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 Approximately two-thirds of adolescent male soccer players had increased lateral ankle laxity with functional ankle impairments

Reference: Knee Surg Sports Traumatol Arthrosc. 2025 Nov 15. doi: 10.1002/ksa.70184. Online ahead of print.
Authors: Takuji Yokoe, Tsubasa Kawaguchi, Aya Kubo, Naosuke Kamei, Atsushi Teramoto, Masato Takao, Hélder Pereira
Summary: The primary purpose of this study was to evaluate the prevalence of increased lateral ankle laxity (ILAL) in adolescent male soccer players. The secondary purpose was to investigate functional ankle impairments and muscle strengths related to chronic lateral ankle instability (CLAI). The anterior talofibular ligament (ATFL) lengths of adolescent male soccer players were measured in the stress and non-stress positions using ultrasonography. The ATFL ratio, the ratio of stress ATFL length to non-stress ATFL length, was calculated as an indicator of lateral ankle laxity. The Cumberland Ankle Instability Tool (CAIT), Ankle Instability Instrument (AII) and static balance tests were used to assess functional ankle impairments related to CLAI. Isometric hip abduction and ankle eversion muscle strengths, and ankle dorsiflexion angle were also evaluated. One hundred twenty ankles from 60 male soccer players (mean age, 16.4 ± 0.7 years; mean duration of playing soccer, 9.8 ± 2.4 years) were included. ILAL was detected in 63.3% (38/60) of soccer players; 28 with ipsilateral ILAL (group I) and 10 with bilateral ILAL (group Bi). Seventeen participants (28.3%; 10 from group I, 3 from group Bi, and 4 from those without ILAL) showed a CAIT score of ≤24, and 5 (8.3%; 4 from group I and 1 from group Bi) showed an AII score of ≥5. The eversion muscle strength of the ankle with ILAL was significantly weaker than the contralateral side in group I (p = 0.006). ILAL was detected in approximately two-thirds of adolescent male soccer players with relatively low CAIT and AII scores. In addition, the eversion muscle strength of the ankle with ILAL was significantly weaker than that of the contralateral side in subjects with ipsilateral ILAL. These findings suggest the possible importance of preventive interventions for soccer players with ILAL.

2 The Association of Growth and Maturation with Injury in Academy Soccer Players: A Narrative Review

Reference: Sports Med. 2025 Nov 14. doi: 10.1007/s40279-025-02340-0. Online ahead of print.
Authors: Elliott C R Hall, Robert M Erskine
Summary: The point of fastest growth during somatic maturation is termed ‚peak height velocity‘ (PHV), and the chronological age at which this occurs varies considerably. Academy football (soccer) players are typically categorised by chronological age, yet many children of the same age will naturally mature and grow at different ages and rates, respectively, which could affect injury risk. However, despite nearly two decades of studies investigating the association of growth and maturation with injury in academy footballers, confusion remains. To critically appraise the literature concerning the association of maturity timing, maturity status and growth rate with injury in academy football.
Scopus, PubMed, SPORTDiscus and CINAHL databases were screened from inception until April 2025. Study design, setting, sample size, methods for estimating maturity timing/maturity status/growth rate, and injury reporting were evaluated in this narrative review to determine individual study quality. A total of 472 articles were screened with data extracted from 26 eligible studies published between 2007 and 2025. We found that (i) early maturing players suffer more soft-tissue injuries than on-time or late maturing players; (ii) more growth-related injuries occur circa-PHV than pre- or post-PHV, but post-PHV players generally have greater injury risk than circa- or pre-PHV; and (iii) fast growth (stature increase ≥ 7.2 cm per year) increases injury risk in academy footballers. However, all eligible studies demonstrated inherent limitations and none investigated the impact of maturity timing, maturity status or growth rate on injury in female academy players, indicating future research should address these issues.

3 Impaired postural control following unanticipated single-leg landings in female soccer players with chronic ankle instability

Reference: J Biomech. 2025 Nov 7:194:113056. doi: 10.1016/j.jbiomech.2025.113056. Online ahead of print.
Authors: Shiki Takeuchi, Masaya Anan
Summary: This study investigated postural control following unanticipated single-leg landings in female soccer players with and without chronic ankle instability (CAI). Eighteen female soccer players, including 10 CAI and 8 healthy controls, participated in the study. They completed three successful 20-second single-leg stances following an unanticipated jump landing. Angular variations of the rearfoot, midfoot, and forefoot in the frontal and sagittal planes, as well as center of pressure (COP) data including total trajectory length, mean velocity, range, and time-to-boundary (TTB) in both the medial-lateral (ML) and anterior-posterior (AP) directions were collected during the single-leg stance task. The CAI group demonstrated significantly greater midfoot angular variation (0-5 s: p = 0.043; 5-20 s: p = 0.017), higher COP ML velocity (p = 0.002), and a longer COP trajectory length (p = 0.021). The mean of TTB minima in the ML direction was also significantly lower in the CAI group (0-5 s: p = 0.018; 5-20 s: p = 0.035). These findings suggest that female soccer players with CAI demonstrated impaired postural control following unanticipated landings, likely due to sensorimotor deficits. Incorporating spatiotemporal measures such as TTB may improve postural control assessments in individuals with CAI.

4 Effect of Oral and Topical Sodium Bicarbonate on Functional Recovery and Soccer-Specific Performance After Exercise-Induced Muscle Damage: A Randomized, Double-Blind, Placebo-Controlled Study

Reference: Nutrients. 2025 Oct 28;17(21):3383. doi: 10.3390/nu17213383.
Authors: William H Gurton, Lewis A Gough, Anthony Lynn, Mayur K Ranchordas
Download link: https://www.mdpi.com/2072-6643/17/21/3383
Summary: This study assessed the influence of oral and topical sodium bicarbonate (SB) on recovery and soccer-specific performance after exercise-induced muscle damage (EIMD).  In a randomized, double-blind, placebo-controlled, parallel group design, 24 soccer players were allocated to oral SB, topical SB (PR Lotion, Momentous), or placebo (PLA) (n = 8 per condition) and attended six laboratory sessions: (i) familiarization, (ii) baseline measures, and (iii) four experimental trials on consecutive days. Muscle damage was induced on day 1 using 40 × 15 m sprints, after which either 0.3 g·kg-1 body mass (BM) SB (SB-ORAL), 0.9036 g·kg-1 BM PR Lotion (SB-LOTION), or an equivalent PLA was given. Recovery outcomes were measured post-EIMD, 1 d, 2 d, and 3 d post (day 1-4). Soccer-specific performance was repeated 3 d post, with supplements administered again 2 h pre-exercise. Recovery measures included muscle soreness, vertical jump height, and maximal voluntary isometric contraction. Illinois agility test (IAT), 8 × 25 m repeated sprints, and Yo-Yo Intermittent Recovery Test Level 2 (Yo-Yo IR2) were assessed as soccer-specific performance.  Neither SB-ORAL nor SB-LOTION accelerated indices of recovery but decline in soccer-specific performance from baseline to 3 d post was attenuated for SB-ORAL, with significant effects for IAT (p = 0.032, g = 1.69) and Yo-Yo IR2 (p = 0.026, g = 1.61) compared with PLA. SB did not accelerate recovery following EIMD but prescribing oral SB before subsequent exercise might rescue key performance indicators. These findings offer implications for practitioners working with soccer players during periods where full recovery is not achieved.

5 MRI Features of Acute Muscle Injuries in Professional Soccer Players: A Systematic Review of Prognostic Associations With Return to Play

Reference: AJR Am J Roentgenol. 2025 Nov 12. doi: 10.2214/AJR.25.33710. Online ahead of print.
Authors: Eliodoro Faiella, Matteo Pileri, Valerio D’Andrea, Adriano Redi, Stefania Lamja, Domiziana Santucci, Luigi Stellato, Francesco Formiconi, Bruno Beomonte Zobel, Rosario Francesco Grasso, Umile Giuseppe Longo, Georg Ahlbäumer, Christoph Schaeffeler
Download link: https://www.ajronline.org/doi/10.2214/AJR.25.33710
Summary: In professional soccer players, muscle injuries are a primary cause of loss of time from competition and have high recurrence rates, thus posing management challenges. MRI is widely used for injury grading and prognosis, yet associations of MRI findings with return-to-play (RTP) timelines have been inconsistent. To evaluate prognostic associations with RTP duration of MRI features of acute muscle injuries in professional soccer players.  A systematic review of the PubMed and Scopus databases was conducted from January 2024 to February 2025 for studies evaluating an MRI classification system for acute muscle injuries in professional soccer players and provided quantifiable RTP outcome. Extracted information was summarized through narrative synthesis, organized according to muscle group.  The analysis included 12 studies, which evaluated a total of 961 acute muscle injuries in professional soccer players, all of whom were male. In eight studies of hamstring injuries, tendon involvement (particularly of the biceps femoris free tendon) and musculotendinous junction involvement were key findings for predicting prolonged RTP; edema had poor predictive utility. In addition, injury grades based on two different advanced MRI classification systems showed weak and moderate prognostic associations with MTP. In four studies of quadriceps injury, distal aponeurosis involvement and associated hematoma were key findings for predicting prolonged RTP beyond structural grades alone. In two studies of adductor injuries, intratendinous location, large muscle gap, and proximal injury site were key findings for predicting prolonged RTP. In one study of hip external rotator injuries, such injuries were generally mild, exhibiting a low structural grade on MRI and being associated with favorable prognosis (i.e., prompt RTP). In two studies of calf injuries, injury grade and extent of edema were key findings for predicting prolonged RTP. However, most reinjuries occurred within 2 months of RTP, commonly following low-grade injuries.  The findings highlight the role of MRI in prognostic assessments across muscle groups in professional soccer athletes with acute muscle injury.  MRI is an important, yet not standalone, component of the RTP decision-making process. Imaging, clinical, and functional criteria should be combined to inform RTP decisions.

6 Factors associated with career longevity and satisfaction: findings from the women’s soccer/football health study

Reference: Sci Med Footb. 2025 Nov 12:1-9. doi: 10.1080/24733938.2025.2584073. Online ahead of print.
Authors: Kai-Lun Law, Polly de Mille, Heidi Prather, Heidi Skolnik, Theresa A Chiaia, Cara L Lewis, Ellen Casey, Jo A Hannafin, Daphne I Ling
Summary: Female athletes have long been under-represented in sports medicine research, and data on the association of surgical procedures on elite athletic careers remain limited. This study estimated career longevity and satisfaction among elite retired women football players. Data were collected via an anonymous online survey from a previously published cohort of 560 retired elite female football athletes, who provided information on playing history, surgical history, and assessments of long-term joint function, physical activity, and general health. Linear and ordinal regression analyses were used to evaluate factors associated with career longevity, career satisfaction, and post-career satisfaction. Higher competition level was associated with longer career duration (β = 2.57, p < 0.001), while more years since retirement was linked to shorter careers (β = -0.23, p = 0.018). Playing as a defender (OR: 1.71, p = 0.035), more years since retirement (OR: 1.03, p = 0.016), and better mental (OR: 1.05, p < 0.001) and physical health (OR: 1.04, p = 0.034) were associated with greater career satisfaction. Post-career satisfaction was higher with more years since retirement (OR: 1.05, p < 0.001) and better mental health (OR: 1.14, p < 0.001), while anterior cruciate ligament (ACL) reconstruction during the career was linked to lower post-career satisfaction (OR: 0.50, p = 0.034). Retired elite women football players with more years since retirement and better mental health reported greater career and post-career satisfaction. Those with a history of ACL reconstruction reported lower post-career satisfaction, potentially due to ongoing health issues.

7 Associations between Internal Load, Respiratory Metabolism, and Neuromuscular Activation during 1v1 Small-Sided Soccer Games

Reference: J Sports Sci Med. 2025 Nov 1;24(4):934-947. doi: 10.52082/jssm.2025.934. eCollection 2025 Dec.
Authors: Juan Feng, Robert Trybulski, Piotr Makar, Dariusz Mroczek, Filipe Manuel Clemente
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12590210/pdf/jssm-24-934.pdf
Summary: Small-sided soccer games (SSGs) are widely used in football training to simultaneously improve players‘ technical skills and physical fitness. However, the mechanistic relationship among internal load, respiratory metabolism, and neuromuscular activation during SSGs remains unclear. To examine the relationship between internal load and lower-limb neuromuscular activation during 1v1 SSGs, and to determine whether respiratory-metabolism variables mediate this association. A repeated-measures design was adopted. 60 physical education students (age: 18.75 ± 0.45 years; training experience: 3.27 ± 3.3 years; body mass: 69.35 ± 8.17 kg) completed a standardized 1v1 SSG protocol (8 × 1 min bouts with 1 min passive recovery). Internal load was quantified using the Firstbeat system – training impulse per minute (TRIMP·min-1), total energy expenditure (EE_total), and heart rate (HR; average and peak) – while oxygen uptake (VO2 mL·kg-1·min-1), minute ventilation (VE, L·min-1), and respiratory rate (RespR, breaths·min-1) were continuously estimated. Surface electromyography (sEMG) was recorded bilaterally from the rectus femoris (RF) and biceps femoris (BF), normalized to maximal voluntary contraction (MVC), and analyzed for root-mean-square amplitude (RMS), averaged EMG amplitude (aEMG), integrated EMG (iEMG), and median frequency (MF). Mediation analyses were performed to assess whether respiratory metabolism parameters mediated the effect of internal load on neuromuscular activation. Internal load indices showed consistent positive correlations with respiratory-metabolic variables, ranging from r = 0.436 between EE Total and Average VO2 to r = 0.944 between Peak HR and Average VE (all p < 0.001). For BF, average VO2 VE, and RespR correlated strongly with HR (r = 0.864-0.938); for RF, TRIMP correlated significantly with Peak VO2 (r = 0.864, p < 0.001). BF metabolic indices were moderately correlated with MF (r = 0.268-0.340, p < 0.05), and RF average VO2 correlated with aEMG (r = 0.28, p < 0.05). Mediation analysis revealed that:(1) BF models: The direct effects of HR (average/peak) on BF_MF were nonsignificant. In contrast, indirect effects via RespR, VE, and VO2 were significant (p < 0.05), indicating full mediation by respiratory metabolism. (2) RF models: TRIMP·min-1 had a significant positive direct effect on RF EMG indices (RMS, aEMG, iEMG; p < 0.05) and a significant negative indirect effect via Peak VO2 (95% CI excluding 0), showing a „positive direct + negative indirect“ dual-path mechanism. (3) Energy model: The effect of EE Total on RF_aEMG was fully mediated by Average VO2 with no direct effect. Internal load and respiratory-metabolic responses showed consistent positive coupling during SSGs, forming a physiological basis for exercise performance. The BF muscle appeared to rely largely on respiratory-metabolic mediation for EMG frequency modulation, reflecting sensitivity to metabolic state. In contrast, RF activation was influenced by both direct internal load and indirect metabolic pathways. Findings suggest that BF activity may depend more on metabolic status, whereas RF activation may reflect combined influences of load intensity and metabolic mediation, providing insight for more precise assessment of load and muscle function in soccer contexts.

8 Exploring The Physiological and Physical Basis of RPE Responses in Soccer: A Comparative Analysis of Internal and External Load Determinants Across Different Training Drills

Reference: J Sports Sci Med. 2025 Nov 1;24(4):881-890. doi: 10.52082/jssm.2025.881. eCollection 2025 Dec.
Authors: Bo Tan, Anqiang Hu, Yafei Zheng
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12590205/pdf/jssm-24-881.pdf
Summary: This study investigated the relationships between Rate of Perceived Exertion (RPE) and various objective internal and external training load measures across multiple drill types in youth academy soccer players, a comparative approach that has been rarely examined. Forty-six male outfield soccer players (16.3 ± 0.4 years) from two under-17 academy-level teams competing in a city-level league, training three times per week with weekend matches, were monitored over two weeks during regular training. Data included RPE (CR-10 scale), heart rate responses (HRaverage, HRmax), and external load variables (total distance per minute, average speed, distance in Z4 [15-19 km/h], and Z5 [>19 km/h]) via Polar Team Pro, measured across all drills (3v3, 6v6, 9v9, 11v11, 10×5 positional game, repeated sprint training, muscular endurance circuit training, and slalom exercise). Aerobic capacity (VIFT) was assessed separately using the 30-15 IFT. Results indicated that RPE consistently showed large positive correlations with HRaverage (e.g., 3v3: r = 0.977) and HRmax (e.g., 3v3: r = 0.778) across most drills, Conversely, relationships between RPE and the VIFT were varied, showing large negative correlations in larger-sided games (e.g., 11v11: r = -0.446; 9v9: r = -0.585), suggesting fitter players perceived less effort. Correlations between RPE and general distance/speed metrics were inconsistent, while distances covered in high-intensity speed zones (Z4, Z5) showed large positive correlations with RPE (e.g., 3v3 Z4: r = 0.830; 3v3 Z5: r = 0.710), particularly in drills like 3v3, 6v6, repeated sprint training, and slalom. In conclusion, RPE’s relationship with training load is drill-specific. It possibly reflects physiological strain in small-sided games and conditioning drills, but shows more variable associations with external load and fitness in large-sided or tactical formats. Coaches should therefore combine RPE with objective metrics and interpret it in light of drill characteristics. These findings should be viewed cautiously given the short two-week monitoring period and absence of additional physiological markers.

9 Classifying Soccer Players Based on Physical Capacities and Match-Specific Running Performance Using Machine Learning

Reference: J Sports Sci Med. 2025 Nov 1;24(4):764-778. doi: 10.52082/jssm.2025.764. eCollection 2025 Dec.
Authors: Michel de Haan, Stephan van der Zwaard, Jurrit Sanders, Peter J Beek, Richard T Jaspers
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12590214/pdf/jssm-24-764.pdf
Summary: Sprint and endurance capacities seem to be mutually exclusive or at least at odds with each other. However, this relationship has not been investigated in soccer, which appeals to both well-developed sprint and endurance capacities. This study explores the potential of machine learning to identify soccer players based on their unique combinations of sprint and endurance capacities and sprint and endurance match-specific running performance. In this context, the relationships between sprint and endurance capacities and between physical capacities and match-specific running performance are examined in detail. Match-specific running data were collected from 31 young elite male soccer players over two consecutive seasons. Additionally, these participants underwent exercise testing, consisting of a 20-meter sprint test and an incremental treadmill test to measure maximal oxygen uptake (V̇O2max). Subgroups were identified using k-means clustering and subgroup discovery, based on players‘ sprint and endurance capacities, sprint and endurance match-specific running performance, and playing position. Three distinct subgroups were identified using machine learning: players with high sprint capacity and sprinted meters (n = 4), players with high endurance capacity and meters ran at moderate and high intensities (n = 6), and players without high physical capacities or matching match-specific running performance (n = 14). Across all players, there was no significant relationship between 20-meter sprint speed and normalized V̇O2max (R 2 = 0.085, P = 0.17), although 20-meter sprint speed was positively related to average match sprint distance (R 2 = 0.168, P = 0.03) and normalized V̇O2max to average match distance at moderate and high intensities (R 2 = 0.151, P = 0.04). In young elite soccer players, sprint and endurance capacities show positive, moderate, relationships with corresponding match-specific running performance, but those capacities do not appear to be mutually exclusive or opposing. Clustering allows for identification of players who may benefit from alternative strategic roles during matches, are at risk of overuse, or could benefit from individualized training. This method can assist coaches in designing tailored training programs and optimizing overall match strategy.

10 Modified Sprint Interval Intervention Produces Lower Inter-Subject Variability in Physiological and Performance Adaptations Across Collegiate Soccer Players

Reference: J Sports Sci Med. 2025 Nov 1;24(4):839-850. doi: 10.52082/jssm.2025.839. eCollection 2025 Dec.
Authors: Qian Peng, Zhen Zhang, Liang Gao, Hui Zhang, Yu Liu
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12590204/pdf/jssm-24-839.pdf
Summary: This experiment investigated the uniformity of the adaptations to high-intensity-interval training (HIIT) prescribed using anaerobic speed reserve (ASRHIIT [The difference between maximal sprint speed and maximal aerobic speed]), maximal aerobic speed (MASHIIT), and a load-matched sprint interval training (SIT) in male collegiate soccer players. Thirty collegiate male soccer players with 4-6 years of training experience (age = 21.6 ± 4.8 years; height = 182.4 ± 4.4 cm; body mass = 84.1 ± 3.3 kg; body fat = 13.1 ± 3.6%) were randomized to three experimental groups performing either ASRHIIT or MASHIIT (4 sets of 4-7 repetitions of 30-sec running at Δ%30ASR (MAS + 0.3×ASR) or 130% MAS, from the 1st to the 7th session) or a load-matched SIT. Participants underwent a series of lab- and field-based tests to evaluate measures of cardiorespiratory fitness (i.e., maximal oxygen uptake, cardiac hemodynamics and ventilatory threshold), anaerobic power (i.e., peak and average power), and bio-motor abilities (i.e., maximal sprint speed, change of direction, and jumping ability). Homogeneity of the adaptive changes was investigated by comparing residuals in individual changes and calculating the coefficient of variation in mean group changes. All three interventions adequately stimulated the adaptive mechanisms involved in the enhancement of the qualities mentioned above (p < 0.05). Linear sprint speed improved solely in response to SIT (p = 0.001). Moreover, load-matched SIT led to significantly greater enhancements in measures of bio-motor abilities compared to ASRHIIT and MASHIIT (p < 0.05). ASRHIIT and SIT resulted in lower inter-subject variability in adaptive responses in cardiorespiratory fitness measures (p < 0.05). Optimizing homeostatic stress through load-matched SIT leads to more homogenous adaptations across individuals and significantly greater adaptations in bio-motor abilities than the other prescription approaches. It’s worth noting that genetic variability, motivation, diet, sleep quality, and psychological factors can influence inter-individual responses. These aspects were not accounted for in the current experiment and represent potential limitations.

11 The Impact of Weekly Acceleration and Deceleration Loads on Neuromuscular Performance in Soccer: A Session-to-Session Analysis

Reference: J Sports Sci Med. 2025 Nov 1;24(4):851-860.  doi: 10.52082/jssm.2025.851. eCollection 2025 Dec.
Authors: Bo Tan, Anqiang Hu, Yafei Zheng
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12590203/pdf/jssm-24-851.pdf
Summary: This study examined weekly variations in accelerations, decelerations, and neuromuscular performance in male under-19 soccer players. It also explored the relationship between accumulated acceleration and deceleration loads and fluctuations in neuromuscular performance across a weekly microcycle. A repeated-measures observational design was used over two consecutive weeks, involving 39 outfield players monitored via Global Navigation Satellite Systems. Neuromuscular performance was assessed through countermovement jump (CMJ), hamstring strength (HS), and delayed onset muscle soreness (DOMS), measured both before and after training on five days each week, following a consistent training structure. Significant post-training reductions in CMJ (all days p < 0.001) and HS (all days p < 0.001) were observed, with the greatest impairments occurring on MD-4 and MD-5, although CMJ showed a slight rebound on MD-5 compared to MD-4. DOMS ratings peaked on MD-3 (F = 39.186, p < 0.001), indicating a buildup of midweek fatigue. The highest numbers of accelerations (F = 248.121, p < 0.001) and decelerations (F = 227.853, p < 0.001) occurred on MD-4 and MD-5. However, no statistically significant correlations were found between daily acceleration/deceleration counts and changes in CMJ or HS performance. These findings suggest that while neuromuscular performance declines progressively throughout the week, no statistically significant correlations were found between impairments and the acceleration or deceleration load of individual training sessions. Instead, the cumulative effect and timing of high-intensity training may play a more substantial role in contributing to fatigue and neuromuscular decline.

12 Phase angle and trunk muscle mass as distinguishing factors between regular and non-regular players in amateur soccer teams

Reference: J Phys Ther Sci. 2025 Nov;37(11):551-555. doi: 10.1589/jpts.37.551. Epub 2025 Nov 1.
Authors: Chiaki Matsumoto, Masahiro Ishizaka, Tatsuya Igawa, Masafumi Itokazu, Akihiro Ito
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12592226/pdf/jpts-37-11-551.pdf
Summary: This study aimed to identify the body composition characteristics that differentiate regular and non-regular players in amateur soccer teams, thereby providing objective metrics for player selection and enhancing team performance. A total of 147 male amateur soccer players (mean age 17.2 ± 4.9 years) were included and categorized as regular (n=68) or non-regular (n=79) players. Parameters of body composition including muscle mass and phase angle were measured using an InBody S10 analyzer. Groups were compared using unpaired t-tests and analysis of covariance adjusted for age, height, and weight. The regular players demonstrated significantly higher lean body mass, muscle mass, and phase angle. The trunk muscle mass and phase angle emerged as the key distinguishing variables. Logistic regression analysis revealed a significant association between phase angle and player regularity. Trunk muscle mass and phase angle are effective indicators of regular player status. Phase angle, in particular, showed utility in objective player evaluations. These findings support the integration of trunk muscle mass and phase angle into the selection criteria and conditioning protocols for amateur soccer teams.

13 Comparative Analysis of Training Load and Technical Demands in various Small-Sided Games During Soccer Preseason

Reference: Int J Exerc Sci. 2025 Nov 1;18(8):1286-1297. doi: 10.70252/QCAG3602. eCollection 2025.
Authors: Jakov Marasović, Ante Rađa, Frane Žuvela, Luka Čikotić, Marko Erceg
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12591599/pdf/ijes-18-8-1286.pdf
Summary: Small-sided games (SSG) are often used as a multifunctional form of specific training that allows development of various key components during soccer training. The main goal of this research was to determine the differences in internal and external load of different small-sided games (SSG) during preseason. The secondary goal was to analyze specific technical demands during these SSG. Twelve players of the First Croatian Junior League (U19) participated in this research in the fourth week of the preparatory period for the competitive season 2019/2020. Testing was conducted on two separate days with a day of rest in-between. Internal (IL) and external load (EL) variables and some technical demands were observed in the research. Significant differences in IL and EL were found between different types of SSG. Overall, IL (primarily HRmax (F=4.24, p<0.05, η2=0.44) and 90-100%Hrmax (F=5.18, p<0.01, η2=0.37) and EL (primarily TD (F=3.50, p<0.05, η2=0.28) and WR (F=6.26, p<0.01, η2=0.41) increased during 5vs.5 with GK (goalkeeper) series. On the other hand, greater EL (WR (F=11.43, p<0.001, η2=0.51), 2.1-3.0 m/s (F=7.03, p<0.001, η2=0.39) was observed in regular 6vs.6 while some IL parameters (%HRmax (F=6.07, p<0.01, η2=0.36) and HRmax (F=8.60, p<0.001, η2=0.44) were higher in two 6vs.6 GK series. In terms of technical demands, incidences of the PASS, RECEIVE and TURN variables were on average higher in 5vs.5 and 6vs.6 compared to 5vs.5GK and 6vs.6GK. To conclude, different SSG generated different IL and EL outcomes, especially with the addition of goalkeeper. Also, SSG could be used as a useful training tool for pre-season training in order to improve functional abilities while adding specific match-like situations for players.

14 Perceived Recovery and Muscle Fatigue in Professional Soccer Players During Preseason

Reference: Int J Exerc Sci. 2025 Nov 1;18(8):1212-1227. doi: 10.70252/ERIN2946. eCollection 2025.
Authors: Josip Maleš, Frane Žuvela, Nicola Luigi Bragazzi, Andrea De Giorgio, Goran Kuvačić
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12591601/pdf/ijes-18-8-1212.pdf
Summary: This study aimed to examine weekly variations and within-subject relationships between internal training intensity (ITI), perceived recovery (TQR), neuromuscular performance (CMJ), and perceived muscle soreness (PMS) during a four-week preseason period in professional soccer players. Twenty-three soccer players (age 24.8 ± 4.4 years; height 182 ± 7 cm; body mass 74.6 ± 6.7 kg) classified as Tier 3 athletes from the Croatian Second Soccer League were monitored using session rating of perceived exertion, TQR scales, countermovement jump tests, and PMS questionnaires. A significant reduction in ITI and concurrent improvement in TQR scores were observed across the preseason, with the highest intensity in week 1 and the lowest recovery in week 2. CMJ height performance declined during peak fatigue but rebounded as training intensity tapered. Repeated-measures correlations revealed negative associations between weekly ITI and TQR of the following week (rrm = -0.72), and between ITI and CMJ (rrm = -0.55), indicating that greater training intensities may impair both perceptual and neuromuscular recovery. The training stimulus-recovery difference index was positively associated with next-day TQR, suggesting it may serve as a sensitive marker of session-level readiness. These findings highlight the interplay between intensity, recovery, and fatigue, emphasizing the utility of low-cost subjective and objective tools for monitoring preseason responses and guiding individualized training strategies in elite soccer settings.

15 Effects of Pre-cooling and Cooling Breaks on Thermoregulatory, Physiological and Match Running Responses During Football in Moderate and Hot Temperatures

Reference: Sports Med. 2025 Nov 15. doi: 10.1007/s40279-025-02325-z. Online ahead of print.
Authors: Edgar Schwarz, Catarina B Oliveira, Monica Duarte Muñoz, Agustín Alanis, Marcela Alanis, Aldo Lara, Alfredo Freeze, Júlio A Costa, Tim Meyer, Rob Duffield
Summary: This study investigated the effects of pre-cooling and cooling breaks on thermoregulatory, hydration and running responses in football (soccer) players in moderate and hot temperatures. Forty male youth footballers participated in at least two of four matches, during which core body temperature (Tcore), heart rate (HR), match running, hydration and perceptual responses were measured. Cooling breaks (CBs), consisting of ice-cold towels and drinks, were compared to drinking breaks (DBs), consisting of passive rest and a temperate drink, applied at the same timeframes. Both were used as pre-cooling for 10 min before the warm-up, before the pre-match, during half-time and during additional 3-min cooling breaks at the 25th minute of each half. Initially, 20 players performed two crossover matches in 25 °C wet-bulb globe temperature (WBGT) receiving cooling (CB25) and drinking (DB25). A second group of 20 players played a regular match in 25 °C WBGT with no breaks (NB25) and then a match in 33 °C WBGT during which they received either cooling (CB33) or drinking breaks (DB33). In CB25, players felt cooler (p < 0.001) and less fatigued (p < 0.045) than in DB25, without differences in match running (p > 0.20), HRmean (p > 0.35) or Tcore (p > 0.09). Players in CB25 sweated less (p = 0.005) and drank less (p = 0.002), resulting in no significant difference in body mass loss compared to DB25. In CB33, players had lower HRmean (p = 0.007), similar total distance (p = 0.21), lower peak Tcore (p < 0.001) and lower body mass loss (p = 0.007) compared to NB25. In DB33, players reduced moderate (12-18 km/h; p = 0.007) and high-speed running distance (18-24 km/h; p = 0.002) but had similar peak Tcore (p = 0.71) and body mass loss (p = 0.95) to that in NB25. In general, high Tcore values and body mass losses were observed even when playing in moderate heat. Both drinking and cooling breaks attenuated the continuous Tcore rise, but using cooling also improved player perceptions in moderate temperatures. In hotter temperatures, cooling breaks further lowered Tcore and body mass loss compared to using only drinking breaks.

16 Continuous Glucose Monitoring Profiles in Elite-Level Professional European Football Players

Reference: J Diabetes Sci Technol. 2025 Nov 14:19322968251388668. doi: 10.1177/19322968251388668. Online ahead of print.
Authors: Kristina Skroce, Andrea Zignoli, Niko Mihic, David J Lipman, Lauren V Turner, Michael C Riddell, Howard C Zisser
Summary: This descriptive observational study reports on continuous glucose monitoring (CGM) data, using a novel glucose biosensor (Abbott Libre Sense Glucose Sport Biosensor), during professional game play and during daily life in elite European football players. Eighteen healthy male elite football players (age: 27.5 ± 5.1 years; height 180.1 ± 7.2 cm, weight 74.2 ± 9.1 kg, UEFA Champions League club) participated, with a subset examined for a single game for active (n = 10) and reserve (n = 4) players. Group comparisons used unpaired t-tests or Wilcoxon rank-sum tests; within-group differences used repeated measures one-way analysis of variance or Friedman test. Descriptive statistics were summarized for 24-hour data for daytime (06:00 am-10:59 pm) and nighttime (11:00 pm-05:59 am). Higher mean CGM glucose was observed during-game in active compared with reserve players (159 ± 23 vs 133 ± 25 mg/dL, P = .09), with significantly higher time above range (TAR, 72.8 ± 32.02 vs 29.7 ± 37.9%, P = .04) and lower time in range (TIR, 26.7 ± 31.9 vs 70.3 ± 37.9%, P = .04). In the 90 minute pre- to 180 minute post-game period, TAR (57.3 ± 26.6% vs 16.1 ± 20.2%, P = .02) and mean iG (149 ± 19 vs 123 ± 14 mg/dL, P = .02) remained higher for active players. For all 18 players, TIR was 89.4 ± 11.7 and 91.6 ± 13.7%, TAR was 5.9 ± 6.7 and 2.9 ± 5.7%, and time below range was 4.5 ± 10.5 and 5.3 ± 13.2% for day and night, respectively. This observational study suggests that elite European footballers may have significant increases in glycemia, as measured by CGM, supporting the notion that mild hyperglycemia can occur during and after active competition in healthy and metabolically normal athletes, perhaps because of competition stress.

17 Spare the brain: female football players‘ perspectives of heading the ball, concussion knowledge and attitudes. A qualitative study

Reference: Sci Med Footb. 2025 Nov 14:1-18. doi: 10.1080/24733938.2025.2584090. Online ahead of print.
Authors: Rebecca Blyth, Olivia Galea, Melanie Bussey, Osman Hassan Ahmed, Gisela Sole
Summary: The aim of this study was to explore female football (soccer) players‘ perspectives of heading the ball, and perceived header injury risk. A qualitative approach was undertaken using reflexive thematic analysis. Focus groups and individual interviews were conducted using a semi-structured interview guide. Participants also completed a survey containing a validated concussion knowledge and attitudes questionnaire. Participants were recruited throughout New Zealand and focus groups/interviews were completed via Zoom. Otter.ai was used to assist in transcription and NVivo was used for coding and initial theme development. Nineteen female football players were included across six focus groups and three individual interviews. Three main themes were generated. Firstly, the battle of ‚risk versus reward‘ explored players‘ views around the importance of heading for the game and perceived injury risks. Secondly, spare the brain versus train the skill described players‘ avoidance of heading the ball rather than training the skill due to potential injury risk and/or concern around performing repeated headers. Finally, changes in perspectives following concussion and appetite for managing injury risk explored how players perceived the experience of a concussion to have influenced their headers, factors influencing their concussion attitudes and potential return to heading guidelines and injury prevention tools. Female footballers reported actively avoiding repetitive header training due to their perceived injury risk and experiencing symptoms. While female players value the importance of headers for the game of football, there is also some concern around the safety and potential injury risk, especially in those with a history of concussion.

18 The multifaceted implications of mental fatigue on women’s football players‘ performance in small-sided games

Reference: Psychol Sport Exerc. 2025 Nov 11:82:103013. doi: 10.1016/j.psychsport.2025.103013. Online ahead of print.
Authors: K J Donnan, M J Bargh, L Swettenham, S Olthof, A Whitehead
Summary: Research shows that mental fatigue (MF) can negatively impact physical performance. However, the effects of MF during football match-play are not well understood, particularly in women, and its impact on psychological factors is less known (e.g., attentional focus). This study explored the physical and psychological effects of MF in women’s football during 7 vs. 7 small-sided games (SSGs). 14 Women’s National League players (M age = 25.9 ± 5.9 years) participated. A counterbalanced cross-over design was implemented involving a MF (30-min social media use), and a control condition (30-min sitting with teammates with no phone access) prior to 3 × 7-min SSGs, interspersed with 2-min rest. GPS was used to monitor work output. Participants had microphones attached and were asked to ‚think aloud‘ (TA) during SSGs; content analysis was used to examine players‘ attentional focus and communication. MF (visual analogue scale) and fatigue (BRUMS) increased pre-to post-MF (+1.95 ± 1.45, p < .001; +2.57 ± 3.33, p = .038) but in control (p = 1.00), and happiness (BRUMS) was lower in MF vs. control (-1.96 ±0 .68, p = .013). No differences were found between conditions for work output or RPE (ps > 0.05). Total TA was lower (p = .046) and there was less positive performance-related TA (p = .022) in MF (22.53 ± 13.11; 0.15 ± 0.38) vs. control (30.00 ± 17.84; 1.54 ± 2.11). There was more negative non-performance related communication (p = .031), and less joking with teammates (p = .020) with MF (0.85 ± 1.07; 1.69 ± 1.80) vs. control (0.08 ± 0.28; 4.39 ± 3.78). In sum, 30-min social media use was associated with reduced happiness, vigour and heightened perceptions of fatigue, and effected how able participants were to engage in TA, how positive their thoughts were, and how they communicated with teammates. Avoiding phone use prior to training and match-play may be worth considering. Further team-sport research could incorporate TA methods which the present study showed to be feasible, to understand more on players‘ cognitive processing in match-play.

19 Can Sled-Resisted Priming Training Enhance Performance in Amateur Football Players?

Reference: Sensors (Basel). 2025 Oct 25;25(21):6575. doi: 10.3390/s25216575.
Authors: Alvaro Medina-Sanchez, Jose Luis Felipe, Jorge Garcia-Unanue, Leonor Gallardo, Antonio Alonso-Callejo
Download link: https://www.mdpi.com/1424-8220/25/21/6575
Summary: This study examined the acute and chronic effects of sled-resisted training on power, strength, jump height (evaluated through a CMJ), and sprint kinematics in Spanish amateur football players. A total of 19 football players (28 ± 8 years; 172 ± 12 cm; 79.3 ± 22.3 kg) performed 10 sled-resisted training sessions with loads of 80% (±2 kg) of their body mass on the day before the match (MD-1). Performance was assessed using a CMJ measured with the My Jump Lab app and sprint kinematics recorded with the 1080 Sprint system; both of these sensor-based technologies are validated for sports performance analysis. The CMJ was performed on MD-1 before the training and again on match day. Sprinting was evaluated before the sled-resisted training and again one week after it ended. These results suggest that sled training with heavy loads and low volume may not have acute effects on CMJ in amateur football players 24 h after it is performed, but there are chronic improvements in CMJ relative force and changes in sprinting after 10 weeks of sled-resisted training. The findings of this study will enable football coaches and physical trainers to understand the changes in this training method to improve performance in amateur football players, using only three repetitions per player per week.

20 Applying the principles of risk management in male professional football: a feasibility study, introducing the Aspetar sports injury and illness risk management tool

Reference: Br J Sports Med. 2025 Nov 12:bjsports-2025-110063. doi: 10.1136/bjsports-2025-110063. Online ahead of print.
Authors: Bahar Hassanmirzaei, Montassar Tabben, Yorck Olaf Schumacher, Hafid Mammeri, Mokhtar Chaabane, Raouf Nader Rekik, Rui Drumond, Souhail Chebbi, Roald Bahr
Summary: Risk management in sports aims to minimise injury and illness risks while optimising athlete performance through systematic identification, assessment and mitigation strategies. Existing frameworks offer theoretical guidance, but practical tools for consistent implementation are not available. Our objective was to develop, identify and evaluate the implementation feasibility of a practical tool for identifying, prioritising and mitigating injury and illness risk in male professional football clubs in Qatar. All 18 professional clubs in Qatar participated in a league workshop introducing the risk management plan (RMP) tool before the 2022-2023 season. Teams then engaged in structured risk assessment workshops involving medical and technical staff, identifying risks categorised as team, player or season related. Risk priority was determined using a standardised scoring system, and tasks were allocated among the responsible parties to reduce risk. All 18 clubs implemented the newly introduced RMP tool. A total of 809 risks were identified across all teams (45 risks per team), with player-related risks accounting for the majority (72%). Teams prioritised 265 (33%) of the identified risks for mitigation, with individualised training programmes, communication strategies and load management being the most frequently planned interventions. Task implementation involved a collaborative approach to risk mitigation, including 58 individuals (4.2±2.1 per team) across medical and technical roles. The Aspetar RMP tool was adopted by all Qatar’s clubs, facilitating a structured approach to injury and illness risk identification and management. Identifying risk profiles and planning mitigation tasks reflected a mix of player-specific and team-level actions, and a collaborative approach involving both medical and technical staff.

21 Painkiller use in amateur football: high prevalence, but limited misuse

Reference: BMC Sports Sci Med Rehabil. 2025 Nov 11;17(1):325. doi: 10.1186/s13102-025-01396-9.
Authors: Andreas Kopf, Werner Krutsch, Dominik Szymski, Johannes Weber, Volker Alt, Hermann Josef Bail, Markus Geßlein, Johannes Ruether, Lorenz Huber
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12604260/pdf/13102_2025_Article_1396.pdf
Summary: The use of painkillers in football is a much-criticized topic, but there is hardly any scientific data at amateur level. The aim of the study is therefore to establish data on the prevalence of painkiller use in German amateur football. In addition, reasons for painkiller use and other influencing factors are investigated. In a cross-sectional analysis, the painkiller use among German amateur footballers was surveyed through an online protocol, involving players from the 4th league to the lowest amateur divisions. Of the 604 participants, 489 were male (81.0%) and 115 were female (19.0%). The prevalence of painkiller use over the players‘ entire careers in connection with football is approximately 77%. 75% of players report using painkillers only for acute injuries, with over two-thirds rarely or never taking them before a game. At 80%, female players report slightly higher painkiller use for acute injuries than male players (74.4%, p = 0.19). Age-related differences show that older players take painkillers more frequently than younger players (p < 0.001). Furthermore, league-specific differences show that higher playing levels (4th league) are associated with higher pain prevalence and higher painkiller use compared to the lowest five leagues (p < 0.001). This is the first study to record the use of painkillers in amateur football from the players‘ perspective with a large sample size. The lifetime prevalence of painkiller use among amateur football players in this study matches levels found in previous studies of amateur and professional sports. Most players take painkillers for medically justified reasons, with misuse being minimal. However, a minority of players show less responsible usage. Further research into the contextual factors influencing painkiller use is needed, and educational initiatives are important to improve awareness regarding pain management in football.

22 Adductor strengthening programme improves groin injury risk factors in youth football players

Reference: Res Sports Med. 2025 Nov 11:1-14. doi: 10.1080/15438627.2025.2577893. Online ahead of print.
Authors: Jibing Wang, Yujia Zhai, Nannan Liu, Guoyan Zhang, Duona Wang
Summary: This randomized controlled trial evaluated an 8-week adductor strengthening programme on improving groin injury risk factors in youth football players. Fifty-four youth players (23 female, 43%) were randomized into an intervention group (n = 27, performing two weekly adductor sessions before regular training) and a control group (n = 27, regular training only). The intervention group showed significantly greater improvements than controls in bilateral eccentric hip adduction strength (EHADS) (left: mean difference (MD) = 0.28; right: MD = 0.27, Nm/kg, p < 0.001) and EHADS: eccentric hip abduction strength ratios (left: MD = 0.07; right: MD = 0.06, p < 0.05), with female players showing higher increases than males in left-side EHADS (31.9% vs. 14.4%, p = 0.004). The intervention group showed statistically significant improvements in the Hip and Groin Outcome Score subscales (symptoms, participation in physical activities, quality of life, p < 0.05), but not the control group (p > 0.05). The programme effectively improves groin injury risk factors, particularly benefiting female athletes, and should be integrated into youth football training.

23 Methodological Insights Into the Acceleration-Speed Profile: Optimizing Data Analysis for Reliable Application in Elite Female and Male Football

Reference: Int J Sports Physiol Perform. 2025 Nov 8:1-8. doi: 10.1123/ijspp.2025-0292. Online ahead of print.
Authors: Antonio Alonso-Callejo, Jose Maria Manzano, Jorge Garcia-Unanue, Marc Guitart, Berta Carles, Leonor Gallardo, José Luis Felipe
Summary: This study aimed to evaluate the reliability of the acceleration-speed profile in elite male and female football players across 3 competitive seasons. Specifically, we assessed how the number and type of microcycles influence the reliability of theoretical maximal acceleration (A0) and speed (S0). GPS-derived acceleration and speed data were collected from 181 women’s and 146 men’s microcycles. Acceleration-speed profiles were constructed using overlapping windows of 1 to 5 consecutive microcycles, classified as competitive, including match day (MD) or post-MD (MD + 1) or noncompetitive, not including MD or MD + 1. Linear regressions were applied to estimate A0 and S0. Theoretical maximal acceleration and S0 increased with longer microcycles but plateaued beyond 5 days. Grouping by 2 microcycles showed the highest reliability for both A0 and S0 in male and female players. Competitive profiles consistently outperformed noncompetitive profiles in terms of stability and signal quality across both sexes. Male players demonstrated lower variability and higher signal-to-noise ratios than female players. The most reliable acceleration-speed profiles can be obtained from 2 consecutive microcycles, each including 5 or more sessions and at least 1 MD or MD + 1. These findings support the integration of in situ sprint profiling into applied performance monitoring without the need for isolated testing.