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.

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 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.

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.

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.

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.

Anodal Transcranial Direct Current Stimulation Reduces Competitive Anxiety and Modulates Heart Rate Variability in an eSports Player

Previous research has recently shown that high cognitive and somatic anxiety and low self-confidence, before and during sport competitions have a significant correlation with heart rate variability (HRV) changes and can reduce overall athletic performance. Therefore, interventions, such as transcranial direct current stimulation (tDCS), can be a potential tool to reduce psychophysiological anxiety-related and enhance athletic performance. We present a case of a male professional athlete of eSports. We explored the effects of a single session of anodal tDCS (a-tDCS) at 2mA over the dosrsolateral prefrontal cortex (DLPFC) on competitive anxiety and HRV assessed in baseline (BL), pre-tDCS, post-tDCS and post-game moments and compared between moments. Here, we found a decrease in somatic and cognitive anxiety, as well as an increase in self-confidence and in SDNN index in the post-tDCS moment compared with BL, pre-tDCS and post-game moments. These findings can be a result of an acute change in the attentional state, influencing the processing of threatening information essential for cognitive anxiety and of a self-regulatory process, which can regulate physiological arousal response, such as HRV.

Body composition and grip strength constraints in elite male rink-hockey players of contrasting ethnicity

Rink hockey is a highly specialized and physiological demanding sport with sparse research regarding the game and athletes’ characteristics. A cross-sectional study was developed to characterize the body composition and grip strength of elite male rink hockey players and to establish the relationship between ethnicity on body composition and grip strength. A sample of 100 elite rink-hockey athletes aged 26.59 ± 6.02 participated in the study, comprised of 69 Caucasian male adults aged 27.58 ± 6.44 years and 31 Black African male adults aged 24.39 ± 4.27. Body composition was assessed by anthropometric measurements. Static grip strength was assessed with an adjustable dynamometer. Multiple regression analysis was applied to understand which variables constraints body fat percentage (BF) and grip strength. Body mass showed an average of 76.36 ± 9.18 kg for 175.80 ± 5.87 cm of height and BF% of 10.82 ± 5.07%. Maximal right grip strength was 50.91 ± 6.26 kg and 50.27 ± 6.23 kg for left grip strength. Four predictors accounted for 70.01% of the variance of BF%: abdominal circumference (p < 0.001), right thigh circumference (p < 0.001), right calf circumference (p = 0.001) and ethnicity (p = 0.016). Three predictors accounted for 13.1% of the variance of right grip strength: ethnicity (p = 0.013), chronological age (p = 0.024) and right distal thigh circumference (p = 0.014). Results suggest that elite rink hockey athletes have a specific anthropometric identity, which at the elite level may lead to reduced body fat and greater handgrip strength. Ethnicity seems to predict body fat and grip strength in elite rink hockey athletes.

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.

Clustering ball possession duration according to players’ role in football small-sided games

This study aimed to explore which offensive variables best discriminate the ball possession duration according to players specific role (defenders, midfielders, attackers) during a Gk+3vs3+Gk football small-sided games. Fifteen under-15 players (age 13.2±1.0 years, playing experience 4.2±1.0 years) were grouped according to their positions (team of defenders, n = 5; team of midfielders, n = 7; team of attackers, n = 3). On each testing day (n = 3), each team performed one bout of 5-min against each team in a random order, accounting for a total of nine bouts in the following scenarios: i) defenders vs midfielders; ii) defenders vs attackers; iii) midfielders vs attackers. Based on video, a notational analysis process allowed to capture individual and collective actions. According to each playing position group, discriminant analysis was used to identify relevant variables that discriminate different ball possession sequences (short, medium, and long). The analysis revealed the existence of three clusters according to ball possession duration, classified as short sequence (~4 seconds), medium sequence (~10 seconds) and long sequence (~18 seconds). The number of touches per possession was the variable that discriminates the ball possession duration from all playing positions while passing actions were related to midfielders and attackers. In addition, different ball possessions sequences in the attackers were also discriminated by the number of players involved per possession. Accordingly, to increase the duration of the offensive phase during small-sided games, coaches should foster the players’ ability to stay on the ball, as it may amplify their opportunities to maintain the ball possession. In addition, coaches may also include reward rules to encourage midfielders and attackers’ passing actions and the number of attackers involved during the attack to promote longer ball possessions durations.

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

Competitive sports involve physiological, technical and psychological skills, which influence directly on individuals’ performance. This study aims to investigate the levels of perceived stress and Heart Rate Variability (HRV) before and after matches with victory and defeat in professional eSports athletes. Our hypothesis was that the winners would have better autonomic and stress responses after match, thus corroborating the literature on neurocardiac connections. Fifty male eSport players were selected players from 10 different Brazilian teams. The experiment was carried out in 2 sessions. Firstly, after signing the informed consent form, 24 h before the game, anthropometric, physical activity levels and time of expertise data were recorded only for sample characterization and the players were familiarized with the perceived stress scale—10 (PSS-10) and the HRV measurements. Secondly, players performed the PSS-10 and HRV recording at rest by 10 min 60 and 30 min before the game (i.e., baseline time) and 10 min after the end of the game. Overall, concerning PSS-10 our findings show that VG had significant reduced scores in post-game time compared to baseline (BL) and pre-game times, while DG had significant increased scores in post-game time compared to BL and pre-game times. Regarding HRV, our results demonstrate that VG had significant increase in RR, SDNN, rMSSD, pNN50 and HF, and significant decrease in LF and LF/HF, while DG had a significant decrease in RR, SDNN, rMSSD and HF, and significant increase in LF and LF/HF. It was observed that VG had better HRV responses (greater parasympathetic activation) as well as lower levels of perceived stress, while DG had worst HRV responses (greater sympathetic activation) and higher levels of perceived stress.

Amplifying the effects of adding extra players during association football game-based scenarios

This study aimed to compare under-18 association football players’ performance (age = 17.7±1.0 years; playing experience = 9.0 ± 3.2 years) when manipulating the number of teammates and opponents during football game-based practices. Time-motion, individual and tactical-related variables were monitored when manipulating conditions with different number of teammates and opponents (11vs11, No-Sup, No-Inf; 11vs12, Low-Sup, Low-Inf; 11vs13, Mod-Sup, Mod-Inf; and 11vs14, High-Sup, High-Inf). Results showed that adding teammates promoted increases in the longitudinal synchronization from No-Sup to Mod-Sup (Cohen’s d with 95% of confidence intervals: 0.25 [0.12; 0.39]; p < .001) and High-Sup (0.61 [0.41; 0.82]; p < .001), while decreases in the distance to the nearest teammate, both in the offensive and defensive phases (p < .001 and p = .005, respectively). In addition, it was observed lower distance covered while running when playing in High-Sup compared to No-Sup (0.30 [-0.01; 0.61]; p = .002) during the defensive phase. Attacking in numerical inferiority promoted a higher variability in the distance to the nearest teammate from No-Inf to High-Inf (0.83 [0.27; 1.38]; p = .044), while decreasing the physical demands, specifically distance covered while running (-0.49 [-0.99; 0.01]; p = .039). In turn, defending, mainly in high-inferiority, increased the total distance covered compared to No-Inf (0.61 [0.30; 0.91]; p < .001) and led to a decrease in the distance to the nearest teammate (-0.90 [-1.35; -0.44]; p = .002). Overall, coaches may manipulate the number of teammates and opponents to promote distinct effects at the level of cooperation and opposition dynamical interactions.

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.

Capturing and Quantifying Tactical Behaviors in Small-Sided and Conditioned Games in Soccer: A Systematic Review

Purpose: To systematically describe and analyze the tracking systems, the variables, and the statistical methods used to evaluate the players and teams' tactical behavior in small-sided and conditioned games (SSCGs). Methods: A search was done in Web of Science, PubMed, Science Direct, and Scielo databases to identify manuscripts published between 2008 and 2019 that manipulated small-sided and conditioned games (SSCGs) and analyzed tactical behaviors of players and teams. Results: From 349 articles identified, 31 were selected for review. To collect positional data, the global positioning system (GPS), the local position measurement (LPM) system, and TACTO were identified as reliable tracking systems. Twenty-one positional variables were identified to evaluate tactical behaviors, grouped into five main categories: team balance, playing space, width and length of playing space, and interpersonal distance. Tactical behavior patterns were analyzed using approximate entropy, sample entropy, Shannon entropy, and patterns of coordination between players and teams were analyzed using relative phase and running correlation. Discussion: The tracking systems analyzed were reliable but revealed different advantages and disadvantages of their use. Authors should define the use of each tracking system based on their purpose and level of precision required for analysis. A great duplication was observed on the variables used with similar purposes of tactical analysis. The identification of the variables according to their purpose of analysis will allow a better understanding of their use in the future.

Amplifying perceptual demands: How changes in the colour vests affect youth players performance during medium-sided games

This study explored how manipulating the colour of training vests affects footballers' individual and collective performance during a Gk+6vs6+Gk medium-sided game. A total of 21 under-17 years old players were involved in three experimental conditions in a random order for a total of four days: i) CONTROL, two teams using two different colour vests; ii) SAME, both teams wearing blue vests; iii) MIXED, all 6 players per team wore different colour vests. Players' positional data was used to compute time-motion and tactical-related variables, while video analysis was used to collect technical variables. Further, these variables were synchronized with spatiotemporal data allowing to capture ball-related actions in a horizontal 2D plan. All variables were analysed from the offensive and defensive perspective. From the offensive perspective, players performed more and further shots to goal during the CONTROL than in SAME and MIXED (small effects) conditions, with a decreased distance to the nearest defender (small effects). While defending, results revealed lower distance to the nearest teammate (small effects) in the CONTROL than in the SAME and MIXED conditions, and higher team longitudinal synchronization (small effects). In addition, the CONTROL showed in general lower values of team width while defending than in the other 2 conditions. Overall, coaches may use the CONTROL condition to emphasize offensive performance and defensive behaviour over the longitudinal direction with increased physical demands. In turn, coaches may use the manipulation of players vests to emphasize defensive performance, as players seem to behave more cohesively under such scenarios.

Construction and validation of an observation tool of the imbalance pass in futsal

Abstract This study aimed to construct a tool for observing the imbalance pass in futsal through Microsoft Excel® software and to establish its content validity and intra- and interobserver reliability based on the calculation of the content validity coefficient (CVC) and the intraclass correlation coefficient (ICC). For the construction of the tool, futsal specialists (n = 10) with an average age of 44.1 ± 12.34 years and 19 ± 7.21 years of experience in the field participated in the study. 60% of the specialists have international-level expertise and 50% are active in practice and in academic field (higher education professor). According to the methodology, 23 items were proposed to assess the imbalance pass in futsal. CVC was calculated based on language clarity, practical pertinence and theoretical relevance for each item of the instrument and for the instrument as a whole; ICC was calculated based on intra- and interobserver agreement. Language clarity, practical pertinence and theoretical relevance revealed a result of 0.92, 0.93 and 0.95, respectively, and the values for intra- and interobserver agreement reliability were excellent according to the literature (> 0.75). Thus, it is concluded that the items proposed in the tool obtained satisfactory psychometric properties.

Career Planning in Elite Soccer: The Mediating Role of Self-Efficacy, Career Goals, and Athletic Identity

This study proposed a model to examine the role of self-efficacy, career goals, and athletic identity (AI) on the career planning of elite soccer players. Two hundred and eighty-one elite soccer players (males) participated in this study. Means, SD, and bivariate correlations were calculated for the variables under analysis. The hypothesized effect of self-efficacy, career goals, and AI on career planning was tested using structural equation modeling (SEM). Results supported the adequacy of the proposed model in explaining the career planning. Career planning is positively influenced by the level of self-efficacy of players through the definition of career goals and is negatively influenced by the level of AI. At the same time, the self-efficacy of players through the definition of career goals positively influenced AI. These findings reinforce the important role of self-efficacy and career goals for the development of AI and career planning and at the same time the opposite relationship between AI and career planning. Thus, it is suggested that a balance on AI, maintaining high levels of self-efficacy and career goals, is required to improve the process of career planning and retirement.

How the Number of Players and Floaters' Positioning Changes the Offensive Performance during Futsal Small-Sided and Conditioned Games

This study aims to analyse the effects of floater positioning within futsal Gk + 3vs3 + Gk and Gk + 2vs2 + Gk small-sided and conditioned games (SSCG) on youth offensive performance on an action per minute per player basis. Three experimental conditions were carried out through the manipulation of floater positioning: floaters off (FO), final line floaters (FLF) and lateral floaters (LF). Thirty male futsal players (U19 age category) participated in the study and played once within each situation in a random order on different days. Offensive performance based on "action per minute per player" was analysed through indirect and external systematic observation. Results showed significant differences between both SSCGs (2vs2 and 3vs3). Specifically, according to the game principles analysed, 3vs3 is associated with higher values of passing and dribbling action to progress towards the goal without beating a defensive line (moderate to large effect size), while 2vs2 is associated with higher values of passing and dribbling actions that beating a defensive line (moderate to very large effect size). In addition, 2vs2 is associated with dribbling and shooting actions to shoot at goal with the lowest level of opposition (moderate effect size). Indeed, whilst the 2vs2 game format seems to promote more 1vs1 situations, the 3vs3 game format encourages more ball possession and collective tactical behaviours. Thus, training tasks intended to improve dribbling and shooting actions should use a smaller number of players whereas tasks intended to improve passing actions for ball possession should include a higher number of players with or without floaters. It seems that the number of players can influence the tactical behaviour of the team. These findings should be considered for the design of futsal training tasks, according to the main objective of the training session. For example, if the coach aims to promote the number of dribbles and shots within a SSCG, 2vs2 SSCG situations should be prioritised.

Effects of Different Recovery Times on Internal and External Load During Small-Sided Games in Soccer

BACKGROUND

The ability to maintain a high intensity of exercise over several repetitions depends on recovery from previous exercises. This study aimed to identify the effects of different recovery times on internal and external load during small-sided soccer games.

HYPOTHESIS

An increase in recovery time will increase the external training load and decrease the internal exercise load, which will result in a greater physical impact of the exercise.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 2.

METHODS

Twenty male semiprofessional soccer players participated in the present study. They performed the same exercise (5-a-side game format) continuously (1 × 18 minutes) and repeatedly/fractionated (3 × 6 minutes) with different recovery times (30 seconds, 1 minute, 1.5 minutes, and 2 minutes). Their internal load (ie, average heart rate (HR) and maximum HR) and external load (ie, total distance, maximum speed, and ratio meters) were measured using an HR band and an inertial device equipped with a global positioning system, respectively.

RESULTS

The manipulation of recovery times induced differences in the internal and external load. For the same total duration, the external and internal load indicators exhibited higher values during the fractionated method, particularly with short recovery periods.

CONCLUSION

The application of small-sided soccer games with different recovery times induced varying responses in training load. To maintain high physical performance and high training load, the fractional method with short recovery periods (ie, 30 seconds) should be used. In contrast, to carefully manage players' efforts and decrease response to training load, continuous or fractional methods with longer recovery periods (ie, 1-2 minutes) should be used.

CLINICAL RELEVANCE

The proper prescription of recovery time between exercises facilitates enhanced training efficiency and optimized performance.

How Informational Constraints for Decision-Making on Passing, Dribbling and Shooting Change With the Manipulation of Small-Sided Games Changes in Futsal

In this study, we explored how manipulating floaters' positions in small-sided futsal games (SSGs) promote changes in the informational constraints that support decision-making (DM) for passing, dribbling and shooting tactics. We made changes in four experimental 3 vs 3 small-sided game conditions with 30 male futsal players (U19 age category): (a) Floaters Off (FO), (b) Final Line Floaters (FLF), (c) Lateral Floaters own field sideline (LFofsl) and (d) Lateral Floaters full field sideline (LFffsl). We assessed players' activity with WIMU PRO™ software during the SSGs, using the Game Performance Evaluation Tool (GPET) to analyze a total of 1,635 decisions. DM for dribbling was generally based on the interpersonal distance between the ball carrier and direct opponent, considering the defensive team length and the offensive team area. Shooting decisions were constrained, by certain attacking-defending teams' spatial-temporal relations with regard to playing space and team balance as affected by manipulating floaters' positions. The coaches' decisions to change the floaters' positions during SSGs may change informational variables sustaining the dribbling decision, but no changes in SSG variables affected passing DM.

Could tDCS Be a Potential Performance-Enhancing Tool for Acute Neurocognitive Modulation in eSports? A Perspective Review

Competitive sports involve physical and cognitive skills. In traditional sports, there is a greater dependence on the development and performance of both motor and cognitive skills, unlike electronic sports (eSports), which depend much more on neurocognitive skills for success. However, little is known about neurocognitive functions and effective strategies designed to develop and optimize neurocognitive performance in eSports athletes. One such strategy is transcranial direct current stimulation (tDCS), characterized as a weak electric current applied on the scalp to induce prolonged changes in cortical excitability. Therefore, our objective is to propose anodal (a)-tDCS as a performance-enhancing tool for neurocognitive functions in eSports. In this manuscript, we discussed the neurocognitive processes that underlie exceptionally skilled performances in eSports and how tDCS could be used for acute modulation of these processes in eSports. Based on the results from tDCS studies in healthy people, professional athletes, and video game players, it seems that tDCS is applied over the left dorsolateral prefrontal cortex (DLPFC) as a potential performance-enhancing tool for neurocognition in eSports.

The Co-Occurrence of Satisfaction and Frustration of Basic Psychological Needs and Its Relationship with Exercisers' Motivation

Although the relationship between both need frustration and, particularly, need satisfaction and different motivational regulations for exercise has been widely examined in the literature, little is known about the co-occurrence of both need satisfaction and need frustration in the exercise context. Grounded in self-determination theory, the present study aimed to examine the effects of both need satisfaction and frustration on motivational regulations for exercise, by applying a response surface analysis approach. In total, 477 regular exercisers aged 18-54 years participated in this study. The interaction between needs (high on both need satisfaction and frustration) displayed a positive and significant association with amotivation, integrated regulation, and intrinsic motivation. Considering the direction of the discrepancy (high vs. low levels of need satisfaction and frustration) related to the behavioral regulations, results showed that higher need satisfaction relative to need frustration was associated with more self-determined regulations of motivation. Contrarily, higher need satisfaction relative to need frustration was associated with lower scores on amotivation, external, introjected, and identified regulation. Overall, these findings extend previous literature, suggesting that need satisfaction and frustration are distinct factors that can be experienced simultaneously in individuals during exercise and that different degrees of both needs have different associations with behavioral regulations.

Heart Rate Variability Changes From Traditional vs. Ultra-Short-Term Recordings in Relation to Preseason Training Load and Performance in Futsal Players

Nakamura, FY, Antunes, P, Nunes, C, Costa, JA, Esco, MR, and Travassos, B. Heart rate variability changes from traditional vs. ultra-short-term recordings in relation to preseason training load and performance in futsal players. J Strength Cond Res 34(10): 2974-2981, 2020-The aims of this study were to analyze heart rate variability (HRV) changes in futsal players during preseason training using both "criterion" (10-minute) and ultra-shortened (2-minute) measures, and to determine whether they were related to changes in the Yo-Yo Intermittent Recovery Test, level 1 (Yo-Yo IR1) performance and accumulated training load (TL). Eleven male competitive futsal players (age = 25.19 ± 4.70 years; body mass = 73.15 ± 11.70 kg; and height = 176.90 ± 5.01 cm) volunteered for the study. Data collection took place during the first to the fourth weeks of preseason training. Training load was monitored with session ratings of perceived exertion. The total distance (TD) covered during the Yo-Yo IR1 was recorded during week 1 and week 4. Heart rate variability was measured through the log-transformed root mean square of successive normal-to-normal interval differences using the ultra-short analysis, with its weekly mean (lnRMSSDM) and coefficient of variation (lnRMSSDCV) recorded, and by means of the criterion method (weeks 1 and 4). lnRMSSDM was likely higher at week 4 compared with week 1 using both criterion and ultra-short recordings. Moderate-to-large correlations were found between changes in the lnRMSSDM and lnRMSSDCV values and changes in TL and TD (r values ranged from -0.48 to 0.65). Changes in ultra-short HRV measures (i.e., increase in lnRMSSDM and decrease in lnRMSSDCV) during futsal preseason were associated with increased performance. The players who accumulated higher perceived TLs displayed smaller improvements in the Yo-Yo IR1 performance and HRV.

Pre-match Warm-Up Dynamics and Workload in Elite Futsal

Warming up prior to competition is a widely accepted strategy to increase players’ readiness and achieve high performances. However, pre-match routines are commonly based on empirical knowledge and strongly influenced by models emerging from elite team practices. The aim of the present study was to identify and analyze current pre-match warm-up practices in elite futsal. Forty-three elite players were analyzed during their pre-match warm-up routines during the Portuguese Futsal Cup Final 8. Warm-up tasks were classified according to duration, type of activity, sequence, and structure. External load variables included the total distance covered, total distance covered per minute, running distance per minute, sprinting distance per minute, number of accelerations per minute, and number of decelerations per minute. Results highlighted that warm-up routines lasted for 27.5 ± 9.2 min and included nine major different tasks. Open-skill activities were prioritized by coaches; competitive and non-competitive futsal-specific tasks were included in 90% of the total warm-up routines, with higher focus on non-competitive tasks (68% of total time). The intensity progressively increased during warm-ups, mainly because of the higher number of accelerations and decelerations per minute. Pre-match warm-up routines strongly endorse futsal-specific and representative tasks in order to establish pre-match settings able to prepare players for the upcoming game. When designing pre-match warm-up routines, coaches should be aware that duration, sequence, and type of tasks may affect players’ acute performance and readiness.

Exploring the Effects of Playing Formations on Tactical Behavior and External Workload During Football Small-Sided Games

Baptista, J, Travassos, B, Gonçalves, B, Mourão, P, Viana, JL, and Sampaio, J. Exploring the effects of playing formations on tactical behavior and external workload during football small-sided games. J Strength Cond Res 34(7): 2024-2030, 2020-This study aimed to identify the effects of playing formations on tactical behavior and external workload during football small-sided games. Twenty-three semiprofessional footballers integrated 3 different playing formations in a 7-a-side small-sided game, according to their specific player positions: team 4:3:0 (4 defenders and 3 midfielders); team 4:1:2 (4 defenders, 1 midfielder, and 2 forwards); and team 0:4:3 (4 midfielders and 3 forwards). Based on players' movement trajectories, the following individual and collective tactical variables were calculated: total distance covered and distance covered while walking, jogging, running, and sprinting, distance from each player to both own-team centroid and opponent-team centroid, individual area, team length, team width, and surface area. Approximate entropy was computed to identify the regularity of each variable. The team 4:3:0 promoted players' space exploration with moderate physical efforts. The team 4:1:2 promoted compactness and regularity of the team with increase in the physical efforts. The team 0:4:3 promoted team balance and adaptability on space coverage with increase in physical efforts. Concluding, different playing formations support different game dynamics, and variations on external load were directly linked with the variations on tactical behavior. The analysis of tactical behavior through quantification of variability of patterns of play and quantification of distance covered at different velocities were the most useful information for the analysis of the effects of practice task manipulations. Therefore, in a practical sense, strength and conditioning coaches should plan and monitor these tasks in interaction with the head coaches.

Can Tracking Data Help in Assessing Interpersonal Contact Exposure in Team Sports during the COVID-19 Pandemic?

During the COVID-19 pandemic, the temporary closure of physical activity and sports facilities, and the generalized cancellation or postponement of sports events have a massive impact on social and economic development. In this study, we explored the feasibility of using tracking data from a football match to assess interpersonal contact between individuals by calculating two measures of respiratory exposure. The dynamic tracking positioning of all players and referees during one international football match was analyzed. For each individual, two measures of respiratory exposure were calculated, based on the 2 m interpersonal distance recommendations for contact tracing for COVID-19 control. Overall, individuals spent a median of 0.12 mm:ss (IQR = 0.45 mm:ss) exposed to interpersonal contact of fewer than 2 m from others. The highest value of exposure was observed between two players of opposing teams (6.35 mm:ss). The results suggest that tracking data can be used to assess respiratory exposure to interpersonal contact in team sports, such as football. The measures of exposure calculated can be used to the prompt identification of high-risk contacts of COVID-19 cases during a match or a training session, but also the risk stratification of different sports and physical activities.

Development of Defensive Actions in Small-Sided and Conditioned Games With Offensive Purposes in Futsal

Based on ecological dynamics approach, non-linear pedagogy (NLP) have emerged with the goal of promoting a holistic approach through the use of small-sided and conditioned games (SSCGs), to optimize specific tactical defensive and offensive behaviors of players. This study analyzed the indirect effects of an intervention program, based on NLP (task design based on tactical principles of attack and numerical advantage of attacking team), in decision-making (DM) and execution (Ex) in defensive technical–tactical actions in U16 futsal. Eight futsal players (U16 years) participated in 12 training sessions, spread over two phases: preintervention and intervention. The Game Performance Evaluation Tool (GPET) instrument was used to analyze the DM and Ex of 2,600 defensive actions measured during competitive matches. Results showed significant improvements in marking actions (to the player with the ball: DM, p = 0.001; Ex, p = 0.001; and to the player without the ball: DM, p = 0.039; Ex, p = 0.046), improvements in blocking actions (DM, p = 0.015), and improvements in help-coverage actions (Ex, p = 0.014). No significant differences were found in the interception and tackling actions. This study has shown evidence that the NLP approach is an appropriate theoretical framework to enhance acquisition of defensive tactical behavior in futsal. However, not all actions improved. Therefore, coaches should design representative tasks to optimally develop technical–tactical training processes based on the phases of futsal game (offensive and defensive) and considering the level of opposition.

Activity Profile and Physical Performance of Match Play in Elite Futsal Players

Understanding the physical demands of futsal requires a precise quantification of the players’ activities during match play. This study aimed to (1) describe external load, identifying the differences between the first and second halves in official futsal matches; (2) identify the most important external workload metrics to profile the players; and (3) identify the collinearity between variables in the analysis of physical performance of futsal players. Match external load data were collected from male players (n = 28) in six games of the Final Eight of the Portuguese Futsal Cup 2018. The players increased the distance covered per minute at 12–18 km/h in the second half (p < 0.01). Dynamic stress load also increased in the second half (p = 0.01). The variables that best predicted the physical profile of each player were decelerations (predictor importance, PI = 1), walking (PI = 1), sprinting (PI = 1), jogging (PI = 0.997), total distance covered per minute (PI = 0.992), and metabolic power (PI = 0.989). Decelerations showed the highest association with the clusters levels (p < 0.001; PI = 1); this suggests decelerations as a potential candidate for best analyzing the physical load of futsal players. Overall, the data from this exploratory study suggest that distance covered per minute (m/min), number of sprints (>18 km/h), decelerations (greater than-2 m/s), and metabolic power (W/kg) are the variables that most discriminate the load intensity of elite futsal players.

How Numerical Unbalance Constraints Physical and Tactical Individual Demands of Ball Possession Small-Sided Soccer Games

This study aimed to explore the effects of playing different unbalanced ball possession small-sided games on external workload (distance covered while walking, running, and sprinting, and max speed), tactical individual actions (number of passes with dominant and non-dominant foot), and internal load (rating of perceived exertion, RPE) in under-23 soccer players. Participants played 4v2, 4v3, 4v4, 4v5, and 4v6 small-sided games (SSGs) on a 30 × 25 m playing area. Data were analyzed under an opponent-based perspective, by fixing one team (4vX), and by cooperation-based perspective according to teammates (4v2+X). Global Position System (GPS) monitors were used to collect and compute external workloads and individual tactical actions, and Borg Scale CR10 was used to evaluate RPE. High-Superiority (4v2), Superiority (4v3), and Very Low-Cooperation (4v2+0) formats allow players in balanced teams to cover more distance while walking; on the other side, Inferiority (4v5), High-Inferiority (4v6), and Very High-Cooperation (4v2+4) allow players to sprint more and practice more tactical individual actions as a resultant emergent behavior; all players in SSG conditions with a lower number of conditions, perceived the exercise as more intense, especially in situations with less than two players. Overall, playing in high inferiority situations (4v2 and 4v6) may be used to increase physical demand for the outnumbered team, while coaches may use low superiority situations to adjust the task complexity when developing the players’ tactical individual actions.

A Review of Players' Characterization and Game Performance on Male Rink-Hockey

The aim of this study was to review the evolutionary tendencies of research regarding to the study of male Rink-Hockey players´ and game performance. A systematic search was conducted in PubMed, Web of Knowledge and Scopus databases according to PRISMA method. The initial search identified 815 titles, resulting in 19 articles being included within the review. Original papers (English language) contained relevant data regarding rink hockey players' performance or morphological/physiological demands, anthropometry/body composition characteristics were eligible. Studies were classified into categories: (1) Physiological Demands, (2) Anthropometry and Body Composition, (3) Game Characterization/Patterns, (4) Injuries. Results indicated that Rink hockey requires high intensity effort which demands both short and long duration efforts requirements from players. Body composition analysis shows to be an important monitoring tool which complements the understanding of the athlete's cardiac adaptation. Game patterns shows a combination of specific game momentums with different outcomes according to the game zone. The intense short-term movements, collision and contact between players, in addition to the weight and speed of the hard ball and the stick, can considerably increase the risk of moderate and severe injuries. Lack of literature in Rink-Hockey is remarkable, and research is mainly focused on children and adolescents' players. Furthermore, the existing research with adult elite athletes was assessed with a small sample size.

Effects of Knowing the Task's Duration on Soccer Players' Positioning and Pacing Behaviour During Small-Sided Games

The study aimed to identify how the manipulation of knowledge regarding a training task duration constrains the pacing and tactical behaviour of soccer players when playing small-sided games (SSG). Twenty professional and experienced soccer players participated in a cross-sectional field study using three conditions: not informed on the duration of the SSG, which ended after 20 min (Unknown Condition); briefed about playing the SSG for 10 min, but after they completed the 10-min game, they were requested to complete another 10 min (Partial Condition) and informed before that they would play for 20 min (Known Condition). A global positioning system was used to measure the total distance covered and distances of different exercise training zones (walking to sprinting) and to access the dynamic players positioning through the distance from each player to all the teammates and opponents. Additionally, approximate entropy was measured to identify the regularity pattern of each gathered individual variable. The results indicate that the first 10 min of each scenario presented a higher physical impact independently of the initial information. During this time, the tactical behaviour also revealed higher variability. An increase in the distance of the teammates during the second period of 10-min for the Known scenario was also found, which may result from a lower pacing strategy. This study showed that the prior knowledge of the task duration led to different physical and tactical behaviours of the players. Furthermore, the relationship between the physical impact and the regularity of team game patterns should be well analysed by the coach, because the physical impact may be harmful to the development of the collective organization of the team.

How manipulation of playing area dimensions in ball possession games constrains physical effort and technical actions in under-11, under-15 and under-23 soccer players

The aim of this study was to investigate the effects of playing area manipulation (20 × 15 m, 25 × 20 m and 30 × 25 m) on external workloads (total distance covered, distance covered while walking, running and sprinting, number of sprints, maximum sprint speed), internal load perceptions (rating of perceived exertion) and technical actions of passing (number of passes with dominant and non-dominant foot, and maximum passing speed) during 4v4 ball possession small-sided and conditioned games in under-11, under-15 and under-23 soccer players. Results showed higher values in the large playing area for under-11 in the distance covered in different speed zones, sprint number and RPE (all p <.001) for under-15 in sprints number (p <.01) and maximum sprint speed (p =.02), and for under-23 in both RPE and sprint numbers (p <.01). Although no significant differences were found on technical actions, it was still possible to notice some effects through pairwise comparison. High-intensity running was promoted on larger playing areas, where under-11 s were also able to perform more technical actions of passing. Opposite, under-23s were able to perform more passing on smaller playing areas, where under-11 s perceived the exercise more intense. The impact of different playing areas was reduced for the under-15.

Monitoring Workloads of a Professional Female Futsal Team over a Season: A Case Study

The aims of this study were to describe the external and internal workloads in a professional female futsal team during a whole season and to compare workloads during different periods of the season. Ten professional female futsal players (age 22.8 ± 4.3 years; 5.1 ± 2.4 years of experience; weight 61.9 ± 7.1 kg; height 1.66 ± 0.06 m) participated voluntarily in this study during the whole season. The internal workload was measured by the session-Rate of perceived exertion (session-RPE) method, while the external workload was indirectly measured by considering the training and match volume and the type of contents of each session over 43 weeks. Mean sRPE throughout the season was 319.9 ± 127.1 arbitrary units (AU). Higher internal loads (total weekly training load and strain) were reported during the pre-season compared with the in-season mesocycles (p < 0.05); meanwhile, the fifth to eighth mesocycles of the in-season showed an oscillatory pattern. Finally, Monday was the most-demanding session during the in-season period over the Thursday (p < 0.05; effect size: 1.33) followed by match day, meanwhile no statistical differences were reported during different sessions of the pre-season microcycle (p > 0.05). This study suggests that microcycles of pre-season present a stable load pattern, meanwhile workloads during the in-season period report a tapering strategy in a professional female futsal team.

Different Marks in the Pitch Constraint Youth Players' Performances During Football Small-sided Games

Purpose: This study aimed to compare players' performances when manipulating the external markings of the pitch during football small-sided games. Methods: Ten under-15 players performed a 5-a-side (plus goalkeepers) under three conditions: (i) Lines, the game was played in a pitch in which the external boundaries were painted with full lines; (ii) Dashed, the game was played in a pitch in which the external boundaries were painted with dashed lines; (iii) Corners, the game was played in a pitch were the external boundaries were delimited by one marker at each pitch corner. Players' positional data was used to compute tactical and time-motion variables. Also, technical analysis was comprised using video footage. Results: Results showed similar tactical, physical and technical performances between the Lines and Dashed conditions. In contrast, the Lines condition showed small higher effects than Corners scenario in the time spent synchronized in longitudinal and lateral displacements, game pace, total distance covered, distance covered while jogging, number successful dribbles and shots on target. The Lines scenario has also revealed a lower effective playing space, distance covered at walking and running and a lower number of passes (small effects) compared to Corners. Conclusions: These results highlight that these changes in informational perception constraints modify players movement behavior. Accordingly, pitches with more visible boundaries were likely to decrease team dispersion, which may optimize team synchrony and technical performances, while decreasing the distance covered at higher speeds. Coaches may use this information to modify the types of pitch external boundaries markings, exposing the players to different environmental information.

How Does the Adjustment of Training Task Difficulty Level Influence Tactical Behavior in Soccer?

Purpose: This study aimed to investigate if player tactical skill level and age category influence team performance and player exploratory behavior in tasks with different difficulty levels. Method: In total, 48 youth male soccer players participated in the study (U15, n = 24, mean age = 13.06 ± 1.53 years; U17, n = 24, mean age = 16.89 ± 0.11 years). Player tactical skills were evaluated through the System of Tactical Assessment in Soccer (FUT-SAT), allowing them to be organized into three groups according to tactical efficiency: Higher tactical skill level (Group 01), Intermediate tactical skill level (Group 02), and Lower tactical skill level (Group 03). Next, Group 01 and Group 03 of both categories performed six Small-Sided and Conditioned Games (SSCG) each, namely three High difficulty SSCGs and three Low difficulty SSCGs. Team performance and players' exploratory behavior were analyzed through the Offensive Sequences Characterization System and Lag Sequential Analysis, respectively. Results: We found that team performance and players' exploratory behavior were influenced both by the age and tactical skill level of the players, as well as by task difficulty level. Conclusion: Therefore, in an attempt to improve player performance, practitioners must carefully manipulate key task constraints to adapt training task difficulty levels to player age and tactical skill level.

Extracting spatial-temporal features that describe a team match demands when considering the effects of the quality of opposition in elite football

Spatiotemporal patterns of play can be extracted from competitive environments to design representative training tasks and underlying processes that sustain performance outcomes. To support this statement, the aims of this study were: (i) describe the collective behavioural patterns that relies upon the use of player positioning in interaction with teammates, opponents and ball positioning; (ii) and define the underlying structure among the variables through application of a factorial analysis. The sample comprised a total of 1,413 ball possession sequences, obtained from twelve elite football matches from one team (the team ended the season in the top-5 position). The dynamic position of the players (from both competing teams), as well as the ball, were captured and transformed to two-dimensional coordinates. Data included the ball possession sequences from six matches played against top opponents (TOP, the three teams classified in the first 3 places at the end of the season) and six matches against bottom opponents (BOTTOM, the three teams classified in the last 3 at the end of the season). The variables calculated for each ball possession were the following: ball position; team space in possession; game space (comprising the outfield players of both teams); position and space at the end of ball possession. Statistical comparisons were carried with magnitude-based decisions and null-hypothesis analysis and factor analysis to define the underlying structure among variables according to the considered contexts. Results showed that playing against TOP opponents, there was ~38 meters game length per ~43 meters game width with 12% of coefficient of variation (%). Ball possessions lasted for ~28 seconds and tended to end at ~83m of pitch length. Against BOTTOM opponents, a decrease in the game length with an increase in game width and in the deepest location was observed in comparison with playing against TOP opponents. The duration of ball possession increased considerable (~37 seconds), and the ball speed entropy was higher, suggesting lower levels of regularity in comparison with TOP opponents. The BOTTOM teams revealed a small EPS. The Principal Component Analysis showed a strong association of the ball speed, entropy of the ball speed and the coefficient of variation (%) of the ball speed. The EPS of the team in possession was well correlated with the game space, especially the game width facing TOP opponents. Against BOTTOM opponents, there was a strong association of ball possession duration, game width, distance covered by the ball, and length/width ratio of the ball movement. The overall approach carried out in this study may serve as the starting point to elaborate normative models of positioning behaviours measures to support the coaches’ operating decisions.