Search Results (120)

Recent advancements in artificial intelligence (AI) have strengthened the interaction between sports and digital technologies. However, unlike widely studied sports such as football and basketball, handball has received limited attention from the scientific community, despite its fast-paced nature and strategic importance. This study focuses on object detection in handball and targets key entities, such as players, referees, goalkeepers, and the ball. A comprehensive dataset was created through a collaborative annotation process, consisting of annotated images extracted from real handball games. The YOLOv8 model was then trained and evaluated on this dataset to assess its effectiveness in entity recognition. The proposed approach achieved an object detection accuracy of 86.8% on a relatively small held-out test set, providing an indicative first benchmark for the application of state-of-the-art machine learning models to handball. To the best of our knowledge, the dataset generated in this study is the first comprehensive collection of annotated handball images, providing a valuable resource for further research. By bridging sports analytics and computer vision, this study contributes to the advancement of performance assessment in handball. These exploratory results suggest potential directions for future real-time systems and practical applications, such as improved understanding of player performance, team dynamics, and strategic decision-making. Full article

Soccer goalkeeper diving saves demand precise inter-segmental coordination to intercept shots under uncertainty, yet preparatory postures and kinematic adaptations between declared (D) and undeclared (ND) conditions remain underexplored in youth athletes. This study analyzed lower-limb kinematics and Continuous Relative Phase (CRP) in 10 elite youth male goalkeepers (14.3 ± 0.3 years) performing dives in different conditions using inertial sensors (Xsens MVN Awinda, 60 Hz) on a natural grass pitch. Data were time-normalized across the dive cycle and analyzed using Statistical Parametric Mapping 1D ANOVA to compare kinematic and coordination differences between conditions and preferred side. ND high dives showed significantly shorter total duration (1.02 ± 0.13 s vs. 1.09 ± 0.12 s) and take-off (0.19 ± 0.05 s vs. 0.21 ± 0.05 s) compared to the D condition. Pronounced laterality emerged in hip internal/external rotation (ipsilateral: 0–100%), with CRP alterations only in the ipsilateral ankle-hip/knee during preferred-side low dives (13–74%, p < 0.001), indicating tighter segmental coupling and reduced phase lag between joints from mid-stance to push-off. D condition appeared to favor mediolateral CoM shifts for reach optimization, while ND emphasized anteroposterior readiness. These findings highlight CRP’s sensitivity to coordination under uncertainty and reveal laterality effects in preferred-side low dives. Full article

This study investigates the performance characteristics of U18 semi-professional soccer players by examining both technical load (TL) and physical load (PL) variables across various playing positions during the 2021/2022 Spanish Football U18 National League Championship. Methods: Principal Component Analysis (PCA) was employed to simplify the dataset, which comprised 246 match records from 49 athletes (mean age 17.9 ± 0.7 years; height ~177.6 ± 6.3 cm; body mass ~72.0 ± 7.2 kg) across ten matches. This analytical approach aimed to facilitate a deeper understanding of player performance dynamics. Results: Kaiser–Meyer–Olkin (KMO) values varied across positions (technical load: 0.20–0.93; physical load: 0.27–0.91). This indicates acceptable sampling adequacy for several positional models, but low adequacy for others; therefore, results for positions with low-KMO values should be interpreted cautiously. Factor analysis for both technical and physical load variables identified two components each, explaining substantial total variance (technical load: 63.75–86.65%; and physical load: 71.74–88.92% across position), with significantly high factor correlations (p < 0.001). The findings further indicate that players occupying defensive positions, such as goalkeepers and center-backs, generally exhibit lower levels of physical intensity and technical engagement compared to their counterparts in more dynamic roles, including full-backs, wingers, and forwards. The latter groups demonstrate higher involvement in high-intensity running and offensive actions. Conclusions: The observed performance patterns highlight the necessity for tailored training programs that align with the specific demands of each playing position. This approach is expected to optimize individual player performance and enhance overall tactical efficiency. Furthermore, the study underscores the importance of developing individualized conditioning strategies that address the unique physical and technical requirements inherent to each role on the field. This analytical approach using PCA provides a more structured and data-driven understanding of these positional differences, reinforming the need for tailored training programs and individualized conditioning strategies. Full article

Background. This study aimed to quantify differences in the internal training load (ITL) of an elite rink hockey (RH) team across days within and between three types of microcycles: pre-season, in-season regular, and in-season congested, to provide insights to optimise microcycle scheduling. Methods. One international-level male RH team comprising seven outfielders (29.6 ± 4.7 years; height, 178.9 ± 2.3 cm; body mass, 77.8 ± 5.7 kg) and one goalkeeper (32 years; height, 180.4 cm; body mass, 83.6 kg) was monitored for 21 microcycles. The ITL was assessed using the session rate of perceived exertion (sRPE) and quantified as time based on a triphasic classification commonly utilised in team sports: low-intensity training (LIT, <80% heart rate maximum (HRmax)), medium-intensity training (MIT, 80–90% HRmax), and high-intensity training (HIT, >90% HRmax). Generalized estimating equations were used to examine differences across within-microcycle training days and between seasonal phases, with linear mixed models applied as sensitivity analyses. Results. Across all phases, significant day-to-day variations in ITL were observed within microcycles (all p < 0.001), with both subjective (sRPE) and objective (LIT–HIT) ITLs progressively decreasing as match days (MDs) approached, showing moderate-to-large population-averaged effects with 95% confidence intervals consistently not crossing zero. The pre-season exhibited the highest overall ITL (p < 0.001), characterised by a substantially greater sRPE and increased time spent across all intensity zones, with the largest magnitudes observed for LIT and MIT compared with the in-season phases. Conclusions. Findings suggest that an international-level RH team progressively reduced the ITL as MDs approached with the highest loads scheduled earlier within microcycles. Moreover, the pre-season had the highest ITLs. This ITL distribution may provide useful guidance for RH coaches and support staff in optimising microcycle planning. Full article

Background: High-intensity physical activity elicits acute physiological responses across the metabolic, cardiovascular, respiratory, endocrine, immune, and neuromuscular systems. During recovery, multiple processes act to restore homeostasis and functional capacity. The aim of this study was to examine age- and position-related differences in cardiovascular and metabolic responses among youth soccer players. Methods: A total of 147 male academy soccer players were assessed, divided into four age groups (U15, U16, U17, U18/U19) and four playing positions (defenders, midfielders, forwards, goalkeepers). Results: Significant anthropometric and physiological differences were observed between age groups. Body height and weight increased progressively with age (p < 0.05), while body fat percentage was lower in younger compared to older cohorts (p < 0.001). Relative muscle mass did not differ significantly between groups. Absolute aerobic capacity (VO₂max) was higher in U17–U19 compared to U15–U16 (p < 0.001). Heart rate at anaerobic threshold (HRAT) and maximal heart rate were greater in the younger groups (p ≤ 0.005). Immediate blood lactate (iBLC) and ΔiBLC were significantly higher in U15–U16 compared to U17–U19 (both p < 0.001). Position-specific analysis revealed higher iBLC in U15 defenders compared to U18/U19 defenders (p < 0.01), whereas no positional differences were observed in relative VO₂max. Conclusions: These results are due to a carefully designed training program and frequent individual training sessions. Full article

This study analyzed penalty kick performance in elite women’s football, focusing on contextual, situational, and technical factors across the Spanish Liga F and the English Women’s Super League during the 2022/23 to 2024/25 seasons. Using an observational methodology, 240 penalties were systematically coded according to twelve criteria and fifty-five categories. Chi-square goodness-of-fit and independence tests were applied to examine distributions and associations. The overall conversion rate was 80.4%, with 15.4% of attempts saved and 4.2% missed. Home teams achieved significantly higher success than away teams (85.6% vs. 72.7%), while penalties taken when leading were less effective (69.9%) compared with those executed while drawing or losing (>84%). Temporal effects were also observed, with lower effectiveness around halftime (71.8%). Laterality and goalkeeper actions showed no significant influence, although some league-specific tendencies were noted. Shot placement emerged as the strongest determinant of success, with upper and central zones achieving near-perfect results, whereas medium-height shots were least effective. These findings extend existing knowledge by providing the first longitudinal evidence from elite women’s domestic leagues in Spain and England. Practical implications include emphasizing accuracy toward optimal zones, reinforcing psychological preparation when leading, and addressing performance drops during specific match periods. Full article

This study analysed how tactical systems and match outcomes influence micro-level passing network metrics across playing positions in a professional football team competing in the Portuguese First Division during the 2020–2021 season. It examined how structural variation affects Degree Centrality, Degree Prestige, and Proximity Prestige across tactical systems (1-4-1-4-1, 1-4-3-3, 1-3-4-3) and outcomes (win, loss, draw) in different positions. Data from 28 league matches were used, with adjacency matrices constructed from teammate interactions. Players were grouped into six positions: goalkeepers, fullbacks, central defenders, central midfielders, wingers, and strikers. One-way ANOVA revealed significant differences (p < 0.05) across positions, tactical systems, and match outcomes. Central defenders consistently showed higher values of Degree Centrality and Degree Prestige across most systems and outcomes, highlighting their structural importance. In contrast, strikers and wingers displayed greater Proximity Prestige in the 1-4-3-3 and 1-3-4-3, reflecting their offensive positioning. Match outcome analysis indicated that wingers had significantly higher Degree Prestige in won matches compared to losses. Overall, results show that micro-level network metrics vary meaningfully by position and context, underscoring the importance of interpreting them cautiously. Despite the novelty of this study, focusing on the initial tactical systems without capturing within-match adjustments may condition the generality of the results. Coaches and practitioners should account for tactical and outcome-related variations when applying network analysis to optimise team dynamics. Full article

Background: Goalkeeper actions directly influence match outcomes and overall team performance. Neuromuscular determinants (e.g., perception–action coupling, reaction speed, rate of force development (RFD), balance, etc.) translate into higher save probability, faster second actions, and more accurate distribution. Objectives: This systematic review analysed neuromuscular performance factors in 11-a-side football goalkeepers and examined how these factors evolve across age and sex groups. Methods: The review adhered to the PRISMA 2020 Statement guidelines. A systematic search was conducted using the PubMed, Web of Science, SPORTDiscus, PsycINFO, Dialnet, LILACS, and Scopus databases. Studies that assessed any aspect of goalkeepers’ neuromuscular performance except for aerobic endurance and VO₂ max (due to the short duration of goalkeeping actions) were included, regardless of the type of observational design. Results: Thirty-five studies were finally included in the synthesis, encompassing neuromuscular performance factors such as agility, speed, anaerobic power, strength, flexibility, and dynamic balance and coordination. The findings underscore the need for neuromuscular training for goalkeepers, particularly agility training. Neuromuscular performance improves with age, especially in linear speed, agility, change-of-direction speed, strength, and power; however, flexibility shows no significant progression. This review identifies key tests for evaluating goalkeepers’ neuromuscular capacities across major performance domains. Conclusions: Although sex differences are apparent, the main limitation is the lack of research on neuromuscular performance in male and female goalkeepers, making it difficult to define indicators for different age and sex categories. Full article

Penalty shootouts often decide major football tournaments, making the analysis of spatial symmetry and shot patterns crucial for performance optimization. This study analyzed 212 decisive penalty kicks in elite men’s football to explore spatial patterns and asymmetries in execution, as well as their relationship with performance effectiveness. An observational methodology was used, combining temporal pattern detection (T-patterns) and chi-square tests to examine associations between contextual, spatial, and outcome-related variables. Results showed that the most frequently targeted area was left-down (28.3%), with a success rate of 71.7%. Additionally, central zones exhibited particularly high accuracy (ranging from 88.9% to 100%) despite their low usage frequency. Differences were also observed in the distribution of shots between left- and right-footed players, both in frequency and effectiveness, although these were not significant. The findings suggest the presence of strategic tendencies and functional spatial asymmetries, which may have implications for specialized training in high-pressure scenarios. These insights can guide targeted training strategies for both kickers and goalkeepers and encourage further research on decision-making and spatial behavior under extreme pressure. Full article

(1) Background: Soccer action recognition (SAR) is essential in modern sports analytics, supporting automated performance evaluation, tactical strategy analysis, and detailed player behavior modeling. Although recent advances in deep learning and computer vision have enhanced SAR capabilities, many existing methods remain limited to coarse-grained classifications, grouping actions into broad categories such as attacking, defending, or goalkeeping. These models often fall short in capturing fine-grained distinctions, contextual nuances, and long-range temporal dependencies. Transformer-based approaches offer potential improvements but are typically constrained by the need for large-scale datasets and high computational demands, limiting their practical applicability. Moreover, current SAR systems frequently encounter difficulties in handling occlusions, background clutter, and variable camera angles, which contribute to misclassifications and reduced accuracy. (2) Methods: To overcome these challenges, we propose TAT-SARNet, a structured framework designed for accurate and fine-grained SAR. The model begins by applying Sparse Dilated Attention (SDA) to emphasize relevant spatial dependencies while mitigating background noise. Refined spatial features are then processed through the Split-Stream Feature Processing Module (SSFPM), which separately extracts appearance-based (RGB) and motion-based (optical flow) features using ResNet and 3D CNNs. These features are temporally refined by the Multi-Granular Temporal Processing (MGTP) module, which integrates ResIncept Patch Consolidation (RIPC) and Progressive Scale Construction Module (PSCM) to capture both short- and long-range temporal patterns. The output is then fused via the Context-Guided Dual Transformer (CGDT), which models spatiotemporal interactions through a Bi-Transformer Connector (BTC) and Channel–Spatial Attention Block (CSAB); (3) Results: Finally, the Cascaded Temporal Classification (CTC) module maps these features to fine-grained action categories, enabling robust recognition even under challenging conditions such as occlusions and rapid movements. (4) Conclusions: This end-to-end architecture ensures high precision in complex real-world soccer scenarios. Full article

Eye tracking and EMG are novel measurement technologies that can be used to assess perceptual processes in sports under real-life conditions. The study was conducted on two groups of soccer goalkeepers (N = 60): Group A—expert goalkeepers (22.8 ± 2.15 years of age; training experience 12.77 ± 3.89 years); Group B—novice goalkeepers (15.70 ± 1.12 years of age; training experience 8.35 ± 2.68 years). Main findings: 1. The elite goalkeepers (Group A) focused most of their attention on only one main object (the foot of the opponent’s kicking leg) compared to novice youth goalkeepers (Group B), whose area of interest consisted of more elements: the knee, the lower leg, the foot of the attacking leg, and the ball. 2. The elite goalkeepers (Group A) showed a significantly shorter decision-making time (240–260 ms) than the novice goalkeepers (290–310 ms) in a two-on-one match situation. 3. The use of anticipatory perceptual skills resulted in more accurate anticipation and decision making in elite goalkeepers than in novice goalkeepers, whose perceptual patterns were more dispersed. 4. The anticipatory activity and structure of bioelectric tensions of the rectus femoris (RF) muscle provide useful information for the development of successful anticipatory actions. The ability to recognize signals is a prerequisite for combining movement sequences according to a predetermined pattern and allows for accurate decision making in the goalkeeper’s playing strategy. Full article

Limited evidence exists on how segmental external load is distributed during linear running and how it varies with speed, training intensity, and individual differences. This study examines the external load profile across six body segments in elite female futsal players during linear treadmill running, focusing on the effects of speed and training zone, as well as individual variability. Eight elite players, including six outfield players and two goalkeepers (mean age 23.9 ± 3.4 years, height 164.96 ± 4.22 cm, body mass 60.31 ± 4.56 kg), performed an incremental test and were measured using six WIMU PRO™ inertial sensors. The sensors recorded segmental PlayerLoad, speed, and training zones. Data were analyzed using Linear Mixed Models. The most important results show significant interactions between body location and speed and between body location and training zone (p < 0.001), with intraclass correlation coefficients (ICC) ranging from 0.437 to 0.515. These results indicate variability among players and specific and asymmetrical segmental load patterns. These findings offer practical insights for tailoring individualized training strategies that optimize performance and reduce segment specific overuse injuries. Full article

This study aimed to describe and assess differences among playing positions, to determine playing position profiles, and to analyze the relationships between the change-of-direction deficit (CODD) percentage and the other anthropometric and performance variables. A total of 98 young futsal players (age: 17 ± 1 years) from the highest national level in Spain were assessed using a cross-sectional design. Anthropometric variables such as height and body mass were recorded. The performance tests included countermovement jumps; horizontal jumps; sprint tests (10 m and 25 m); change-of-direction (COD) tests, including a 10 m test with one COD of 180° (COD180) and a 25 m test with 4 CODs (V-cut); and the percentage CODD. Furthermore, asymmetries were recorded. The group comparisons were considered statistically significant at p ≤ 0.05 and were supported by the effect sizes and mean differences. Significant differences were found among playing positions, showing that pivots and goalkeepers were significantly taller than left- and right-wingers and defenders (p < 0.05, effect size (ES) = −1.42 to 0.72). Goalkeepers were significantly slower than the rest of the positions in COD180 to the left (p < 0.05, ES = 1.32 to 1.89). A very large association was found between the CODDs of 25 m and 25 m (p < 0.001; r = −0.72). These results suggest that pivots and goalkeepers are taller and larger than the other players. However, aside from goalkeepers, no differences in performance variables were observed among the outfield players. In addition, a lower %CODD is associated with a faster COD performance, highlighting its importance in training. Full article

This study investigated the impact of varying the number of small goals on elite female soccer players’ decision-making, technical–tactical skills, running performance, and perceived exertion during game-based situations (GBSs). Sixteen national female players (aged 22.33 ± 2.89 years) participated in three conditions within an 8vs8 game without a goalkeeper (45 × 40 m), each featuring a different number of small goals (1.2 × 0.8 m): (i) 1 small goal (1G); (ii) 2 small goals (2G); and (iii) 3 small goals (3G). Sensors to track players’ positioning, perceived exertion, and notational analysis were used to evaluate player performance. The results indicated that players covered a greater distance at low intensity during the 2G condition compared to both 1G (p = 0.024) and 3G (p ≤ 0.05). Conversely, the 3G condition promoted a higher distance covered at high intensity compared to 2G (p ≤ 0.05). The 1G condition resulted in fewer accelerations (2G, p = 0.003; 3G, p < 0.001) and decelerations (2G, p = 0.012) compared to conditions with additional goals. However, there were no statistically significant effects on technical–tactical actions. Notably, a trend toward improved decision-making was observed in the 1G condition compared to 2G (ES = −0.64 [−1.39; 0.11]) and a longer ball possession duration compared to 3G (ES = −0.28 [−0.71; 0.16]). In conclusion, coaches working with elite female soccer players can strategically vary the number of goals to achieve specific physical aims (i.e., using 2G to emphasize acceleration and deceleration or 3G to promote high-intensity distance) with minimal effects on their perceived fatigue, technical–tactical variables, and decision-making. Full article

Professional training in elite team handball academies is key to developing top players, yet its direct impact on physical performance remains unclear. This study aimed to (1) provide professional training to elite adolescent players and (2) assess performance improvements using a team handball-specific test. Thirty elite male players (six goalkeepers, 24 field players) participated in an 11-week program, with nine under-19 (17.2 ± 1.3 years) and nine under-17 (15.6 ± 0.9 years) field players completing at least 80% of sessions. All underwent pre- and post-testing using the game-based performance test. A two-way ANOVA analyzed differences between tests and age groups as well as playing positions. Significant improvements (p < 0.05) were found in defense and offense time and body weight for both groups. Under-17 players also showed a significant increase in peak oxygen uptake (+9%), ball velocity (+7%), and jump height (+20%). Agility in defense and offense improved in under-19 (+3%) and under-17 (+6%) players, aligning with training goals. Positional differences were observed between backcourt players and wings (p < 0.01) in the ball velocity, while all players showed improvements in both defense and offense performance. We suggest that professional and targeted specific training at this age has a significant impact on the long-term development of adolescent team handball players and is the basis for a professional handball career. Full article