Performance In Soccer Players Research Articles

The effect of physical fatigue on the performance of soccer players: A systematic review.

This study aimed to carry out a systematic review to analyze, describe and discuss the effect of physical fatigue on the performance of soccer players. For this systematic review, searches were performed in Pubmed, Web of Science and SPORTDiscus electronic database until October 3, 2020, following the guidelines of PRISMA. A total of 12 articles met the inclusion criteria: i) healthy soccer players from any age group, competitive level or sex; ii) exposure to physical fatigue; iii) pre and post-physical fatigue conditions; iv) players’ cognitive, technical, physical and tactical performances and v) no restrictions regarding the study design. The results section was organized in four main dimensions: cognitive, technical, physical and tactical. Studies on cognitive performance have shown divergent results, varying according to the cognitive task employed and the physical protocol used. Regarding technical performance, negative effects of physical fatigue were found on the technical fundamentals of the pass, dribble and kick. With regard to physical performance, studies have shown a reduction in sprint capacity and distances covered at high velocity. Finally, the only study that analyzed the tactical performance in the field showed an increase in the team’s collective tactical behavior, but did not include analysis of the players’ individual tactical actions. In summary, the results of the analyzed studies show that the effect of physical fatigue on cognitive performance is inconclusive and that technical and physical performance are negatively affected. Regarding tactical performance, there is a lack of information on the topic in the current literature.

Relationship Between Variations Accumulated Workload and Sprint Performance in Elite Adolescent Soccer Players

Background: The aim of this study is to analyze the relationship between the accumulated training load parameters (i.e., acute (AWL), chronic (CWL), acute: chronic workload ratio (ACWR), training monotony (TM), and training strain (TS)) and sprint performance variations in elite adolescent soccer players, taking into account the maturation status of the players. Besides, we aimed to use regression models with mentioned parameters, sprint level, and peak height velocity (PHV) as predictors to explain variations in sprint performance during the in-season. Methods: Twenty-seven U16 soccer players (age: 15.5 ± 0.2 years, height: 171 ± 7.3 cm, body mass: 59 ± 6.1 cm, PHV: 14.4 ± 0.7) from one elite soccer national league club were evaluated. In this study was a cohort with monitoring the daily workload for 15 weeks in the competition season: early-season (EaS) weeks (w) W1 to W5; mid-season (MiS) W6 to W10; and end-season (EnS) W11 to W15. Anthropometric and PHV were assessed at the beginning of the season and sprint test was assessed before and after the season. Results: Results showed that there were some significant variations in workload parameters (sprint, AWL and TM) over a soccer season. Regarding comparisons between EaS vs. EnS, there were significant differences in Sprint (p ≤ 0.01; ES: –0.28) and CWL (p ≤ 0.01; ES: –0.80). Sprint performance can be estimated by ACWR, TM, TS and PHV values (R2 = 0.65). Conclusions: The present study revealed that sprint performance improved throughout the season in young soccer players, with significant intra-season variations, especially in CWL and ACWR load variables (Eas and Mid). In addition, it was observed that maturation did not have a significant effect on the change in sprint performance. This study clearly showed that there is a relationship between sprint performance and accumulated workload variables and that the significant change in sprint performance can be explained by load variables such as AWCR, TM, and TS.

Executive Functions, Physical Abilities, and Their Relationship with Tactical Performance in Young Soccer Players.

While tactical performance in soccer is associated with the players' and teams' collective actions in the context of game stimuli, how tactical performance relates to players' executive functions (EFs) and physical abilities should be examined. In this study, we examined these relationships among 81 Under-15 male soccer players who underwent tactical evaluation (FUT-SAT), EF tests (i.e.,(Stop-Signal Test and Design Fluency Test)), and physical tests (i.e.,(Maturity Offset, Yoyo Endurance Test II, Sargent Jump Test, and Sprint Test)). Multiple linear regression modeling with the stepwise method showed that approximately 48% of overall game tactical performance variance was explained by inhibitory control, biological maturation, and sprint capacity (p = .004; d = .54; r2 = .479), whereas 35% of offensive tactical performance variance was explained by the same dimensions (p = .001; d = .91; r2 = .353). In addition, approximately 28% of defensive tactical performance variance was explained by cognitive flexibility and aerobic resistance (p = .007; d = .39; r2 = .280). These results reflect the combined importance of EFs and physical abilities for tactical performance in young soccer players, suggesting that these abilities may be targets for training when trying to improve young players' performance.

Influence of Upper and Lower Body Anthropometric Measures on An Aggregate Physical Performance Score in Young Elite Male Soccer Players: A Case Study

Background: The present study aimed to determine the association of anthropometry-based characteristics with an aggregate score (AS) of physical performance in young elite soccer players. Methods: Sixteen under 15 elite players were enrolled. Among numerous anthropometrics variables, upper arm contracted (UACC) and relaxed circumference (UARC), corrected arm muscle area (AMAcorr), arm muscle circumference (AMC), thigh muscle circumference (TMC) and suprapatellar girths were also employed in this study. Players’ physical performance was assessed by the change of direction (COD), 10 m and 20 m sprint, countermovement jump (CMJ) test, sprint with 90∘ turns (with ball), and yo-yo intermittent recovery test level 1 (Yo-Yo IRT1). The AS was computed by Principal Components Analysis technique with one component on normalized performance results. A stepwise regression analysis was conducted to assess potential association between anthropometry-based variables and AS. Results: Large negative correlations (r < –0.68) of AS with UACC, UARC, AMAcorr, and AMC were detected. UACC and TMC permits to accurately estimate AS explaining 60% of the total variance (p < 0.001). Conclusions: These findings demonstrated the importance of including anthropometry-based measures of both upper and lower body to the physical performance potential expressed by AS in elite youth soccer.

Within-subject variation of technical performance in elite Brazilian professional soccer players: the environmental stress, match location, and opposition’s ranking influences

ABSTRACT Recent research identified that the behaviour of players and teams varies depending on the match context affecting the players’ technical performance. Due to the high context variability of a soccer game, understanding the characteristics of technical performance in soccer can enable coaches to make better decisions. The present study aimed to evaluate the effects of environmental stress, match location, and opposition’s ranking on technical performance variation of elite soccer players from strong and weak teams from the Brasileirão Serie A (Brazilian First Division National Championship). Fourteen match actions were chosen as dependent variables in the analysis. Values of each action of each player per match were established. We compared the means of these values from the Top 4 and Bottom 4 teams across different match contexts (environment heat stress, match location, and opposition’s ranking). We calculated all comparisons using linear mixed models. The results showed better technical performance under low or medium environmental heat stress at home and against weak opposition (p < 0.05). Therefore, match context affects elite Brazilian soccer players’ technical performance from the first division championship.

THE RELATIONSHIP BETWEEN JUMP PERFORMANCE, SPEED AND COD SPEED IN ELITE FEMALE SOCCER PLAYERS

The purpose of this study was to present the physical performance of elite female soccer players and to analyze the relationship between jump performance, speed and COD ability. Sixteen elite female soccer players (age: 20.05±2.85; height: 166.47±4.83cm; body weight: 60.52±8.30kg, BMI 21.88±2.86) from a women's club who played the highest rank of the competition took part in this study. The jump, speed and COD abilities of each player were determined using: (1) the Squat jump (SJ), (2) Countermovement Jump (CMJ), countermovement jump with arm swing (CMJA), (2) running speed at 30-m with passing time at 10m and 20m, (3) the pro agility test (pro), (4) zig-zag test (zig-zag), (5) 9-6-3-6-3 sprint (9-6-3-6-9). The results of Pearson’s correlation indicated moderate significant relationships between the 10m running speed and pro agility test (r=0.59; p&lt;0.01), as well as the zig-zag test (r=0.55; p&lt;0.01), and also between the 30m and all COD tests (pro agility r=0.66; p&lt;0.01, zig-zag r=0.59; p&lt;0.01 and 9-6-3-6-9 r=0.58; p&lt;0.05). A small correlation (r=0.49; p&lt;0.03) was noticed between the 10m running test and 9-6-3-6-9 agility test, and also between the CMJA (r=0.45; p&lt;0.05) and the 9-6-3-6-9 agility test. The findings of the present study indicated a significant correlation between speed and all of the COD tests, additionally between the CMJA and 9-6-3-6-9 COD test. Therefore, elite female soccer players with higher maximum acceleration rates and speed tend to perform better in change of direction tests. On the other hand, jump performance does not significantly correlate with COD ability.

Immediate and Acute Effect of Self Myofascial Release vs Instrument Assisted Soft Tissue Mobilization on Flexibility, Strength and Sport-Specific Performance in Young Male Soccer Players

Background: Regular exercise and performance can result in microtrau-ma, which is minor damage to the muscle. The resulting inflammatory response may lead to fascia scar tissue over time, which in turn may lead to muscular dysfunction. Purpose: The purpose of our study was to compare the immediate and acute effects of SMR and IASTM on flexibility, strength and sport-specific performance in young male soccer players. Method: Twenty-seven young male soccer players were randomly assigned to receive either SMR via plain foam roller or IASTM via M2T blade. To compare the effect of interventions, subjects were assessed on measures of flexibility via sit and reach test, power through vertical jump test, agility by Illinois agility test, 20m sprint test and strength test by a dynamometer. Results: A one-way ANOVA was used to analyze differences. To test for the difference between interventions and across 3 assessments, a 3X3 split plot ANOVA with a group (control, SMR, IASTM), time (0 min, 10 mins, 20 mins) and interaction effect (Group X Time) was employed. There was a significant difference in strength during performance without intervention vs. immediately after SMR and IASTM (p=0.03). Conclusion: The findings of the study suggest that SMR and IASTM did not improve physical performance in young male soccer players, but they did not hinder performance either. Even if performance does not improve, there does not seem to be any adverse effect by using either SMR or IASTM before physical activity, athletes need not be discouraged from using these tools.

근막이완술을 활용한 청소년 축구선수 운동수행능력 향상요인에 관한 연구

Purpose There has been no study yet to confirm the effect of myofascial release before exercise on adolescent soccer players. The purpose of this study is to investigate the effects of myofascial release on exercise performance function, pain, and body composition in male adolescent soccer players. Methods 30 male high school soccer players were participated in this study. Myofascial release was applied for 50 minutes at a time, and was performed three times a week for eight weeks (24 sessions). Before and after intervention, soccer function, pain intensity, and body composition were assessed. Results After applying myofascial release, significant improvements in soccer function (p < 0.05) and pain (p < 0.05) was confirmed, but body composition did not show significant change. This study showed that 8-week myofascial release applications are effective in improving the athletic performance of adolescent soccer players and relieving pain. Conclusion Based on the results of this study, it is supported that the application of myofascial release before exercise will help soccer players improve their performance by improving their athletic performance and relieving pain.

The effect of mid-season coach turnover on running match performance and match outcome in professional soccer players

The aim of this research was to examine the physical match performance and match outcome before and after coach turnover in professional soccer teams compared with a control group containing coaches working continuously for 3 consecutive seasons. Analysed data included 325 performances of teams led by dismissed coaches (DC), 313 of teams led by new coaches (NC), and 580 of teams led by unchanged coaches (UnC). Variables, such as average number of collected points, total distance (TD), total distance per minute (TD/min), high-speed running (HSR), sprinting and number of high-intensity runs (NHIR), were analysed in the last 15 games of DC and 15 matches of NC. These periods were divided into 3 blocks out of 5 matches (5-match blocks). NC collected a significantly higher number of points than DC (p = 0.015), whereas average points collected by UNC were significantly greater than DC (p < 0.001 and NC (p = 0.012). TD and TD/min for DC were significantly lower (p < 0.001) compared with both NC and UnC, whereas significant differences in HSR (p = 0.003) and NHIR (p = 0.03) were identified between DC and NC. The current study reported that mid-season coach turnover may result in short-term improvement in team results and physical match performance. However, this effect disappears after a period of approximately 5 games.

Evolution of determinant factors of maximal sprinting and repeated sprint ability in women soccer players

The present study aimed to determine the influence of force–power–velocity, vertical and horizontal jumps, and repeated sprint ability on the sprinting performance of adult women soccer players. Eighteen women soccer players from one team participating in the first female national Spanish soccer league were analyzed. Fitness assessments were performed twice in a period of three months. The following assessments were made to reach the aim of the study: (1) anthropometric measures, (2) CMJ (0%, 20% and 40%), (3) hop test (dominant and nondominant leg), (4) linear sprinting at 30 m and (5) RSA test. The main evidence of this study revealed the meaningful contribution of lower-limb power (vertical and horizontal jump), maximal sprint and peak power on sprinting time performance, while stride frequency was meaningfully explained by vertical jump and maximal sprinting. In fact, positive moderate and large correlations were found between Time and CMJ, CMJ 20%, CMJ 40%, Hop Test Dominant and Non-dominant, and Pmax and MS of Force–Power–Velocity (r = − 0.73, p = 0.001; r = − 0.68, p = 0.002; r = − 0.51, p = 0.03; r = − 0.64, p = 0.004; r = − 0.57, p = 0.013; r = − 0.78, p = 0.001, and r = − 0.83, p = 0.001, respectively). In sum, peak power, maximal speed, and lower-limb power (in vertical and horizontal jumps) were significant determinants of sprinting performance (time), while vertical jump was the determinant of stride frequency. In addition, our findings suggest that potentiation and explosive vertical power could be the emphasis for sustaining the stride frequency of women soccer players, while sprinting performance should be supported by strong acceleration and maximal velocity sustained by both vertical and horizontal force and concentric and eccentric strength and power.

The effect of eight weeks beetroot juice supplement on aerobic, anaerobic power, and field performance of soccer players

ABSTRACT The purpose of the study investigated the effect of eight weeks of soccer training with beetroot juice supplement on aerobic power, anaerobic power, and field performance of soccer players. This is experimental research, by the control group in pre and post-test. The statistical population was male soccer players. Forty subjects were randomly divided into four groups including the exercise group (EX) the exercise group with beetroot juice supplement (EX&BRJS) the beetroot juice supplement group (BRJS), and the control group (C). Aerobic power, anaerobic threshold, and respiratory exchange ratio, measured by the gas analyser (Cosmed), anaerobic power (peak, mean power), and fatigue index, by Wingate cycle test (Monark, 839), and field performance by (Bangsbo, field test performance). The statistical methods include the Kolmogorov-Smirnov, Levin, covariance (ANCOVA), and pair comparison with Bonferroni test. The results showed eight weeks’ of soccer training with beetroot juice supplement, significantly changed aerobic power, respiratory exchange ratio, anaerobic threshold, anaerobic power, field performance, and fatigue index (P ≤ 0.05). Additionally, in all variables, the paired comparison showed that the EX&BRJS group progressed more than all other condition groups. The soccer athletes may use beetroot juice supplements along with soccer exercises to improve aerobic and anaerobic power and field performance.

Perceptual-Cognitive Tasks Affect Landing Performance of Soccer Players at Different Levels of Fatigue.

Background There is a possible interaction between the underlying mechanisms of perceptual-cognitive tasks and motor control. For example, landing biomechanics changed during perceptual-cognitive tasks undertaken at different levels of fatigue of the athlete. Thus, this study explored the effect of perception-cognitive tasks interventions on male soccer players' landing mechanisms at different levels of fatigue. Methods Perceptual-cognitive tasks during games were simulated using classic multiple object tracking (MOT) paradigms, and 15 male soccer players completed MOT tasks under nonfatigue (NF), moderate fatigue (MF), and severe fatigue (SF). Landing-associated indicators were collected and calculated using a Vicon and force measuring platform. Results Level of fatigue and MOT task significantly affected hip and knee flexion angles, hip and knee extension moments, and vertical ground reaction force. Specifically, hip and knee flexion angles were significantly higher in MOT than non-MOT tasks at all levels of fatigue. In NF state, hip and knee extension moments were significantly smaller during MOT than non-MOT tasks. In SF state, the hip extension moment was larger during MOT than non-MOT tasks. In both MF and SF states, vertical ground reaction force was significantly higher in MOT than non-MOT tasks. Conclusion Although soccer players landed cautiously when not fatigued, they were significantly less able to do this and handle challenging perceptual-cognitive task movements when fatigued. Thus, landing performance is affected by perceptual-cognitive task interference in fatigue conditions.

How Coaches Can Improve Their Teams' Match Performance-The Influence of In-Game Changes of Tactical Formation in Professional Soccer.

The tactical formation has been shown to influence the match performance of professional soccer players. This study aimed to examine the effects of in-game changes in tactical formation on match performance and to analyze coach-specific differences. We investigated three consecutive seasons of an elite team in the German Bundesliga which were managed by three different coaches, respectively. For every season, the formation changes that occurred during games were recorded. The match performance was measured on a team level using the variables “goals,” “chances,” and “scoring zone” entries (≙successful attacking sequence) for the own/opposing team. Non-parametric tests were used to compare the 10 min before with the 10 min after the formation change, as well as games with and without formation change. In the 10 min after the formation change, the team achieved more goals/chances/scoring zone entries than in the 10 min before the formation change (mean ES = 0.52). Similarly, the team conceded fewer opposing goals/chances/scoring zone entries in the 10 min after the formation change (mean ES = 0.35). Furthermore, the results indicate that the success of the respective formation change was dependent on the responsible coach. Depending on the season, the extent of the impacts varied (season 1: mean ES = 0.71; season 2: mean ES = 0.26; and season 3: mean ES = 0.22). Over all three seasons, the formation changes had a positive effect on the match performance of the analyzed team, highlighting their importance in professional soccer. Depending on the season, formation changes had varying impacts on the performance, indicating coach-specific differences. Therefore, the quality of the formation changes of the different coaches varied. The provided information can support coaches in understanding the effects of their in-game decisions.

Does Technical Match Performance in Professional Soccer Depend on the Positional Role or the Individuality of the Player?

The aim of the study was to examine the impact of the positional role and the individuality on the technical match performance in professional soccer players. From official match data of the Bundesliga season 2018/19, technical performance [short (<10 m)/medium (10–30 m)/long (>30 m) passes, dribblings, ball possessions] of all players who played during the season were analyzed (normative data). Five playing positions (center back, full back, central midfielder, wide midfielder and forward) were distinguished. As the contextual factor tactical formation is known to influence match performance, this parameter was controlled for. Further, those players who played at minimum four games in at least two different playing positions were included in the study sample (n = 13). The technical match performance of the players was analyzed in relation to the normative data regarding the extent to which the players either adapted or maintained their performance when changing the playing position. When switching playing positions, positional role could explain 3–6% of the variance in short passes and ball possessions and 27–44% of the variance in dribblings, medium passes, and long passes. Moreover, we observed large interindividual differences in the extent to which a player changed, adapted, or maintained his performance. In detail, five players clearly adapted their technical performance when changing playing positions, while five players maintained their performance. Coaches can use these findings to better understand the technical match performance of single players and further, to estimate the impact of a change in the positional role on the technical performance of the respective player.

The effects of jump training on measures of physical performance, lower extremities injury incidence and burden in highly trained male soccer players

ABSTRACT This study aimed to analyse the effects of a 16-week jump training program on the physical performance and lower extremities injury profile in semi-professional male soccer players. Participants were randomly assigned to the control group (CG; n = 13; age = 21.7 ± 3.6 years) or the experimental group (EG; n = 10; age = 22.3 ± 3.5 years). Countermovement jump (CMJ) height (cm), 30 m linear sprint time (s) with split times at 10 m and 20 m distances, and change of direction speed (CODS; 10 + 10 m with 90° turn) time (s) with turns using the dominant or non-dominant leg, were assessed before and after the intervention. Lower extremity injuries sustained throughout the intervention period were collected. Significant within-group improvements were found in EG in CMJ (p = 0.01; effect size [ES] = 1.03; large). Additionally, between-group difference after intervention was found in CMJ (F = 4.42; p = 0.013) in favour of EG. Injury burden was 194.86 (CG) vs 71.37 (EG) days of absence/1,000 h (RR = 2.73; 95% CI 2.10–3.54; p < 0.001). No other significant within-group or between-group differences were found. In conclusion, compared to regular soccer training, jump training was effective to improve jumping ability and burden in soccer players.

Assessment of Body Composition and Physical Performance of Young Soccer Players: Differences According to the Competitive Level.

Simple SummaryIn recent years, soccer teams require greater physical and technical-tactical capabilities from not to younger players, especially in elite team. Although dribble and kicking skills, strength, endurance, speed, and agility abilities are the most relevant features, it is not clear whether anthropometric and body composition aspects could be considered appropriate talent characteristics in soccer players. In addition, it rests unclear which are the principal differences, when they appear, and what metrics discriminate between elite and non-elite teams. The main aim of this study is to compare anthropometric, body composition and physical performance between and within four juvenile categories of two (elite and non-elite) soccer teams and investigates factors that better discriminate among two teams. Despite the physical performance results as the most relevant factor in discriminating among the two soccer societies, the elite players report better anthropometric and body characteristics, especially in the youngest categories.Soccer is a multifactorial sport, in which players are expected to possess well developed physical, psychological, technical, and tactical skills. Thus, the anthropometric and fitness measures play a determinant role and could vary according to the competitive level. Therefore, the present study aimed to verify differences in body composition and physical performance between two soccer team. 162 young soccer players (from the Under 12 to Under 15 age categories; age: 13.01 ± 1.15 years) of different competitive levels (elite—n = 98 and non-elite—n = 64) were recruited. Anthropometric characteristics (height, weight, lengths, widths, circumferences, and skinfold thicknesses (SK)), bioelectrical impedance, physical performance test as countermovement jump (CMJ), 15 m straight-line sprints, Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo), and 20 + 20 m repeated-sprint ability (RSA)) were carried out. In addition, Body mass index (BMI), body composition parameters (percentage of fat mass (%F), Fat mass (FM, kg), and Fat-free mass (FFM, kg)) and the areas of the upper arm, calf and thigh were calculated, and the Bioelectric Impedance Vector Analysis (BIVA) procedures were applied. In addition, a linear discriminant analysis was assessed to determine which factors better discriminate between an elite and non-elite football team. Many differences were observed in body composition between and within each football team’s category, especially in triceps SK (p < 0.05), %F (p < 0.05), and all performance tests (p < 0.01). The canonical correlation was 0.717 (F(7,128) = 19.37, p < 0.0001), and the coefficients that better discriminated between two teams were 15 m sprint (−2.39), RSA (1−26), suprailiac SK (−0.5) and CMJ (−0.45). Elite soccer team players present a better body composition and greater physical efficiency. In addition, BIVA outcome could be a relevant selection criterion to scout among younger soccer players.

Effects of a competitive half-season on the aerobic capacity and match running performance of Turkish elite professional soccer players

This study examines how exertion during matches affects participants’ physical capacity and match performance. The study included 13 elite football league players (21 ± 0.7 years old; height, 181.1 ± 8.98 cm; body mass, 74.7 ± 8.1 kg) and used global positioning system (GPS) data collected during 12 official matches. Four matches after the first Yo-Yo IR1 test, four matches before the second Yo-Yo IR1 test, and four matches after the second Yo-Yo IR1 test are examined. Sprint count per minute (SC) (N/min), (&gt;19 km/h), p &lt; 0.030; distance covered at zone 4–6 per minute DCZ4 (km/h/min), (18–24 km/h), p &lt; 0.00; distance covered at zone 4–6 per minute DCZ5 (km/h/min), (24–30 km/h), p &lt; 0.001; and distance covered at zone 4–6 per minute DCZ6 (km/h/min), (30–39 km/h), p &lt; 0.001 were recorded. According to the values obtained before the tests, the match data show a decreasing trend in the following weeks. Furthermore, the relationship between physical performance values and tests is determined (average speed (AS) (km/h), r = 0.64; maximum speed (MS) (km/h), r = 0.50; DCZ4 (km/h/min), r = 0.89; DCZ5 (km/h), r = 0.81). As a result, time-dependent changes in intermittent endurance capacity during matches validated in-game running kinematics. This indicates the Yo-Yo IR1’s robustness as a fitness marker, and its capacity to help practitioners preview longitudinal variations in locomotor behavior during matches. Athletes who show a high degree of asymmetry in official matches seem to exhibit a strong ability to resist fatigue during testing.

Consequences of the SARS-CoV-2 Infection on Anaerobic Performances in Young Elite Soccer Players.

The COVID-19 pandemic required local confinement measures reducing sport practice with possible consequences on the athletes’ performances. Furthermore, anaerobic detraining was underestimated and poorly known in adolescents. This article aimed to assess the effects of SARS-CoV-2 infection and 1-month COVID-19 confinement on jump testing in young elite soccer players despite a 1-month multimodal training program followed by a 1-month soccer retraining period. Thirty-one elite soccer players aged 14 were included; 16 were infected by the SARS-CoV-2 and compared with 15 non-infected elite soccer players before and after 1 month of COVID-19 confinement, and after 1 month of a soccer retraining period. Squat jumps (SJ), countermovement jumps with (CMJs) and without arm swinging (CMJ) and multiple consecutive jumps (stiffness) were used to explore the anaerobic performances. Analysis of variance for repeated measures was used to compare the positive and negative SARS-CoV-2 groups, taking into account the confinement period (low training) and the retraining soccer period. The jump tests were not altered in the positive SARS-CoV-2 group compared to the negative SARS-CoV-2 group after confinement (SJ: 31.6 ± 5.6 vs. 32.7 ± 3.7; CMJ: 34.1 ± 6.9 vs. 34.2 ± 2.6; CMJs: 38.6 ± 6.8 vs. 40.3 ± 3.9; stiffness: 28.5 ± 4.3 vs. 29.1 ± 3.7) and at 1 month of this period (SJ: 33.8 ± 5.5 vs. 36.2 ± 4.6; CMJ: 34.7 ± 5.5 vs. 36.4 ± 3.5; CMJs: 40.4 ± 6.7 vs. 42.7 ± 5.5; stiffness: 32.6 ± 4.7 vs. 34.0 ± 4.3). The SARS-CoV-2 infection had no consequence on anaerobic performances assessed by jump tests in adolescent soccer players. The adolescents’ growth could explain the absence of alteration of jump performances during the COVID-19 confinement. These results can be useful to manage the recovery of the anaerobic fitness after SARS-CoV-2 infection occurring in adolescent athletes.

The Association between Multidirectional Speed Performance, Dynamic Balance and Chronological Age in Young Soccer Players.

The ability to maintain a stable single-leg balance stance during a fast change of direction movement is a fundamental aspect both for improving sport-specific skills and for prevention strategies. The aim of this cross-sectional study was to investigate the associations between multidirectional speed performance (MDS), dynamic balance performance (DBP), and chronological age in young and uninjured soccer players. In addition, it was examined whether chronological age and balance can predict variance in speed performance. One-hundred forty-six young male soccer players (age range 11–19) performed the y-balance test (YBT) and the lower extremity functional test (LEFT). Descriptive statistics, Pearson correlation, and multiple regression analysis were executed. The analyses were carried out on the further variables: for the DBP, the YBT composite score % (CS dominant leg/CS non-dominant leg) and limb symmetry index % (LSI) were used; for the MDS, the LEFT time in seconds (s) was used. Findings revealed LEFT scores to have a significant association with chronological age (p = 0.000), CS dominant (p = 0.019) and LSI (p = 0.044) of the YBT. In addition, CS dominant and chronological age explained the variance of the LEFT by 44%, regardless of LSI. To conclude, MDS revealed a strong association with DBP of the dominant side but a small association with LSI. In addition, a small association was found between quick LEFT times and older players. Finally, MDS variance can be predicted from DBP of the dominant side and chronological age in young soccer players. The tests used in this study could be useful screening tools for the detection of performance deficits, the implementation of prevention training programs, and the optimization of selection strategies in soccer academies.

The influence of tactical formation on physical and technical match performance in male soccer: A systematic review

The number of investigations that specifically address the influence of formation on soccer performance has increased in recent years. Since there is no overview that summarizes these effects, this systematic review aims to synthesize the available literature on the effects of tactical formation on physical and technical match performance. According to the PRISMA 2020 guidelines, a systematic search was performed (Databases: PubMed and Web of Science). Studies were included, if they reported any physical (e.g., sprinting distance) or technical (e.g., number of passes) match performance parameters and compared at least two different formations. The study outcomes were synthesized descriptively. The effect of formation on physical performance was investigated in ten studies while three studies investigated the effect on technical performance (11 studies included). The studies revealed that formation has an effect on the physical and technical match performance of soccer players both in a team and at a positional level. On a team level, smaller differences were observed for formations that are similar in the number of players in each playing position (i.e., 4-5-1, 4-2-3-1). Furthermore, physical match performance was higher in formations with three defenders (e.g., 3-5-2) in comparison to formations with four defenders (e.g., 4-4-2). On a positional level, all positions were affected in a similar way by formation. Therefore, formation affects the physical and technical match performance of soccer players and if the playing position is also considered, the results become even more meaningful. The studies were very heterogeneous regarding their methodology (i.e., parameters, sample size). The findings can help coaches to design their training programs and to prepare the players for a specific positional role depending on the tactical formation.