Half Of Match Research Articles

Sprinting Activities and Distance Covered by Top Level Europa League Soccer Players

This study presents a detailed analysis of sprinting activities and distance covered by professional soccer players in two seasons of the Europa League competition. The investigation considered such variables as the mean sprinting distance covered, duration of the rest pause between sprinting activities and maximal running speed recorded during the match. The study involved 147 soccer players participating in 10 matches played at one ground in the 2008–2009 and 2010–2011 Europa League seasons. Players' performance data were divided into two halves of matches and five playing positions. The study was carried out using data from Amisco Pro (version 1.0.2.). Results indicate wide variations in the analyzed variables, depending on the playing position on the pitch and tactical tasks. Individualization of training speed and endurance loads will help to optimize the training process of soccer players at different levels of their athletic skills.

Association between playing tactics and creating scoring opportunities in elite football. A case study in Spanish Football National Team

The aim of this study was to examine the association between playing tactics, situational variables and creating scoring opportunities according to the type of start-up possession in a case-study. All team possessions (n=857) developed by the Spanish Football national team during the World Cup 2010 were analysed and grouped into “strategic set-plays” (n=90), “recoveries” (n=451) and “restarts” (n=316). Fourteen categorical variables which describe offensive playing tactics, opponent situation as well as situational variables and their associations with creating scoring opportunities were examined using chi-square analysis and bivariate logistic regressions. Chi-square analysis showed that “strategic set-plays” were more effective to produce scoring opportunities (29.2%) than recoveries (15.4%) and restarts (8.9%) ( P <0.001). Within the strategic set-plays, no differences were found between corners kicks and free kicks to produce scoring opportunities. In recoveries, the variables “field starting zone” ( P =0.001), “initial penetration” ( P <0.001), “initial opponent number” ( P =0.004), “initial opponent position” ( P =0.014), “initial penetration zone” ( P <0.001), and “type of progression” ( P =0.049), and for restarts “pass number” ( P =0.049) and “duration” ( P =0.006) were associated with the likelihood of creating scoring opportunities. More scoring opportunities were created in the second half ( P= 0.022). The type of start-up possession and the match half may modify the playing tactics developed during the offensive process and influence the creation of scoring opportunities in Football.

Activity Profile of International Rugby Sevens: Effect of Score Line, Opponent, and Substitutes.

To investigate the influence of score line, level of opposition, and timing of substitutes on the activity profile of rugby sevens players and describe peak periods of activity. Velocity and distance data were measured via 10-Hz GPS from 17 international-level male rugby sevens players on 2-20 occasions over 4 tournaments (24 matches). Movement data were reported as total distance (TD), high-speed-running distance (HSR, 4.17-10.0 m/s), and the occurrence of maximal accelerations (Accel, ≥2.78 m/s2). A rolling 1-min sample period was used. Regardless of score line or opponent ranking there was a moderate to large reduction in average and peak TD and HSR between match halves. A close halftime score line was associated with a greater HSR distance in the 1st minute of the 1st and 2nd halves compared with when winning. When playing against higher- compared with lower-ranked opposition, players covered moderately greater TD in the 1st minute of the 1st half (difference = 26%; 90% confidence limits = 6, 49). Compared with players who played a full match, substitutes who came on late in the 2nd half had a higher average HSR and Accel by a small magnitude (31%; 5, 65 vs 34%; 6, 69) and a higher average TD by a moderate magnitude (16%; 5, 28). Match score line, opposition, and substitute timing can influence the activity profile of rugby sevens players. Players are likely to perform more running against higher opponents and when the score line is close. This information may influence team selection.

Match analysis in football: a systematic review

The main focus of this paper was to review the available literature on match analysis in adult male football. The most common research topics were identified, their methodologies described and the evolutionary tendencies of this research area systematised. A systematic review of Institute for Scientific Information (ISI) Web of Knowledge database was performed according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) guidelines. The following keywords were used: football and soccer, each one associated with the terms: match analysis, performance analysis, notational analysis, game analysis, tactical analysis and patterns of play. Of 2732 studies initially identified, only 53 were fully reviewed, and their outcome measures abstracted and analysed. Studies that fit all inclusion criteria were organised according to their research design as descriptive, comparative or predictive. Results showed that 10 studies focused predominantly on a description of technical, tactical and physical performance variables. From all comparative studies, the dependent variables more frequently used were “playing position” and “competitive level”. Even though the literature stresses the importance of developing predictive models of sports performance, only few studies (n = 8) have focused on modelling football performance. Situational variables like game location, quality of opposing teams, match status and match half have been progressively included as object of research, since they seem to work as effective covariables of football performance. Taking into account the limitations of the reviewed studies, future research should provide comprehensive operational definitions for the studied variables, use standardised categories and description of activities and participants, and consider integrating the situational and interactional contexts into the analysis of football performance.

THE EFFECT OF LOCALISED AND GLOBALISED FATIGUE ON MUSCLE LATENCY IN HEALTHY AND FUNCTIONALLY UNSTABLE PARTICIPANTS FOLLOWING A SIMULATED ANKLE SPRAIN

BackgroundAnecdotally, most injuries occur during the final third of the second half of a soccer match when fatigue is present. To our knowledge, no studies have evaluated muscular latency times...

Movement Demands of Elite Rugby League Players during Australian National Rugby League and European Super League Matches

This study compared the movement demands of players competing in matches from the elite Australian and European rugby league competitions. Global positioning system devices were used to measure 192 performances of forwards, adjustables, and outside backs during National Rugby League (NRL; n = 88) and European Super League (SL; n = 104) matches. Total and relative distances covered overall and at low (0-3.5 m/s), moderate (3.6-5 m/s), and high (>5 m/s) speeds were measured alongside changes in movement variables across the early, middle, and late phases of the season. The relative distance covered in SL matches (95.8 ± 18.6 m/min) was significantly greater (P < .05) than in NRL matches (90.2 ± 8.3 m/min). Relative low-speed activity (70.3 ± 4.9 m/min vs 75.5 ± 18.9 m/min) and moderate-speed running (12.5 ± 3.3 m m/min vs 14.2 ± 3.8 m/min) were highest (P < .05) in the SL matches, and relative high-speed distance was greater (P < .05) during NRL matches (7.8 ± 2.1 m/min vs 6.1 ± 1.7 m/min). NRL players have better maintenance of high-speed running between the first and second halves of matches and perform less low- and moderate-speed activity, indicating that the NRL provides a higher standard of rugby league competition than the SL.

Measuring Collective Behaviour in Football Teams: Inspecting the impact of each half of the match on ball possession

The aim of this study was to inspect the influence of each half of match and the ball possession status on the players’ spatio-temporal relationships. Three official matches of a professional football team were analysed. From the players’ locations were collected the team’s wcentroid, wstretch index, surface area and effective area of play at 9218 play instants. The results suggested that the values of teams’ dispersion and average position on the field decreases during the 2nd half of the match. In sum, this study showed that the half of match and the ball possession status influenced players’ spatio-temporal relationships, in a way that significantly contributes to the collective understanding of football teams.

Match running performance fluctuations in elite soccer: Indicative of fatigue, pacing or situational influences?

The aims of this study were to: (1) quantify match running performance in 5-min periods to determine if players fatigue or modulate high-intensity running according to a pacing strategy, and (2) examine factors impacting high-intensity running such as score line, match importance and the introduction of substitutes. All players were analysed using a computerised tracking system. Maintaining ‘high’ levels of activity in the first half resulted in a 12% reduction (P < 0.01) in the second half for high-intensity running (effect size [ES]: 0.8), while no changes were observed in ‘moderate’ and ‘low’ groups (ES: 0.0–0.2). The ‘high’ group covered less (P < 0.01) high-intensity running in the initial 10-min of the second versus first half (ES: 0.6–0.7), but this was not observed in ‘moderate’ and ‘low’ groups (ES: 0.2–0.4). After the most intense periods, players demonstrated an 8% drop in high-intensity running (P < 0.05) compared to the match average (ES: 0.2) and this persisted for 5-min before recovering. Players covered similar high-intensity running distances in matches with differing score lines but position-specific trends indicated central defenders covered 17% less (P < 0.01) and attackers 15% more high-intensity running during matches that were heavily won versus lost (ES: 0.9). High-intensity running distances were comparable in matches of differing importance, but between-half trends indicated that only declines (P < 0.01) occurred in the second half of critical matches (ES: 0.2). Substitutes covered 15% more (P < 0.01) high-intensity running versus the same time period when completing a full match (ES: 0.5). The data demonstrate that high-intensity running in the second half is impacted by the activity of the first half and is reduced for 5-min after intense periods. High-intensity running is also influenced by score line and substitutions but not match importance. More research is warranted to establish if fluctuations in match running performance are primarily a consequence of fatigue, pacing or tactical and situational influences.

Comparisons of RNA-seq results for cryopreserved (CRYO) and formalin fixed, paraffin-embedded (FFPE) samples.

e22211 Background: FFPE is the worldwide clinical standard for preservation of tissue samples. Although CRYO tissues are widely used for research, most gene expression assays in clinical use analyze FFPE by RT-PCR. Use of RT-PCR limits numbers of transcripts that can be studied with material available. Next Generation Sequencing promises to overcome those limitations, but for FFPE, there are concerns related to its accuracy including bias associated with RNA truncated at the 3’ end. Little data is available illustrating the extent of truncation or considering implications for bioinformatics analysis of sequencing results. Methods: Total RNA was extracted from patient consented specimens of tumor and normal bladder tissue split with matching halves processed by CRYO and FFPE. Paired end sequencing libraries 100 bp in length were generated using Illumina TruSeq RNA sample kits with minor modifications for FFPE samples. Sequencing was performed on the Illumina HiSeq 2000, aligned with TopHat using the hg19 reference sequence, and further analyzed using open source bioinformatics tools. Results: Comparing Cryo and FFPE reads for a representative specimen, the proportion of reads that mapped to the reference genome were 69% and 63% for normal, and 66% and 63% for tumor specimens. Mapped reads yielded over 25,000 significantly expressed transcripts, isoforms, and splice variants. The extent of 3’ bias was investigated by viewing data in the Integrated Genome Viewer and using Picard tools. Preliminary estimates of 3’ bias in FFPE showed 2.22 for normal and 1.48 for tumor. After accounting for bias, transcripts in CRYO vs FFPE were significantly correlated for both normal tissue and tumor (R2 = 0.76 and 0.95, respectively). Mutations previously identified in these samples by SureSelect hybrid capture system (Agilent) were also observed in the RNA-seq data. Conclusions: FFPE samples can be successfully analyzed by RNA-Seq, allowing the analysis of standard clinical samples and vast quantities of richly annotated archival specimens. Results from CRYO and FFPE analyses are similar when performed using minor modifications to sequencing library preparation and careful attention to appropriate analysis.

Half-Time and High-Speed Running in the Second Half of Soccer

This study investigated if the quantity of high-speed running (movements >15 km.h(-1) completed in the first 15 min of competitive football matches differed from that completed in the corresponding 15 min of the second half. 20 semi-professional soccer players (age 21.2±3.6 years, body mass 76.4±3.8 kg, height 1.89±0.05 m) participated in the study. 50 competitive soccer matches and 192 data files were analysed (4±2 files per match) using Global Positioning Satellite technology. Data were analysed using 2-way repeated measures ANOVA and Pearson correlations. No differences were found between the first 15 min of each half for the distance completed at high-speed (>15 km.h(-1) or sprinting (>21 km.h(-1), or in the number of sprints undertaken (p>0.05). However, total distance covered was shorter (1st half vs. 2nd half: 1746±220 vs. 1644±224 m; p<0.001) and mean speed lower (1st half vs. 2nd half: 7.0±0.9 vs. 6.6±0.9 km.h(-1); p<0.001) in the first 15 min of the second half compared to the first. The correlations between the duration of the half-time interval and the difference in the high-speed running or sprinting between first and second halves (0-15 min) were very small (r=0.08 [p=0.25] and r=0.04 [p=0.61] respectively). Therefore, this study did not find any difference between the amount of high-speed running and sprinting completed by semi-professional soccer players when the first 15 min of the first and second half of competitive matches were compared The maintenance of high-speed running and sprinting, as total distance and mean speed declined, may be a function of the pacing strategies adopted by players in competitive matches.

Repeated High-Intensity Running and Sprinting in Elite Women’s Soccer Competition

To the authors' knowledge, no study has investigated the concurrent repeated, high-intensity (RHIA) and repeated-sprint activity (RSA) of intermittent team-sport competition. In this study, they report on the RSA of elite women's football competition. In addition, they describe the nature of RHIA (eg, striding and sprinting activities) that involve a high energy cost and are associated with short (ie, ≤20 s) recovery periods. Thirteen elite women soccer players underwent video-based time-motion analysis on 34 occasions during national and international standard matches. RSA and RHIA were defined as successive (ie, 2) sprints or striding and sprinting efforts that occurred with ≤20 s between efforts. The number of RSA and RHIA bouts performed was similar between the first and second halves of matches. Sprinting and striding/sprinting durations tended to remain relatively stable irrespective of the number of efforts in an RSA or RHIA bout or the period of play. However, recovery duration between efforts increased in the second half, when a greater number of efforts were performed per bout. These findings suggest that first- to second-half reductions in RHIA and RSA do not occur in elite women's soccer competition. However, players increase the amount of low-intensity recovery undertaken between RHIA and RSA efforts, most likely in an attempt to maintain RHIA and RSA performance. These findings emphasize the importance of RSA and RHIA to elite women's soccer and highlight the importance of training this quality to prevent reductions in performance during competitive match play.

Current Match-Analysis Techniques’ Underestimation of Intense Periods of High-Velocity Running

To compare the peak 5-min period of high-velocity running (HiVR) during a soccer match using a predefined vs a rolling time interval. Player movement data were collected from 19 elite Australian soccer players over 11 competitive matches (77 individual match files) using a 5-Hz global-positioning system. Raw velocity data were analyzed to determine the period containing the greatest HiVR distance per match half and the distance covered in the subsequent epoch. Intervals were identified using either a predefined (distance covered in 5 min at every 5-min time point) or rolling (distance covered in 5 min from every time point) method. The percentage difference ± 90% confidence limits were used to determine differences between methods. Predefined periods underestimated peak distance covered by up to 25% and overestimated the subsequent epoch by up to 31% compared with rolling periods. When the distance decrement between the peak and following period was determined, there was up to a 52% greater reduction in running performance using rolling periods than predefined ones. It is recommended that researchers use rolling as opposed to predefined periods when determining specific match intervals because they provide a more accurate representation of the HiVR distance covered. This will avoid underestimation of both match running distance and the decrement in running performance after an intense period of play. This may have practical implications for not only researchers but also staff involved in a club setting who use this reduction as evidence of transient fatigue during a match.

O efeito das substituições realizadas no segundo tempo da partida na intensidade de jogo de futebol. DOI:10.5007/1980-0037.2012v14n2p183

Most soccer matches are conducted by coaches who usually make all player substitutions allowed. Therefore, it is extremely important to study these substitutions and their effects on the intensity of effort required from players. To date, no published studies have reported on this topic using heart rate (HR) as an intensity parameter. The objective of this study was to compare effort intensity (EI) of soccer players in the following situations: 1) first half (FH-EI); 2) second half (SH-EI); 3) second half with substitutions(SHS-EI). Forty-five male soccer players (18.5±1.2 years old, 74.25±5.79 kg, 182.6±8.55 cm, 9.56±2.47% body fat, 56.3±4.3 mLO2/kg/min) were evaluated during 29 official games. EI was considered as the mean HR, expressed as the percentage of each player’s maximal HR (%HRmax) and as the time spent in each intensity zone (Z) according to %HRmax (Z1&lt;70%; Z2 70-85%; Z3 85-90%; Z4 90-95%; Z5 95-100%). FH-EI (86.3±3.3%HRmax) was higher than SH-EI (80.6±4.4%HRmax) and SHS-EI (83.6±2.8%HRmax). SHS-EI was higher than SH-EI (p&lt;0.05). Time spent in high-intensity zones was lower in SH-EI than in FH-EI, buthigher in SHS-EI when compared to SH-EI (p&lt;0.05). It was concluded that the decrease in EI in the second half of soccer matches was attenuated by substitutions made at halftime, as evidenced by a longer time spent in high-intensity zones when compared to SH-EI.

The effects of one-half of a soccer match on the postural stability and functional capacity of the lower limbs in young soccer players

OBJECTIVE:Most injuries occur during the final 15 minutes of each half of a soccer match, suggesting that physical exertion may influence changes in neuromuscular control and the body's ability to stabilize the joints of the lower extremities. The aim of this study was to analyze the effects of one-half of a soccer match on the functional capacity and stability of the lower limbs in young soccer players.METHODS:We analyzed 27 soccer players by evaluating the functional capacity of their lower limbs using the hop test protocol and their level of postural stability using the Biodex Stability System. The evaluations were performed before and after 45 minutes of game time.RESULTS:After the match, there was a decrease in the overall stability index (OSI) (F(1,23) = 5.64, p = 0.026) and the anterior-posterior stability index (APSI) (F(1,23) = 5.24,p = 0.032). In the single and triple hop tests, there was a higher functional capacity in the dominant limb compared to the non-dominant limb in the pre- and post-game comparisons.CONCLUSION:The results of this study show that there is a decrease in the stability of the lower limbs in young soccer players after a 45 minutes soccer match, but the same result was not found for the functional capacity.

Are Physical Performance and Injury Risk in a Professional Soccer Team in Match-Play Affected Over a Prolonged Period of Fixture Congestion?

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 that covered at lower intensities varied across games, high-intensity running performance and injury risk were generally unaffected during a prolonged period of fixture congestion. These results might be linked to squad rotation and post-match recovery strategies in place at the present club.

Contextual Variables and Time-Motion Analysis in Soccer

Using a multi-camera computerised tracking system the present study aimed to provide a detailed analysis of the work-rate profile of a team of elite soccer players during official matches of the Spanish Premier League. Observation-based performance measures were obtained from 434 individual samples. 6 physical parameters involving the distance covered by players were analysed: standing intensity (0-11 km·h (-1)), low-intensity running (11.1-14 km·h (-1)), moderate-intensity running (14.1-17 km·h (-1)), high-intensity running (17.1-21 km·h (-1)), very high-intensity running (21.1-24 km·h (-1)) and sprinting (>24 km·h (-1)). These intensity thresholds were considered with respect to 4 contextual variables: MATCH STATUS, MATCH LOCATION, OPPONENT LEVEL and MATCH HALF, which were analysed in relation to the EFFECTIVE PLAYING TIME. A descriptive analysis and a multivariate mixed model were employed for the analysis of change processes in soccer. The distance total covered (m) by players at different work intensities during the EFFECTIVE PLAYING TIME was greater when playing at HOME (3 931 vs. 3 887 AWAY), when the reference team was LOSING (3 975 vs. 3 837 DRAWING and 3 921 WINNING) and when the level of the opposing team was HIGHER (4 032 vs. 3 938 MEDIUM and 3 736 BOTTOM). By contrast, their physical performance decreased during the 2NDHALF of matches (3 822 vs. 3 985 1ST HALF).

The Effect of a Cold Environment on Physical Activity Profiles in Elite Soccer Match-Play

In this study, the effect of cold temperature on the physical activity profiles of professional soccer players in official match-play was investigated. Computerised motion-analysis was used to analyse performance in 9 players (4 defenders and 5 midfielders) in 4 temperature ranges: ≤ 5°C (29 matches), 6-10°C (62 matches), 11-20°C (48 matches) and ≥ 21°C (27 matches). Performance was analysed per minute for total distance covered and distance run in 3 categories: 0.0-14.3 km/h (walking/low/moderate); 14.4-19.7 km/h (running); ≥ 19.8 km/h (high-intensity). Results showed that while total distance run per minute was unaffected in colder conditions, midfielders ran significantly shorter distances in warmer temperatures: ≥21°C = 118.7 ± 6.9 m vs. ≤ 5°C=124.2 ± 7.1 m, p < 0.01; 6-10°C = 123.6 ± 6.8 m, p < 0.01; and, 11-20°C = 123.4 ± 5.4, p < 0.05). The total distance covered at 3 intensities and across halves was unaffected by temperature. Similarly, high-intensity efforts across match halves and in the first and final 5-min periods in each half of normal time were unaffected by temperature. In contrast, high-intensity efforts in midfielders across 15-min intervals were affected by temperature with greater distances covered per minute in the 30-45 min period in matches played in temperatures ≤ 5°C vs. the corresponding period in those played in temperatures ≥ 21°C (9.1 ± 3.8 m vs. 6.2 ± 3.0 m, p < 0.05). The present findings generally suggest that physical performance in professional soccer does not decrease in cold temperatures.

Video analysis of tackles in professional rugby league matches by player position, tackle height and tackle location

This paper describes the nature, height, site and direction of tackles seen in professional rugby league. Retrospective observational analysis was conducted using videos of 80 rugby league matches from 2008. There were 50,019 tackles recorded representing 701 ±64 tackles per match. Nearly 50% of tackles involved tacklers from behind the visual fields of the ball carrier, most tackles involved either two or three tacklers and most tackles involved contact with the mid-torso and hip-thigh region of the ball carrier. Significantly more players were involved in the tackle in the first, than the second half of matches (χ2=4.3, df=1, p=0.038). Significantly more tackles were recorded in the defence than the attack side of the field. Forwards were more commonly involved in the tackle than backs. Forwards were significantly more involved in tackle events than backs but when viewed in player groups, adjustables were involved in significantly more tackle events than outside backs and hit-up forwards. Coaches should focus on getting players to practice correct tackle technique during tackling with two or more players involved in the tackle and especially, when making a tackle in the ball carriers blind vision area.

Ball-Sport Endurance and Sprint Test (BEAST90): Validity and Reliability of a 90-Minute Soccer Performance Test

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.

Injury incidence and injury patterns in professional football: the UEFA injury study

ObjectiveTo study the injury characteristics in professional football and to follow the variation of injury incidence during a match, during a season and over consecutive seasons.DesignProspective cohort study where teams...