Background/Objectives: Physical literacy (PL) is globally recognized as a foundational determinant of health status in children, but the effects of interventions based on PL were rarely studied in preadolescent children. The aim of this quasi-experimental, school-based study was to evaluate the potential effects of a PL intervention delivered during regular school hours on physical fitness (PF), physical literacy (PL), and physical activity (PA) in children aged 9 to 11 years from southern Croatia. Methods: Participants were 125 preadolescents (57 girls), and were grouped into a control group (C = 70), and an experimental group (E, n = 55). The E group participated in a specific PL-focused education, integrated into regular physical education (PE) lessons as a 5–6 min substitute for standard PE content, over 12 weeks (36 PE classes in total). The C group participated in the standard PE curriculum. A pre–post–retention design was used, and the observed variables included anthropometrics (height, weight, BMI), PF (jumping power, abdominal strength, upper body strength, flexibility, mobility, and cardiovascular endurance), PL (evaluated by the PLAYself questionnaire), and indirectly measured PA (estimated via the PAQ-C questionnaire). Multivariate (MANOVA and univariate (ANOVA) analyses of variance for repeated measurements were used with time, gender, and group as the main effects, including their interactions. Results: MANOVA calculated for a set of PF variables revealed significant main effects for time (F = 1361, p < 0.001) and a significant time × group interaction (F = 2.98, p < 0.05). Univariate ANOVA indicated specific intervention effects for jumping power and abdominal strength, favoring the E group. No significant differential effects were observed for PL or PA. Conclusions: The study demonstrated small, but statistically significant, improvements in PF indicators among children exposed to the PL-based intervention. Notably, the intervention was conducted in authentic school settings using standard resources, supporting the ecological validity and real-world applicability of the findings.

Injuries in elite youth football may disrupt training continuity and long-term development, particularly during the post-peak height velocity (post-PHV) period when training and match demands increase. Therefore, the aim of this study was to determine injury incidence and describe injury patterns in elite U17 football players across six consecutive competitive seasons, including injury type, anatomical location, mechanism, recurrence, and severity. A prospective longitudinal injury-surveillance design was implemented in one elite football academy from 2016/2017 to 2021/2022. Injuries were recorded in the club’s medical database using the international consensus time-loss definition. Injury incidence per 1000 h was calculated for overall exposure, training, and matches, and injuries were analyzed by diagnosis, mechanism, recurrence, and severity. Across the study period, 331 injuries were recorded. Overall injury incidence was 6.95/1000 h, with markedly higher incidence in matches (20.61/1000 h) than training (5.82/1000 h). Seasonal incidence ranged from 4.49/1000 h in 2019/2020 to 9.31/1000 h in 2021/2022. The proportion of injured players ranged from 48% to 76% per season. The most frequent injuries were contusions and muscle cramps/DOMS, followed by ligament injuries, tendinosis, and muscle ruptures. Knee, thigh, ankle, and hip/groin were the most affected regions. Most diagnoses showed a predominantly non-contact pattern. These findings support targeted prevention and load-management strategies in elite youth football.

Background and Study Aim. Although physical activity (PA) is an important determinant of physical fitness (PF) in children, studies have rarely examined the associations between PA and PF in early school-age children within narrow age spans. The aim of this study was to evaluate the associations between different intensities of PA and various indices of PF in children aged 9 -11 years. Material and Methods. The participants were 121 children aged 9 - 11 years (49 girls) who were tested for PF (anthropometrics, aerobic endurance, upper body and abdominal strength, jumping power, mobility and flexibility), and the PA was directly measured via GeneActiv triaxial accelerometers. A t test was used to define differences between sexes, while Pearson’s correlations between PA variables and PF indices and multiple regressions for PF criteria were used to calculate sex stratification. Results. Compared with girls, boys achieved better results in terms of jumping power capacity, upper body strength, and aerobic endurance, and they had a higher number of steps taken per day, and a higher amount of vigorous PA per day (all p < 0.05). The girls achieved better results in terms of flexibility and mobility. Correlations between PA-intensities and PF were weak to moderate. Multiple regression calculations revealed that vigorous PA was a significant predictor of jumping power, upper body strength, and aerobic endurance in boys (16%, 20%, and 13% of the explained variance, respectively) and jumping power in girls (18% of the explained variance). Moderate PA was a significant partial regressor of aerobic endurance in girls (13% of the explained variance). Conclusions. Tailoring physical-education curricula to gender-specific PA responses and expanding PF assessments can enhance student engagement, optimize fitness outcomes, and improve the overall effectiveness of physical education programs.

Long-term injury surveillance in professional football is essential for understanding temporal changes in injury patterns. However, prospective studies spanning multiple consecutive seasons within the same professional club remain scarce. This study aimed to investigate injury epidemiology, temporal trends, and injury characteristics over nine consecutive seasons in an elite Croatian professional football club. This retrospective longitudinal study over nine competitive seasons (2015/16–2023/24) included 167 male players participating in the professional first-team environment from a single professional football club, contributing a total of 382 player-seasons across nine consecutive seasons. A total of 749 time-loss injuries were recorded according to the FIFA Medical Assessment and Research Centre (F-MARC) consensus recommendations. Temporal trends were evaluated using Joinpoint regression, while injury characteristics, anatomical distribution, tissue involvement, and injury burden were analysed descriptively. Overall injury incidence averaged 12.66 injuries per 1000 h of exposure (95% CI: 11.77–13.60), with substantially higher incidence during matches (50.13 injuries/1000 h) than training (7.97 injuries/1000 h). Joinpoint regression identified a non-significant annual decline in injury incidence before the COVID-19 season (2019/2020) (APC = −9.66%), followed by a non-significant increase thereafter (APC = 4.88%). At least one injury was recorded in 295 player-seasons, corresponding to 77.2% of all eligible player-seasons. More than 80% of all injuries involved the lower extremities, while muscle injuries accounted for almost half of all recorded injuries. Functional muscle disorders were the most frequent injury type, whereas meniscal and articular cartilage injuries were associated with the highest mean time loss per injury. The predominance of lower-limb muscle injuries, together with the substantial burden associated with less frequent intra-articular knee injuries, highlights key priorities for injury prevention in professional football. Long-term surveillance within the same club provides valuable insights into evolving injury patterns and supports the development of targeted strategies to maximise player availability.