Recovery time variation during sprint interval training impacts amateur soccer players adaptations - a pilot study.

The objective of the present study was to investigate the selected performance adaptations of amateur soccer players to 2 different running-based sprint interval training (SIT) protocols with different recovery intervals and work-rest ratios (1:5 & 1:1). Twenty-three subjects (age 21.4 ± 1.1 years; height 175.4 ± 4.7 cm; body mass 69 ± 6.4 kg) participated in the study. Before the 6-weeks training period, participants completed 3-weeks of low-intensity training preparation. Subsequently, the pre-tests (anthropometric measurements, repeated sprint test [12 × 20-m with 30-s recovery intervals], Yo-YoIRT1 & Yo-YoIRT2 and treadmill VO2max test) were conducted. Thereafter, participants were randomly divided into 3 sub-groups (1 - SIT with 150 s recovery intervals [SIT150, n = 8]; 2 - SIT with 30 s recovery intervals [SIT30, n = 7]; and 3 - control group [CG, n = 8]). SIT150 and SIT30 training groups completed sprint interval training (2-days/week; 30-s all-out running, 6-10 repetition with 150 s recovery intervals for SIT150 and 30 s for SIT30 groups, respectively), a soccer match (1-day) and routine soccer training (3-days) per week. The CG attended only routine training sessions and the soccer-match (4-days). The study experiments and the trainings were conducted during off-season. Yo-YoIRT1, Yo-YoIRT2, and VO2max were significantly improved both in SIT30 and SIT150 (p < 0.05) groups. Yo-YoIRT1 and VO2max were also significantly improved in CG (p < 0.05). Both the SIT150 and SIT30 training were shown to improve Yo-YoIRT1, Yo-YoIRT2 and VO2max performance compared to the control group, nevertheless, SIT150 was more efficient in improving the Yo-YoIRT1, Yo-YoIRT2 than SIT30. The authors of this study suggest using SIT150 to induce more effective performance outputs in amateur soccer players.

Effects of congested match periods on acceleration and deceleration profiles in professional soccer.

The aim of the present study was to analyse the influence of congested periods of matches on the acceleration (Acc) and deceleration (Dec) profiles of elite soccer players. Twenty-three elite male professional soccer players participated in the study across 31 official matches. Assessed periods included: (i) congested periods (three to four days between games), and (ii) non-congested periods (more than four days between games). Physical activity during matches was recorded during games using a 10Hz global positioning system device, coupled with a 100 Hz accelerometer, and was analysed according to the periods. Maximal Acc- (73.2 ± 20.3 vs. 84.918.5 m), high Acc- (244.0 ± 49.5 vs. 267.0 ± 37.8 m), maximal Dec- (139.0 ± 44.8 vs. 152.039.3 m) and the total decelerating- distance (5132 ± 690 vs. 5245 ± 552 m) were lower in congested than in non-congested periods (p < 0.05, effect size 0.31-0.70). Neither a main effect of playing position nor a period*playing position interaction on Acc and Dec were observed (p > 0.05). It was concluded that Acc and Dec match activities were significantly affected during congested periods compared to non-congested highlighting a possible fatigue accumulation being responsible for the observed decrement in physical activity. Monitoring Acc and Dec metrics throughout particular periods of congested fixtures amongst professional soccer teams is advised and may be a way to assess physical and fatigue status.

Acute effects of small-sided games combined with running drills on internal and external loads in young soccer players.

The purpose of this study was to compare the effects of regular small-sided games (SSGreg) and SSGs combined with running drills (SSGcom) on players' internal and external loads. Eighteen young male soccer players (average age: 18.2 ± 0.5 years) participated in 3 vs. 3 and 4 vs. 4 games, under both SSGreg and SSGcom conditions. SSGreg bouts were played for 4 minutes without additional running drills, while SSGcom bouts consisted of 3 min 30 s SSG and 15 s running before and after the bout, making the duration of each bout 4 minutes. During all SSGs, measurements of heart rate (HR) responses as well as distances covered in four different speed zones - walking (WLK), low-intensity (LIR), moderate-intensity (MIR) and high-intensity running (HIR) - were recorded. Technical characteristics were monitored during the SSGs, and the rating of perceived exertion (RPE) and blood lactate (La-) responses were determined at the end of each SSG condition. Compared to the SSGreg in both 3 vs. 3 and 4 vs. 4 formats, the SSGcom condition resulted in higher La- and RPE responses (p < 0.05), greater distance covered at MIR and HIR speeds and greater total distance (p < 0.05). The results of this study show that replacing 30 s within the 4-min bouts of SSGs (both 3- and 4-a-side) by 2 x 15 s of running drills is effective in increasing internal (La- and RPE) and external loads (MIR and HIR) without a significant decrease in total passes and successful passes in young soccer players.

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

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.

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

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.

Do cognitive training strategies improve motor and positive psychological skills development in soccer players? Insights from a systematic review.

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.

High-Intensity Training and Salivary Immunoglobulin A Responses in Professional Top-Level Soccer Players: Effect of Training Intensity.

Owen, AL, Wong, DP, Dunlop, G, Groussard, C, Kebsi, W, Dellal, A, Morgans, R, and Zouhal, H. High-intensity training and salivary immunoglobulin A responses in professional top-level soccer players: Effect of training intensity. J Strength Cond Res 30(9): 2460-2469, 2016-This study aimed (a) to test the hypothesis that salivary immunoglobulin A (s-IgA) would vary with training intensity sessions (low-intensity [LI] vs. high-intensity sessions [HI]) during a traditional training program divided into 4 training periods and (b) to identify key variables (e.g., GPS data, rating of perceived exertion [RPE], and training duration), which could affect s-IgA. Saliva samples of 10 elite professional soccer players were collected (a) before the investigation started to establish the baseline level and (b) before and after each 4 training sessions (LI vs. HI). Training intensity was monitored as internal (through heart rate responses and RPE) and external (through GPS) loads. High-intensity sessions were associated with higher external load (GPS) and with higher RPE. Baseline and pretraining s-IgA did not differ between the 4 training sessions both for HI and LI. Post-training s-IgA were not different (in absolute value and in percentage of change) between HI and LI sessions at the first 3 periods. However, at the fourth period, s-IgA concentration for HI session was significantly lower (p ≤ 0.05) than the LI session. The percentage change between s-IgA post-training and s-IgA baseline concentrations differ significantly (p ≤ 0.05) between HI and LI training sessions. Significant correlations between s-IgA and training intensity were also noted. High-intensity soccer training sessions might cause a significant decrease in s-IgA values during the postexercise window as compared with LI sessions. This study encourages coaches to monitor s-IgA in routine, particularly during HI training periods, to take precautions to avoid upper respiratory tract infection in highly trained soccer players.

Changes of the psychophysical state and feeling of wellness of professional soccer players during pre-season and in-season periods.

Perceived changes due to training monotony, strain, sleep, stress, fatigue, muscle soreness and the influence of specific training sessions on the affective valence were explored in professional soccer players. Seventeen players completed the Hooper questionnaire, the ratings of perceived exertion and feeling scale (FS) every training/match day before and during the soccer season. Higher players' training loads were recorded during pre-season when compared with in-season period (2558.1 ± 262.4 vs. 1642.8 ± 169.3 a.u., p < 0.01; respectively). The ratings of sleep, stress, fatigue and muscle soreness in pre-season were higher than those observed during in-season (p < 0.01) whereas the feeling score was lower (p < 0.01). Furthermore, training sessions, including technical/tactical work, induced an improved feeling score but linked with a lower training load when compared with sessions focus on physical emphasis (p < 0.01). Pre-season period of training induces a significantly more strenuous and exhausting demands on professional soccer players compared with the in-season period at the elite level.

The effects of a congested fixture period on physical performance, technical activity and injury rate during matches in a professional soccer team.

BACKGROUND: In modern professional soccer, the ability to recover from official match-play and intense training is often considered a determining factor in subsequent performance. OBJECTIVE: To investigate the influence of playing multiple games with a short recovery time between matches on physical activity, technical performance and injury rates. METHODS: The variation of physical (overall distance, light-intensity, low-intensity, moderate-intensity and high-intensity running) and technical performance (successful passes, balls lost, number of touches per possession and duels won) of 16 international players was examined during three different congested periods of matches (six games in 18 days) from the French League and Cup (n=12), and the UEFA Champions' League (n=6) during the 2011-2012 season and compared with that reported in matches outside these periods. Data were collected using a computerised match analysis system (Amisco). Injury rate, time loss injuries, as well as the mechanism, circumstances and severity of the injury were also analysed. RESULTS: No differences were found across the six successive games in the congested period, and between no congested and the three congested periods for all the physical and technical activities. The total incidence of injury (matches and training) across the prolonged congested periods did not differ significantly to that reported in the non-congested periods. However, the injury rate during match-play was significantly higher during the congested period compared with the non-congested period (p<0.001). The injury rate during training time was significantly lower during the congested period compared with the non-congested periods (p<0.001). The mean lay-off duration for injuries was shorter during the congested periods compared with the non-congested periods (9.5±8.8 days vs 17.5±29.6 days, respectively p=0.012, effect sizes=0.5). CONCLUSIONS: Although physical activity, technical performance and injury incidence were unaffected during a prolonged period of fixture congestion, injury rates during training and match-play and the lay-off duration were different to that reported in matches outside this period.

Heart rate-based training intensity and its impact on injury incidence among elite-level professional soccer players.

Elite-level professional soccer players are suggested to have increased physical, technical, tactical, and psychological capabilities when compared with their subelite counterparts. Ensuring these players remain at the elite level generally involves training many different bodily systems to a high intensity or level within a short duration. This study aimed to examine whether an increase in training volume at high-intensity levels was related to injury incidence, or increased the odds of sustaining an injury. Training intensity was monitored through time spent in high-intensity (T-HI) and very high-intensity (T-VHI) zones of 85-<90% and ≥90% of maximal heart rate (HRmax), and all injuries were recorded over 2 consecutive seasons. Twenty-three, elite professional male soccer players (mean ± SD age, 25.6 ± 4.6 years; stature, 181.8 ± 6.8 cm; and body mass, 79.3 ± 8.1 kg) were studied throughout the 2-years span of the investigation. The results showed a mean total injury incidence of 18.8 (95% confidence interval [CI], 14.7-22.9) injuries per 1,000 hours of exposure. Significant correlations were found between training volume at T-HI and injury incidence (r = 0.57, p = 0.005). Further analysis revealed how players achieving more time in the T-VHI zone during training increased the odds of sustaining a match injury (odds ratio = 1.87; 95% CI, 1.12-3.12, p = 0.02) but did not increase the odds of sustaining a training injury. Reducing the number of competitive match injuries among elite-level professional players may be possible if greater focus is placed on the training intensity and volume over a period of time ensuring the potential reduction of fatigue or overuse injuries. In addition, it is important to understand the optimal training load at which adaptation occurs without raising the risk of injury.

Physiological responses according to rules changes during 3 vs. 3 small-sided games in youth soccer players: stop-ball vs. small-goals rules.

Small-sided games (SSGs) are effective for soccer-specific aerobic endurance training. To date, no study has investigated the effect of stop-ball (SB-SSG) rule on the physiological responses to SSG. Therefore, the purpose of the present study was to examine the effects of SB-SSG vs. small-goals (SG-SSG) rules on physiological responses during a 3 vs. 3 SSG in young soccer players. Twelve male amateur young soccer players (age, 14.0 ± 0.7 years; body mass, 51.8 ± 8.0 kg; height, 164 ± 7 cm) randomly performed either SB-SSG or SG-SSG for 4 × 4 min separated by 2 min of recovery on a 20 × 15 m pitch. During the SB-SSG, participants were instructed to stop the ball with the soles of their boots in a 15 × 1 m surface behind the pitch bottom line; whereas during the SG-SSG, the participants were instructed to score to a mini-goal (i.e., 1 × 0.5 m). During each test session, the mean heart rate (HR), the post-SSG rating of perceived exertion (RPE) scores and blood lactate concentrations ([La(-)]) were recorded. Results showed that SB-SSG induced significantly higher mean HR (178 ± 3 vs. 174 ± 3 bpm; P < 0.05) and [La(-)] (4.66 ± 0.98 vs. 4.16 ± 1.02 mol · L(-1); P < 0.05) than SG-SSG. However, there was no significant difference between SB-SSG and SG-SSG for the RPE scores. In conclusion, the present study demonstrates the effectiveness of SB-SSG in SSG training. Indeed, SB-SSG can influence the effort intensity in SSG (i.e., resulted in a higher intensity than SG-SSG). Therefore, coaches have the possibility to choose between SB-SSG and SG-SSG rules during training sessions according to their physical and technical objectives.

Influence of game format and number of players on heart rate responses and physical demands in small-sided soccer games.

The aim of the study was to examine the extent to which changing the game format (possession play vs. regulation goals and goalkeepers vs. small goals only) and the number of players (3 vs. 3, 5 vs. 5 and 7 vs. 7) influenced the physiological and physical demands of small-sided games (SSGs) in soccer in semiprofessional players. Fourteen semiprofessional male soccer players were monitored with global positioning system and heart rate devices. Heart rate, player load, distance covered, running speed, and the number of accelerations were recorded for 9 different SSGs. The results show that changes both in game format and the number of players affect the players' physiological and physical demands. Possession play places greater physiological and physical demands on players, although reducing the number of players only increases the physiological load. In the 7 vs. 7 games, changing the game format did not alter the heart rate responses. Finally, in the possession play format, changing the number of players did not produce significant differences in heart rate responses, although physical demands did decrease in line with a reduction in the number of players. These results should help coaches to understand how modifying different aspects of SSGs has a differential effect on the players' physiological and physical demands. Moreover, coaches in semiprofessional and amateur teams have now consistent information to design and optimize their training time in mixing the technical, tactical, and physical aspects.

Repeated sprint and change-of-direction abilities in soccer players: effects of age group.

The purpose of the present study was to compare the performance in repeated sprint ability (RSA) and repeated changes-of-direction (RCOD) among elite soccer players with different age categories. Forty-nine elite soccer players from the same club and from different age categories (Pro2: n = 8, U19: n = 18, U17: n = 13, and U15: n = 10) participated in this study. Each player was tested in both a RSA straight-line sprints (10 × 20 m with active recovery) and a RCOD test including four 100° COD at every 4 m (10 × 20 m with active recovery). The average time (AT), fastest time (FT), total time (TT), percentage of decrement score (%Dec), and RSA/RCOD index were recorded and calculated during all the RSA and RCOD tests. Results showed significant age group effects on RSA and RCOD parameters (p < 0.01) and RSA/RCOD index parameters (p < 0.01). Compared with other groups, U15 has significant (p < 0.05) higher values in RSA-AT, RSA-FT, RSA-TT, RCOD-AT, RCOD-FT, RCOD-TT, index-AT, index-FT, and index-TT. However, the trend of performance time and RSA/RCOD index was always similar (i.e., U15 > U17 > U19 > Pro2; Pro2 > U19 > U17 > U15) showing an age dependant for RSA and RCOD performance. The %Dec in RSA of U15 and U17 was significantly (p < 0.05) higher than U19 and Pro2, whereas the %Dec in RCOD of U15 was significantly (p < 0.05) higher than U19. In conclusion, the present study showed that the RSA and RCOD are age dependent, and therefore, coaches should plan a specific program differentiating the RSA and RCOD, while the individualized training could begin in U17.

Influence of different training regimes on physical and physiological demands during small-sided soccer games: continuous vs. intermittent format.

The aim of this study was to examine the physical and heart rate (HR) response of soccer players during 16 minutes of training using the same 5 vs. 5 small-sided game (SSG) in 3 different training regimes: a continuous format of 16 minutes and 2 intermittent formats (4 periods of 4 minutes; and 2 periods of 8 minutes) with the same work/rest ratio of passive recovery between the different periods (4:1). Ten male players (age 21.3 ± 3.4 years) belonging to a team of the third Spanish division participated in this study. Analyses were carried using a training regimen vs. drill time design (i.e., training × duration), that is, differentiating 2 training regimen (intermittent vs. continuous SSG formats) and the 4-minute periods (0-4, 4-8, 8-12, and 12-16 minutes) to determine the extent to which fatigue affected the variables studied in each regimen. During each SSG, HR and total distance covered in different speed categories and accumulated accelerations (i.e., training load) were measured. Results showed significant differences for (a) in intermittent format of 2 × 8 minutes, the distance covered at a speed of 7-12.9 km·h(-1) was greater in the 0- to 4-minute period than in the 12- to 16-minute period, and (b) the distance covered at a speed of 7-12.9 km·h(-1) during the 8- to 12-minute period was greater in intermittent format of 2 × 8 minutes than in continuous format (16 minutes). This study showed that drill regimen may affect physical responses during training SSG. The resulting evidence suggests that the continuous SSG format induces greater physical loads on players as compared with intermittent SSG format and that should help coaches to establish a better distribution of playing according to the objectives of the training.

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

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

Physical outcome in a successful Italian Serie A soccer team over three consecutive seasons.

The aim of this study was to examine the physical performance of a successful Italian Serie A team of more than 3 consecutive seasons. Twenty-five players participated in the study and were classified into 3 playing positions: defenders (n = 9), midfielders (n = 11), and forwards (n = 5). Activities match were studied by an analysis of multiple match camera SICS throughout the competition Italian Serie A matches played at home (n = 90) for 3 consecutive seasons (first: 2004/2005; second: 2005/2006; and third: 2006/2007). Total team ball possession and time-motion characteristics were examined. Results showed that total ball possession (52.1-54.9%) and the number of points accumulated at home (40/48) improved in the past 3 seasons, whereas the final rankings at home were stable. The total distances covered by minutes of play were significantly different between the 3 seasons (118.32 ± 6.69 m·min to 111.96 ± 8.05 m·min). Distance running and high-intensity activities were similar in the 3 seasons, whereas the distance covered in moderate-intensity running decreased in the third (p < 0.05). Variations between playing positions were found during the 3 consecutive seasons, with midfielders covering greater distances than defenders (p < 0.05) and forwards (p < 0.01). This study showed how for 3 consecutive seasons a Serie A team of successful players reduced their distances performed at submaximal speeds, and increased ball possession, while maintaining the high-intensity activities and the number of points at home. It is suggested that this is because of a better understanding of roles and tactics team organization and to act collectively and individually on these parameters to reduce energy expenditure during the game to maintain a high-level performance throughout the season.

Training Practices of Football Players During the Early COVID-19 Lockdown Worldwide.

The COVID-19 lockdown challenged the training options of athletes worldwide, including players from the most popular sport globally, football/soccer. PURPOSE: The authors explored the training practices of football players worldwide during the COVID-19 lockdown. METHODS: Football players (N = 2482, 30% professional, 22% semipro, and 48% amateur) completed an online survey (May-July 2020) on their training practices before versus during lockdown (March-June 2020). Questions were related to training frequency and session duration, as well as training knowledge and attitudes. RESULTS: Before lockdown, more professional (87%) than semipro (67%) and amateur (65%) players trained ≥5 sessions/wk, but this proportion decreased during the lockdown to 55%, 35%, and 42%, respectively. Players (80%-87%) trained ≥60 minutes before lockdown, but this proportion decreased to 45% in professionals, 43% in amateurs, and 36% in semipros during lockdown. At home, more than two-thirds of players had training space (73%) and equipment (66%) for cardiorespiratory training, while availability of equipment for technical and strength training was <50% during lockdown. Interactions between coach/trainer and player were more frequent (ie, daily) among professional (27%) than amateur (11%) and semipro (17%) players. Training load monitoring, albeit limited, was mostly performed by fitness coaches, more so with professionals (35%) than amateurs (13%) and semipros (17%). The players' training knowledge and attitudes/beliefs toward training were relatively modest (50%-59%). CONCLUSION: COVID-19 lockdown negatively affected training practices of football players worldwide, especially amateurs and semipros, for example, in training frequency, duration, intensity, technical, recovery, and other fitness training and coaching-related aspects. During lockdown-like situations, players should be monitored closely and provided appropriate support to facilitate their training.

Injury rates in professional soccer players during Ramadan.

Many of the socio-cultural lifestyle and dietary changes that take place during Ramadan may affect the risk of injury in athletes, but little evidence is available. The aim of the present study was to examine the effects over two consecutive years of the holy month of Ramadan on injury rates in 42 professional players of a Tunisian top-level professional soccer team. Players were retrospectively organized into fasting and non-fasting groups and monitored for 3 months: 4 weeks before Ramadan, during the month of Ramadan (4 weeks), and 4 weeks after Ramadan each year. During Ramadan, training started at 22.00 h. The circumstances (training/match) and mechanism of injury (traumatic/overuse) were recorded. No significant differences between the three periods were observed for weekly mean training load, training strain, training duration, and Hooper's Index (quality of sleep, and quantities of stress, delayed-onset muscle soreness, and fatigue). Compared with non-fasting players, fasters had a lower (P < 0.05) Hooper's Index and stress during and after Ramadan. No significant difference in injury rates was observed between fasting and non-fasting players. Nevertheless, the rates of non-contact (6.8 vs. 0.6 and 1.1) and training overuse (5.6 vs. 0.6 and 0.5) injuries were significantly higher in fasting players during the month of Ramadan than before or after Ramadan. In conclusion, Ramadan, along with the corresponding changes in nutritional habits, sleeping schedule, and socio-cultural and religious events, significantly increased overuse and non-contact injuries in fasting players despite the fact that the training load, strain, and duration were maintained.

Injury risk in professional football players with special reference to the playing position and training periodization.

AIM: The aim of this study was to examine injury incidence in professional football players according to the playing positions and with a special reference to training periodization. METHODS: A Spanish professional team was followed prospectively for the 2007-08 and 2008-09 seasons and exposure times and time-loss injuries were individually recorded during all training sessions and matches. Heart rate was monitored in all training sessions. RESULTS: total of 114 injuries were registered during the study period (mean injury incidence: 6.6 injuries per 1000 hours). The frequency of injuries was not uniformly distributed by playing positions (P<0.001), as forwards and central defenders sustained the greatest number of injury episodes and the highest match absence. Ligament sprains and muscle strains accounted for 50% of all injuries and 62% of all match absences. The highest incidence of sprains was achieved during pre-season and the beginning of the competition period. The risk to sustain a muscular strain peaked at the beginning and in the final weeks of the competition period and was related (r=0.72; P<0.05) to mean heart rate during the training stage. CONCLUSION: The results suggest that there exists a difference of injury risk according to the period of the season and therefore, injury prevention strategies should be introduced from pre-season. Moreover, training workloads should be controlled to avoid increasing the risk of muscle strains.