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 Platelet-Rich Plasma (PRP)/stem-cell therapy for a partial torn ulnar collateral ligament in a professional football player: case report

Reference: J Can Chiropr Assoc. 2025 Dec;69(4):414-424. Epub 2025 Dec 30.
Authors: Noah Lane, George Austin Rees, Kevin D’Angelo
Summary: Present a unique case of non-operative management of a partial ulnar collateral ligament (UCL) tear where the athlete was able to return to performance-based training in a brief six-week period. A 29-year-old male running back presented to a sports specialist chiropractor for post-injection management of a grade 2 partial tear of the right UCL treated with ultrasound-guided platelet-rich plasma (PRP) and stem cell injections. Physical exam testing found limitations in elbow range of motion (ROM) as well as positive orthopedic tests confirming a UCL injury including the milking maneuver, and dynamic valgus stress test. Management consisted of multimodal chiropractic care including active release therapy (ART), electroacupuncture and rehabilitation exercises. This patient’s improved strength and function without surgical intervention highlights the possible role of biologic injections as a form of non-operative management when combined with multimodal care to accelerate recovery from UCL injuries in elite athletes.

#2 The impact of microdosed plyometric training on speed and explosive abilities of football players during the pre-season

Reference: BMC Sports Sci Med Rehabil. 2026 Feb 5. doi: 10.1186/s13102-026-01556-5. Online ahead of print.
Authors: Marián Škorik, Tomáš Kalina, Martin Pupiš, Michal Hrubý
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01556-5_reference.pdf

#3 Measuring football fever through wearable technology

Reference: Sci Rep. 2026 Feb 5;16(1):3866. doi: 10.1038/s41598-026-36182-1.
Authors: Timo Adam, Jonas Bauer, Christian Deutscher, Christiane Fuchs, Tamara Schamberger, David Winkelmann
Download link: https://www.nature.com/articles/s41598-026-36182-1.pdf
Summary: Football is the world’s most popular sport, evoking strong physiological and emotional responses among its fans. Yet, the specific reactions to fan involvement have received little attention in the literature. In this paper, we quantify the resulting physiological responses through a unique case study from professional football: the 2025 cup final of the German Football Association (DFB) between first-division club VfB Stuttgart and third-division club Arminia Bielefeld. We collected high-resolution smartwatch data, including heart rate and stress level, from 229 Arminia Bielefeld fans over approximately 12 weeks, complemented by survey responses on identification with the club, match attendance, and personal characteristics from a subset of 37 participants. By combining physiological data with survey information, we analyse variations in emotional arousal across individuals and contexts, measured by physiological reactions to the cup final. This approach provides rare, data-driven insights into the football fever that captivates fans during high-stakes competitions. Furthermore, we compare the vital parameters recorded on the day of the match with baseline levels on non-matchdays throughout the entire observation period. Our findings reveal pronounced physiological responses among fans, beginning hours before the match and peaking at kick-off.

#4 Characteristics of musculoskeletal injuries in youth football: a prospective study

Reference: Phys Sportsmed. 2026 Feb 7:1-7. doi: 10.1080/00913847.2026.2626298. Online ahead of print.
Authors: Tainá de Mattos Leão, Rafaela Dos Santos Borek, Robertto de Oliveira Basso, Cassio Zini, Eduardo Bolicenha Simm, Guilherme Costa, Fábio Picoli, Juan Henrique Szymczak Conde, Renato Nisihara
Summary: Musculoskeletal injuries are common in youth football and can impact athletes‘ development and performance. Understanding their incidence and characteristics is essential for prevention and management. To analyze the incidence and characteristics of musculoskeletal injuries in youth categories of a Brazilian football club over one competitive season and assess associations with age group, playing position and training load. We included 180 male athletes from four youth categories (U-11/13, U-15, U-17, U-20) monitored during the 2022 season. Data were collected from medical records, including injury diagnosis and severity, training load metrics (sRPE, TRIMP, ACWR, GPS).Injuries were defined as any condition causing at least one day of absence. Statistical analyses included correlations and group comparisons. A total of 181 injuries were recorded; 64.4% of athletes sustained at least one. Muscle injuries were most frequent (59%), followed by joint injuries (19.8%). The U-20 group had the highest incidence (33%), and forwards were most affected (34.2%). Bone injuries caused the longest absences (p < 0.0001). No significant associations were found between training load and injury outcomes. Injury patterns varied by age and position. Muscle injuries predominated, highlighting the importance of integrated monitoring of injury characteristics, athlete profile, and physical demands to support injury prevention and early management in youth football.

#5 Impact of breast health education and individual sports bra prescription on elite female football match officials

Reference: J Sports Sci. 2026 Feb 3:1-12. doi: 10.1080/02640414.2026.2623565. Online ahead of print.
Authors: Jenny Burbage, Emily Paines, Chloe G Errington, Nathalie Y Qaqaya, Werner F Helsen, Caroline A Tarnowski, Ian Rollo, Melissa E A Jones, Joanna Wakefield-Scurr 
Summary: Female football (soccer) officials face unique physical demands and equipment constraints, yet their breast health needs remain under-researched. This study investigated bra usage, issues and preferences among elite and national-level female football match officials and evaluated the effect of a targeted breast health intervention. Baseline questionnaires were completed by 104 officials (mean age 34 ± 5 years), assessing breast and bra knowledge, usage, preferences, pain and equipment-related issues. All 104 participants attended a one-hour online breast health education session. Of these, a subgroup of 20 elite officials also received a bra assessment and were prescribed a high-support bra. Four weeks later, follow-up questionnaires assessed changes in breast health knowledge and compared personal versus prescribed sports bras for fit, support, pain and compatibility with upper-body equipment. At baseline, 93% of participants reported at least one breast- or bra-related issue; 25% identified problems due to bra-equipment interaction. Breast health knowledge improved significantly post-intervention (p < 0.001). Satisfaction was significantly higher with the prescribed bra across fit, support and reduced breast pain (all p < 0.05). Targeted breast health education and individual bra prescription improved knowledge, comfort and support. Breast-related and bra-equipment interaction issues are prevalent, highlighting the need for improved sports bra design and integration with upper-body equipment.

#6 The Impact of the FIFA 11+ Injury Prevention Program on Injury Incidence in Football Athletes: A Systematic Review of Randomized Controlled Trials

Reference: Cureus. 2025 Dec 31;17(12):e100463. doi: 10.7759/cureus.100463. eCollection 2025 Dec.
Authors: Purvi Patel, Malkesh Shah
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12856364/pdf/cureus-0017-00000100463.pdf
Summary: Football is associated with a high incidence of lower-extremity injuries, creating a substantial burden on athletes, teams, and healthcare systems. The Fédération Internationale de Football Association (FIFA) 11+ warm-up program was developed as a structured neuromuscular training routine to reduce injury risk by improving strength, balance, proprioception, and movement control. This systematic review synthesised controlled trials evaluating the effectiveness of the standard FIFA 11+ program among football players across youth, collegiate, and adult levels. Electronic databases were searched from 2008 to 2025 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five controlled trials met the inclusion criteria. Due to heterogeneity in injury definitions, adherence reporting, and exposure-hour documentation, a narrative synthesis was performed. Across all studies, teams performing the FIFA 11+ demonstrated meaningful reductions in overall and lower-extremity injury incidence compared with those using traditional warm-ups, with preventive effects ranging from approximately 30% to 46%. The program’s effectiveness appeared to be mediated by improvements in neuromuscular control, trunk and hip stability, eccentric strength, and dynamic alignment during high-risk football movements such as cutting and landing. Adherence emerged as the primary determinant of success. These findings support the FIFA 11+ as an effective, low-cost, and accessible strategy for reducing football injuries when implemented consistently.

#7 Physiological determinants of heart rate responses and bout-to-bout stability during 2v2 and 4v4 small-sided games in football players

Reference: Front Public Health. 2026 Jan 16:14:1766471. doi: 10.3389/fpubh.2026.1766471. eCollection 2026.
Authors: Aleksandra Kisilewicz, Małgorzata Smoter, Robert Trybulski
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12855520/pdf/fpubh-14-1766471.pdf
Summary: Injury prevention in sport is increasingly recognized as a health priority, and monitoring internal load during routine training offers a pragmatic pathway to reduce overuse risk and support long-term athlete health. This study examined the extent to which three practical physiological markers (resting heart rate (HRrest), submaximal warm-up heart rate after 60-s recovery (HRR), and Yo-Yo IR1 HRmax) explain mean heart rate (HRmean) and bout-to-bout variability (CV%) during two commonly used small-sided game (SSG) formats (2v2 and 4v4) in football players. Forty male amateur players completed HRrest, HRR, and Yo-Yo IR1 testing, followed by randomized, counterbalanced 2v2 and 4v4 SSG sessions (3 × 3-min bouts). HRmean and CV% were computed for each format. Associations were assessed using Pearson correlations and multiple linear regression. HRmean did not differ significantly between 2v2 and 4v4 (166.9 ± 5.1 vs. 165.3 ± 6.0 bpm; t₃₉ = 1.35, p = 0.19), whereas CV% was lower in 2v2 (2.05 ± 1.16%) than 4v4 (2.85 ± 1.43%; t₃₉ = -2.52, p = 0.016). In 2v2, no physiological marker correlated with HRmean (all p > 0.30). In 4v4, HRR showed a moderate significant correlation with HRmean (r = 0.36, p = 0.023). Regression models explained 3.1% (2v2) and 16.3% (4v4) of HRmean variance, with HRR emerging as the only significant predictor in 4v4 (β = 0.20, p = 0.047). In a repeated-measures linear mixed-effects model (random intercept for player; fixed effect for format), the resting HR × format interaction for CV% was significant (p = 0.016). HRR is the sole physiological marker meaningfully associated with internal load during SSGs (and only in 4v4) while neither HRmean nor CV% in 2v2 is explained by the tested markers. More constrained formats (2v2) produce more stable cardiovascular responses. By identifying simple heart-rate-based indicators and game formats that yield more stable cardiovascular responses, these findings can inform scalable load-management strategies that help mitigate maladaptive overreaching and contribute to broader injury-prevention efforts in athletic populations, although future studies are necessary to confirm such hypothesis.

#8 Effects of recreational football on body composition, cardiometabolic health, and functional performance in children and adolescents: a systematic review and meta-analysis

Reference: Front Physiol. 2026 Jan 16:16:1707395. doi: 10.3389/fphys.2025.1707395. eCollection 2025.
Authors: Yanzhao Lei, Yanmei Ding, Bo Wang, Hengzhi Deng, Mingyue Yin, Kai Xu et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12855146/pdf/fphys-16-1707395.pdf
Summary: The systematic review and meta-analysis aimed to evaluate the effects of recreational football on body composition, cardiometabolic health, and functional performance in children and adolescents. Additionally, it explored potential moderators through subgroup analyses. A systematic search was conducted in six databases in May 2025. A random-effects model was employed for the meta-analysis, and effect sizes were reported as standardized mean differences (SMD, Hedges‘ g). Subgroup and sensitivity analyses were conducted to examine sources of heterogeneity. A total of 20 studies (N = 2,906; age range: 8-17 years) were included. Of the participants, 1,524 (52.44%) were male, 1,174 (40.40%) were female, and 208 (7.16%) did not clearly report their gender. Recreational football significantly reduced BMI (SMD = -0.13 [-0.24, -0.02]), body fat percentage (SMD = -0.37 [-0.63, -0.11]), and waist circumference (SMD = -1.38 [-2.65, -0.11]), with a slight increase in lean mass (SMD = 0.13 [0.02, 0.24]). It also reduced mean arterial pressure (SMD = -1.06 [-2.03, -0.10]), systolic blood pressure (SMD = -0.71 [-1.19, -0.23]), and triglycerides (SMD = -0.95 [-1.74, -0.15]), while having no effect on diastolic blood pressure, resting heart rate, VO2peak, blood glucose, or cholesterol. Additionally, it improved interval endurance (SMD = 0.15 [0.04, 0.25]), sprint speed (SMD = -0.72 [-1.22, -0.22]), standing long jump (SMD = 0.53 [0.10, 0.97]), and balance (SMD = 0.84 [0.21, 1.46]), but had no effect on vertical jump. Subgroup analyses showed greater reductions in BMI (g = -0.54) and body weight (g = -0.89) in overweight/obese individuals, and significant weight improvement in adolescents >12 years (g = -1.35). Longer interventions (≥12 weeks) and higher frequencies (>2 sessions/week) were associated with greater body fat reduction (g = -0.82 and g = -0.74), with reductions in resting heart rate observed mainly in interventions ≥12 weeks (g = -0.72). According to the GRADE assessment, the overall quality of evidence was rated as low to very low. Recreational football is efficacious in improving body composition, select cardiometabolic risk factors, and physical performance in children and adolescents, especially individuals classified as overweight or obese. Even with limitations in sample size, intervention diversity, and methodological quality, resulting in an overall low to low quality assessment of the evidence, the comprehensive evidence still provides preliminary quantitative support for incorporating recreational football into youth health promotion; future efforts will require larger samples, standardized protocols, and rigorous design to enhance the strength of the evidence. Based on existing evidence, a reference protocol may consist of a 12-week program with 2-3 weekly sessions (45-60 min each), including a FIFA 11+ warm-up, 3-4 bouts of 4-6 min at up to 80% HRmax with 2-min recovery intervals, and a cool-down.

#9 High-intensity interval training improves the reactive strength index and motor ability of youth football players

Reference: BMC Sports Sci Med Rehabil. 2026 Feb 2. doi: 10.1186/s13102-026-01560-9. Online ahead of print.
Authors: Serkan Kızılca, Muhammed Zahit Kahraman, Sedat Okut, Ersin Arslan, Ömer Faruk Bilici, İsmail Çelik, Tayfun İşlen, Sebahattin Altıntaş, Muhammed Fatih Bilici
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01560-9_reference.pdf
Summary: The aim of this randomized controlled trial was to determine the effects of a four-week running-based high-intensity interval training (HIIT) intervention on the reactive strength index (RSI) and motor abilities in youth football players. In this context, the contributions of the running-based HIIT protocol HIIT protocol, implemented in addition to regular football training, were evaluated on performance indicators such as speed, back strength, change of direction (COD), and countermovement jump (CMJ). This study aims to contribute to the development of scientifically grounded training programs to support performance improvement in youth football players. A quantitative research design was employed in this study, specifically a randomized pretest-posttest controlled experimental design. Twenty male youth football players, aged 11-13 years, who voluntarily participated in the study were randomly allocated to either the experimental group (EG; n = 10) or the control group (CON; n = 10). The EG participated in a running-based HIIT program three times per week for four weeks by replacing a low-to-moderate-intensity technical-tactical segment of their regular football training, whereas the CON continued with only regular football training during this period without any additional training volume. The players underwent RSI, 10 m, 20 m, and 30 m sprint tests, back strength tests, the Illinois Agility Test, and CMJ tests both before the training sessions and at the end of the four-week intervention. According to the repeated-measures ANOVA results, pretest values did not differ significantly between the groups (p > .05). Over the 4-week period, significant improvements with large effect sizes were observed in RSI, sprint performance (10, 20, 30 m), back strength, COD, and CMJ tests (p < .05; ηp² = 0.29-0.55). Significant group × time interactions were also detected for all variables, again with large effect sizes (p < .05; ηp² = 0.20-0.30), indicating greater improvements in the EG compared to the CON. However, despite these favourable within-group changes, between-group post-test comparisons did not reach statistical significance. This study revealed that a 4-week HIIT intervention applied to youth male football players had positive effects on the RSI and motor abilities, as evidenced by large within-group improvements and significant group × time interactions, despite the absence of statistically significant between-group post-test differences. These findings suggest that HIIT protocols should be integrated into training programs as an effective strategy to improve explosive strength, COD, and overall functional performance in young athletes.

#10 Self-Reported Hip Crepitus Is Prevalent in Football Players With Hip/Groin Pain, but Is It Associated With Early Hip Osteoarthritis Structural Features? A Longitudinal Study

Reference: J Orthop Sports Phys Ther. 2026 Feb;56(2):119-127. doi: 10.2519/jospt.2025.13474.
Authors: Fernanda Serighelli, Kay M Crossley, Matthew G King, Mark J Scholes, Joanne L Kemp, Rintje Agricola, Richard B Souza, Thomas M Link; FORCe group; Joshua J Heerey, Danilo De Oliveira Silva
Download link: https://www.jospt.org/doi/epdf/10.2519/jospt.2025.13474
Summary: The aim was to compare the prevalence of self-reported hip crepitus between football (soccer and Australian football) players with and without hip/groin pain. In players with hip/groin pain, to (2) explore the association of hip crepitus with early hip osteoarthritis structural features, and (3) explore the association between hip crepitus and the change in these features over 2 years. Data from 178 subelite football players with hip/groin pain and 60 pain-free controls were analyzed. The presence and severity of hip crepitus were assessed using a single item of the Copenhagen Hip and Groin Outcome Score and the International Hip Outcome Tool-33, respectively. Participants had radiographs and 3-Tesla magnetic resonance imaging. Bony hip morphology was evaluated using the alpha angle and lateral center-edge angle. The scoring of hip osteoarthritis with magnetic resonance imaging classification was used to evaluate cartilage defects and labral tear presence, location, and severity. Regression models explored the prevalence and associations of self-reported hip crepitus with early hip osteoarthritis features. Football players with hip/groin pain had a higher prevalence (prevalence ratio = 5.0; 95% CI: 2.5, 10.2) of hip crepitus compared to controls. Hip crepitus was only associated with the number of cartilage subregions affected in the hip/groin pain group (odds ratio = 2.08; 95% CI: 1.05, 4.11; P = .03) at baseline, but not with other features. Football players with hip/groin pain had a higher prevalence and severity of hip crepitus compared to controls. Hip crepitus was associated with the number of cartilage subregions affected in football players. 

#11 Acute beetroot juice supplementation enhances short duration high-intensity exercise performance and influences muscle oxygenation in football players

Reference: Sci Rep. 2026 Jan 31. doi: 10.1038/s41598-026-37514-x. Online ahead of print.
Authors: Melike Nur Eroglu, Beril Kose, İpek Eroglu Kolayis, Bahtiyar Haberal
Download link: https://www.nature.com/articles/s41598-026-37514-x_reference.pdf
Summary: Beetroot juice (BJ), a nitrate-rich supplement, may enhance exercise performance, but its acute effects on anaerobic power and muscle oxygenation in football players are unclear. This study investigated these effects during a Wingate test in trained male footballers. In a randomized, crossover, double-blind, placebo-controlled design, 16 male football players (age: 18.2 ± 0.4 years, weight: 69.6 ± 6.5 kg, height: 177.5 ± 5.5 cm) consumed 140 mL of BJ (12.8 mmol nitrate) or a placebo (blackcurrant juice (< 0.1 mmol nitrate)). After 2.5 h, a 30-s Wingate test was performed. Muscle oxygenation, heart rate, blood pressure, and blood lactate were assessed. BJ supplementation increased peak power (placebo: 720.33 ± 107.78 W; BJ: 803.50 ± 127.23 W, p = 0.002) and mean power (placebo: 541.23 ± 62.05 W; BJ: 581.42 ± 80.09 W, p = 0.001), and reduced the time to peak power (placebo: 7.32 ± 0.84 s; BJ: 8.10 ± 0.94 s, p = 0.032) compared to placebo. Muscle oxygenation did not differ during exercise (p > 0.05); however, post-exercise muscle oxygen saturation was higher (∼10%, p = 0.017) and deoxygenated haemoglobin was lower (∼13%, p = 0.019) with BJ. Post-exercise blood lactate levels were higher in BJ compared to placebo (p < 0.05). Blood pressure at all time points and heart rate during exercise did not differ between conditions (p > 0.05). Acute BJ supplementation increases anaerobic power output and post-exercise muscle oxygenation in football players, without affecting heart rate or blood pressure.

#12 The Effectiveness of Transcranial Direct Current Stimulation (tDCS) in Improving Performance in Soccer Players-A Scoping Review

Reference: J Clin Med. 2026 Feb 5;15(3):1281. doi: 10.3390/jcm15031281.
Authors: James Chmiel, Donata Kurpas
Download link: https://www.mdpi.com/2077-0383/15/3/1281
Summary: Transcranial direct current stimulation (tDCS) is increasingly used by athletes, yet sport-performance-enhancement findings are mixed and often small, with outcomes depending on stimulation target, timing, and task demands. Aim: This scoping review mapped and synthesized the soccer-specific trial evidence to identify (i) which tDCS targets and application schedules have been tested in soccer players, (ii) which soccer-relevant outcomes show the most consistent immediate (minutes-hours) or training-mediated benefits, and (iii) where evidence gaps persist. We conducted a scoping review of clinical trials in footballers, following review best-practice guidance (PRISMA-informed) and a preregistered protocol. Searches (August 2025) spanned PubMed/MEDLINE, ResearchGate, Google Scholar, and Cochrane, using combinations of „football/soccer“ and „tDCS/transcranial direct current stimulation,“ with inclusion restricted to trials from 2008-2025. Dual independent screening was applied. Of 47 records identified, 21 studies met the criteria. Across these, the total N was 593 (predominantly male adolescents/young adults; wide range of levels). Prefrontal protocols-most commonly left-dominant dorsolateral prefrontal cortex (DLPFC) (+F3/-F4, ~2 mA, ~20 min)-most consistently improved post-match recovery status/well-being (e.g., fatigue, sleep quality, muscle soreness, stress, mood), and when repeated and/or paired with practice, shortened decision times and promoted more efficient visual search. Effects on classic executive tests were inconsistent, and bilateral anodal DLPFC under fatigue increased risk-tolerant choices. Motor-cortex targeting (C3/C4/Cz) rarely changed rapid force-power performance after a single session-e.g., multiple well-controlled trials found no immediate CMJ gains-but when paired with multi-week training (core/lumbar stability, plyometrics, HIIT, sling), it augmented strength, jump height, sprint/agility, aerobic capacity, and task-relevant EMG. Autonomic markers (exercise HR, early HR recovery) showed time-dependent normalization without specific tDCS effects in single-session, randomized designs. In contrast, a season-long applied program that added prefrontal stimulation to standard recovery reported significantly reduced creatine kinase. Across studies, protocols and masking were athlete-friendly and rigorous (~2 mA for ~20 min; robust sham/blinding), with only mild, transient sensations reported and no serious adverse events. In soccer players, tDCS shows a qualified pattern of benefits that follows a specificity model: prefrontal stimulation can support post-match recovery status/well-being and decision efficiency, while M1-centered stimulation is most effective when coupled with structured training to bias neuromuscular adaptation. Effects are generally modest and heterogeneous; practitioners should treat tDCS as an adjunct, not a stand-alone enhancer, and align montage × task × timing while monitoring individual responses.

#13 Isokinetic Strength Recovery and Fear of Re-Injury After ACL Reconstruction in Male Soccer Players: A Retrospective Cohort Study

Reference: J Clin Med. 2026 Feb 4;15(3):1243. doi: 10.3390/jcm15031243.
Authors: Matteo Interlandi, Luca Santini, Sebastiano Zuppardo, Franco Merlo, Giovanni Grazzini, Gilberto Martelli
Download link: https://www.mdpi.com/2077-0383/15/3/1243
Summary: Persistent strength deficits and psychological impairments may compromise return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR). We investigate the relationship between thigh muscle isokinetic strength recovery at six months after ACLR and long-term psychological outcomes related to RTS in competitive male soccer players. Sixty male soccer players who underwent primary ACLR with bone-patellar tendon-bone autograft were retrospectively analyzed. Isokinetic testing of quadriceps and hamstrings was performed one week before surgery and six months post-surgery at 90°/s and 180°/s. Limb symmetry index (LSI) was calculated both pre- and post-operatively. At long-term follow-up (mean ≈ 4 years after RTS), athletes completed questionnaires assessing RTS status, ACL re-injuries, sport-related perceptions, and kinesiophobia using the Tampa Scale for Kinesiophobia (TSK). Statistical analyses were conducted to explore associations between post-operative LSI and TSK scores and to compare psychological and neuromuscular outcomes between athletes with and without ACL re-injury. Absolute quadriceps and hamstring peak torque values significantly increased from pre- to post-surgery, with quadriceps strength deficits persisting only in the operated limb. However, quadriceps LSI significantly decreased post-operatively, while hamstring LSI remained stable. Pearson correlation analysis revealed a weak positive association between post-operative quadriceps LSI at 90°/s and TSK scores (r = 0.34). Overall, RTS rate was 91.7%, but a second ACL injury occurred in 18.2% of athletes. No significant differences were observed between re-injured and non-re-injured athletes in TSK scores or post-operative LSI values at either angular velocity (all p > 0.29). High kinesiophobia (TSK ≥ 37) was present in 56.7% of the cohort at long-term follow-up. Despite significant strength gains, quadriceps limb symmetry worsened six months after ACLR, with deficits confined to the operated limb, suggesting persistent neuromuscular inhibition. These physical deficits coexist with long-term kinesiophobia despite high RTS rates. The weak associations between strength symmetry and psychological outcomes highlight the multifactorial nature of RTS and support the need for an integrated physical, psychological, and neuro-cognitive approach to rehabilitation and RTS decision-making.

#14 Effects of 8 Weeks of Neuromuscular and SAQ Training on Physical Performance in Youth Soccer Players

Reference: J Clin Med. 2026 Feb 3;15(3):1202. doi: 10.3390/jcm15031202.
Authors: Yu-Bin Lee, Kwang-Jin Lee, Se-Young Seon, Keun-Ok An
Download link: https://www.mdpi.com/2077-0383/15/3/1202
Summary: Adolescent soccer players are exposed to elevated injury risk due to rapid musculoskeletal development and high physical demands. Neuromuscular training (NMT) and speed-agility-quickness (SAQ) training are widely used to enhance performance and reduce injury risk in youth athletes. While both approaches are effective, comparative evidence regarding their modality-specific performance adaptations remains limited. Furthermore, few studies have discussed how such performance data may inform evidence-based or data-driven training selection in youth sports contexts. Thirty-six male youth soccer players with at least three years of playing experience, affiliated with Team A in Gyeonggi-do and Team B in Chungcheongbuk-do, participated in the study (NMTG, n = 21; SAQG, n = 15). Participants completed either an NMT or SAQ training program for eight weeks. To objectively assess exercise performance, pre- and post-tests were conducted measuring dynamic balance, vertical jump, zigzag run, and carioca. Findings revealed a significant main effect of time for lower limb power (p < 0.05), but no significant group × time interaction, indicating that both NMTG and SAQG improved significantly over the 8-week period. Conversely, significant interaction effects were found for agility (p < 0.001), with SAQG demonstrating superior enhancements compared to NMTG. Dynamic balance showed no significant time effect or interaction. While NMTG and SAQG are equally effective for enhancing lower limb power, SAQG provides modality-specific advantages for agility in youth soccer players. These results emphasize time-dependent adaptations for power and the distinct benefits of SAQG for multi-directional speed. These adaptation profiles offer a data-driven framework for optimizing training selection in youth athletes.

#15 Balance Assessments Using Smartphone Sensor Systems and a Clinician-Led Modified BESS Test in Soccer Athletes with Hip-Related Pain: An Exploratory Cross-Sectional Study

Reference: Sensors (Basel). 2026 Feb 6;26(3):1061. doi: 10.3390/s26031061.
Authors: Alexander Puyol, Matthew King, Charlotte Ganderton, Shuwen Hu, Oren Tirosh
Download link: https://www.mdpi.com/1424-8220/26/3/1061
Summary: The Balance Error Scoring System (BESS) is the most practiced static postural balance assessment tool, which relies on visual observation, and has been adopted as the gold standard in the clinic and field. However, the BESS can lead to missed and inaccurate diagnoses-because of its low inter-rater reliability and limited sensitivity-by missing subtle balance deficits, particularly in the athletic population. Smartphone technology using motion sensors may act as an alternative option for providing quantitative feedback to healthcare clinicians when performing balance assessments. The primary aim of this study was to explore the discriminative validity of an alternative novel smartphone-based cloud system to measure balance remotely in soccer athletes with and without hip pain. This is an exploratory cross-sectional study. A total of 64 Australian soccer athletes (128 hips, 28% females) between 18 and 40 years completed single and tandem stance balance tests that were scored using the modified BESS test and quantified using the smartphone device attached to their lower back. An Exploratory Factor Analysis (EFA) and a Clustered Receiver Operating Characteristic (ROC) using an Area Under the Curve (AUC) were used to explore the discriminative validity between the smartphone sensor system and the modified BESS test. A Linear Mixed-Effects Analysis of Covariance (ANCOVA) was used to determine any statistical differences in static balance measures between individuals with and without hip-related pain. EFA revealed that the first factor primarily captured variance related to smartphone measurements, while the second factor was associated with modified BESS test scores. The ROC and the AUC showed that the smartphone sway measurements in the anterior-posterior and mediolateral directions during single-leg stance had an acceptable to excellent level of accuracy in distinguishing between individuals with and without hip-related pain (AUC = 0.72-0.80). Linear Mixed-Effects ANCOVA analysis found that individuals with hip-related pain had significantly less single-leg balance variability and magnitude in the anteroposterior and mediolateral directions compared to individuals without hip-related pain (p < 0.05). Due to the ability of smartphone technology to discriminate between individuals with and without hip-related pain during single-leg static balance tasks, it is recommended to use the technology in addition to the modified BESS test to optimise a clinician-led assessment and to further guide clinical balance decision-making. While the study supports smartphone technology as a method to assess static balance, its use in measuring balance during dynamic movements needs further research.

#16 Strategic daytime napping enhances agility and lowers perceived exertion but does not improve fatigue resistance in adolescent soccer players

Reference: Sci Rep. 2026 Feb 12. doi: 10.1038/s41598-026-39637-7. Online ahead of print.
Authors: Mertkan Öncü, Özgür Eken, Monira I Aldhahi
Download link: https://www.nature.com/articles/s41598-026-39637-7_reference.pdf
Summary: Daytime naps are increasingly adopted by athletes to alleviate subjective fatigue and restore alertness, yet their impact on high-intensity anaerobic tasks remains unclear. Both nap duration and circadian timing may modulate psychomotor readiness, perceived exertion, and fatigue resistance, but evidence from team-sport settings is limited. This study aimed to determine how different daytime nap durations (25 vs. 45 min) influence agility, repeated-sprint performance, and psychophysiological responses—including perceived exertion and mood—in adolescent soccer players. Sixteen competitive male adolescent soccer players (all intermediate chronotypes) completed three randomized, crossover sessions: no nap (N0), 25-min nap (N25), and 45-min nap (N45). Nap compliance was objectively verified by actigraphy. After a 60-min post-nap wake-up period, participants performed the Pro Agility Test and a repeated-sprint ability (RSA) protocol. Psychophysiological outcomes included ratings of perceived exertion (RPE), Hooper Index, visual analogue scales (VAS) for alertness, and Profile of Mood States (POMS). Agility improved in a clear dose–response pattern (N0 = 5.40 ± 0.34 s; N25 = 5.18 ± 0.23 s; N45 = 4.98 ± 0.29 s; p < 0.001, ηp2 = 0.57). RPE was significantly lower after N45 versus N0 (Δ = −1.4; p < 0.01, ηp2 = 0.45). RSA indices showed no overall condition effect, although best sprint time improved after N45 versus N25 (p < 0.01) with greater fatigue accumulation across repeated sprints (p < 0.05). Mood analysis revealed positive associations between fatigue and RPE and negative associations between vigor and RPE, indicating that mood states are associated with perceived exertion. A 45-min early-afternoon nap meaningfully enhanced agility and reduced perceived exertion but did not improve fatigue resistance during repeated sprints. Coaches should weigh the neuromuscular and perceptual benefits of longer naps against potential fatigue trade-offs when designing pre-competition recovery strategies.

#17 Comparing the effect of mental fatigue-inducing models on selected cognitive and technical performance aspects in young soccer players

Reference: Sci Rep. 2026 Feb 12. doi: 10.1038/s41598-026-39936-z. Online ahead of print.
Authors: Amin Soltani, Daniel Memmert, Rasoul Rezaie, Gholamhosein Nazemzadegan, Maryam Koushkie Jahromi
Download link: https://www.nature.com/articles/s41598-026-39936-z_reference.pdf
Summary: Mental fatigue is a well-documented performance inhibitor in team sports, Therefore, identifying strategies to attenuate mental fatigue seems necessary. This study aimed to evaluate and compare four distinct training models—Modified Stroop, SAFT90, T-SAFT90, and a combined T-SAFT90 + Stroop protocol—to identify the most effective method for inducing mental fatigue under controlled laboratory conditions, as a potential model for brain endurance training (BET) research in young soccer players. Fifteen male players (aged 16–18) participated in a randomized cross-over study. Mental fatigue was assessed via a Visual Analogue Scale (VAS; primary outcome), cognitive performance (secondary outcomes) was evaluated through response time, response accuracy, working memory capacity, visual Scanning Identification, and auditory pattern recognition. Technical performance was measured using penalty time, movement time and passing accuracy in the Loughborough Soccer Passing Test (LSPT; primary outcomes). All protocols significantly increased mental fatigue, with the largest effect observed in the combined T-SAFT90 + Stroop model. Response accuracy declined across all models, while response time worsened in the Stroop and T-SAFT90 conditions. Penalty time increased in the Stroop and T-SAFT90 protocols, whereas passing accuracy decreased most significantly in the combined model. In summary, under standardized, controlled conditions, the combined cognitive-physical training model induced the highest mental fatigue and most consistently altered cognitive and technical performance. These findings provide preliminary evidence supporting its potential as a BET model for research and structured training environments, though ecological validation in real soccer contexts remains necessary.

#18 Quantification of High-Intensity Change of Directions and Single-Leg Decelerations Between Limbs Within Elite Youth Soccer Match Play

Reference: Int J Sports Physiol Perform. 2026 Feb 12:1-7. doi: 10.1123/ijspp.2025-0381. Online ahead of print.
Authors: Lewis Grant, Matthew Wyon, Ross Cloak
Summary: Soccer requires repeated changes of direction (COD) and single-leg decelerations (SLD), which accrue considerable mechanical stress on the lower limbs. These actions place significant demands on the players‘ musculoskeletal system. An uneven utilization of these actions between limbs, arising from disparities in neuromuscular control and skill acquisition, may lead to asymmetries and increased injury risk. This study aimed to examine the effects of player position and footedness on the frequency of intense CODs, SLDs, and the total sum of the 2 actions (TOT) performed by the dominant and nondominant foot in elite male youth soccer players. Twenty-five elite English youth soccer players were grouped by their playing positions (lateral: full-backs and wide midfielders; central: center defenders, center midfielders, and strikers) and footedness (left or right footed). High-intensity CODs and SLDs were identified using video analysis and GPS data across 6 matches. The frequency and distribution of these actions were analyzed to assess the impact of player position and limb dominance. No significant differences were found in the percentage distribution of SLDs or TOT between the central and lateral groups. However, central players exhibited a significantly greater imbalance in COD frequency compared with lateral players (51.8% [31.5%] vs 29.9% [31.1%]; P < .05; d = 0.70). Players performed more CODs in the direction opposite to their dominant limb, indicating a preference for using the dominant limb as the plant limb (4.6 [3.2] vs 3.7 [2.6]; P < .05; d = 0.31). The study highlights the mechanical and positional demands placed on soccer players, with central players showing greater COD frequency asymmetry.