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Gran parte de los juegos de pillar presentan comunicaciones motrices inestables entre los jugadores, es decir, la comunicación motriz (i.e. interacciones de cooperación, oposición o neutras) varía durante el juego debido al cambio de rol. El punto de vista holístico posibilita una valoración más completa de la experiencia de los jugadores durante el juego tradicional de pillar. Por lo tanto, los objetivos del estudio fueron presentar y emplear una propuesta para valorar las dimensiones relacional, emocional y física de jóvenes jugadores durante un juego motor. Veintidós jóvenes jugadores participaron en el estudio. Los jugadores jugaron a una modificación del juego de pillar durante 10 minutos. La dimensión relacional fue evaluada mediante la metodología observacional, analizando las contra-comunicaciones entre el que la lleva y el jugador contra-comunicado. La dimensión emocional fue evaluada mediante la escala BECS de disfrute y competencia percibida. La evaluación de la dimensión física fue realizada diferenciando los roles motrices mediante la medición de la Distancia Total recorrida por segundo. El análisis relacional aportó pistas sobre las relaciones sociales del grupo de participantes. Los altos niveles de disfrute (4.4 ± 0.6) y competencia percibida (4.0 ± 0.6) declarados por los jugadores sugieren el uso del juego tradicional de pillar durante las sesiones de Educación Física y de entrenamiento deportivo. El que la lleva recorrió una distancia significativamente mayor que el resto de los jugadores (p= .00; Tamaño del Efecto= 1.53 – 2.76), sugiriendo que la valoración de la dimensión física debería ser llevada a cabo diferenciando los roles motrices. La evaluación de la experiencia de los jóvenes jugadores durante los juegos motores desde un punto de vista holístico y diferenciando por roles podría ayudar a optimizar la intervención pedagógica. Many tag games present unstable motor communications between players, that is, the motor communication varies during the play due to role-changing. A holistic point of view provides a more complete assessment of the experience of the players during the traditional tag games. Thus, the aims of the study were to propose and use a specific guide to assess the relational, emotional, and physical dimensions during a traditional motor game in young players. Twenty-two young players took part in the study. The participants played a modification of the classic it motor game for ten minutes. The relational dimension was assessed by observational methodology analysing counter-communications between the tagger and the runner who experienced the counter-communication. The emotional dimension was assessed by the BECS scale of perceived enjoyment and competence. Physical dimension was assessed by differentiating the tagger, the runner, and the target-player measuring the Total Distance covered per second. The relational analysis provided clues about the social relationship of the group. The high values of enjoyment (4.4 ± 0.6) and perceived competence (4.0 ± 0.6) declared by players (suggested the use of the traditional tag game during Physical Education lessons and sport training. The tagger performed significantly greater total distance than the rest of the players (p=.00; Effect Size= 1.53 – 2.76), suggesting that the assessment of the physical dimension during motor games should be carried out differentiating the motor roles. The assessment of the experience of the players during the motor games differentiating by roles and from a holistic point of view could help to optimise the pedagogical plan. Grande parte dos jogos de pega-pega apresenta comunicações motoras instáveis ​​entre os jogadores, ou seja, a comunicação motora (i.e. interações cooperativas, opostas ou neutras) varia durante o jogo devido à câmbio de papel. O ponto de vista holístico permite uma avaliação mais completa da experiência dos jogadores durante o jogo tradicional de pega-pega. Portanto, os objetivos do estudo foram apresentar e utilizar uma proposta para avaliar as dimensões relacional, emocional e física de jovens jogadores durante um jogo motriz. Vinte e dois jovens jogadores participaram do estudo. Os jogadores jogaram um jogo de pega-pega modificado por 10 minutos. A dimensão relacional foi avaliada por meio da metodologia observacional, analisando as contracomunicações entre o apanhador e o jogador contracomunicado. A dimensão emocional foi avaliada por meio da escala BECS de prazer e competência percebida. A avaliação da dimensão física foi realizada diferenciando os papéis motrices através da medição da Distância Total percorrida por segundo. A análise relacional forneceu pistas sobre as relações sociais do grupo de participantes. Os altos níveis de prazer (4.4 ± 0.6) e competência percebida (4.0 ± 0.6) declarados pelos jogadores sugerem a utilização do tradicional jogo de pega-pega durante as sessões de Educação Física e treinamento esportivo. Aquele que o apanha percorreu uma distância significativamente maior (p= .00; Tamanho do Efeito= 1.53 – 2.76) do que o restante dos jogadores, sugerindo que a avaliação da dimensão física deve ser realizada diferenciando os papéis motrices. A avaliação da experiência de jovens jogadores durante os jogos motrices de um ponto de vista holístico e diferenciado por papéis pode ajudar a otimizar a intervenção pedagógica.

The aim of this study was to describe the team accumulated physical response per minute considering only the effective playing time (EPT) attending to different contextual and strategic variables in the Spanish Football First Division (

Rico-González, M, Pino-Ortega, J, Rojas-Valverde, D, and Arcos, AL. Comparing sampling frequencies to measure collective tactical variables during soccer training. J Strength Cond Res 36(10): 2862-2867, 2022-The sampling frequency of microsensors that measure the position of the players in team sports is a variable that could affect the accuracy of the measurement. The aim of this study was to assess the impact of the sampling frequency on the outcomes of tactical behavior variables during soccer training. Sixteen U16 male soccer players participated in the study. Three tactical variables (change in the geometrical center position [cGCp], mean distance between players [mean-DbP], and total area [TA]) were measured at 4 different sampling frequencies (i.e., 10, 4, 2, and 1 Hz) during a 7+goalkeeper-a-side soccer match by a time motion tracking system using inertial measurement units (IMU; WIMU PRO, RealTrack Systems, Almeria, Spain). Significant (p0.01) and substantial (ES = moderate-large) differences were found in the cGCp values across all sampling frequencies. Several significant (p0.05) and substantial (ES = small-moderate) differences were found in the mean-DbP values between 10 data per second and the rest of the sampling frequencies. There were no significant (p0.05) and substantial (ES = trivial) differences in the TA values across all sampling frequencies. The sampling frequency affects the outcomes of cGCp and mean-DbP but does not affect the values of TA. The outcomes of the studies that assess collective tactical behavior should be compared with caution if GC-related and distance variables were measured using different sampling frequencies. In addition, it seems that a smaller amount of data could be sufficient to measure area variables with greater magnitudes.

Background and purpose: Historically, sports training methodology, including soccer coaching, has been influenced by the pedagogic tend dominant in each epoch. Of late, the literature has espoused ...

The aim of the review was to identify the spatial tactical variables used to assess the use of space in team sports using positional data. In addition, we examined computational methods, performed a critical assessment and suggested future considerations. We considered four electronic databases. A total of 3973 documents were initially retrieved and only 15 articles suggested original spatial variables or different computation methods. Spatial team sport tactical variables can be classified into 3 principal types: occupied space, total field coverage by several players; exploration space, the mean location (±standard deviations in X- and Y-directions) of the player/team during the entire game; and dominant/influence space, the region the players can reach before any other players. Most of the studies, i.e., 55%, did not include goalkeepers (GKs) and total playing space to assess occupied space, however, several proposed new variables that considered that all playing space could be “played” (i.e. effective free-space, normalized surface area). Only a collective exploration space variable has been suggested: the major range of the geometrical centre (GC). This suggestion could be applied to assess collective exploration space variables at a sub-system level. The measurement of the dominant/influence space has been based on the Voronoi region (i.e. distance d criteria), but several studies also based their computation on the time (t). In addition, several weighted dominant areas have been suggested. In conclusion, the use of spatial collective tactical variables considering the principal structural traits of each team sport (e.g. players of both teams, the location of the space with respect to the goal, and the total playing space) is recommended.

The aim of this study was to look into the alleged impact of the physical fitness performance of elite junior soccer players on the professional career according to playing position. The physical tests (sprint test, countermovement jump [CMJ], and maximal aerobic speed [MAS]) performed by 165 players enrolled in the junior team of a Spanish 1st Division club (1998-2010) were evaluated. Players were classified as those who were promoted to the reserve team (Reserve Team) and those who were not (non-Reserve Team), and as those who were promoted to the Spanish 1st/2nd Divisions (PFL) and those who were not (NPFL) until the 2020-2021 season. Overall, no significant differences (p>.05) were found between the Reserve Team and non-Reserve Team or between the PFL and NPFL players in neuromuscular performance. Aerobic fitness was greater (pmoderate; mean difference = 3.0%) for the Reserve Team lateral midfielders in comparison to that for the non-Reserve Team. The results suggest that the impact of physical fitness on the promotion of elite junior soccer players is limited.

Principal Component Analysis (PCA) has not been used to assess the principal component (PC) of players´ external training loads (TL) in futsal. In addition, no previous study has analyzed the PC of players´ external TL depending on the half of the match in futsal. Thus, this study aimed to assess the PC of players´ external TL considering an entire official futsal match distinguishing by halves (1st and 2nd halves). Two teams of twelve amateur futsal players (Spanish 3rd division) participated in the final match of the futsal cup and external TL was quantified using eight antennas ultra-wideband technology. Through PCA statistical analysis, 10 variables formed the 10 PC. Specifically, three PC for the entire match, four for the 1st half, and three for the 2nd half were extracted. Considering the match as a whole, three PC explained the players´ external TL formed by eight variables: distance covered (m/min), distance covered at high speed running (m/min), distance covered at explosive speed (m/min), total accelerations (n/min), total decelerations between 2-1 m/s/s (n/min), distance covered at 24-50 km/h (m/min), total impacts between 8-100g (n/min) and Jumps performed (n/min). The PC variables differed between halves: a) in the 1st half 74.5% was explained by four PC composed of 8 variables in total, and b) in the 2nd half 67.6% was explained by three PC. The results suggest that the use of only one PC could potentially lead to an underestimation of the external TL demands in futsal matches. It seems that a combination of 3-4 PC from a total of 8 to 10 variables are required to explain senior amateur futsal official games. In addition, the match half should be considered to assess the external TL in team sports.

This study analyses the differential perceived match load accumulated by professional soccer players depending on their: (a) participation in several consecutive official matches within the same week (Pre_Cup, Cup, and Post_Cup), and (b) total match participation time (i.e. 90 min, 70-90 min and 0.05) in dRPE-ML among Pre_Cup, Cup and Post_Cup matches or in dRPE-ML between teams that took part in two or three official matches within the same week or three official matches in 2-4 consecutive weeks. The results suggest that participating in several matches in the same week does not increase accumulated perceived exertion for professional soccer players.

The aim of the study was to compare the agreement of the data on the kinematic demands and collective tactical variables during a professional soccer match between GPS and UWB sensors. The data wer...

The aim of the present study was to systematically review the origin and modifications of the geometrical centre (GC) in the assessment of team behaviour in team sports. Studies were identified following the PRISMA guidelines and PICO design for systematics reviews in four electronic databases (PubMed, SPORTDiscus, ProQuest Central, and Web of Sciences). A total of 3,973 documents were initially retrieved, of which 1,779 were duplicates. After checking 2,178, another 36 were added from the references of the studies. 72 articles met de inclusion criteria and 7 were included for the systematic review. Habitually, the GC is computed as the mean [X,Y] of several or all players in the sports team. Despite the relevance of the location of the players with respect to the goal, habitually, the goalkeeper/target has not been considered in the measurement of the GC. Two techniques (i.e. Hilbert transformation and cluster analyses) have been applied to analyse the synchronisation (i.e. relative phase) and the average mutual information (AMI) to assess the complexity and regularity or predictability of the GC in team sports. Since the GC does not consider the goalkeepers and team dispersion, this measure should be interpreted with caution, but together with other tactical variables can provide interesting information for team sports technical staff.

The main aim of this work was to review the use of technological tracking methods to assess collective spatial-positioning variables in team sports. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and PICO design for systematic reviews, study identification was performed in four databases (PubMed, SPORTDiscus, ProQuest Central, and Web of Science). Articles were selected if they focused on player position and technological tracking methods. After duplicate removal, 2194 articles were identified based on the established search criteria, of which 72 articles were selected and analysed. Semi-automatic optic-based systems, Global Positioning System/Global Navigation Satellite Systems, and local positioning systems were used in 60%, 33% and 7% of the studies, respectively. All studies that measured tactical variables by local positioning system technology in team sports used local position measurement technology. Optic-based systems were used more often in the early years to analyse collective tactical behaviour during competition. Later, Global Positioning System/Global Navigation Satellite Systems became more frequent to measure behaviour in team sports during the training process. The possibility of using the same system during competition and training will facilitate the assessment of collective tactical behaviour in team sports.

The aim of this study was to assess the changes in jump and sprint performances after the preseason period across 14 seasons depending on the initial performance level and the playing position in young professional soccer players. In total, 162 soccer players (age = 20.6 ± 1.8 years) belonging to the same reserve team of a Spanish La Liga club participated in this study. Countermovement jump (CMJ) and 5 and 15 m sprints were assessed in each season at the start of the preseason (July), Test 1 (T1), and the start of the competitive period (September), Test 2 (T2), from the 1998 to 2013 seasons. Considering all seasons, a trivial change was found in the sprint (5 m, Effect Size [ES] = −0.01; ±0.11, most-likely; and 15 m, ES = 0.05; ±0.09, most-likely) and countermovement jump (CMJ) performances (ES = −0.03; ±0.07; most-likely) after the preseason, but this varied across the seasons. While the fastest players in 5 m and 15 m tests and the most powerful worsened their performances in sprinting capacity (ES = 0.53–0.65, small very-likely) and in jump ability (ES = −0.54; ±0.25, small very-likely), respectively, the slowest players and the less powerful improved their performance likely/most-likely (ES = −0.33 and −0.68, small and moderate) and very-likely (ES = 0.40; ±0.20, small) after the precompetitive period. The changes in CMJ and sprinting were trivial and trivial/small for all tactical positions. The changes in neuromuscular performance after the preseason were not stable across the seasons and varied depending on the initial performance level. Individualization strategies should be considered in the design of strength and conditioning programs in order to optimize the training process.

The aim of this study was threefold: 1) to assess the configuration of an elite reserve soccer team, 2) to compare physical fitness performance of promoted and new players according to the playing position, and 3) to analyze the level of competitive participation attained by these players. We considered physical fitness tests (5 m and 15 m sprint, countermovement jump [CMJ] and aerobic endurance) performed by 192 players (age = 20.2 ± 2.3 years) enrolled in the reserve team of a Spanish La Liga club from 1994 to 2013. The players were classified according to the previous club criterion (promoted from the soccer academy and new players signed from other clubs), b) their playing position, and c) the competitive level attained until the 2016/2017 season (Spanish 1st and 2nd Divisions and the remaining competition levels). The proportion of promoted and new players was similar (p = 0.47). Overall, no substantial differences (unclear-small) were found in physical fitness performance between promoted and new players. Considering the playing position, promoted lateral defenders (LDs) showed better sprinting (ES = moderate) and CMJ (ES = moderate) performance than new LDs. In addition, promoted central midfielders (CMs) demonstrated better performance in the 5 m sprint and the CMJ (ES = moderate) than new CMs. The percentage of players who later competed in the Spanish 1st and 2nd Divisions was greater in promoted players compared to new players (p = 0.006). Physical fitness performance did not determine the selection of new players in a soccer elite reserve team. We may conclude that soccer academies should prioritize the selection and the training process of youth soccer players.

Due to technological developments and permission from federations such as FIFA, radio-frequency based technology (i.e. Global Positioning Systems (GPS) or Global Navigation Satellite Systems (GNSS) and Local Positioning Systems (LPS)) has become popular in team sports. Today, real-time feedback is available due to the development of WBAN (Wireless Body Area Networks) in data transmission possibilities from devices to the PC, tablet or mobile, where the data are shown, offering a competitive advantage for team sports. However, there is debate about the accuracy of real-time data versus data downloaded after a session. It has been found that whilst the signal exceeded the noise for real time collection for total distance, this was considerably reduced during lower intensity efforts (smaller meaningful distance [SMD]) for jogging (4.2 to 5.0 m∙s−1) = 33.5 m; running (5.0 to 6.9 m∙s−1) = 31.9 m; sprinting = 17.3 m). Similarly, post-session PlayerLoad™ data have been found to be both reliable and valid in real-time using microelectromechanical systems (MEMS), while moderate errors were found when compared to the data downloaded directly from the device. Therefore, it seems that real-time feedback will be a valuable tool for sports technicians. However, although there has been great development in real-time feedback, manufacturers should further develop their systems to guarantee high quality measures.

This study aims at assessing physical fitness performance and its relationship with the differential ratings of perceived exertion of training load (dRPE TL) and match load (dRPE ML) in a Spanish p...

Team-lines structures are particular subsystems determined strategically by the formation chosen by the team coach, and despite its relevance, no study has analyzed training effects on tactical behavior based on team lines. This study aimed to assess the effects of modified games playing freely and introducing artificial rules on tactical behavior based on team lines during the team-possession game phase in two youth-soccer categories. Two Spanish under-14s (U-14s: n = 16) and under-16s (U-16s: n = 16) teams took part in the study. Each team was divided into two groups, free-play and conditioned, that faced each other during three 7-min eight-on-eight games in four training sessions. The free-play group played freely without restrictions, while the conditioned group played constrained by artificial rules (i.e. a minimum number of touches, no return pass allowed, forward pass after a back pass) that modified the cooperative motor interactions between teammates. Tactical behavior was assessed by the three geometrical primitives’ representations (i.e. node: change in the centroid position (CCP), line: interpersonal distance between teammates (dyads), and area: surface area (SA)) and their time series approximate entropy (ApEn) normalized measures in subgroups based on team lines (goalkeeper – defenders, defenders – midfielders, and midfielders – forward) before and after the training intervention in an eight-on-eight game using a local positioning system (LPS). The results suggest that the short-term training intervention affected considerably (i.e. Cohen’s d≥ moderate) U-14s team lines’ behavior, especially those who played freely. On the other hand, U-16s’ tactical behavior based on team lines barely changed (i.e. Cohen’s d≤ small). It seems that playing freely for several training sessions could strengthen the tactical behavior of each line, enhancing team lines’ regularity in youth-soccer categories.

Most of the reviews carried out in sports science have used the general items suggested by Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). Due to the specific requirements of each knowledge area, several modifications of the PRISMA are necessary to optimize the process of the systematic reviews and, in consequence, the quality of the conclusions provided in this type of study. Therefore, this work aimed to adapt PRISMA to provide specific guidelines to carry out systematic reviews in sports science. The methodology criteria (search strategy, databases, and eligibility) and the results section (flow diagrams and study contents) were adapted based on previous studies, and several new considerations were added to design the new guidelines. We compiled 28 items suggested by sports science researchers and included two new items: (i) population/problem (i.e., age, level, and country) and (ii) the entire training process, which is monitored and compared between groups (e.g., total training load). To maximize the benefit of this document, we encourage people to read it in conjunction with the PRISMA statement. The main differences between PRISMA and the PRISMA adapted to sports science were related to registration, search strategy, flow diagrams, and results. Application of the new guidelines could improve the information provided to readers and make it easier to generalize and compare the results in sports science.

Background: Local positioning systems have shown high accuracy for measuring the distance covered and the mean velocities and also for time-motion analysis. However, no study has assessed the accuracy and inter-unit agreement of local positioning system [LPS] technology to compute any collective tactical behavior variable. Objective: The main aim of the study was to analyze the accuracy of ultra-wideband and calculate inter-device agreement to compute the geometrical center coordinates (i.e., the relative positioning of each team represented in a single point computed considering x and y coordinates of the players). Methods: The inter-device geometrical center agreement of the devices when placed in the corners [static] of a basketball court was also assessed. The geometrical center (x, y coordinates) computed by a local positioning system tool, called an inertial measurement unit, was compared to the known geometrical center position in four different court areas: [1] 15x7 m, [2] 15x14 m [3] 15x21 m [4] 15x28 m. In each of the court areas, two different devices were placed on three tripods [60 cm from the floor] in three corners of the perimeter described. The distance of the device to the reference element was calculated every 0.5 s, providing a total of 600 samples. The absolute difference between the geometrical center measured on the ultra-wideband devices and the real geometrical center was less than 0-1.1%, with an absolute difference of 0 to 0.09 m in all the court areas. Results: The difference between the devices when the geometrical center was computed was from 0.14 to 1.36%, with an absolute difference of 0.02 to 0.09 m. The accuracy of the ultra-wide band and inter-device agreement for computing the geometrical center was high (absolute error < 10 cm). Conclusion: These findings may suggest future validation protocols of the ultra-wide band for the assessment of collective tactical variables in team sports under a real match or training conditions.

The main objective of this study was to evaluate the concordance between the coaches and the players of a Spanish highlevel female basketball team when evaluating the hardness of practice sessions looking into the factors that could modulate the alleged biases of the coaches. The three staff members severely underestimated the players' session perceived exertion, which meant that, as a group, they were not capable of planning the desired intensity along the registered period. Furthermore, this study allowed us to detect what aspects of coaching knowledge should deserve more attention with each staff members if we desired less biased judgments about the players' perceptions, who were the most relevant and common source of bias. El principal objetivo de este estudio fue evaluar la concordancia entre los entrenadores y los jugadores de un equipo femenino español al valorar la dureza de las sesiones de entrenamiento, prestando especial atención a los factores moduladores de los posibles sesgos en el cuerpo técnico. Los tres entrenadores infravaloraban notablemente los valores de fatiga declarados por los jugadores tras las sesiones, lo que implicaba que, en conjunto, no eran capaces de planificar correctamente la intensidad del ejercicio propuesto en cada periodo. En este sentido, esta investigación nos permitió detectar en qué aspectos del pensamiento de cada entrenador se debía incidir para reducir sus sesgos particulares y el más común entre los tres: los jugadores mismos.

Ultra-wide band (UWB) based local positioning systems (LPS) are based on devices and a portable antenna set. The optimal installation height of the antennae is crucial to ensure data accuracy. Collective variables are metrics that consider at least two pairs of coordinates, which may lead to lower precision than an individual one. Therefore, the aim of this study was to compare the influence of antenna height with collective metrics using a UWB (i.e., IMU, WIMU PRO™, RealTrack Systems, Almeria, Spain) based LPS. Data acquisition was carried out in a basketball court measuring 28 × 15 m. Five devices were used, one of which was carried by a healthy and well-trained athlete (age: 38 years, mass: 76.34 kg, height 1.70 m), while each of the remaining four was positioned on a tripod in one of the four corners of the court. Four kinds of variables were extracted: (1) static distances, (2) dynamic distances, (3) static areas and (4) dynamic areas in all antenna installation modes of 0.15, 1.30 and 2.00 m. The results showed that the antenna of 1.30 m provided better accuracy for all measures (% difference range from −0.94 to 1.17%) followed by the antenna of 2.00 m (% difference range from −2.50 to 2.15%), with the antenna of 0.15 m providing the worst accuracy level (% difference range from −1.05 to 3.28%). Overall, the measurements of distance metrics showed greater accuracy than area metrics (distance % difference range from −0.85 to 2.81% and area % difference range from −2.50 to 3.28). In conclusion, the height of the antennae in basketball courts should be similar to the height at which the devices are attached to a player’s upper back. However, as the precision is sensitive to the magnitude of the measure, further studies should assess the effects of the relative height of antennae in team sports with greater playing spaces.

Motor behavior assessment during games could help physical education teachers and team coaches to design effective and efficient motor interventions. This study aimed to assess the variability of the physical and behavioral responses during continued practice of the game tail tag with a ball. Sixteen Spanish youth soccer players from an under-14 team played tail tag, with a ball, during four sessions (5 repetitions of 1 min per session). Physical (i.e., Total Distance (TD) and PlayerLoad (PL)) and behavioral (i.e., Surface Area (SA) and change in the Geometrical Centre position (cGCp)) dimensions were assessed with a local positioning system. The mean of the five series of each session was considered for further statistical analysis. The main finding was that the external load decreased (d = small &minus, large) and the use of space varied during the continued practice of tail tag. Initially, SA increased substantially (d = large) and cGCp decreased slightly (d = small), and then both variables tended to stabilize. This suggests that after several repetitions of the same motor game, physical education teachers and team sports coaches should use this again later, modifying this or proposing new motor games where players respond to these activities that consist in greater uncertainty than to well-known motor games.

Although many studies on collective tactical behaviour have been published in the last decade, no study has revised and summarized the findings provided for futsal. The main aim of this systematic review was to identify and discuss the geometrical centre (GC), distance and area tactical variables used to assess team behaviour in futsal. In addition, it summarizes the findings on the tactical response during futsal competition and training. A systematic review of the relevant articles provided on futsal was carried out using seven electronic databases (SPORTDiscus, ProQuest, Cochrane Plus, Scopus, Google Scholar, PubMed and Web of Science) until September 25, 2019. From a total of 1,209 studies initially found, 12 were included in the qualitative synthesis. There were some trends in the analysis of positional data in futsal with the most relevant situations analysed being 1 vs 1 and 5 vs 4+Goalkeeper. The distances and angles between two points were the most assessed tactical variables. Five types of distance variables were used to assess collective tactical behaviour in futsal: GC-GC, GC-player, player-player, player-ball and player-space. Pressure (GC-GC) was greater in shots on goal than in tackles during professional futsal matches. Area variables were reduced to occupied space, exploration space and dominant area. Occupied space was measured only during competition while the dominant area was measured only during training sessions. The surface area and dominant regions were greater when players were attacking in comparison to when they were defending. In addition, two non-linear techniques (i.e. relative phase and entropy) were applied to analyse synchronisation and complexity and regularity or predictability. Defenders were highly synchronous, while attackers tried to break this coordination to achieve possibilities for action. Task constraints are suitable to induce different regularity patterns. This review is an opportunity to develop studies aimed at bridging the gap in collective tactical behaviour in futsal. The authors gratefully acknowledge the support of a Spanish government subproject Integration ways between qualitative and quantitative data, multiple case development, and synthesis review as main axis for an innovative future in physical activity and sports research [PGC2018-098742-B-C31] (Ministerio de Ciencia, Innovacion y Universidades, Programa Estatal de Generacion de Conocimiento y Fortalecimiento Cientifico y Tecnologico del Sistema I+D+i), that is part of the coordinated project New approach of research in physical activity and sport from mixed methods perspective (NARPAS_MM) [SPGC201800X098742CV0

Match collective tactical behaviours can be used as a reference to design and select training strategies to improve individual and team performance in professional football. The aim of the systematic review was to cluster the collective tactical variables used to highlight and compare male soccer teams' collective behaviour during professional official matches, providing reference values for each of them. A systematic review of relevant articles was carried out using three electronic databases (PubMed, SPORTdiscus and Web of Science). From a total of 1,187 studies initially found, 13 original articles were included in the qualitative synthesis. The articles found concerned studies carried out on the Spanish, Portuguese, English and Brazilian 1

The aims of this study were to describe the evolution of the anthropometric profile of soccer players over a decade and to compare the anthropometric profiles of players promoted from an elite reserve team to high-level soccer with those players who were not promoted. We examined the body mass, height, body-mass index, and body fat of 98 players enrolled in the reserve team from 2008 to 2018. The players were classified in terms of (a) the highest competitive level they achieved up to the 2019/2020 season (i.e., Spanish 1st&ndash, 2nd divisions or semi-professional), (b) the period in which they played their last season on the team, and (c) their playing position. Over time, the height of goalkeepers, lateral midfielders, and attackers has increased (effect size = 0.66 &plusmn, 1.13) but has decreased in central midfielders (effect size = 0.83). The body fat of defenders has also fallen (effect size = 0.55 &plusmn, 0.95). Spanish high-level goalkeepers, lateral midfielders, and attackers were taller than their semi-professional player counterparts (effect size = 1.20 &plusmn, 1.98). Body fat did not determine promotion from a reserve team to high-level soccer, but height may be an advantage for several playing positions. The assessment of the anthropometric profile and the application of interventions should be designed according to the playing position.

The aims of the study were: a) to analyze the reproducibility of the Modified Agility Test (MAT) according to two types of displacement (i.e. constrained [MATtop] vs. free [MATfree]), b) to examine the explanatory capacity of anthropometric characteristics and neuromuscular performance on the ability to change the direction (CODA), c) to look into the practical consequences of the types of displacement from the perspective of an elite soccer academy. 118 male soccer players (age: 16 (13-25) years old) from the same elite Spanish soccer academy (U13 to senior) were tested twice on two versions of the MAT (MATtop and MATfree), with 48 hours between testing sessions. Moreover, they were tested on linear-sprint performance, over 5 m (S5m) and 15 m (S15m), and the vertical jump (VJ) (countermovement jump with [ACMJ] and without an arm swing [CMJ]). The main findings were: a) the type of displacement did not affect the reliability of the CODA test; b) weight, S15m, ACMJ and CMJ variables explained close to 60% of CODA performance; c) MATtop (i.e. constrained displacement) and MATfree (i.e. free-displacement) CODA tests could show different profiles of development along the age groups; and d) the impact of the task’s constraints was relatively higher in U16 and U17 groups. CODA seems to have a variable meaning depending on the characteristics of the test and the age of the participants.

This study aimed to compare the collective dynamics of three different age-level groups (i.e., U13, U15 and U18) during a 4 vs. 4 plus goalkeepers small-sided game (SSG). Fifty-four male outfield soccer players aged between 13 and 18 years took part in the study. Team tactical behaviors were assessed by measuring (a) the area occupied by players of each team, (b) the distance between both teams&rsquo, centroids, (c) the players&rsquo, distance to their own team and d) the stretch index during a 4 vs. 4 plus goalkeepers SSG format. The main results revealed that larger areas were occupied by the older players (P &lt, 0.001, Effect size (ES) = 0.44&ndash, 0.25, small). Additionally, the mean distance between teams&rsquo, centroids was greater in older groups (P &lt, ES = 0.44&ndash, 0.81, large&ndash, small). Finally, the distance between players (P &lt, ES = 0.75&ndash, 0.81, moderate&ndash, large) and the stretch index (P &lt, 0.47, small) were also greater in older age categories. The evidence provided in the present study might help coaches identify the influence of age on collective dynamics during SSGs and help them find task conditions that could help to improve the behaviors and positioning of younger players.

The aims were to assess differentiated perceived match exertion and its variability according to playing position for professional soccer players. Nineteen Spanish players declared their respiratory and muscular perceived exertions (PEs) after official matches during an entire season. Players were classified according to their playing position. In order to assess differentiated perceived match exertion, soccer players were asked to assess their perceived level of exertion following each official match. Considerable differences (p

This study aimed to assess the match perceived exertion (PE) declared by starter and non-starter junior elite soccer players, according to the level of the opponents, and by playing at home or away. Nineteen young soccer players who competed in the Spanish U19 League participated in this study. PE was registered during the entire regular season (30 official matches). Players were grouped by match playing time: starters (players who started the game and played at least 45 min) and non-starters (substitute players who participated for less than 45 min). Moreover, the matches were classified according to the opponent level (i.e., high, medium, or low) and the match location (i.e., home or away). Starters who competed against high-level opponents (8.7 &plusmn, 0.6) declared higher PE ratings than against medium (8.1 &plusmn, 0.7, p &lt, 0.01) and low (8.4 &plusmn, 0.01) level opponents. In addition, starters competing at home declared lower PE ratings than when playing away (8.2 &plusmn, 0.8 vs. 8.5 &plusmn, 0.6, p &lt, 0.01). However, no significant differences (p &gt, 0.05) were observed for non-starters. Coaches should consider not only tactical&ndash, strategic needs, but also these contextual factors when managing the match playing time of the starter players.

The use of valid, accurate and reliable systems is decisive for ensuring the data collection and correct interpretation of the values. Several studies have reviewed these aspects on the measurement of movement patterns by high-definition cameras (VID) and Global Positioning Systems (GPS) but not by Local Positioning Systems (LPS). Thus, the aim of the review was to summarize the evidence about the validity and reliability of LPS technology to measure movement patterns at human level in outdoor and indoor stadium-scale. The authors systematically searched three electronic databases (PubMed, Web of Science and SPORTDiscus) to extract studies published before 21 October 2019. A Boolean search phrase was created to include sport (population; 8 keywords), search terms relevant to intervention technology (intervention technology; 6 keywords) and measure outcomes of the technology (outcomes; 7 keywords). From the 62 articles found, 16 were included in the qualitative synthesis. This systematic review revealed that the tested LPS systems proved to be valid and accurate in determining the position and estimating distances and speeds, although they were not valid or their accuracy decreased when measuring instantaneous speed, peak accelerations or decelerations or monitoring particular conditions (e.g., changes of direction, turns). Considering the variability levels, the included studies showed that LPS provide a reliable way to measure distance variables and athletes’ average speed. For the case of the F.M.C., this work is funded by FCT/MCTES through national funds and when applicable co-funded EU funds under the project UIDB/ EEA/50008/2020.