Fatigue In Soccer Players Research Articles

Performance of soccer players under acute physical fatigue: An approach based on cognitive, tactical and physical aspects

This study aimed to verify whether peripheral perception, tactical behaviour, and physical performance are influenced by acute physical fatigue in soccer players. The study included 24 trained soccer players (18.6 ± 1.5 years) from two Brazilian clubs. The TSAFT90 test was used to induce acute physical fatigue. The results showed that physical fatigue did not affect peripheral perception (p = 0.360). Regarding tactical behaviour, improved efficiency was observed for the principles of offensive coverage (p = 0.029), width and length with the ball (p = 0.044), and concentration (p = 0.008). On the other hand, a reduction was observed in the number of tactical actions of offensive coverage (p = 0.020) and recovery balance (p = 0.042). Also, improved accuracy in the principles of defensive balance (p = 0.009), recovery balance (p = 0.021) and defensive unity (p = 0.003) occurred under physical fatigue. A reduction in the physical performance outcomes total distance covered (p < 0.001), average speed (p < 0.001), sprints (p = 0.029), number of accelerations (p = 0.008) and decelerations (p = 0.008) were also detected. The internal (p < 0.01) and external (p < 0.01) workload was higher under physical fatigue. Overall, acute physical fatigue did not influence peripheral perception. However, physical performance was reduced under fatigue, the perceived effort increased, and tactical behaviours were affected by decreasing tactical actions performed near the ball, increasing errors in defensive movements in the lateral corridors and the last defensive line, and improving offensive tactical actions performance.

THE EFFECTIVENESS OF THE RECOVERY METHOD FOR MALUKU U-16 SOCCER PLAYER MSA THORANA ARU

This study aims to determine the effectiveness of several recovery methods to reduce the fatigue level of soccer players. The sample of this study was Thorana Aru, Maluku U-16 soccer player, aged 16.26 ± 2.5 years, with a body weight of 56.13 ± 11.84 kg, consisting of 32 people. The sample was divided into four groups using random sampling, namely the control group, active recovery, massage, and combined recovery, with a total sample of 8 people for each group. The objects in this study were the fatigue index and lactic acid levels in the blood, which were carried out by the initial test before recovery and the final test after recovery. The results showed that analysis of the fatigue index in the active recovery, massage, and combined recovery sample groups (p&lt;0.05) could reduce the fatigue index of soccer players. Testing lactic acid levels that occurred during active recovery and combined recovery (p&lt;0.05) showed that the two sample groups were effective in reducing lactic acid levels, whereas testing lactic acid levels in the massage sample group (p&gt;0.05) showed a decrease in lactic acid levels. Based on the results of the data analysis, it can be concluded that active recovery and combined recovery are effective in reducing the level of fatigue in soccer players.

A New Approach to Quantify Soccer Players’ Readiness through Machine Learning Techniques

Previous studies have shown that variation in PlayerLoad (PL) could be used to detect fatigue in soccer players. Machine learning techniques (ML) were used to develop a new locomotor efficiency index (LEI) based on the prediction of PL. Sixty-four elite soccer players were monitored during an entire season. GPS systems were employed to collect external load data, which in turn were used to predict PL during training/matches. Random Forest Regression (RF) produced the best performance (mean absolute percentage error = 0.10 ± 0.01) and was included in further analyses. The difference between the PL value predicted by the ML model and the real one was calculated, individualized for each player using a z-score transformation (LEI), and interpreted as a sign of fatigue (negative LEI) or neuromuscular readiness (positive LEI). A linear mixed model was used to analyze how LEI changed according to the period of the season, day of the week, and weekly load. Regarding seasonal variation, the lowest and highest LEI values were recorded at the beginning of the season and in the middle of the season, respectively. On a weekly basis, our results showed lower values on match day − 2, while high weekly training loads were associated with a reduction in LEI.

MENTAL FATIGUE IN SOCCER: A SYSTEMATIC REVIEW

ABSTRACT Fatigue in soccer players is traditionally investigated based on neuromuscular and metabolic factors. However, given that soccer is one of the sports that has the highest cognitive demand, it is believed that players' performance might also be influenced by the high levels of attention, and frequent decision-making required in soccer. This systematic review aimed to verify the effects of mental fatigue on physical, technical, tactical and cognitive performance of soccer players. We searched in the electronic databases Pubmed, Web of Science and Scopus, for articles published up to 30 April 2018. We included articles that used a protocol of mental fatigue through cognitive tasks performed prior to a physical or cognitive task related to soccer. Only studies that presented an experimental design with the control condition (without mental fatigue) and the experimental condition (with mental fatigue) were selected. A total of six articles met the inclusion criteria, one study by backward reference search and other through the authors' indication. The results showed smaller distances covered in physical tests, while the effects of mental fatigue on physical performance in small-sided games were not clear. In technical tests, there were more penalties in passes and less accuracy and speed when kicking the ball when players were in conditions of mental fatigue. Regarding the tactical variables, it was found that mental fatigue had a detrimental effect on the synchronization between team players and on individual tactical performance in defensive actions. In cognitive tests, based on video recordings of game play, negative effects on the players' speed and accuracy of decision-making were observed. According to the results of the literature search, it can be inferred that mental fatigue is a factor that has a negative influence on soccer performance. Level of evidence II; Systematic review.

Caffeine Supplementation and Physical Performance, Muscle Damage and Perception of Fatigue in Soccer Players: A Systematic Review.

Soccer is a complex team sport and success in this discipline depends on different factors such as physical fitness, player technique and team tactics, among others. In the last few years, several studies have described the impact of caffeine intake on soccer physical performance, but the results of these investigations have not been properly reviewed and summarized. The main objective of this review was to evaluate critically the effectiveness of a moderate dose of caffeine on soccer physical performance. A structured search was carried out following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines in the Medline/PubMed and Web of Science databases from January 2007 to November 2018. The search included studies with a cross-over and randomized experimental design in which the intake of caffeine (either from caffeinated drinks or pills) was compared to an identical placebo situation. There were no filters applied to the soccer players’ level, gender or age. This review included 17 articles that investigated the effects of caffeine on soccer-specific abilities (n = 12) or on muscle damage (n = 5). The review concluded that 5 investigations (100% of the number of investigations on this topic) had found ergogenic effects of caffeine on jump performance, 4 (100%) on repeated sprint ability and 2 (100%) on running distance during a simulated soccer game. However, only 1 investigation (25%) found as an effect of caffeine to increase serum markers of muscle damage, while no investigation reported an effect of caffeine to reduce perceived fatigue after soccer practice. In conclusion, a single and moderate dose of caffeine, ingested 5–60 min before a soccer practice, might produce valuable improvements in certain abilities related to enhanced soccer physical performance. However, caffeine does not seem to cause increased markers of muscle damage or changes in perceived exertion during soccer practice.

Effect of Maximal Anaerobic Loading on Lower Extremity Proprioceptive Sense in Soccer Players

This study was carried out to determine the effect of lower extremity muscle fatigue on proprioceptive sense in soccer players. 26 male soccer players who play licensed soccer in the amateur soccer teams of the Ağrı province and who was not injured in the past year (Age 20,03±3,38, weight 65,69±10,66, height 176,61±8,72) participated in the study voluntarily. The lactic acid concentration of the participants at rest and their proprioceptive sense measurements were determined by standardized methods and materials. Then, Wingate test was applied to the participants. The lactic acid concentration and proprioceptive sense measurements were repeated at the end of the test. The analysis of the collected data was carried out through the SPSS 22 program. Shapiro-Wilks test was conducted for normality distribution. Independent-Samples t-test was carried out in the comparison of test and control groups and Paired-Samples t-Test was utilized in the comparison of differences between pretest and posttest means. It was concluded that lower extremity fatigue in soccer players has a negative effect on lower extremity proprioceptive sense (p&lt;0.05).

The Effect of Branched Chain Amino Acids Supplementation (BCAA) on Muscle Damage and the Indicators of Fatigue in Soccer Players

The Effect of Branched Chain Amino Acids Supplementation (BCAA) on Muscle Damage and the Indicators of Fatigue in Soccer Players

Exploring the effects of mental and muscular fatigue in soccer players’ performance

This study examined the effects of induced mental and muscular fatigue on soccer players’ physical activity profile and collective behavior during small-sided games (SSG). Ten youth soccer players performed a 5vs5 SSG under three conditions: a) control, playing without any previous activity; b) muscular fatigue, playing after performing a repeated change-of-direction task; c) mental fatigue, playing after completing a 30 min Stroop color-word task. Players’ positional data was used to compute time-motion and tactical-related variables. The muscular fatigue condition resulted in lower distances covered in high speeds (∼27%, 0.3; ±0.5) than the control condition. From the tactical perspective, the muscular fatigue condition resulted in lower distance between dyads and players spent ∼7% more time synchronized in longitudinal displacements than the control condition (0.3; ±0.3). Additionally, players spent ∼14% more time synchronized with muscular fatigue than with mental fatigue (0.7; ±0.3). The mental fatigue condition resulted in a very likely more predictable pattern in the distance between dyads than in muscular fatigue condition (0.4; ±0.2). Also, the mental fatigue possibly decreased the teams’ stretch index when compared with control (0.2; ±0.3) and likely increased compared with muscular fatigue (0.5; ±0.5). The better levels of longitudinal synchronization after muscular fatigue, might suggest the usage of tactical-related tasks after intense exercise bouts. The lower physical performance and time spent longitudinally synchronized after mental fatigue, should alert to consider this variable before matches or training activities that aim to improve collective behavior.

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

ABSTRACTTo 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.

Psychophysiological indicators of fatigue in soccer players: A systematic review

Summary The aim of this study was to determine the main methods used to analyse the soccer players movement during games. Data were collected at three databases (PubMed, Medline and SPORTDiscus) from 2010 to 2015, using the match terms: “perceived exertion” AND “fatigue” AND “soccer”. The data criteria inclusion considered articles with match terms in titles and abstracts; studies purposes assessed central or peripheral fatigue in soccer players; psychological, physiological or psychophysiological variables; research design as a descriptive or experimental models. Studies that evaluated children, adults and recreational soccer practitioners were excluded. The studies quality was assessed by three PhD professors using the PEDro scale. Twenty-two studies were initially located; following the application of the eligibility criteria, 11 studies were selected for our analysis. Data showed that the main methods used to determine psychophysiological fatigue in athletes were ergoespirometry, but mainly indirect methods to identify aerobic power. For anaerobic power, the studies used mainly indirect tests (sprint and jump test). The Profile of Mood States and Illinois Agility Test were used to identify mood states and agility, respectively. For psychophysiological assessments were used mainly perceived exertion scales (Borg 6–20 and CR-10), Felt Arousal Scale, Feeling Scale, Hooper's Index and the SFMS questionnaire for the detection of early signs of overtraining, while for metabolic assessments were used the heart rate identified by heart monitor and blood lactate identified by lactimeter. Thus, this study concludes that indirect and cheap methods were reported to identify fatigue and psychophysiological changes during soccer matches and training session.

Effects of Two Different Half-Squat Training Programs on Fatigue During Repeated Cycling Sprints in Soccer Players

This study compared the effects of two different half-squat training programs on the repeated-sprint ability of soccer players during the preseason. Twenty male professional soccer players were divided into 2 groups: One group (S-group) performed 4 sets of 5 repetitions with 90% of their 1-repetition maximum (1RM), and the other group (H-group) performed 4 sets of 12 repetitions with 70% of 1RM, 3 times per week for 6 weeks, in addition to their common preseason training program. Repeated-sprint ability was assessed before and after training by 10 × 6-second cycle ergometer sprints separated by 24 seconds of passive recovery. Maximal half-squat strength increased significantly in both groups (p < 0.01), but this increase was significantly greater in the S-group compared with the H-group (17.3 ± 1.9 vs. 11.0 ± 1.9%, p < 0.05). Lean leg volume (LLV) increased only in the H-group. Total work over the 10 sprints improved in both groups after training, but this increase was significantly greater in the second half (8.9 ± 2.6%) compared with the first half of the sprint test (3.2 ± 1.7%) only in the S-group. Mean power output (MPO) expressed per liter of LLV was better maintained during the last 6 sprints posttraining only in the S-group, whereas there was no change in MPO per LLV in the H-group over the 10 sprints. These results suggest that resistance training with high loads is superior to a moderate-load program, because it increases strength without a change in muscle mass and also results in a greater improvement in repeated sprint ability. Therefore, resistance training with high loads may be preferable when the aim is to improve maximal strength and fatigue during sprinting in professional soccer players.