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 Impact of Injury on Anxiety, Depression, and Quality of Life in Youth Soccer Players

Reference: Clin J Sport Med. 2026 Jan 5. doi: 10.1097/JSM.0000000000001401. Online ahead of print.
Authors: Ian Staresinic, Kristin Haraldsdottir, Jennifer Sanfilippo-Nackers, Sakar Gupta, Quinn Steiner, Scott Anderson, Andrew Watson
Summary: The purpose of this cross-sectional study was to evaluate associations among injury, quality of life (QOL), and mental health among elite youth soccer athletes. Study materials were sent to Elite Clubs National League (ECNL) clubs through an online survey link. Soccer athletes were invited to participate in May and June of 2024 by their respective clubs. Six hundred sixty-eight ECNL soccer athletes (ages 13-19 years) completed the study. Injury history and risk factors were assessed using a demographic survey. Outcomes including QOL (Pediatric Quality of Life Inventory), anxiety (General Anxiety Disorder-7), and depression (Patient Health Questionnaire-9) were compared between athletes by injury status (uninjured, recovered, injured) using Tukey-adjusted pairwise comparisons of estimated marginal means. Two hundred ninety-five (44.2%) respondents reported an injury in the prior 6 months, of whom 224 (33.5%) had recovered, and 71 (10.6%) were currently injured. Uninjured athletes reported significantly lower symptoms of anxiety (5.0, 95% CI [4.5-5.5]) than currently injured (6.6 [5.5-7.7], P = 0.008) and recovered athletes (6.0 [5.3-6.6], P < 0.001). Currently injured athletes reported higher levels of depression (6.9 [5.8-8.1]) than recovered (5.2 [4.5-5.8], P = 0.01) and uninjured athletes (4.6 [4.0-5.1], P < 0.001), while the difference between recovered and uninjured athletes was not statistically significant (P = 0.19). Uninjured athletes also demonstrated significantly higher total QOL (81 [80-82]) than recovered (79 [77-80], P = 0.021) and currently injured (73 [70-76], P < 0.001) athletes. Injured youth soccer athletes report worse mental health and QOL than uninjured athletes, even after return to play. Stakeholders in youth sports should consider that negative psychosocial impacts of injury may persist beyond physical impacts.

2 Final whistle or beyond? Temporal dynamics of anxiety and psychological recovery in women’s soccer

Reference: Front Psychol. 2025 Dec 18:16:1697362. doi: 10.3389/fpsyg.2025.1697362. eCollection 2025.
Authors: Buse Sulu, Şeval Kayğusuz, Erdem Çakaloğlu
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12756479/pdf/fpsyg-16-1697362.pdf
Summary: Anxiety and emotions have been identified as fundamental determinants of psychological recovery. While positive emotions and self-confidence facilitate athletes‘ ability to regain balance and recover psychologically in the face of challenges, negative emotions together with cognitive and somatic anxiety may hinder this process. In this regard, it is important to examine psychological recovery in conjunction with anxiety and emotions to capture its dynamic nature. The aim of this study was to investigate the role of emotions and anxiety in athletes‘ psychological recovery and to evaluate their seasonal changes. The sample consisted of 20 female soccer players from Kastamonu Gücü Sports Club, competing in the Women’s 2nd League Group C in the 2023-2024 season. Analyses were conducted using R (version 4.4.1; R Core Team, 2024) with linear mixed-effects models (LMM). The models included both fixed effects and random intercepts for athletes. Analyses were performed with the lme4 and lmerTest packages, while model fit indices and explained variance were calculated using the MuMIn and performance packages; model assumptions were tested and VIF values were reported. The findings revealed that psychological recovery was supported by self-confidence and positive emotions, whereas cognitive/somatic anxiety, anticipated match difficulty, and negative emotions weakened it. In addition, a decline in recovery was observed as the season progressed. The models explained a large proportion of the variance in psychological recovery (R2m ≈ 0.60-0.65). The contribution of individual differences was limited (ICC ≈ 0.11-0.14), suggesting that shared seasonal processes were more influential than individual-level factors. In conclusion, psychological recovery is a dynamic process shaped by both protective (self-confidence, positive emotions) and risk-related (anxiety, anticipated match difficulty, negative emotions) factors. The seasonal decline underscores the importance of systematically integrating practices to support psychological recovery to sustain performance throughout the season.

3 Plyometric Performance in Under-10 Soccer Players: Effects of Modified Competitions and Maturational Status

Reference: Sensors (Basel). 2025 Dec 22;26(1):68. doi: 10.3390/s26010068.
Authors: Francisco Javier García-Angulo, Antonio García-Angulo, Ricardo André Birrento-Aguiar, Enrique Ortega-Toro
Download link: https://www.mdpi.com/1424-8220/26/1/68
Summary: The aim of this study was to examine the effects of different competition formats on the plyometric performance of under-10 soccer players, while analysing the influence of maturational status. A quasi-experimental design was applied, involving 50 players (mean age = 9.47 ± 0.54 years). Kinematic load was recorded using Wimu™ inertial accelerometers, and maturational status was evaluated using the percentage of predicted adult height (%PAH) as a moderating factor. Results indicate that while total impact volume did not show significant differences (p = 0.082), the modified format (MD1) showed a reduction in biomechanical intensity per action. Very large differences were reported in mean take-off acceleration (p = 0.001; BF10 = 23.97) and landing acceleration (p < 0.001; BF10 = 70.57). Furthermore, biological maturation was found to be an essential moderating factor, with a threshold of significance identified at 75.5% %PAH. The results of this study show that modified rules can be a good tool for modulating plyometric intensity without compromising the volume of exposure to the stimulus. These findings may highlight indicate the need to implement an individualized approach, based on maturational thresholds, to optimise adaptations and ensure joint safety during long-term development.

4 Epidemiology of Anterior Cruciate Ligament Injuries in the Top 5 European Football (Soccer) Leagues

Reference: Orthop J Sports Med. 2026 Jan 6;14(1):23259671251400766. doi: 10.1177/23259671251400766. eCollection 2026 Jan.
Authors: David Ortiz-Sánchez, Alfredo Bravo-Sánchez, María Ramírez-delaCruz, Pablo Abián, Carlos García-Sánchez, Javier Abián-Vicén
Summary: The anterior cruciate ligament (ACL) is one of the most frequently injured structures in different sports, particularly football (soccer). Numerous studies have investigated the mechanisms and risk factors leading to ACL ruptures in this sport; however, most analyses have focused on individual leagues. It was hypothesized that pooling data from different football leagues would show that (1) most ACL ruptures occur in noncontact situations, predominantly during the defensive phase and within the initial minutes of play; (2) the number and incidence rate of injuries differ significantly across leagues; and (3) the number of injuries correlates with the team market value. An online database was accessed to collect data on ACL ruptures and player characteristics in the top 5 European football leagues between the 2018-2019 and 2023-2024 seasons. Player age, player position, moment of injury during the season and during the match (if applicable), and team market value were initially collected. Then, the video of the moment of injury of those players injured during official matches was searched to classify the injury mechanism. A total of 272 ACL ruptures were identified, 44.5% involving defenders. Most occurred within the first 15 minutes of play. The mean age of injured players was 25.8 ± 3.9 years. Among the 135 injuries for which video analysis was available, 84 (62.2%) occurred during defensive actions, 66 (48.9%) were classified as noncontact injuries, and 35 (33.3%) happened while pressing an opponent. Differences in the number of injuries (P = .066) and injury rate (P = .225) between leagues, as well as the correlation between team market value and number of injuries (P = .922), were not statistically significant. Most ACL ruptures occurred through noncontact mechanisms, typically during defensive actions, particularly while pressing an opponent. Most injuries affected defenders and took place within the first minutes of play, with a mean player age of 25.8 years. No significant differences were found in the number or rate of injuries between leagues, nor was any correlation observed between team market value and the number of injuries.

5 Observed events frequencies and associated factors among soccer players during the 2021 African Cup of Nations competition: A video-based exploratory analysis

Reference: F1000Res. 2025 Oct 31:13:392. doi: 10.12688/f1000research.148161.3. eCollection 2024.
Authors: Amr Chaabeni, Amine Kalai, Helmi Ben Saad, Yacine Zerguini, Montassar Tabben, Karim Chamari, Anis Jellad
Download link: https://f1000research.com/articles/13-392/v3?gtmKey=GTM-PCBS9JK&immUserUrl=https%3A%2F%2Ff1r-proxy.f1krdev.com%2Feditor%2Fmember%2Fshow%2F&otid=1bc074d1-3db4-47ed-9f80-df1a4a3f2ab4&s3BucketUrl=https%3A%2F%2Ff1000research-files.f1000.com&submissionUrl=%2Ffor-authors%2Fpublish-your-research&transcendEnv=cm&transcendId=ef49a3f1-d8c1-47d6-88fc-50e41130631f
Summary: Understanding the epidemiology of soccer injuries during specific international competitions is essential for customizing preventive strategies. Several studies have reported outcomes related to international competitions but, to the best of our knowledge, there has been no investigation into the injury patterns during any African Cup of Nations (AFCON) tournaments. This study aimed to analyze the observed events frequencies and their characteristics during the 2021 African Cup of Nations (AFCON), which took place in Cameroon from January 9 to February 6, 2022. A video-based analysis covering 52 matches was conducted by two independent consultant physicians. They reviewed „observed events“ replays to determine frequencies and characteristics ( i.e. ; mechanisms, body location, match moment, player substitution, absence in the next match, and referee decisions). The tournament involved 519 male players, comprising 275 African (ALP) and 244 Non-African (NALP) league players. Eighty-seven „observed events“ occurred, with frequencies of 1.7 and 48.8 injuries per match and per 1000 match hours, respectively. Observed event frequency rose with competition stages, particularly contact mechanism injuries. Non-contact injuries (23/87) predominantly occurred after 60 minutes of play (19/23), with the thigh being the most frequently affected body part (18/87). Older age and playing time significantly correlated with observed event occurrence (p=0.032 and p<0.001, respectively). NALP midfielders and forwards were notably injured by contact mechanisms (36/45) in the attacking zone. Although non-contact mechanisms were more common in ALP than NALP (13/42 vs. 9/45), the difference lacked statistical significance (p=0.240), with a higher rate of muscle injuries (13/42 vs. 10/45, p=0.001). Muscle-related events were the most frequently observed during the 2021 AFCON, with older age and longer playing time identified as key associated factors. These events were more prevalent in ALP compared to NALP.

6 Exploring sports-related concussion awareness and response amongst teenage grassroots soccer players in the UK: a qualitative study

Reference: J Sports Med Phys Fitness. 2026 Jan;66(1):108-119. doi: 10.23736/S0022-4707.25.16671-1.
Authors: Abid Hussain, Dominic Malcolm
Summary: This study examines sports-related concussions (SRC) experiences, beliefs, and behaviors among male and female teenage grassroots soccer players in the UK, focusing on how these are shaped by interpersonal and mediated relations with coaches, parents, and peers. A cross-sectional cohort study informed by interpretivist epistemology and qualitative research design. Data collection involved focus groups, using a topic guide covering SRC knowledge, attitudes, behaviors, and reporting intentions. Focus group sessions were conducted between July 2023 and April 2024. Participants were enrolled through convenience and snowball sampling at a single grassroots soccer club in the UK. Three cohorts of male participants (N.=15) and one cohort of female participants (N.=5) participated in three focus groups each. The 12 focus groups were held at the grassroots soccer academy with the club welfare officer present. Sessions were digitally recorded, transcribed, and analyZed using a framework analysis model. Participants identified and recognized many symptoms associated with SRC, though knowledge was mainly acquired through informal channels (e.g., the media). However, this understanding did not lead to safety-related behavior changes, with significant non-compliance observed among players, parents, and coaches. Effective SRC management requires tailored education programs to overcome barriers and promote safety within grassroots youth soccer. Addressing gender norms and enhancing education can foster a culture of support and accountability, safeguarding the well-being of young athletes. There is a need for better awareness and more precautionary behaviors among all stakeholders in grassroots soccer.

7 Nutritional knowledge and dietary practices in semi-professional and professional Italian soccer players

Reference: J Sports Med Phys Fitness. 2026 Jan;66(1):65-71. doi: 10.23736/S0022-4707.25.17021-7.
Authors: Elena Formisano, Andrea Pasta, Carolina Squeri, Paola C Robotti, Livia Pisciotta
Summary: Soccer is the most practiced sport globally, and adequate dietary intake can significantly impact athletic performance. This study aimed to assess the nutritional knowledge of semi-professional and professional Italian soccer players and evaluate whether their dietary intake aligns with international recommendation for elite soccer players. Male players from two Italian football league teams (one in Category C, one in Category D) participated during the regular season. Demographic and anthropometric data were collected during the initial visit. Nutrition knowledge was evaluated using a simplified version of the „Nutrition for Sport Knowledge Questionnaire“ (NSKQ). Participants completed a 4-day food diary and dietary data were compared against dietary references for elite athletes and soccer players. Twenty-five soccer players (11 from a Category C team and 14 from a Category D team) participated in the study. Total energy intake was consistently below recommendations but increased on match days. Category C players consumed more protein and fat but fewer carbohydrates than Category D players, with significant differences on specific days (P<0.05). The Category D team showed greater adherence to macronutrient intake guidelines: protein (60.7% vs. 38.6%, P=0.023), fat (58.9% vs. 15.9%, P<0.0001), and carbohydrates (23.2% vs. 9.1%, P=0.053). NSKQ scores indicated poor nutritional knowledge in both teams, with no significant correlation between NSKQ scores and dietary adherence. The dietary composition of the Category D team more closely aligned with reference guidelines compared to the Category C team. This discrepancy might reflect differences in dietary habits or nutritional misconceptions.

8 The effect of external focus distance on shooting accuracy in soccer for novice players

Reference: J Sports Med Phys Fitness. 2026 Jan;66(1):40-46. doi: 10.23736/S0022-4707.25.16263-4.
Authors: Aiman Sarhan
Summary: This study evaluated the effects of external focus distance for novice soccer players to determine motor skills and enhancing shooting accuracy in soccer. Soccer demands a unique combination of physicality and technical finesse, with precision, accuracy, and ball-handling skills distinguishing great players. This study aims to investigate the impact of different external focus cues on the shooting accuracy of novice male soccer players during a crossbar challenge. It aims to provide insights for coaches and players to optimize training techniques for skill development. The study involved 45 male participants aged 18-25 who were assigned to the distal external focus, proximal external focus, and control group. Participants performed a practice trial followed by five experimental trials with specific focus instructions. Shooting accuracy was measured using the Loughborough Soccer Shooting Test. Statistical analysis was done using SPSS version 20, which included a mixed paired t-test and one-way ANOVA to compare the group performances. Participants with a distal external focus (M=2.4080) group consistently achieved the highest scores, followed by the proximal external focus group (M=1.5573), with the control group (M=1.3467) having the lowest scores. The study shows that, in comparison to a proximal external focus and a control group, a distal external focus significantly increases soccer shooting accuracy. These findings provide valuable insights for optimizing motor skills and enhancing shooting accuracy in soccer.

9 Travel Distance and Direction Negatively Impact Expected Goal Differential: A Retrospective Analysis of 2018-2023 National Women’s Soccer League Data

Reference: Int J Sports Physiol Perform. 2026 Jan 2:1-6. doi: 10.1123/ijspp.2025-0298. Online ahead of print.
Authors: Owen M Munro, Dean J Norris, Kevin Thomas, Paul Ansdell, Glyn Howatson, Seungbeum D Lee, James P Hocken, Kirsty M Hicks
Summary: This study investigated the impact of travel distance and direction on performance indicators in the US National Women’s Soccer League (NWSL). Data from 510 regular-season matches across the 2019, 2021, 2022, and 2023 seasons were analyzed using open-access data from StatsBombIQ. A multimodal analysis employing linear mixed-effects models was conducted to examine the relationship between travel metrics (distance and direction) and performance outcomes (expected goal differential [xGD]) while controlling for rolling win percentage, opponent rolling win percentage, and game location. Teams performed best at home (xGD = 0.26). Performance declined in all away scenarios: westward travel (xGD = -0.52), neutral time-zone travel (xGD = -0.26), and eastward travel (xGD = -0.01). Pairwise comparisons confirmed a home advantage over all travel conditions: westward (Δ xGD = 0.78), neutral (Δ xGD = 0.51), and eastward (Δ xGD = 0.27). Among away games, westward travel resulted in poorer performance than both eastward (Δ xGD = -0.51) and neutral travel (Δ xGD = -0.26). Eastward travel showed better performance than neutral travel (Δ xGD = 0.25). The most pronounced difference, home versus westward travel (Δ xGD = 0.78), exceeded 0.60 xGD, a magnitude capable of shifting the likely outcome of a match. Travel distance and direction negatively affect performance in NWSL teams, with westward travel posing the greatest detriment. These findings underscore the need for improved scheduling and travel strategies. Future research should explore practical methods to reduce travel-related performance impairments in professional women’s soccer.

10 The Impact of Cold-Water Immersion on Post-Match Recovery in Trained Soccer Players: A Systematic Review and Meta-Analysis

Reference: Scand J Med Sci Sports. 2026 Jan;36(1):e70202. doi: 10.1111/sms.70202.
Authors: Jort Veen, Cecilia Bergh, Yang Cao, Morten Bredsgaard Randers, Peter Krustrup, Peter Edholm
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12767754/pdf/SMS-36-e70202.pdf
Summary: Cold-water immersion (CWI) is widely used by elite soccer players to enhance recovery after match play, yet systematic evidence supporting the effectiveness of this intervention is lacking. This systematic review with meta-analysis aimed to evaluate the effects of CWI on the recovery of physical performance, muscle damage, and delayed muscle soreness in trained soccer players after match play. A systematic database search was conducted and inclusion criteria were: (1) peer-reviewed, controlled trials; (2) competitive soccer players; (3) comparison of CWI with control/placebo after match/simulated match-play; (4) at least one of the following outcomes: 20 m sprint, countermovement jump (CMJ), leg strength via maximal voluntary contraction (MVC), creatine kinase (CK) for muscle damage, or delayed onset of muscle soreness (DOMS); and (5) outcome measurements taken 24, 48 or 72 h post-match. Random-effects meta-analyses were performed to calculate standardized mean differences (SMD) with 95% confidence intervals (CI) and prediction intervals (PI). Ten studies met the inclusion criteria. CWI significantly improved recovery of MVC (SMD = 1.02 [95% CI: 0.55 to 1.50; 95% PI: -0.48 to 2.53]) and CMJ (SMD = 0.38 [95% CI: 0.12 to 0.64; 95% PI: -0.39 to 1.15]), while sprint performance remained unaffected (SMD = -0.59 [95% CI: -1.41 to 0.23; 95% PI: -4.14 to 2.95]). CWI reduced CK levels (SMD = -0.77 [95% CI: -1.17 to -0.37; 95% PI: -2.23 to 0.69]) and alleviated DOMS (SMD = -1.04 [95% CI: -1.91 to -0.17; 95% PI: -4.12 to 2.03]). MVC and CK recovery improved consistently across all time points, while DOMS relief was observed at 24 and 72 h post-match. CMJ benefits were only evident at 48 h post-match. However, as the 95% PIs for all outcomes included the null effect, the observed benefits should be interpreted cautiously, as future studies may yield smaller or null effects. Overall, CWI may enhance recovery of muscle strength, reduce muscle damage, and alleviate soreness in trained male and female soccer players, but does not seem to impact sprint performance, and its effect on CMJ is time-dependent.

11 Effects of a 90-Min Nap on Time-Motion Metrics and Psychophysiological Responses During Small-Sided Games in Professional Soccer Players

Reference: Scand J Med Sci Sports. 2026 Jan;36(1):e70193. doi: 10.1111/sms.70193.
Authors: Mohamed Kerkeni, Omar Boukhris, Manel Kerkeni, Achraf Ammar, Waqar Husain, Piotr Zmijewski, Haitham Jahrami, Hamdi Chtourou, Khaled Trabelsi
Summary: This study investigated the impact of a 90-min nap (N90) on time-motion metrics and psychophysiological responses during small-sided games (SSGs) in soccer players. In a within-subjects counterbalanced design, 15 professional male soccer players (mean ± SD; age: 22.4 ± 1.2 years; stature: 178 ± 9 cm; body mass: 70.1 ± 4.0 kg; estimated VO2max: 55.9 ± 2.8 mL·min-1·kg-1) completed two SSGs sessions under N90 and no-nap (N0) conditions. N90 was monitored using a Fitbit Charge 6 wristband. Daytime sleepiness was assessed pre- and post-nap. Mood states, the wellness status (Hooper index), and cognitive performance (Go/NoGo task) were evaluated before each SSGs session. Time-motion metrics, obtained via the FieldWiz GPS system, along with exercise heart rate (HR), were continuously monitored throughout the SSGs. Blood lactate concentration ([La]) and ratings of perceived exertion (RPE) were assessed post-SSGs. Compared to N0, the N90 condition resulted in a significantly greater total distance covered during SSGs (p = 0.002, Cohen’s |d| = 0.96), lower presession resting HR (p < 0.001, |d| = 1.33), and reduced relative exercise HR (p = 0.03, |d| = 0.33). Additionally, post-SSGs [La] and RPE were lower following N90 (p = 0.015, |d| = 0.71 and p = 0.001, |d| = 1.03 respectively). The N90 also led to higher vigor scores (p = 0.003, |d| = 1.01), lower Hooper index values (p = 0.02, |d| = 0.59), and faster reaction time (p = 0.02, |r| = 0.60) than N0. A 90-min nap before SSGs training increased total distance covered, reduced perceived fatigue, and enhanced mood, wellness, and cognitive alertness. These findings support implementing a 90-min nap as a practical ergogenic aid to optimize recovery status, performance, cognitive alertness and overall well-being in professional soccer players.

12 Effects of Kinetic- and Kinematic-Oriented Change-of-Direction Training on Anterior Cruciate Ligament Risk Factors in Elite Soccer Players Under Fatigue

Reference: J Strength Cond Res. 2026 Jan 5. doi: 10.1519/JSC.0000000000005320. Online ahead of print.
Authors: Tolga Altug, Mehmet Soyler, Ahmet Serhat Aydin, Seyfullah Celik, Christopher B Taber
Summary: This study investigated the effects of repeated change-of-direction (COD) drills on body composition and performance outcomes in elite U17 soccer players, examining fatigue-induced changes in anterior cruciate ligament (ACL) injury risk mechanisms. Twenty-eight male athletes (age: 16.8 ± 0.6 years; height: 167.4 ± 2.3 cm; body mass: 63.50 ± 2.19 kg; fat mass (FM): 5.31 ± 0.90 kg; fat-free mass (FFM): 58.20 ± 0.84 kg) were randomly assigned to either a kinetic group emphasizing resistance-based force production or a kinematic group targeting agility and COD mechanics. A 12-week in-season intervention was conducted, with pretest and posttest evaluations of heart rate (HR), blood lactate (LA), rating of perceived exertion (RPE), FM, FFM, COD time, and shuttle sprint (SS) performance. Significant group × time interactions were observed for FM (F (1, 26) = 6.07, p = 0.021, η2 = 0.189), SS (F (1, 26) = 5.75, p = 0.024, η2 = 0.181), and RPE (F (1, 26) = 13.52, p = 0.001, η2 = 0.342), favoring the kinetic group. These athletes exhibited greater reductions in FM, smaller increases in sprint time, and elevated RPE, indicating improved fatigue tolerance. No interaction effects were found for COD, HR, or LA, but the kinetic group exhibited more effective within-group adaptation to training-induced fatigue. Overall, kinetic-based COD training may support neuromuscular and metabolic adaptation under fatigue, while kinematic approaches may better preserve movement quality. A combined approach may mitigate fatigue-related ACL injury risk during competition.

13 Evaluation of DAid® Smart Socks for Foot Plantar Center of Pressure Measurements in Football-Specific Tasks: A Preliminary Validation Study

Reference: Healthcare (Basel). 2025 Dec 27;14(1):76. doi: 10.3390/healthcare14010076.
Authors: Anna Davidovica, Guna Semjonova, Aleksejs Kataševs, Aleksandrs Okss, Darja Nesterovica, Signe Tomsone
Download link: https://www.mdpi.com/2227-9032/14/1/76
Summary: Accurate plantar pressure assessment is essential for injury prevention and rehabilitation monitoring in sports. Wearable sensor technologies, such as DAid® Smart Socks, offer portable, real-time biomechanical feedback and enable data collection in field conditions. However, there is limited evidence on their level of agreement with a gold standard in measuring the foot plantar center of pressure (CoP) in football-specific tasks. This study aimed to determine the preliminary validity of DAid® Smart Socks compared with a gold-standard force platform in measuring plantar center of pressure (CoP) during functional football FIFA 11+ Part 2 exercises.  Ten male volunteer youth football players (mean age 12.2 ± 0.42 years; height 158.7 ± 7.72 cm; weight 46.46 ± 8.78 kg; shoe size EU 39.8 ± 2.68) from the Latvian Football Federation Youth League participated. Eight players had right-leg dominance, two had left-leg dominance; three reported past lower-limb injuries. Plantar pressure was measured simultaneously using DAid® Smart Socks and a 1.5 m entry-level force platform with a calibration factor of 3.2. Center of pressure (CoP) data from the force platform were recorded using Footscan software version 9.10.4. Participants performed two selected FIFA 11+ Part 2 exercises-a single-leg squat (unilateral) and a squat with heel raise, performed bilaterally-under standardized conditions. Each exercise was performed twice, with sock removal and reapplication between trials. Agreement between the DAid® Smart Socks and the force platform was examined using waveform synchronization, root mean square error (RMSE), Bland-Altman analysis, and Lin’s Concordance Correlation Coefficient (CCC) to quantify both relative waveform correspondence and absolute CoP measurement accuracy.  Across 160 paired recordings, the DAid® Smart Socks showed moderate-to-high correlation with the force platform for relative CoP dynamics, with 79% of waveforms demonstrating CCC ≥ 0.60. Absolute agreement was limited, with only 16% of recordings reaching CCC ≥ 0.90, and RMSE values ranging from 2.1 to 18.9 mm (X) and 4.3-34.2 mm (Y).  DAid® Smart Socks showed moderate-to-high correspondence with the force platform in capturing the directional and temporal characteristics of plantar CoP during functional football tasks, with agreement varying across individuals.

14 The Power of Belief: Investigating the Placebo Effect in Post-Exercise Recovery Strategies for Football Players

Reference: Healthcare (Basel). 2025 Dec 19;14(1):4. doi: 10.3390/healthcare14010004.
Authors: Marco Pernigoni, Andrius Osvaldo Alfieri, Audinga Kniubaitė, Sigitas Kamandulis, Daniele Conte, Inga Lukonaitienė
Summary: The objective is assessing whether the placebo effect can influence the time course of recovery following a football match. Using a randomized crossover design, eighteen youth male players (age: 15.3 ± 0.5 years, stature: 178.7 ± 6.4 cm, body mass: 65.3 ± 7.6 kg, playing experience: 8.6 ± 1.5 years) completed two friendly matches, followed by placebo (PLA; sham vagus nerve stimulation) or passive rest (CON). To assess the impact of PLA, countermovement jump height (CMJ), 10 and 20 m sprint times, heart rate variability (Ln-rMSSD), static and dynamic muscle soreness, and perceived fatigue were measured at pre-match, post-match, post-recovery, and 24 h post-match.  Our findings indicate that match play induced substantial fatigue, with significant deteriorations [p ≤ 0.002, small-to-large effect sizes (ES)] in CMJ, 10 and 20 m sprint performance, Ln-rMSSD, muscle soreness, and perceived fatigue at post-match and post-recovery compared to pre-match (except Ln-rMSSD between pre-match and post-recovery: p = 0.151, small ES). Although no significant between-intervention differences were found for any variable at any time point (p > 0.05), effect size analysis showed moderately lower perceived fatigue (r = 0.40) and dynamic soreness (r = 0.32) in PLA compared to CON at post-recovery.  These findings suggest that while placebo stimulation did not affect performance or heart rate variability, it may support perceptual recovery. This holds relevance for both research and practice, as including placebo conditions can help isolate psychological effects from true treatment responses, while promoting positive expectations may enhance the perceived effectiveness of recovery strategies.

15 Maturity-Related Responses to Small-Sided Games in Youth Football

Reference: Sensors (Basel). 2025 Dec 24;26(1):134. doi: 10.3390/s26010134.
Authors: Gonzalo Fernández-Jávega, Ismael Castellano-Galvañ, Manuel Moya-Ramón, Iván Peña-González
Summary: Biological maturation strongly influences youth players‘ physical performance, yet its role in shaping training load responses remains unclear. This study examined how maturation status affects physical adaptations and the relationship between internal load (IL) and external load (EL) during an 8-week small-sided game (SSG) training program in youth football. Fifty-three players were allocated to an experimental group (EG) or control group (CG). EL during SSGs was continuously monitored using 10 Hz GPS units with inertial sensors, while session-RPE quantified IL. Intermittent endurance (vIFT) and 5 m and 30 m sprint performance were assessed before and after the intervention. Players were categorized by years from peak height velocity (PHV). No between-group differences were found in EL variables; however, IL was significantly lower in more mature players. The EG showed a significant improvement in vIFT, whereas sprint performance remained unchanged and the CG showed no improvements. Both maturity groups increased vIFT similarly, with no interaction between maturation status and training adaptation. These findings indicate that SSG-based training effectively enhances intermittent endurance regardless of biological maturity, although less mature players experience higher perceived exertion under equal mechanical demands. Maturation status should therefore be considered when prescribing and interpreting training loads in youth athletes.

16 Effects of High-Dose Vitamin D Supplementation and Physical Exercise on Vitamin D Metabolites in Professional Football Players: A Pilot Study

Reference: Nutrients. 2026 Jan 5;18(1):175. doi: 10.3390/nu18010175.
Authors: Anna Książek, Aleksandra Zagrodna, Konrad Kowalski
Download link: https://www.mdpi.com/2072-6643/18/1/175
Summary: Vitamin D plays an important role in muscle metabolism and recovery, yet its kinetics during and after football-specific physical activity remain poorly understood. Therefore, this study aimed to determine whether physical effort during a football match influences the concentration of vitamin D metabolites and to explore the effect of a single high-dose cholecalciferol supplementation combined with physical exercise on the levels of vitamin D metabolites in professional football players.  Twenty professional football players participated in a three-phase, randomized placebo-controlled pilot study. Baseline fitness and blood samples were collected, followed by pre- and post-match measurements during two games. In the final phase, half of the players received a single 500,000 IU dose of vitamin D3 before a simulated match. Blood samples were collected before and after each session to analyze vitamin D metabolites using the isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method.  Physical exercise during the football match significantly increased serum concentrations of 25-(OH)D3, 24,25-(OH)2D3, and 3-epi-25-(OH)D3 (by up to 25%, p < 0.001). Following supplementation, these effects were further amplified, with 25-(OH)D3 rising by 98% and 3-epi-25-(OH)D3 by 424% (p < 0.001). Significant alterations in vitamin D metabolite ratios after exercise and supplementation suggest enhanced metabolic turnover and dynamic regulation of vitamin D pathways in response to physical effort.  Football-specific physical activity appears to stimulate the release of vitamin D metabolites. High-dose cholecalciferol supplementation was well tolerated and may rapidly increase vitamin D status in professional athletes. These findings may have implications for optimizing recovery and performance, though larger trials are needed.

17 Development and validation of a machine learning model for non-contact injury prediction based on lower limb strength asymmetry in professional football

Reference: Sci Rep. 2026 Jan 9. doi: 10.1038/s41598-025-34468-4. Online ahead of print.
Authors: Yongzhen Wang, Seongno Lee
Download link: https://www.nature.com/articles/s41598-025-34468-4_reference.pdf

18 Short-term – change on physical capacities of football players within few days before ACL-injury: a retrospective case-control study

Reference: BMC Sports Sci Med Rehabil. 2026 Jan 9. doi: 10.1186/s13102-025-01518-3. Online ahead of print.
Authors: Andreas Kopf, Maximilian Getzreiter, Andreas Wittke, Emre Nokay, Markus Gesslein, Volker Alt, Werner Krutsch, Dominik Szymski
Download link: https://link.springer.com/content/pdf/10.1186/s13102-025-01518-3_reference.pdf
Summary: Anterior cruciate ligament (ACL) ruptures represent one of the most severe injuries in professional football, often resulting in long rehabilitation, impaired performance, and increased risk of re-injury. The aim of this study was to investigate whether performance parameters derived from match statistics can serve as early indicators of ACL rupture in professional male football players. A retrospective case-control design was applied. Forty-two male professional football players from the German Bundesliga and 2. Bundesliga with confirmed ACL ruptures between 2016 and 2024 were included, alongside 42 matched controls from the same teams and positions. Match performance data from ten games preceding the injury were analyzed. Parameters included minutes played, total distance covered, number of sprints, maximal speed, pass accuracy, number of duels, and duel success rate. Independent t-tests compared injured and control players across individual matchdays and aggregated intervals (the average values across the last four, three, and two matches before injury). Additionally, odds ratios (OR) with 95% confidence intervals were computed based on upper (≥ 75th percentile) and lower (≤ 25th percentile) quartile thresholds to quantify the relative risk associated with extreme performance values. Injured players showed higher maximum speed that consistently differentiated them from controls, with significant differences at matchday 2 (p = 0.005, OR = 3.42, 95% CI 1.45-8.06) and across all aggregated intervals (p = 0.015-0.031). Injured players also showed significantly fewer minutes played at matchday 2 before injury (p = 0.046, OR = 2.36, 95% CI 1.01-5.51) and across certain intervals (last four and three matches before injury; p = 0.027-0.044). Analysis of matchdays 5-10 revealed no significant group differences for any performance parameter, confirming that relevant performance changes manifest primarily in the immediate pre-injury period. No significant group differences emerged for distance covered, sprint count, pass accuracy, or duel frequency between ACL injured players and controls. Maximum speed showed the strongest association with ACL rupture risk, with significant differences at matchday 2 (p = 0.005) and across aggregated intervals (the average values across the last four, three, and two matches before injury). Reduced playing time emerged as an additional indicator. Although distance covered, sprint count, and pass accuracy did not reach statistical significance individually, their temporal patterns revealed a predisposing risk constellation: injured players demonstrated reduced cumulative exposure combined with acute high-intensity spikes at matchday 2, declining technical precision, and increased physical confrontation at matchday 1. This suggests ACL injury risk manifests through deterioration of integrated performance capacity under acute load fluctuations rather than isolated thresholds. Multifactorial approaches integrating biomechanical, physiological, and temporal performance patterns are essential for effective ACL injury prevention in professional football.

19 Effects of a 15-week recreational football programme on insulin resistance and glycaemic control in inactive premenopausal women with mild arterial hypertension: A randomised controlled trial

Reference: J Sports Sci. 2026 Jan 8:1-11. doi: 10.1080/02640414.2025.2609442. Online ahead of print.
Authors: Susana Póvoas, Carlo Castagna, Luke J Connolly, Peter Krustrup, Tórur Sjúrðarson, May-Britt Skoradal, Magni Mohr
Summary: This study aimed to investigate the impact of a 15-week recreational football intervention on insulin resistance and glycaemic control in inactive premenopausal women with mild hypertension. A total of 41 women, aged 35-50 years, were randomised into either a football training group or a control group. The football group participated in structured, small-sided games-based training sessions, three times per week, while the control group remained inactive. Key outcomes measured included insulin resistance, fasting glucose and insulin concentrations, as well as glucose and insulin responses after an Oral Glucose Tolerance Test (OGTT). Despite the intervention, no significant differences were found between the football and control groups in fasting glucose, insulin levels, or insulin resistance measured by HOMA-IR. Additionally, the OGTT results showed no significant changes in glucose or insulin responses across the intervention period. This study also assessed plasma levels of sICAM-1 and sVCAM-1, key markers of vascular function, which showed no significant changes related to the intervention. These findings suggest that 15 weeks of recreational football may not be sufficient to produce significant improvements in glycaemic control in inactive premenopausal women with mild hypertension, although larger confirmatory studies are required to test this hypothesis.

20 Coaching strategies and performance patterns in elite Italian football: a comparative analysis of possession and direct-play styles

Reference: J Sports Med Phys Fitness. 2026 Jan;66(1):47-56. doi: 10.23736/S0022-4707.25.17359-3.
Authors: Bruno Ruscello, Francesco Cantore, Gabriele Morganti, Elvira Padua, Cristoforo Filetti, Marco Porta, Gianluca Briotti, Laura Pantanella
Summary: This study examines how coaching strategies influence performance patterns in elite Italian football, comparing the possession-based „building-from-the-back“ style with a direct approach. Observational data from all 380 matches of the 2022-2023 Serie A season, sourced from a public online platform, were categorized by playing style based on goalkeeper distribution patterns. Teams favoring the „building-from-the-back“ strategy (Group 1) achieved superior results compared to those adopting direct play (Group 2). On average, Group 1 earned more points (63.8±14.4 vs. 40.2±14.1, P<0.002), scored more goals (57.3±10.5 vs. 40.1±12.5, P=0.004), and conceded fewer (42.4±10.4 vs. 55.0±10.9, P=0.017). They also recorded a higher goal difference (+14.9 vs. -14.9, P=0.003), greater ball possession (53.1±4.3% vs. 46.9±5.0%, P=0.009), more shot-creating actions (906.6±128.4 vs. 777.9±133.2, P=0.041), and more goal-scoring actions (97.7±17.3 vs. 64.8±24.0, P=0.003). Logistic regression showed that teams using build-up play were 13.5 times more likely to qualify for European competitions (95% CI: 1.20-152.0), with six of the seven qualified teams adopting this style. Effect sizes across metrics were consistently large (Cohen’s d: 0.94-1.65). Possession-oriented teams outperformed direct-play teams in both offensive and defensive indicators, underscoring the strategic role of coaches in orchestrating effective build-up play. These descriptive findings highlight how tactical choices are strongly associated with measurable outcomes in elite Italian football, offering data-driven insights for coaching methodologies and future research.

21 One in three reports pain in a given week: a one-season prospective study on prevalence of pain and analgesic use in amateur female and male football players

Reference: BMJ Open Sport Exerc Med. 2026 Jan 3;12(1):e002851. doi: 10.1136/bmjsem-2025-002851. eCollection 2026.
Authors: Sofi Sonesson, Ida Åkerlund, Kalle Torvaldsson, Emmanuel Bäckryd, Hanna Lindblom, Martin Hägglund
Download links: https://pmc.ncbi.nlm.nih.gov/articles/PMC12766771/pdf/bmjsem-12-1.pdf
Summary: The aim was to study the prevalence of pain and analgesic use in amateur football players and explore sex-based and age-based differences. A prospective cohort study of 316 amateur football players (185 females, 131 males), mean age 20 years (range 15-54). Baseline data on demographics and pain history in the preceding season were collected. Players reported training/match participation, pain, analgesic use and injuries every 2 weeks over a 7-month season (April-October 2023). 2439 weekly reports were analysed. Weekly pain prevalence was 40.7% (95% CI 36.4% to 45.4%) in female players and 37.2% (32.4% to 42.7%) in male players. Moderate to severe pain was more frequently reported in youth females than youth males (weekly prevalence 20.5% (15.8% to 26.8%) vs 13.1% (9.6% to 17.9%), p=0.032). Female players reported more analgesic use than male players (27.6% (23.8% to 32.1%) vs 11.2% (8.4% to 14.8%), p<0.001). Gradual-onset injuries were the predominant cause of pain (47% in females, 50% in males). Over-the-counter paracetamol (female 70%, male 61%) and non-steroidal anti-inflammatory drugs (female 67%, male 44%) were most commonly used. Analgesic use was primarily driven by non-injury-related pain in females and gradual-onset injuries in males. Pain was common among amateur football players, with more than one-third of players reporting pain in a given week. Female youth players reported higher prevalence of moderate to severe pain, and both female youths and female adults used more analgesics than male counterparts. These findings call for sex-specific pain strategies and educational programmes targeting pain and medication management in amateur sports.

22 Electrocardiographic diversity in football players: how distinct ethnic patterns shape athletes‘ hearts

Reference: Eur J Prev Cardiol. 2026 Jan 6;33(1):6-7. doi: 10.1093/eurjpc/zwaf536.
Authors: Filipe Ferrari, Ricardo Stein, Mauricio Milani
Download link: https://watermark02.silverchair.com/zwaf536.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAA1MwggNPBgkqhkiG9w0BBwagggNAMIIDPAIBADCCAzUGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMMAiHsqW2akRP5Z_kAgEQgIIDBoXgi4dsT2xJiaI56l9tdHOQ3qg84KtB0FIDI_OAxz4rwVB5TlSmA3LCbZBu0DQqCE-J1ItCEcpawx-6nwsHAXR5cdWn2OcQIZC6-ABFX1f_KUt0ZqEKfJKIcOTx06f0U9HhdoGZWvdC5DiG8obrgIY6DTiC6G7AW6EQGFCJBzECtsVKPaAp_iDfM1I1pJR_CUF_t6Z46K9t25onBL7k1HaDWFf2i81Q5UUAMAfbmVEAQo0hQGey5hFoXxvwGXTdAdgci8ny5Y2AmduqLBrgoGf_caEFQxYyn1xMX35c17L278JamD3GjzFRXe6JJrMMMb8jKSj-BvGnbS8K0r01Lt8A6p-GSnm0hoYc4wdHRZHTU_7Q9iKwB7vYxJBVZUYhk3t2mAMBkk8jBG-E1rMLrDVapQNFmxX-wM-B-hTdKUZOfTtGl3Y3hVT1yk2T0X66TTmsMUAmTYGMfARgQPOnFOPSbVScyPM6GosVZ3zmDTbjbZEcdAnBDq50J1e0fQbY8pNxwhXuS1hVjLoYcPClm-NZybEgkrRcOjCRBj2-beh9n0-MksS1Wm9tz0PyaSNj46792b64UEJHMoM5oE132eYqIyrroWx2rjlcEKjU66uPQcs5LkxmRe6Ejl5rK18B4RGSOEEqAQAj98IOkOEJKsdp-_TbPLAJd5a6X-TS89NOo1lDpOM7cki3XYs3uAR8Ark9aaVIkRvl4x0uA01OgmuQNbyQxVTpfV6-FvxM2Y0hia2BBRemba_lZ33hLY4ajQ5Ta8Ncu8hiGmy9Fq33C-LkliZjhSLLEOdzOq_kRydIijaNr9NHzuxo6xDrwdRlHQEZO9W1uSZNfFMP_XffLCfSpJWqlCynD3kgsfU76fj6dC9s5g6h1l5JskKuHPJCF0167sCLnNVgMnhvSVMVFk7Eh2erfQ-31y-bRB3IpaxQrdtnsZj4rPvyHOGLoiVoX655m0yHIA0-5MYGF-NOSYhZnjImsN7gnWAi8xp4fqHr6A0xq_8YLGpvmkdPy0iec495Kcao2A