As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases.

Following studies were retrieved for this week:

1 Large-sided games do not replicate the positional worst-case scenarios of official matches in professional football

Reference: Front Sports Act Living. 2026 Apr 2:8:1797322. doi: 10.3389/fspor.2026.1797322. eCollection 2026.
Authors: Lukas Herzig, Jörg Stöckert, Matthias Lochmann, Michael C Rumpf
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13083062/pdf/fspor-08-1797322.pdf
Summary: The aim of this study was to determine if positional Worst-Case-Scenarios (WCS) during official games (OG) are replicated in Large-Sided Games (LSG) with a similar Area per Player (ApP) as OG. Twenty-one football players from the second team of a professional German football club were monitored during OG and LSG. WCS of 1 min (WCS1), 3 min (WCS3), and 5 min (WCS5) were calculated for OG and LSG using rolling average methods for Total Distance (TD), Medium-Speed-Running (MSR), High-Speed-Running (HSR), and Sprint Distance (SPD), in addition to low-, medium-, and high-intensity Accelerations (ACC1, ACC2, ACC3) and Decelerations (DEC1, DEC2, DEC3). LSG displayed significantly lower values (p < 0.05) for TD, MSR, HSR, and SPD for all positions compared to OG. ACC1-3, and DEC1-3 were also significantly (p < 0.05) lower in LSG compared to WCS in OG, with exceptions observed for Full Backs (FB) in ACC1 (WCS3), ACC3 (WCS1, WCS3, and WCS5), and DEC1 (WCS3); for Strikers (ST) in ACC1 and DEC1 (WCS3 and WCS5); and for Central Midfielders (CM) in ACC2 (WCS3). These findings suggest that LSG are not suitable for replicating OG‘ WCS1, WCS3, and WCS5. Coaches should therefore supplement with running-based drills or adjust training games to ensure that WCS demands are met.

2 National health registries in professional German football: development and first results from the men’s and women’s 1st and 2nd Bundesliga

Reference: BMJ Open Sport Exerc Med. 2026 Apr 10;12(2):e003003. doi: 10.1136/bmjsem-2025-003003. eCollection 2026.
Authors: Lorenz Huber, Dominik Szymski, Werner Krutsch, Johannes Weber, Gunnar Huppertz, Florian Zeman, Michael Koller, Micha Pietzonka, Christian Klein, Andreas Nagel, Volker Alt
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13084848/pdf/bmjsem-12-2.pdf
Summary: Long-term, nationwide data on injuries and illnesses in professional football, particularly in women, remain limited. This study aimed to describe injury and illness epidemiology in German professional male and female football using prospective registry data, with a focus on incidence, distribution, and return-to-play times and on sex-specific differences. Two prospective registries were introduced in the first and second divisions of German professional football (men: 2022/2023, women: 2023/2024). Team medical staff reported all time-loss injuries and illnesses using a standardised, pseudonymised protocol on an online platform. Data included diagnosis, injury mechanism and return-to-play data. Injury and illness match incidence was calculated per 1000 hours of match exposure. A total of 1514 players (963 men, 551 women) from 54 teams participated. During the first season, 1185 time-loss events were recorded (men: 503 injuries, 176 illnesses; women: 362 injuries, 144 illnesses). In men, the most affected areas were the thigh, ankle and knee, whereas in women, injuries predominantly affected the knee, followed by the ankle and thigh. Ankle sprains were the most frequent injury type in both sexes. ACL ruptures were associated with the longest return-to-play times, particularly in female players. Illnesses caused 3188 absence days in total, mainly due to respiratory infections. The registries reveal clear sex-specific differences in injury distribution and time-loss in German professional football and demonstrate a substantial burden of illness-related absence. These nationwide data provide a foundation for longitudinal monitoring and future research on sex-specific prevention and return-to-play strategies.

3 Incidence and risk factors of spondylolysis in youth football: a longitudinal study among male Norwegian players

Reference: BMJ Open Sport Exerc Med. 2026 Apr 9;12(2):e003222. doi: 10.1136/bmjsem-2026-003222. eCollection 2026.
Authors: Nicolay Morland, David Tovi, Benjamin Clarsen, Cecilie B Rygh, Lena Kristin Bache-Mathiesen, Hege Havstad Clemm, Hilde Gundersen
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13084936/pdf/bmjsem-12-2.pdf
Summary: Spondylolysis is a common source of low back pain (LBP) among adolescent athletes. We aimed to investigate the occurrence of LBP and spondylolysis, and the potential associations of weekly training and match exposure, and maturity status with spondylolysis among male youth football players. Male players (n=98) from six teams were followed over three consecutive seasons (U15-U17). Training and match exposure (min), and pain/injuries were self-reported weekly. Clinical examinations were conducted if a player reported LBP and abstained from football training/matches for 1 week or reported LBP for 4 consecutive weeks despite participating. MRI was used to determine if the LBP was due to spondylolysis. The maturity level was estimated biannually by X-ray of the left hand, along with body height and weight. Risk factor analyses estimated the association between an increase in total weekly training and match exposure and the risk of spondylolysis, and between maturity factors and the risk of spondylolysis. Of 98 players, 46 reported back pain at least once, 18 fulfilled the criteria for a clinical examination and 13 underwent an MRI scan, identifying 12 cases of spondylolysis. Risk factor analyses showed a significant association between increased total weekly training and match exposure and the risk of spondylolysis. No association was shown between any maturity measure and the occurrence of spondylolysis. Increased training and match exposure in the weeks before injury was significantly related to a diagnosis of spondylolysis. Maturity measures were not related to increased risk.

4 The Effect of Walking Football on Physical Fitness and Psychosocial Health in Hong Kong Adults Aged 50+: A Mixed-Method Study

Reference: J Aging Phys Act. 2026 Apr 20:1-13. doi: 10.1123/japa.2024-0401. Online ahead of print.
Authors: Ming Yu Claudia Wong, Kai-Ling Ou, Ka Man Leung, Shali Wang
Summary: This study examined the effectiveness of a walking football program on physical fitness, football skills, and psychological outcomes among adults aged 50+ in Hong Kong. A total of 521 older adults (40% female) participated in the walking football program. Participants were required to attend an 8-week beginner class upon enrollment, with the option to progress to an advanced class in a subsequent 8-week stage. Three groups were identified: (a) participants who only engaged in the 8-week beginner class (Pre-8B-Post), (b) participants who only engaged in the 8-week advanced class (Pre-8A-Post), and (c) participants who engaged in both the beginner and advanced classes (Pre-8B-8A-Post). Physical fitness was assessed using the Senior Fitness Test, and football skills were measured using a short passing test. Psychological outcomes, including symptoms of depression, resilience, mindfulness, social networks, exercise self-efficacy, and general health, were evaluated using validated questionnaires. In addition, 11 focus groups (five to six participants each) were conducted using a semistructured interview guide based on the RE-AIM framework to explore participants‘ qualitative experiences and benefits. Participants in advanced or combined beginner and advanced classes demonstrated greater improvements in visceral fat, arm curl, and the 8-ft up-and-go test compared with participants in beginner-only classes. Combined-class participants also showed significant gains in mindfulness and social networks, whereas single-class participants reported greater improvements in resilience, exercise self-efficacy, and general health. Qualitative findings highlighted benefits in physical and mental health, social connections, and physical literacy.

5 Physical performance responses to match venue and outcome in elite soccer

Reference: BMC Sports Sci Med Rehabil. 2026 May 2. doi: 10.1186/s13102-026-01723-8. Online ahead of print.
Authors: Hadi Nobari, Okan Kamis, Ali Rıza Atıcı, Armin Gorouhi, Gizem Baskaya, Leandro Henrique Albuquerque Brandao, Gibson Moreira Praça
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01723-8_reference.pdf
Summary: It is widely accepted that match venue influences technical, tactical, fitness, nutrition, the importance of the match, sleep, and psychological factors. This study investigates the impact of match venue (i.e., home vs. away) and match outcome (i.e., win, draw, or loss) on performance metrics among Turkish Super League teams. Utilizing a Generalized Linear Model (GLM) approach, we analyze performance indicators such as total distance covered, distance covered at different speed intervals, and number of sprint efforts (> 7 m·s⁻¹). Considering the total distance covered, the GLM showed no significant effects of match venue [Wald (1,625) = 0.398; p = 0.528], match outcome [Wald (2,624) = 3.413; p = 0.181], and interaction between the factors [Wald (2,624) = 0.477; p = 0.788]. Significant effects were observed in the distance covered at speeds over 7 m·s⁻¹. In conclusion, the match venue does not impact physical performance. At the same time, winning teams display higher distances covered at higher speeds and perform more sprint efforts (> 7 m·s⁻¹), indicating that physically outperforming opponents is relevant for winning in elite soccer.

6 Manipulating player numbers in small-sided soccer games: effects on numerical superiority and inferiority across physiological, physical, technical, and tactical performance

Reference: Front Sports Act Living. 2026 Apr 15:8:1813770. doi: 10.3389/fspor.2026.1813770. eCollection 2026.
Authors: Michael C Rumpf, Johannes Jäger, Rhodri S Lloyd, Matthias Lochmann
Download link: https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2026.1813770/full
Summary: Small-sided games (SSG) are widely used in soccer training to replicate the physiological, physical, technical, and tactical demands of competition within representative contexts. Coaches often manipulate task constraints by creating numerical superiority or inferiority, which imposes specific demands and elicits targeted adaptations. This review aimed to synthesize the effects of numerical imbalances on player performance across physiological, physical, technical, and tactical domains. Evidence indicates that playing in numerical superiority consistently reduces physiological intensity (e.g., mean heart rate, time >90% HRmax) and high-intensity physical load (e.g., total distance, sprinting, accelerations), while increasing low-intensity activity such as walking. Oppositely, technical performance improves, with a higher number of passes and overall actions. Tactical behavior also adapts, with teams expanding playing length and width, covering more space near the opposition goal, and increasing attacking opportunities, while exploratory behavior and proximity to their own goal decrease. Conversely, teams in numerical inferiority adopt compensatory strategies, focusing on defensive organization and goal protection, which can reduce physical output and exploratory movement, particularly under high-inferiority conditions. Numerical imbalances in SSG seem to modulate physiological load, physical activity, technical execution, and tactical behavior. These findings provide a framework for optimizing training design and session planning in soccer, enabling coaches to manipulate player numbers to target specific performance outcomes.

7 Change of direction and deceleration deficits in adolescent male soccer players at different maturity levels

Reference: BMC Sports Sci Med Rehabil. 2026 Apr 30. doi: 10.1186/s13102-026-01697-7. Online ahead of print.
Authors: Volkan Sert, Ayşenur Turgut Kaymakçı, Ertuğrul Gelen, Suat Yildiz
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01697-7_reference.pdf
Summary: Change of direction and deceleration are crucial for soccer performance. However, these abilities may be influenced by growth and maturation during adolescence. Understanding these effects is essential for optimizing training and potentially mitigate injury risk in young players. This study aimed to evaluate the effects of maturation on change of direction (COD) and deceleration performance in adolescent male soccer players with varying levels of maturity. Ninety-four adolescent male soccer players (age 13.2 ± 1.9 years) participated in this cross-sectional study. The participants were divided into three groups based on their biological maturity levels: pre-PHV, circa-PHV, and post-PHV. Over a ten-day period, familiarization, determination of maturity status, and 15-meter linear sprint and 505 agility test protocols were implemented. COD and deceleration deficits (DD) were calculated and analyzed. Significant differences were detected among the maturity groups for 10m and 15m linear sprints, dominant and non-dominant directions in the 505-agility test, and full approach (p<0.001; η²p: 0.58-0.81). Notably, strong correlations were found between 505 COD performance and linear sprint times in the pre- and post-PHV groups, whereas no such correlation was observed in the circa-PHV group. Furthermore, deceleration ability exhibited a significant correlation with 10m sprint performance; however, no significant relationship was identified with 15m sprint performance. The results suggest that maturity level significantly affects COD and deceleration performance in adolescent male soccer players. Coaches and performance specialists should design individualized training programs tailored to the developmental stages of young athletes to enhance performance and potentially mitigate injury risk.

8 Neural efficiency in creative decision-making: a sparse directed subnetwork in soccer experts revealed by fMRI

Reference: Neuroimage. 2026 Apr 28:121961. doi: 10.1016/j.neuroimage.2026.121961. Online ahead of print.
Authors: Mohammad Rezaei, Asghar Zarei, Alireza Talesh Jafadideh
Download link: https://pdf.sciencedirectassets.com/272508/1-s2.0-S1053811926X20079/1-s2.0-S1053811926002764/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEIb%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCIQDX1mnQRV3c4mOcFUrz9j1BSDKnj3iHzNqx08f%2BiNw0MwIgeWeBUOSKxjPBcw69uAcT2eERCR8%2FjSzc8HoagTjaYpcqsgUIThAFGgwwNTkwMDM1NDY4NjUiDK1iwczhYTtQCvrZASqPBXeHV3qQt%2FrMRDcWDKWorKKvaKuuwFSKcHtERmy0jTmVZg8QyRuIuozRPIPcLtTeo9Yr0cb3Ym4WRM5DBUHXkyRe%2FJ2dbzvPmqBsfdUcOBYQeltdD6gIMRr7DQSvUuMtuOJg0yyHlj5%2Bgk1P%2BnhIywhr9%2FiMJgwmOdcdAoYKaOnKLCyeKvVD%2FR4o5bgJ1FFs8cFKpKT8HIQwN46tI8O1s9%2BrWebjiHCMmoL5P%2FnoUoMx5Tgg5b6WvnjLqoBCfLCL7kjwU%2Bi%2BZJg8yaExwR45XVHZ6Sicn8%2FbbG83%2BB%2FoJm%2BbqWkjYnGVRaYccWvyomMqpC%2FCGQ0hU05Gey3EkTUgJteW8gspoMTxOKINvNqTNz002nAr5IglpOfT5iUdai8zvI8J8TAk7ZeNWmYxw0a8Aswy98Ga69up3OMWH4CDozGCB2h9dxHIzkbvd%2BGArJXXjJzKFndZvkivCSu%2BIsK90gcnkSzq0%2Fo70TbLlY0tBWll%2FD0pLtHYNgO9%2FjjdCGLXh2JwhSY%2BgWTBDuqrfXLzlagtwbDgAavBUlLOvjslgnRWbp3Olf1CnApCweiGszuowxi%2B8SsBjK93h2Ahmwn0YbSmwspJury5lOpGhSSH68F8Z1Y%2B0x6GDpBFcQ8%2FjtBfxnrMy5OP8oTXFPX556CmvO%2BwbvM%2Bnm6JztbDm1XekuPMWOqgYPggwHgaIB7jLwWuo%2FJpVUFVlWzGDnLzkBcz7SmD%2B%2F6nwLti7%2BZKOSAfk%2BW%2BKe3%2BGpVfMozWfSJo44SryLapafv7T01U2WNqLeYfTNeEebsNcs0EaBn9xckKO9ofDzZ%2BHD9YnEoFj0AEgLmRck%2Fd74MRHMbIMtXHrhWSiyjFfYPNb8D2n3nXgqMLfwMw%2Bq%2FbzwY6sQFVvQAljVJrIevZvXwePHEQHVd1D65YCEZs6OCc4BgC3N19LXPdxvgqGk%2FWvbbBQnhpLsSjpwVOvqnOZkAtx3wmmpRBEPdsXkGhVFhNcxkutdDsy453bO3nx4t%2FKrEaYiWIHc9TjrKzYD1mywBvQgMpSvtfAqFOV3qOQx5aue%2FBgzFnGX2HMJW%2B2s46sKf8Kf5RAbdIi%2F87DCSQHw0y2pSnTPWyYjhvbXoVhwsxDsFir5I%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20260503T063645Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYR3BMOFV6%2F20260503%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=02a22378728ba2fde5105ce2fc326420ab16bb874f7e26c9337eecdbd6e3242c&hash=235be71b2c13b39290de982479ccc13da2fbd802ec1f159ca456761931115879&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S1053811926002764&tid=spdf-233acfdd-9803-4c6a-8aa7-73a26e0f9358&sid=ac35d39a310af94ede69c426a397b985d04cgxrqa&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&rh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=1e005e045603505e0d0a54&rr=9f5d40cd0c58e7ba&cc=de
Summary: Creative choices often require quickly generating and evaluating possible actions under time pressure. However, it is still unclear whether creative continuation is expressed as a directed reconfiguration of whole-brain communication beyond undirected coupling or isolated regional responses. In this study, we identify directed, multiscale network signatures that separate creative from obvious action continuations in a naturalistic soccer decision task and measure how these patterns relate to creative decision skills. We estimated directed effective connectivity among 112 regions from whole-brain fMRI during Think (creative continuation) versus Video (obvious continuation) trials and tested condition effects using nonparametric permutation inference with family-wise error (FWE) control, and network organization was summarized using triad motifs and community structure, and related to Soccer Video Test scores (SVT). Twenty-two directed connections showed Think-Video differences at FWE α=0.05 in the 33 participants with usable data in both conditions. Think increased network description length (ρ=0.05: 6.20 vs 5.72; t32=6.23; PFWE=0.0001) and reduced feedforward-closure and convergent fan-in motifs (t32=-4.59 and -4.66; PFWE=0.0013). Across players, higher SVT scores predicted higher convergent fan-in motif counts (021U) (β=0.35 to 0.40; p=0.006 to 0.016; q≤0.047) and lower description length (β=-0.32 to -0.37;p=0.014 to 0.035; q≤0.047). Collectively, these findings demonstrate previously unresolved directed reweighting of local motifs and mesoscale organization during creative continuation, and provide a framework for mechanistic tests of creative expertise in real-world decisions.

9 Transfer of Technical and Tactical Skills from Futsal to Soccer: A Systematic Review and Meta-Analysis of the ‚Donor Sport‘ Concept

Reference: Percept Mot Skills. 2026 Apr 29:315125261449162. doi: 10.1177/00315125261449162. Online ahead of print.
Authors: Erwin Farid Peña-Ardila 1
Summary: The „donor sport“ concept proposes that engaging in futsal can facilitate the acquisition of transferable skills for association football (soccer), consistent with ecological dynamics perspectives on constraint-led learning. To identify, evaluate, and synthesize scientific evidence regarding the transfer of technical, tactical, and perceptual-motor skills from futsal to soccer. A systematic review following PRISMA 2020 guidelines (Page et al., 2021) was conducted across three electronic databases (Scopus, ScienceDirect and Web of Science Core Collection) up to November 2025. Original studies reporting quantitative data relevant to futsal-to-soccer transfer were included. Seven studies were included (N = 7). The meta-analysis revealed a very large effect size favoring futsal-based constraints for passing accuracy (SMD = 1.43; 95% CI: -0.16 to 3.03). For time-based perceptual-motor outcomes, the pooled estimate was non-significant and highly heterogeneous; field-based reactive tasks tended to favor futsal, whereas isolated laboratory tasks tended to favor soccer. Current evidence supports the use of futsal as a potent medium to accelerate the acquisition of technical passing precision. However, the transfer of speed and agility appears to be highly dependent on context and task specificity.

10 Evaluating burnout of soccer players with respect to their positions

Reference: Front Psychol. 2026 Apr 13:17:1781981. doi: 10.3389/fpsyg.2026.1781981. eCollection 2026.
Authors: Mine Taskin, Halil Taskin
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13111085/pdf/fpsyg-17-1781981.pdf
Summary: Athlete burnout is a common negative psychological state of athletes, which includes physical/emotional exhaustion, diminished personal accomplishment, and negative evaluation of sports. The aim of this study is to examine the burnout dimensions in amateur football players according to playing positions. A total of 113 amateur soccer players participated in the study (age range: 20-35) and the mean (SD) weight was 74.81 ± 8.41 kg, height was 179 ± 2.56 cm. An Athlete Burnout Questionnaire was used to determine the athlete burnout dimensions of soccer players. The results of study show that the data revealed the defense players had higher values in the two subscales: emotional/physical exhaustion (EPE) and sport devaluation (SDeval). On the other hand, the strikers had higher values in the reduced sense of accomplishment (RSA) subscale. Based on the indicators of burnout dimensions, goalkeepers, midfielders, and forwards appear to make adequate psychophysiological adjustments to the demands of competition regarding physical and emotional exhaustion and sport devaluation. In terms of reduced sense of accomplishment, goalkeepers, defenders, and midfielders demonstrate sufficient psychophysiological adaptation to competitive demands. The impact (preventing goals and scoring goals) represented by defenders and strikers with higher burnout scores should be investigated.

11 Strength and Power Responses to a Power-Oriented Resistance Training Model across an Entire Soccer Competitive Season

Summary: J Hum Kinet. 2026 Apr 2;101(Spec Issue):245-255. doi: 10.5114/jhk/218820. eCollection 2026 Feb.
Authors: Renan F H Nunes, Lucas A Pereira, Juan P Fiorenza, Carlos A Paes, Rafael Grazioli, Piotr Bryk, Irineu Loturco
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13112153/pdf/JHK-101-218820.pdf
Summary: This study investigated longitudinal changes in strength- and power-related performance across an entire competitive season in elite soccer players using a frequent and systematic monitoring approach. Twenty-three professional players competing in the Brazilian first division were monitored over seven consecutive months. Athletes performed two to three resistance training (RT) sessions per week, with one weekly „control“ session used to adjust training loads and assess neuromuscular status through bar-derived measures obtained in the half-squat exercise. Relative power (RP), relative strength (RS), and estimated one-repetition maximum (1RM) were recorded across 28 training sessions using the load associated with maximum power output. Weekly variations were analyzed using a 4-week rolling average, and pre-, mid-, and post-season periods were compared using repeated-measures ANOVA. Across the season, RP, RS, and 1RM exhibited a gradual and consistent positive trend. While only isolated meaningful changes were detected when individual sessions were compared with rolling averages, significant improvements were observed at the post-season time point compared with both pre- and mid-season values (p < 0.05). Notably, despite a modest ~5% increase from pre- to post-testing, absolute training loads did not change significantly across the season, indicating that performance gains were achieved without meaningful increases in training load magnitude. These findings demonstrate that a power-oriented RT model, supported by continuous monitoring and load adjustments, can effectively preserve and enhance strength and power throughout a competitive soccer season. This approach appears to mitigate commonly reported in-season declines in neuromuscular performance and offers a practical strategy for managing RT under congested competitive schedules.

12 Multifactorial Thresholds of Psychomotor Fatigue in Soccer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Reference: J Hum Kinet. 2026 Apr 2;101(Spec Issue):49-71. doi: 10.5114/jhk/212912. eCollection 2026 Feb.
Authors: Moses Gnanasigamani, Jennifer M Kiruba, Paweł Chmura
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13112161/pdf/JHK-101-212912.pdf
Summary: The present study addressed the complex nature of fatigue in soccer, examining its physical, psychological, neuromuscular, and metabolic dimensions. It evaluated the impact of these different types of fatigue on players‘ performance, highlighting the importance of comprehensive fatigue-management strategies for enhancing performance and reducing injury risk among soccer players. The primary aim of this study was to investigate the effects of various types of fatigue on performance of male soccer players across different competitive levels, through a systematic review and meta-analysis of randomized controlled trials. A total of 37 randomized controlled trials involving male soccer players were included, following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to assess the multifaceted impacts of fatigue. Key findings revealed that neuromuscular fatigue had the highest mean effect size (0.63), with substantial consistency across studies (95% CI: 0.45-0.80, I2 = 99.79%). Physical and metabolic fatigue both showed a mean effect size of 0.38, though they differed in variability; metabolic fatigue demonstrated considerable heterogeneity (I2 = 98.73%), reflecting diverse physiological responses, while physical fatigue showed moderate consistency (I2 = 98.20%). Psychological fatigue had a significant impact on performance (mean effect size: 0.57), with variability (I2 = 97.08%) suggesting context-dependent effects. These results underscore the necessity of a multimodal approach that integrates physical, metabolic, neuromuscular, and psychological interventions to optimize soccer performance and mitigate injury risk. Practical implications include the adoption of targeted recovery strategies such as inter-set recovery intervals and whole-body vibration techniques, as well as the implementation of mental resilience and cognitive training to manage psychological fatigue. Such strategies are essential for developing individualized training and recovery protocols that enhance athletic performance and support long-term career sustainability.

13 You Play the Way You Train: The Influence of Accumulated Weekly Training Loads on Match Physical Performance in Soccer Players

Reference: J Hum Kinet. 2026 Apr 2;101(Spec Issue):5-20. doi: 10.5114/jhk/208874. eCollection 2026 Feb.
Authors: Iván Asín-Izquierdo, Carlos Galiano, Fabio Y Nakamura, Fernando H Pareja-Blanco, Clemente Jose A Asian-
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13112165/pdf/JHK-101-208874.pdf
Summary: The relationship between soccer players‘ match performance and cumulative training loads needs to be analysed. Therefore, the objectives of this study were: 1) to examine the influence of accumulated weekly training loads on subsequent mechanical match outcomes, and 2) to analyze individual variability in training and match loads using the coefficient of variation (CV) throughout the season. Internal and external loads over the entire season of 22 semi-professional soccer players (age 23.2 ± 4.2 years, body mass 75.0 ± 5.8 kg, and body height 1.79 ± 0.06 m) were analyzed. The devices used were 10-Hz Playertek+ GPS/GNSS units equipped with an inertial system and an accelerometer (Catapult Innovations, Melbourne, Australia) and the Borg scale in its 6-20 points version. The analysis of the data with the entire squad included all demarcations (except goalkeepers), however, in a second analysis players with the highest participation throughout the season were included, i.e., six defenders (three center back and three fullback players), three midfielders and three forwards (two wingers and one striker). Match high-speed running (HSR) showed significant correlations with most of the variables analyzed (r = 0.14-0.52). Training load variables analyzed (14.7-64.5%) exhibited larger CV values than those observed in matches (4.4-31.8%). Players with greater match HSR showed superior accumulated HSR during the week before the match than those who presented less match HSR (p = 0.024). The cumulative training load indicates a direct relationship with match HSR performance acutely and chronically. Thus, coaches should design tasks emphasizing HSR accumulation throughout the season.

14 The dRM-Index: Applicability of the Differential Respiratory-to-Muscular Training Load Index in Young Female Soccer Players

Reference: J Hum Kinet. 2026 Apr 2;101(Spec Issue):73-86. doi: 10.5114/jhk/211330. eCollection 2026 Feb.
Authors: Arrizabalaga Oihan Esnal-, Tabar Ibai Garcia-, Artetxe Asier Gonzalez-, Asier Los Arcos
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13112166/pdf/JHK-101-211330.pdf
Summary: This study described the differential respiratory and muscular perceived training loads (RPEres-TL and RPEmus-TL) within and between sessions, and investigated the associations between neuromuscular performance and the dRM-Index (i.e., the ratio of differential respiratory and muscular perceived training loads: RPEres-TL divided by RPEmus-TL) among youth female soccer players. Thirteen outfield players (age: 17 ± 1 years) of the third team of a Women’s Soccer Spanish First Division Club completed the 14-week study period. Neuromuscular performance tests (countermovement jump [CMJ], CMJ arm swing, single leg CMJ, and 30-m sprint tests) were conducted before (T1) and after (T2) the study period. Players improved neuromuscular performance (p < 0.05; Cohen’s d < 1.29; small-to-large) from T1 to T2. RPEres-TL was greater than RPEmus-TL for training sessions performed four (M-4: p < 0.001; Cohen’s d = -0.61; moderate) and one (M-1: p = 0.01; Cohen’s d = -0.37; small) days before the match. Baseline sprint performance showed large correlations with the dRM-Index during M-2 (p < 0.05; r < 0.59), M-1 (p < 0.05; r < 0.60) and matches (p < 0.05, r < 0.66). Differential RPE allows the analysis of the TL distribution during the week providing additional insights into the training workload. Baseline sprint performance can be used to forecast the differed heterogeneous individual cardiovascular and neuromuscular responses to the sessions. This initial study on the dRM-Index offers a novel and practical approach to individualize and optimize the training process of youth female soccer players.

15 The effects of fatigue on the relation between ocular pursuit and interceptive performance in soccer experts

Reference: J Sports Sci. 2026 Apr 28:1-18. doi: 10.1080/02640414.2026.2653298. Online ahead of print.
Authors: Jost Hausendorf, Claudia Gonzalez, Jaida Leone Lewis, Mark Rakobowchuk
Summary: Accuracy and duration of ocular pursuit of a target object have been linked to interceptive performance. Yet, previous assessments have not examined this relationship in the context of fatigue. We assessed the relationship between ocular pursuit and interceptive performance under peripheral and central + peripheral fatigue conditions. We determined ventilatory thresholds in n = 17 soccer experts using a ramp incremental protocol to individually tailor 45 minutes of cycling in the heavy exercise domain. Throughout the central + peripheral fatigue exercise, participants completed a modified Stroop task, known to induce subjective central fatigue and task performance decrements after 45 minutes. We used mobile eye-tracking to measure ocular pursuit accuracy and duration, and two external cameras to determine 3D positions of the ball and foot during an interceptive soccer task before and after exercise using deep learning algorithms. Using linear mixed models, we found a positive relationship between ocular pursuit accuracy and interceptive performance on a trial-by-trial basis before exercise. This relationship disappeared following exercise, suggesting a fatigue-driven change in gaze strategy. Despite this change in the gaze-performance relationship, interceptive performance on the soccer-specific task was maintained after exercise irrespective of addition in exercise cognitive demands.

16 Key indicator for winning soccer matches: net efficiency

Reference: BMC Sports Sci Med Rehabil. 2026 Apr 28. doi: 10.1186/s13102-026-01717-6. Online ahead of print.
Authors: Yue Zeng, Xiao Xie, Hui Zhang
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01717-6_reference.pdf
Summary: Current soccer match analysis focuses predominantly on team tactics and technical aspects, such as offensive and defensive strategies and their transitions. However, match efficiency has received limited attention, making it difficult to explain scenarios where a team dominates possession but fails to secure victory. This study introduced the concept of soccer match efficiency and proposed computational formulas for offensive efficiency (OE), defensive efficiency (DE), and net efficiency (NE). Using data from the Chinese Super League (CSL) between 2014 and 2019, we analyzed NE as a metric for evaluating the balance between a team’s offensive and defensive performance. Net efficiency effectively reflected the balance between offensive and defensive performance and elucidated the phenomenon of “dominating possession but failing to score.” In the CSL: (1) an NE ≥ 0.2 corresponded to an 80.62% win probability; (2) an NE between 0.1 and < 0.2, 64.38%; (3) an NE between 0 and 0.1, 46.07%; (4) an NE of 0, 0%; (5) an NE between − 0.1 and 0, 24.69%; (6) an NE between − 0.2 and − 0.1, 11.25%; and (7) an NE ≤ -0.2, 5.38%. (1) Net efficiency showed a clear positive association with match outcomes, with higher NE values corresponding to higher winning rates. (2) Net efficiency provided a quantitative measure of offensive-defensive balance and offered a clearer explanation for why teams may dominate possession yet lose.

17 Rates of physical contacts, headers, ball flight occurrences, and suspected concussions in Canadian adolescent soccer: Headed for injury prevention

Reference: J Sci Med Sport. 2026 Apr 15:S1440-2440(26)00142-8. doi: 10.1016/j.jsams.2026.04.003. Online ahead of print.
Authors: Kenzie B Friesen, Matthew G Neill, Tuija A Hyyrynen, et al.
Download link: https://www.jsams.org/action/showPdf?pii=S1440-2440%2826%2900142-8
Summary: The aim was to examine physical contact, head contact, header, and ball flight rates, video-suspected concussion and musculoskeletal injury between match structures (indoor and outdoor), across age (U15 and U17 players) groups and sexes (males and females). Youth soccer players (aged 13-18) competed in the 2022-2023 indoor (N = 10 matches) and outdoor (N = 10 matches) seasons. Sex (male vs. female), age (U15 vs. U17), and structure (9v9 vs. 11v11) were considered. Physical contacts (player-to-player), headers (head contact with the ball), ball flight occurrences, and video-suspected concussion and musculoskeletal injuries were coded via video-analysis in 20 adolescent soccer matches. Overall, 5547 total physical contacts and 874 headers (362M; 512F) were coded. Average marginal effects demonstrated higher header rates for males (incidence rate ratio = 1.52, 95 % confidence interval: 1.32-1.76) and 9v9 (incidence rate ratio = 1.78, 95 % confidence interval: 1.53-2.06) compared to females and 11v11. Mean marginal effects also demonstrated a lower rate of physical contacts for males (incidence rate ratio = 0.95, 95 % confidence interval: 0.90-1.00) compared to females and a higher rate of physical contacts in 9v9 (incidence rate ratio = 1.68, 95 % confidence interval: 1.59-1.78) compared to 11v11. Rates of ball flight occurrence were higher for males (incidence rate ratio = 1.54, 95 % confidence interval: 1.34-1.78), indoor play (incidence rate ratio = 1.41, 95 % confidence interval: 1.59-1.78), and at U17 (incidence rate ratio = 1.43, 95 % confidence interval: 1.23-1.64), compared to females, outdoor, and U15, respectively. Female matches were associated with a higher rate of video-suspected musculoskeletal injury (incidence rate ratio = 1.94, 95 % confidence interval: 1.11-3.39) compared to males (total MSK: 35M, 19F). There were 9 suspected sport-related concussions (5M; 4F). Future research attempting to quantify or alter header exposure in adolescent soccer should consider the influence of match structure, age group, and sex of players.

18 Implementing a Two-Season Traditional Strength Training Intervention: Chronic Adaptations in Physical Fitness and External Match Demands of HighPerformance Female Youth Soccer Players

Reference: Res Q Exerc Sport. 2026 Apr 27:1-8. doi: 10.1080/02701367.2026.2659831. Online ahead of print.
Authors: Sefika Pelin Bal, Javier Raya-González, Luis Manuel Martínez-Aranda
Summary: This study aimed to analyze the impact of a long-term traditional strength training intervention across two full competitive seasons to evaluate physical fitness performance and external match demands in highperformance female youth soccer players. Twenty-eight Danish female young highperformance soccer players (age: 16.5 ± 0.8 years), belonging to two different soccer teams competing at the highest level for their age, participated in the study. Teams were allocated to either an experimental group, performing twice-weekly strength training for 2 years (EG, n = 14) or a control group (CG, n = 14). Physical fitness level, including vertical jump performance and Yo-Yo IR2 performance for maximal oxygen uptake (VO2max), was assessed at four different time points: at the beginning of season 1; at the end of season 1; at the beginning of season 2; and the end of season 2. Additionally, players‘ match external demands (i.e. total distance, distance covered at speeds above 23 km·h-1, and maximum velocity achieved) were monitored using Global Positioning System devices during four matches before and after the intervention, in the same 4 time-points. Experimental group players obtained greater improvements in both physical fitness and external match load performance, compared to the players in the control group, showing enhancements in all comparisons along the time-points (p < .05 to p < .001). These findings support the inclusion of strength training as an essential part of female soccer players‘ periodization, not only to improve their performance, but also to facilitate their transition to professional soccer.

19 The Influence of Body Fat Percentage on Physiological Responses and Performance in Professional Soccer Players During a Soccer Game Simulation Protocol on a Treadmill

Reference: Sports (Basel). 2026 Apr 15;14(4):156. doi: 10.3390/sports14040156.
Authors: Marios Hadjicharalambous, Andreas Apostolidis, Nikolaos Zaras, Eleanna Chalari, Tooba Tooba, Rabia Faiz, Omid Razi
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13120111/pdf/sports-14-00156.pdf
Summary: This study examined whether different body fat percentages (BF%) may influence performance, physiological responses, and fatigue in professional soccer players during a simulated soccer game protocol on a treadmill. Twenty professional male soccer players were categorized in higher (HBF%) and lower (LBF%) body fat percentage groups [HBF% > 11.5%; n = 11, BF% = 14.2 ± 2, LBM = 65.3 ± 8 kg, age = 22.7 ± 4 years, height = 177 ± 7 cm, weight = 76 ± 9 kg, V̇O2max = 60.1 ± 4.5]; [LBF% < 11.5%, n = 9; BF% = 8.1 ± 1, LBM = 65.9 ± 5 kg, age = 20.1 ± 3 years, height = 179 ± 4 cm, weight = 72 ± 5 kg, V̇O2max = 61.6 ± 4). Players underwent a simulated soccer game protocol on a treadmill. Cardiometabolic and hormonal responses, and fuel oxidation and performance, were evaluated. At baseline, apart from the BF% variable (p < 0.0001), the groups did not differ in any other physiological or physical characteristic (p > 0.05). There were no differences between the groups in any performance or biological parameters evaluated (p > 0.05), except for plasma glucose, which was higher in the HBF% group at rest and during the soccer game protocol (p < 0.05). In conclusion, the theory of a uniform ideal (~10 ± 2%) of BF% in elite soccer is not supported by the present study. This study suggests that when muscle mass and fitness levels of the soccer players are maintained at high levels during the competitive period, BF% represents a highly individualized characteristic rather than a uniform target across players. However, a higher BF% increased resting and exercising blood glucose concentrations, even in highly trained professional soccer players, without concomitant effects on metabolism or fuel oxidation during match play.

20 A Call for Consensus: A Narrative Review of GPS-Based External Training Load Monitoring in Male Youth Soccer Players

Reference: Sports (Basel). 2026 Apr 14;14(4):152. doi: 10.3390/sports14040152.
Authors: Krisztián Havanecz, János Matlák, Ferenc Ihász, Gábor Géczi, Bence Kopper, Sándor Sáfár, Gábor Schuth
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13119910/pdf/sports-14-00152.pdf
Summary: Global positioning system (GPS) technology is widely used to quantify external training load (ETL) in youth soccer. Despite its extensive application in training and match contexts, considerable heterogeneity is present in the selection, definition, and interpretation of GPS-derived variables, limiting comparability between studies and practical implementation by coaches. This narrative review aimed to summarize and critically evaluate the current literature on GPS-based ETL monitoring in youth soccer players, with a focus on commonly used variables, methodological considerations, and practical applications in training and match contexts. A narrative literature search was conducted using PubMed, SPORTDiscus, and Scopus databases. Peer-reviewed studies published in English between the years of 2012 and 2025 were included. Data were extracted on participant characteristics, GPS technology, monitored ETL variables, and contextual settings. The 34 reviewed studies primarily reported total distance (TD; m), high-speed running distance (HSR; m), sprint distance (SD; m), distance per minute (m·min-1), peak speed (km·h-1), and acceleration- and deceleration-based (ACC, DEC; count) ETL variables. Substantial variability was observed in speed thresholds, acceleration definitions, and data processing methods. Positional roles, training formats (e.g., small-sided games), and seasonal phase influenced ETL demands, although methodological inconsistencies limited cross-study comparisons. GPS technology provides valuable insights into the ETL demands of youth soccer. The lack of standardized variable definitions and thresholds remains a major limitation. Greater methodological consistency and clearer reporting standards are required to enhance the practical usefulness of GPS monitoring for coaches in youth soccer.

21 Assessing Strength Asymmetries with Rotational Inertial Technology: Exercise-Specific Patterns and Temporal Changes in Professional Male Soccer Players

Reference: Sports (Basel). 2026 Apr 9;14(4):145. doi: 10.3390/sports14040145.
Authors: Alvaro Murillo-Ortiz, Javier Raya-Gonzalez, Moises Falces-Prieto et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13120088/pdf/sports-14-00145.pdf
Summary: Inter-limb asymmetries are common in soccer players and are frequently monitored in high-performance settings; however, their expression across different flywheel-based strength exercises, movement phases, and over time remains unclear. This study aimed to (i) compare inter-limb power asymmetry magnitudes across multiple unilateral flywheel exercises and between concentric (CON) and eccentric (ECC) phases, and (ii) describe changes in these asymmetries over an 8-week period of routine soccer training, stratified by baseline asymmetry magnitude. The present study was designed as an observational and descriptive study. Twenty-one professional male soccer players completed two testing sessions separated by eight weeks. Players performed six unilateral flywheel exercises targeting hip- and knee-dominant quadriceps (Qhip, Qknee), hip- and knee-dominant hamstrings (Hhip, Hknee), adductors (ADD), and abductors (ABD). For each exercise and limb, the repetition with the highest CON mean power and its consecutive ECC phase were selected for analysis. Inter-limb asymmetry (%) was calculated for mean and peak power in both phases. Across exercises, ECC asymmetries were generally greater than CON asymmetries, with the largest values observed for Qknee peak power (CON: 12.86 ± 11.04%; ECC: 27.60 ± 13.65%) and Hknee peak power (CON: 10.45 ± 11.26%; ECC: 24.01 ± 20.46%). Exercise-specific patterns were evident, with generally weak associations between asymmetries across tasks. Over time, players classified with higher baseline asymmetry (≥10%) presented lower values at follow-up in several outcomes (particularly ECC-related measures), whereas players with lower baseline asymmetry (<10%) showed small increases or remained stable; These between-group patterns should be interpreted cautiously, as they may be more strongly influenced by regression to the mean and measurement variability than by underlying physiological changes. Overall, inter-limb power asymmetries assessed with flywheel technology were phase- and exercise-specific in this professional soccer sample. These descriptive findings may help contextualize phase-specific and multi-exercise asymmetry monitoring in professional soccer settings.