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 Effects of Bilateral Soccer Training on Reactive Agility, Decision-Related Performance, and Lower-Limb Laterality Across Field Positions in Young Soccer Players

Reference: Percept Mot Skills. 2025 Dec 26:315125251409475. doi: 10.1177/00315125251409475. Online ahead of print.
Authors: Ahmed Ben Kahla, Yousri Elghoul, Fatma Bahri, Inês Srioui, Liwa Masmoudi, Riadh Dahmen
Summary: The laterality of the lower limbs, reactive agility, and decision-related performance are key determinants of performance in young soccer players. This study investigated the effects of a bilateral soccer training program -incorporating both the preferred (PL) and non-preferred leg (NPL) -on reactive agility and decision-related performance across playing position in youth players. A total of 118 right-foot-dominant young soccer players were randomly assigned to either an experimental group (EXP), which underwent bilateral training, or a control group (CONT), which continued their usual training routine. Each group was further subdivided according to primary playing positions: side backs (SB), central backs (CB), central defending midfielders (CDM), central attacking midfielders (CAM), and forwards (FW). We assessed the players‘ lateral asymmetries before and after training using the Y-Agility test, the Agility and Skill test, and the Juggling coordination test. The results demonstrates significant improvements on the Agility and Skill Test across all playing positions in the EXP group and only among CBs in the CONT group (p < .05). Furthermore, within the EXP group, CDMs, CAMs and FWs showed significantly greater improvements than CBs and SBs (p < .05). These findings highlight the benefits of bilateral training in improving reactive agility, technical skills, and decision-related performance in young soccer players, and suggest that effects may vary according to playing position, though positional fluidity at the U15 level warrants cautious interpretation.

2 High-magnitude headers are not associated with structural and functional brain changes in active high-level football (soccer) players

Reference: BMJ Open Sport Exerc Med. 2025 Dec 23;11(4):e002636. doi: 10.1136/bmjsem-2025-002636. eCollection 2025.
Authors: Franziska Katharina Mund, Nina Feddermann-Demont, Goetz H Welsch, Carsten Schuenemann, Jens Fiehler, Christian Thaler, Lukas Meyer, Rebecca Reeschke, Claus Reinsberger
Download link: https://bmjopensem.bmj.com/content/bmjosem/11/4/e002636.full.pdf
Summars: To date, consistent evidence for consequences of heading in football (soccer) on the structure and function of the brain is lacking, but first studies indicate a potential effect of specific high-magnitude headers. The purpose of this longitudinal, prospective study was to investigate whether potential structural and/or functional alterations within the brain were associated with (high-magnitude) heading. 3T MRI sequences were obtained from active high-level male players before and after an observation period of 17.2 months (median). Cortical thickness and grey matter (GM) volume were investigated on a whole-brain level. Functional connectivity (FC) was analysed in the default mode network (DMN) and salience network (SN). During the observation period, each training and each match was videotaped and evaluated regarding the heading exposure. Significant structural and functional findings were subsequently correlated with specific header characteristics. 14 included participants (mean age: 20.36±3.34 years) played 5822 headers. GM volume remained unchanged, whereas cortical thickness decreased minimally from pre-measurement to post-measurement in a left precentral region (mean change: 0.048±0.128 mm; clusterwise p=0.0416). Within the SN, FC increased in one cluster (false discovery rate corrected p=0.026). FC remained stable within the DMN and between DMN and SN. Change from pre-measurement to post-measurement for the significant results did not correlate with heading variables. Our findings may indicate no cumulative effect of heading during the observation period. As these results contrast with cross-sectional findings, more longitudinal, prospective studies with a greater sample size are urgently needed to understand potential heading effects.

3 Competition Stress Prolongs Exercise Recovery in Female Division I Collegiate Soccer Players

Reference: Sports (Basel). 2025 Dec 16;13(12):454. doi: 10.3390/sports13120454.
Authors: Courtney D Jensen, Ryann L Martinez, Nathaniel J Holmgren, Alexis C King
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736549/pdf/sports-13-00454.pdf
Summary: This study examined the effect of competition stress on recovery time in female collegiate soccer players. Thirty NCAA Division I athletes were monitored over 35 consecutive days using Polar Team Pro wearable devices, which captured exercise duration, distance covered, energy expenditure, sprint count, speed, heart rate, training load, and recovery duration. Data were collected across 20 practices and 7 competitions, totaling 845 observations. Linear regression was used to assess whether formal competition independently influenced recovery duration, controlling for time of day and workload variables. Athletes averaged 20.1 ± 1.1 years of age. Across all sessions, the mean exercise duration was 59.5 ± 38.7 min, with an average distance of 2.6 ± 2.1 km, and energy expenditure of 387.2 ± 283.5 kcals. Recovery duration was significantly longer after competition (51.3 ± 59.6 h) compared to practice (13.0 ± 15.8 h, p < 0.001). The regression model indicated that formal competition predicted an additional 51 h of recovery time (β = 50.540; p < 0.001), independent of physical workload. Recovery following formal competition is significantly prolonged, holding multiple components of workload constant. These findings offer novel insights into female athlete recovery and highlight the importance of sex-specific approaches in sports science.

4 Effect of Linear Sprints and Change-of-Direction Training Versus Small-Sided Soccer Games on Physical Performance in Highly Trained Young Female Soccer Players: A Randomized Cross-Over Study

Reference: Sports (Basel). 2025 Dec 10;13(12):445. doi: 10.3390/sports13120445.
Authors: Abdelwahid Aboulfaraj, Fatiha Laziri, Salah Eddine Haddou, Salah Lahlou, Mohamed Aghrouch, Ali Belamjahad, Juan Del Coso, Luca Paolo Ardigò, Hassane Zouhal
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736834/pdf/sports-13-00445.pdf
Summary: This study aimed to compare the effects of linear sprint training with changes of direction (LSCD) versus small-sided games (SSSG) on physical performance, agility, and soccer-specific skills in young elite female players. In a randomized crossover study, 27 players aged 15 to 17 were divided into two groups (G1 = 14, G2 = 13). After a two-week baseline period, each group completed a four-week training mesocycle (three sessions per week) consisting of either LSCD or SSG. After a two-week washout period, participants switched interventions and completed the alternate four-week mesocycle. Performance assessments were conducted before and after each mesocycle to evaluate training effects. Both types of training improved physical performance, with different magnitudes. LSCD induced larger gains in sprint speed (5, 10, 20 m; p < 0.05), agility without the ball (t-test; p = 0.05), and explosive power (countermovement jump, repeated jumps over 15 s; p = 0.02 and p = 0.004). In contrast, SSSG led to larger improvements in aerobic endurance (Yo-Yo IR1 test; p = 0.03) and agility with the ball (t-test with ball; p = 0.05). No transfer effect between cycles was observed. In young elite female players, LSCD training was more effective in improving speed, agility, and power, while SSSG was more effective for aerobic endurance and ball agility.

5 Skin Temperature as a Marker of Physical Fitness Profile: The Impact of High-Speed Running in Professional Soccer Players

Reference: Sports (Basel). 2025 Dec 9;13(12):443. doi: 10.3390/sports13120443.
Authors: Victor-Luis Escamilla-Galindo, Armiche Vega-Ramos, Jose Luis Felipe, Antonio Alonso-Callejo, Ismael Fernandez-Cuevas
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12737219/pdf/sports-13-00443.pdf
Summary: High-speed running (HSR) has the greatest physiological impact on soccer players. It is closely linked to neuromuscular fatigue and muscle damage post-match, emphasizing the role that load monitoring plays in both performance and recovery. The aim of this study was to examine the relationship between match locomotor demands and the relative change in skin temperature (%ΔT) following official matches. A professional soccer team was analyzed during 14 regular-season matches. Infrared thermography (IRT) assessments were conducted before the match and up to 36 h after the match. The analyzed regions included posterior protocols of the lower limb. The kinematic variables of the match were obtained through a GPS device. Players were classified into high- and low-load groups based on the median values of HSR distance (372 m) and total distance (9675 m). Linear mixed-effects models showed that players in the high HSR group (≥372 m) demonstrated greater post-match decreases in %ΔT, particularly in the hamstring region (β = -1.79 ± 0.54 °C, 95% CI: -2.87 to -0.72, p = 0.001, R2 = 0.18), with a moderate-to-large effect size (ES = 0.67). Total distance also explained temperature change in the hamstrings (β = -1.46 ± 0.73 °C, p = 0.04). These findings suggest that post-match skin temperature reduction is sensitive to high-intensity running exposure, supporting IRT as a complementary internal load monitoring tool.

6 Exercise Heart Rate During Training and Competitive Matches in Elite Soccer: More Questions than Answers

Reference: Sports (Basel). 2025 Dec 8;13(12):441. doi: 10.3390/sports13120441.
Authors: Iwen Diouron, Cédric Leduc, Guilhem Escudier, Stéphane Perrey
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12737241/pdf/sports-13-00441.pdf
Summary: Monitoring the training load of elite soccer players is a common practice for clubs. However, limited information exists about the internal load experienced by elite soccer players. The heart rate (HR) exposure of 51 French elite soccer players was monitored using conductive vests incorporating ECG bands during two consecutive seasons using a three-zone intensity model. HR exposure was broken down into volume (i.e., total time in the three zones) and intensity (i.e., relative time in the three zones). The effect of playing position, as well as the period (monthly or daily), was assessed. Regarding seasonal exposure, a significant difference was observed between key periods of the season (i.e., preseason, in season, end-of-season) for both volume and intensity (p < 0.05). Noteworthily, monthly HR exposure was relatively constant across competitive period. For weekly exposure, a significant difference in HR volume and intensity was observed between matches and training sessions (p < 0.001) potentially highlighting gaps in players‘ readiness. Note that there were small variations in terms of HR exposure between the three first training days (p < 0.05), especially for time and relative time over 90% of maximal HR (not significant). This study not only provides insight into typical HR exposure in elite football but also questions the current training periodisation.

7 Youth Soccer Development After a Forced Training Interruption: A Retrospective Analysis of Prepubertal Players

Reference: Sports (Basel). 2025 Dec 4;13(12):435. doi: 10.3390/sports13120435.
Authors: Federico Abate Daga, Italo Sannicandro, Alice Tanturli, Samuel Agostino
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736573/pdf/sports-13-00435.pdf
Summary: This retrospective, non-interventional study investigated the impact of a forced training interruption, such as the COVID-19 nationwide lockdown, on the physical efficiency, performance, and technical-agility skills of prepubertal soccer players by comparing pre- and post-interruption cohorts within the same youth academy and at the same chronological age. Anonymised data collected across multiple competitive seasons included anthropometric measures and motor performance tests: Standing Long Jump, Shuttle Run, Shuttle Dribble, and Mini Cooper. Between-group differences were analysed using Mann–Whitney U tests, with p < 0.05 as the level of significance. The post-training interruption cohort showed significantly higher values in the Standing Long Jump (+11.2%, p < 0.001) and the Shuttle Run (+8.0%, p = 0.011), indicating improved explosive power and agility-speed. Conversely, performance on the Shuttle Dribble test declined by 13.4% (p < 0.001), while Mini Cooper results and BMI did not differ significantly. These findings suggest that modifications to compulsory training and children’s natural adaptability may have enhanced physical abilities, whereas the lack of contextual and interactive practice negatively affected technical-agility skills. Coaches should incorporate alternative workouts to maintain motor performance and emphasise ball-related and decision-making drills within ecological and dynamic environments to maximise developmental outcomes. This study offers new insights into the adaptive responses of young athletes and provides practical lessons for future youth soccer development, particularly during periods of forced training interruption.

8 Measured vs. Estimated V˙O2max in the Yo-Yo Endurance Test: An Exploratory Study in Professional Soccer Players

Reference: Sports (Basel). 2025 Dec 2;13(12):424. doi: 10.3390/sports13120424.
Authors: Antonio Buglione, Dario Pompa, Marco Beato, Marco Bruno Luigi Rocchi, Cristian Savoia, Maurizio Bertollo, Davide Curzi, Davide Sisti, Fabrizio Perroni
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736578/pdf/sports-13-00424.pdf
Summary: Accurate assessment of aerobic fitness is crucial in soccer; however, the validity of field-based predictive tests remains uncertain in professional players. This study examined the relationship between directly measured and estimated maximal oxygen uptake (V˙O2max) during the Yo-Yo Endurance Test Level 1 (YYET1) in professional soccer players and evaluated seasonal changes after six months of training and competition. Seventeen players from an Italian third-division team performed the YYET1 in pre- and mid-season conditions, while VO2max was continuously recorded using a portable metabolic system. VO2max was estimated using Bangsbo’s distance-based formula. Linear regression and Bland-Altman analyses were used to assess relationships and agreement between methods. Measured VO2max increased significantly from pre- to mid- season (+13.9%, p < 0.001), whereas estimated values showed a smaller rise (+5.2%, p < 0.001). The predictive method systematically underestimated VO2max (bias -2.3 to -7.0 mL·kg-1·min-1), and regression analyses revealed only moderate shared variance (R2 = 0.18-0.20) between estimated and measured values. These findings demonstrate that Bangsbo’s equation lacks validity for estimating VO2max in professional players and cannot accurately track aerobic adaptations across a season. For precise physiological evaluation, direct measurement using portable metabolic systems is required, while submaximal soccer-specific protocols may offer practical alternatives for longitudinal monitoring.

9 Can Recreational Soccer Improve Physical Literacy Dimensions Among Adolescents with High Cardiometabolic Risk?

Reference: Sports (Basel). 2025 Dec 2;13(12):423. doi: 10.3390/sports13120423.
Authors: Gustavo Pavez-Adasme, Juan Párraga-Montilla, Cristián Martínez-Salazar, Marcelo Castillo-Retamal, Pedro Latorre-Román, Nicolás Gómez-Álvarez
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12737039/pdf/sports-13-00423.pdf
Summary: This study aimed to analyze whether recreational soccer, through small-sided and traditional soccer formats, can promote improvements in different dimensions of physical literacy among adolescents with high cardiometabolic risk. A randomized controlled trial was conducted with two experimental conditions (small-sided soccer games and traditional soccer) and one control condition. A total of 51 male adolescents aged 11-15 years with high cardiometabolic risk participated in the study. A model including three dimensions of physical literacy was established: physical, psychological, and cognitive dimensions. Data were standardized using z-scores to allow variable weighting within the model, and effect sizes and ANCOVA were used for inter- and intragroup comparisons. The overall effect on physical literacy was small (ES: 0.31). The small-sided soccer group showed better results in the physical and psychological dimensions. The per-protocol analysis showed small effects in the high-adherence groups (ES = 0.43 and 0.38) and significant within-group differences; however, the post hoc analyses only revealed trends when compared with the low-adherence groups. Recreational soccer, whether in SSG or TSG formats, was insufficient to elicit significant improvements in physical literacy among adolescents with high cardiometabolic risk. Participants with higher adherence showed better outcomes, with SSG showing a clear tendency toward greater improvements in the physical and psychological domains.

10 Effect of a Visual Dual-Task on Single-Leg Countermovement-Jump in Male Professional Soccer Players with Lower-Limb Injuries: A Cross-Sectional Observational Study

Reference: Sports (Basel). 2025 Dec 1;13(12):419. doi: 10.3390/sports13120419.
Authors: Geoffrey Memain, Christopher Carling, Jean Bouvet, Paul Fourcade, Pascal Maille, Eric Yiou
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736822/pdf/sports-13-00419.pdf
Summary: Participation in soccer imposes high physical, mechanical, and cognitive demands. Recent evidence suggests that cognitive load, often overlooked in injury prevention, interacts with biomechanical factors and injury risk, resembling a dual-task paradigm where players must adapt motor responses while processing unpredictable game situations. This cross-sectional observational study examined how adding a dual-task during single-leg countermovement-jumps (SLCMJ) affects neuromotor control and performance in elite soccer players. Players performed SLCMJ on the injured leg while muscle activation, kinematics, and kinetics were measured, with and without a dual-task requiring color identification, via repeated-measures ANOVA; three injured groups (Chondropathy, n = 10, ACL, n = 15, Muscle Injury, n = 15) and a healthy control group (n = 22, followed the same protocol during final-rehabilitation stage. Specific main outcomes were kinetics, kinematics, and EMG variables. Kinetic performances were significantly higher (p < 0.001, d > 0.6) with dual-task: eccentric rate-of-force-development, jump-height, reactive-strength-index-modified, and shorter for time-to-peak of ground-reaction-force (p < 0.05, d > 0.6). Muscle activation increased with dual-task in rectus femoris and biceps femoris during pushing (eccentric and concentric phases) (p < 0.01, d = 0.7) and for medial gastrocnemius during landing (p < 0.05, d = 0.7). Kinematic analyses showed greater pushing knee flexion, while pushing and landing trunk flexion was lower (p < 0.01, d > 0.8). Kinetic values in the three injured groups were lower than those of controls (p < 0.01, d > 0.8). Injured elite soccer players appeared disinhibited in dual-task conditions that improved SLCMJ performance but altered neuromotor control, underscoring the importance of a neurocognitive approach in return-to-play assessments to evaluate reinjury risk.

11 The Impact of Oral Health on the Number of Missing Matches and Physical Performance in Elite Male Soccer Players

Reference: Sports (Basel). 2025 Dec 1;13(12):417. doi: 10.3390/sports13120417.
Authors: René Schwesig, Stephan Schulze, Lars Reinhardt, Eduard Kurz, Andreas Wienke, Thomas Bartels, John Brandes, Christian Ralf Gernhardt
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736717/pdf/sports-13-00417.pdf
Summary: Oral health (OH) seems to be relevant for the number of sick and injured days (NSID), missing matches (MM) and secondarily for the physical performance (PP). The objective was to clarify possible associations between OH, NSID, and PP for elite soccer players. Thirty-nine male athletes (age: 24.6 ± 4.2 years, age range: 17-34 years) from a third league professional soccer team were examined concerning several dental parameters (decayed, missing, and filled teeth, DMFT; periodontal screening index, PSI; approximal plaque index, API; papillary bleeding index, PBI) and PP parameters. The PP diagnostic contains grip strength, posturography, jump and sprint tests, and an endurance test on treadmill. Furthermore, the number of sick and injured days and missing matches was collected and assessed over four seasons. We could not find any relevant (r > 0.7) correlations between sick and injured days or missing matches and variables of different dimensions (OH, PP). The soccer players showed a remarkable level of oral health (missing teeth, MT: 0.18 ± 0.56), jumping performance (44.5 ± 5.42 cm), and grip strength (53.7 ± 7.02 kg). The endurance capacity (velocity at 4 mmol/L lactate threshold, v4: 14.9 ± 1.11 km/h) was on an average level, whereas the levels of postural stability (stability indicator, ST: 20.0 ± 4.55) and sprinting performance (10 m sprint: 1.79 ± 0.09 s) were comparatively low. Only five players (13%) reported that oral health had ever had a negative impact on his physical performance. Two players (5%) reported currently tooth pain and six players (15%) bleeding gums or grinding teeth. Based on the high level of dental health, it was difficult to prove any relationships between OH and the NSID/MM or PP. Nevertheless, it seems that young soccer players benefit particularly from improved oral health programs. The excellent dental care appears to have a positive effect on general health and physical performance in soccer.

12 Associations between executive functions, coaches‘ evaluation, and performance development in youth soccer

Reference: Sci Rep. 2025 Dec 22;15(1):44335. doi: 10.1038/s41598-025-33159-4.
Authors: S Knöbel, M L Reinhard, A Borchert, N Gatzmaga, L Musculus, F Lautenbach
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12727806/pdf/41598_2025_Article_33159.pdf
Summary: Understanding the role of executive functions (EFs) in sports performance is a central focus for practitioners and researchers in sports psychology, particularly in soccer. Prior studies suggest links between EFs and elite performance or game-specific skills, increasing their consideration in talent identification and development. Yet, the validity and predictive value of EF measures remain uncertain. This study examines the relationship between inhibition, cognitive flexibility and soccer performance development in a sample of youth elite players (Mage = 15.17, SDage = 1.3). Specifically, we investigate (i) associations with coaches‘ evaluations of future potential (n = 74), (ii) age-related development (n = 34), and (iii) the predictive value of EFs for senior performance levels (n = 69). Multinomial logistic regression analyses revealed no significant evidence that EFs explain elite soccer performance (for (i) all p ≥ .125; for (iii): all p ≥ .058). Multilevel analyses showed cognitive flexibility following age-related developmental trends similar to the general population (ii). These findings question whether a robust link between EFs and performance ratings exists. Given the small sample size, this study emphasizes the need for further, more nuanced research on the predictive value of EFs in the context of talent identification and development.

13 Simulated soccer pressing scenarios alter kinematics and kinetics of sidestep cutting associated with ACL injury risk

Reference: Sports Biomech. 2025 Dec 22:1-20. doi: 10.1080/14763141.2025.2594630. Online ahead of print.
Authors: Tatsuya Kono, Yoshitsugu Tanino, Noriyuki Kida
Summary: In soccer, anterior cruciate ligament (ACL) injuries frequently occur during sidestep cutting (SSC) in pressing situations. This study examined the effects of soccer-specific pressing tasks on SSC kinematics and kinetics. Twenty male recreational soccer players performed a 90° SSC followed by three task conditions: the Normal condition, in which participants simply continued running; the Pressing 70% condition, in which they reached for a ball placed at 70% of maximal straddle width; and the Pressing 100% condition, in which they reached for a ball at 100%. Maximal straddle width was defined as the distance between the toes during maximally hip-abducted. Both pressing conditions simulated defensive pressing. Three-dimensional peak knee and trunk angles, ground reaction forces, and knee moments of the supporting leg during the first 50 ms of the stance phase were compared. Results showed that peak knee valgus and trunk lateral inclination angles, as well as peak knee flexion, valgus, and internal rotation moments, were greater in both pressing conditions. These findings indicate that simulating pressing tasks altered SSC kinematic and kinetic characteristics. Notably, variables associated with ACL injury risk increased under pressing tasks, suggesting that pressing situations themselves may represent a biomechanical ACL injury risk.

14 Neurological mechanisms of mental fatigue in cognitive flexibility in soccer players: an event-related potential study based on N2 components

Reference: Front Neurosci. 2025 Dec 5:19:1729495. doi: 10.3389/fnins.2025.1729495. eCollection 2025.
Authors: Chen Gong, Jun Zhao, Yifan Wang, Xuejian Ding
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12714972/pdf/fnins-19-1729495.pdf
Summary: Mental fatigue frequently occurs in team sports characterised by high cognitive demands and can adversely affect athletes‘ decision-making and executive functions. This study examines the impact of mental fatigue on cognitive flexibility in soccer players, employing event-related potentials (ERP) to elucidate the underlying neural mechanisms. Eighteen football players from the China University Football Association (CUFA) participated in the study. The research utilised the Stroop task to induce mental fatigue and the More-odd switching task to evaluate cognitive flexibility, with measurement indicators comprising accuracy rate (ACC), reaction time (RT), and N2 component amplitude. The experimental design adhered to a repeated measures protocol, incorporating 2 (time: pre-fatigue/post-fatigue) × 2 (task type: conversion/non-conversion) × 4 (electrode positions: Fz, Cz, Pz, F3) factors. Statistical analyses of behavioural data were conducted using non-parametric tests, while ERP data were examined through repeated measures ANOVA. Mental fatigue significantly impaired athletes‘ accuracy in the More-odd switching task, evidenced by decreased performance in both conversion and non-conversion conditions (p < 0.05), alongside prolonged reaction times (p < 0.01). Event-related potential (ERP) analysis demonstrated a marked reduction in the amplitudes of the N2 component post-intervention, with notable differences across electrode sites (F = 3.192, p = 0.031). These findings suggest a restriction in cognitive control resources within the frontal and parietal regions. This study illustrates that experimentally induced mental fatigue has a significant detrimental impact on the cognitive performance of football players, leading to slower reaction times and decreased neural electrophysiological indicators (specifically, a reduction in N2 wave amplitude), indicating a decline in conflict monitoring ability. An integrated examination of both behavioural and neurophysiological data indicates that the adverse effects of mental fatigue are likely due to the depletion of general cognitive control resources that rely on the prefrontal cortex, rather than targeting particular cognitive functions. These results offer initial insights into the cognitive and neurological alterations in fatigued athletes. While the study did not explore interventions, the findings lay the groundwork for the development of tailored cognitive training programmes and fatigue management strategies, along with potential evaluation criteria. Notably, the N2 wave amplitude serves as a key metric for assessing cognitive resource levels in football players.

15 Acute hematological, metabolic, and inflammatory responses to simulated-6000 ft masked versus unmasked high-intensity interval training in youth soccer players: a randomized crossover pilot study

Reference: BMC Sports Sci Med Rehabil. 2025 Dec 22. doi: 10.1186/s13102-025-01426-6. Online ahead of print.
Authors: Tevfik Akol, Ayşegül Yapici, Gülin Findikoğlu Ergin, Engin Güneş Atabaş
Download link: https://link.springer.com/content/pdf/10.1186/s13102-025-01426-6_reference.pdf

16 Biomechanical effects of different change of direction angles on lower limb joint load and injury risk in soccer players

Reference: Sci Rep. 2025 Dec 22. doi: 10.1038/s41598-025-33102-7. Online ahead of print.
Authors: Jianjun Li, Haonan Qian
Download link: https://www.nature.com/articles/s41598-025-33102-7_reference.pdf

17 Mitigating climate change in sports leagues: A scenario-based analysis of travel distances in women’s and men’s amateur soccer in Germany

Reference: J Sport Health Sci. 2025 Dec 19:101112. doi: 10.1016/j.jshs.2025.101112. Online ahead of print.
Authors: Karim Abu-Omar, Tobias Völk, Antonina Tcymbal, Julian Resch, Dogukan Özer, Peter Gelius, Sven Messing, Heiko Ziemainz
Download link: https://pdf.sciencedirectassets.com/282623/AIP/1-s2.0-S2095254625001206/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjELn%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJIMEYCIQDaPz6FRJbQdgnWbx0dE67G2W7W0k177GPEc0ta2Xd2uwIhAIEbOQKwbxdnDk%2Bkw7D8WNERDdGM5fjDeYkDtackr7xuKrsFCIL%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEQBRoMMDU5MDAzNTQ2ODY1Igwn%2BLFvF6A6K90uSdYqjwXu6pjTlWVEj2SEJRLgAgq9y33BAtN12wa%2Bxq9799qRiLGt3ZgHtS1fhl41ZqdID00JrIl717qr31zMErvWlGozQOdEbzl0kv4e0Tb8BgX3WZphqWMqtA68xezTKs%2FYNsfsb0WMv3qj%2FcALNmXpMMNy1lWDkEH%2FmqSeuuUn0F7bQP%2FVBmJFQRgGO9gT1C5dmn1ZCeRfob%2BPRc8tkFQUrxYzOa4QWodXGKvaEGe%2Bv6pZtTtY6FrMNe0laSz4I6MsJaI2mq5P0yqVkI8H%2FEuq5KtGnAL8d6Yasf4oHqhslFZd0HkjkeMqM4apTYTqDI6SMUql8XNNz%2BCoUP%2FzPcO7HF5urzSa6A%2F2J%2Bp5Z2RmP9pzYcEdP9kr1ytc4tJWvScXr%2BMyKO3c%2F7g8vWi%2FR39rr3H3thKAQygm9SWM%2Bms3KASXHR67ucTwvoKaIyMWfp8CtX9%2BF4IpZbGK%2FgCKv7k7YKHKKv301uUkAfcKviHwtD%2BomcpfafRJfrTfl24lWU105osVyhxXbajxC8sSrH32WuTCb40sorATYnSPUnOxfqCCF44Khww%2FK3gI28cH5ZdrZlVOhCdSj8JFnC3XoW7Vm8p3x70LBdwcg29sYjz88agLu%2FmdVAU%2Bw897kfwfdtbSI2E2R3Fd%2F%2FlE30e96RmhTHZyRxDlJ2%2BaKramWg3702vm3cYyVoGNzKtR4j4EzX1xgCnt5tnV3d%2F4RS9IVM2EOygzEqIWR11reJ0Y1n3MNUriRBTMFp6PBnQRF%2FHTEhM5O0%2Bi00xt3Bt15%2BYBjNhWPTbK%2FQNCUFO7d%2FjLpKX1a9%2FfyTW8VQbkqGdAWC1wgxCg5bXlJcXUJnQ4NkKbAxQxsC2IpmrsBqBMASQ3SrlG5%2BGnMKbcw8oGOrAB58fAQGXNDXP6w5NUvb37v2EIJxPl52BcgDdyqH6wyzeeg2xS%2FYZo%2BeEQ%2BhUtXp0fqWAysaMopPgLVjkvDS1VH9LS98nQkU62ggYHix%2F%2F9e2bV90fin4YTCfQKmUCvOK0v2zt7yTocgp1c0HT8mzhqnJ0iYgR%2B7BAhaOx9uksGl4KKuE76yLiMFBilgZdGFFcwFChBILBRXnhwFqP000cr%2BONIsbMF3Z1gx1FEPCuxl8%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20251228T090137Z&X-Amz-SignedHeaders=host&X-Amz-Expires=299&X-Amz-Credential=ASIAQ3PHCVTYZYQ7YOVP%2F20251228%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=1a76089dea9223cfe8b4169ab1cfce21ed588925bcc611904416d739e0aaad1f&hash=c1cb3910f3da818d07753bf0f74f8418db6799a797a3eb8d09e79cb1c43f7ed8&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S2095254625001206&tid=spdf-b15c171e-7d3d-420f-ab8b-2fa7cac3dbe2&sid=a6b1e6b67c9a424e425aba1489dd44cab1dcgxrqa&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&rh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=02015700560300070155&rr=9b4fdfc37d8f68e5&cc=de
Summary: Travel to away games is a major but under-studied source of greenhouse gas (GHG) emissions in grassroots sport. We quantified these emissions and tested scheduling solutions that could make amateur soccer „climate-smart“. Match schedules for the 2022/23 season of 384 amateur women’s and men’s teams (35 groups from the 6 lowest leagues) in 3 German regions were geocoded. Baseline round-trip driving distances were calculated then converted to GHG equivalents (217 kg/100 km). Two optimization scenarios were modeled: (A) reallocating teams to geographically compact groups; (B) placing all teams in 1 league with an unbalanced schedule favoring nearby opponents. To generate near-optimal solutions, we used mixed-integer programming and custom heuristics. Current scheduling required 156,558 km of travel (106.5 to 159.7 tons of GHG). Scenario A cut distance to 117,428 km (-25 %), Scenario B to 101,333 km (-35 %). League-level savings ranged from 2% to 57% (A) and 21% to 62% (B); the urban men’s league achieved the largest absolute reduction (-20,853 km, -62 %). In total, switching to Scenario B would save 37.5 to 56.4 tons of GHG compared to the current scheduling without reducing the number of matches. Simple, data-driven changes to group composition or match scheduling can substantially shrink the carbon footprint of grassroots soccer while maintaining competitive integrity. Sports federations can adopt such optimization tools to align league operations with planetary-health goals.

18 Performance and injury-related effects of low-load blood flow restriction training in amateur soccer players: a randomized controlled trial

Reference: BMC Sports Sci Med Rehabil. 2025 Dec 20. doi: 10.1186/s13102-025-01416-8. Online ahead of print.
Authors: Begüm Kara Kaya, Ayşe Zengin Alpözgen, Mehmet Rahmi Alpözgen, Göksel Dikmen
Download link: https://link.springer.com/content/pdf/10.1186/s13102-025-01416-8_reference.pdf
Summary: Blood flow restriction (BFR) has gained interest in its application in exercise and potential benefits. This study aimed to investigate the effects of low-load, low-frequency BFR training compared with traditional high-intensity training on soccer-related performance outcomes and injury indicators in amateur athletes. Twenty licensed male soccer players competing in a university-level league were randomized to either a BFR group (n = 10, 22.3 ± 1.3 years) or a control group (n = 10, 22.1 ± 1.8 years) for 6 weeks of training. Pre- and post-intervention assessments included muscle strength-endurance (isokinetic dynamometer), power (vertical jump test), aerobic endurance (Yo-Yo level 1 test), speed-agility (T test, Y-shaped reactive agility test), dynamic balance (Y test), thigh circumference, fatigue (blood lactate, Borg scale), and sportive self-confidence. Perceived change (GROC) was assessed post-intervention. Injury data were tracked for six months following the intervention. BFR improved dominant limb flexor strength, endurance, aerobic capacity, speed, and dynamic balance (p < 0.05, Cohen’s d: 0.40-1.06). Both groups showed gains in power, agility, and self-confidence (p < 0.05, Cohen’s d: BFR = 0.51-1.35; Control = 0.40-1.01), whereas hypertrophy (p = 0.026, Pη2 = 0.24) and GROC scores (p = 0.022) were significantly higher in the BFR group than in the control group. No differences were observed in terms of fatigue. The standard error of the mean values for significant within-group changes ranged from 0.03 to 8.64. Although the injury rate was lower in the BFR group, this trend was not significant (p > 0.05). BFR appears to be a feasible, load-efficient, and well-tolerated approach to improve performance parameters in amateur soccer players, with potential benefits for lower-limb injury prevention.

19 Associations of carbohydrate intake, high-speed running, and testosterone levels with body fat percentage in professional female football players: a longitudinal study

Reference: Br J Nutr. 2025 Dec 26:1-21. doi: 10.1017/S0007114525106041. Online ahead of print.
Authors: Nerea Peña, Javier Amézaga, Virginia Santesteban, Ana Belén Martinez, María Bulla, Isaac Subirana, Itziar Tueros
Summary: Body composition (BC) offers essential insights into the physical condition and performance capacity of athletes. Several factors can influence athletes‘ BC, such as nutrition, which can improve lean mass (LM) and body fat percentage (%BF). This longitudinal observational study aimed to investigate the factors influencing BC in professional female football players, including hormones, dietary habits, and physical activity, as these are relevant to their sport performance and health. Data related to dietary habits, DXA measurements, serum hormones, menstruation, and GPS metrics were collected in November 2023 and late March 2024 from 38 female football players from the Real Sociedad team. Of the 38 players enrolled, 35 completed all assessments and were included in the final analyses. Spearman correlations and linear regression analyses were performed. Statistically significant models were executed for %BF and LM (adjusted R2 = 0.55 and 0.47 respectively). For %BF, total testosterone had a positive influence while HSR (high-speed running) per minute, FSH, distance covered per minute, prolactin, and fat intake, influenced negatively. In the LM model, positive associations were total testosterone, progesterone, age, ACTH, and carbohydrate intake, while insulin, distance covered per minute, and, SHBG had negative associations. These results emphasise the complexity of the factors influencing BC in female football players. Personalising and periodising carbohydrate intake and monitoring training loads are crucial to prevent adverse effects like higher %BF and muscle catabolism. Establishing healthy nutritional practices is essential for long-term health and performance.

20 Chronological versus skeletal age and its relationship with motivational profiles and psychological skills among male youth football players from South Africa

Reference: S Afr J Sports Med. 2025 Dec 15;37(1):v37i1a21882. doi: 10.17159/2078-516X/2025/v37i1a21882. eCollection 2025.
Authors: S R Dube, E H Wik, S P Cumming, E W Derman, H W Grobbelaar
Summary: Self-determined motivation (SDM) and sport psychological coping skills are important for developing footballers. This study examined relationships between chronological age (CA), skeletal age (SA), and psychological variables among South African youth players. Data were collected from 109 male players across three football academies (mean CA: 14.8±2.4 years, mean SA: 14.2±2.1 years). Participants completed the Sport Motivation Scale-II (SMS-II) and the Athletic Coping Skills Inventory-28 (ACSI-28). Amotivation, external, and introjected regulations differed significantly across CA groups, negatively affecting the Relative Autonomy Index (RAI). SDM, as reflected by the RAI, declined with CA, reaching its lowest point between 15 and 17 years. SA grouping revealed significant differences for amotivation and external regulation. Coachability differed across CA and SA groups. Amotivation, external regulation, and coachability showed positive correlations with CA, while amotivation and coachability showed positive correlations with SA. Concentration showed opposite correlations with CA and SA when controlling for the other variable. CA grouping appeared to reflect differences in SDM more effectively than SA. While some psychological and motivational variables aligned more closely with CA or SA, others did not, highlighting the complex and multifactorial nature of these developmental relationships. Given the low internal consistency of several subscales, these findings should be interpreted cautiously and viewed as exploratory. Future research should adopt longitudinal designs and utilise culturally appropriate, psychometrically robust tools better to understand the development of psychological skills in this population.

21 Effects of virtual reality-based cognitive and technical drills on scanning and passing performance in youth football players: a randomized controlled study

Reference: BMC Sports Sci Med Rehabil. 2025 Dec 24;17(1):371. doi: 10.1186/s13102-025-01425-7.
Authors: Kaan Erişik, Ali Onur Cerrah, Fahri Safa Cinarli
Download link: https://link.springer.com/content/pdf/10.1186/s13102-025-01425-7.pdf
Summary: Traditional training methods often fall short in replicating the perceptual load of match environments. Virtual reality (VR) has emerged as a promising modality to enhance cognitive-motor integration in football contexts. This study aimed to examine the effects of a 7-week virtual reality-based training program designed to improve both scanning behavior and passing performance in youth football players, in comparison with traditional training methods. A parallel-group randomized controlled trial was conducted with 22 male youth players from U16-U17 squads (mean age = 16.77 ± 0.42 years), who were assigned to either a VR group (n = 11) or a control group (n = 11). The VR group completed 3 weekly sessions using the SensiballVR™ platform for a duration of 7 weeks, in addition to their regular training. Scanning frequency (before ball reception, during control, and off-the-ball) and passing performance (by execution type, outcome, and pass style) were assessed via video analysis in small-sided games pre- and post-intervention. Between-group analysis revealed that the VR group achieved significantly greater improvements across all scanning domains compared to the control group, with mean-based percentage increases (calculated as the average of individual relative changes) ranging from + 198% to + 456%, rising from group mean values of 18 to 43 scans before ball reception, 20 to 43 during ball control, and 257 to 714 off the ball, versus – 12% to + 37% in controls (p < 0.01; ES = 0.58-0.83). Within-group analysis confirmed that scanning frequency increased significantly from pre- to post-test in the VR group (p = 0.003, ES = 0.89), whereas only off-the-ball scanning improved in the control group (p = 0.008, ES = 0.81). In passing performance, the VR group improved significantly in one-touch short-successful passes (+ 38%, p = 0.006, ES = 0.83), whereas the control group showed no meaningful change (+ 28%, p = 0.247, ES = 0.35). Although the VR group initially showed higher performance in control-pass short-successful passes (p = 0.038; ES = 0.44), this difference did not remain significant after false discovery rate correction (q = 0.199). Under the same condition, penetrative passes also improved significantly within the VR group (+ 108%, p = 0.029, ES = 0.66). No significant effects were observed for multi-touch passes (p > 0.05). Preliminary evidence suggests that immersive VR-based training can meaningfully enhance scanning behavior in youth football players, while potential benefits for passing outcomes remain exploratory. These findings highlight VR technology as a promising complementary tool in modern football development frameworks for improving perceptual-cognitive skills and decision-making.

22 Core temperature responses of male football players during matches in the heat – Associations with physiological and running demands

Reference: J Sci Med Sport. 2025 Dec 15:S1440-2440(25)00537-7. doi: 10.1016/j.jsams.2025.12.009. Online ahead of print.
Authors: Edgar Schwarz, Catarina B Oliveira, Monica Duarte Muñoz, Agustín Alanis, Marcela Alanis, Aldo Lara, Alfredo Freeze, Júlio A Costa, Leander Eckerle, Tim Meyer, Rob Duffield
Download link: https://www.jsams.org/action/showPdf?pii=S1440-2440%2825%2900537-7
Summary: This study describes core temperature (Tcore) responses during football matches in warm to hot conditions. It aims to identify which physiological, running, and perceptual factors are associated with reaching high Tcore values while controlling for environmental conditions and cooling. Forty highly trained male youth football players participated in at least two out of four matches held at temperatures between 26 and 42 °C. In three matches, heat mitigation strategies (passive rest and 17 °C drinks, or cold towels and 5 °C drinks) were applied pre-match, at half-time, and in additional breaks per half. Match running, heart rates, hydration markers, and perceptual responses were measured and checked for associations with peak Tcore values via linear mixed models accounting for environmental conditions and heat mitigation strategies. Peak Tcore was 39.2 ± 0.5 °C (range: 37.9-40.1 °C). Higher total distance (β = 0.39 [0.13, 0.64], p = 0.004) and distance at low-to-moderate speeds (β = 0.44 [0.18, 0.69], p = 0.001) were associated with higher peak Tcore, while walking distance was inversely associated (β = -0.42 [-0.69, -0.15], p = 0.003). High-speed and sprinting distances were not associated with peak Tcore. Higher heart rate (β = 0.37 [0.10, 0.64], p = 0.008), sweat loss (β = 0.38 [0.14, 0.62], p = 0.002) and body mass loss (β = 0.20 [0.00, 0.40], p = 0.047) were also associated with higher peak Tcore. Rating-of-fatigue (p = 0.74), perceived exertion (p = 0.78), and thermal sensation (p = 0.98) were not associated with peak Tcore. High Tcore peaks were observed in all conditions and were associated with higher heart rate, sweat loss, and match running. Covering more distance at low-to-moderate speed was associated with a higher heat strain, whereas walking more (instead of running) was associated with lower Tcore peaks.

23 Heading in football matches: descriptive analysis of heading events from 687 matches across age groups in English Academy and First Team men’s professional football

Reference: Br J Sports Med. 2025 Dec 23:bjsports-2025-110804. doi: 10.1136/bjsports-2025-110804. Online ahead of print.
Authors: Michael Brownlow, Dominic Charles Townsend, Ian Varley, Bradley Sprouse, Mike Hughes, Arron Ackerman, David Taylor, Gill Myburgh, Paddy Riley, Sameer Patel, Antonio Belli, Matthew Green
Download link: https://bjsm.bmj.com/content/bjsports/early/2025/12/23/bjsports-2025-110804.full.pdf
Summary: The aim was to describe the frequency, rates and contextual features of heading in matches across the English men’s elite football pathway. This prospective observational cohort study coded purposeful heading events in English Premier League First Team (senior), Category 1 and Category 2 Academy matches played between April 2021 and June 2024. Using video analysis and predefined heading and match descriptors, the study focused on heading frequency, rates, preceding events and unintended head impacts occurring during heading events. A total of 687 matches were included in the analysis, yielding 26 510 purposeful heading events across 49 703 match minutes. Heading rates/min increased by 13% per age group, from U9s to senior levels, rising from 0.167 to 0.875 headers/min. Central defenders exhibited the highest heading frequency, accounting for 34.2%-36.3% of all heading events. The most common preceding event leading to a header was a long pass. Unintended head impacts during heading events were infrequent (31 occasions, <1% of all purposeful heading events), with the highest incidence (1 per 971 match minutes) observed in senior players and the lowest incidence (1 per 1852 match minutes) observed in foundation (under 9s to under 11s) players. Six players were removed from play following medical assessment. This is the first published study to report heading rates across an entire elite, men’s football pathway. The findings support data-informed decisions regarding heading exposure in elite male footballers and provide valuable insights for those preparing players for the demands of the elite game at different age levels. Unintended head impacts during heading events occurred more frequently in senior players. Further research is needed to understand the variability in heading exposure throughout an individual player’s development pathway and any potential clinical ramifications.

24 The Relationship Between Neurocognitive Function and Concussion in Women Professional Football Players: A Cross-Sectional Study

Reference: Sports (Basel). 2025 Dec 11;13(12):448. doi: 10.3390/sports13120448.
Authors: Freja Fredrika Lähteenmäki, Steve den Hollander, Dina Christa Janse van Rensburg, Tuomas Brinck, Gino Kerkhoffs, Vincent Gouttebarge
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736892/pdf/sports-13-00448.pdf
Summary: The aim was to determine the neurocognitive functions of women professional football players and explore their potential connection to concussions. An observational cross-sectional study was conducted via electronic questionnaires. Neurocognitive function was assessed with the „CNS Vital Signs“ testing tool. In total, 68 participants performed the neurocognitive function testing. Compared with the reference population, players scored within the average range (≥90) for 11 of 12 neurocognitive domains. Motor speed was above average (SS = 111.7). Overall, no significant neurocognitive deficits were observed. Thirty-two participants (43%) reported one or more concussions, with defenders being most affected (50%). Among defenders, 64% (n = 16) have a history of one or multiple concussions. Players with a history of three concussions showed significant deficits in the simple attention domain. Professional women footballers did not show significant signs of neurocognitive function deficits. However, a history of three concussions was significantly associated with lower standard scores for the simple attention neurocognitive domain.

25 Barriers and Facilitators in the Junior-to-Senior Transition in Male Football-A Scoping Review

Reference: Sports (Basel). 2025 Dec 5;13(12):440. doi: 10.3390/sports13120440.
Authors: João Tomás, Duarte Araújo, Diogo Martinho, João Ribeiro, Honorato Sousa, Adam Field, Hugo Sarmento
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12736883/pdf/sports-13-00440.pdf
Summary: Despite many young players showing strong potential, only a small fraction succeeds in the critical transition from youth to elite senior football. This scoping review synthesizes research on the junior-to-senior transition in men’s football, identifying main topics related with barriers and facilitators in the transition. Searches were performed in four databases (PubMed, Scopus, SPORTDiscus, and Web of Science) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA, 2020) guidelines, using the following keywords: „football“ OR football AND talent OR „talent identification“ OR „talent development“ OR expert* OR gift* AND „junior-to-senior“ OR „transition career“ or „athlete career transition“ OR „transition phase“. Original articles in English focused on the junior-to-senior process in male footballers were included. From 5307 titles, 35 studies met eligibility criteria. The most examined themes were psychosocial factors, including social support, stressors, and resilience. The reviewed studies identified organizational structure and effective club communication as facilitators and emphasized the importance of physical attributes to meet senior-level demands. Overall, the junior-to-senior transition is multifaceted, shaped by psychosocial, organizational, and physical factors. Despite robust research, gaps remain; future longitudinal and interdisciplinary studies should inform evidence-based strategies for optimizing player development and retention.