Soccer Performance Research Articles

Longitudinal Investigation of Lateral Asymmetry Reduction: Exploring the Impact of Bilateral Practice on Soccer Skill Development in Young Players

Background: The research on the role of bilateral practice is a topic examined by multiple studies to explore the connection between laterality and soccer performance. Objectives: The purpose of the current investigation was to explore the effects of longitudinal practice on (1) performance asymmetry, (2) age, and (3) the influence of bilateral practice on the lateral asymmetries of soccer skills in young players. Methods: Fifteen right-footed participants participated in three soccer skill tests: Lob pass with right (LPR) and left (LPL) foot; Shooting accuracy with right (SHR) and left (SHL) foot; Ball control with the body with right (BCR) and left (BCL) foot, and by alternate (BCAlt). These tests were repeated at 12 years old (U12) (Test 1: T1), 14 years old (U14) (Test 2: T2), and 15 years old (U15) (Test 3: T3), respectively. Results: The results indicated no impact of longitudinal practice on the reduction of lateral asymmetries concerning lob pass and shooting accuracy across U12, U14, and U15. However, a notable reduction in lateral asymmetries was observed exclusively in ball control with the body by alternance in U15 and U14 compared to U12 (P < 0.01 and P < 0.001, respectively). Conclusions: We showed improvement of performance with both sides. We suggest that extensive bilateral practice is essential to improve the podal performance of soccer skills.

Effects of Acute Ingestion of Guarana (Paullinia Cupana) on Soccer Player Performance: A Randomized, Cross-over, Placebo-Controlled Study

Objective To investigate the acute effects of ingesting a beverage containing guarana (Paullinia cupana) seed powder on performance during field tests related to physical capacities that are determinants of soccer performance, such as lower limb power, sprint, agility, and the capacity to carry out intermittent exercise. Methods The study was conducted using a randomized, crossover, and counterbalanced design, with a beverage containing guarana or placebo administered in a double-blind manner. Twenty-seven under-17 soccer players of a professional soccer club performed a battery of tests 60 min after the ingestion of guarana (3 g of the fruit seed powder) or placebo. Trials were performed with a 7-day washout period. The battery of tests included a countermovement jump test, sprints of 10 and 20 m, an Illinois agility test, and a Yo–Yo Intermittent Recovery Test level 1 (YYIR1). Results Guarana ingestion did not improve countermovement jump, sprints, or agility (p > 0.05). However, guarana ingestion increased the distance covered in the YYIR1, compared with placebo ingestion (p = 0.01). Conclusion Acute ingestion of guarana improves the capacity to perform intermittent exercise in soccer players but seems to be ineffective to improve lower limb power, sprint, and agility.

Impact of game format and age group on technical performance in youth football

This study aimed to analyse technical action variations among 5, 7, 9, and 11-a-side game formats and investigate the effects of age groups (U8, U10, U12, and U14) on these actions. A total of 197 soccer players aged between 6.94 ± 0.7 and 13.46 ± 0.5 years participated, with three matches conducted weekly, totalling 48 matches. Two-way ANOVA was employed to analyse age group and game format as independent factors. The study revealed the influence of age group on players' technical actions variability: front pass success p < .001; side pass success p < .001; back pass success p < .001; short pass success p < .001; reception success p < .001; goal p < .002; unsuccessful short pass p < .001; unsuccessful long pass p < .001; ball contacts p < .001. Additionally, the study highlighted the impact of game format on success rates: front pass success p < .001; side pass success p < .001; back pass success p < .001; short pass success p < .001; reception success p < .001; goal p < .036; shot on target p < .001; ball contacts p < .001; interception p < .001. These findings enhance understanding of how game format and age group affect technical performance in youth soccer, emphasizing the need for interventions that optimize players’ development trajectories.

Summarizing physical performance in professional soccer: development of a new composite index

The aims of this study were to create a composite index to measure the overall players’ physical performance in professional soccer matches and analyze the effect of individual playing time and positional differences on this composite index. A total of 830 official matches from LaLiga men’s first division and Spanish Copa del Rey were analyzed, which resulted in 24,980 match observations collected from 1138 male players (forwards, n = 286; midfielders, n = 441; defenders, n = 411). The physical performance variables, which represent the locomotor demands, were collected using electronic performance tracking systems. A Partial Least-Squares Structural Equation Model (PLS-SEM) was used to measure performance. The PLS-SEM output had three significant latent components, which explained 95% of the initial variability, that were related to the acceleration-specific performance (component 1), high-intensity running-related variables (component 2), and medium intensity actions variables (component 3). Also, a linear regression analysis was used to explore relationships between playing activity time (hours—X axis) and the composite index (10-point scale—Y axis), in which a strong and positive correlation was observed between individual playing time and the composite index (r = 0.76; p < 0.001; R2 = 0.58). Also, significant positive correlations were observed in forwards (r = 0.85; p < 0.001; R2 = 0.74), midfielders (r = 0.80; p < 0.001; R2 = 0.64), and defenders (r = 0.67; p < 0.001; R2 = 0.45). However, significant differences between playing positions with a small effect size (p < 0.05; eta-squared = 0.01) were found. From a practical perspective, this study may serve as a reference for sports performance practitioners to create a composite index that measures the overall players’ physical performance. The instructions to create this index are available in the manuscript.

Exploring the behavioral indicators of resilience in professional academy youth soccer

The capacity to demonstrate resilience is important for performance and development outcomes in youth soccer. A key feature of resilience is the demonstration of positive behavioral responses to pressures or setbacks, yet little research exists on the specific behaviors that characterize resilience in the youth soccer literature. This study aimed to explore the behavioral indicators of resilience through focus groups and interviews with 60 participants from six professional soccer academies and one National Soccer Governing Body. The data was collected in two phases, the first involved a discussion of the observable behaviors associated with resilience in youth soccer. In the second phase, participants reflected on examples of resilience behaviors alongside video clips. These acted as a stimulus to contextualize the behaviors arising from the first phase. Content analysis was used to analyze the data and 36 behaviors were identified across six themes: (a) teammate support-focused (e.g., verbal support following mistakes), (b) emotion-focused (e.g., displaying emotional regulation), (c) effort-focused (e.g., physical efforts to overcome challenge), (d) rebound (e.g., positive reactions to a mistake), (e) robust (e.g., showing composure when under pressure), and (f) learning-focused (e.g., willingness to accept feedback). The results offer an insight into a multifaceted range of resilience behaviors in the context of youth soccer. With this knowledge, practitioners can make informed decisions around player development by assessing specific behavioral metrics related to resilience, players can engage in structured self-reflection practices pertaining to resilience development, and researchers can work toward the development of validated observational tools for resilience assessment.

Match running performance preceding scoring and conceding a goal in men’s professional soccer

This study aimed to investigate the potential differences in the match running performance of professional soccer players 5 min. before scoring and conceding a goal in the Polish Ekstraklasa. The sample consisted of 278 matches with 570 goals scored during official matches of the 2022/23 Polish Ekstraklasa season. All data was collected utilising the computerised multiple-camera optical tracking system TRACAB. Total distance covered (TD), standing distance (StD; < 0.72 km h−1), walking distance (WD; 0.73–7.2 km h−1), jogging distance (JG; 7.21–14.4 km h−1), running distance (RD; 14.41–19.8 km h−1), high-speed running distance (HSR; 19.81–25.2 km h−1) and sprinting distance (SprD; > 25.2 km h−1) were analysed in 5-min intervals prior to a goal scored for both teams. The employed linear mixed models showed that all examined match-running performance metrics were higher in teams that scored a goal compared to teams that conceded a goal. Within 5 min before scoring a goal in Polish Ekstraklasa matches, the scoring team produced significantly greater TD (∆ 95%CI 256.8–300.4 m; p = 0.001), WD (∆ 95%CI 52.3–95.8 m; p = 0.001), JG (∆ 95%CI 100.5–144.1 m; p = 0.001) and RD (∆ 95%CI 16.2–59.8 m; p = 0.001) compared to the conceding team, although no differences were found for HSR and SprD. These results demonstrate the enhanced identification potential of key physical performance factors influencing goal scoring in the Polish Ekstraklasa, thereby optimising the training process and improving overall performance. To enhance the effectiveness of soccer training, coaching and performance staff should consider this study's findings, that indicate an increase in the volume of medium- and low-intensity running efforts preceding a goal.

Coach Education: The Relationship between Lower Extremity Flexibility and Vertical Jump Performance in Soccer

The aim of this study was to investigate the relationship between lower extremity flexibility values and vertical jump performance of elite soccer players. Twenty-six young elite male soccer players voluntarily participated in the study. Age, height, and weight of the participants were determined as descriptive statistics. Lower extremity flexibility (.=ROM) test and vertical jump (counter movement jump=CMJ) performance determination test were applied to the participants. A goniometer was used for lower extremity flexibility measurement and My Jump 2 application, which has proven its validity and reliability, was used for CMJ performances. Descriptive characteristics of the participants included in the study were mean age: 16.23 ±.51 years, height: 172.96 ±7.56 cm, body weight: 63,15±7,69 kg. The mean values of CMJ performance of the participants were: 37,54±5,51; the mean value of lower extremity flexibility angles (ROM) was 115±4,99°. According to the data obtained, a statistically significant relationship was observed between ROM and CMJ performance characteristics of elite soccer players (p=.008) (p&lt;0.05). According to the results obtained, a significant relationship was found between ROM and CMJ performances of soccer players. It can be said that teaching the importance of flexibility exercises to soccer players in soccer training programs and including them in training programs will positively affect the sudden power output performances of soccer players such as jumping.

Assessment of Maximum Oxygen Uptake in Elite Youth Soccer Players: A Comparative Analysis of Smartwatch Technology, Yoyo Intermittent Recovery Test 2, and Respiratory Gas Analysis.

The maximum oxygen uptake (VO2max) is a critical factor for endurance performance in soccer. Novel wearable technology may allow frequent assessment of V̇O2max during non-fatiguing warm-up runs of soccer players with minimal interference to soccer practice. The aim of this study was to assess the validity of VO2max provided by a consumer grade smartwatch (Garmin Forerunner 245, Garmin, Olathe, USA, Software:13.00) and the YoYo Intermittent Recovery Run 2 (YYIR2) by comparing it with respiratory gas analysis. 24 trained male youth soccer players performed different tests to assess VO2max: i) a treadmill test employing respiratory gas analysis, ii) YYIR2 and iii) during a non-fatiguing warm-up run of 10 min wearing a smartwatch as recommended by the device-manufacturer on 3 different days within 2 weeks. As the device-manufacturer indicates that validity of smartwatch-derived VO2max may differ with an increase in runs, 16 players performed a second run with the smartwatch to test this claim. The main evidence revealed that the smartwatch showed an ICC of 0.37 [95% CI: -0.25; 0.71] a mean absolute percentage error (MAPE) of 5.58% after one run, as well as an ICC of 0.54 [95% CI: -0.3; 8.4] and a MAPE of 1.06% after the second run with the smartwatch. The YYIR2 showed an ICC of 0.17 [95% CI: -5.7; 0.6]; and MAPE of 4.2%. When using the smartwatch for VO2max assessment in a non-fatiguing run as a warm-up, as suggested by the device manufacturer before soccer practice, the MAPE diminishes after two runs. Therefore, for more accurate VO2max assessment with the smartwatch, we recommend to perform at least two runs to reduce the MAPE and enhance the validity of the findings.

A large-scale multivariate soccer athlete health, performance, and position monitoring dataset

Data analysis for athletic performance optimization and injury prevention is of tremendous interest to sports teams and the scientific community. However, sports data are often sparse and hard to obtain due to legal restrictions, unwillingness to share, and lack of personnel resources to be assigned to the tedious process of data curation. These constraints make it difficult to develop automated systems for analysis, which require large datasets for learning. We therefore present SoccerMon, the largest soccer athlete dataset available today containing both subjective and objective metrics, collected from two different elite women’s soccer teams over two years. Our dataset contains 33,849 subjective reports and 10,075 objective reports, the latter including over six billion GPS position measurements. SoccerMon can not only play a valuable role in developing better analysis and prediction systems for soccer, but also inspire similar data collection activities in other domains which can benefit from subjective athlete reports, GPS position information, and/or time-series data in general.

The impact of soccer-specific psychophysiological stress on inhibition and cognitive flexibility in elite youth players

While researchers and practitioners attribute an essential role to executive functions (EFs) for soccer performance, the usefulness of respective diagnostics and the predictive value remain unclear. One limitation restricting the translation and relevance of study results to improve actual game performance is the insufficient consideration of competitive conditions. Thus, this study aimed to conduct soccer-specific cognitive diagnostics under a soccer-specific psychophysiological stress condition, mimicing the demands of a competitive game. A total of 92 (Mage = 15.17, SDage = 1.45) youth elite players performed tests for inhibition (flanker task) or cognitive flexibility (number-letter task) with a soccer-specific motor response (i.e., pass into goals). After a pre-test in a neutral condition, players were randomly assigned to a neutral (moderate soccer-specific exercise) or a stress condition (physical stress and competitive instructions and filming for psychological stress). Objective (i.e., cortisol, heart rate variability) and subjective stress-related measures (i.e., SAM, VAS) were assessed six times throughout experimental procedure. Analyses revealed significant interaction effects between time and condition for all objective and subjective variables indicating a successful experimental stress induction. For cognitive performance, results revealed significant main effects of time, but no significant interaction effects between time and condition. However, descriptive statistics suggested improved performance under stress, with decreased flanker effect and switch costs. Additionally, response time variability in the flanker task significantly decreased in the stress condition. These findings offer insights into individual stress perception and processing under game-related psychophysiological demands, expanding previous research on situational EF alterations that also hold relevance for applied practitioners.

Sequencing Effects of Concurrent Strength and Endurance Training on Selected Measures of Physical Fitness in Young Male Soccer Players: A Randomized Matched-Pairs Trial

BackgroundVarious physical fitness qualities such as muscle strength, speed and endurance are related to soccer performance. Accordingly, the combination of strength and endurance training (i.e., concurrent training [CT]) is an often-encountered training regimen in soccer. Less is known about the effects of CT sequencing on performance in young soccer players. The aim of this study was to assess the sequencing effects of strength and intermittent endurance training applied within the same training session (intrasession) on measures of physical fitness and soccer performance in young soccer players.MethodsFifty male adolescent soccer players volunteered to participate in this study which was conducted in the Netherlands in 2019. Players were randomly assigned to a strength-endurance (SE) or an endurance-strength (ES) group in matched pairs based on their countermovement jump (CMJ) performance at baseline. Both groups completed a 12-weeks in-season training program with two weekly CT sessions. Training sessions consisted of 15 min plyometric exercises and 15 min soccer-specific intermittent endurance training. Both groups performed the same training volumes and the only difference between the groups was the CT intrasession sequencing scheme (SE vs. ES). Pre and post intervention, proxies of muscle power (CMJ, squat jump [SJ]), linear sprint speed (30-m sprint test), agility (Illinois test with / without ball), and soccer performance (ball kicking velocity) were tested.ResultsData from 38 players aged 14.8 ± 1.0 years (body height 172.9 ± 8.1 cm, body mass: 57.0 ± 7.2 kg, soccer experience: 8.8 ± 2.8 years, age from peak-height-velocity [PHV]: +1.2 ± 1.0 years) were included. Significant main time effects were found for CMJ (p = 0.002, d = 0.55), SJ (p = 0.004, d = 0.51), the Illinois agility test with ball (p = 0.016, d = 0.51), and ball kicking velocity (p = 0.016, d = 0.51). Significant group-by-time interactions were observed for 30-m linear sprint speed (p < 0.001, d = 0.76) with ES showing greater improvements (p = 0.006, d = 0.85, Δ-5%).ConclusionsBoth CT-sequencing types improved performance in the tests administered. The intrasession CT sequencing (SE vs. ES) appears not to have a major impact on physical fitness adaptations, except for linear sprint speed which was in favor of ES.

Validation of Step Detection and Distance Calculation Algorithms for Soccer Performance Monitoring.

This study focused on developing and evaluating a gyroscope-based step counter algorithm using inertial measurement unit (IMU) readings for precise athletic performance monitoring in soccer. The research aimed to provide reliable step detection and distance estimation tailored to soccer-specific movements, including various running speeds and directional changes. Real-time algorithms utilizing shank angular data from gyroscopes were created. Experiments were conducted on a specially designed soccer-specific testing circuit performed by 15 athletes, simulating a range of locomotion activities such as walking, jogging, and high-intensity actions. The algorithm outcome was compared with manually tagged data from a high-quality video camera-based system for validation, by assessing the agreement between the paired values using limits of agreement, concordance correlation coefficient, and further metrics. Results returned a step detection accuracy of 95.8% and a distance estimation Root Mean Square Error (RMSE) of 17.6 m over about 202 m of track. A sub-sample (N = 6) also wore two pairs of devices concurrently to evaluate inter-unit reliability. The performance analysis suggested that the algorithm was effective and reliable in tracking diverse soccer-specific movements. The proposed algorithm offered a robust and efficient solution for tracking step count and distance covered in soccer, particularly beneficial in indoor environments where global navigation satellite systems are not feasible. This advancement in sports technology widens the spectrum of tools for coaches and athletes in monitoring soccer performance.

Neurocognitive Performance, Vestibulo-Ocular Function and Postural Control in Youth Male Soccer and Basketball Players of Different Ages

Neurocognitive Performance, Vestibulo-Ocular Function and Postural Control in Youth Male Soccer and Basketball Players of Different Ages

Assessment of Performance in Youth Soccer Players: Should We Consider the Maturation Status?

The influence of biological maturity status on talent identification and development in youth soccer has been debated extensively. Alternative methods have thus recently emerged to estimate maturity status, such as the Pubertal Development Scale (PDS), but their relationship with physical capabilities of young soccer players still needs to be determined. The present study investigated the relationships of different PDS-derived pubertal status measures, chronological age, and relative age with selected performance variables in youth soccer. Sixty-one male soccer players were assessed for physical capabilities using field tests for sprinting, vertical jumps (countermovement jump, CMJ), intermittent high-intensity endurance, and repeated sprint ability. Chronological age was defined as the number of days since birth, and relative age was defined in terms of age quarters. PDS-derived measures of puberal status, otherwise, were determined as an average PDS score, a PDS category score, and a pubertal category. Chronological age, relative age, and measures of pubertal status were scarcely related (p > 0.05) to selected measures of soccer performance. Significant correlations were only found between different measures of pubertal status and the variable "work" in the CMJ test (range r = 0.33-0.36; p < 0.01) and between chronological age and CMJ height (r = -0.297; p = 0.02). The present results suggest that physical performance of young soccer players is poorly related to chronological age, relative age, and pubertal status. Potential effects of biological maturity status on physical capabilities may not be easily identifiable in a group of young soccer players narrowed in terms of chronological age and training status.

Lower-Body Power, Body Composition, Speed, and Agility Performance among Youth Soccer Players.

Speed and agility have been described as crucial abilities for soccer players. The purpose of this study was to analyze, in detail, the variance in speed and agility tasks explained by lower-body power after controlling for age and body composition. The participants were 96 male soccer players aged 16.1 ± 1.6 years. Body composition (stature, body fat percentage-BF%, body mass, and fat-free mass-FFM), lower-body power (countermovement jump-CMJ, and squat jump-SJ), speed (5-, 10-, and 35 m sprints), and agility (t-test) were assessed. Among body composition parameters, BF% presented the highest number of significant relationships with speed and agility, with the strength of correlations ranging from small (5 m sprint, r = 0.25) to large (35 m sprint, r = 0.52). The strongest correlation coefficient emerged between FFM and the 35 m sprint (r = -0.65). Significant correlations were found between vertical jump performance and the 35 m sprint (CMJ: r = -0.68; SJ: r = -0.69), followed by the t-test (CMJ: r = -0.35; SJ: r = -0.47). The hierarchical multiple regression model could explain 22% to 67% of the variance observed in agility scores and speed. BF% remained the most statistically significant negative predictor of all regression models. The CMJ remained a statistically significant positive predictor of the 35 m sprint (β = -0.581, p ≤ 0.01) after controlling for age and body composition. Integrating programs targeting lower-body power might be important to enhance speed and agility performance in youth soccer. On the other hand, future research based on multidisciplinary approaches to investigate the effects of nutritional strategies in reducing or preventing gains in BF% is still needed, which remained a significant predictor of sprint and agility performance in the final models.

Effect of re-warm-up practices on brain networks and physical performance in soccer players

Objectives: The warm-up (WU) and re-warm-up (R-WU) regimes in many team sports, especially football and competition, plays an essential role in improving physical function and increasing communication between brain networks. The present study aimed to evaluate the effects of the R-WU on brain networks and physical performance in young soccer players.Methods: After familiarizing the laboratory conditions, twelve young male soccer players (age 18.2± 0.5 years) performed only one WU protocol, which included 25 minutes and two parts of general and specialized warming up in one session. In addition to warming up in the next session, the participant performed an R-WU that included four sets of plyometric movements, five jumps from obstacles to a height of 40 cm, followed by crossing the agile ladder. Functional magnetic resonance imaging (fMRI), 20m speed, and Illinois test were used to evaluate the function of brain networks and physical function.Results: The subjects showed a significant increase in the performance of both speed and agility in the R-WU session compared to the warm-up session (P≤0.01). Also, a positive relationship was observed between the performance of default, executive, and attention networks in the R-WU session compared to the WU session (P≤0.01, P≤0.03). Conclusions. The present study demonstrated that the R-WU program improved the relationship between brain networks and physical function in soccer players.

The Importance Of Vo2 Max In Young Soccer Players

"Soccer is a high-level skill sport that requires aerobic and anaerobic strength, as well as physical skills related to speed, agility, strength, and power. To meet these physical needs of soccer players, coaches now offer a variety of aerobic exercises that essentially use the lower and upper extremities, as well as large muscle groups. Correct technical performance of exercises protects not only from various injuries but also saves unnecessary energy consumption. For this reason, the purpose of this research is to critically analyze research that has examined the importance of aerobic endurance in young soccer players. The following databases were searched: Pub Med, Scopus, Google Scholar, CrossRef, etc. to find all relevant publications. The following keywords were used in this search: ""soccer"", ""young soccer players"", ""VO2 max"", and ""soccer performance"", along with adjectives such as ""effect"", ""change"" and ""impact"". It was found that the aerobic demands of soccer players are crucial and strategic for the game. Keywords: ""soccer"", ""young soccer players"", ""VO2 max"", ""soccer performance"", ""effect"", ""change"" and ""impact""."

Biomechanical load quantification of national and regional soccer players with an inertial sensor setup during a jump, kick, and sprint task: assessment of discriminative validity

Training load quantification methods may help optimize soccer performance. However, whole-body indicators potentially underestimate biomechanical load. A new inertial sensor setup allows joint-specific biomechanical load quantification. Good discriminative validity further supports the use of this method, and therefore the purpose of this study is to assess the discriminative validity of this method during soccer-specific activities. Twelve national and sixteen regional soccer players wore an inertial sensor setup and performed countermovement jumps, soccer kicks, and 30 m sprints. Between-group differences in angular acceleration-based biomechanical load indicators Knee Load, Hip Load, and performance were assessed using MANOVAs and Cohen’s effect sizes. Furthermore, relationships with performance were explored. National players showed higher Knee Load during jumping (mean difference: 0.11 A.U., ES = 0.93, p = 0.02), kicking (mean difference: 1.94 A.U., ES = 0.94; p = 0.02), and almost during sprinting (mean difference: 12.85, ES = 0.77; p = 0.05). Hip Load did not differ between groups across all tasks, although national players outperformed regional players on all tests. Significant relationships between Knee Load (rjump = 0.41, rkick = 0.65), Hip Load (rjump = 0.42), and performance were observed with 95% confidence intervals ranging from trivial to large. The results confirm discriminative validity of Knee Load for jumping and kicking, but not for sprinting and Hip Load in general. The confidence intervals of the established relationships suggest that the biomechanical loads might not entirely explain between-group differences in performance. The results can be used as reference values for biomechanical load quantification in the field.

Repeated-sprint sets test: a new method for evaluating and forecasting fitness in elite young male soccer players

The objective of the current study was to explore the correlation between repeated sprint sets (RSS) ability and several physical attributes, including maximum sprint speed, maximal aerobic speed, maximal anaerobic speed, aerobic capacity, and explosive strength. Moreover, the aim was to assess the suitability of RSS as a comprehensive evaluation tool for physical qualities and to determine which physical field tests most accurately predict RSS in elite young male soccer players. A total of thirty-two young elite male soccer players (mean age 14.6 ± 0.3 years; predicted years from peak height velocity (PHV): − 0.4 ± 0.3; years in training: 3.7 ± 0.5) voluntarily participated in the study. The players participated in eight consecutive specific physical tests, with a minimum 72-h recovery between each session to minimize the impact of fatigue during the second trial. The participants completed the tests in the following order: RSS test, Vam-Eval test, a constant velocity test performed until exhaustion at 100% of vVO2max (tlim100), 20-m Multi-Stage Shuttle Run test (VMSRT), Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1), Maximal Anaerobic Shuttle Running Test (VMASRT), Maximal Sprinting Speed Test (20-m flying sprint), Countermovement Jump (CMJ), and Standing Long Jump test (SLJ). The results of the study showed that there were very large negative correlations between tlim100 and SST (sum of sprint times), and large negative correlations between Yo-Yo IR1, Vam-Eval, and SST during RSS in young elite male soccer players (p < 0.05). Additionally, VMASRT and SLJ demonstrated a moderate negative correlation with SST (p < 0.05). In contrast, significant positive correlations were found between 20-m flying sprint and the SST (p < 0.05). According to the stepwise multiple linear regression analysis, the primary predictors of SST, ranked by importance, were tlim100 and Yo-Yo IR1. These two predictors collectively accounted for 72% of the variance in players’ SST (p < 0.0001). Due to the importance of aerobic capacity and short repeated accelerations/sprint sets for overall competitive performance in soccer, in conclusion, our results suggest that elite young male soccer players should perform both high intensity interval training and aeorobic capactity exercises as part of soccer training if the primary outcome is to improve repeated sprint ability performance.

The interaction between acute emotional states and executive functions in youth elite soccer players.

Executive functions (EFs) are relevant for game performance in soccer and have been investigated in previous research. However, emotions are a well-known performance factor in sport competitions, which may affect performance by means of EFs. The diagnostic of EFs has mainly been performed disregarding the potential impact of emotional states. Thus, we aimed to initially analyze interaction between emotional states and EFs in two studies with male youth elite soccer players. In the first study, 105 players (Mage = 14.97) completed computerized tasks assessing inhibition, cognitive flexibility and working memory. In the second study, 92 players (Mage = 15.17) performed adapted and validated tests of inhibition (n = 45) or cognitive flexibility (n = 47) in a soccer-specific setting (SoccerBot360). Emotional and affective states were assessed using the German Sport Emotion Questionnaire and self-assessment manikins. For the computerized tasks, results showed a significant negative correlation between switch costs accuracy and tension, r = 0.28, indicating lower error rates with higher levels of tension. In contrast, in the SoccerBot360 we found significant positive correlations for response time and tension (no-switch: r = 0.38; switch: r = 0.39) representing prolonged response times related to tension. Further, for soccer-specific inhibition, positive emotions were significantly positively correlated with response time (congruent: r = 0.32; incongruent: r = 0.32). Subsequent regression analyses also demonstrate that valence and arousal effectively explain variance in cognitive performance parameters under neutral conditions. Accordingly, the ambiguity of the results suggests high variability in EF performance, affective and emotional states as well as a potentially moderating influence of other variables such as context and task difficulty. Thus, future cognitive diagnostic research should integrate assessments of emotional and affective states as these may contribute to situational fluctuations in EF performance.