Latest research in football – week 45 – 2026

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 the Compensatory Training Strategy on External Speed Load Between Starter and Nonstarter Soccer Players

Reference: Int J Sports Physiol Perform. 2026:1-6. doi: 10.1123/ijspp.2026-0298.
Authors: Giovanni S. Ramirez, Laura A. Zandavalli, Fábio Y. Nakamura, Giovani S. Cunha, Valdir N. de Oliveira Júnior, Rafael Grazioli, Eduardo L. Cadore
Summary: The aim was to evaluate the efficacy of postmatch compensatory training (CT) in mitigating disparities in external speed load between nonstarters (with varying match exposure) and starters (>60 min match play without CT). Forty-three professional soccer players (25 [4] y) were monitored across 68 matches using global positioning system. Players were classified as starters (G1, >60 min), nonstarters (G2, 0 min), and nonstarters (G3, 1-30 min). External load metrics included total distance, high-speed running (HSR), and sprint distance, analyzed as both absolute values and relative values (% of total distance covered, and per minutes played). CT consisted of high-intensity interval exercise (∼925 m). Generalized estimating equations with least significant difference post hoc tests were applied (P < .05). Significant group × intervention interactions were observed for HSR and sprint distance (P ≤ .002). Without CT, G1 showed higher HSR (585 vs 33-143 m) and sprint distance (115 vs 2-34 m) than G2 and G3 (P < .05). Following CT, both G2 and G3 markedly increased HSR (G2: 33→261 m; G3: 143→318 m; P ≤ .001), reducing differences versus G1. Sprint distance increased in G2 (2→75 m; P < .001), although G1 remained higher than G2 and G3 (P ≤ .05). Relative metrics confirmed these findings, with no between-group differences after CT. Total distance remained higher in G1 across conditions (P < .001). Postmatch CT effectively attenuates external speed-load disparities between nonstarters and starters in professional soccer players.

#2 How soccer team students shape adolescent athlete engagement: evidence from an actor-partner interdependence model

Reference: Front Public Health. 2026 Aug 20:14:1904710. doi: 10.3389/fpubh.2026.1904710. eCollection 2026.
Authors: Haopeng Wang, Huarui Huang, Chen Zhong, Yizhou Shui
Summary: Physical inactivity among adolescents has become a global public health concern. Insufficient engagement in sports potentially affects physical and mental health. Athlete engagement, reflecting persistent positive emotional experiences in physical activity, is a key factor in promoting adolescent development. This study investigates how adolescent athlete participation influences athlete engagement within and across different student groups. A total of 4,140 students from 167 soccer-featured schools in China are recruited, comprising 2,070 soccer team students and 2,070 non-soccer team students. Participants complete the Athlete Participation Scale (APS) and the Athlete Engagement Questionnaire (AEQ). Data are analyzed using descriptive statistics, correlation analysis, and the Actor-Partner Interdependence Model (APIM) with latent variables to examine actor and partner effects. Soccer team students exhibit a significant actor effect on their own engagement (β = 0.824, p < 0.001). However, they do not have a significant partner effect (β = -0.005, p > 0.05). In contrast, non-soccer team students exhibit a statistically significant actor effect. However, the effect size is small (β = 0.045, p < 0.05). Meanwhile, the partner effect is significant (β = 0.518, p < 0.001). The partner effect is stronger than the actor effect. The dyadic pattern analysis classifies the pattern for soccer team students as an actor-only pattern and the pattern for non-soccer team students as a mixed actor-partner pattern. Athlete participation influences adolescent athlete engagement differently across student groups. Soccer team students‘ athlete engagement is mainly driven by their own athlete participation. For non-soccer team students, their own athlete participation has only a limited effect on their athlete engagement. Non-soccer team students are more strongly influenced by the role-modeling of soccer team students. These findings highlight the value of strengthening campus soccer teams to mobilize non-soccer team students‘ sustained engagement in physical activity.

#3 High Rates of Return to Soccer After Primary Hip Arthroscopic Labral Repair for Femoroacetabular Impingement Syndrome

Reference: Arthrosc Sports Med Rehabil. 2026 Sep 2:e70072. doi: 10.1002/ars2.70072. Online ahead of print.
Authors: Akeem Henry, Louis Kang, John-Rudolph Smith, Malik Dancy, Gavin Ward, Bruce A Levy, Mario Hevesi, Aaron J Krych, Kelechi R Okoroha
Summary: The purpose was to evaluate return-to-sport (RTS) outcomes and patient-reported outcomes in soccer players after primary hip arthroscopic labral repair for femoroacetabular impingement syndrome. All patients undergoing primary hip arthroscopy with labral repair for femoroacetabular impingement syndrome from 2011 to 2022 were retrospectively reviewed. Patients who had a minimum 2-year follow-up, played soccer, and had no prior hip surgery were included. Patient-reported outcome measures and RTS were collected at the final follow-up. Logistic regression was used to assess associations between potential covariates (e.g., age, sex, and level of play) and RTS. Forty-eight hips in 41 patients (21 men [51%]) with a mean age at surgery of 21.9 years (range 13-41 years) were included. Thirty-two out of the 41 patients (78%) played at either the recreational or high school level. After removing those who did not return for nonmedical reasons, 29 out of 36 (81%) patients were able to return to soccer. Among patients with available patient-reported outcome measures, significantly greater postoperative scores were seen in the RTS group for Hip Outcome Score-Activities of Daily Living (95 vs 85) and Hip Outcome Score-Sport (88 vs 71, both P < .05). Soccer players younger than 25 years had significantly higher odds of RTS compared with those aged 25 years or older (odds ratio = 8.8, P = .006). Five hips (10%) underwent revision at the final follow-up. Soccer players undergoing primary hip arthroscopic labral repair for femoroacetabular impingement syndrome reported an 81% RTS rate at a minimum 2-year follow-up, with most returning at the same or higher level of play. At a mean follow-up of 5.5 years, most patients achieved Patient Acceptable Symptom State thresholds. Younger age was associated with a higher likelihood of return to sport.

#4 Acute Effects of Contract-Relax PNF With and Without Neuromuscular Electrical Stimulation on Hamstring Flexibility and Jump Performance in Adolescent Soccer Players: A Randomized Controlled Trial

Reference: Int J Sports Phys Ther. 2026 Sep 1;21(9):808-820. doi: 10.26603/001c.166783. eCollection 2026.
Authors: Carlos Salvador-Huerta, Pedro Azanon-Nogueira, Eloi Suárez-Pazos, Valeria Betancourt-Cabeza, Irene Lazcano-Nogueira, Andrea Porcu, Ángel Manuel de la Hera-Sastre, Juan J Amer-Cuenca, Juan Francisco Lisón
Summary: The additional value of neuromuscular electrical stimulation (NMES) during contract-relax proprioceptive neuromuscular facilitation (PNF-CR) stretching remains unclear, particularly in adolescent athletes. It is also unknown whether combining PNF-CR with motor-threshold NMES improves hamstring flexibility more than a sensory-threshold comparator without impairing vertical jump performance. The aim was to compare the acute effects of PNF-CR combined with motor-threshold NMES versus sensory-threshold NMES on hamstring flexibility and to assess the impact of both interventions on vertical jump performance. Randomized controlled trial. Forty-seven youth soccer players (mean age: 13.2 ± 1.8 years) were randomly assigned to one of two groups. Both groups received the same single-session PNF-CR stretching protocol. The experimental group (n = 23) received motor-level NMES during the contraction phases, whereas the placebo group (n = 24) received sensory-level NMES during the same PNF-CR protocol. Hamstring flexibility was assessed using the Popliteal Angle (PA) and Sit-and-Reach (SR) tests, while vertical jump performance was evaluated via the Countermovement Jump (CMJ) test. Analyses followed an intention-to-treat approach. Time, group, and time × group effects were examined using two-way repeated-measures ANOVA with Bonferroni-adjusted post hoc comparisons; CMJ was additionally analyzed using ANCOVA adjusted for baseline values. Both groups showed statistically significant pre-post improvements in SR and PA scores. Specifically, PA decreased in the experimental group by 4.0° (95% CI: 1.4 to 6.5; p = 0.003) and by 3.1° (95% CI: 0.5 to 6.0; p = 0.018) in the placebo group. SR increased by 2.7 cm (95% CI: 1.9 to 3.6; p < 0.001) in the experimental group and 2.8 cm (95% CI: 1.9 to 3.7; p < 0.001) in the placebo group. No significant between-group differences were found for either flexibility outcome. Regarding CMJ, no significant intra- or intergroup changes were observed (p > 0.05). The addition of motor-threshold NMES to a PNF-CR stretching protocol does not yield superior acute flexibility gains. Moreover, neither intervention negatively affected jump performance in this athletic population, supporting their safe and potentially beneficial application in pre-training contexts for adolescent soccer players.

#5 Do elite soccer players meet nutritional requirements? A scoping review and meta-analysis

Reference: BMC Nutr. 2026 Aug 13;12(1):185. doi: 10.1186/s40795-026-01439-5.
Authors: Pedro Miguel Mendes, Diogo Vicente Martinho, Alain Massart, César Leão, Rodrigo Abreu, Cristian Petri, Vítor Hugo Teixeira, Adam Field, Néstor Ordoñez-Saavedra, Hugo Sarmento
Summary: This scoping review and meta-analysis synthesised current evidence on energy and macronutrient intake and energy expenditure in elite male and female soccer players. Despite established nutritional guidelines, concerns persist regarding chronic low energy availability and its implications for both performance and health. A total of 57 studies involving professional and semi-professional athletes aged 16 years and older were included. Meta-analyses were conducted for energy intake and total energy expenditure, with analyses performed separately for male and female players. Evidence was also synthesised for dietary intake, including carbohydrate, protein, and fat consumption. Energy intake and expenditure comparisons were based on 11 studies in male players and 6 in female players. Across both sexes, findings consistently demonstrated negative energy balance. Male players exhibited significant intake deficits relative to expenditure, averaging up to – 741 kcal.day⁻1, while female players showed deficits of – 544 kcal.day⁻1 (both p < 0.01). Even after adjustment for estimated underreporting (~ 19%), substantial energy gaps persisted, particularly among males. Carbohydrate intake was derived from 26 studies in male players (pre-season: 5.42 g.kg⁻1.day⁻1; in-season: 4.62 g.kg⁻1.day⁻1) and 7 studies in female players (3.79 g.kg⁻1.day⁻1). Protein intake was based on 25 studies in male players (1.78 g.kg⁻1.day⁻1) and 8 studies in female players (1.57 g.kg⁻1.day⁻1). Overall, carbohydrate and protein intakes generally aligned with the lower end of UEFA recommended ranges, with more pronounced inadequacies observed in female players, while fat intake was consistent with established nutritional guidelines. These findings emphasise the need for more rigorous, sex-specific investigations to underpin evidence-based nutritional strategies in elite soccer, thereby bridging the gap between research and practice while safeguarding both performance and athlete well-being.

#6 Comparative return to play and performance outcomes following lower extremity injuries in European professional soccer: a systematic review and meta-analysis

Reference: Phys Sportsmed. 2026 Sep 5:1-10. doi: 10.1080/00913847.2026.2726181. Online ahead of print.
Authors: Abdoul Mbengue, William Galardi, Camryn McIntyre, William Woodhams, Taylor Wesley, Darby Dean, Victoria Vespa, Doyle Ford, Shivam Patel, Allison Tenfelde
Summary: Lower extremity injuries are common in professional soccer and can significantly impact return to play (RTP) and player performance. While individual injuries have been studied, comparative data across injury types remain limited. To systematically evaluate return to play rate (RTPR), return to play time (RTPT), and post-injury performance outcomes following lower extremity injuries in professional European soccer players. Systematic review and meta-analysis; Level of evidence, 4. A systematic search of PubMed and Embase was performed in accordance with PRISMA guidelines, covering database inception through May 2026 (initial search conducted January 2024; updated May 2026). Studies evaluating professional European soccer players with lower extremity injuries and reporting RTP outcomes were included. Primary outcomes were RTPR and RTPT. Secondary outcomes included post-injury performance metrics. A random-effects meta-analysis of proportions was performed for anterior cruciate ligament (ACL) injuries and Achilles tendon ruptures. Twenty-nine studies met inclusion criteria. ACL injuries demonstrated RTPR ranging from 80% to 95%, with RTPT of 215-267 days, and were associated with persistent declines in performance metrics, including minutes played and offensive production. Achilles tendon ruptures had RTPR of 70% to 78% and RTPT of 119-161 days, with significant short-term reductions in performance. Meniscus and medial collateral ligament (MCL) injuries demonstrated lower RTPR (approximately 70%) but shorter recovery timelines. Adductor and hamstring injuries were associated with the shortest RTPT (approximately 15-24 days) and minimal long-term performance decline. Meta-analysis demonstrated a pooled RTPR of 90.3% (95% CI, 81.2%-95.2%; I2 = 70.6%) for ACL injuries and 76.6% (95% CI, 69.2%-82.7%; I2 = 0%) for Achilles tendon ruptures. Among lower extremity injuries in professional European soccer, ACL injuries and Achilles tendon ruptures are associated with the greatest impact on RTP and player performance, whereas muscle injuries are associated with faster recovery and less sustained performance decline. As all included studies were observational, these findings represent associations rather than causal relationships and should be interpreted accordingly. These findings may assist clinicians and teams in prognostication and return-to-play decision-making.

#7 Baseline cognitive performance moderates ACL injury-related knee biomechanics during unanticipated sidestep cutting in highly trained male soccer players

Reference: Front Physiol. 2026 Aug 18:17:1911093. doi: 10.3389/fphys.2026.1911093. eCollection 2026.
Authors: Weipeng Liu, Zilong Wang, Zhuangzhuang Wang, Zhiyuan Qin, Zhengwei Wu, Weihua Zheng, Congjie Cheng, Weichao Li, Wenhua Li
Summary: The purpose was to compare anterior cruciate ligament (ACL) injury-related knee biomechanics between anticipated and unanticipated sidestep cutting and to investigate whether baseline cognitive performance moderated these biomechanical responses in highly trained male soccer players. Thirty highly trained male soccer players completed a computerized Go/No-Go task to assess inhibitory control, including reaction time (RT), commission error rate (CER; responses incorrectly made during No-Go trials), and omission error rate (OER; failures to respond during Go trials). Participants subsequently performed anticipated and unanticipated 90° sidestep cutting tasks while three-dimensional motion capture and force plate data were simultaneously collected. Peak knee flexion angle, peak knee abduction angle, peak knee abduction moment, peak anterior tibial shear force (ATSF), peak vertical ground reaction force (vGRF), and loading rate were analyzed. Paired comparisons were first performed to examine overall biomechanical differences between the anticipated and unanticipated conditions. Linear mixed-effects models were then used to investigate whether cognitive performance moderated the biomechanical responses to task anticipation. Compared with the anticipated condition, unanticipated sidestep cutting resulted in greater peak knee flexion angle (d = 0.389, 95% CI, 0.118-0.660, p = 0.006), peak knee abduction angle (d = 0.339, 95% CI, 0.189-0.489, p < 0.001), and peak knee abduction moment (d = 1.481, 95% CI, 0.857-2.104, p < 0.001). Significant anticipation × RT interactions were observed for peak knee abduction angle (β std = 0.156, 95% CI, 0.039-0.274, p = 0.031), peak knee abduction moment (β std = 0.380, 95% CI, 0.168-0.592, p < 0.001), and peak ATSF (β std = 0.517, 95% CI, 0.350-0.684, p < 0.001). Significant anticipation × CER and anticipation × OER interactions were observed for peak knee abduction moment (β std = 0.504, 95% CI, 0.299-0.710, p < 0.001) and peak vGRF (β std = 0.463, 95% CI, 0.245-0.682, p < 0.001), respectively. Unanticipated sidestep cutting altered multiple ACL injury-related biomechanical variables in highly trained male soccer players. More importantly, athletes‘ baseline cognitive performance moderated several ACL injury-related biomechanical responses.

#8 Repeated sprint performance and fatigue responses across different movement patterns in amateur soccer players

Reference: BMC Sports Sci Med Rehabil. 2026 Aug 22;18(1):387. doi: 10.1186/s13102-026-02017-9.
Authors: Erhan Işıkdemir, Mehmet Emre Kılıç, Fevzican Kelebek
Summary: The objective of this study was to examine the differences in neuromuscular fatigue, physiological responses, and physical performance between the Curved (Bangsbo) Repeated Sprint Ability Test (C-RSA) and the Linear Repeated Sprint Ability Test (L-RSA) in amateur soccer players. Fourteen amateur male soccer players (mean age: 19.8 ± 1.4 years) voluntarily participated in this randomized, counterbalanced crossover study. Participants completed the C-RSA and the L-RSA in a randomized and counterbalanced order, with a 72-hour recovery period between testing sessions. Neuromuscular fatigue was evaluated through the countermovement jump test performance (CMJ) administered before and after the protocols, and change score were calculated. Physical performance was analyzed using total sprint time (TST), mean sprint time (MST), best sprint time (BST), and sprint decrement percentage (SDec %). Physiological responses were determined via maximum heart rate (HRmax), blood lactate levels (La- 1), and the rating of perceived exertion (RPE). Data were analyzed using paired samples t-tests, and effect sizes were calculated using Cohen’s d and interpreted according to Hopkins‘ classification. The findings indicated that both test protocols induced neuromuscular fatigue. Although a greater reduction in CMJ was observed following the C-RSA, the difference between conditions was not statistically significant (p = 0.085; small effect). Regarding physiological responses, no significant differences were found in HRmax and La levels (p > 0.05); however, RPE values were significantly higher in the C-RSA (p = 0.003; moderate effect). In terms of physical performance parameters, significant differences were identified in favor of the L-RSA. The L-RSA provided higher performance outputs in TST, MST, and BST variables with very large effect sizes (p < 0.001). No significant difference was observed in the SDec % (p = 0.052). In conclusion, although the C-RSA and L-RSA protocols elicited similar physiological loads, the C-RSA induced higher neuromuscular and perceptual stress, whereas the L-RSA protocol was more advantageous for physical performance output. These findings suggest that linear and curved sprint applications generate distinct performance responses, and sprint pattern-specific loading should be considered in training planning.

#9 Mechanism-based nutritional strategies for performance and recovery in soccer players: a qualitative research synthesis

Reference: J Strength Cond Res. 2026 Dec 30;23(1):2721836. doi: 10.1080/15502783.2026.2721836. Epub 2026 Sep 1.
Authors: Amir Hossein Azizi Ammarati, Zohreh Shanazari, Masoud Rahmati
Summary: Modern soccer, characterized by its intermittent high-intensity nature, requires a combination of explosive power and aerobic endurance. This physiological demand results in substantial metabolic load, oxidative stress, and disruption of recovery processes in players. Multi-target nutritional supplements may therefore provide critical support in maintaining performance and accelerating recovery. This qualitative review synthesizes current evidence regarding the efficacy of melatonin, gut-axis interventions (prebiotics, probiotics, and synbiotics), magnesium, sodium pyruvate, and purple grape-derived products on performance and recovery outcomes in soccer players. Twenty-two interventional studies conducted on soccer players were systematically extracted and qualitatively synthesized following PRISMA 2020 reporting guidelines. Methodological quality and risk of bias were assessed using design-specific tools, including the Cochrane Risk of Bias 2 (RoB 2) tool for randomized controlled trials and the ROBINS-I framework for non-randomized intervention studies. Overall certainty of evidence was evaluated using an adapted GRADE framework. Particular attention was directed to study design, dosage and timing protocols, performance and biochemical outcomes, and methodological limitations, with emphasis placed on linking mechanistic evidence with applied performance and recovery outcomes. Melatonin, administered either nocturnally or prior to exercise, was associated with reductions in oxidative stress markers and upregulation of antioxidant enzymes, contributing to attenuation of short-term performance decline; however, its effects on maximal performance indices were inconsistent. Prebiotic, probiotic, and synbiotic interventions enhanced mucosal immunity and reduced the incidence and duration of upper respiratory tract infections (URTI) as well as delayed onset muscle soreness (DOMS). Certain combined formulations-particularly those co-administered with protein or spirulina-also demonstrated improvements in body composition and muscular strength. Magnesium supplementation alone showed limited and inconsistent benefits in athletes without deficiency, although combined formulations indicated potential improvements in buffering capacity and anaerobic performance. Short-term sodium pyruvate supplementation supported ATP-PCr system resynthesis and enhanced repeated sprint performance. Purple grape-derived products increased serum antioxidant capacity and, in some participants, improved endurance performance. Key limitations across studies included small sample sizes, protocol heterogeneity, and a lack of standardized mechanistic biomarkers. Overall, these supplements may support performance and recovery in soccer players; however, larger-scale, field-based randomized controlled trials are required to establish precise, evidence-based operational strategies.

#10 Sun exposure and photoprotection: Habits, knowledge, and attitudes among elite beach soccer players

Reference: Photochem Photobiol. 2026 Sep 1. doi: 10.1111/php.70148. Online ahead of print.
Authors: Guillermo De Castro-Maqueda, Pau Vaccaro-Benet, Miguel Ángel Rosety Rodríguez, Macarena Rivero Vila
Summary: Beach soccer players are exposed to prolonged ultraviolet radiation (UVR) due to the outdoor nature of the sport, minimal clothing coverage, and frequent participation in coastal environments with highly reflective surfaces. This study aimed to evaluate sun exposure habits, photoprotection practices, attitudes, knowledge related to skin cancer prevention, and the prevalence of sunburn episodes among elite beach soccer players. A cross-sectional observational study was conducted during the European Beach Soccer Qualifying Championship held in October 2025. A total of 257 elite male players from 21 European countries completed a standardized questionnaire assessing UVR exposure, photoprotection behaviors, sun-related attitudes, knowledge, and skin surveillance practices. Overall, 76% of athletes reported at least one sunburn during the previous sports season, and 35% experienced three or more episodes. Although 84% reported regular sunscreen use and 93% used products with a sun protection factor (SPF) ≥30, only 31% reported reapplying sunscreen every 2 h as recommended. Positive attitudes toward tanning remained common, while the overall knowledge score regarding skin cancer prevention was moderate (6.7 ± 1.6 points out of 10). In addition, 72% of players did not regularly perform skin self-examinations. These findings indicate that elite beach soccer players represent a high-risk population for UVR-related skin damage and highlight the need for targeted photoprotection and skin cancer prevention strategies.

#11 Effects of carbohydrate mouth rinse on psychophysiological responses, kinematic variables and technical actions during small-sided soccer games

Reference: J Int Soc Sports Nutr. 2026 Dec 30;23(1):2726524. doi: 10.1080/15502783.2026.2726524. Epub 2026 Sep 1.
Authors: Erdinc Gorgulu, Yusuf Soylu, Ersan Arslan, Bulent Kilit, Neil D Clarke
Summary: This study investigated the effects of carbohydrate mouth rinsing (CHOMR) on various psychophysiological, kinematic, and technical actions during 4-a-side small-sided soccer games (SSGs). In a randomized, crossover, double-blind design, 16 young male soccer players (age: 15 ± 1 years; height: 172.6 ± 7.0 cm; body mass: 57.8 ± 7.9 kg) participated in two 4-a-side SSGs separated by one week following either CHOMR or placebo (PLA). During each SSGs, heart rate (HRmean, %HR, and HRmax), rating of perceived exertion (RPE), enjoyment, visual analogue scale (VAS) to perceived mental fatigue, mood states, total distance (TD), high-speed running distance (HSRD), average metabolic power (AMP), high metabolic load distance (HMLD), sprint distance (SD), acceleration (ACC), deceleration (DEC), and technical actions (e.g. passing, tackling, shooting, and interceptions) were assessed. Compared with PLA, CHOMR resulted in significantly higher RPE (p = 0.025, g = 0.86) and significantly lower VAS scores (p = 0.010, g = -0.71). In addition, the CHOMR condition showed significantly higher values for interceptions, successful tackles, unsuccessful tackles, unsuccessful shots, and goals (p < 0.05, g = 0.96-2.02), whereas block values were significantly higher in the PLA condition. There were no statistically significant differences in HRmean, %HR, HRmax, enjoyment, TD, HSRD, AMP, HMLD, SD, ACC, DEC, successful passes, unsuccessful passes, successful shots, or mood states between the conditions (p > 0.05). The current study findings suggest that CHOMR may enhance selected technical actions and lower VAS scores during 4-a-side SSGs, although it was also associated with higher RPE and did not alter the kinematic responses. In conclusion, CHOMR was associated with higher RPE, lower mental fatigue, and selective improvements in technical actions, with no significant effects on kinematic variables or HR.

#12 Timing and Dose Matter: Late High-Speed Exposure and Higher High-Intensity Acceleration Volumes Reduce Hamstring Reinjury Risk in Elite Male Football (Soccer)

Reference: J Orthop Sports Phys Ther. 2026 Sep;56(9):611-621. doi: 10.2519/jospt.2026.14077.
Authors: Javier Pecci, Christian Castilla-López, Rocco di Michele, Luca Benedetti, Paolo Aiello, Nicolò Prandelli, Gianni Nanni, Luca Bini, Adolfo Muñoz-Macho, Manuel Alcantarilla-Pedrosa, Bartomeu Llabrés-Bennasar, Ioannis Stathas, Nikolaos Koundourakis, Jose Asian-Clemente, Bartosz Bibrowicz, Angel Carnero-Díaz, Marco Beato, Borja Sañudo, Paolo Perna
Summary: The aims of this study were to (a) investigate whether the timing and magnitude of exposure to high-speed running (HSR), sprinting, and high-intensity accelerations during on-field rehabilitation after hamstring strain injury were associated with reinjury risk and (b) examine changes in match running performance upon return to play (RTP). Retrospective cohort study. Data from 95 elite male football (soccer) players from five professional clubs competing in major European and Middle Eastern leagues were analyzed. Players with complete rehabilitation load profiles were included in the 2-month and 6-month reinjury analysis. Modified Poisson regression assessed associations between rehabilitation load characteristics and reinjury risk. Match running performance (HSR distance, sprint distance, and high-intensity accelerations per minute) during the five matches before injury and the first five matches after RTP was compared using paired t-tests for the entire cohort. Late introduction of HSR, sprinting, and high-intensity accelerations during rehabilitation (ie, ≥ 60% of rehabilitation progression) was associated with a significantly lower reinjury risk at 2 months (relative risk [RR] range = 0.948-0.969; P < .01) and 6 months (RR range = 0.964-0.979; P < .05). Higher daily exposure to high-intensity accelerations once introduced was protective (RR = 0.861 (0.778-0.951)). There were no meaningful associations between total volume of HSR or sprinting and reinjury. Match running performance metrics did not differ between pre-injury and post-RTP matches (all P > .05). Changes in performance were not correlated with rehabilitation load characteristics. The timing of high-intensity running exposure during on-field rehabilitation appeared associated with a lower hamstring reinjury risk. Delaying the introduction of HSR, sprinting, and accelerations, followed by a structured and progressive build-up, was associated with lower risk of reinjury without compromising the subsequent match performance of elite male football players.

#13 The Effect of Three Work-Equivalent Whole-Body Vibration Protocols on Acute Neuromuscular Performance in Highly Trained Adolescent Soccer Players

Reference: J Musculoskelet Neuronal Interact. 2026 Sep 1;26(3):378-391. doi: 10.22540/JMNI-26-378.
Authors: Panagiotis Ampeliotis, Apostolos Z Skouras, Spyridon Methenitis, Charilaos Tsolakis, Georgios Papagiannis, Athanasios Triantafyllou, Panagiotis Koulouvaris
Summary: The study compared acute neuromuscular responses to three work-equivalent whole-body vibration (WBV) protocols in highly trained adolescent soccer players. Thirteen male soccer players (16.2 ± 0.3 years, BMI = 24.5 ± 1.5 kg/m2) completed a counterbalanced crossover study, performing on separate visits three WBV protocols: (P1) 1 x 3 min, (P2) 3 x 1 min, and (P3) 6 x 30 s. Knee extension maximal voluntary isometric contraction (MVIC) and vastus lateralis EMG (root-mean-square, RMS) were measured at baseline and at 2, 5, and 15 min post-WBV, followed by two CMJ trials at baseline (best retained) and one CMJ trial post-WBV. Time-to-peak torque (TPT), rate of torque development (RTD), and neuromuscular efficiency (NME) were also evaluated. No significant main effects of protocol or protocol-by-time interactions were observed across outcomes. Non-protocol effects were observed for EMGRMS normalized to baseline (%) (time, period, and carryover) and for carryover in RFD0-80 and CMJ power. Estimated effects were small, with wide confidence intervals. Among highly trained adolescent soccer players, a 3-min, work-equivalent WBV exposure administered as 1 x 3 min, 3 x 1 min, or 6 x 30 s did not produce clear protocol-dependent changes in knee extensor isometric performance, neuromuscular indices, or CMJ performance within 2-15 min post-intervention. Any effects appear minimal relative to inter-individual variability.

#14 Altered Spinopelvic and Hip Kinematics During Deep Squatting in Asymptomatic Adolescent Soccer Players With Cam Morphology: A Two-Year Prospective Study

Reference: J ISAKOS. 2026 Aug 31:101212. doi: 10.1016/j.jisako.2026.101212. Online ahead of print.
Authors: Dalia Al Otti, Filip Staes, Stijn Ghijselings, David F Alvarez-Anacona, Lennart Scheys
Summary: Cam morphology is prevalent in physically active adolescent males and is associated with the development of femoroacetabular impingement, yet the biomechanical factors associated with its development remain unclear. (1) To investigate longitudinal changes in squat kinematics and their association with Cam morphology development; and (2) to compare kinematics between asymptomatic athletes with and without Cam morphology. This prospective two-year study evaluated spinopelvic and hip kinematics in elite adolescent soccer players aged 12 to 16 years (baseline n=29; follow-up n=20), classified as having or not having Cam morphology based on skeletal maturity and an alpha angle >60° on hip radiographs. Three-dimensional motion capture was performed at both timepoints during standardized and unstandardized deep squats. Inverse kinematics of the trunk, lumbopelvic region, pelvis, and hip were analyzed. At baseline and follow-up, 58.5% of participants were classified as having Cam morphology (right hips=16; left hips=15). Statistical parametric mapping paired t-tests showed no statistically significant longitudinal changes in kinematic waveforms within either group. In the skeletally age-matched cross-sectional comparison, the Cam group demonstrated greater trunk flexion (17%-34%, p=0.032), lumbopelvic flexion (11%-30%, p=0.027), anterior pelvic tilt (35%-55%, p=0.012), and hip internal rotation (45%-55%, p=0.024) during the unstandardized squat compared with the No Cam group. Pelvic range of motion was also greater in the Cam group (28.0 ± 5.3° vs 20.5 ± 4.6°). No between-group differences were observed during the standardized squat. Asymptomatic adolescents with Cam morphology demonstrate distinct, task-dependent spinopelvic and hip kinematics during deep squatting, including greater pelvic motion. These patterns remain stable over time and are evident only under self-selected conditions, suggesting preferred movement strategies rather than fixed limitations in movement capacity.

#15 The Physical Match Running Demands of Canadian International Women’s Soccer

Reference: J Strength Cond Res. 2026 Aug 31. doi: 10.1519/JSC.0000000000005657. Online ahead of print.
Authors: Patrick Cormier, Bruna Mavignier, Daniel Geneau, Chloe Werle
Summary: This study examined position-specific match running demands across youth to senior Canadian female national team soccer players to establish normative data to inform physical performance preparation. External load match running data were collected via Catapult global navigation satellite sensors from 88 outfield players participating in the women’s national team pathway (under 17, under 20, and senior levels [WNTU17, WNTU20, and WNT, respectively]). Linear mixed models (level × position) were performed to investigate position-specific differences between international pathway levels. Concerning center backs, WNT players covered greater total distance and distance·min-1 than WNTU20 and greater distance·min-1 than WNTU17 players, and greater high deceleration efforts than WNTU17 and WNTU20 levels (effect size [ES] = 1.12-1.90, p ≤ 0.02). Regarding fullbacks, WNTU17 players performed fewer high accelerations and decelerations (total efforts and efforts·min-1) than WNT players (ES = 1.03-2.59, p ≤ 0.04). For forwards, WNTU17 players displayed lower maximum velocity expression (ES = 1.00, p = 0.04) than WNT. Concerning, midfielders, both WNTU17 and WNTU20 players performed lower distance·min-1, high-intensity running distance and m·min-1, high-speed running distance and m·min-1, and maximum velocity than WNT players. In addition, WNTU20 had lower sprint distance and m·min-1, high-intensity acceleration·min-1, and deceleration efforts (ES = 0.76-2.44, p ≤ 0.03) than WNT players. These results highlight key differences between national team pathway levels. Finally, these data highlight areas to target in the physical preparation of youth international players for the demands of top-level soccer.

#16 Flexible reconfiguration of variability structures between multiple solution manifolds in skilled soccer athletes‘ throw-ins

Reference: Hum Mov Sci. 2026 Aug 29:109:103530. doi: 10.1016/j.humov.2026.103530. Online ahead of print.
Authors: Rintaro Miyake, Hiroki Nakamoto, Sachi Ikudome, Ryo Watanabe, Munenori Murata
Summary: Skilled performers can produce highly consistent outcomes despite substantial variability within the motor control system. Previous studies have demonstrated that such consistency is achieved by structuring variability in execution variables so that it lies within the solution manifold. In this study, we extended this framework from conventional single-distance tasks with a fixed solution manifold to multiple-target conditions, and examined how athletes reconfigure variability in execution variables when the solution manifold changes shape across task demands. Ten male collegiate soccer athletes performed randomized, no-run-up throw-ins to targets at 10-90% of their individual maximum projection distance. Distance-specific solution manifolds were derived, and valid throws were classified as either the Task Tolerance strategy, which exploits regions of the solution manifold where variability in specific execution variables has little effect on the outcome, or a Covariant Structure strategy, which relies on compensatory covariation across execution variables. Participants adjusted projection distance reliably, and strategy use changed systematically with distance: the Covariant Structure strategy predominated at 20-40%, whereas the use of the Task Tolerance strategy increased sharply at 50-80% (Friedman p < .001). These results show that skilled throwers maintained broadly stable projection-distance variability even when task constraints changed and the underlying solution manifold took on different shapes. At the same time, the systematic shift in strategy use suggests distance-dependent reorganization of variability structures across distance-specific solution manifolds.

#17 Long-term changes in playing time, competitive level, and market value after ACL reconstruction in elite Spanish professional football players

Reference: Knee Surg Relat Res. 2026 Sep 4;38(1):46. doi: 10.1186/s43019-026-00346-0.
Authors: Verónica Montiel, Hugo Álvarez García, Natalia Alejandra Ramirez, Nerea Mateo, Andrés Valentí
Summary: The purpose of this study was to evaluate the epidemiology and longitudinal postinjury changes in playing time, competitive level, and market value in professional male football players from Spain’s First Division following anterior cruciate ligament reconstruction. This retrospective cohort study included 132 anterior cruciate ligament injuries in 115 professional football players identified between the 2010-2011 and 2023-2024 seasons using public databases (Transfermarkt and BeSoccer), with cross-validation against official medical reports or news sources. Return to play, league level, minutes played, and market value were tracked up to 5 years postinjury. Statistical analyses included chi-squared tests, repeated-measures analysis of variance (ANOVA), mixed-effects models with Dunnett-adjusted comparisons, Wilcoxon signed-rank testing, and exploratory multivariate regression analyses. The mean age at injury was 26.7 years. The return to play rate was 97.7%, with a mean return to play time of approximately 9.1 months. The first competitive appearance occurred at a median of 13.5 days after the first matchday squad inclusion. However, 35.2% of players dropped at least one competitive league level by the first postinjury season, increasing to 61.3% by the fifth season. Minutes played decreased by 46% in the first postinjury season (p < 0.001), with only partial recovery thereafter. Minutes per match played remained approximately 21 min below preinjury values during both the first and second postoperative seasons (both p < 0.001). Market value declined significantly across follow-up, reaching up to a 47.7% reduction by year 5, particularly among players aged 30 years or older. Longitudinal reductions in playing time, competitive level, and market value were observed following ACL injury in professional football players, despite high return to play (RTP) rates. Reduced minutes per match played further indicated persistent limitations in competitive utilization during the first two postoperative seasons.

#18 Athlete Monitoring in Norwegian Elite Women’s Football: An Exploratory Study of Current Practices and Perceptions

Reference: Int J Sports Physiol Perform. 2026 Sep 3:1-8. doi: 10.1123/ijspp.2025-0689. Online ahead of print.
Authors: Miriam Byberg, Sebastian S Sandgren, Espen Tønnessen, Håvard Myklebust
Summary: The increasing professionalization of women’s football has heightened the importance of appropriate load management. However, little is known about current athlete monitoring practices and stakeholder perceptions in women’s football. Therefore, this study aimed to examine monitoring practices and perceptions among (1) players and (2) coaching and performance staff to identify key facilitators and barriers to effective load management. All clubs from the Norwegian women’s Premier League were invited to complete a role-specific online survey on data collection, data analysis, implementation, and evaluation of current monitoring practice. Eight clubs participated, eliciting data from 6 head coaches, 8 practitioners, and 113 players. Five clubs (62.5%) reported systematic monitoring; all 5 included subjective measures, and 4 collected external loads, while 1 club measured counter movement jump test. Perceived individualization of training load (7-point Likert scale) yielded median scores of 5 and 6 for monitoring players and staff, respectively, compared with 4 and 2 for nonmonitoring players and staff. The most frequently reported challenges were „players not responding“ for data collection, „time constraints“ for data analysis, and „lack of equipment“ and „tactical considerations“ for decision on load adjustment. In this cohort, athlete monitoring was widely accepted but implemented heterogeneously and constrained by available resources. The findings generate the hypothesis that monitoring may increase perceived individualization of training, with good communication and visible use of data as potential facilitators. Future research should test this hypothesis in confirmatory studies and clarify the practical value of objective readiness measures for training-load decisions.

#19 Heat stress reduces high-speed running and sprint performances in highly trained young football players during official match play

Reference: Temperature (Austin). 2026 Aug 9;13(3):254-263. doi: 10.1080/23328940.2026.2710567. eCollection 2026.
Authors: Diêgo Augusto, João Brito, Fabrício V A Vasconcellos
Summary: This study aimed to analyze the running performance of highly trained young male football players during official matches played under different heat stress risk conditions. Young highly trained male football players (n = 37) from one club in Brazil were monitored during 50 official matches. Relative and absolute metrics were monitored, including total distance, low-to-moderate running, high-speed running and activities, sprinting distance, number of sprints, accelerations, and decelerations. Heat stress risk conditions were calculated using the wet-bulb globe temperature and were categorized as low, moderate, high. Linear mixed models were used to compare performance metrics under different heat stress risk conditions. Overall, relative and absolute performance metrics were reduced under high-risk conditions compared to low-risk: high-speed running distance and number of sprints and decelerations were reduced by 24%, 25%, and 19%, respectively (p < 0.05); in particular, high-speed running distance was markedly reduced in central defenders (-43%), fullbacks (-25%) and forwards (-19%) under high-risk conditions. Under moderate-risk conditions, compared to low-risk, high-speed running distance and sprinting were reduced (-16% and -26%, respectively; p < 0.01), with major differences in central defenders (-32%) and forwards (-16%). When high-risk conditions were compared with moderate-risk conditions, differences were observed in absolute metrics (p < 0.05): central defenders had reduced total distance and low-to-moderate running by 4-5%, whereas high-speed running distance was reduced in fullbacks (9%). These findings indicate that young highly trained football players reduce high-intensity running performance under heat stress, likely as a pacing strategy to cope with increased physiological strain during matches.

#20 Artificial intelligence in football talent identification: a systematic review

Reference: Front Sports Act Living. 2026 Aug 20:8:1770231. doi: 10.3389/fspor.2026.1770231. eCollection 2026.
Authors: Rui Zhou, Jorge Arede, Xinbi Zhang, Xiaocen Hao, Yingzhe Song, Zhimo Jiang, Bingnan Gong, Nuno Leite
Summary: The rapid development of artificial intelligence (AI) in sports has driven a shift in football talent identification from traditional experience-based judgment to data-driven decision-making. However, existing evidence on the application of AI in talent identification is dispersed, and a systematic synthesis of its application methods and effectiveness across different stages of the identification process is lacking. To systematically review the application of AI in football talent identification, compare sample characteristics, model types, data sources, and application contexts across different AI techniques, and summarize their advantages, limitations, and future directions. This systematic review followed PRISMA guidelines and was registered with PROSPERO. Searches were conducted in Web of Science, Scopus, SportDiscus, and PubMed to identify eligible studies, which were assessed for methodological quality. Information regarding sample characteristics, AI technique type, input features, model performance, and application context was extracted and synthesized. A total of 20 studies were included, covering youth and professional male players. Traditional machine learning models were the most frequently used, whereas deep learning and hybrid models were less common. AI demonstrated potential in three main areas: developmental potential identification, performance and role identification, and player value and recruitment decision-making. Although most studies adopted multidimensional feature sets, limitations remain regarding data quality, model interpretability, methodological rigor, and external validity. AI has shown substantial value in football talent identification, but current research is still transitioning from methodological exploration to systematic application. Future work should focus on developing more representative datasets, promoting cross-institutional data sharing, enhancing model transparency and interpretability, and validating AI models in real-world football contexts to ensure their safe, reliable, and effective application in talent identification practice.

#21 Physical profiling in elite professional men’s football: Academy, reserve and first team variations in fitness and performance

Reference: Open Access J Sports Med. 2026 Jul 4;17(1):2697533. doi: 10.1080/11791543.2026.2697533. eCollection 2026.
Authors: Thomas Carpels, Ole J Kemi
Summary: We profiled the physical fitness and training and match performance of elite academy (under-18 (U18, n = 23), reserve (RES, n = 15)), and first teams (FT, n = 25) to assess physical readiness for academy-FT progression. Further, we segregated players into player positions, ages, and current versus former academy players that had successfully progressed to FT. Aerobic capacity, anthropometry, and global positioning system- and heart rate-derived performance profiles in training and matches quantified external and internal loads. FT demonstrated 10% more body mass (p < 0.01) with similar adiposity, and ~10% higher aerobic capacity (p < 0.01) versus academy. In training, U18 covered more distances: 727 m (16%) total distance, 115 m (48%) high-speed, and 65 m (79%) sprint distance, and generated 0.63 m/s (8%) higher peak speeds versus FT (all p < 0.01), while FT displayed higher mean speeds: 8 m/min (11%) and 18 m/min (24%) versus U18 and RES (all p < 0.05). In terms of matches, U18 and RES covered more distance: total 539 m (5%) and 567 m (6%) and high-speed distance: 111 m (18%) and 121 m (20%), and displayed higher mean speeds: 13 m/min (11%) and 14 m/min (12%), versus FT (all p < 0.05). Thus, in this club, FT players demonstrated higher aerobic capacity, but not physical performance in training or matchplay. Academy players were not inferior, but displayed different performance behaviours.

#22 Associations between maturation assessment methods and growth-related injury occurrence in a German Bundesliga youth football academy

Reference: Front Sports Act Living. 2026 Sep 3;16(1):27686. doi: 10.1038/s41598-026-69051-y.
Authors: Felix Laukhardt, Tobias Engeroff, Sebastian Schneider, Christian Haser, Daniel Niederer, David Groneberg, Winfried Banzer
Summary: Peak height velocity (PHV) marks a sensitive period for adolescent athletes with increased injury risk. This prospective observational study explores how different maturation assessment methods are associated with injury occurrence, particularly growth-related injuries, during PHV in elite youth football players. Maturation of male U9-U16 players from the academy of a German Bundesliga club was assessed four times over one year using nine different methods (Mirwald, Moore, Fransen: ± 6/12 months, Khamis-Roche 85-96%/88-96%, ultrasonic BAUSport). Maturation was categorised into three periods relative to players‘ PHV (Pre-PHV, PHV, Post-PHV). For each assessment-quarter, injury occurrence was categorised as no injury, growth-related, non-contact, or contact. Injury occurrence across maturation periods was analysed in a Bayesian multinomial regression using data from 205 players (619 assessments). In this single-academy cohort, only the ultrasonic BAUSport-defined PHV period was associated with higher odds of growth-related injury, as results reveal lower odds versus no injury in Pre- and Post-PHV periods (OR = 0.33 and 0.17) relative to PHV. Most methods demonstrated higher odds of non-contact injury versus no injury with progressive maturation, while contact injuries did not differ between maturation periods. This preliminary association warrants evaluation in larger longitudinal cohorts with exposure data before informing monitoring or prevention practice.

#23 Graft type is not associated with revision ACL reconstruction in football players: a nationwide cohort analysis of subsequent ACL reconstructions

Reference: Br J Sports Med. 2026 Sep 3:bjsports-2026-111547. doi: 10.1136/bjsports-2026-111547. Online ahead of print.
Authors: Alexander Sandon, Magnus Forssblad
Summary: The purpose was to determine whether autograft type (hamstring, patellar or quadriceps tendon) is associated with risk of revision anterior cruciate ligament reconstruction (ACLR) or contralateral ACLR in football players. Nationwide cohort included all primary ACLRs performed in registered football players in Sweden between 2014 and 2023, identified by linkage of the Swedish Knee Ligament Registry and the Swedish Football Association. Return to competition (RTC) was defined as participation in at least one official match. Outcomes were revision ACLR (index knee) and contralateral ACLR. Sex stratified, cause specific Cox models adjusted for age and pre-injury level of play (Elite, Non-elite, Youth) were used, with hamstring tendon as graft reference. A total of 10 693 players were included, of whom 6238 (58%) RTC, mean age 22±7 years, mean follow up 5.2±2.9 years. Among RTC players, revision ACLR occurred in 232 women (10.8%) and in 349 (9.2%) men with no association between graft type and revision ACLR. Contralateral ACLR occurred in 263 women (12.2%) and 264 (6.9%) men. In women, quadriceps tendon was associated with a higher hazard of contralateral ACLR (HR 1.98, 95% CI 1.17 to 3.36). No graft-specific differences were seen in age-restricted sensitivity analyses or in the full cohort. Younger age and higher pre-injury level were consistently associated with greater subsequent ACLR risk. Graft choice was not independently associated with revision ACLR, including among young football players who RTC. An association between quadriceps tendon autograft and contralateral ACLR was observed among women. Across analyses, age and pre-injury level of play were the most consistent correlates of subsequent ACLR risk.

#24 Women’s football across codes: A scoping review of sports science, medicine, and female-health research themes

Reference: Sci Rep, 2026 Aug 14:S1440-2440(26)00525-6. doi: 10.1016/j.jsams.2026.08.204. Online ahead of print.
Authors: Charlotte Steele, Natalia Galan-Lopez, Matthew H Simpson, Lee Taylor, Bryna Catherine Rose Chrismas
Summary: The purpose was to map the quantity, scope, distribution, and research focus of female-specific research across all major football codes (soccer, futsal, Gaelic football, rugby union, sevens and league, Australian rules football, and American football), including sport science and medicine topics, performance-related themes, and female health domains assessed. Scoping review pre-registered with the Open Science Framework (https://osf.io/t2gqd/). Four databases were searched from inception to April 2025 using female health-related terms combined with football codes. Eligible sources included peer-reviewed research and female-specific National Governing Body (NGB) policy or strategy documents relating to competitive women’s football (Tiers 2-5), including recently retired athletes, referees, and/or support staff. Female-specific NGB policy and strategy documents were obtained from governing body websites and through direct correspondence with continental and UK home-nation governing bodies. Pilot title/abstract (κ = 0.58) and full-text (κ = 0.80) screening were completed independently by two reviewers to calculate inter-rater agreement, with full-text then proceeding with single-reviewer screening. Data including population, geography, age group, and themes were synthesised in Excel and visualised in RStudio using multilevel content evaluation. A total of 1425 publications (1385 studies; 40 policy/strategy documents) were included. Soccer dominated (80.6% of sport-category counts), followed by rugby union (4.3%) and Australian football (3.8%). Most involved Tier 3 (45.6%) and senior athletes (≥18 years; 48%). Underrepresented groups included youth (<18 years; 17%), veterans/masters athletes (>35 years; (1%), referees (1.9%), coaches (5.1%), and athletes with a disability (0.1%). Injury was the predominant theme (37.0%), whilst female health areas such as breast (0.5%), pelvic floor (0.5%), and menopause (0.1%) were scarce; menstrual cycle (MC) data were not reported in 69.0% of studies. The evidence base remains fragmented, injury-focused, soccer-centric, and neglectful of key female health domains. Broader, cross-code, female-centred research agendas and targeted investment are essential to advance equity, performance, and athlete welfare.

#25 Temporal trends in the relative age effect in five major European men’s football leagues, 2000-2025

Reference: Sci Med Footb. 2026 Sep 2:1-17. doi: 10.1080/24733938.2026.2728065. Online ahead of print.
Authors: Jeremy Torrent, Loric Rossier
Summary: The relative age effect (RAE) – the overrepresentation of athletes born early in the selection year – has been widely documented across youth and professional sport. However, less is known about how birth-quarter distributions among elite professional footballers have changed over extended historical periods. This descriptive-longitudinal study examined birth-quarter and birth-month distributions among male players in the Premier League, La Liga, Bundesliga, Serie A, and Ligue 1 across 25 seasons, from 2000-2001 to 2024-2025. The final dataset comprised 60,078 player-season records representing 14,173 unique players who accumulated at least 90 minutes of league playing time. Across the pooled sample, birth-quarter distributions differed significantly from a uniform expectation, with Q1-born players more frequently represented than Q4-born players (30.4% vs. 20.1%; χ2(3) = 1292.0, p < .001; Cramér’s V = 0.085). The same pattern was observed in the unique-player analysis (V = 0.085), suggesting that the pooled distribution was not driven solely by repeated seasonal observations of the same players. Season-level estimates increased during the earlier part of the observation window and subsequently stabilised, rather than showing continuous linear amplification across the full 25-season period. This temporal pattern varied substantially by league and requires interpretation in light of cohort replacement, player mobility, developmental-cutoff uncertainty, and changing league composition.

#26 Brain health in association football: perspectives of professional players

Reference: Front Sports Act Living. 2026 Aug 18:8:1876247. doi: 10.3389/fspor.2026.1876247. eCollection 2026.
Authors: J Batten, A J Pearce, N E Howarth, H Dawes, D H Daneshvar, C J Nowinski, A J White
Summary: Growing scientific and public concern regarding concussion and the potential long-term neurological consequences of playing professional football has increased attention on brain health within the sport. However, relatively little research has examined professional players‘ perspectives on concussion management and brain health risks. A cross-sectional, anonymous, online survey was distributed to members of the Professional Footballers‘ Association (PFA) in March 2023. The survey assessed concussion history, attitudes towards concussion management, support for temporary concussion substitutions, perceptions of heading-related risks, concerns about long-term neurological conditions, as well as engagement with concussion education. Responses from 600 current and former professional football players (97% male; 3% female) across multiple playing levels were analysed using descriptive statistics and non-parametric tests. A larger proportion of players reported having suspected a concussion during their career than reported receiving a formal diagnosis. Although many players indicated a preference to remain on the field following a suspected concussion, most believed that athletes should not be responsible for deciding whether to continue playing. Strong support was observed for the introduction of temporary concussion substitutions, particularly among retired players and those with longer playing careers. Many respondents also expressed concern regarding heading-related risks and the potential development of long-term neurological conditions. Players who had received concussion education demonstrated greater awareness of these risks. Discussion: Professional football players acknowledged important challenges in concussion recognition and management and broadly support policy measures aimed at improving player safety. The findings highlight potential gaps in concussion diagnosis and education within the professional game and suggest that players favour approaches that include thorough medical assessment and reduce pressures to continue playing following head injury. Incorporating athlete perspectives into policy development may help inform effective concussion management strategies and support efforts to protect the long-term brain health of professional footballers.

#27 Combined L-carnosine and L-tyrosine supplementation as an ergogenic strategy for physical and cognitive performance under fatigue in professional football players

Reference: Front Nutr. 2026 Aug 17:13:1868802. doi: 10.3389/fnut.2026.1868802. eCollection 2026.
Authors: Süleyman Bilgin, Eren Bozyılan, Yusuf Buzdağlı, Yeşim Karaç Öcal, Oğuz Gürkan, Sermet Toktaş, Hande İnan, İsmail Egil, Yunus Emre Yarayan
Summary: Background/ Football performance depends on the integration of high-intensity neuromuscular output with rapid decision-making and executive control. Although L-carnosine (L-CAR) and L-tyrosine (L-TYR) have independently demonstrated ergogenic and neurocognitive benefits, evidence regarding their combined effects on both physical and cognitive performance under post-exercise fatigue in football-specific contexts remains limited. This study aimed to investigate the acute effects of L-CAR, L-TYR, and their combined supplementation on physical and cognitive performance following high-intensity exercise in professional football players. Twenty-four male professionals completed a randomized, double-blind, placebo-controlled crossover trial involving four conditions (L-CAR, L-TYR, L-CAR+L-TYR, placebo). After supplementation, participants completed a Wingate-based fatigue protocol to assess anaerobic performance (peak power, mean power), followed by sprint tests (10-30 m; sprint time), an agility assessment (completion time), and football-specific passing accuracy tasks (execution time and accuracy). Executive function was evaluated using the Stroop test, including reaction time and error rates under neutral, congruent, and incongruent conditions. L-CAR significantly enhanced anaerobic power and agility, whereas L-TYR primarily improved cognitive performance. The combined condition produced the most pronounced effects, increasing peak power by ~17% and average power by ~16% versus placebo, reducing sprint and agility times by ~7-13%, and shortening incongruent Stroop reaction time by ~15%. Perceived exertion was lower with combined supplementation, while blood lactate concentrations did not differ significantly between conditions.

#28 Timing and Dose Matter: Late High-Speed Exposure and Higher High-Intensity Acceleration Volumes Reduce Hamstring Reinjury Risk in Elite Male Football (Soccer)

#29 Can LLMs reliably perform epidemiological extraction in elite football?

Reference: Proc Inst Mech Eng H. 2026 Aug 31:9544119261484234. doi: 10.1177/09544119261484234. Online ahead of print.
Authors: Julio López-Álvarez, Adrián Feria Madueño
Summary: Anterior cruciate ligament (ACL) injuries remain a critical burden in professional football, resulting in prolonged absence and high economic costs. While physical demands have increased, traditional epidemiological surveillance relies on manual data extraction, which is resource-intensive and subjective. Large Language Models (LLMs) offer a potential solution for automated screening, but their reliability in sports medicine remains largely unexplored. This study aimed to: (1) update the epidemiology of ACL injuries in the Spanish First Division (LaLiga) over six consecutive seasons (2019/2020-2024/2025) and (2) validate the accuracy of an AI-assisted screening approach using ChatGPT compared to manual data extraction. A retrospective observational study was conducted using publicly available sources. Manual screening by external investigators (gold standard) was compared against an AI-assisted workflow based on a structured prompt-engineering framework. Analyses focused on injury frequency, mechanism, return-to-play (RTP) time, recurrence rates, and AI case-detection sensitivity. A total of 56 ACL injuries were identified in 52 players. Findings revealed a predominance in defenders (41.1%), a high prevalence of non-contact mechanisms (67.9%), and a median RTP of 280 days. Notably, the match-to-training injury ratio was 1.8-1, a significantly narrower gap than historical records. The recurrence rate was 17.9%, with 70% of cases occurring in the contralateral knee. Methodologically, the AI model exhibited a learning curve: 44.4% sensitivity in the initial refinement season (2019/2020), which progressed to a sustained 100% sensitivity across the following five seasons (2020-2025). ACL injury incidence in LaLiga remains stable, but the narrowing match-to-training ratio suggests that modern training intensities are reaching competitive levels of biomechanical stress. LLMs, once optimized through prompt engineering, provide a highly reliable and scalable tool for near real-time epidemiological surveillance, representing a methodological milestone in sports medicine research.

#30 Reconceptualising game understanding in youth football: implications for applied research and practice

Reference: Sci Med Footb. 2026 Aug 30:1-7. doi: 10.1080/24733938.2026.2726164. Online ahead of print.
Authors: Alejandro Sanchez-Buitrago Morales, Howie J Carson, Alastair Pearson, Dave Collins
Summary: Game understanding is a fundamental part of performance development in youth football. Currently, however, the concept is inconsistently defined and operationalised across research and coaching contexts, leading to theoretical confusion, inconsistent research methods and practical problems when designing optimum applied learning environments. Accordingly, the aim of this article is to offer a conceptual framework through which game understanding in youth football can be interpreted moving forward. Specifically, we argue that game understanding is usefully explained through the integration of literature concerning contextual priors and transfer of understanding within a newly adopted framework by sport science researchers called predictive processing. This framework provides a nuanced explanation of how players anticipate, adjust and reorganise their decisions against constantly changing game situations and demands. Building on existing cognitive and metacognitive perspectives of game understanding, predictive processing offers a coherent framework for organising, interpreting and operationalising these ideas in youth football. We advocate that, instead of following fixed playing solutions or relying on spontaneous reactions to perceptions, football players‘ understanding informs their actions depending on their expectations, established reasoning and ability to adapt as game conditions and situations change. This view suggests that effectiveness depends on the combination of engagement/experience with information prior to the game through planning/preparation activities and that which becomes available during play itself.