscle and tendon injuries, while midfielders had more joint and ligament injuries. The injury profile of the Brazilian players investigated in this study reflected regional differences in soccer practices. Results confirm the influence of the player's age and position on the soccer injuries profile.

Season-long increases in perceived muscle soreness in professional rugby league players: role of player position, match characteristics and playing surface.

PubMed

Fletcher, Ben D; Twist, Craig; Haigh, Julian D; Brewer, Clive; Morton, James P; Close, Graeme L

2016-01-01

Rugby League (RL) is a high-impact collision sport characterised by repeated sprints and numerous high-speed impacts and consequently players often report immediate and prolonged muscle soreness in the days after a match. We examined muscle soreness after matches during a full season to understand the extent to which match characteristics influence soreness. Thirty-one elite Super League players provided daily measures of muscle soreness after each of the 26 competitive fixtures of the 2012 season. Playing position, phase of the season, playing surface and match characteristics were recorded from each match. Muscle soreness peaked at day 1 and was still apparent at day 4 post-game with no attenuation in the magnitude of muscle soreness over the course of the season. Neither playing position, phase of season or playing surface had any effects on the extent of muscle soreness. Playing time and total number of collisions were significantly correlated with higher ratings of muscle soreness, especially in the forwards. These data indicate the absence "contact adaptations" in elite rugby players with soreness present throughout the entire season. Strategies must now be implemented to deal with the physical and psychological consequences of prolonged feeling of pain.

Heading Frequency Is More Strongly Related to Cognitive Performance Than Unintentional Head Impacts in Amateur Soccer Players.

PubMed

Stewart, Walter F; Kim, Namhee; Ifrah, Chloe; Sliwinski, Martin; Zimmerman, Molly E; Kim, Mimi; Lipton, Richard B; Lipton, Michael L

2018-01-01

Compared to heading, unintentional head impacts (e.g., elbow to head, head to head, head to goalpost) in soccer are more strongly related to risk of moderate to very severe Central Nervous System (CNS) symptoms. But, most head impacts associated with CNS symptoms that occur in soccer are mild and are more strongly related to heading. We tested for a differential relation of heading and unintentional head impacts with neuropsychological (NP) test performance. Active adult amateur soccer players were recruited in New York City and the surrounding areas for this repeated measures longitudinal study of individuals who were enrolled if they had 5+ years of soccer play and were active playing soccer 6+ months/year. All participants completed a baseline validated questionnaire ("HeadCount-2w"), reporting 2-week recall of soccer activity, heading and unintentional head impacts. In addition, participants also completed NP tests of verbal learning, verbal memory, psychomotor speed, attention, and working memory. Most participants also completed one or more identical follow-up protocols (i.e., HeadCount-2w and NP tests) at 3- to 6-month intervals over a 2-year period. Repeated measures General Estimating Equations (GEE) linear models were used to determine if variation in NP tests at each visit was related to variation in either heading or unintentional head impacts in the 2-week period before testing. 308 players (78% male) completed 741 HeadCount-2w. Mean (median) heading/2-weeks was 50 (17) for men and 26 (7) for women. Heading was significantly associated with poorer performance on psychomotor speed ( p  < 0.001) and attention ( p  = 0.02) tasks and was borderline significant with poorer performance on the working memory ( p  = 0.06) task. Unintentional head impacts were not significantly associated with any NP test. Results did not differ after excluding 22 HeadCount-2w with reported concussive or borderline concussive symptoms. Poorer NP test performance was

Evaluation of the offensive behavior of elite soccer teams.

PubMed

Papadimitriou, K; Aggeloussis, N; Derri, V; Michalopoulou, M; Papas, M

2001-10-01

The purpose of the present study was to evaluate the offensive behavior of the four elite teams (France, Brazil, Croatia, and Holland) using data from the semifinals of the 18th World Soccer Championship in France in 1998. 28 videotaped soccer games were observed, 7 for each team. The protocol contained the following parameters of evaluation: (a) successful pass in the defensive and middle area, (b) unsuccessful pass in the defensive and middle area, (c) attempt on goal in the offensive area, and (d) cross and follow-up action. A multivariate analysis of variance showed the teams' plan was significantly different only in playing the ball back to the goalkeeper. This last action, used more often by Holland than by the other teams, indicated its restrained offensive behavior, which may be one of the reasons for its defeat in some games.

Impacts of Playing after School on Academic Performance: A Propensity Score Matching Approach

ERIC Educational Resources Information Center

Li, Yajuan; Palma, Marco A.; Xu, Zhicheng Phil

2017-01-01

We present a plausible causal analysis of the impact of playing after school on academic performance and investigate parental support as a potential channel. We exploit the data from the 2011 Trends in International Mathematics and Science Survey to evaluate the effects by using a propensity score matching approach. The results show that playing…

A Study of Relationships among Technical, Tactical, Physical Parameters and Final Outcomes in Elite Soccer Matches as Analyzed by a Semiautomatic Video Tracking System.

PubMed

Filetti, Cristoforo; Ruscello, Bruno; D'Ottavio, Stefano; Fanelli, Vito

2017-06-01

The performance of a soccer team depends on many factors such as decision-making, cognitive and physical skills, and dynamic ever-changing space-time interactions between teammate and opponents in relation to the ball. Seventy ( n = 70) matches of the Italian SERIE A season 2013-2014 were investigated to analyze the mean performance of 360 players in terms of physical (physical efficiency index; PEI) and technical-tactical (technical efficiency index; TEI) standpoints. Using a semiautomatic video analysis system that has incorporated new parameters able to measure technical-tactical and physical efficiency (Patent IB2010/002593, 2011-ISA), the correlation between these new variables and how much it relates to the likelihood of winning were verified. Correlations between TEI and PEI were significant ( n = 140, r = .60, p < .001), and TEI showed a higher likelihood of winning than PEI factors ( p < .0001 vs. .0001, CI 95% [1.64, 3.00] vs. [1.28, 2.07]). Higher TEI and TEI + PEI differences between the teams were associated with a greater likelihood of winning, but PEI differences were not. Key performance indicators and this performance assessment method might be useful to better understand what determines winning and to assist the overall training process and match management.

Time - motion analysis of professional rugby union players during match-play.

PubMed

Deutsch, M U; Kearney, G A; Rehrer, N J

2007-02-15

The aim of this study was to quantify the movement patterns of various playing positions during professional rugby union match-play, such that the relative importance of aerobic and anaerobic energy pathways to performance could be estimated. Video analysis was conducted of individual players (n=29) from the Otago Highlanders during six "Super 12" representative fixtures. Each movement was coded as one of six speeds of locomotion (standing still, walking, jogging, cruising, sprinting, and utility), three states of non-running intensive exertion (rucking/mauling, tackling, and scrummaging), and three discrete activities (kicking, jumping, passing). The results indicated significant demands on all energy systems in all playing positions, yet implied a greater reliance on anaerobic glycolytic metabolism in forwards, due primarily to their regular involvement in non-running intense activities such as rucking, mauling, scrummaging, and tackling. Positional group comparisons indicated that while the greatest differences existed between forwards and backs, each positional group had its own unique demands. Front row forwards were mostly involved in activities involving gaining/retaining possession, back row forwards tended to play more of a pseudo back-line role, performing less rucking/mauling than front row forwards, yet being more involved in aspects of broken play such as sprinting and tackling. While outside backs tended to specialize in the running aspects of play, inside backs tended to show greater involvement in confrontational aspects of play such as rucking/mauling and tackling. These results suggest that rugby training and fitness testing should be tailored specifically to positional groups rather than simply differentiating between forwards and backs.

Soccer-Specific Warm-Up and Lower Extremity Injury Rates in Collegiate Male Soccer Players

PubMed Central

Grooms, Dustin R.; Palmer, Thomas; Onate, James A.; Myer, Gregory D.; Grindstaff, Terry

2013-01-01

Context: A number of comprehensive injury-prevention programs have demonstrated injury risk-reduction effects but have had limited adoption across athletic settings. This may be due to program noncompliance, minimal exercise supervision, lack of exercise progression, and sport specificity. A soccer-specific program described as the F-MARC 11+ was developed by an expert group in association with the Federation Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) to require minimal equipment and implementation as part of regular soccer training. The F-MARC 11+ has been shown to reduce injury risk in youth female soccer players but has not been evaluated in an American male collegiate population. Objective: To investigate the effects of a soccer-specific warm-up program (F-MARC 11+) on lower extremity injury incidence in male collegiate soccer players. Design: Cohort study. Setting: One American collegiate soccer team followed for 2 seasons. Patients or Other Participants: Forty-one male collegiate athletes aged 18–25 years. Intervention(s): The F-MARC 11+ program is a comprehensive warm-up program targeting muscular strength, body kinesthetic awareness, and neuromuscular control during static and dynamic movements. Training sessions and program progression were monitored by a certified athletic trainer. Main Outcome Measure(s): Lower extremity injury risk and time lost to lower extremity injury. Results: The injury rate in the referent season was 8.1 injuries per 1000 exposures with 291 days lost and 2.2 injuries per 1000 exposures and 52 days lost in the intervention season. The intervention season had reductions in the relative risk (RR) of lower extremity injury of 72% (RR = 0.28, 95% confidence interval = 0.09, 0.85) and time lost to lower extremity injury (P < .01). Conclusions: This F-MARC 11+ program reduced overall risk and severity of lower extremity injury compared with controls in collegiate-aged male soccer

An investigation of the practice activities and coaching behaviors of professional top-level youth soccer coaches.

PubMed

Partington, M; Cushion, C

2013-06-01

The aim of this study was to investigate the coaching behaviors of elite English youth soccer coaches in different practice settings and gain insight into the coaches' cognitive processes underpinning these behaviors. The practice setting was split into two types of activities, "training form" and "playing form," and behavioral data were collected using a modified version of the Coach Analysis and Intervention System. Interpretive interview data were triangulated with the behavioral data to ensure that both the "what" and the "why" of the coaches' behavior and practice were considered. The results showed the coaches using more "training form" activities than "playing form," and using high levels of prescriptive instruction, regardless of practice type, in contrast to a stated desire to "developing the whole player," creating "decision makers," and being a "facilitator of knowledge creation." The interviews revealed that the coaches had a low self-awareness about their behavior, with an epistemological gap identified between understanding and practice, with statements of intent not being matched by knowledge and action. © 2011 John Wiley & Sons A/S.