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 Comparative analysis of automated foul detection in football using deep learning architectures

Reference: Sci Rep. 2025 Apr 24;15(1):14236. doi: 10.1038/s41598-025-96945-0.
Authors: Abdallah Rabee, Zakaria Anwar, Ahmed AbdelMoety, Ahmed Abdelsallam, Mahmoud Ali
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12022285/pdf/41598_2025_Article_96945.pdf
Summary: Automated foul detection in football represents a challenging task due to the dynamic nature of the game, the variability in player movements, and the ambiguity in differentiating fouls from regular physical contact. This study presents a comprehensive comparative evaluation of eight state-of-the-art Deep Learning (DL) architectures – EfficientNetV2, ResNet50, VGG16, Xception, InceptionV3, MobileNetV2, InceptionResNetV2, and DenseNet121 – applied to the task of automated foul detection in football. The models were trained and evaluated using a curated dataset comprising 7000 images, which was split into 70% for training (4,900 images), 20% for validation (1,400 images), and 10% for testing (700 images). To ensure fair evaluation, the test set was balanced to contain 350 images depicting foul events and 350 images representing non-foul scenarios, although perfect balance was subject to class distribution constraints. Performance was assessed across multiple metrics, including test accuracy, precision, recall, F1-score, and Area Under the Receiver Operating Characteristic Curve (AUC). The results demonstrate that InceptionResNetV2 achieved the highest test accuracy of 87.57% and a strong F1-score of 0.8966, closely followed by DenseNet121, which attained the highest precision of 0.9786 and an AUC of 0.9641, indicating superior discriminatory power. Lightweight models such as MobileNetV2 also performed competitively, highlighting their potential for real-time deployment. The findings highlight the strengths and trade-offs between model complexity, accuracy, and generalizability, underscoring the viability of integrating DL architectures into existing football officiating systems, such as the Video Assistant Referee (VAR). Furthermore, the study emphasizes the importance of model explainability through techniques such as Gradient-weighted Class Activation Mapping++ (GradCAM++), ensuring that automated decisions can be accompanied by interpretable visual evidence. This comparative evaluation serves as a foundation for future research aimed at enhancing real-time foul detection through multimodal data fusion, temporal modeling, and improved domain adaptation techniques.

2 A scoping review of the research supporting coaching practice in women’s football – as the game grows the research strives to keep up

Reference: Sci Med Footb. 2025 Apr 24:1-10. doi: 10.1080/24733938.2025.2488525. Online ahead of print.
Authors: Claire Mulvenna, Nic Evans, Abbe Brady, Alan McCall, Naomi Datson, Stacey Emmonds, Katrine Okholm Kryger
Summary: The aim of this study was to scope the available peer-reviewed literature on competitive women’s football, identifying and mapping the current research on supporting coaching practice in women’s football. The study reviewed all women’s football-related studies scoped by Okholm Kryger et al. (2021) for their relevance to coaching in women’s football. Additionally, an updated search was performed from PubMed (1966-2023), PsycINFO (1967-2023), Web of Science (1900-2023), Scopus (1788-2023), SPORTDiscus (1892-2023) on 7 December 2023. The author, journal, title, and abstract of all included studies were scoped. Information extracted during the scoping process included: the population, playing level, age group, environment, study type, and geographical location of the research. A total of 373 articles were scoped. The publication topic most frequently researched was Performance Analysis – Physical (20%), followed by Performance Analysis – Technical/Tactical (18%) and Maturation/Talent Identification (13%). Most studies were focused on coaching senior players (n = 207, 55%) and elite football (n = 189, 51%). Despite the volume of research growing each year, it is noticeable that there are gaps in the research. Five topics only had a single figure number of articles (Teaching and Learning Strategies, Coach Education/Development, Socio-Cultural Experience’s of Coaching, Coaching Philosophy, and Responsibilities/Role in Football). At present given there is a particular emphasis on certain playing levels, playing populations, and research topics, there is a dearth of information in certain areas. As such, researchers should work to ensure there is greater thematic depth as well as an increased volume of research in women’s football.

3 Perceptions of Elite Young Male Football Players Regarding Injury Risk Factors and Prevention Strategies

Reference: J Sport Rehabil. 2025 Apr 23:1-6. doi: 10.1123/jsr.2024-0379. Online ahead of print.
Authors: Roberto Carlos Rebolledo-Cobos, Carlos Rolong-Donado, Bruno Manfredini Baroni
Summary: Football players aged 15-20 years experience injury incidence rates similar to those of professionals, with players injured in this age group being significantly less likely to reach the professional level. Understanding the factors that influence young footballers‘ acceptance, adoption, and compliance with injury prevention programs is crucial. Therefore, this study aimed to describe the perceptions of male football players from premier league academies regarding injury risk factors and prevention strategies. An online survey was used to explore perceptions of injury risk factors and prevention strategies among young football players (under-17 and under-20 teams) from premier league academies. A total of 504 footballers (mean age: 18 [2] y) across 9 academies in 8 different cities participated in this study. No risk factor was elected as very important by at least half of participants. The top 5 injury risk factors elected by players were „poor hydration,“ „inadequate warm-up,“ „poor rest/sleep,“ „inadequate diet,“ and „poor strength/power.“ At least 1 quarter of participants considered „genetics,“ „advanced age,“ „attention level,“ „wheatear conditions,“ and „alcohol consumption“ as irrelevant factors for injury. There was no consensus for any prevention strategy. Fourteen strategies were ranked as efficient by at least 3 quarters of participants. The top 5 prevention strategies elected by players were „warm-up before training/matches,“ „functional training,“ „hydration before and during training/matches,“ „flexibility training,“ and „workload monitoring.“ Lower than a half of participants endorsed „ankle braces“ and „thermal shorts“ for injury prevention. The results of this study offer valuable insights into the perceptions of elite young football players regarding injury risk factors and the effectiveness of preventive strategies. These perceptions are essential for understanding how athletes view injury prevention approaches in their daily routines.

4 Balancing economic and social results in football clubs: evidence of fans‘ perceptions in the Colombian context

Reference: Front Sports Act Living. 2025 Apr 7:7:1541829. doi: 10.3389/fspor.2025.1541829. eCollection 2025.
Authors: Juan Alejandro Hernández-Hernández, Abraham Londoño-Pineda, Robert Ng-Henao, Juan Lucas Macías-Franco, Jose Alejandro Cano
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12009807/pdf/fspor-07-1541829.pdf
Summary: Fans are not only loyal, but also powerful, and could therefore exert pressure on football club managers. This study examines the influence of fan-generated pressure on the economic and social sustainability outcomes of football clubs in Colombia, highlighting the role of active and non-active fan typologies. Using a conceptual framework rooted in stakeholder theory, we developed and tested a structural equation model (SEM) based on Colombian football fans. Results show that active fans, defined as direct or indirect followers, prioritize high-performing players and coaches and significantly influence economic outcomes through merchandising and broadcasting rights. Conversely, non-active fans, including passive and potential supporters, emphasize player stability and club goodwill. These findings highlight that fan pressure, shaped by sporting identity and performance expectations, serves as a critical lever for value co-creation and sustainability.

5 The mediatory role of challenge and threat in the relationship between positive thinking skills and perception of excellent performance: a study on football players

Reference: Front Psychol. 2025 Apr 7:16:1513146. doi: 10.3389/fpsyg.2025.1513146. eCollection 2025.
Authors: Osman Pepe, Mustafa Can Koc, Cihan Ayhan, Laurentiu-Gabriel Talaghir, Cristina-Corina Bentea
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12009868/pdf/fpsyg-16-1513146.pdf
Summary: The present study aims to examine the mediating role of challenge and threat between positive thinking skills and perception of excellent performance in football players competing in the regional amateur league, which is referred to as a semi-professional league in Turkey. The study population consisted of football players competing in regional amateur leagues in the 2023-2024 season, and the sample consisted of 388 athletes selected using the simple random method. In addition to the demographic information form developed by the researcher, the Positive Thinking Skills Scale, the Challenge and Threat in Sport Scale and the Performance Perfectionism Scale for Sport were applied to the participants. The data were analyzed digitally through the SPSS 25 package program. The Pearson Correlation analysis was used to determine the correlations between the variables and a regression analysis of the indirect effect approach based on the Bootstrap method through PROCESS v4.2 macro was used to determine the mediating effect of challenge and threat in the relationship between positive thinking and perception of excellent performance. PROCESS Macro Model Option 4 developed by Hayes was used to examine the mediating effect. While conducting this analysis, the 5,000 resampling option was selected in the Bootstrap method. The study found that positive thinking had a positive, moderate, and statistically significant effect on the perception of challenge (a = 0.439, p < 0.01) and excellent performance (c‘ = 0.484, p < 0.001), with approximately 32% of the variance in challenge explained by positive thinking (R 2 = 0.319, p < 0.01). Additionally, challenge played a mediating role. Positive thinking also had a negative, moderate effect on threat (a = -0.425, p < 0.01), explaining 7% of the variance in threat (R 2 = 0.070, p < 0.01). However, the threat had a negative and low-level impact on the perception of excellent performance (b = -0.244, p < 0.001). In conclusion, it was found that the positive thinking skills of the football players positively affected their perceptions of excellent performance, and the feelings of challenge and threat they experienced on the field played a mediating role in the relationship between these positive thinking skills and perceptions of excellent performance.

6 Caregivers nutrition knowledge and perspectives on the enablers and barriers to nutrition provision for male academy football players

Reference: J Int Soc Sports Nutr. 2025 Dec;22(1):2495879. doi: 10.1080/15502783.2025.2495879. Epub 2025 Apr 21.
Authors: Matthew Cole, Jennie L Carter, Frances Brooks, Charlie J Roberts
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12016246/pdf/RSSN_22_2495879.pdf
Summary: The assessment of nutrition knowledge, alongside the enablers and barriers to optimal dietary intake, in youth football players has previously been documented. However, there is comparatively little research on either of these within parents or host families, which is of value to understand given the vital role that these stakeholders play as the primary food provider to young football players. Thus, the purpose of this study was to assess the nutrition knowledge of these caregivers and explore their perceptions of the barriers and enablers to nutrition provision for male academy football players. A validated 35-item online questionnaire (A-NSKQ) was completed by 30 parents and 31 host family providers of youth academy football players from 16 different professional football clubs in England. The questionnaire consisted of 35 questions (total), 11 of which focussed on the assessment of general nutrition knowledge (GNK) and the remaining 24 assessed sports nutrition knowledge (SNK). Scores are presented as a percentage for total and each sub-section (GNK & SNK) and classified by the following rating: „poor“ (0-49%); „average“ (50-65%); „good“ (66-75%); and „excellent“ knowledge (76-100%). Differences in Total, GNK and SNK were compared between parents and host families using Independent-samples t-tests, with the alpha value set at p < 0.05 for all tests. A series of focus groups was also conducted with six parents and twelve host family representatives from four clubs to explore their perspectives of the enablers and barriers to providing nutrition support to youth football players. Thematic analysis was used to interpret the data. Host family providers demonstrated significantly better total nutrition knowledge than Parents (49.95 ± 11.64% vs. p = 42.67 ± 14.43%; p = 0.035), although the knowledge of both groups is classed as „poor.“ For the sub-sections of GNK & SNK, GNK was considered „average“ and significantly better than SNK, which was classed as „poor“ (GNK = 58.12 ± 16.87% vs. SNK = 40.98 ± 14.91%; p < 0.001). Host family providers reported significantly better SNK than parents (44.89 ± 13.21% vs. 36.94 ± 15.69%; p = 0.037) whilst no significant differences were observed in GNK between groups (61.00 ± 15.07% vs. 55.15 ± 18.33%; p = 0.180). Three key themes were generated relating to the caregivers‘ perceptions of the barriers and enablers to their food provision: 1) Club Support and Communication; 2) Time and Financial Resources; 3) Player-specific Characteristics. These findings suggest a clear need for football clubs to educate caregivers in the fundamental principles of healthy nutrition and football-specific nutrition requirements and encourage clubs to develop initiatives to better support caregivers in helping to young players to meet their dietary requirements.

7 Winning determinants between top and second division in Chinese professional football leagues: an interpretable machine learning approach

Reference: BMC Sports Sci Med Rehabil. 2025 Apr 21;17(1):86. doi: 10.1186/s13102-025-01130-5.
Authors: Bo Yuan, Jiaxuan Zhu, Pengyu Pan, Dingmeng Ren, Zheng Liang, Honglin Song, Tianbiao Liu
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12010637/pdf/13102_2025_Article_1130.pdf
Summary: This study investigated the impact of winning determinants in two professional soccer leagues. The sample was composed of 1,440 Chinese Super Football League (CSL) and Chinese Football Association China League (CFACL) matches (CSL matches = 720; CFACL matches = 720) during the 2017-2019 seasons. The study employed eXtreme Gradient Boosting (XGBoost) to assess the importance of 25 indicators exhibiting significant differences (p < 0.05) in their association with match outcomes, and the SHapley Additive explanations (SHAP) was utilized to interpret these findings. The results showed that scoring performance indicators, such as Shots On Target Inside Box (SOTIB), Shots, and Shots On Target (SOT), significantly influenced outcomes in both the CSL ([Formula: see text]=37.854%) and CFACL ([Formula: see text]=38.934%), with SOTIB being the most impactful. Additionally, this study found that defensive feature clearances were highly influential in both leagues, ranking second only to SOTIB of variable importance. Meanwhile, defensive feature fouls were a more significant factor in determining match outcomes in the CFACL than in the CSL. In both the CSL and CFACL, players must prioritize precision in shooting within the penalty area rather than merely increasing the frequency of shots. For CFACL teams, if consistent high-quality passing is unattainable, effective use of set pieces (e.g., free kicks) could serve as an alternative strategy to organize attacks. These findings can assist coaches in formulating tailored tactical strategies suited to the distinct demands of each league level.

8 Deep learning-based recognition model of football player’s technical action behavior using PCA-LBP algorithm

Reference: Sci Rep. 2025 Apr 21;15(1):13788. doi: 10.1038/s41598-025-94732-5.
Authors: Hongtao Chen, Zhengbai Lin, Quan Xu
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12012089/pdf/41598_2025_Article_94732.pdf
Summary: Football is a sport that requires sportsmen to have both physical strength and physical features. It must consider the distinctions between individuals and then provide targeted training. Football players can perform better on the field with targeted scientific training, but scientific training is based on identifying football players‘ technical actions and behaviors. Deep learning allows machines to emulate the behavior of humans, like sight, hearing, and thought. It solves a wide range of complicated pattern recognition issues. The deep learning procedure, in particular, is distinctive in its capacity to recognize images with great precision and offers technical assistance for analyzing and recognizing football players‘ behavior actions. However, traditional football action recognition mainly uses the standard local binary pattern (LBP) for recognition. In image recognition, problems include the high dimension of football technical action recognition data and inaccurate recognition. Principal component analysis (PCA) can be used to perform dimensionality reduction analysis on the technical action behavior of football players to reduce the amount of calculation in the process of technical action recognition. This paper compared and analyzed football players‘ technical action behavior recognition based on the PCA-LBP algorithm and the traditional LBP recognition. The data comparing the two algorithms are based on data from 200 football players at a football match in 2020. This paper mainly counts the specific stadium information of football players and the data samples of football technical action recognition. In addition, it uses the four technical actions of kicking, dribbling, stopping, and fake action as indicators to evaluate the accuracy of technical action recognition. The experimental results showed that the recognition accuracy of the PCA-LBP algorithm is 2% higher than that of the LBP algorithm when the number of kicking action recognition is 50 times. When the number of recognition times was 300, the recognition accuracy of the PCA-LBP algorithm was 24% higher than that of the LBP algorithm. The PCA-LBP algorithm also has higher recognition accuracy when comparing dribbling, stopping, and fake action. Therefore, using PCA to decrease the dimension of the LBP algorithm can enhance the accuracy of the recognition of the technical action behavior of football players.

9 Effect of match load on perceived wellness in highly trained female football players

Reference: PLoS One. 2025 Apr 21;20(4):e0321505. doi: 10.1371/journal.pone.0321505. eCollection 2025.
Authors: Ivan Baptista, Andreas Alexandersen, Andreas K Winther, Dag Johansen, Svein Arne Pettersen
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12011230/pdf/pone.0321505.pdf
Summary: Exposure to match loads significantly affects physiological and psychological indicators and, consequently, players‘ wellness. However, this information is still scarce in women’s football. Therefore, the aims of this study were twofold: a) to compare the wellness variation from matchday (MD) to two days post-match (MD+2); b) and to analyse the correlations between the players‘ external load on MD and the self-reported wellness on the day after the match (MD+1) and MD+2. This retrospective cohort study included data from 22 weeks and 33 official matches from 18 professional and semi-professional female football players competing in the Norwegian top-tier. Signals for total distance, high-speed running distance (>16 km/h-1), sprint distance (>20 km/h-1), acceleration distance, and number of sprints were collected using a Global Positioning System. Sleep duration and four wellness subsets were included in this study: sleep quality, delayed onset muscular soreness, fatigue and stress levels. Individual models were run using the respective wellness variable as the dependent variable, with matchday as a predictor. Data was modelled using cumulative link regression models. The model allowed random slopes for subjects to account for repeated measurements. Correlation analysis was computed using Spearman’s rank correlations. Our results from the cumulative link regression model suggest that fatigue increased on MD+1 (Estimate: 1.30; SE=0.16; p<0.001) and remained elevated on MD+2 (Estimate: 0.75; SE=0.15; p<0.001), when compared to MD. Sleep quality decreased on MD+1 (Estimate: -0.72; SE=0.14; p<0.001). Sleep duration decreased on MD+1 (Estimate: -0.70; SE=0.13; p<0.001) and on MD+2 (Estimate: -0.61; SE=0.13; p<0.001). Moderate correlations were observed on MD+2 between sleep duration and acceleration distance (0.32, p<0.001) and high-speed running distance (0.30, p<0.001). Competitive matches are associated with a disruption in the stability of the players‘ sleep patterns and wellness. The results also suggest that univariate external load measures may not be strong enough to predict the players‘ wellness status variation in the days following matches.

10 On-field kinematics of cut maneuvers in football players: Are wearable sensors reliable for assessing anterior cruciate ligament injury risk?

Reference: J Sports Sci. 2025 Apr 20:1-11. doi: 10.1080/02640414.2025.2493012. Online ahead of print.
Authors: Stefano Di Paolo, Alli Gokeler, Anne Benjaminse, Stefano Zaffagnini, Laura Bragonzoni
Download link: https://www.tandfonline.com/doi/epdf/10.1080/02640414.2025.2493012?needAccess=true
Summary: The aim of the present study was to present the reliability and normative values of wearable inertial sensors kinematics during football-specific cut maneuver tasks collected on the football field for assessing anterior cruciate ligament (ACL) injury risk. Forty-seven academy football players (age 15.9 ± 2.4 years, female n = 20) performed a planned 90° change of direction within the Agility T-test and unplanned football-specific changes of direction (FS deceiving action). Kinematics was collected through eight wearable inertial sensors (100 hz, MTw Awinda, Movella). Intraclass correlation coefficient and Root Mean Square Error were used to inspect test-retest and side-to-side reliability of peak and waveform kinematics. Normative kinematics was compared between male and female players (t-test with Cohen’s d, p < 0.05). Test-retest reliability was moderate-to-excellent in most of the parameters (r=0.40-0.92). Side-to-side reliability was worse than test-retest (both movement tasks). Female players showed worse movement quality than males with greater peak values on the frontal and transverse planes at the knee, pelvis and trunk and smaller knee and trunk flexion (d = 0.50-1.1 in Agility T-test, = 0.39-0.73 in FS deceiving action). The on-field cut maneuver kinematics by wearable sensors demonstrated sufficient reliability for most joints. Reliability and normative values might help to objectify ACL injury prevention programs in football academies.

11 Does running performance relate to the market value of elite male soccer players? A case study from the FIFA world cup

Reference: BMC Sports Sci Med Rehabil. 2025 May 2;17(1):109. doi: 10.1186/s13102-025-01162-x.
Authors: Abdullah Kılcı, Muhammed Emin Koç, Hülya Binokay, Ali Erdoğan, Okan Kamiş, Rafael Oliveira
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12046752/pdf/13102_2025_Article_1162.pdf
Summary: The study main aim was to investigate: the relationship between running performances and market values of soccer players playing in the 2022 FIFA World Cup, by playing position and all players; the comparisons by playing position; to analyse the relationship between running metrics and market values of the highest and lowest players ranked players. The relationship between running metrics and market values of 306 soccer players who participated in the tournament and played full time, as well as the 40 players with the highest (n = 20) and lowest (n = 20) market values was analysed. Overall, there was a very weak correlation between market values and total distance (r = 0.149), zone 3 (r = 0.153), zone 4 (r = 0.139), zone 5 (r = 0.160), high-speed runs (r = 0.132), sprints (r = 0.147), and top speed (r = 0.194) for all players (p < 0.05). Defenders showed very weak positive correlation between market values and top speed (r = 0.155, p < 0.05). Midfielders showed weak positive correlations between market values and zone 4 (r = 0.302, p < 0.05) and zone 5 (r = 0.369, p < 0.001), sprints (r = 0.367, p < 0.001), and top speed (r = 0.304, p < 0.05). Forwards showed no correlations (p > 0.05). While there is no significant correlation between running metrics and market value for players with the lowest market value (p > 0.05), there was a moderate negative correlation between total distance (r=-0.577) and zone 2 (r=-0.612) for the 20 players with the highest market value (p < 0.05). Moreover, there was a weak correlation with zone 5 (r = 0.450) and a moderate correlation with the top speed values (r = 0.596) (p < 0.05). Weak correlations between soccer players‘ running performance and market values suggest that different running thresholds are important metrics, although other factors (e.g., technical skill, age, national and team club) may influence this relationship. In conclusion, since coaches and scouts aim to recruit relatively talented players within the limits of their budgets, selecting athletes with high aerobic and anaerobic performance, particularly those with a strong high-intensity running profile, can contribute to team success and potentially generate high transfer revenues in the future.

12 Spatiotemporal and kinetic characteristics during maximal sprint running in fast running soccer players

Reference: PLoS One. 2025 May 2;20(5):e0322216. doi: 10.1371/journal.pone.0322216. eCollection 2025.
Authors: Yohei Takai, Terumitsu Miyazaki, Norihide Sugisaki, Takaya Yoshimoto, Naotoshi Mitsukawa, Kai Kobayashi, Hiroyasu Tsuchie, Hiroaki Kanehisa
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12047830/pdf/pone.0322216.pdf
Summary: This study aimed to elucidate spatiotemporal and kinetic variables in fast-running soccer players in comparison with sprinters or slow-running soccer players. Sixty-seven male soccer players and 17 male sprinters (Sp) performed 60-m maximal effort sprint running. The soccer players were classified into three groups: high-speed (SOCHigh), medium-speed, and low-speed (SOCLow). The antero-posterior and vertical ground reaction forces were measured with a 50-m long force plates system at every step during the sprint. Step length and step frequency were also computed from the position of center of pressure, contact time, and flight time. During the initial acceleration phase, SOCHigh exhibited similar running speeds to Sp. This was attributed to a higher step frequency in SOCHigh compared to Sp, while net antero-posterior impulse was lower in the former than in the later. In the range of running speed from 7.5 m/s to 8.5 m/s, net antero-posterior impulse for SOCHigh was similar to that for Sp. At 9.0 m/s, SOCHigh exhibited a lower net antero-posterior impulse compared to Sp, primarily due to a reduced propulsive impulse. Additionally, vertical impulse during the braking phase was larger in SOCHigh compared to Sp, due to a longer braking time, while vertical impulse during the propulsive phase was smaller, due to a tendency for a reduced propulsive time and vertical force during the corresponding phase. Compared to SOCLow, SOCHigh exhibited higher step frequency through sprint running and longer step lengths from the 2nd acceleration phase to maximal speed phase. Additionally, net antero-posterior impulse at the same running speed was greater in SOCHigh compared to SOCLow. Vertical impulse was lower during the braking phase but higher during the propulsive phase in SOCHigh than in SOCLow. Thus, the sprint mechanics of SOCHigh is characterized by a similar ability of speed acquisition up to the 2nd acceleration as sprinters. However, at 9.0 m/s or over, SOCHigh exhibits a greater vertical impulse, leading to a lower step frequency.

13 The relative age effect and the relationship between biological maturity and athletic performance in Austrian elite youth soccer players

Reference: Front Sports Act Living. 2025 Apr 17:7:1583880. doi: 10.3389/fspor.2025.1583880. eCollection 2025.
Authors: Mirko Wenger, Robert Csapo
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12043890/pdf/fspor-07-1583880.pdf
Summary: Publications from recent years suggest that the biological developmental stage of underage athletes has a significant impact on their athletic performance. This scientific study is the first quantitative attempt in Austria to investigate the impact of the relative age effect and biological maturity on the physical performance of young elite soccer players. Birth data from a total of 98 male players in the U13 to U18 age groups of a first-division Austrian soccer club were collected. By measuring height, sitting height and body mass, the individual biological age was calculated using the Mirwald equation. The athletes underwent a standardized battery of tests, which included assessments of speed, strength and endurance. The results indicate a significant effect of the relative age effect on player selection in the U14 and U15 teams (p < .05), which diminishes with increasing player age. Compared to typical Austrian adolescents of similar age, U13, U14 and U15 players demonstrate a higher level of biological maturity (p < .05). Correlational analyses revealed that the maturity offset, reflecting the time before or after the greatest individual growth spurt, was positively related to eccentric hamstring strength (r = 0.82) and vertical jumping ability (r = 0.61) and positively related to sprint performance over 5, 10 and 20 m (0.62 < r < 0.69; all p ≤ .001). Biological maturity and the associated anthropometric adaptations are decisive for athletic performance. The study supports the notion that biologically more mature players achieve better athletic performance than less mature players, especially before the onset of puberty.

14 Passing-skill training vs. small-sided games for improvement of side-foot kick accuracy among youth female soccer players

Reference: Front Sports Act Living. 2025 Apr 17:7:1506563. doi: 10.3389/fspor.2025.1506563. eCollection 2025.
Authors: Tomas Carlsson, Joakim Broman, Jenny Isberg, Magnus Carlsson
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12043672/pdf/fspor-07-1506563.pdf
Summary: This study compared the effectiveness of a passing-skill training (PST) concept (theory lectures, passing-skill training, and external- and internal-focus feedback) and three-a-side small-sided games (SSG) on improving side-foot kick accuracy among youth female soccer players. Seventeen youth female soccer players (age: 12.7 ± 0.8 years) completed the pre-post-intervention study, where the pre- and post-tests included three 10-m passing accuracy tests with increasing level of complexity: (1) stationary ball with a fixed target (SBFT), (2) rolling ball with a fixed target (RBFT), and (3) rolling ball with a moving target (RBMT). Based on the pre-tests, the participants were matched into the PST group or the SSG group. The training consisted of nine 30-min sessions for both groups during a period of 4.5 weeks. During the intervention, the PST group significantly improved the side-foot kick accuracy across all three tests. In contrast, the SSG group showed no significant change in passing accuracy in either the RBFT test or the RBMT test; however, their side-foot kick accuracy was significantly reduced in the SBFT test. There were significant between-group differences in side-foot kick accuracy across all three tests after the intervention, where the PST group had a greater side-foot kick accuracy than the SSG group. In conclusion, results indicate that the PST concept significantly enhances passing accuracy across all tested variables, unlike SSG, suggesting PST’s superiority in technical skill development.

15 Preseason neuromuscular versus endurance training leads to greater improvements in isokinetic strength, muscle damage, and inflammation parameters in highly trained female soccer players

Reference: BMC Sports Sci Med Rehabil. 2025 Apr 30;17(1):107. doi: 10.1186/s13102-025-01154-x.
Authors: Ali Belamjahad, Claire Tourny, Anthony C Hackney, Nidhal Jebabli, Naoual Chariba, Fatiha Laziri, Ayoub Saeidi, Ismail Laher, Urs Granacher, Hassane Zouhal
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12042536/pdf/13102_2025_Article_1154.pdf
Summary: The preseason offers an opportunity to achieve an optimal level of physical fitness for the entire season. The question arises whether the training programs induce muscle damage and inflammatory processes which may have a negative impact on players‘ readiness at the beginning of the season. To examine the effects of a preseason neuromuscular training program (NMT) versus endurance training (ET) on measures of isokinetic strength, muscle damage, and blood parameters in female soccer players. Twenty-two highly trained female soccer players with a mean age of 17.0 ± 1.3 years were randomly assigned to a NMT (n = 11) or ET group (n = 11). NMT and ET programs lasted six weeks with three sessions per week, each 45-60 min. NMT included strength, power, linear sprint and change-of-direction speed, and dynamic stability exercises. ET comprised running, circuit drills, coordination, aerobic circuit, interval-training, speed-endurance exercises, and dynamic stretching. isokinetic knee flexor/extensor parameters (e.g., peak torque) were tested pre- and post-training. Blood samples were analyzed for muscle damage markers: creatine kinase (CK), lactate dehydrogenase (LDH), and inflammation markers: C-reactive protein (CRP), and interleukin-6 (IL-6). Significant group-by-time interactions were found for all isokinetic parameters (0.001 < p < 0.012, 1.35 < d < 4.17). Post-hoc tests revealed significant improvements following NMT but not ET (0.001 < p < 0.045, 0.81 < d < 2.46). Additionally, there were also significant group-by-time interactions for IL-6 (p = 0.005; d = 0.31), CK (p = 0.026; d = 1.0), and LDH (p < 0.003; d = 1.44). Variations in IL-6, CK, and LDH determined by post-hoc tests indicated decreases in NMT but not ET (IL-6: p = 0.005, d = 1.27; CK: p = 0.023, d = 1.01; LDH: p = 0.002, d = 1.42). Six weeks of preseason NMT produced larger improvements in isokinetic strength and less muscle damage and inflammation in highly-trained female soccer players compared to ET group.

16 The Effect of Pubertal Status on Post-activation Performance Enhancement in Young Soccer Players

Reference: Sports Med Int Open. 2025 Apr 22:9:a23583840. doi: 10.1055/a-2358-3840. eCollection 2025.
Authors: Renato Ferreira Estrella, Valmir Oliveira Silvino, Tatiane Ferraz, Joaquim Paulo Grava de Souza, Marcos Antonio Pereira Dos Santos, Danilo Marcelo Leite Prado
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12039887/pdf/10-1055-a-2358-3840.pdf
Summary: Post-activation performance enhancement (PAPE) occurs when performance improves after intense contractile stimulation. This study examined the effect of pubertal status on PAPE after a maximal cardiopulmonary exercise test (CPET) in 48 male soccer players aged 10-18 years. Additionally, we investigated the relationship between maximal aerobic speed (MAS) and lower limb strength. They were classified as pre-pubescent (n=13), pubescent (n=15), and post-pubescent (n=20). The participants performed three countermovement jumps (CMJ) before and after a maximal CPET. The PAPE was estimated by calculating the difference between pre- and post-exercise CMJ height at five minutes of recovery after CPET. The CPET was performed on a treadmill using a ramp protocol to determine the maximal oxygen consumption (VO 2 max) and MAS. CMJ height was significantly greater after the CPET for all groups. Post-pubescent participants had significantly greater PAPE than both pre-pubescents and pubescents. Pre-pubescents had significantly lower CMJ height, VO 2 max, and MAS compared to pubescent and post-pubescents. Finally, a positive relationship was observed between MAS and CMJ height. In conclusion, PAPE after maximal CPET was observed in all pubertal cohorts of young soccer players. However, it was greater in post-pubescent children. Finally, MAS was positively correlated with lower limbs strength.

17 Effects of plyometric training on jump, sprint, and change of direction performance in adolescent soccer player: A systematic review with meta-analysis

Reference: PLoS One. 2025 Apr 29;20(4):e0319548. doi: 10.1371/journal.pone.0319548. eCollection 2025.
Authors: Tianjing Zheng, Runzhou Kong, Xiaowen Liang, Zhilong Huang, Xicai Luo, Xuan Zhang, Yichao Xiao
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12040276/pdf/pone.0319548.pdf
Summary: Soccer requires a high level of physical fitness, particularly in jumping, sprinting, and change-of-direction (COD) performance. Plyometric training has been extensively studied in adult athletes, but its effects on these abilities in adolescent soccer players remain insufficiently evaluated. This systematic review with meta-analysis examined the effects of plyometric training on jump, sprint and COD performance in adolescent soccer player. Eligible randomized controlled trials were identified through searches of PubMed, Web of Science, Scopus, and SPORTDiscus databases, focusing solely on published studies. Study quality was assessed using the PEDro scale, and statistical analysis was conducted using Stata software to calculate the standardized mean difference (SMD) and 95% confidence intervals. Twenty studies comprising 28 randomized controlled trials with a total sample size of 796 participants were included. The results indicated that plyometric training significantly improved the jumping ability (SMD = 0.76, 95%CI: [0.59, 0.93]; moderate effect), sprinting ability (SMD = -0.45, 95%CI: [-0.57, -0.32]; small effect), and COD (SMD = -0.76, 95%CI: [-1.04, -0.47]; moderate effect) of adolescent soccer players. Plyometric training effectively enhances jumping, sprinting, and COD abilities in adolescent soccer players. Compared to soccer-specific training alone, PT demonstrated moderate improvements in jumping and COD performance and small improvements in sprinting ability. These findings highlight the importance of incorporating PT into routine soccer training regimens to develop explosive strength and agility in adolescent athletes.

18 Gray matter volume increase in the retrosplenial/posterior cingulate cortices of blind soccer players

Reference: Front Neurosci. 2025 Apr 14:19:1462481. doi: 10.3389/fnins.2025.1462481. eCollection 2025.
Authors: Tomoyo Morita, Eiichi Naito
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12034674/pdf/fnins-19-1462481.pdf
Summary: Individuals typically recognize where they are (localization) and in which direction they are heading (orientation) in a space using vision, and the retrosplenial/posterior cingulate cortices (RSC/PCC), parahippocampal cortex (PHC), and hippocampus (HP) have been shown to play crucial roles for these navigation-related functions. However, there is empirical evidence that top blind soccer players with long-term training can navigate on the court without vision. This study examined the potential changes in gray matter (GM) volume in the RSC/PCC, PHC, and HP in the brains of a leading and other blind soccer players. We collected structural magnetic resonance imaging (MRI) scans from six blind soccer players (including the world’s top player) and eight blind non-soccer players. Using voxel-based morphometry (single-case approach), we compared GM volume in each participant to that of 250 sighted participants (none of whom had ever played blind soccer). The world’s top blind soccer player had a significant increase in GM volume in the bilateral RSC/PCC compared to sighted participants. Two of the other five blind soccer players also showed a GM increase in the left RSC/PCC. However, this increase in GM volume was not observed in blind non-soccer players. Consequently, the probability of a significant GM increase in the RSC/PCC was significantly higher in the blind soccer group than in the blind non-soccer group. In contrast, no between-group differences were observed in the probability of a significant GM volume increase in the PHC and HP. This study, which unveiled the characteristics of the brains of the world’s top blind soccer player and other blind soccer players, demonstrates for the first time that blind soccer training, which requires navigation based on non-visual cues, may enlarge the human RSC/PCC. Moreover, the findings promote our understanding of the brains of visually-impaired persons playing blind soccer.

19 Analysis of Injury Epidemiology in Soccer Players in the 2019 Confederation of North, Central America and Caribbean Association Football Gold Cup as Reported by Team Physicians

Reference: Arthrosc Sports Med Rehabil. 2025 Jan 3;7(2):101074. doi: 10.1016/j.asmr.2024.101074. eCollection 2025 Apr.
Authors: Brian Forsythe, Derrick M Knapik, Daanish Khazi-Syed, Joshua Chang, Camden Bohn, Catherine Hand, Avinaash Korrapati, Ophelie Lavoie-Gagne, George Chiampas, Bert R Mandelbaum, Jorge Chahla
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12034059/pdf/main.pdf
Summary: The aim was to describe and characterize injuries reported in professional soccer athletes participating in the 2019 Confederation of North, Central America and Caribbean Association Football (CONCACAF) Gold Cup tournament. Data were collected from electronic medical reports submitted after each match of the 2019 CONCACAF Gold Cup tournament. Reports were generated from a 20-question online survey completed by team physicians from all 16 participating teams. For every recorded injury, a separate survey was completed by team physicians documenting athlete demographic characteristics, context of injury, injury characteristics, and expected time lost from injury. A total of 62 surveys were distributed, of which 80% (50 of 62) were collected for analysis. A total of 27 injuries (7%) were recorded among the 368 participating athletes. Injuries most frequently occurred during matches (92%, 24 of 27), with a significantly higher number of injuries recorded between the 61st and 75th minutes of play (P < .05). New injuries constituted 85% of all injuries (23 of 27), whereas 15% of injuries (4 of 27) were recorded as recurrences of prior injuries. Defenders had the highest number of injuries (41%, 11 of 27). Injuries to the lower extremities comprised 52% of all injuries (14 of 27), with thigh strains being the most common. During the 2019 CONCACAF Gold Cup, injuries were recorded in 7% of athletes (27 of 368), with 89% of injuries recorded as occurring during match play, primarily consisting of injuries involving strains to the thigh.

20 Analysis of Genu Varum in Young Male Professional Soccer Player

Reference: Orthop J Sports Med. 2025 Apr 18;13(4):23259671251330602. doi: 10.1177/23259671251330602. eCollection 2025 Apr.s
Authors: Femke Steffen, Tim Rolvien, Matthias Krause, Karsten Hollander, Tim Hoenig, Karl-Heinz Frosch, Götz H Welsch, Dimitris Dalos
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12035087/pdf/10.1177_23259671251330602.pdf
Summary: Bowlegs (Genu varum) are well-known leg axis deformities in adult soccer players and are associated with an increased risk of knee osteoarthritis. The time of onset of genu varum is unknown. The aim was to analyze the static and dynamic leg axis in young professional soccer players from childhood to adolescence. Leg axes of 168 male professional soccer players (336 legs) from 8 age groups (U12-U21) were analyzed. Static and dynamic mechanical femorotibial axis angles (MAAs) were determined using a noninvasive motion analysis system allowing both legs to be evaluated individually. Additionally, the intercondylar and intermalleolar distances were measured. Statistical analyses were performed using a linear mixed model including the variables of age, playing position, shooting leg, and body mass index (BMI). A significant increase in varus alignment for static and dynamic MAA was found with age. Players of the teams U17, U19, and U21 had significantly higher static MAAs (greater varus) compared with the youngest players (U12). The deviation in the dynamic MAA could be observed starting from the U15 onward. In all age groups, the dynamic MAA was significantly lower than the static MAA. No significant association was found for static or dynamic MAA with BMI, playing position, or shooting leg. In this study, the degree of static and dynamic varus alignment was significantly associated with increasing age. On the basis of the study’s findings, it is believed that preventive training methods particularly focusing on vulnerable age groups should be tested for efficacy.

21 Factors Influencing Change of Direction Performance in Youth Soccer Players: Velocity-Time Profile Analysis of the Pro-Agility Test

Reference: J Strength Cond Res. 2025 Apr 29. doi: 10.1519/JSC.0000000000005116. Online ahead of print.
Authors: Hayato Nakamura, Daichi Yamashita, Daichi Nishiumi, Naoto Nakaichi, Norikazu Hirose
Summary: The purpose of this study was to assess factors influencing change of direction (COD) deficit (CODD) and total time completion (CODTT) in adolescent soccer players through velocity-time profile analysis of the Pro-Agility Test. We enrolled 71 junior high school male soccer players and measured the 20-m sprint time and CODTT of the Pro-Agility Test, calculating CODD by subtracting the 20-m sprint time from CODTT. In addition, 3-dimensional motion data were collected using a markerless motion capture system during the Pro-Agility Test. Each section (5 m in the first, 10 m in the second, and 5 m in the third) was divided into acceleration and deceleration phases based on center of mass (COM) velocity, which were further divided into early and late halves. The mean COM acceleration during the acceleration phase (Acc) and deceleration during the deceleration phase (Dec) were calculated. Stepwise multiple regression analysis was performed to identify phases affecting CODTT and CODD. Statistical significance was set at p < 0.05. Total time completion of a COD task was explained by the second early Acc (β = -0.500), second late Dec (β = 0.433), and 20-m sprint time (β = 0.226) (adjusted R2 = 0.858), whereas CODD was explained by the second late Dec (β = 0.561) and second early Acc (β = -0.271) (adjusted R2 = 0.459). Maturity offset significantly correlated with CODTT (r = -0.456) but not with CODD (r = -0.119). The results indicated that deceleration and reacceleration during the Pro-Agility Test can be evaluated in adolescents by combining CODTT and CODD.

22 Impact of 30-minute and 90-minute Naps on Aerobic and Anaerobic Intermittent Performance in Collegiate Soccer Players

Reference: Nat Sci Sleep. 2025 Apr 23:17:621-630. doi: 10.2147/NSS.S498173. eCollection 2025.
Authors: Anran Xu, Ning Wang, Yang Gao, Xiaotian Li
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12034280/pdf/nss-17-621.pdf
Summary: This study aims to investigate the effects of 30-minute and 90-minute naps on collegiate soccer players‘ aerobic and anaerobic performance following a normal night of sleep, and to compare the performance differences between the two nap durations. A total of 25 male collegiate soccer players (age: 20 ± 1 years, height: 180.4 ± 5.6 cm, weight: 72.1 ± 4.2 kg, BMI: 22.1 ± 2.2 kg·m⁻²) participated in the RAST and 30-15. Intermittent fitness test (IFT) under three conditions: no nap (N0), 30-minute nap (N30), and 90-minute nap (N90). Post-nap assessments showed significant improvements in peak power per weight (p = 0.007, η² = 0.13), minimum power per weight (p < 0.001, η² = 0.25), and average power per weight (p < 0.001, η² = 0.28) in the RAST test, with no notable differences between the N30 and N90 groups. Additionally, the fatigue index (FI) in the N90 group significantly decreased compared to N0 (p = 0.005, d = 0.86). Both N30 and N90 groups exhibited higher VIFT values than the N0 group (p < 0.001, η² = 0.23). However, no significant changes were noted in average heart rate (p = 0.198) or perceived exertion (RPE) (p = 0.376) during the 30-15 IFT after napping. Napping effectively enhances the aerobic and anaerobic performance of collegiate soccer players following a normal night of sleep. Implementing strategic napping may be beneficial for athletes seeking to optimize their performance before training or competition.

23 High-Load Strength Training Reduces Injury Incidence and Injury Burden and Improves Physical Fitness in Young Highly Trained Soccer Players

Reference: Sports Health. 2025 Apr 27:19417381251333417. doi: 10.1177/19417381251333417. Online ahead of print.
Authors: Roberto Durán-Custodio, Javier Yanci, Javier Raya-González, Marco Beato, Daniel Castillo
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC12037537/pdf/10.1177_19417381251333417.pdf
Summary: There is little available information on the reduction of injury incidence and injury burden after strength training programs. This study aimed to analyze the effects of a 12-week high-load strength training program on injury incidence, injury burden, and fitness in young, highly trained, soccer players. It was hypothesized that well-targeted high-load training focused on the gluteal and hamstring musculature could aid in injury prevention and increase physical fitness. Twenty players were assigned randomly to the experimental group (EG, n = 10 players), who performed a high-load strength training program, or to the control group (CG, n = 10 players), who performed only their usual soccer training. Injury incidence (injuries per 1000 hours exposure) and injury burden (days of absence per 1000 hours exposure) were recorded during the intervention, as well as the physical fitness attributes before and after the training program. A significant (P < 0.05) lower injury incidence was observed in the EG (CG, 11.34 vs EG, 1.31 injuries per 1000 hours of exposure) and a significant (P < 0.001) lower injury burden in the EG (CG, 304.66 versus EG, 19.72 days of absence per 1000 h of exposure). The analysis of covariance model revealed significant between-group differences favoring the EG, showing significantly greater improvements in jumping, change of direction ability, sprinting, and imbalance strength tests (P < 0.001; effect size, 3.02 to -7.23). This study demonstrated the beneficial effects of a 12-week high-load strength training program on injury incidence, injury burden and physical fitness, in highly trained soccer players.