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 The Influence of Individualization in External Load Control on Anaerobic Performance in a Women’s Soccer Team

Reference: Sports (Basel). 2026 Apr 1;14(4):138. doi: 10.3390/sports14040138.
Authors: Alexandre Galvão da Silva, Caroline Cavalcanti de Freitas, Alef Serrat Pinheiro et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13120117/pdf/sports-14-00138.pdf
Summary: Soccer is an intermittent sport that requires complex and well-adjusted physiological responses from athletes. The training load allows athletes to optimize physical adaptations and reduces the risk of musculoskeletal injuries. In women’s soccer, the implementation of load control and individualization strategies has shown promise for enhancing anaerobic performance and injury prevention. This study aimed to compare the performance levels of professional women’s soccer players before and after the implementation of relative external load (RELC) for training prescription. Twenty-seven female professional soccer athletes (mean age 29.4 ± 6.2 years) were evaluated. Metrics such as total distance, sprint distance, number of sprints, accelerations, and decelerations were collected using the GPS-based device Catapult One (Catapult). Athletes were assessed in two games, with 6 months‘ difference between matches: Game 1, without RELC implementation, and Game 2, with RELC. Significant differences were found between both periods. Sprint distance increased from 391 m to 450 m (+15%, d = 0.49, p ≤ 0.05), and sprint count increased from 14 to 17 (+21%, d = 0.35, p ≤ 0.05), showing improved performance related to increased physical output in the second half of the season. These findings suggest potential performance improvements associated with individualized load control over the course of the season.

2 Twelve Weeks of In-Season Strength Training at Moderate Intensities Improve Strength and Body Composition Without Increasing Muscle Damage or Inflammation in Elite Young Female Soccer Players

Reference: Sports (Basel). 2026 Apr 1;14(4):136. doi: 10.3390/sports14040136.
Authors: Mariem Bousselmi, Amira Ben Moussa Zouita, Manel Darragi et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13120612/pdf/sports-14-00136.pdf
Summary: Strength training (ST) is commonly implemented to enhance soccer-related fitness qualities such as sprinting, jumping, and changes-of-direction while also contributing to injury risk reduction. It is traditionally emphasized in the pre-season period. In-season ST may confer these benefits, but it can also induce muscle damage and inflammation. To examine the effects of a 12-week in-season ST program on maximal dynamic strength, muscle damage biomarkers, and inflammatory biomarkers, 24 elite young female soccer players (Tier 4 according to the McKay et al. classification) aged 14.9 ± 0.8 years and a maturity offset of +2.6 ± 1.1 years were randomly allocated to an ST group (STG, n = 12) or an active control group (CG, n = 12). Both groups followed the same soccer training program. However, in the STG, two weekly soccer sessions were replaced with ST. Overall training volume was comparable between groups. Maximal dynamic strength (1-RM tests for bench press, lat pull-down, and leg press), blood biomarkers of muscle damage (creatine phosphokinase [CPK], lactate dehydrogenase [LDH]), and inflammation (interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α]) were assessed before (T1) and after (T2) the interventions. Analyses showed significant increases for STG for the 1-RM bench press, the 1-RM lat pull-down, and the 1-RM leg press (p < 0.001). No significant interactions were detected for any blood marker of muscle damage (LDH and CPK) or inflammation (IL-6 and TNF-α) (all p > 0.05). Results support a 12-week in-season ST program improved maximal dynamic strength in elite young female soccer players without altering resting levels of muscle damage or inflammatory markers measured 48 h after training compared to regular soccer training. These findings suggest that ST can be safely implemented during the competitive season in young female soccer players without overreaching or overtraining.

3 Cross-sectional Evaluation of the Mechanical Axis and Other Angular Parameters of the Lower Limbs in Male Professional Soccer Players

Reference: Rev Bras Ortop (Sao Paulo). 2026 Apr 22;61(1):s00461818613. doi: 10.1055/s-0046-1818613. eCollection 2026 Feb.
Authors: Jean Klay Santos Machado, Eurineto Gomes do Nascimento, Erik Silva de Menezes
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13102537/pdf/10-1055-s-0046-1818613.pdf
Summary: The aim was to evaluate the mechanical axis and angular parameters of the lower limbs in professional soccer players, relating them to age, limb dominance, and field position. The present cross-sectional study included 102 male athletes from a Brazilian professional soccer team. Full-length radiographs in the orthostatic position were analyzed using the PeekMed (Peek Health, S.A.) software to measure the condylar efficiency (CE), the medial mechanical proximal tibial angle (mMPTA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical tibiofemoral angle (mTFA). The results were analyzed using descriptive statistics, analysis of variance (ANOVA), multivariate analysis of variance (MANOVA), Pearson’s/Spearman’s correlations, and multiple regression. The mean age of the participants was of 26.9 years. The valgus pattern was the most prevalent (68.6%), with bilateral valgus in 47.0% of the sample. A negative correlation was found between age and bilateral CE (ρ = -0.42 on the right side; and -0.39 on the left side; p < 0.05), and defenders and left-footed players presented greater condylar asymmetry (ΔCE). The MANOVA indicated a significant association between field position and angular parameters ( p = 0.0016), with no global effect of dominance ( p = 0.243). Midfielders and fullbacks showed a higher prevalence of valgus (of up to 80%), while defenders and goalkeepers commonly presented with neutral alignment. There were significant bilateral differences in CE, mMPTA, and mTFA. Age and field position influenced lower-limb alignment in professional soccer players, with more pronounced asymmetries in defenders and left-footed athletes. Individualized monitoring of the mechanical axis may help prevent injuries and optimize performance.

4 Risk of Cognitive Decline in Professional Soccer Players after Repetitive Subconcussive Impacts: A Systematic Review and Meta-analysis

Reference: Neurol Med Chir (Tokyo). 2026 Apr 24. doi: 10.2176/jns-nmc.2025-0451. Online ahead of print.
Author: Tomasz Tykocki
Download link: https://www.jstage.jst.go.jp/article/nmc/advpub/0/advpub_2025-0451/_pdf/-char/en
Summary: Repetitive soccer heading has been implicated as a potential source of cumulative subconcussive brain injury, yet the magnitude and consistency of its cognitive effects remain incompletely defined. We conducted a systematic review and meta-analysis to quantify global and domain-specific cognitive outcomes associated with repetitive heading exposure. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, PubMed/MEDLINE, Scopus, and Web of Science were searched through December 2025. Of 2,846 identified records, 46 studies met the inclusion criteria, and 28 provided standardized cognitive data suitable for quantitative synthesis. Effect sizes (Hedges g, Fisher z) were transformed into log odds ratios and pooled using DerSimonian-Laird random-effects models. Heterogeneity was assessed using Q, I2, and H2 statistics, and publication bias was evaluated with funnel plots, Egger regression, and trim-and-fill procedures, alongside leave-one-out influence analyses. Across 28 independent author-level datasets, repetitive heading was associated with significantly increased odds of global cognitive underperformance (odds ratio 1.67; 95% confidence interval 1.61-1.72), with moderate heterogeneity (I2 ≈ 34%). Trim-and-fill adjustment yielded a modestly attenuated but still significant estimate (odds ratio 1.49). Domain-level analyses demonstrated consistent impairments across visuospatial ability (odds ratio 1.49), verbal memory (odds ratio 1.62), attention (odds ratio 1.71), processing speed (odds ratio 1.64), executive function (odds ratio 1.86), and composite cognition (odds ratio 1.58). Confidence intervals were narrow, once, and the effect directionality was uniform across domains. These findings indicate that repetitive soccer heading is associated with robust, reproducible cognitive deficits across multiple cognitive systems, supporting cumulative subconcussive exposure as an independent risk factor for measurable cognitive decline.

5 Athletic ability discrepancy, risk-taking, and recovery quality as predictors of match-related injuries in adolescent soccer players

Reference: Sci Rep. 2026 Apr 25. doi: 10.1038/s41598-026-49793-5. Online ahead of print.
Authors: Aynollah Naderi, Vahid Reza Kohe, Luis Calmeiro
Download link: https://www.nature.com/articles/s41598-026-49793-5_reference.pdf
Summary: This prospective cohort study aimed to identify predictors of match-related injuries in 40 male adolescent soccer players (mean age 15.25±0.87 years) across 20 regional league matches during the 2023–2024 season. Prior to each match, players completed validated assessments of mental fatigue, recovery quality, perceived match load, perceived injury risk, risk-taking behaviors, and athletic ability, with self- and coach ratings calculated to determine the Athletic Ability Discrepancy Score. All musculoskeletal injuries, regardless of time loss or medical attention, were documented by physiotherapists based on Fuller and Ekstrand’s criteria. Results revealed that 47.5% of players sustained at least one injury (26 injuries total), with a rate of 24.9 injuries per 1,000 match hours. Contusions (46.2%) and sprains (30.8%) were most common. Multivariate GEE analysis identified three significant injury predictors: a higher Athletic Ability Discrepancy Score (OR=1.48, 95% CI: 1.10–1.99, p=0.01), lower recovery quality (OR=0.75, 95% CI: 0.57–0.99, p=0.04), and greater risk-taking behaviors (OR=1.54, 95% CI: 1.03–2.32, p=0.04). Mental fatigue, match load, and perceived injury risk were not significant predictors (P>0.05). These findings highlight the need for psychological screening, particularly for other self-rating discrepancies, and interventions promoting realistic self-assessment, behavioural regulation, and structured recovery in youth injury prevention.

6 Relationship between knee isokinetic muscle strength and countermovement jump performance in elite male football players

Reference: BMC Sports Sci Med Rehabil. 2026 May 1. doi: 10.1186/s13102-026-01722-9. Online ahead of print.
Authors: Denis Čaušević, Cristina Ioana Alexe, Ensar Abazović, Elena Adelina Panaet, Nedim Čović, Dan Iulian Alexe
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01722-9_reference.pdf
Summary: Countermovement jump (CMJ) performance is widely used to assess explosive lower-limb function in football players. Although knee isokinetic strength is frequently measured in elite sport environments, the extent to which it relates to CMJ performance remains unclear, particularly when CMJ is performed with free arm movement. Therefore, the aim of this study was to examine the relationship between knee isokinetic muscle strength characteristics and CMJ performance in elite male football players. Twenty-four elite male football players (age 23.83 ± 5.98 years) participated in this cross-sectional study. CMJ height was assessed using an optical measurement system (Optojump Next). Concentric knee extensor and flexor peak torque was measured using an isokinetic dynamometer at angular velocities of 60°/s and 180°/s and expressed as peak torque/body weight% (PT/BW,%). Pearson correlation and linear regression analyses were used to examine associations between isokinetic strength variables and CMJ performance. Bilateral differences, hamstring-to-quadriceps (H/Q) ratios, and inter-limb asymmetries were also analyzed. Significant positive correlations were observed between CMJ height and knee extensor peak torque expressed as PT/BW (%) at both angular velocities. Stronger relationships were found at 180°/s (r = 0.558-0.642, p ≤ 0.005) compared with 60°/s (r = 0.483-0.500, p < 0.05). Regression analyses showed that knee extensor strength at 180°/s explained up to 41.2% of the variance in CMJ height. Hamstring strength demonstrated weaker and less consistent associations with CMJ performance, while H/Q ratios and inter-limb asymmetries were not significantly related to jump height. Quadriceps isokinetic strength expressed as PT/BW (%) was significantly associated with CMJ performance in elite male football players, with stronger relationships observed at higher angular velocity. These findings suggest that knee extensor strength assessed at higher angular velocity is meaningfully associated with explosive lower-limb performance and may provide useful complementary information within routine neuromuscular monitoring in professional football.

7 Insurance Type Affects Access to Care for Young Football Athletes with Hip Labrum Tears

Reference: South Med J. 2026 May 4;119(5):269-273. doi: 10.14423/SMJ.0000000000001964.
Authors: Nathaniel Buchanan, Jackson Byrd, Clay A Rahaman et al.
Summary: Patients with Medicaid compared with private insurance have increased difficulty gaining access to orthopedic care. How insurance status affects access to care for young athletes (football; from here, all „young athletes“ are football players) with hip labrum tears has yet to be assessed. The purpose of this study was to determine whether there is a difference in insurance acceptance rates for Medicaid versus Blue Cross Blue Shield (BCBS) for young athletes with a hip labral tear. Fifty orthopedic clinics across 10 states were contacted using a standardized script. Each clinic was called twice: once as a young athlete with BCBS and once with a young athlete with Medicaid, requesting an appointment for a hip labral tear. The primary outcome was appointment success. Secondary outcomes included barriers to scheduling and wait times. Statistical analysis was performed using chi-squared and Mann-Whitney U tests. All clinics accepted BCBS insurance, whereas only 16 (32%) accepted Medicaid (P<0.0001). Young athletes with BCBS successfully scheduled an appointment 100% of the time compared with only 24% for young athletes with Medicaid (P<0.0001). Of the 34 clinics that did not accept Medicaid, 22 (65%) cited not accepting the insurance, and 11 (32%) required a referral. Among clinics that accepted both insurance types, there was no significant difference in median wait time (13 vs 14 days, P=0.44). For young athletes with hip labrum tears, it is more difficult to schedule appointments with Medicaid insurance compared with BCBS insurance. The main barrier to care with Medicaid for young athletes is requiring a primary care physician referral.

8 ICRS-FIFA-Aspetar consensus on the management of knee cartilage injuries in football players: part 2-appropriateness of specific surgical procedures to address articular cartilage lesions in different clinical scenarios using the RAND/UCLA appropriateness method

Reference: Br J Sports Med. 2026 Apr 30:bjsports-2025-110676. doi: 10.1136/bjsports-2025-110676. Online ahead of print.
Authors: Emmanuel Papakostas, Elizaveta Kon, Luca Andriolo et al.
Summary: Knee articular cartilage lesions are frequent in football players, but evidence for the most suitable surgical treatments is lacking. The aim of this International Cartilage Regeneration & Joint Preservation Society, Fédération Internationale de Football Association and Aspetar (ICRS-FIFA-Aspetar) consensus was to develop expert-based, patient-specific practical recommendations on the appropriateness of surgical treatments for symptomatic knee articular cartilage lesions in competitive football players. The RAND/UCLA Appropriateness Method was used by 17 voting experts to provide recommendations on the suitability of six different surgical procedures (debridement, debridement+orthobiologics, bone marrow stimulation procedures, osteochondral autograft transplantation, allografts, and regenerative procedures) depending on four key clinical considerations: lesion location, defect size, bone involvement, and patient preference towards higher priority for a quick return to play or long-term results. These resulted in 96 scenarios (16 clinical scenarios for six surgical procedures). Altogether, in 94% of clinical scenarios, at least one surgical procedure was considered appropriate. Patient preference had the highest influence on the results. Debridement plus orthobiologics was most often considered appropriate in patients preferring a quick return to play, while regenerative techniques were more often considered appropriate with patients prioritising long-term results. Osteochondral autograft transplantation and allografts were considered appropriate only in selected scenarios, whereas bone marrow stimulation procedures were considered inappropriate or uncertain. The recommendations established by this ICRS-FIFA-Aspetar consensus on the appropriateness of different surgical procedures to treat symptomatic articular cartilage lesions in competitive football players should be used as broad guidelines, but the preferred treatment should be player-specific.

9 Beyond Return-To-Sport: Mapping ACL Injury History in Currently Active Female Football Players From Youth to Senior Elite Level

Reference: Transl Sports Med. 2026 Apr 28:2026:4174828. doi: 10.1155/tsm2/4174828. eCollection 2026.
Authors: Mette K Zebis, Mikkel B Clausen, Connie Linnebjerg, Mette Hansen, Jesper Bencke, Lars L Andersen, Per Hölmich, Kristian Thorborg
Download link: https://onlinelibrary.wiley.com/doi/epdf/10.1155/tsm2/4174828
Summary: This study determines the prevalence of ACL injury history among currently active female football players across age groups and playing levels and examines the association between ACL injury history and activity-related knee pain. A total of 1026 active Danish female youth- and senior-league football players were invited to an online questionnaire (response rate: 751 [73%]) on (1) ACL injury history and (2) present knee pain during physical activity. Prevalence was calculated separately according to age (youth vs senior) and playing level (non-elite vs elite). Logistic regression analyses investigated factors associated with the prevalence of ACL injury history and activity-related knee pain, respectively. The prevalence of ACL injury history was 5.0% (95% confidence interval [CI] 3.3%-7.4%) in youth football and 14.8% (95% CI 10.6%-19.8%) in senior football. The prevalence of activity-related knee pain was comparable between youth (24.6%, 95% CI 20.8%-28.7%) and senior football players (26.0%, 95% CI 20.7%-31.9%). Comparable prevalence of ACL injury history and knee pain was reported at elite and non-elite level. ACL injury history was strongly associated with activity-related knee pain (OR = 5.4-8.7, p < 0.0001). Playing with a previous ACL injury is common in active female football players, particularly at senior levels (nearly 1 in 6 elite players). The strong association between ACL injury history and activity-related knee pain underscores the long-term negative consequences. This study highlights the need for secondary and tertiary prevention strategies in female football.

10 Sudden cardiac arrest preparedness in African football: evidence from Cameroon and implications for global sport

Reference: Br J Sports Med. 2026 Apr 29:bjsports-2025-110869. doi: 10.1136/bjsports-2025-110869. Online ahead of print.
Authors: Leonard Tanko Tankeng, Gilbert Mua Akwa, Adaeze Uju Liz Sandra Ossaih et al.
Download link: https://bjsm.bmj.com/content/bjsports/early/2026/04/29/bjsports-2025-110869.full.pdf
Summary: Sudden cardiac arrest (SCA) remains the leading cause of sport-related death worldwide, yet survival outcomes in Africa are critically poor. We conducted a formative assessment of the knowledge, attitudes and practices of professional football stakeholders in Cameroon as a model for identifying system-level gaps in SCA preparedness in low-resource sport settings. We conducted a cross-sectional survey during the 2024/2025 season across five pre-competition medical centres in Cameroon. Eligible participants were players, referees, coaches and physiotherapists from Elite 1, Elite 2 and the Female Super League who had two or more seasons of professional experience. A validated questionnaire, adapted from international guidelines, was used to assess sociodemographic data, knowledge, attitudes and practices. Data were analysed descriptively with subgroup comparisons using SPSS V.20. A total of 745 participants were enrolled: 536 players, 90 referees, 84 coaches and 35 physiotherapists. Most (66.4%) demonstrated poor knowledge of SCA, only 12% reported confidence in cardiopulmonary resuscitation (CPR) or automated external defibrillator (AED) use and referees showed the lowest preparedness scores despite their critical first-responder role. While one-third expressed positive attitudes, self-reported barriers to providing CPR included fear of harm (66.3%) and legal concerns (78.3%). Only 33.4% reported good practices, with significant gaps in AED access, CPR training and emergency action plan awareness. This assessment identified critical gaps in SCA preparedness in Cameroonian football, exposing gaps that likely extend across Africa and similar environments. Compulsory CPR/AED training, AED availability and enforceable emergency action plans are urgently needed to align African football with international best practice and strengthen the survival chain.

11 Evaluating player relevance in football teams through cooperative game theory

Reference: Sci Rep. 2026 Apr 28. doi: 10.1038/s41598-026-50405-5. Online ahead of print.
Authors: Eduardo Zúñiga-Leyton, Luis Cornejo, Verónica Díaz, Fernando Feres, Renny Márquez
Download link: https://www.nature.com/articles/s41598-026-50405-5_reference.pdf
Summary: This paper develops a cooperative game-theoretic methodology to measure a footballer’s relevance to team play by combining structural information-the network of completed passes-with individual performance data. This integration is the core of our methodological contribution. Using this information and the Shapley value concept from game theory, we propose four relevance measures (based on the Shapley value) that quantify each player’s relevance in a given match. We then apply the methodology to Argentina’s seven matches at the 2022 FIFA World Cup in Qatar. Our results illustrate how the method can reveal players whose structural importance may not be captured by standard performance metrics (such as individual ratings) or standard centrality measures, providing complementary insights. Furthermore, the methodology is flexible, allowing analysts to tailor it to emphasize alternative tactical hypotheses and making it adaptable for team self-analysis, opponent preparation, and scouting.

12 Seasonal Analysis of Match External Load in Hungarian Second-Division Professional Football Across Three Competitive Seasons Using GPS-Derived Match-Average Data

Reference: Sports (Basel). 2026 Apr 15;14(4):155. doi: 10.3390/sports14040155.
Authors: Richárd Bauer, Bálint István Ruppert, Bálint Kilvinger, Árpád Petrov, István Barthalos, László Suszter, Ferenc Ihász, Zoltán Alföldi
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13119771/pdf/sports-14-00155.pdf
Summary: The aim of this study was to describe seasonal trends in match-average External Load (EL) variables across three (2022/23, 2023/24, 2024/25) consecutive competitive seasons in a Hungarian professional second-division soccer team (Gyirmót FC Győr), using the Catapult Vector S7 Global Navigation Satellite System (GNSS). Specifically, Average Distance (AD; m), Average Player LoadTM (PL; AU), and Acceleration-Deceleration Efforts (>2 m·s-2) (ADE) were examined. The study aimed to provide descriptive reference values and characterize seasonal variation in match EL demands within a professional second-division context. A descriptive seasonal comparison was conducted based exclusively on aggregated match average EL values. The unit of analysis was the match, with each match contributing one aggregated value per variable derived from players who completed the full match. A total of 94 matches were included (2022/23: N = 38; 2023/24: N = 29; 2024/25: N = 27); matches with red cards were excluded. EL data were collected using a 10 Hz Catapult Vector S7 GNSS. The median AD decreased continuously from the 2022/23 season (10.210 m) to the 2024/25 season (9.795 m). The median PL decreased from 1002 (2022/23 and 2023/24) to 846 in the 2024/25 season. The median ADE decreased from 220.8 (2022/23) to 199.0 (2024/25). Lower values were observed across match EL variables, with the most pronounced reduction in PL. These findings provide descriptive reference values and may support the interpretation of seasonal variation in match EL demands in professional second-division soccer.

13 Concussion Symptoms Scale and the Association with Temperature, Equipment, and Play Duration in Non-Concussed Football Players

Reference: Sports (Basel). 2026 Mar 31;14(4):133. doi: 10.3390/sports14040133.
Authors: Rachel Matthews, Ankur Verma, Derek Calvert et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13119781/pdf/sports-14-00133.pdf
Summary: Symptom scales are routinely used in sport during concussion screening and return-to-play. Limited research has explored the presence of concussion symptoms in the absence of a diagnosed concussion. This study analyzed concussion symptom scores in concussed vs. non-concussed football players after football activities and evaluated the effect of field of play variables. NCAA Division I football players with (n = 9) and without (n = 30) diagnosed concussion completed concussion symptom scales (C3 Logix) following practice for 1 week. Wet bulb globe temperature (WBGT), play duration, equipment, and location (inside/outside) were recorded. Mixed models analyzed the effect of day, WBGT, equipment, location, and play duration on concussion-like symptoms in non-concussed players and determined the time course of symptom relief in concussed players. Fatigue or low energy (27.6%), neck pain (16.8%), feeling slowed down (14.8%), and headache (12.8%) were most reported. In non-concussed players, total symptoms scores were higher early in the week (Monday/Tuesday) and decreased throughout the week (p < 0.01). No effect of play duration (p = 0.49), WBGT (p = 0.12), equipment (p = 0.40), or location (p = 0.83) was found. Symptom scores were greater in the concussed vs. non-concussed groups on days 1-3. Football players report concussion-like symptoms in the absence of a concussion diagnosis, particularly following the first few practices after a game.

14 Dynamic Field Assessment of Hip Adductor Function Using a Smartphone-Based Copenhagen Test: Reliability and Concurrent Associations with Isometric Strength in Amateur Football Players

Reference: Sports (Basel). 2026 Mar 24;14(4):125. doi: 10.3390/sports14040125.
Authors: Aaron Miralles-Iborra, Tomas Urban, Javier De Los Ríos-Calonge et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13120274/pdf/sports-14-00125.pdf
Summary: Assessing hip adductor muscle strength is important for identifying weakness or side-to-side imbalances associated with groin injury risk. Although the Copenhagen adductor exercise is widely used to evaluate adductor function, the quantification of strength-related outcomes using inertial sensors integrated in smartphones during this task has not been systematically examined. This study aimed to evaluate the reliability of a smartphone-based Copenhagen adductor field test and its associations with established isometric hip adductor strength assessments. Twenty amateur male football players (21.1 ± 3.2 years) completed two laboratory sessions separated by one week. The reliability of the smartphone-based Copenhagen test was assessed for endurance-related outcome (repetition count) and strength-related outcomes (mean repetition time and peak velocity) using intraclass correlation coefficients (ICC), standard error of measurement (SEM), and minimum detectable change (MDC). Participants also performed unilateral and bilateral isometric hip adductor tests using load cells to obtain isometric peak force (IPF) and rate of force development at 150 ms (RFD150). Associations were examined using Pearson correlation coefficients. The smartphone-based Copenhagen test showed ICC point estimates ranging from 0.63 to 0.83, although several 95% confidence intervals were relatively wide (ICC = 0.63-0.83; SEM = 6.7-18.5%). Endurance-related outcomes were not significantly associated with IPF or RFD150. In contrast, peak velocity showed low-to-moderate correlations with RFD150 (r = 0.48-0.63) and moderate correlations with IPF (r = 0.50-0.64; p < 0.05). These findings suggest that the peak velocity obtained during the Copenhagen adductor test may provide a practical field-based complement to conventional isometric assessments. However, given the moderate strength of the observed associations and the measurement error of peak velocity, these outcomes should be interpreted with caution and warrant further investigation.

15 From mind to match: the impact of psychological skills intervention programs on football players‘ mental toughness, decision-making, and tactical skills: a randomized controlled group study

Reference: Front Psychol. 2026 Apr 10:17:1828902. doi: 10.3389/fpsyg.2026.1828902. eCollection 2026.
Authors: İbrahim Dalbudak, Mehmet Behzat Turan, Oğulcan Usuflu et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13106408/pdf/fpsyg-17-1828902.pdf
Summary: Football is characterized by rapidly changing and highly demanding competitive conditions in which players are frequently exposed to substantial psychological pressure. Athletes‘ psychological responses to these pressures can directly influence critical performance-related factors such as decision-making, tactical execution, and overall game performance. In modern football, physical and technical abilities alone are often insufficient for achieving high-level performance; psychological competencies have become increasingly important determinants of success. Consequently, the development and implementation of structured psychological training approaches have gained considerable attention in sports science research. In this context, Psychological Skills Intervention (PSI) programs are considered promising strategies for enhancing athletes‘ psychological capacities and optimizing their performance in competitive environments. This study aims to investigate the effects of Psychological Skills Intervention (PSI) programs on football players‘ mental toughness, decision-making abilities, and tactical skills. The study sample consisted of football players from the youth academies of professional football clubs competing in the Turkish Football Federation (TFF) Development Leagues during the 2025-2026 season. A total of 55 football players voluntarily participated in the study and were divided into a control group (n = 28) and an experimental group (n = 27). The control group followed the standard training program implemented by their teams. In contrast, the experimental group participated in an eight-week Psychological Skills Intervention (PSI) program in addition to the standard training program. The variables included in the study were assessed at three different time points. The data from the study were analyzed using SPSS 26. Repeated Measures ANOVA with Bonferroni post hoc comparisons was conducted to examine within-group changes over time, while Independent Samples t-tests were used to evaluate differences between the control and experimental groups. Although improvements were observed in the mental toughness, decision-making, and tactical skills of U-19 footballers in the control group, statistically significant improvements were observed in the experimental group who participated in the PSI program. The findings suggest that integrating Psychological Skills Intervention (PSI) programs as a systematic, integral component of training for footballers competing in development leagues can significantly enhance players‘ individual performance and career development as they progress through the competitive pathway. Furthermore, such programs may play a critical role in developing elite-level footballers capable of contributing to the long-term and sustainable success of national football.

16 Effect of conventional warm-up versus stretching warm-up on physical performance in children soccer players: a randomized crossover trial

Reference: Front Physiol. 2026 Apr 22:17:1827385. doi: 10.3389/fphys.2026.1827385. eCollection 2026.
Authors: Jordan Hernandez-Martínez, Izham Cid-Calfucura, Joaquín Perez-Carcamo, Sebastián Canales-Canales, Eduardo Guzmán-Muñoz, Edgar Vásquez-Carrasco, Tomás Herrera-Valenzuela, Pablo Valdés-Badilla
Download link: https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2026.1827385/full
Summary: The aim was to evaluate the effects of the conventional warm-up (CC) compared to warm-ups that included static (SSC), dynamic (DSC), or ballistic (BSC) stretching on jump performance (CMJ, SJ, DJ), curve sprint speed, agility (ICODT), and ball kicking speed in male children soccer players. Eighteen male soccer players (mean age: 11.2 ± 2.4 years) experiencing four warm-up conditions: CC, SSC, DSC, and BSC. They were performed in a random sequence with a 72-hour recovery period in between. After each warm-up, physical performance was measured through the CMJ, SJ, DJ, curved sprint speed, ICODT, and ball kicking speed. Significant improvements were observed in the ICODT for SSC and DSC compared to CC (p < 0.001). In the CC and SSC conditions, better performance was obtained in curved sprint speed (p = 0.003) compared to DSC, in ball kicking speed with the dominant foot for all stretching conditions (SSC, DSC, and BSC) compared to CC (p < 0.001), and in ball kicking speed with the non-dominant foot for DSC and BSC compared to CC (p = 0.002). In conclusion, that warm-ups incorporating SSC and DSC enhance ICODT in children’s soccer players, while all stretching modalities improve ball kicking speed with the dominant foot compared to a CC. For curve sprint speed, the CC and SSC were more effective than DSC.

17 AI-Powered Monitoring of the Acute: Chronic Workload Ratio: Interpretable Injury Risk Prediction in Soccer Players

Reference: Sports Health. 2026 May 7:19417381261435557. doi: 10.1177/19417381261435557. Online ahead of print.
Authors: Deyu Meng, Meiqi Wei, Shichun He, Zongnan Lv, Guang Yang, Ziheng Wang
Summary: This study proposes a model for monitoring the acute:chronic workload ratio (ACWR). Historical training data are able to predict a soccer player’s future ACWR. We propose a timeseries model built upon a Transformer-based foundation model -Tabular Probabilistic Forecasting Network for Time Series—based on historical training data from soccer players, incorporating sensor data (such as Global Positioning System or accelerometers) and athletes’ subjective feedback. We leveraged prompt engineering and large language models to enhance the model’s predictive capability, extracting previous knowledge-based artificial features from the DeepSeek model. Our model achieved an average mean absolute error of 0.119, an average mean squared error of 0.029, an average root mean square error of 0.149, and an average R2 of 0.564 in ACWR prediction. In addition, in ACWR_RISK prediction, the model achieved an accuracy of 87.12%, precision of 85.91%, recall of 87.12%, and an F1 score of 85.27%. Extensive experimental results demonstrate that the model predicts the future injury risk of soccer players effectively, helping players regulate workload fluctuations and maintain their training state and injury risk within an optimal zone. The proposed model provides a practical tool for monitoring and predicting athletes’ workload dynamics, enabling early identification of elevated injury risk associated with abnormal ACWR fluctuations.

18 Sleep duration, timing, and regularity during school, training, and holiday periods in male adolescent soccer players

Reference: Sci Rep. 2026 May 7. doi: 10.1038/s41598-026-51685-7. Online ahead of print.
Authors: João Barreira, Elisa A Marques, João Brito, Fábio Y Nakamura, Ricardo Pimenta, Pedro Figueiredo
Download link: https://www.nature.com/articles/s41598-026-51685-7_reference.pdf
Summary: Sleep is essential for adequate physical recovery and performance, but adolescent athletes face unique challenges that can disrupt sleep. Thus, this observational study aimed to monitor sleep in highly trained male adolescent soccer players between three distinct periods: (1) concurrent school and training; (2) morning training only (during the school winter break); and (3) a full holiday period (with no school or training) and assess the influence of morning alarm use on the differences between periods. Thirty-four male academy soccer players (16.6 ± 0.9 years) were monitored for five weeks using wrist-worn actigraphy and daily sleep diaries. Sleep outcomes included time in bed (TIB), total sleep time (TST), sleep timing, and the Sleep Regularity Index (SRI). Linear mixed-effects models were used to compare sleep variables across periods and to test interactions with morning alarm use. Mean sleep duration across the monitoring period was 06:47 ± 01:10 h, with none of the participants achieving the recommended minimum of 8 h of daily sleep. TIB and TST were slightly lower during the training-only period compared with the other periods (- 18 to – 31 min; trivial to small effects). Holidays were characterized by substantially later bedtimes (~ 1.5-2 h; moderate effects) and wake-up times (~ 2 h; moderate effects), without a meaningful increase in sleep duration (3 to 21 min; trivial effects). Marked differences in SRI were observed between periods (moderate to large effects), with higher SRI during structured periods and the lowest regularity during holidays (moderate to large effects). Not using an alarm resulted in longer TIB (+ 87 min; large effects) and TST (+ 66 min; moderate to large effects), particularly during holidays. The main results highlight that highly trained male adolescent soccer players had later sleep timing during holidays, which did not necessarily promote longer sleep; instead, it was associated with reduced sleep regularity. Moreover, morning alarm use negatively influenced sleep opportunity.

19 The Most Demanding Match Periods in Youth Male Soccer: Analysis by Age Groups and Playing Position

Reference: Int J Sports Physiol Perform. 2026 May 6:1-8. doi: 10.1123/ijspp.2025-0594. Online ahead of print.
Authors: Ricardo Pimenta, Juliano Pires, José Afonso, João L Mesquita, Fábio Y Nakamura
Summary: The aim was to quantify and compare most demanding periods (MDPs) of match play in soccer for total distance, high-speed running distance, and sprint distance across 1-, 3-, and 5-minute periods, examining both positional differences and age groups (under 17, under 19, and under 23) in youth male soccer players. Sixty-eight outfield players from the same professional academy (under 17: n = 24, under 19: n = 23, and under 23: n = 21) competing in top national divisions were monitored over 50 official matches using 10-Hz global navigation satellite system units (Catapult Vector S7). MDPs were identified using the rolling average method for each period. Linear mixed models compared MDPs among positions and age groups, with Bonferroni-adjusted post hoc tests and effect sizes (Cohen’s d). No differences were observed between age groups for any metric or period length (P > .05). However, positional differences were found. Center backs consistently exhibited the lowest values across all metrics (P < .05; d = 1.18-2.72), while midfielders showed similar sprint distance values to center backs. Strikers and wingers presented the highest sprint distance MDPs, whereas midfielders and strikers recorded the highest total distance MDPs. Shorter time windows produced higher relative values (in meters per minute) across all metrics. From under 17 onward, highly trained male youth players displayed comparable external load demands during the MDPs of match play, irrespective of age group. Conversely, MDPs were strongly position-dependent, reflecting distinct tactical and physical demands. These findings reinforce the importance of position-specific training while ensuring all players are prepared to cope with atypical high-intensity demands during match play.

20 Modified Maddocks Questions Tool in Spanish: evaluating comprehension among child soccer players aged 4-8

Reference: Front Sports Act Living. 2026 Apr 21:8:1793910. doi: 10.3389/fspor.2026.1793910. eCollection 2026.
Authors: Federico Baltar, Camila Blanco, Ailin Collazo et al.
Download link: https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2026.1793910/full
Summary: The Modified Maddocks Questions Tool (MMQT) is part of the Concussion Recognition Protocol used for sideline assessment of suspected concussion. Although widely used in English-speaking populations, it has not been validated in Spanish-speaking children. This study aimed to evaluate comprehension and response accuracy of a Spanish-adapted MMQT in soccer players aged 4-8 years. We conducted a cross-sectional observational study in Montevideo, Uruguay, between July and October 2024. Eighty-eight male soccer players aged 4-8 years were assessed at halftime using a Spanish-adapted version of the MMQT. Comprehension was evaluated by asking participants to reformulate each question. Associations between age, comprehension, and response accuracy were analyzed using chi-square or Fisher’s exact tests and logistic regression models. No statistically significant association was found between age and either comprehension or accuracy. Overall comprehension exceeded 96%. However, Question 4 („Which team won the last match?“) consistently showed a lower correct response rate across all ages. Our findings reinforce previous observations showing that questions assessing recall of past events can be challenging for younger children and suggest caution when evaluating MMQT responses in this age group. The Spanish-adapted MMQT demonstrates high comprehension and may be suitable for sideline concussion screening in children aged 5-8 years. However, Question 4 appears less reliable and should be reconsidered in future versions. A conservative approach is recommended, whereby any incorrect response warrants removal from play for further evaluation.

21 Common MRI findings in pre-signing medical assessments of professional soccer players

Reference: BMJ Open Sport Exerc Med. 2026 Apr 30;12(2):e003233. doi: 10.1136/bmjsem-2026-003233. eCollection 2026.
Authors: Elena Höhne, Scherwin Mahmoudi, Thomas Vogl et al.
Download link: https://bmjopensem.bmj.com/content/bmjosem/12/2/e003233.full.pdf
Summary: In professional soccer, comprehensive musculoskeletal assessments are performed prior to player transfers to evaluate both the current condition and future risk of injury. MRI plays a crucial role in this process, effectively revealing musculoskeletal findings even in the absence of symptoms. This study presents common musculoskeletal MRI findings in professional soccer players undergoing pre-signing assessments and their associations with age, playing position and footedness. In this retrospective study, musculoskeletal 3 Tesla MRI scans obtained during pre-signing medical assessments of professional soccer players from August 2019 to March 2025 were included. Clinical data were extracted from medical records and supplemented with publicly available player information. Structural abnormalities exceeding expected physiological or age-related adaptations were systematically recorded and categorised according to institutional reporting practice. A total of 50 professional soccer players (mean age 25.4±4.7 years) were included. The most frequent MRI findings were secondary cleft signs and lumbar degenerative disc changes (in 21/50 and 20/50 players), followed by chondropathy of the knee (34%), labral degeneration (26%), femoroacetabular impingement (22%) and other soft tissue or bone-related changes. The prevalence of secondary clefts differed significantly across playing positions (χ²=8.07, p=0.045) with strikers showing the highest proportion (68.75%) compared with other groups. Routine MRI screening in professional soccer players revealed typical frequent structural changes, even in the absence of symptoms. While most findings were consistently distributed across positions, some showed variation depending on playing position. These results highlight the value of early imaging in guiding individualised monitoring and injury prevention strategies.

22 Mindful Sport Performance Enhancement in Youth Soccer: A Randomized Active-Control Trial of Objective Performance Under Pressure and Psychological Outcomes

Reference: J Sport Exerc Psychol. 2026 May 5:1-12. doi: 10.1123/jsep.2026-0002. Online ahead of print.
Authors: Alireza Farsi, Javad Shakerd, Ebrahim Moteshareie, Erfan Sedighi
Summary: This randomized controlled trial examined whether Mindful Sport Performance Enhancement (MSPE) improves objective performance under pressure, increases flow, and reduces competitive anxiety and aggression in youth soccer. Fifty-two male academy outfield players were randomized to 6 weeks of MSPE or an education-based active attention control. Assessments were completed pre, post, and 3-month follow-up; 90-min matches were framed as selection-relevant trials and video-coded by blinded raters. Mixed analyses of variance showed a significant Group × Time interaction for under pressure performance (p < .001): MSPE improved at posttest and remained superior at follow-up. Relative to education-based active attention control, flow increased and somatic anxiety decreased, with smaller effects for cognitive anxiety and aggression; aggression was not maintained. Findings were robust to sensitivity analyses using linear mixed-effects model. Exploratory mediation analyses provided no clear evidence that changes in psychological variables explained performance gains. Overall, MSPE offers a practical, field-ready approach for supporting under pressure performance and related psychological outcomes in youth soccer.