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 Development of team-based and individualised speed zone thresholds for elite club-level women’s soccer
Reference: Sci Med Footb. 2026 Jan 15:1-11. doi: 10.1080/24733938.2026.2614450. Online ahead of print.
Authors: Laura McManus, Aidan J Brady, Valerio Antonini, Brendan Egan, Michael Scriney
Summary: Speed zone thresholds in women’s soccer are often based on thresholds derived from the men’s game. This study applied a data-mining approach to generate (a) team-based speed zone thresholds, and (b) individualised speed zone thresholds for elite female soccer players. Activity data from 47 elite club-level female soccer players was collected using multi-constellation global navigation satellite systems technology during 76 competitive matches between 2020 and 2021. The elbow method was used to identify the number of thresholds in the dataset, and spectral clustering was applied to each player’s instantaneous match-play speed data to determine the value of these thresholds. Team-based categories were then formed by calculating the mean value of each threshold from the individual players. Three speed zone thresholds were identified (1.12, 2.83, and 5.10 m·s-1). The newly-generated speed zone thresholds resulted in greater distance covered in the top three speed zones (all p < 0.05) compared to existing speed zone thresholds for women’s and men’s soccer. The between-player coefficient of variation for individualised speed zone thresholds was 13.0% for the lowest threshold, 12.9% for the middle threshold, and 8.5% for the highest threshold. Average maximum match-play running speed was a significant predictor of all individualised speed zone thresholds (lowest threshold: β = 0.13, p = 0.016; middle threshold: β = 0.44, p = 0.001; highest threshold: β = 0.74, p < 0.001). This study demonstrates a data-mining approach to establish team-based and individualised speed zone thresholds for women’s soccer that could be applied within practical and academic settings.
2 Effects of plyometric jump training on measures of physical fitness and lower-limb asymmetries in male soccer players according to maturity: A randomized controlled trial
Reference: PLoS One. 2026 Jan 15;21(1):e0340863. doi:10.1371/journal.pone.0340863. eCollection 2026.
Authors: Nizar Bouafif, Roland van den Tillaar, Abdelkader Mahmoudi, Anis Chaouachi, Raouf Hammami
Download link: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0340863
Summary: The purpose of this study was to determine the effects plyometrics on dynamic balance, muscle power and lower limb asymmetries in youth soccer players according to maturity. 43 youth soccer players (23 pre pubertal and 20 post pubertal) were classified according to their peak height velocity (PHV) and participated in a 8-week progressive plyometrics training program or an active control with two weekly sessions, alongside three regular soccer-specific training sessions per week. Participants‘ training and performance caliber was rated Tier 2. While plyometrics training groups performed jumping and hopping exercises such as maximal and submaximal hopping on stable ground, active control groups performing passing skills. Pre and post training, tests included the Y balance test, single leg hop and 505 change-of-direction speed (CoD) tests; and lower limb asymmetries were calculated based upon these tests. The main findings were that plyometrics significantly improved these physical attributes, with greater enhancements observed in the post-Peak Height Velocity (PHV) group compared to both the pre-PHV group and the active control group. However, asymmetry did not improve after the training intervention and even increased for balance test in the post-PHV training groups compared with the pre-PHV groups at the post test. Plyometrics effectively enhances jumps, CoD and dynamic balance, with greater benefits observed in post- PHV male soccer players. While overall lower-limb asymmetry largely remained unchanged, a notable finding was an increase in balance asymmetry specifically within the post-PHV group, attributed to a differential enhancement of left and right limb balance.
3 The Effects of a Soccer-Specific and Traditional Proprioceptive Training Programs on Change of Direction, Passing Skills, and Balance in Young Soccer Players
Reference: J Strength Cond Res. 2026 Jan 14. doi: 10.1519/JSC.0000000000005317. Online ahead of print.
Authors: Branislav Majkić, Nikola Stojanović, Doroteja Rančić, Aleksandra Aleksić
Summary: The main goal of this research was to evaluate the effects of soccer-specific proprioceptive training (SSP), traditional proprioceptive training (TP), and control group (CG) in trained or developmental young soccer players. Fifty-four subjects (aged 10–12 years) were randomly allocated to one of these 3 groups and underwent 10 weeks of training, with pre-intervention and post-intervention assessments. Tests included Slalom and Zig-Zag tests (with and without a ball), Loughborough Passing Test (LPT), and Balance Error Scoring System (BESS). Changes in performance were analyzed using repeated-measures ANOVA with Bonferroni post hoc and difference-in-differences analysis, effect sizes (Hedge’s g) and 95% confidence interval (95% CI). Significant Time × Group interactions were found for the Slalom (p = 0.029, = 0.129), Slalom with ball (p = 0.017, = 0.148), LPT total (p = 0.032, = 0.127), and BESS (p = 0.019, = 0.144). Furthermore, SSP exhibited greater improvements compared with CG in Slalom (g = 1.37, 95% CI [0.36–2.37]; large), Slalom with ball (g = 0.40, 95% CI [0.13–0.67]; small), LPT total time (g = 0.90, 95% CI [0.24–1.56]; moderate), and BESS (g = 0.93, 95% CI [0.19–1.67]; moderate). In addition, TP showed larger gains compared with CG in BESS (g = 0.94, 95% CI [0.20–1.69]; moderate), whereas all other between-group differences were trivial to small, indicating no clear differences. Soccer-specific proprioceptive and TP should be prioritized in youth programs because it may offer advantages over regular soccer training in enhancing change of direction, passing skills, and balance.
4 Is Quality of Life a Reason Related to the Retirement of Professional Male Soccer Players?
Reference: Transl Sports Med. 2025 Dec 11:2025:3376033. doi: 10.1155/tsm2/3376033. eCollection 2025.
Authors: Masar Gjaka, Kaltrina Feka, Abbey Thomas, Harald Tschan, Antonio Tessitore
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12782323/pdf/TSM2-2025-3376033.pdf
Summar: Limited knowledge exists regarding how retirement from a professional soccer career may influence players‘ future quality of life and overall health status. This study aimed to explore the reasons for ending professional soccer careers and to examine the postretirement health and quality of life among former soccer players in Kosovo. Seventy-three retired male professional soccer players from Kosovo participated in this cross-sectional study with a retrospective design. The participants completed a questionnaire covering demographics, career details, reasons for retiring, history of soccer-related injuries, current health and activity status, and psychological aspects associated with their professional careers and retirement. Players were divided into two groups: medical retirees (MRs) and nonmedical retirees (NMRs). The Mann-Whitney U test was used to compare continuous data between the two groups, and cross-tabulation methods were employed for categorical data. Nonmedical reasons were the main cause of retirement among Kosovar soccer players (p < 0.001), with job-related issues (58.8%) as the main retirement reason. The NMR group retired later and had longer careers than the MR group, though this was not statistically significant. Lower extremity injuries, particularly ankle and knee injuries, were the most prevalent among all players. After retirement, the NMR group engaged more in physical activity and continued playing soccer significantly more than the MR group (p < 0.001 and p = 0.021). The MR group reported significantly more pain (p < 0.001), analgesic use (p = 0.001), fear of career-ending injuries (p < 0.001), and depression symptoms during their careers (p < 0.001). Overall, NMR had significantly better quality of life and health status than MR (p < 0.001 and p < 0.001, respectively). This study highlights the impact of retirement reasons on the long-term health and quality of life of soccer players in Kosovo. It calls for enhanced support systems to prepare athletes for life after soccer, mitigating negative health outcomes associated with forced retirement due to injuries.
5 The impact of after-school soccer exercises on inhibitory control function in children aged 8-11: an fNIRS study
Reference: BMC Pediatr. 2026 Jan 10. doi: 10.1186/s12887-025-06477-9. Online ahead of print.
Authors: Mingchao Xu, Siyi Sun, Xiaoke Zhong, Yingxu Pan, Wenwu Leng, Hanzhe Chen, Changhao Jiang
Download link: https://link.springer.com/content/pdf/10.1186/s12887-025-06477-9_reference.pdf
Summary: Inhibitory control, a crucial higher cognitive function, is closely associated with children’s daily routines and academic performance. After-school physical activities serve as a fundamental avenue for children to participate in sports and also play a pivotal role in enhancing their cognitive development, thereby significantly impacting their overall growth. This study aims to investigate the impact of 12 weeks of after-school soccer exercise on inhibitory control in children aged 8-11 years. Using a 2 × 2 mixed experimental design, 70 children aged 8-11 were randomly assigned to either an experimental or control group. The experimental group received 12 weeks of extracurricular soccer training, attending 60-minute sessions three times a week, while the control group maintained their regular lifestyle and study routine. To assess inhibitory control performance and prefrontal cortex activation levels, all participants completed the Flanker task, with prefrontal cortex oxygenation levels measured using functional near-infrared spectroscopy (fNIRS) during the task. Following the intervention, the experimental group demonstrated a significant increase in accuracy on the incongruent task compared to pre-intervention levels. Post-intervention, there was a notable improvement in accuracy on the Flanker task compared to pre-intervention levels, with no significant changes observed in the control group. Additionally, there was a significant increase in blood oxygen response in the right posterior frontal area (R-PFA) and the right dorsolateral prefrontal cortex (R-DLPFC) in the experimental group compared to pre-intervention levels, while no significant changes were observed in the control group. Pearson correlations indicated a significant association between activation in the R-PFA and R-DLPFC and improvements in accuracy resulting from post-intervention soccer training. Our research hypothesis is corroborated by the study findings, indicating that involvement in extracurricular physical exercise within a school environment may impact the inhibitory control function of children. It is suggested that the right prefrontal cortex may have a pivotal role in enhancing inhibitory control function through physical activity.
6 Isokinetic Strength and Functional Ratio for Quadriceps and Hamstrings among Semi-Professional Athletes in UAE playing Football, Cricket, and Tennis- Biomechanical Implications
Reference: F1000Res. 2025 Oct 24:14:1163. doi: 10.12688/f1000research.170911.1. eCollection 2025.
Authors: Yogi Bhatt, Animesh Hazari, Shashikumar Channmgere Govindappa, Praveen Kumar Kandakurti
Summary: This study aims to compare the isokinetic strength of the Hamstrings against the Quadriceps for Football, Cricket, and Tennis among semi-professional athletes. An observational, cross-sectional study was conducted with the inclusion of participants between 18-40 years, both males and females having an active athlete profile playing Football, Cricket, and Tennis as semi-professional (competing in inter-collegiate, national-level tournaments in the UAE). The minimum duration for each sport was one hour per day and three to five times per week. A total of 66 participants were enrolled, with 22 participants in each group. The ISOMOVE isokinetic device was used to assess the strength of dynamically contracting Quadriceps concentrically against eccentric contraction of the Hamstring muscles to determine the functional ratio (H/Q ratio). Age-wise distribution of players showed predominant male participants with 77.3% of players in Football, 68.2% in Cricket, and 59.1% in Tennis. The comparison for the mean peaks of isokinetic strength for functional ratio suggested a statistically significant difference between the three sports (Football p<0.001, Cricket p=0.006, Tennis p =0.003). The findings suggested that the highest H/Q ratio was found in Football players with a mean value of 0.51±0.07, followed by Cricket and Tennis with a mean of 0.48±0.08 and 0.42±0.05, respectively (p<0.05). The isokinetic strength testing for H/Q ratio was found to be higher in Football players, followed by Cricket and Tennis players for semi-professional athletes. The study concluded that the functional H/Q ratio varies between three similar sports as the demand on the target muscle would specifically vary. Thus, semi-professional players who play multiple games should consider enhancing FR for the Hamstring to the Quadriceps, besides the strength and training specific to sports, to avoid the risk of injuries.
7 Risk Analysis between Hip Strength with Hamstring Injuries among Professional Youth Footballers in a Single Malaysian Football Club
Reference: Malays Orthop J. 2025 Nov;19(3):10-18. doi: 10.5704/MOJ.2511.002.
Authors: M Azwan-Aziz, M Y Yunus, A H Ahmad-Shushami
Summary: There is paucity of research regarding the incidence of hamstring injuries and its inherent causes within youth Malaysian football contexts. We aim to investigate the incidence of hamstring injuries among youth footballers and analyse the risk between intrinsic risk variables (anthropometric and hip strength) and the risk of hamstring strain injuries (HSI). This was a prospective cohort study involving 72 youth Malaysian professional footballers from a single prestigious club. This study was conducted during the 2023 Malaysian football league. Pre-season medical evaluations encompassed demographic information, anthropometric measurements, and isometric strength examinations of the hamstrings, quadriceps, hip abductors, and hip adductors. Injury surveillance was conducted during the season. The incidence of HSI in this study was 0.331 injuries per 1000 H, with incidence of injury during match higher 2.79 injuries per 1000 H compared to training 0.216 injuries per 1000 H. There was no hamstring injuries reported in U20. Forty-one (56.9%) has hamstring to quadriceps (H:Q) ratio <0.6 and forty-six (63.9%) has hip abductor to adductor ratio <0.8. The binary logistic regression analysis revealed increasing age (OR: 1.227, CI: 0.98 – 5.03), increased body mass index (OR: 1.79, CI: 0.415 – 7.77), increased body fat mass (OR: 1.39, CI: 0.33 – 5.89), and low H:Q ratio (OR: 4.274, CI: 0.347 – 58.1), increase the risk of HSI. Injury prevention programs in youth footballers should incorporate these modifiable risk factors into account to reduce the risk of hamstring injuries.
8 The impact of warm-up intensity on lower-limb explosive power and agility in male university football athletes
Reference: BMC Sports Sci Med Rehabil. 2026 Jan 12. doi: 10.1186/s13102-025-01524-5. Online ahead of print.
Authors: Liangzhu Feng, Hongyou Liu
Download link: https://link.springer.com/content/pdf/10.1186/s13102-025-01524-5_reference.pdf
Summary: Warm-up intensity is considered a key factor influencing acute physical performance, yet its specific effects on explosive power and agility in university football players remain unclear. This study compared the acute effects of low-, moderate-, and high-intensity warm-up on lower-limb explosive power and agility. Twenty male university football athletes completed three 15-min warm-up protocols differing in intensity. Performance was assessed using the standing triple jump (STJ), 10 m sprint, 505 test, and T-test at pre-, post-, and post-10. Generalized mixed linear models were applied to evaluate the effects of intensity and time, with results reported as standardized effect sizes (ES) and 90% confidence limits (CL). The 10 m sprint performance was substantially better after the low-intensity warm-up than the moderate-intensity (ES; ± 90% CL: Post: 1.93; ± 0.64; Post-10: 3.31; ± 0.45) and high-intensity (Post: 1.90; ± 0.64; Post-10: 3.56; ± 0.65) warm-ups. The 505 test also showed superior performance after the low-intensity warm-up (vs. moderate: 1.55; ± 0.74, 1.16; ± 0.44; vs. high: 3.15; ± 0.72, 1.24; ± 0.44). Notably, in the 505 test (post: 1.6; ± 0.7; post-10: trivial), performance following the moderate-intensity warm-up at post was also substantially superior to that following the high-intensity warm-up. The T-test demonstrated a similar advantage (vs. moderate: 0.95; ± 0.23, 0.78; ± 0.22; vs. high: 0.86; ± 0.23, 0.73; ± 0.22). In contrast, the STJ (vs. low, post: 0.66; ± 0.31; post-10: 0.51; ± 0.31) improved only immediately after the moderate- and high-intensity warm-ups. Low-intensity warm-up produced the most consistent and sustained improvements in sprint and agility performance. Moderate-intensity warm-up showed only a brief advantage in the 505 test, whereas high-intensity warm-up generally impaired speed and change-of-direction performance, with any explosive power gains being short-lived. These findings identify warm-up intensity as a key determinant of pre-competition readiness in male university football athletes.
9 Hamstring Training and Football Performance: A Systematic Review and Meta-Analysis
Reference: Int J Sports Med. 2026 Jan 12. doi: 10.1055/a-2785-7739. Online ahead of print.
Authors: Antonio Riego Ruiz, Darío Martínez-García, Ignacio Jesus Chirosa, Luis Javier Chirosa, Guido Edgardo Contreras Díaz, Daniel Jerez-Mayorga
Summary: The aim of this review was to evaluate the impact of strength training on hamstring muscle strength and physical performance in football players.A systematic review was conducted following the PRISMA guidelines, and the protocol was registered in PROSPERO.A literature search was performed using four electronic databases: Web of Science, SCOPUS, SportDiscuss, and PubMed.Randomized controlled trials conducted with football players aged 15 years or older were included.The studies were grouped according to moderating variables such as training protocol and physical performance outcomes. A total of 20 studies met the inclusion criteria for the review, with 10 studies included in the meta-analysis. Strength training programs demonstrated moderate to large effects on both concentric and eccentric strength of the hamstrings and quadriceps, as well as on physical performance measures such as jumping and sprinting. Eccentric overload training produced the most significant benefits in sprint and jump performance. Strength training, particularly eccentric training, significantly improves both hamstring muscle strength and physical performance in football players of male football players aged 15 years and older, highlighting its importance for injury prevention and sports performance enhancement.However, additional research is needed to evaluate whether similar benefits can be observed in female players and younger age groups.
10 Normative visual performance standards in male professional football players: a comprehensive assessment of visual acuity, binocular function, and visuo-cognitive abilities
Reference: Clin Exp Optom. 2026 Jan 12:1-9. doi: 10.1080/08164622.2025.2610973. Online ahead of print.
Authors: Jorge Jorge, Rui Fuste, Rui Sousa
Summary: Visual performance plays a fundamental role in sports, contributing to decision-making, spatial awareness, and object tracking. Establishing normative values for key visual functions supports performance assessment and training optimisation in athletes. This study aimed to evaluate visual acuity, refractive error, binocular function, and Visuo-cognitive abilities in professional football players to establish normative visual performance standards across different levels of athletic ability. Visual assessments included static and dynamic visual acuity, refractive error, binocular vision (phoria, fusional vergence, vergence facility, and accommodative facility), and stereopsis. Visuo-cognitive abilities, such as multiple object tracking, reaction time, and peripheral perception, were also evaluated. The results were classified into five performance levels: Elite (10th percentile), Proficient (25th percentile), Average (50th percentile), Insufficient (75th percentile), and Dysfunctional (90th percentile). Statistical analyses were performed to determine normative thresholds and identify significant differences across these performance levels. A total of 262 male professional football players (mean age 24.6 ± 4.8 years) were assessed. Visual acuity averaged 1.09 ± 0.20, with Elite-level performance at 1.26 (6/4.8) and Dysfunctional-level at 0.90 (6/6.7). Dynamic visual acuity was 0.72 ± 0.17, with thresholds at 0.62 (6/9.5) (insufficient) and 0.52 (6/11.5) (Dysfunctional). Refractive error showed minimal anisometropia (0.20 ± 0.41D). Phoria status was orthophoric at distance (0.0 ± 2.1Δ) and exophoric at near (2.2 ± 4.7Δ). Accommodative facility averaged 11.7 ± 4.6 cpm. Stereopsis at distance averaged 1.85 ± 0.16 log arcsec, with Elite performance at 1.78 log arcsec and Dysfunctional at 2.00 log arcsec. Peripheral span averaged 40.7 ± 11.9, while multiple objects tracking and visual reaction time averaged 1623.3 ± 430.5 ms and 327.4 ± 37.8 ms, respectively. Normative visual data is provided for male professional football players, including visual acuity, binocular vision parameters, and visuo-cognitive skills, offering a reference for assessing and optimising performance in football.
11 Positional and Temporal Intermittency in Football: A Metabolic Model Approach
Reference: Int J Sports Med. 2026 Jan 10. doi: 10.1055/a-2785-7601. Online ahead of print.
Authors: Norbert Callau-Arbo, Albert Altarriba-Bartes, Antonio Alonso-Callejo, David Pajon, Jose Luis Felipe, Demetrio Lozano
Summary: This study examined positional differences in the intermittent nature of efforts during professional football matches and compared two analytical models: one using a fixed metabolic power threshold (Pmet20) and another based on the relationship between oxygen consumption and metabolic power (VO₂-Pmet). Data were collected from 24 First Division players in Cyprus across 50 matches during the 2022-2023 season using GPS technology (WIMU Pro System). High and low metabolic load efforts (HMLE and LMLE) were analyzed. Results showed significant positional differences in both the duration and intensity of HMLE and LMLE. Compared to the Pmet20 model, the VO₂-Pmet method identified approximately twice longer HMLE durations (≈4.1 vs. 2.1 s) and about 70-150% more detected efforts across positions, together with shorter recovery intervals. A notable decline in LMLE intensity between halves was linked to reduced performance. These findings highlight the dynamic interplay between aerobic and anaerobic systems in football and emphasize the need for position-specific training. Practical applications include designing training programs that reflect the unique intermittent demands of each position, focusing on both high-intensity efforts and recovery. This study provides a robust framework for understanding football’s intermittent nature and offers actionable strategies to enhance player performance through tailored conditioning.
12 How many trials are enough? Familiarization requirements in the Loughborough Soccer Passing Test
Reference: BMC Sports Sci Med Rehabil. 2026 Jan 22. doi: 10.1186/s13102-026-01538-7. Online ahead of print.
Authors: Burak Çağlar Yaşlı, Raci Karayiğit, Aysberg Şamil Önlü, Özcan Esen, Gabriel Mareș, Dan Iulian Alexe, Gabriel Stănică Lupu, Cristina Ioana Alexe
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01538-7_reference.pdf
Summary: The Loughborough Soccer Passing Test (LSPT) has proven to be a valid and reliable method for assessing soccer skill performance. However, there are various preparation protocols that exist for the LSPT. The aim of this study is to determine how many trials are required to gather reliable data during LSPT familiarisation. 81 subelite male youths (12.70 ± 2.67 years; 158.32 ± 17.21 cm; 49.01 ± 14.19 kg) and 17 professional female soccer players (21.47 ± 2.37 years; 164.70 ± 5.00 cm; 57.11 ± 4.27 kg) participated in the study. Following a brief explanation, the participants underwent five repetitions of the LSPT, after which differences between trials were analysed using mixed ANOVA for original time, penalty time, and performance time of LSPT. Adjusted residual values and the Smallest Worthwhile Change (SWC) approach were employed to assess the distributions across repetitions and the practical significance of the observed differences. Mixed-repeated measures ANOVA showed that Trial 1 significantly underperformed relative to the subsequent four trials across all LSPT values (p < 0.05). There were no statistical differences observed within other trials. Considerable improvement was noted solely between the first trials and subsequent attempts; exceeding the smallest worthwhile change (SWC) thresholds of 1.38 sec, 2.29 sec, and 3.36 sec for original time, penalty time, and total performance time, respectively. Performance time enhanced by 5% between first two trials, however strength of acquisitions remain inconsistent and negligible subsequent trials. A single trial primarily diminishes the learning effect in LSPT preparation, especially in young sub-elite athletes and professional female athletes. In particular, in situations where samples are large or testing time is limited, implementing a single familiarisation trial seems a practical and efficient option. At the same time, given the higher variability of penalty time, specialists can consider adapting the number of trials depending on the testing objectives. This finding has applicative value for coaches, physical trainers and researchers, as it allows them to reduce the time and resources required for the testing protocol without compromising the validity and reproducibility of the results.
13 On the relationship between external and internal load variables in elite youth soccer players
Reference: Sci Rep. 2026 Jan 22;16(1):2858. doi: 10.1038/s41598-025-31487-z.
Authors: Nils Haller, Thomas Stanin, Tilmann Strepp, Julia Blumkaitis, Manfred Düring, Thomas Mroz, Wolfgang Trutschnig, Thomas Leonhard Stöggl
Download link: https://www.nature.com/articles/s41598-025-31487-z.pdf
Summary: The study investigated the relationship between external and internal training load measures in 25 male elite youth soccer players (age: 16.6 ± 0.9 years, VO2max: 59 ± 4 ml/min/kg) over 3 months. External load (i.e., total distance, high metabolic power distance, high-speed running) was quantified using a local positioning system and related to subjective (RPE, sleep quality, drive (energy level)), biochemical (creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP), urea, cortisol, transferrin), and neuromuscular (CMJ) markers. Single day workload (1DL), exponential 7-day workload (7DL), and the acute: chronic workload ratio (ACWR) were calculated. 1DL parameters were correlated (Spearman’s rho) with RPE (range r = 0.24 to 0.43, p < 0.01) and 1DL distance was negatively related to drive (r = – 0.28, p < 0.001). LDH correlated positively with training load across all calculation methods (up to r = 0.27, p < 0.01). CK exhibited positive correlations to ACWR training load (r = 0.23 to 0.27, p < 0.05), while transferrin (ACWR) and CRP (1DL) showed negative associations to training load (r = – 0.21 to – 0.28, p < 0.05). CMJ eccentric mean force was negatively correlated with all ACWR training load variables (r = – 0.22 to – 0.25, p < 0.01). In summary, subjective measures showed stronger and more consistent associations with training load than biomarkers or neuromuscular testing. Practitioners may confidently use well-structured questionnaires for load monitoring in elite youth soccer.
14 Epidemiology of Sport Injury Among Korean Male Youth Soccer Players: A Prospective Cohort Study
Reference: Pediatr Exerc Sci. 2026 Jan 19:1-7. doi: 10.1123/pes.2024-0118. Online ahead of print.
Authors: Inje Lee, Sunghe Ha, Hyung Gyu Jeon, Sae Yong Lee
Summary: This study aimed to identify the injury profiles of Korean youth soccer players over a 1-year period. One hundred Korean male soccer players aged 12-15 years were recruited for this prospective epidemiological study. Data on injury characteristics, including the type of field, severity of injuries, time to return to full soccer activities, re-injury rate, and surgery rate were collected by the medical staff. The incidence rate of injuries including body locations, types, and causes was calculated as the number of injuries per 1000 hours. In total, 140 injuries were reported during the 1-year follow-up. The overall incidence rate was 5.76 per 1000 hours. The incidence rate was higher during matches than during training (14.76 per 1000 h vs 3.88 per 1000 h). The most common body location, type of injury, and cause of injuries were the ankle (n = 46, 32.9%), ligament sprain (n = 54, 37.1%), and noncontact injury (n = 63, 45.0%), respectively. Prevention strategies should focus on noncontact ankle sprains in Korean youth soccer players. Given the growth spurts experienced by U-15 soccer players, emphasis should be placed on muscle conditioning and balance training to control movement and prevent soccer injuries.
15 Sport specialization, injury and illness: a prospective study of elite female adolescent soccer players
Reference: J Sports Med Phys Fitness. 2026 Jan 22. doi: 10.23736/S0022-4707.25.17535-X. Online ahead of print.
Authors: Andrew Watson, Kristin Haraldsdottir
Summary: Although cross-sectional evidence exists regarding the association between sport specialization and health outcomes, sport-specific, prospective research is lacking. The aim of this study was to determine the relationship between sport specialization status and in-season injury and illness risk in elite female adolescent soccer players. 80 female youth soccer players (ages 13-18) from a local youth soccer organization underwent preseason evaluation of maximal aerobic capacity (VO2max) and sport specialization and provided self-reporting of daily training load (session-rating of perceived exertion), injury and illness for two four-month competitive soccer seasons. Mixed effects logistic regression models were used to predict individual injury and illness (yes/no) during the study period, using sport specialization, age, and training load as fixed effects and individual athlete as a random effect. Specialized (N.=46) athletes did not differ from non-specialized (N.=34) athletes with respect to age, preseason physical activity, VO2max or in-season training load (all P>0.05). 28 athletes participated in both years, representing 108 player-years. No differences were seen in the proportion of individuals from each group that reported an in-season injury (specialized = 25% vs. 20%, P=0.55) or illness (46% v 38%, P=0.41). After adjusting for age and training load, individual injuries (OR=0.86 [0.26, 2.8], P=0.81) and illnesses were not significantly predicted by specialization (OR=1.06 [0.45, 2.5], P=0.89). After adjusting for age and training load, late sport specialization was not associated with in-season injury or illness risk in elite female soccer players.
16 Lateral extra-articular tenodesis does not affect tibiofemoral axial rotation in primary ACL reconstruction in professional soccer players
Reference: Knee Surg Sports Traumatol Arthrosc. 2026 Jan 21. doi: 10.1002/ksa.70283. Online ahead of print.
Authors: Jakob Ackermann, Mary Jones, Simon V Ball, Adnan S Kabeer, Prashant Bamania, Christopher Watura, Justin C Lee, Andy Williams
Summary: Increased tibiofemoral (TF) rotation has been linked to a higher risk of graft failure following anterior cruciate ligament reconstruction (ACLR). This study evaluated whether isolated ACLR or the addition of lateral extra-articular tenodesis (LET) influences TF rotation in professional soccer players. A retrospective review was conducted on professional soccer players who underwent ACLR between January 2012 and August 2024. Inclusion criteria were primary ACL injury and availability of pre- and postoperative magnetic resonance imaging (MRI). Players were grouped based on whether LET was performed in addition to ACLR, thus forming two groups who either underwent ACLR or ACLR + LET. Demographic and anatomical variables, including age, medial and lateral posterior tibial slope (PTS), knee flexion during MRI, tibial tubercle-trochlear groove (TTTG) distance, and TF rotation, were compared. A subgroup analysis was performed in players with available pre-injury MRI, allowing assessment across three time points: pre-injury, preoperative, and postoperative. Statistical analyses included appropriate parametric and nonparametric tests for group comparisons, repeated measures, and reliability assessment, with significance set at p < 0.05. Ninety-eight professional soccer players (mean age 23.2 ± 4.2 years) were included, of whom 70 (71.4%) underwent concomitant LET. Preoperatively, groups did not differ in age, medial or lateral PTS, knee flexion, TTTG distance, or TF rotation (all p > 0.05). Across all players, TF axial rotation did not change significantly from pre- to postoperative imaging (6.3 ± 6.0° vs. 6.3 ± 5.8°, p = 0.876). TTTG distance increased from 8.7 mm to 9.4 mm (p = 0.026), and knees were slightly more extended postoperatively (18.2° ± 5.8 vs. 16.4° ± 6.1, p = 0.006). No significant differences in delta values for knee flexion, TTTG, or TF rotation were observed between ACLR and ACLR + LET groups (all p > 0.05). In 16 players with MRI at all three time points, no significant changes in TTTG or TF rotation occurred (both p > 0.05). Resting TF rotation remained unchanged after ACLR, regardless of LET augmentation, suggesting LET does not modify baseline rotational alignment in professional soccer players.
17 High return to play but low return to preinjury level after anterior cruciate ligament reconstruction in soccer players: A systematic review with meta-analysis
Reference: Knee Surg Sports Traumatol Arthrosc. 2026 Jan 21. doi: 10.1002/ksa.70274. Online ahead of print.
Authors: Weipeng Liu, Zhiyuan Tan, Weichao Li, Zhiyuan Qin, Peter Krustrup, Wenhua Li
Summary: This systematic review with meta-analysis aimed to quantify return to play (RTP) outcomes in soccer players after anterior cruciate ligament reconstruction (ACLR), including the rate of RTP, time to RTP, rate of return to preinjury level of sport, and secondary ACL injury. Additionally, the meta-analysis sought to explore the impact of sex and competitive level on RTP outcomes. Five databases were searched to identify studies including soccer players who underwent ACLR and that evaluated RTP outcomes. Outcomes included the rate of RTP, time to RTP, rate of return to preinjury level of sport and secondary ACL injury. Data were transformed using Freeman-Tukey double arcsine and analyzed with a random-effects model to calculate pooled rates and 95% confidence intervals (CIs). Subgroup analyses were conducted based on sex and competitive level. Thirty-nine studies with 7452 players were included. The pooled RTP rate was 83% (95% CI, 77%-89%), while 60% (95% CI, 49%-71%) returned to preinjury level. Mean time to RTP was 9.1 months (95% CI, 8.2-10.1). The secondary ACL injury rate was 15% (95% CI, 12%-19%), with 9% ipsilateral and 10% contralateral. Subgroup analyses showed significantly higher RTP rates in males (86%) and elite athletes (93%) than in females (72%) and non-elite athletes (64%), while secondary ACL injuries were more frequent in females (20%) and non-elite athletes (22%) than in males (13%) and elite athletes (12%). Most soccer players returned to any level of play within 9.1 months after ACLR. However, only three in five players returned to their preinjury levels. Furthermore, the secondary ACL injury rate was high, with 15% of soccer players sustaining either ipsilateral or contralateral ACL re-injuries. These findings highlight the need for tailored rehabilitation programs and strict RTP criteria to facilitate return to preinjury level and prevent secondary ACL injury.
18 Mechanisms, Injury Patterns and Biomechanical Factors of Anterior Cruciate Ligament Injuries in Football (Soccer): A Systematic Review and Meta-Analysis of Video-Analysis Studies
Reference: Sports Med. 2026 Jan 22. doi: 10.1007/s40279-025-02345-9. Online ahead of print.
Authors: Aaron Miralles-Iborra, Francisco J Vera-Garcia, Jose L L Elvira, Juan Del Coso, Matthew Buckthorpe, Manuel Manchón-Davó, Heidy Rondón-Espinosa, Javier De Los Ríos-Calonge, Víctor Moreno-Pérez
Download link: https://link.springer.com/content/pdf/10.1007/s40279-025-02345-9.pdf
Summary: To date, several studies have characterised the mechanisms, injury patterns and biomechanical factors leading to anterior cruciate ligament (ACL) injuries in football (soccer). However, varying methodologies have resulted in differing findings and outcomes. We aimed to provide a clearer understanding of the mechanisms, injury patterns and biomechanical factors that may pose a higher risk of ACL injury in football players, we conducted a meta-analysis of studies that used video analysis as their primary research tool. Five databases (PubMed, Web of Science, Embase, Scopus and SPORTDiscus) were searched from inception to September 2024 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The population, exposure and outcome framework were used to formulate eligibility criteria. Cohort studies of male and female football players reporting mechanisms, injury patterns and/or biomechanical factors of ACL injury examined by video analysis were included. A subsequent meta-analysis was performed to calculate odds ratios (ORs) and frequencies for the different patterns leading to ACL injury. Thirteen studies published between 2015 and 2024 were included with a total of 709 participants. Ten studies focused on male players, two on female players and one study included both. Regarding mechanisms, non-contact ACL injuries were more likely than direct contact (OR = 5.75, 95% confidence interval [CI] 2.28-14.53, p < 0.001, I2 = 88%) and indirect contact (OR = 3.32, 95% CI 1.88-5.86, p < 0.001, I2 = 74%). Anterior cruciate ligament injuries were more common during defending actions compared with attacking actions (OR = 2.51, 95% CI = 1.23-5.08, p < 0.001, I2 = 88%) and without ball possession than with ball possession (OR = 2.31, 95% CI 1.01-5.29, p = 0.05, I2 = 75%). Particularly, the frequency of ACL injuries while pressing/tackling was significantly higher than the rest of the actions (p < 0.001). Regarding biomechanical factors, ACL injuries were more common when players were on single-leg support compared with double-leg support (OR = 9.66, 95% CI 6.97-13.39, p < 0.001, I2 = 0%). Anterior cruciate ligament injuries often involved complex multiplanar interactions, with a predominance of knee flexion (range from 26° ± 10° at initial contact to 39 ± 11° at the injury frame) along with a consistent knee valgus pattern at the injury frame (79% of the cases; χ2 = 33.32, p < 0.001). A comprehensive review of video-analysis studies on ACL injuries in football reveals that the most common injury pattern involves a defending action performed on single-leg support, without ball possession, and occurring through a non-contact mechanism. Still, the review reflects that the mechanism of ACL injury in football is complex and should be interpreted holistically rather than in isolation.
19 Drawing and Soccer Tactical Memorization: An Eye-Tracking Investigation of the Moderating Role of Visuospatial Abilities and Expertise
Reference: Vision (Basel). 2026 Jan 1;10(1):2. doi: 10.3390/vision10010002.
Authors: Sabrine Tlili, Hatem Ben Mahfoudh, Bachir Zoudji
Download link: https://www.mdpi.com/2411-5150/10/1/2
Summary: Dynamic drawing has emerged as a strategy to communicate tactical diagrams, yet its effectiveness remains uncertain and appears to depend on individual differences. This study investigated how the memorization and visual processing of tactical soccer scenes are influenced by drawing format (static drawing vs. dynamic drawing) and moderated by visuospatial abilities (VSA) and expertise. Expert (N = 57) and novice (N = 54) participants were randomly assigned to one of two conditions. In the static drawing condition, participants viewed a pre-drawn, completed tactical diagram accompanied by an oral explanation. In the dynamic drawing condition, they observed the coach drawing the diagram in real time while delivering the same explanation. VSA was first assessed using a control test. Then, in the main test, participants memorized and reproduced the tactical scene while their eye movements were recorded using an eye tracker. Key findings revealed a three-way interaction, highlighting the occurrence of an expertise reversal effect: high VSA novices performed better with dynamic drawing, whereas low VSA experts benefited more from static drawing, showing distinct visual processing patterns across groups. Overall, the results highlight the need to tailor drawing strategies to individual characteristics, particularly VSA and expertise, to optimize visual attention and tactical memorization.
20 A qualitative study of goalkeeper coaches‘ perceptions of key qualities in talented youth soccer goalkeepers
Reference: J Sports Med Phys Fitness. 2026 Jan 20. doi: 10.23736/S0022-4707.25.17208-3. Online ahead of print.
Authors: Walter Steenbok, Alliance Kubayi, Heather Morris-Eyton, Joseph A Stone
Summary: Despite a substantial body of literature on identifying talent in outfield players, information on goalkeepers (GKs) is scarce due to the specialist demands associated with the position. The purpose of this study was to explore which qualities GK coaches perceive as important for talented youth soccer GKs. This qualitative study used a pragmatic research paradigm. The sample consisted of eight GK coaches (mean age 50.12±9.33 years; mean experience 17.25±9.97 years) who were purposively recruited to participate in the study. A semi-structured interview guide was used to collect data, and a two-stage thematic analysis was employed to identify themes. Four themes and 10 sub-themes were constructed: technical (i.e. handling), physical (i.e. upper body strength and height), tactical (defensive organization, build-up play and decision-making) and psychosocial (i.e. bravery, coachability, communication and composure) attributes. These findings may provide coaches with valuable information regarding the traits that potentially talented GKs should possess, which could guide training for talent development programs to increase their chances of being chosen for future opportunities.