Search Results (148)

The development of Global Positioning System (GPS) technology has contributed in various ways to improving the physical condition of modern football players by enabling the quantification of physical load. Previous studies have reported that the running demands of matches vary depending on playing position and formation. Over the past decade, despite the widespread use of GPS technology, studies that have investigated the running performance of young football players within the 1-4-3-3 formation are particularly limited. Therefore, the aim of the present study was to create the match running profile of playing positions in the 1-4-3-3 formation among high-level youth football players. An additional objective of the study was to compare the running performance of players between the two halves of a match. This study involved 25 football players (Under-19, U19) from the academy of a professional football club. Data were collected from 18 league matches in which the team used the 1-4-3-3 formation. Positions were categorized as Central Defenders (CDs), Side Defenders (SDs), Central Midfielders (CMs), Side Midfielders (SMs), and Forwards (Fs). The players’ movement patterns were monitored using GPS devices and categorized into six speed zones: Zone 1 (0.1–6 km/h), Zone 2 (6.1–12 km/h), Zone 3 (12.1–18 km/h), Zone 4 (18.1–21 km/h), Zone 5 (21.1–24 km/h), and Zone 6 (above 24.1 km/h). The results showed that midfielders covered the greatest total distance (p = 0.001), while SDs covered the most meters at high and maximal speeds (Zones 5 and 6) (p = 0.001). In contrast, CDs covered the least distance at high speeds (p = 0.001), which is attributed to the specific tactical role of their position. A comparison of the two halves revealed a progressive decrease in the distance covered by the players at high speed: distance in Zone 3 decreased from 1139 m to 944 m (p = 0.001), Zone 4 from 251 m to 193 m (p = 0.001), Zone 5 from 144 m to 110 m (p = 0.001), and maximal sprinting (Zone 6) dropped from 104 m to 78 m (p = 0.01). Despite this reduction, the total distance remained relatively stable (first half: 5237 m; second half: 5046 m, p = 0.16), indicating a consistent overall workload but a reduced number of high-speed efforts in the latter stages. The results clearly show that the tactical role of each playing position in the 1-4-3-3 formation, as well as the area of the pitch in which each position operates, significantly affects the running performance profile. This information should be utilized by fitness coaches to tailor physical loads based on playing position. More specifically, players who cover greater distances at high speeds during matches should be prepared for this scenario within the microcycle by performing similar distances during training. It can also be used for better preparing younger players (U17) before transitioning to the U19 level. Knowing the running profile of the next age category, the fitness coach can prepare the players so that by the end of the season, they are approaching the running performance levels of the next group, with the goal of ensuring a smoother transition. Finally, regarding the two halves of the game, it is evident that fitness coaches should train players during the microcycle to maintain high movement intensities even under fatigue. Full article

Background: Pre-season training is critical for developing tolerance to high physical demands in professional soccer, and nitric oxide (NO) precursors such as dietary nitrate (NO₃⁻) and citrulline malate (CM) can support performance and recovery during this demanding phase. This study aimed to examine the effects of a four-week supplementation protocol combining 500 mg of NO₃⁻ from amaranth extract and 8 g of CM (NIT + CM) on external training load and post-match recovery in professional female soccer players during pre-season. Methods: A randomized, double-blind, placebo-controlled trial was conducted with 34 female soccer players who received either the NIT + CM product or a placebo for four weeks during pre-season. Global positioning system (GPS)-derived external load was recorded throughout the intervention. Performance tests—a countermovement jump (CMJ) test and the Wingate anaerobic test (WAnT)—and blood sampling for plasma NO₃⁻ and nitrite (NO₂⁻) concentrations were conducted at baseline and the day after a competitive match. Results: The supplementation with NIT + CM increased maximal speed (Vmax) throughout training and match play. During post-match testing, the NIT + CM group exhibited a significantly smaller decline in mean (P_mean) and minimum (P_min) power during the WAnT, along with reduced power loss in both the first (0–15 s) and second (15–30 s) intervals. Plasma NO₃⁻ concentrations significantly increased from baseline in the NIT + CM group and remained elevated 24 h after the final dose, confirming sustained systemic exposure. Conclusions: Chronic NIT + CM supplementation may enhance Vmax and help preserve anaerobic performance the day after a match. These effects could reflect improved tolerance to high training loads and sustained NO₃⁻ availability during recovery. Full article

Background/Objectives: The role of body composition in sports performance has been widely studied, particularly in soccer. Understanding how anthropometric characteristics impact movement efficiency and neuromuscular performance is crucial for optimizing player performance. This study examined the relationship between body composition and locomotor performance in elite soccer players. Methods: Thirty-six male soccer players from the Mexican National Team participated in the study, where body composition was assessed using surface anthropometry. Players underwent tests to measure countermovement jump (CMJ) performance, sprinting speed, maximum acceleration, and distance covered during two games of the CONCACAF Nations League quarterfinals. Correlation matrices were created to identify the most significant associations, followed by generalized linear models (GLMs) to associate body composition variables with performance metrics. Results: Anthropometric profile tables were created by playing position. Higher body fat percentage (%BF) was associated with lower performance. Specifically, higher %BF was associated with slower sprint speed (B = −0.74 m/s, p < 0.001) and shorter distance covered (B = −4.86 m/min, p < 0.001). Conversely, greater muscularity, reflected by corrected girth values for the thigh and calf, was associated with improved CMJ performance. Thigh corrected girth was positively associated with concentric mean force (B = 48.85 N, p < 0.001), and calf corrected girth was positively associated with peak power (B = 240.50 W, p < 0.001). These findings underscore the importance of low body fat and high lean mass for efficient movement. Conclusions: The results highlight the critical role of body composition in enhancing soccer performance, particularly for explosive movements like jumps, sprints, and accelerations. This study suggests that monitoring and optimizing body composition should be a central focus of nutrition, training, and conditioning strategies, adapted to the specific positional demands of professional soccer. Full article

Background: The motor response to human visual stimuli is unique and differs from the reaction to light-based visual stimuli. While laboratory-based tests offer valuable insights into athletes’ basic perceptual–motor abilities, their translation to actual sports-specific tests is limited. Methods: Following a thorough warm-up, 44 collegiate-level male soccer players (age: 24.4 ± 2.5 y, mass: 63.01 ± 7.3 kg, stature: 167.62 ± 6.3 cm) from a tertiary institution completed the following tests: Sports Vision Test (20-light proactive speed test), 40 m sprint test (split times over 5, 10, 20 and 40 m), and a live Reactive Agility Test (RAT) entailing them to sprint, change direction either towards their dominant limb or non-dominant limb in response to a live tester, and sprint again. Results: Numerous moderate correlations were seen between the RAT and various sprint distances (r > 0.3, ES > 0.3, p < 0.05). The reaction speed relationship between the light-based (SVT) and live stimuli (RAT) test yielded a weak relationship (r > 0.4, ES > 0.5, p < 0.05). Furthermore, the light-based hand–eye coordination speed did not predict acceleration or top speed, while the total RAT time did explain 10.5% of top speed (40 m). No significant differences in the SVT average and total time were found among playing positions. Conclusions: The limited correlations observed indicate that light-based reaction training alone may not be sufficient to translate to field-based reactive agility; therefore, training should integrate perceptual–cognitive and motor demands. Future research should refine laboratory-based tests by incorporating contextual elements to enhance ecological validity and further investigate the transferability of these skills from controlled settings to real-world game scenarios. Full article

Background: Blind 5-a-side soccer is an intermittent sport that requires the integration of physiological and physical processes, where body composition (BC) is an influential and differentiating factor of the sporting level, according to the conclusions of some studies. However, to date, no systematic review has been reported comparing BC in players with visual impairment. Objectives: The aims of this study were to systematically synthesize the existing evidence on differences in anthropometric characteristics and body composition among blind 5-a-side football players according to playing position and to derive practical recommendations for researchers and coaches. Methods: The following databases were consulted: PubMed (Medline), Scopus, Web of Science, and Science. This systematic review uses the guidelines of the PRISMA declaration and the guidelines for conducting systematic reviews in sports science. PICO strategy was used for the selection and inclusion of studies in the present work, with a series of inclusion and exclusion criteria. The quality was methodologically assessed using the PEDro scale. Results: The 10 studies comprising this systematic review had a total sample size of 168 athletes. The main findings of this research were (1) the somatotype of blind 5-a-side soccer players tends toward meso-endomorphic; (2) there are differences in the variables of muscle mass, fat mass, and body weight in response to playing position and sporting level; (3) the players present a somatotypical profile with a predominance of the mesomorph component. Conclusions: The results of this review reveal a tendency to define BW as influencing the athletic performance of blind 5-a-side soccer players. However, it is not conclusive whether these improvements occur in response to each playing position. More studies are needed to analyze the effect of BW on athletic performance, especially when correlating BW with other physical, nutritional, technical, and tactical variables in training and competition. Full article

Physiological characteristics such as VO_2max, running economy (RE), maximal aerobic speed (MAS), maximal sprinting speed (MSS), anaerobic speed reserve (ASR), and player profiling (based on MSS and MAS) have been proven to be important for training prescriptions in football. However, previous studies on player profiling have neglected the absolute values of MSS and MAS. The objectives of this study were to compare the aforementioned physiological variables among player roles, create benchmarks, and provide normative data to help coaches categorize players, ultimately proposing a new player profiling method. We analyzed 195 male professional football players (50 forwards, 59 midfielders, 44 full-backs, and 42 center-backs). Multivariate analysis of variance with Tukey’s post hoc tests revealed positional differences. Center-backs exhibited lower VO_2max than midfielders and full-backs. Both center-backs and forwards showed poorer RE and MAS compared to midfielders and full-backs. Full-backs achieved higher MSS than midfielders and center-backs, and forwards outperformed center-backs. Finally, midfielders demonstrated lower ASR than all other positions. Benchmarks based on T-scores for all variables were provided. Finally, in the new profiling method proposed—also based on T-scores—players were classified as “speed”, “endurance”, or “hybrid” if their MAS and/or MSS T-score exceeded 60, “in development” if both were below 45, and “average” if both scores were between 45 and 60 without any value above 60. The normative data provided can assist coaches in identifying specific areas for improvement in players’ physical conditioning—particularly valuable for youth athletes or those returning from injury. Additionally, the new profiling method offers insights into individual player characteristics, enabling more tailored and effective training interventions. Full article

Objectives: This study aimed to compare the worst-case scenario (WCS; i.e., 1-min) demands, in terms of distance covered and the number of times exceeding 85% of WCS demands, across soccer playing positions and match periods. Methods: A total of 67,518 records from 380 soccer matches during the 2023/24 season of the First Spanish Division were collected. Match events were tracked using the optical tracking system ChyronHego^® (TRACAB Gen5, NY, USA) and synchronized with Mediacoach software (LaLiga, Madrid, Spain). Total distance (TD), very high-speed running (VHSR), and sprint distance were considered, and all analyses were performed using linear mixed models (LMM). Results: Center-backs (CBs) exhibited significant differences (p < 0.001) in TD compared to all other positions. Regarding actions exceeding 85% of the 1-min WCS for TD, full-backs (FBs) showed significant differences compared to CBs (p < 0.001), midfielders (MDs; p < 0.001), and attacking midfielders (AMs; p < 0.001). In terms of VHSR, significant differences were observed between MDs and wingers (Ws; p < 0.05). In relation to match periods, during 15–30, CBs demonstrated significant differences compared to all other positions for actions exceeding 85% of the 1-min WCS in TD. Conclusions: These findings suggest that training protocols could be adjusted to account for specific positional demands, particularly focusing on high-speed running and sprint actions. Full article

Background: A comprehensive understanding of variations in physical attributes both between and within young players is crucial for accurately identifying talent based on physical performance. This study aimed to compare maximum strength, jump, and sprint test results among young soccer players from different age categories and playing positions. Secondarily, this study aimed to analyze the association between maximum strength, jump, and sprint performances. Methods: A total of 103 players were categorized as U23, U19, U17, and U16. The players were placed into these age categories based on their football abilities. All participants completed standardized warm-ups, and testing procedures followed protocols established in previous studies. Results: Significant differences were found between age categories regarding the Isometric Mid-Thigh Pull (p < 0.001; η²_p = 0.33), Countermovement Jump (CMJ) (p < 0.001; η²_p = 0.50), Squat Jump (SJ) (p < 0.001; η²_p = 0.29), and sprint (p < 0.001; η²_p = 0.30) tests. No significant differences were detected in Broad Jump results between age categories. Moreover, no significant differences were observed in any physical capacities between playing positions. Furthermore, significant moderate-to-strong correlations (r = 0.30–0.86) were observed between all physical tests. Conclusions: Age categories can distinguish soccer players’ performance in different physical tests while no differences were observed between playing positions. Similar magnitude correlations were observed across all tests with only the CMJ and SJ being strongly correlated. Coaches and strength and conditioning professionals should apply a variety of tests to assess different physical qualities since they have different patterns between age categories. Full article

As robots become increasingly integrated into society, a future in which humans and robots collaborate is expected. In such a cooperative society, robots must possess the ability to predict human behavior. This study investigates a human–robot cooperation system using RoboCup soccer as a testbed, where a robot observes human actions, infers their intentions, and determines its own actions accordingly. Such problems have typically been addressed within the framework of multi-agent systems, where the entity performing an action is referred to as an ‘agent’, and multiple agents cooperate to complete a task. However, a system capable of performing cooperative actions in an environment where both humans and robots coexist has yet to be fully developed. This study proposes an action decision system based on self-organizing maps (SOM), a widely used unsupervised learning model, and evaluates its effectiveness in promoting cooperative play within human teams. Specifically, we analyze futsal game data, where the agents are professional futsal players, as a test case for the multi-agent system. To this end, we employ Tensor-SOM, an extension of SOM that can handle multi-relational datasets. The system learns from this data to determine the optimal movement speeds in x and y directions for each agent’s position. The results demonstrate that the proposed system successfully determines optimal movement speeds, suggesting its potential for integrating robots into human team coordination. Full article

Youth soccer academies are dominated by the older players in each annual age cohort because they are judged to be better at the time of selection. Failing to identify talented players because they are simply younger in their cohort is a problem of both discrimination and poor practice. One potential method for addressing such biases is to develop and use age- and size-corrected assessments of individual players using traits closely associated with match success. In this study, we quantified the relationship between age and size with individual passing and control performance in six different tests for 170 players between 10 and 20 years old from a Tier 1 academy in Brazil. Passing tests were significantly repeatable and performance varied among tests (df = 5; F = 432.2; p < 0.001). Overall passing performance (PC_P1)—based on all tests—was significantly positively associated with age (R² = 0.42, t = 10.67; p < 0.001), height (R² = 0.19, t = 6.13; p < 0.001) and mass (R² = 0.23, t = 6.90, p < 0.001). In addition, tests of passing and control could discriminate among groups of differing playing levels (test 1: F_(2,116) = 55.2, p < 0.001; test 3: F_(2,116) = 12.0, p < 0.001). Normative algorithms from this study can be used to compare athletes during selection trials and against an elite group, after taking age and size into account, and using such algorithms could vastly reduce the insipid age-biases that plague youth football. Full article

Acceleration and Acceleration-Initial Speed Running are important factors in soccer performance. The aims of the study were (a) analyze by playing position the acceleration-initial speed (AS₀) profile and (b) analyze the relevance of the number of accelerations > 3 m·s⁻² according to final league position. The subjects (n = 309) from the Spanish First Division during the 2021–2022 and 2022–2023 seasons were classified in six positions: Central Defenders (CD), Full Backs (FB), Central Midfielders (CM), Offensive Midfielders (OF), Wingers (W), and Forwards (F). A total of 6180 match observations were recorded using the Mediacoach System. The parameters analyzed were accelerations > 3 m·s⁻² and AS₀ profile variables, maximal theoretical acceleration (A_0Int), and maximal theoretical initial running speed (S_0Int). The AS₀ profile was calculated using a linear regression model. Welch’s analysis of variance (ANOVA) revealed a consistent relationship between the A_0Int variable of the AS₀ profile and team success in CM, FB, and W positions. Moreover, the successful teams for CD, CM, FB, OM, and W positions showed a statistically higher number of accelerations > 3 m·s⁻² than unsuccessful teams. In conclusion, these findings suggest the importance of enhancing acceleration abilities, particularly for lower-performing teams, to achieve the physical standards of successful teams. Full article

Environmental temperature (T_e) is a main atmospheric parameter that may affect the physical and physiological demands of outdoor sports. Thus, this study aimed to examine the relationship of T_e with the physical and physiological demands of beach soccer match-play. Physical and physiological demands were collected from 60 male players during Portuguese elite beach soccer championship matches using a 10 Hz wearable global positioning system, heart rate, and the rate of perceived exertion (RPE). A bilateral counter-movement jump (CMJ) test assessed lower limb power performance before and immediately after the match. Fluid loss was determined by body mass weighing before and after the end of the match. T_e and wet-bulb globe temperature (WBGT) parameters were continuously recorded. The matches occurred across T_e ranging from ~20.0 °C to 43.0 °C. Physical demands, CMJ height, peak heart rate (HR_peak), mean heart rate (HR_mean), and RPE were not correlated with T_e. However, a significant correlation was found between fluid loss and T_e (r [95% CIs] = 0.67 [0.43–0.75]; p < 0.001). Beach soccer players maintained physical performance independent of T_e. The specific characteristics of the sport may have promoted adequate thermoregulatory adaptations, helping maintain the players’ physical performance, particularly in matches played under high T_e conditions. Elite beach soccer players maintained their physical performance independently of T_e and despite experiencing dehydration (a body mass decrease of more than 2%) when the T_e exceeded 35 °C. Full article

The assessment of cardiac autonomic regulation (CAR) with non-invasive techniques, such as heart rate variability (HRV), might be of practical interest in elite sports, considering its importance in determining training. We studied 117 soccer players (74 male and 43 female) from three First Division European soccer teams. We used a ranked Autonomic Nervous System Index (ANSI, resulting from the combination of multivariate statistical methodologies applied to HRV-derived indices) to assess CAR. We hypothesized that ANSI might differentiate playing positions, considering goalkeepers, defenders, midfielders, and forwards. We also assessed the perception of somatic symptoms and stress. We observed in male athletes that ANSI was significantly greater in males as compared to females (p < 0.001), being higher in midfielders and defenders (p = 0.035), who usually sustain the greatest external load. Interestingly, this result was not observed in female athletes, who, instead, reported a significantly higher perception of somatic symptoms (p = 0.018) and stress (p = 0.049), the latter being particularly high in midfielders and forwards (p = 0.045). This approach might represent a convenient model to study the effects of long-term physical exercise on CAR in soccer, even to unveil possible differences due to sex, different playing positions characterized by distinct exercise routines, or stress perception. Full article

Background: Soccer is associated with substantial injury risk, with reported between 13 to 35 injuries per 1000 player-hours of competitive play. Notably, approximately 77% of soccer-related ankle injuries are attributed to ankle sprain injuries (ASIs). ASI can lead to chronic ankle instability, obesity, and post-traumatic osteoarthritis. This study focuses on identifying factors such as gender, age, body mass index (BMI), and a history of ASIs, which contribute to the development of ASI in soccer players. Methods: A systematic literature search was conducted in October 2023 across databases, including PubMed, Web of Science, Scopus, Cochrane Library, and ProQuest, without applying any filters. Keywords included ankle, ankle joint, sprain, risk factors, etc. Data extraction was performed on the included studies, with findings standardized and analyzed using Stata Statistical Software: Release 17 to determine a weighted treatment effect. Results: Our systematic review included 26 studies. The meta-analysis revealed that a history of ankle sprain is the most significant risk factor for future ASIs. BMI emerged as a risk factor in three out of seven studies, while age and height were significant in one out of six studies each. Gender and weight were not found to significantly affect ASI occurrence. Other factors identified but not subjected to a meta-analysis due to methodological heterogeneity or insufficient studies included playing surface, joint laxity, muscle weakness, match congestion, strength asymmetries, ground reaction forces, balance maintenance, skill level, and playing position. Conclusions: This research contributes valuable insights into the prevention of ASIs in soccer, highlighting the importance of previous ankle sprains and playing surface quality. These findings assist sports professionals in developing optimal conditions and strategies for effective ankle sprain prevention. Full article

Adductor strains are prevalent injuries in professional soccer. The purpose of this study is to identify further evidence of characteristics associated with adductor injury. MLS and other worldwide leagues have differing styles of play warranting further investigation of injury mechanisms. A descriptive cohort study was conducted with a single professional team in the MLS. Injury data was collected between the 2016 to 2022 seasons to characterize adductor injury. Player position type, age, previous injury, and mechanism(s) of injury (MOI) were assessed to understand the injured population. Generalized estimating equations (GEEs) were utilized to assess the odds of future injury among the injured and non-injured populations. Adductor strains (n = 30) made up 15.5% of all soft-tissue, lower extremity injuries (n = 194) in a single MLS cohort. These injuries were the second most common defined soft-tissue, non-contact injury after hamstring strains (26.4%) and before quadricep strains (11.9%). Among the position types, 28% of defenders, 25% of goalkeepers, 21.4% of forwards, and 20.5% of midfielders experienced at least one adductor strain. The MOI most responsible for these injuries were overuse (30%), change of direction (26.7%), running (13.3%), and kicking (10%). Athletes with previous adductor injury had 167.2 times the odds of adductor injury in a future half-season compared to non-injured athletes. The findings from this study provide further descriptive evidence of player position types and mechanisms related to adductor strain. Insights into the nature of injury within an MLS team and support of previous evidence shows the prevalence of adductor injuries in elite soccer players. Full article