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 Relationship between the cervical spine and impacts whilst heading the ball in adolescent male soccer players

Reference: J Sports Sci. 2025 Feb 21:1-11. doi: 10.1080/02640414.2025.2465945. Online ahead of print.
Authors: Felix T Leung, Hugo G Espinosa, David Rowlands, Matthew T O Worsey, Brittany Grantham, M Dilani Mendis, David V Thiel, Julie A Hides
Summary: There has been considerable public concern regarding the effects of repetitive head impacts associated with heading the ball in soccer. This is relevant for adolescents whose brains are undergoing rapid development. The study investigated the relationship between strength, proprioception, endurance and range of motion of the cervical spine and impacts associated with heading the ball in adolescent male soccer players. The participants were 20 skilled players aged 15-18 years. Outcome measures included questionnaires, assessments of cervical spine function (range of motion, joint position error, isometric muscle strength and endurance) and the ratio of maximum head acceleration to maximum T3 acceleration (impact ratio) during each ball impact when heading the ball. Results showed that increased range of motion of extension of the cervical spine and lower joint position error in flexion of the cervical spine were associated with higher impact ratios. Greater isometric strength of the lateral flexors was associated with lower impact ratios. Endurance of the deep neck flexors was not associated with impact ratios. Strength training may be beneficial to decrease head impacts during soccer ball heading, especially in those with increased range of motion of extension of the cervical spine.

2 Sensitivity to change of quadriceps and hamstrings muscle wearable electromyography outcomes during a professional soccer match

Reference: J Sports Sci. 2025 Feb 21:1-10. doi: 10.1080/02640414.2025.2469462. Online ahead of print.
Authors: Rudy N Kalema, Steven J Duhig, Taija Finni, Ashokan Arumugam, Arto J Pesola
Summary: Textile electromyography (EMG) was used to investigate neuromuscular activity during professional soccer matches, providing insights into performance optimization and injury prevention. This explorative study aimed to (1) describe the EMG activity of the quadriceps and hamstrings and (2) identify the metrics most sensitive to changes between the first and second half. Seven players (age: 23.1 ± 5.7 years; height: 1.82 ± 0.05 m; weight: 77.6 ± 10 kg) were evaluated. EMG outcomes included EMG amplitude, intensity distribution, and usual bout duration for dominant (D) and non-dominant (N.D) muscles. Hamstring activity averaged 47% (D) and 43% (N.D) of %EMGMVC, while quadriceps averaged 32% (D) and 27% (N.D). Most time was spent at the lowest EMG intensity and 13% at the highest intensity. Bout amplitudes (37-54%EMGMVC) and durations (14-17s) varied between muscle groups and limbs. The hamstrings‘ usual EMG bout amplitude (N.D) was the most sensitive, showing a 12% reduction (effect size [ES] = 0.64, p = 0,01). The most substantial percentage change was observed in the hamstrings‘ duration > 100% EMGMVC (D), which decreased by 27% (ES = 0.14, p = 0.57) with other metrics showing smaller reductions. This study highlights the potential of textile EMG to quantify neuromuscular demands during soccer matches, offering valuable tools for performance monitoring and tailored interventions to enhance training and prevent injuries.

3 Morning sprint interval training produces greater physical performance adaptations than evening training in soccer players

Reference: Sci Rep. 2025 Feb 20;15(1):6154. doi: 10.1038/s41598-025-89821-4.
Authors: Bizheng Yan, Lei Li
Summary: While the literature provides evidence supporting the effectiveness of evening sprint interval training (SIT), there remains a limited amount of research investigating the effects of morning SIT among soccer athletes. This study examined the effects of morning versus evening SIT during the preparatory phase on physical and physiological performance in collegiate soccer players. Thirty male players volunteered to participate in the study and were randomly divided into morning, evening, or control groups, each group consisting of 10 subjects. The evaluation of physical (countermovement vertical jump [CMVJ], 20-m sprint, Illinois change of direction, and Yo-Yo intermittent recovery test level 1 [Yo-Yo IR1]) and physiological (graded exercise test and Wingate anaerobic power test) performance took place prior to and following the 7-week SIT, both in the morning and evening testing sessions. Both training groups showed significant improvements in physical and physiological performance from pre- to post-training, regardless of testing session timing (p < 0.05). The morning SIT group exhibited greater adaptive changes (p < 0.05) compared to the evening SIT group in CMVJ, 20-m sprint, Yo-Yo IR1, peak and mean power outputs at both the morning and evening testing sessions. These findings suggest that male soccer players can benefit from both morning and evening SIT sessions; however, conducting SIT in the morning could result in greater adaptive changes than evening training. To optimize physical performance adaptations, coaches should schedule SIT sessions in the morning. It is recommended to schedule conditioning workouts in the morning and team practices in the afternoon for optimal adaptations.

4 Strategic Insights Into One-Touch Finishing in Soccer: Analyzing Play During Copa America 2021

Reference: Percept Mot Skills. 2025 Feb 20:315125251320129. doi: 10.1177/00315125251320129. Online ahead of print.
Authors: Michalis Mitrotasios, Spyros Plakias, Vasilis Armatas, Alliance Kubayi, Paul Larkin
Summary: Goal scoring is critical in soccer, but limited research exists on one touch finishing in open play situations. This study addresses this gap by analyzing one touch finishing in the Copa America 2021. The aim was to evaluate the effectiveness of one touch finishing and identify the conditions under which they are most successful in competitive soccer matches. This was an observational study using video analysis of Copa America 2021 matches. 544 goal scoring attempts from 28 matches in the Copa America 2021 tournament. Video footage was coded using Hudl Sportscode software to capture relevant game indicators related to final attempts. Chi-square tests examined associations between touches and various match factors. Binary logistic regression analyzed the impact of touches on goal scoring success. One touch finishing significantly enhanced goal scoring chances compared to multiple touch attempts, especially when executed from within the penalty area and as part of elaborate attacks. Assists from crosses and cutbacks facilitated successful one touch finishing. Binary logistic regression confirmed one touch finishing was three times more likely to result in goals. One touch finishing is highly effective for goal scoring in competitive soccer. Coaches should emphasize quick, decisive actions in high-pressure zones and develop targeted training programs to enhance one touch finishing efficiency.

5 The principles of tactical formation identification in association football (soccer) – a survey

Reference: Front Sports Act Living. 2025 Feb 5:6:1512386. doi: 10.3389/fspor.2024.1512386. eCollection 2024.
Authors: Hadi Sotudeh
Download link: https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2024.1512386/full
Summary: This paper reviews the principles employed to identify team tactical formations in association football, covering over two decades of research based on event and tracking data. It first defines formations and discusses their history and importance. It then introduces the preprocessing and team/position-level principles. Preprocessing includes match segments and normalized locations followed by data representation using various options, such as average locations, hand-engineered features, and graphs for the team-level and relative locations, distributions, and images for the position-level approaches. Either of them is later followed by applying templates or clustering. Among the limitations for future research to address is the reliance on spatial rather than temporal aggregation, which bases formation identification on newly introduced coordinates that may not be available in raw tracking data. Assuming a fixed number of outfield players (e.g., 10) fails to address scenarios with fewer players due to red cards or injuries. Additionally, accounting for phases of play is crucial to provide more practical context and reduce noise by excluding irrelevant segments, such as set pieces. The existing formation templates do not support arrangments with more or fewer players in each horizontal line (e.g., 6-3-1). On the other hand, clustering forces new observations to be described with previously learned clusters, preventing the possibility of discovering emerging formations. Lastly, alternative evaluation methods should have been explored more rigorously, in the absence of ground truth labels. Overall, this study identifies assumptions, consequences, and drawbacks associated with formation identification principles to structure the body of knowledge and establish a foundation for the future.

6 Injury risk profile for soccer players: identification of the risk factors for soccer-related injuries – an umbrella review

Reference: Res Sports Med. 2025 Feb 22:1-27. doi: 10.1080/15438627.2025.2467867. Online ahead of print.
Authors: Federico Genovesi, Marco Tabone, Stefano Nuara, Elena Pasquali, Alessio Rossi, Andrea Perali, Tindaro Bongiovanni
Summary: This review aimed to identify risk factors for soccer injuries and provide researchers the needed elements to build a soccer-player’s injury risk profile. An umbrella review was conducted following the PRIOR criteria (OSF registration link: https://osf.io/jr7xe/). A literature search was run to identify studies investigating soccer-related injury risk factors. We included systematic reviews published between 2013 and 2023 related to soccer and analysed the identified risk factors to classify these in intrinsic and extrinsic, group in categories and identify relationships between risk factors and injury location. Among 240 risk factors, 181 (75.4%) were classified as intrinsic and 59 (24.6%) as extrinsic. We grouped risk factors in 14 categories. Finally, we found relationships between risk factors and injury locations for 159 factors, with the knee representing the body area most affected by risk factors (N = 101), followed by the ankle (N = 65) and the thigh (N = 65).

7 Effects of different dietary supplements on athletic performance in soccer players: a systematic review and network meta-analysis

Reference: J Int Soc Sports Nutr. 2025 Dec;22(1):2467890. doi: 10.1080/15502783.2025.2467890. Epub 2025 Feb 19.
Authors: Hua Luo, Tengku Fadilah Tengku Kamalden, Xiaolin Zhu, Changqing Xiang, Nurul Amelina Nasharuddin
Summary: As dietary supplements play a crucial role in meeting the unique nutritional needs of soccer players, a growing body of studies are exploring the effects of dietary supplements on athletic performance in soccer players. The effectiveness of certain supplements, such as caffeine and creatine, remains debated due to inconsistent results across studies. Therefore, this systematic review and Bayesian network meta-analysis was conducted to tentatively identify the most effective dietary supplements for soccer players. We searched PubMed, Web of Science, Cochrane, Embase, and SPORTDiscus from database establishment to 5 February 2024 to identify randomized controlled trials (RCTs) evaluating the effects of different dietary supplements on athletic performance in soccer players. The risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomized trials. A Bayesian network meta-analysis was performed using the R software and Stata 18.0. A subgroup analysis was conducted based on the competitive level of the athletes. Eighty RCTs were included, with 1,425 soccer players randomly receiving 31 different dietary supplements or placebo. The network meta-analysis showed that compared with placebo, carbohydrate + protein (SMD: 2.2, very large), carbohydrate + electrolyte (SMD: 1.3, large), bovine colostrum (SMD: moderate) and caffeine (SMD: 0.29, small) were associated with a significant effect on increasing the distance covered. Kaempferia parviflora (SMD: 0.46, small) was associated with a significant effect on enhancing muscular strength. Beta-alanine (SMD: 0.83, moderate), melatonin (SMD: 0.75, moderate), caffeine (SMD: 0.37, small), and creatine (SMD: 0.33, small) were associated with a significant effect on enhancing jump height. Magnesium creatine chelate (SMD: -3.0, very large), melatonin (SMD: -1.9, large), creatine + sodium bicarbonate (SMD: -1.4, large), and arginine (SMD: -1.2, moderate) were associated with a significant effect on decreasing sprint time. Creatine + sodium bicarbonate (SMD: -2.3, very large) and caffeine (SMD: -0.38, small) were associated with a significant effect on improving agility. Sodium pyruvate (SMD: 0.50, small) was associated with a significant effect on increasing peak power. Magnesium creatine chelate (SMD: 1.3, large) and sodium pyruvate (SMD: 0.56, small) were associated with a significant effect on increasing mean power. Carbohydrate + electrolyte (SMD: -0.56, small) was associated with a significant effect on improving the rating of perceived exertion. This study suggests that a range of dietary supplements, including caffeine, creatine, creatine + sodium bicarbonate, magnesium creatine chelate, carbohydrate + electrolyte, carbohydrate + protein, arginine, beta-alanine, bovine colostrum, Kaempferia parviflora, melatonin, and sodium pyruvate, can improve athletic performance in soccer players. This review provides evidence-based guidance for soccer coaches and nutritionists on using dietary supplements to enhance specific performance measures.

8 Exploring How Soccer Players With Perfectionism Navigate Challenges in Talent Pathways

Reference: J Sport Exerc Psychol. 2025 Feb 18:1-12. doi: 10.1123/jsep.2024-0166. Online ahead of print.
Authors: Tracy C Donachie, Sarah H Mallinson-Howard, Andrew P Hill, Katherine A Tamminen
Summary: The study provides a qualitative exploration of how soccer players reporting perfectionism navigate challenges in talent pathways. Eighteen players (10 females, eight males, Mage = 16.17 years, SD = 3.47) from talent pathways with higher levels of perfectionism and perfectionistic cognitions (1SD above the mean of samples from previous studies) participated in semistructured one-to-one interviews. Using semantic thematic analysis, seven themes were identified: cycles of anxiety, sadness at being a substitute, self-criticism and hopelessness during slumps, ruminating on mistakes, worthless when injured, shame in success and intolerance of defeat, and psychological distress. Participants experienced heightened anxiety, especially when substituted, and responded to poor performance, mistakes, and injuries with self-criticism and unhelpful emotions. Postmatch, they ruminated over both success and defeat, with some reporting extreme psychological difficulties. The findings highlight how aspiring soccer players perceived perfectionism as a barrier to overcoming challenges, hindering both their performance and well-being.

9 Optimizing the number of players and training bout durations in soccer small-sided games: Effects on mood balance and technical performance

Reference: Eur J Sport Sci. 2025 Mar;25(3):e12208. doi: 10.1002/ejsc.12208.
Authors: Zouhaier Farhani, Hatem Ghouili, Wissem Dhahbi, Achraf Ammar, Mohamed Ben Aissa, Mohamed Mansour Bouzouraa, Khaled Trabelsi, Noomen Guelmami et al.
Summary: This study aimed to determine the effects of different bout durations (1 × 12 min, 2 × 6 min and 3 × 4 min) of three-a-side (3vs3) and four-a-side (4vs4) small sided games (SSGs) with goalkeepers, on the profile of mood state (POMS) scores, and technical performance (percentage of successful passes, percentage of successful tackles, percentage of successful duels, and percentage of ball loss) in soccer players. Sixteen semiprofessional male soccer players participated in the study (age: 20.7 ± 0.7 years, height: 179.5 ± 6.1 cm, body mass: 67.2 ± 4.9 kg, body fat: 10.7 ± 0.7%). In randomized counterbalanced order, participants completed the six different conditioned SSGs (2 playing-formats × 3 bout-durations). POMS scores and technical performance data were collected during each bout of SSGs. The data demonstrated that the continuous-bout-duration (1 × 12 min) of 4vs4 and 3vs3 SSGs was characterized by a significant decrease in total mood disturbance (TMD) compared to 2 × 6 min and 3 × 4 min (4vs4:p < 0.01; 3vs3:p < 0.001). Continuous bout duration showed a greater (p < 0.05) percentage of successful passes compared to 2 × 6 min (4vs4; d = 2.57 [very large] and 3vs3: d = 1.79 [large]) and 3 × 4 min (4vs4: d = 2.14 [very large] and 3vs3; d = 1.73 [large]). The percentage of successful tackles was only greater (p < 0.05) for 1 × 12 min in 4vs4 (2 × 6 min; d = 0.83 [moderate] and 3 × 4 min: d = 0.86 [moderate]) and successful duels in 3vs3 (2 × 6 min; d = 1.41 [large] and 3 × 4 min; d = 1.43 [large]). The bout durations in four- and three-a-side soccer games seem to influence behavioral and technical performance of the players. Therefore, coaches should consider longer continuous bouts when planning SSGs-based training to significantly decrease TMD and enhance technical-tactical performance in soccer SSGs.

10 Oral Health and Oral Health-Related Quality of Life in Professional Soccer Players in Southern Italy: A Cross-Sectional Study

Reference: Oral Health Prev Dent. 2025 Feb 18:23:107-114. doi: 10.3290/j.ohpd.c_1859.
Authors: Silvia Angelillo, Martina Ferrillo, Delfina Pacifico, Saverio Mirarchi, Leonzio Fortunato, Carmelo Nobile
Download link: https://www.quintessence-publishing.com/deu/en/article-download/5982235/oral-health-and-preventive-dentistry/2025/volume-23/oral-health-and-oral-health-related-quality-of-life-in-professional-soccer-players-in-southern-italy-a-cross-sectional-study
Summary: The aim was to evaluate the oral health of professional footballers and to investigate possible determinants of oral health as well as the self-reported impacts on well-being, quality of life (QoL), and performance. This cross-sectional study was carried out on professional soccer players of the Calabria region, Italy. The outcome measures were the following: DMFT (decayed, missing and filled permanent teeth), DMFS (decayed, missing and filled permanent teeth surfaces), BEWE (basic erosive wear examination), CPI (community periodontal index), CPITN (community periodontal index of treatment needs), Oral Health Impact Profile-14 (OHIP-14). One hundred and sixty footballers were recruited from seven clubs. The median age of the players was 25 years (19-39) years. The mean DMFT was 2.8 ± 2.9, and the multiple logistic regression analyses showed a positive association with frequent intake of drinks rich in sugar (OR = 3.69, 95% CI = 1.59-8.56) and sports drinks (OR = 3.73, 95% CI = 1.09-12.75). Dental erosions were present in 48.1% of footballers and periodontal diseases in 50%, with a positive association with frequent intake of energy drinks (OR = 2.86, 95% CI = 1.09-7.51). The OHIP-14 showed that 30.6% of participants reported having had pain in their teeth/mouth/dentures occasionally. Results from the present study showed that the oral health of professional soccer players in Southern Italy was poor, especially regarding caries, erosion, and periodontal diseases. Moreover, OHIP-14 showed an impact on oral health in soccer players‘ QoL, revealing that poor oral health negatively affected professional well-being and performance. Results suggest the need for prevention interventions for professional athletes.

11 Shoulder injuries in amateur soccer players. An exploratory cross-sectional survey

Reference: Phys Ther Sport. 2025 Feb 10:72:77-85. doi: 10.1016/j.ptsp.2025.02.004. Online ahead of print.
Authors: Paola Bagnoli, Francesco Ferrarello, Fabio Pini, Duccio Rossi, Matteo Paci
Summary: The aim was to investigate the prevalence, incidence of players reporting shoulder injuries in a non-probability sample of Italian amateur soccer players. We also wanted to explore the characteristics of injuries, predictive factors and differences between men’s and women’s leagues. Adult athletes playing on a first team of the Italian National Amateur Soccer League participated in this study. Period prevalence, incidence, and characteristics of players reporting shoulder injuries over a soccer season were used as outcome measures. Fifty-one out of 431 respondents reported shoulder injuries. The pooled period prevalence was 12.0% (95%CI [9, 15]), with an incidence of .46 (95%CI [.35, .60]) injured/1000 h of players exposure. Goalkeepers were more likely to be injured than outfield players (OR 5.15, 95%CI [2.27, 11.25]). The injury type stated was mainly contusion (n = 22, 43.1%). Among those reporting injuries, thirty-four (66.6%) respondents stated 0-7 days as time loss from sport activity, with no significant difference due to role (p=.161) Shoulder injuries have a relatively low impact on the participation of adult amateur players in soccer activities. Technical and medical staff need to monitor players after an injury to the shoulder in order to provide appropriate training, prevention of complications and educational programs.

12 Assessing Individual Running Demands in Position Games: A Comparison Between Official Matches and Different Task Sizes in Young Professional Soccer Players

Reference: Eur J Sport Sci. 2025 Mar;25(3):e12251. doi: 10.1002/ejsc.12251.
Authors: Jose A Asian-Clemente, Jose Vicente Beltran-Garrido, Bernardo Requena
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC11829704/pdf/EJSC-25-e12251.pdf
Summary: The objectives of this study were to compare external loads between matches and position games based on player roles and to evaluate the load disparities between matches and different position games, individually considering each position. Twenty-five players (age: 21.9 ± 1.9 years; height: 177.9 ± 5.2 cm; weight: 75.5 ± 4.8 kg) were evaluated during 37 official matches and 18 position games classified according to their pitch sizes: small, medium, and large (50.8 ± 6.6 m2, 80.5 ± 4.6 m2, and 115.9 ± 25.2 m2 relative area per player, respectively). Players were categorized as: central defenders (CD), fullbacks (FB), defensive midfielders (CM), offensive midfielders (OM), wide midfielders (WM), and forwards (F). Using GPS, various metrics were recorded: distance covered (DC), DC > 21 km·h-1, peak speed, maximum accelerations and decelerations, and lower and higher than 3 m·s-2 (Acc<3; Acc>3; Dec<3; and Dec>3, respectively). Variables were normalized per minute (except peak speed, maximum accelerations, and decelerations). In all positions, matches consistently exhibited higher DC > 21 km·h-1 (p < 0.01), peak speed (p < 0.01), ACC<3 (p ≤ 0.01), DEC<3 (p < 0.01), and maximum accelerations and decelerations (p < 0.01). Small and large formats showed the same disparities across all positions (p < 0.05), whereas in medium position games, this trend was observed exclusively among FB and F (p < 0.05). Position games displayed greater ACC>3 and DEC>3 than matches for certain player positions, but these depended on the size of the drill (p < 0.05). Position games present different external loads than matches, depending on the players‘ positions and the size of these tasks.

13 Comparative Analysis of U17, U20, and Senior Football Team Performances in the FIFA World Cup: From Youth to Senior Level

Reference: Int J Sports Physiol Perform. 2025 Feb 21:1-10. doi: 10.1123/ijspp.2024-0343. Online ahead of print.
Authors: Wonwoo Ju, Ryland Morgans, Jordan Webb, Rick Cost, José M Oliva-Lozano
Summary: This study aimed to investigate differences in match physical and technical/tactical performance of teams across different competitive levels in international soccer: FIFA Men’s World Cup Qatar 2022 (MWC), FIFA U20 World Cup Argentina 2023 (U20WC), and FIFA U17 World Cup Indonesia 2023 (U17WC). From a total of 168 games, 138 games were analyzed (N = 276 game observations) using an optical tracking system. On average, the U17WC teams exhibited reduced total running (3% less), high-intensity running (14%-16% less), and sprinting (18%-26% less) distance than the MWC and U20WC teams (P ≤ .0023; effect size [ES]: 0.8-1.5). The MWC teams displayed 4% to 5% higher accuracy in passing and executing line breaks (P ≤ .0188; ES: 0.6-0.7), along with increased offers to receive the ball (53%-118% more) and movements to receive the ball (44%-101% more), and received the ball (61%-137%) more often than the U20WC and U17WC teams (P < .001; ES: 1.1-2.1). Moreover, notable decreases in defensive pressure (-18% to -32%) and forced turnovers (-26% to -32%) were observed in the U17WC than other competitions (P ≤ .0001; ES: 0.8-2.2). Greater variability was observed among the U17WC teams in several metrics, including high-intensity/sprinting distances, attempts at goal, and receptions in the final third. These findings demonstrate that as the competitive level increases, so do the physical demands, advanced technical skills, and tactical fluidity/adaptability. However, caution should be exercised when interpreting match performance of younger age groups, as higher variability was evident in both physical and technical/tactical performance in matches.

14 Menstrual Phase and Postmatch Perceptual Recovery Responses for Naturally Menstruating Football Players

Reference: Int J Sports Physiol Perform. 2025 Feb 21:1-9. doi: 10.1123/ijspp.2024-0295. Online ahead of print.
Authors: Georgia A Brown, Hugh H K Fullagar, Rob Duffield
Summary: The aim was to explore the influence of menstrual phase on postmatch perceptual responses and the time course of recovery for professional footballers. Thirteen naturally menstruating footballers tracked their menstrual cycle and reported perceptual responses for up to 4 cycles. Menstrual phases were determined by calendar-based tracking and urinary hormone tests and classified as menstruation, follicular, or luteal. On match days (MDs) and the following 2 days (MD+1 and MD+2), players completed perceptual questionnaires on fatigue, soreness, stress, sleep, and perceived recovery status (PRS). Total high-speed running distance during matches was recorded using GPS devices to represent load. Data were analyzed using linear mixed models. Day × total high-speed running distance affected PRS (P < .001), total wellness (P < .001), fatigue (P = .047), soreness (P < .001), and stress (P = .044). Significant main effects were found for menstrual phase on PRS (P = .038), Day on stress (P = .034), and total high-speed running distance on soreness (P = .045). During the menstruation phase, moderate effect sizes (ES) existed for worse PRS on MD and MD+2 (P = .07-.28, ES > 0.51) and better sleep quality on MD+2 (P = .13, ES = 0.56). No significant differences between menstrual phases existed (P > .05), and all other ESs were trivial to small (ES < 0.50). All perceptual measures, except stress, differed significantly between days (P < .05), with differences based on match load and, to a lesser extent, menstrual phase. PRS may be worse during menstruation, although menstrual phase has limited association with postmatch perceptual responses. Variability in the recovery time course for perceptual measures exists between menstrual phases, but evidence for consistently impaired recovery time course in any phase was not evident.

15 Delayed effects of heavy resistance or ballistic priming on sprint and agility in elite U19 football

Reference: J Sports Med Phys Fitness. 2025 Feb 21. doi: 10.23736/S0022-4707.25.16223-3. Online ahead of print.
Authors: René B Jørgensen, Lars T Pedersen, Torben Nielsen, Heidi K Egebæk, Rasmus Jensen
Summary: In elite football, optimization of physical performance increases athlete performance. Sprint and change of directional performance can be improved by previously conducting a priming protocol. However, it is unknown if this priming-induced performance enhancement is long-lasting. Eighteen under 19 years old elite football players (mean ± standard deviation [SD] age: 17.8±0.8 years, height: 181±8 cm, body mass: 72±8 kg) with 34±6 months of strength training experience were tested in 30 m sprint and 505 agility without previous exercise (baseline) or 20 hours following a priming protocol consisting of heavy resistance (heavy) or ballistic (ballistic) training. Baseline testing was performed between 3 and 5pm and the effects of priming were tested between 10 and 11 am the day after training. Heavy consisted of 32 repetitions of 85% of 1RM in the back squat, and ballistic consisted of 35 repetitions of 40% of 1RM in the specialized jump squat. Compared to baseline, sprint was improved after 10 m with heavy and ballistic by 0.01 and 0.03 s, respectively (P<0.05), whereas only ballistic improved sprint after 5 m (0.03 s, P<0.05). There were no differences after 30 m sprint or in the agility test. Acceleration (i.e., 5 m sprint) is improved 20 hours after performing heavy resistance or ballistic priming exercise. Since these priming exercises can be performed on the previous day, coaches should consider incorporating these in their regular training and match plans.

16 Validity and Sensitivity of a Submaximal Fitness Test for Assessing Cardiorespiratory Fitness and Response to Preseason Training Load in Female Football Players

Reference: Int J Sports Physiol Perform. 2025 Feb 20:1-8. doi: 10.1123/ijspp.2024-0376. Online ahead of print.
Authors: Lachlan MacKenzie, Ric Lovell, Lana Atkinson, Daniel Naumovski, Tzlil Shushan
Summary: The aim was to evaluate the within-athlete sensitivity, validity, and dose-response relationships of exercise heart rate (HRex) from a submaximal fitness test (SMFT) as a proxy measure of cardiorespiratory fitness. This study follows an observational, repeated-measures design. Twenty-five trained female football players‘ training loads (GPS and HR metrics) were collected throughout an 8-week preseason period. A 4-minute continuous-fixed SMFT protocol was administered weekly to evaluate HRex. A running time-trial assessment was conducted in weeks 2 and 8 to calculate mean velocity (5-min-30-s time-trial mean velocity) as a proxy measure of cardiorespiratory fitness. SMFT HRex measurement properties were determined via within- and between-athletes correlations and linear mixed models. The overall preseason change in SMFT HRex derived from weekly repeated measures was -4.7% points (90% CIs, -3.9 to -5.6). The association between SMFT HRex and 5-minute-30-second time-trial mean velocity changes was large (-0.55), with 90% CIs ranging from negative moderate to negative very large magnitudes (-0.31 to -0.71). A 1% point decrease in SMFT HRex corresponded to an increase in 5-minute-30-second time-trial mean velocity of 0.13 (90% CIs, 0.03-0.24) km·h-1. Within-athlete correlations between training loads and SMFT HRex demonstrated moderate inverse relationships with external-load parameters (-0.39 to -0.47) and small inverse relationships with HR-based internal metrics (-0.25 to -0.29). Accumulated high- and very high-speed running throughout the entire preseason showed consistent inverse dose-response relationships with SMFT HRex (moderate and large, respectively), while all other load measures displayed unclear associations. SMFT HRex is a sensitive and valid tool to evaluate preseason cardiorespiratory-fitness changes in female football players.

17 Does accumulated physical load in different time windows affect hamstring injuries in elite football players?

Reference: Res Sports Med. 2025 Feb 20:1-13. doi: 10.1080/15438627.2025.2468799. Online ahead of print.
Authors: Marc Guitart-Trench, Javier Sanchez-Sanchez, Xavier Valle, Jorge Garcia-Unanue, Francesc Cos, Antonio Alonso-Callejo, Gil Rodas, Jose Luis Felipe
Summary: This study aims to investigate how accumulated training load over different time windows (7, 14, and 28 days) influences the incidence of hamstring injuries in elite football players. A descriptive and longitudinal study was developed in 343 players in three teams (2nd Team, U-19 team, and U-18 team) from the academy of an elite football club in Spanish La Liga that also competed in the Union of European Football Associations Champions League during four seasons, from 2017/18 to 2020/21. External load variables (total distance, high-speed running, accelerations, etc.) for training and competition have been studied considering the volume variables during three different time windows along the different seasons (7 days, 14 days, and 28 days). Results did not show differences in the shortest time windows (7- and 14-week periods), showing that strength and conditioning coaches should analyse longer periods of time and compare them to previous periods with the same length in order to improve workload management and reduce injury risk. It is important consider the accumulated load (chronic) in periods of 28 days to avoid an increase that generates a hamstring injury. The control of the training load in blocks of 28-day time windows seems essential to minimize the injury rate in football players.

18 Dietary simple sugar intake, metabolic indicators, markers of inflammation, and injury among semi-professional football players

Reference: Food Nutr Res. 2025 Jan 27:69. doi: 10.29219/fnr.v69.11036. eCollection 2025.
Authors: Jun Hou, Yuemei Cui, Jun Gao, Ming Rong
Summary: Dietary sugar intake has been implicated in the development of metabolic dysfunction, chronic inflammation, and immune dysfunction, contributing to the pathogenesis of various diseases. This study aimed to investigate the associations between dietary total simple sugar intake and glycemic markers, lipid profile, serum levels of high-sensitivity C-reactive protein (hs-CRP), and adenosine deaminase activity (ADA), among semi-professional football players. A cross-sectional study was conducted among 108 semi-professional football players. Dietary intake of simple sugars was assessed using validated dietary assessment tools, while serum levels of biochemical variables were measured using standard laboratory assays. Multinomial logistic regression analysis and partial correlation analysis were performed to examine the associations between dietary simple sugars and serum biomarkers, adjusting for confounders. Strong positive associations were observed between dietary total simple sugar intake and hs-CRP and ADA levels in multinomial regression analysis. Also, among individual assessment of dietary simple sugars, dietary fructose and glucose intake were positively correlated with serum hs-CRP levels (r = 0.484, P < 0.001 and r = 0.393, P < 0.001, respectively) and serum ADA levels (r = 0.233, P = 0.001 for glucose; r = 0.188, P = 0.01 for fructose). There was no other association between dietary simple sugar intake and metabolic parameters. Our findings highlight the significant impact of dietary sugar intake on inflammation, as reflected by serum hs-CRP and ADA levels. Strategies aimed at reducing sugar consumption may help mitigate inflammation and improve overall health outcomes. Further research is warranted to elucidate the underlying mechanisms and to explore potential therapeutic interventions targeting dietary sugar intake for the prevention and management of chronic diseases.

19 The squat jump and sprint force-velocity profiles of elite female football players are not influenced by the menstrual cycle phases and oral contraceptive use

Reference: Eur J Appl Physiol. 2025 Feb 18. doi: 10.1007/s00421-025-05723-3. Online ahead of print.
Authors: Jérémie Bouvier, Pierre-Hugues Igonin, Mélanie Boithias, Alexandre Fouré, Alain Belli, Nathalie Boisseau, Cyril Martin
Download link: https://link.springer.com/content/pdf/10.1007/s00421-025-05723-3.pdf
Summary: Force-velocity profiling is an excellent tool for training individualization, especially in sports with well-established physical preparation practices, such as football. However, it remains unclear whether menstrual cycle phases and oral contraceptive (OC) use influence the force-velocity profile. The aim of this study was to determine whether squat jump and sprint force-velocity profiles change throughout the menstrual cycle or during the use of OC in elite female football players. The vertical and horizontal force-velocity profiles of 21 female football players (11 eumenorrheic women and 10 OC users; mean age 26.0 ± 3.7 and 24.1 ± 1.6 years, respectively) were analysed using photocells and a radar device during loaded squat jumps and 40-m sprints. The cycle phase at each testing session was confirmed by measuring serum oestradiol and progesterone concentrations. The menstrual cycle and OC phases were not associated with changes in the force-velocity profile parameters (p > 0.05). Maximal vertical power and theoretical (ratio between the horizontal component of the ground reaction force and the corresponding resulting maximal force and theoretical maximal running velocity) and functional (time to complete a 40-m sprint) parameters of the horizontal force-velocity profile were higher in OC users than eumenorrheic women. The main finding of this study is that the force-velocity profile is not influenced by the menstrual cycle phases or OC use. The differences observed between eumenorrheic athletes and OC users require further investigation but are more likely attributed to individual variations rather than to a specific hormonal environment.

20 The effects of a 6-week sand- vs. Land-based jump training programme on frontal plane knee angle and jump performance in adolescent female football players

Reference: J Sports Sci. 2025 Feb 18:1-13. doi: 10.1080/02640414.2025.2465946. Online ahead of print.
Authors: Mark C Richardson, William Evans, Paul Chesterton, Matthew Wright
Summary: Our study investigated the effects of a six-week jump-training intervention (sand- vs land- based incorporated in a warmup), on frontal plane knee angle and jump performance of adolescent female football players. Fifty-six females were randomly allocated to either the SAND or LAND group. Thirty-nine females completed the programme twice weekly and were eligible for analysis. Two-dimensional frontal plane projection angle (FPPA), countermovement jump (CMJ) and reactive strength index (RSI) (10-5 repeated jump test) were measured 1-week pre- and post-intervention. Analysis of covariance was used to model post-intervention group differences. Compatibility curves were used to visualise parameter estimates alongside p- values, and surprisal (S) value transforms. Mean difference (−XX-) and compatibility intervals (CI) (95|75%) for FPPA for SAND vs. LAND were −XX- = 1.29° (-0.11 to 2.69°|0.49 to 2.10°) for the dominant limb, and −XX- = 1.80° (0.56 to 3.04°|1.09 to 2.51°)| for the non-dominant limb. Interval estimates for jump performance were imprecise and unclear. The data indicates that including a sand surface within a jump training intervention could be beneficial when aiming to improve knee control in asymptomatic adolescent female football players, with no apparent detriment to jumping performance.

21 Prediction of football injuries using GPS-based data in Iranian professional football players: a machine learning approach

Reference: Front Sports Act Living. 2025 Jan 31:7:1425180. doi: 10.3389/fspor.2025.1425180. eCollection 2025.
Authors: Reza Saberisani, Amir Hossein Barati, Mostafa Zarei, Paulo Santos, Armin Gorouhi, Luca Paolo Ardigò, Hadi Nobari
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC11825737/pdf/fspor-07-1425180.pdf
Summary: The study aims to assess and compare the predictive effectiveness of football-related injuries using external load data and a decision tree classification algorithm by unidimensional approach. The sample consisted of 25 players from one of the 16 teams participating in the Persian Gulf Pro League during the 2022–2023 season. Player injury data and raw GPS data from all training and competition sessions throughout the football league season were gathered (214 training sessions and 34 competition sessions). The acute-tochronic workload ratio was calculated separately for each variable using a ratio of 1:3 weeks. Finally, the decision tree algorithm with machine learning was utilised to assess the predictive power of injury occurrence based on the acute-to-chronic workload ratio. The results showed that the variable of the number of decelerations had the highest predictive power compared to other variables [area under the curve (AUC) = 0.91, recall = 87.5%, precision = 58.3%, accuracy = 94.7%]. Although none of the selected external load variables in this study had high predictive power (AUC > 0.95), due to the high predictive power of injury of the number of deceleration variables compared with other variables, the necessity of attention and management of this variable as a risk factor for injury occurrence is essential for preventing future injuries.

22 Training load and fitness monitoring in Czech football: coach practices and perspectives

Reference: Front Sports Act Living. 2025 Jan 31:7:1513573. doi: 10.3389/fspor.2025.1513573. eCollection 2025.
Authors: Dominik Bokůvka, Michal Hrubý, Kristýna Čuperková, Tomáš Vencúrik, Vitor Padinha, Ana Carolina Paludo
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC11825800/pdf/fspor-07-1513573.pdf
Summary: The study aimed to describe the practices and perspectives of Czech football coaches regarding the monitoring of players‘ training load and physical performance, with a focus on identifying key barriers and preferred sources of information. A total of 235 football coaches completed an online survey comprehending training load monitoring methods, physical performance assessments, barriers to implementation, and information sources. Among respondents, 93.7% reported monitoring training load, with training diaries (70%) being the most utilized method for external load measures and heart rate (45%) for internal load. Despite this, 42.7% of coaches did not monitor internal load and 21.7% did not conduct physical fitness evaluations. The most frequently reported barrier was a lack of resources (74.5%), though elite-level coaches (52.8%) and strength and conditioning coaches (75%) identified human resources as their primary limitation. Across all levels, the Football Association was the preferred source of information (61.7%). The findings highlight the predominance of traditional monitoring practices among the Czech football coaches, alongside with notable gaps in internal load tracking and fitness evaluation. The resource constraints remain a major barrier. Practical recommendations include promoting economical monitoring tools, such as RPE, and enhancing collaboration among stakeholders to improved monitoring strategies. The Football Association’s play a key role on support these efforts.

23 The effects of COVID-19 on professional football: Clinical management, player performance, and vaccination impact

Reference: J Sci Med Sport. 2025 Feb 5:S1440-2440(25)00034-9. doi: 10.1016/j.jsams.2025.01.015. Online ahead of print.
Authors: Elena Azzolini, Alberto Favaro, Francesco Colotta, Piero Volpi
Download link: https://www.jsams.org/action/showPdf?pii=S1440-2440%2825%2900034-9

24 Associations Between Match-Play Characteristics and Environmental Temperatures in 4 Professional Football Leagues

Reference: Eur J Sport Sci. 2025 Mar;25(3):e12256. doi: 10.1002/ejsc.12256.
Authors: Edgar Schwarz, Rob Duffield, Andrew Roman Novak, Dennis Alan Compton, Tim Meyer
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC11829705/pdf/EJSC-25-e12256.pdf
Summary: This study investigated the association between environmental temperature and match-play characteristics (shooting, passing, dribbling and defending) in four professional football leagues. Twenty-seven performance indicators (PI’s) were collated from 1585 matches from the German Bundesliga 1 and 2, Spanish La Liga and Australian A-League. Environmental data were obtained for dry-bulb temperature (T) and wet-bulb globe temperature (WBGT) retrospectively from public sources. For each league, linear regressions were used to determine relationships between PI’s and T and WBGT and linear mixed models were used to determine those associations across all four leagues. Individual leagues showed varying associations between a collection of PI’s and environmental measures. When combining the four leagues‘ match data, 8 of the 17 investigated parameters were associated with T and WBGT (p < 0.002). Passes, especially short passes, were reduced in higher T (-2.3 [-3.1 to -1.5] and p < 0.001) and WBGT (-3.1 [-4.0 to -2.1] and p < 0.001), alongside an increase in the success rate of passes (0.06 [0.02-0.09] and p ≤ 0.001). The number of passes into the opponent’s final third was reduced for both T (-0.18 [-0.25 to -0.05] and p = 0.001) and WBGT (-0.17 [-0.28 to-0.05] and p = 0.002), but the number of key passes leading to a shot or goal was not associated with T or WBGT (p ≥ 0.67). The number of touches, take-ons and turnovers were reduced in higher T and WBGT (all p < 0.001). Accordingly, in higher heat stress, match actions, especially those performed at high volumes, are reduced. Therefore, teams should expect a possibly altered match play and may consider adapting tactical or heat-mitigating strategies to counter these effects.