Exploring countermovement jump variables across competitive levels and playing positions in futsal.

Introduction: The aims of this study were to compare several countermovement jump (CMJ) kinetic variables between professional (PRO) and semi-professional (SEMI-PRO) futsal players and examine the differences amongst playing positions. Methods: CMJ performance from 56 male futsal players (25.2 ± 4.8 years; weight: 74.4 ± 6.4 kg) was analysed. Players were separated into PRO (n = 29; 27.0 ± 4.4 years; 75.4 ± 6.0 kg) and SEMI-PRO (n = 27; 22.7 ± 4.3 years; 73.1 ± 6.8 kg), and according to playing position: defenders (n = 16; 25.4 ± 3.7 years; 75.2 ± 6.0 kg), wingers (n = 26; 23.5 ± 4.5 years; 72.0 ± 6.9 kg), and pivots (n = 14; 28.0 ± 5.6 years; 77.8 ± 4.3 kg). Linear mixed models and effect sizes were used for the analyses based on the mean of two jumps for each variable. Results: PRO players presented a deeper center of mass (COM) displacement (p = 0.002, ES = 0.83), greater eccentric (Ecc) absolute (p = 0.019, ES = 0.61) and relative peak power (p = 0.046, ES = 0.52), and achieved greater Ecc peak velocities (p = 0.004, ES = 0.76) when compared to SEMI-PRO. Non-significant and trivial-to-small differences were observed in all the other CMJ variables according to the competitive level and playing position. Discussion: Ecc capabilities (i.e., deeper COM displacement, greater Ecc absolute and relative peak power, and peak velocity) during vertical jump seem to differentiate PRO and SEMI-PRO players. However, CMJ variables do not discriminate amongst playing positions in futsal players.

Special Issue "Sports Science in Children".

In recent times, research and technological advancements have opened an unprecedented window of opportunity for sports science to play a pivotal role in the holistic well-being of children [...].

The Effects of Players' Rotations on High-Intensity Activities in Professional Futsal Players.

The current study aimed to investigate the effects of interchange rotations on players` physical performance during competition, with special reference to high-intensity activity (HIA) according to the playing position. Physical performance data, collected from 19 professional players during seven official matches from the Spanish futsal league using a portable local positioning system, included the number of high-speed running activities (>18 km·h-1), high-intensity accelerations (>3 m·s-2), and high-intensity decelerations (>3 m·s-2). Statistically significant (p ≤ 0.05) differences were observed in the number of HIA efforts across rotations and between positions. Players performed more HIA efforts in the first rotation (n = 17.6), suggesting that their first rotation was more demanding than all subsequent rotations. Wingers demonstrated a higher HIA effort and frequency of HIA efforts when compared to defenders (p ≤ 0.05) and pivots (p ≤ 0.001). For all positions, the first rotation was more physically demanding as the number of HIA efforts per rotation decreased with an increased number of rotations throughout the match. Furthermore, higher HIA profile positions, such as wingers and defenders, were less likely to maintain consistent HIA properties (repetition number, time-frequency, and the work-rate) across subsequent rotations during the match. The findings of the study can inform coaching decisions regarding players' rotations to maintain consistent HIA performance throughout the match.

Tracking devices and physical performance analysis in team sports: a comprehensive framework for research-trends and future directions.

Background: Tracking devices, such as global (GPS) and local (LPS) positioning systems, combined with physiological measurements, have become reliable tools to characterize movement patterns, assessing the external load (EL), internal load (IL), fatigue, and performance of athletes in team sports. This scoping review aims to provide a comprehensive understanding of the applicability of tracking systems in physical performance analysis within team sports and the wellbeing of athletes based on research strategies and combined variables. Methods: A systematic search was conducted in PubMed, Web of Knowledge, and Scopus databases according to PRISMA guidelines. The 79 studies that were reviewed met the following criteria: (1) contained relevant data regarding elite athletes' performance; (2) athletes' EL and IL; (3) were written in the English language; (4) were related only to team sports. Results: The findings indicate that tracking technology has been engaged in several research areas, including performance analysis, training vs. match load management, injuries, and nutrition, through characterization and correlational studies. Metrics, primarily focused on kinematic and mechanical EL aspects, have been employed in combination with IL data to analyze the performance of athletes. However, the lack of an integrative model for the analysis and integration of EL and IL metrics within each team sport suggests an interesting direction for further research. Conclusion: There is a need for coherence between the methods and the research goals on performance analysis. The development of a framework that guides experimental studies is highly recommended, particularly on manipulating metrics analyzed between training and match sessions, injury prevention, and nutrition. This will lead to the development of the most applied sports science research to improve the preparation and decision-making of athletes based on reliable data. Systematic Review Registration: https://inplasy.com/?s=2022120039, identifier 2022120039.

The assessment of the match performance of association football referees: Identification of key variables.

The purpose of this study was to understand the contribution of each performance indicator to evaluate match performance of football referees. Thirty-four elite Referee Match Observers (RMOs) from the Portuguese FA participated voluntarily in the study. From the official assessment sheet of each game, the referee's game score was categorized in two groups according to referee's game score: i) Referees with a Low Score (LFS) and ii) Referees with High Score (HFS). A multivariable binary logistic regression model was used to assess the relationship between the Performance Indicators (PIs) of the dimensions i) game difficulty and game intervention and ii) disciplinary actions and game management in relation to the referee's match assessment score. The model proposed revealed that only the PIs negative application of the laws of the game and referee teamwork, from the dimension disciplinary actions and game management, significantly defined the final game referee's assessment score. This study suggests that the PIs scored by the RMOs contributed in a different way to the referee's game score. The model explains 60.4% of the referee's game score based on the variables referee teamwork and negative application of the laws of the game.

Interpreting match performance in elite futsal: considerations for normalizing variables using effective time.

Introduction: This study aimed to investigate the physical and individual technical-tactical performance of elite futsal players. Methods: Thirteen National Team futsal players (27.4 ± 4.7 years, 70.3 ± 7.6 kg, 176.3 ± 5.5 cm) competed in 15 official matches in three distinct competitions. Session rate of perceived exertion (sRPE) and player load (PL) were measured for assessing physical internal and external load, respectively. Individual tactical actions were analyzed using Instat Scout®, considering variables such as fouls, shots, shots on target, goals, successful dribbles, passes, successful passes, ball losses, ball recoveries, and challenges won. Results: The cluster analysis classified the players into two groups: "high-involvement" (HIGH) and "low-involvement" (LOW), based on their average effective playing time, sRPE, and PL. A linear mixed model was used to examine the differences in external and internal load and technical-tactical variables between the two groups, accounting for individual repeated measures. Considering absolute values, HIGH players presented higher sRPE, RPE, total PL, shots, goals, passes, successful passes, ball losses and recoveries, and challenges won (p = 0.001-0.039; ES = 0.43-2.48), when compared to their LOW counterparts. However, when analyzed relative to effective time, LOW players reached higher total PL and shots per minute (p = 0.001-0.012; ES = 0.39-0.93) when compared to HIGH players. Non-significant differences were found for the rest of the variables. Discussion: In summary, these results emphasize the importance of normalizing internal and external load variables and technical-tactical performance variables per effective playing time in futsal. The current findings indicate that players with lower involvement can present the same or even higher physical and technical-tactical performance compared to teammates with more playing time.

Epidemiology of Injuries in Elite Male Futsal Players.

OBJECTIVE: This study aimed to describe and characterize injuries sustained by elite male futsal players in Portugal. DESIGN: Prospective cohort study. SETTING: Top-tier Portuguese league in the 2019 to 2020 season. PARTICIPANTS: One hundred sixty-seven players from 9 elite/international-level (tier 4) futsal teams. INDEPENDENT VARIABLES: The location, type, body side, body part, mechanism of injury, severity, occurrence, days lost, training, and match exposure were collected. MAIN OUTCOME MEASURES: Injury incidence, prevalence, and burden. RESULTS: The study was conducted during an 8-month season. A total of 133 injuries were recorded, and 92 (67.6%) players sustained injuries. The overall time-loss injury incidence was 4.5 injuries per 1000 hours of exposure. Injury incidence during matches was higher than during training sessions (25.9 vs 3.0 per 1000 hours of exposure, respectively). Average time loss was 9 days, and moderate injuries were the most frequent (44%), followed by mild injuries (24%). Injury burden was 73.8 days lost per 1000 hours of total player exposure. Sprains/ligament (29%) and muscle rupture/tear/strains (32%) were the most common injuries. The groin (19%), thigh (17%), knee (19%), and ankle (15%) were the most affected body areas. Noncontact injuries were the most reported mechanism (65%), and 24% were overuse injuries. CONCLUSIONS: This study showed that elite/international-level (tier 4) male futsal players are more prone to noncontact injuries, primarily affecting the lower limbs. The incidence during match play increased by 9-fold compared with training sessions.

The Road to Becoming a World Champion in Futsal.

PURPOSE: The aim of the current study was to report the training program and monitoring outcomes of the Portuguese national futsal team during the preparation and competition phases of the FIFA Futsal World Cup Lithuania 2021™. For that, the variations in training load and wellness were measured, as well as their relationship. METHODS: The study followed a retrospective cohort design. For all field training sessions, the volume, exercise structure, and area of play were identified. Player load, session rating of perceived exertion (sRPE), and wellness were collected. Descriptive statistics and Kruskal-Wallis tests were used for comparison purposes. A visualization method was used for load and well-being. RESULTS: No significant differences were observed in the number of training sessions, session duration, and player load between preparation and competitive periods. sRPE showed significantly higher values in preparation than in competition periods (P < .05, d = 0.86) and significant differences between weeks (P < .05, d = 1.08). Wellness showed a general statistical difference between periods (P < .001, d = 1.28) and weeks (P < .05, d = 1.17). The correlation analysis for the overall period revealed a general linear relationship within variables of training load and wellness (P < .001). Variations occurred for preparation and competition periods. The visualization method through quadrant plots allowed us to understand the adaptation of the team and the players over the specific period under analysis. CONCLUSIONS: Through this study, it was possible to better understand the training program and monitoring strategies of a high-performance futsal team over a high-level tournament.

Exploring the Effects of Tasks with Different Decision-Making Levels on Ball Control, Passing Performance, and External Load in Youth Football.

This study aimed to understand how the design of decision-making tasks affects youth football players' ball control, passing performance, and external load. A total of 16 male youth football players (age: 12.94 ± 0.25 years) competed in various tasks based on the following levels of decision-making: (i) low decision-making (Low DM), which consisted of a predefined ball control and passing sequence; (ii) moderate decision-making (Mod DM), which consisted of maintaining possession in a square with four players and two balls while maintaining the same position; and (iii) high decision-making (High DM), which consisted of a 3 vs. 3 + 2 neutral players ball possession game. The study design consisted of a pre-post design (a 6 min pre-test game, a 6 min intervention, and a 6 min post-test game). The players' ball control and passing performance were measured using the game performance evaluation tool and notational analysis, while GPS data were used to determine their physical performance. The pre-post test analysis revealed decrements in players' ability to identify more offensive players after the Mod DM task (W = 9.50, p = 0.016), while there was an increase in their ability to receive the ball towards the space following the High DM task (t = -2.40, p = 0.016). Analysis between groups showed lower values in most ball control variables for the Low DM task compared to the Mod DM task (ball control execution, p = 0.030; appropriateness, p = 0.031; motor space, p = 0.025), while there were also lower values in the distance covered while sprinting (p = 0.042). Overall, prescriptive tasks (Low DM) that are repetitive in nature may affect players' perceptual attunement, whereas static tasks (e.g., Mod DM) may limit their ability to locate players in more offensive positions. Moreover, game-based situations (High DM) seem to acutely enhance players' performance, possibly due to contextual dependency. Overall, coaches should carefully consider the type of practice structure when designing tasks that aim to improve players' technical skills in youth football.

The Use of Wearable Technologies in the Assessment of Physical Activity in Preschool- and School-Age Youth: Systematic Review.

In recent years, physical activity assessment has increasingly relied on wearable monitors to provide measures for surveillance, intervention, and epidemiological research. This present systematic review aimed to examine the current research about the utilization of wearable technology in the evaluation in physical activities of preschool- and school-age children. A database search (Web of Science, PubMed and Scopus) for original research articles was performed. A total of twenty-one articles met the inclusion criteria, and the Cochrane risk of bias tool was used. Wearable technology can actually be a very important instrument/tool to detect the movements and monitor the physical activity of children and adolescents. The results revealed that there are a few studies on the influence of these technologies on physical activity in schools, and most of them are descriptive. In line with previous research, the wearable devices can be used as a motivational tool to improve PA behaviors and in the evaluation of PA interventions. However, the different reliability levels of the different devices used in the studies can compromise the analysis and understanding of the results.

How weekly monitoring variables influence players' and teams' match performance in elite futsal players.

This study aimed to investigate how weekly training load constrains the performance of players and teams in official futsal competitions. Data from a professional male team were collected during two seasons (46 weeks). The applied monitoring system analysed the training load (as measured by session perceived exertion, sRPE), the total recovery status (TQR), the well-being score (WBs) and the variability of neuromuscular performance during each week (CMJ-cv). In addition, the performance was assessed for all the matches. A path analysis model was performed to test the associations across variables. Results from the path analysis model revealed that it explains 31% of the teams' performance. In general, the results show that previous team performance has no significant effects on the training week. A significant negative relationship was found between CMJ-cv and match performance (ß = -.34; CI95% -.359 to -.070), as well as a significant negative relationship between players' match performance and the team's match performance (ß = -.55; CI95% -.292 to .740). Regarding indirect effects, only a negative association between CMJ-cv and team match performance via players' match performance (ß = -.19; CI95% -.342 to -.049) was identified. The small variation of the weekly CMJ (CMJ-cv) seems to be a key variable to monitor and explain both player and team performance. Based on this model, and only looking at the physical variables, it was possible to explain 31% of the team's performance. Longitudinal and multi-team studies should be conducted to integrate other technical, tactical and psychological variables that allow the level of understanding of players' and teams' performance to be improved.

How Football Players' Age Affect Passing Patterns of Play According to Field Location.

This study aimed to characterize the passing patterns that support collective tactical behaviour in football players of different ages (U15, U17, and U19) in different field zones. Two hundred and twenty-eight male players, divided into U15, U17, and U19, participated in the study. Cluster analysis was used to group the passes into three sizes (short, medium, and long). The chi-square test was used to analyse the effect of player age on game-passing patterns in each field zone. The results revealed that long and medium passes were used more in areas close to the goals and short passes in the middle area of the field, concerning all ages (p < 0.001). Furthermore, the analysis of the relative distance between the ball carrier and the receiver indicated that older players (U17 and U19) used more distant players to pass the ball in medium and long passes. These results can help coaches design small-sided games according to the players' ages and adjust to the field's space and the numerical relationship, thus creating a greater transfer from training to competition.

Intraindividual Relationships Between Training Loads and Heart-Rate Variability in High-Level Female Futsal Players: A Longitudinal Study.

PURPOSE: To investigate the internal training loads of a professional Spanish female futsal team throughout 26 weeks of training including preseason and in-season weeks and verify the impact of training period and/or training load magnitudes on heart-rate variability responses. Furthermore, we aimed to assess, intraindividually, the relationship between training load and the coefficient of variation (CV) of weekly natural log of the root mean square difference of successive normal interbeat (RR) intervals (lnRMSSDCV), obtained from ∼5 measures per week, and recorded in the seated position. METHODS: A within-subject design involved 12 high-level outfield female futsal players (mean [SD] age: 23.9 [3.4] y). RESULTS: lnRMSSD was significantly lower and lnRMSSDCV was significantly higher during the preseason (weeks 1-6) compared to in-season (weeks 7-26) (P < .001). Individually, players presented moderate to large negative correlations between lnRMSSDCV and lnRMSSD during the 26 weeks of observation. Correlations ranged between rplayer4 = -.41 (95% CI, -.69 to -.02) and rplayer12 = -.55 (-.78 to -.18). Players also presented moderate to very large positive correlations between lnRMSSDCV and session rating of perceived exertion. Correlations ranged between rplayer7 = .41 (.04 to .71) and rplayer1 = .71 (.45 to .86). CONCLUSION: Professional female futsal players in this study presented increased lnRMSSD and reduced lnRMSSDCV during 20 weeks into the competitive season compared to 6 weeks of preseason. Furthermore, lnRMSSDCV was negatively associated with lnRMSSD on an intraindividual basis. Finally, higher internal training loads were positively correlated with lnRMSSDCV, indicating that heart-rate variability is responsive to weekly training loads.

Intensity demands and peak performance of elite soccer referees during match play.

OBJECTIVES: This study examined the peak physical and physiological (heart rate) performance intensities andassociated decrements in elite soccer referees during match play. DESIGN: Longitudinal study. METHODS: Physical performancevariables and heart rate were analyzed during 457 matches across two seasons. Differences between halves, and the rate ofdecline in peak performance intensities across moving average durations of 1-10 minutes were assessed using linear mixed models and power-law analysis, respectively. RESULTS: Large significant differences were observed between halves for mean total distance, mean velocity, mean heart rate, and percentage of maximal heart rate (p ≤ 0.05; r = 0.51-0.64). Peak intensities (p ≤ 0.05; r = 0.15-0.17) and the rate of decline (p < 0.001; r = 0.17-0.37) were significantly higher in the 2nd half compared to the 1st half, for relative total distance, relative high-intensity running and mean velocity. The rate of decline was significantly greater in the 2nd half than the 1st half for relative distance covered by high-intensity acceleration (>2 m/s-2/min), deceleration (<-2 m/s-2/min), and relative mean heart rate (p < 0.001; r = 0.28-0.61). Elite soccer referees might have experienced transient fatigue during match play, as relative high-intensity running immediately following the most intense 5-minute period significantly declined by 61.2% ( p< 0.001; r = 0.94), and was 16.2% lower than the mean 5-minute period (p < 0.001; r = 0.34). CONCLUSIONS: Increased physical and physiological demands during match play, with associated declines in the second half and transient signs of fatigue throughout the match, supports the inclusion of high-intensity interval and endurance training programs to prepare soccer referees for the intensity demands and peak performance outcomes of match play.

The effects of individual and collective variability on youth players' movement behaviours during football small-sided games.

This study aimed to identify the effects of playing with additional individual (IND), collective (COL) or individual-collective (MIX) variability on youth football players' performance during small-sided games. Twelve youth football players (U17, age = 16.1 ± 0.9 years) played a goalkeeper (Gk) + 6 outfield players a-side (Gk+6vs6+Gk) under four conditions: (i) playing in the 1:2:3:1 formation without any other rule (control condition, CTR); (ii) 1:2:3:1 formation with additional body restrictions changing each minute (individual condition, IND); (iii) using different tactical formations modified each minute (collective condition, COL; (iv) using different tactical formations and body restrictions varied each minute (individual-collective condition, MIX). Generally, there were similar behaviours across conditions, especially for the CTR and the MIX. Nevertheless, the CTR condition presented moderate higher values in the lateral direction (p ≤ .05), while also higher longitudinal synchronization compared to the IND (p ≤ .05). The COL condition presented higher spatial exploration (p ≤ .05), which may justify the higher values for distance covered while running and sprinting (p ≤ .05). Overall, coaches may use the IND condition to refine players' technical actions, while the COL condition to develop players' ability to perform in different playing positions and team structures.

How spatial constraints afford successful and unsuccessful penetrative passes in elite association football.

BACKGROUND: The aim of the present study was to examine the spatial relations between teams (macro-level) and groups of players (meso-level) that afford successful penetrative passes (off-ball advantage) in elite football. METHODS: Three balanced home matches from a Premier League team with 91 ball possessions in which a pass was performed into the opposition defensive area and overpassed the first defensive line, promoting a perturbation of the defensive team equilibrium, were selected for analysis. The spatial relations between teams were measured through spatial variables that captured the areas occupied by the teams, while the spatial relations between players were measured through variables that captured the distances and angles between attacking and defending players near the ball. RESULTS: Results revealed, at the macro-level, higher values of width ratio between teams and the width of the attacking team for unsuccessful penetrative passes (UPP), when compared to successful penetrative passes (SPP). At the meso-level, a general decrease in distances and an increase in angles between attacking and defending players were observed between successful to unsuccessful penetrative passes. CONCLUSIONS: These findings highlight the importance of using positional data analysis to identify teams' tactical profiles and to potentiate coaches' interventions.

Strength and Power Performance Changes During an In-Season Resistance Training Program in Elite Futsal Players: A Case Study.

In this study, we aimed to analyze (i) the strength and power changes after resistance training (RT) in elite futsal players, and (ii) the associations between the session rate of perceived exertion (sRPE) and perceived total quality recovery (TQR), and the sRPE and TQR with the volume load of the RT program. Ten elite futsal players (24.8 ± 5.4 years; 76.2 ± 7.1 kg; 1.77 ± 0.05 m) performed an in-season 8-week RT program twice per week. RT consisted of 2-3 sets x 3-6 reps at 45-65% of one-repetition maximum (1RM) with maximal velocities in the full squat and complementary exercises with the same volume. We assessed the TQR before every session, while the sRPE was calculated after each RT session. One week before and after the intervention, we measured the countermovement jump (CMJ) height, isometric hip adduction strength (IHAS), 1RM, and peak power (PP) in the full squat progressive loading test. After the 8-week training program, there was a significant improvement in most outcomes, yet the gains (%Δ) remained below the minimal detectable change (MDC), except for IHAS (CMJ: p < 0.05, %Δ = 6.7, MDC% = 7.2; IHAS: p < 0.001, %Δ = 19.1, MDC% = 14.6; 1RM: p > 0.05, %Δ = 9.2, MDC% = 21.5; PP: p < 0.05; %Δ = 14.4, MDC% = 22.4). We also found a significant negative correlation between TQR and the sRPE (r = -0.45, p < 0.001). Our data suggest that RT based on low-volume and low-to-moderate loads may not produce a sufficient stimulus to induce meaningful dynamic strength and power gains in elite futsal players, although it improves isometric strength. Furthermore, monitoring TQR before sessions may show coaches how the elite futsal player will perceive the session's intensity.

Corrigendum: Impact of victory and defeat on the perceived stress and autonomic regulation of professional eSports athletes.

[This corrects the article DOI: 10.3389/fpsyg.2022.987149.].

Validity and Reliability of The Smart Groin Trainer for Measuring Hip Adduction Strength.

We analyzed the Smart Groin Trainer device's validity and reliability to measure the isometric hip adduction strength during the adductor squeeze strength test. Fifteen professional soccer players (25.33±4.06 years) and fifteen university students (21.60±1.76 years) participated in this study. All participants performed the squeeze strength test using two portable dynamometers: Smart Groin Trainer and Globus Ergometer. Three maximal isometric hip adduction contractions lasting 5s, interspersed by 3min rest intervals, were performed. Reliability was analyzed with intraclass correlation coefficients, standard error of measurements, and minimal detectable change. The absolute percent error and inter-device accuracy were also analyzed. Correlation analysis assessed the inter-device concurrent validity. The results found no significant differences (p>0.05) between devices in the squeeze strength test values in soccer players and university students. Inter-device comparisons revealed excellent levels of reliability and accuracy in soccer players. Concurrent validity measures revealed strong inter-device relationships in soccer players (r=0.89) and very strong relationships in university students (r=0.99). Intra-device analysis using the Smart Groin Trainer showed excellent relative and absolute reliability in tested soccer players. Our data demonstrated excellent levels of agreement between both dynamometers during the squeeze strength test, suggesting the Smart Groin Trainer as a valid, reliable, and accurate device to measure isometric hip adduction strength.

Talent Identification and Development in Male Futsal: A Systematic Review.

This review aimed to identify and synthesize the most significant literature addressing talent identification and development in futsal. A systematic review of Web of Science™ (all databases), Scopus, PubMed and SPORTDiscus databases was performed according to the preferred reporting items for systematic reviews and meta-analyses guidelines. This study included original articles in English, Spanish or Portuguese containing relevant data on talent development/identification of male futsal players. The search yielded 238 articles. After screening, a total of 32 manuscripts were fully reviewed. The quality of the data reviewed was generally good. Results indicate that the most successful players exhibit technical, tactical, anthropometric, physiological and psychological advantages and are distinguished from lower-level players based on their earlier dedication to training. This review highlights the need for those involved in the process of identifying and developing talented futsal players to consider the technical and tactical skills of futsal players, along with their anthropometric and physiological characteristics, scaled to age. Finally, special attention should be paid to the supportive psychosocial environments created in sports academies for developing futsal players. Overall, talent identification and development programmes in futsal need to be dynamic and offer the possibility of changing assessment parameters in the long term.