Background. Functional asymmetries in youth football players represent significant performance limitations and injury risk factors requiring targeted intervention strategies. Elite youth athletes frequently demonstrate bilateral imbalances across multiple neuromuscular domains. Objective. This study evaluated the effectiveness of an individualized 8-week neuromuscular training program in reducing functional asymmetries among elite youth football players across different age categories (U16, U17, U18). Methods. This 8-week experimental intervention aimed to reduce functional asymmetries in balance, unilateral strength, and jump performance among elite youth footballers. Conducted in addition to their regular weekly schedule (five sessions, 8–10 hours football-specific practice + 2–3 hours strength and conditioning), the program comprised two 30–40 min neuromuscular sessions per week. Each session included four blocks: activation & mobility, unilateral strengthening, plyometrics & single-leg jumps, and balance & postural control. Progression was applied systematically through increased load, instability, movement complexity, and football-specific demands, following the principle of progressive overload. Individualization strategies targeted the weaker limb when interlimb differences exceeded 10%, with adjustments based on RPE, mid-term, and final assessments. Results. Significant reductions in functional asymmetries were observed across all variables and age groups. Y-Balance Test asymmetries decreased by 46-60%, Single Leg Hop Test asymmetries reduced by 39-46%, and quadriceps strength asymmetries diminished by 42-47%. Younger players (U16) demonstrated greater magnitude improvements compared to older athletes. Strong correlations existed between different asymmetry measures, supporting multidimensional assessment approaches. Effect sizes ranged from moderate to large across all variables. Conclusion. The individualized neuromuscular training intervention effectively reduced functional asymmetries in youth football players, with age-related response variations supporting developmentally appropriate program design for optimizing athletic performance and injury prevention.

Background: Exercise-induced cardiac remodelling results in electrocardiographic alterations that vary by sport and ethnicity. International screening criteria, derived primarily from Caucasian populations, may inadequately capture physiological variations in North African athletes. Aim: To establish electrocardiographic profiles of Moroccan university athletes using the Seattle International Criteria and to analyse sport-specific variations. Methods: This cross-sectional study enrolled 149 university athletes (79 male, 70 female, aged 18-25 years) from Hassan I University in Morocco, classified into endurance, mixed/team and strength/power sports. Standardised 12-lead electrocardiography was interpreted independently by two specialists. ANOVA and chi-square tests were used for statistical analysis, and effect sizes were reported. Results: Significant differences in heart rate between sports emerged (p < .001, η² = .124): endurance athletes showed lower rates (58.4 ± 11.2 bpm) compared to mixed/team athletes (65.1 ± 11.8 bpm) and strength/power athletes (68.9 ± 12.5 bpm). The prevalence of sinus bradycardia was higher in endurance athletes (47.5% vs. 27.0% in mixed/team and 25.0% in strength/power; p = .018). Training-related findings were frequent (34.9% sinus bradycardia overall), borderline findings occurred in 5.4-8.1% and abnormal findings were minimal (6.0%). Conclusions: Moroccan athletes demonstrate sport-specific electrocardiographic adaptations with lower abnormality rates than those reported in sub-Saharan African populations, suggesting North African heterogeneity. The findings challenge assumptions about continental generalisations and support region-specific regulatory frameworks rather than universally applicable criteria, especially among endurance athletes who show pronounced bradycardic adaptations.

Background. Functional asymmetries in youth soccer players represent an important biomechanical and neuromuscular phenomenon, acting both as adaptive mechanisms and as potential risk factors for injury. However, existing evidence remains fragmented regarding the effectiveness of technological and artificial intelligence (AI)–based approaches for their assessment across different populations. Purpose. This systematic review aimed to synthesize current methodologies and applications of technological tools and artificial intelligence used to assess functional asymmetries in youth soccer players. Methods. The review was conducted in accordance with PRISMA guidelines. A total of 418 records were identified through searches in Scopus, Web of Science, and PubMed, of which 28 studies met the inclusion criteria. Methodological quality was evaluated using standardized assessment tools. The included studies examined wearable technologies, biomechanical assessment systems, and AI-based analytical models for asymmetry detection and interpretation. Results. AI-based models demonstrated moderate predictive accuracy for injury risk, with reported values up to AUC = 0.70. Wearable inertial measurement units showed high ecological validity for on-field assessment of functional asymmetries. However, substantial heterogeneity was observed across studies in terms of asymmetry thresholds, outcome definitions, and analytical procedures, limiting cross-study comparability. A key finding was that strength asymmetries exceeding 15% were significantly associated with increased injury risk (p < 0.05), while such asymmetries did not consistently impair sprint performance, indicating context-dependent functional effects. Conclusions. The findings indicate that technological and AI-based approaches provide valuable tools for assessing functional asymmetries in youth soccer players, particularly when applied in ecologically valid settings. The integration of explainable AI with multimodal biomechanical data appears to be a promising direction for personalized monitoring and intervention strategies. Future research should prioritize standardized methodological reporting, harmonized asymmetry thresholds, and longitudinal study designs to improve comparability and clinical translatability of findings.

Background and Study Aim. Physical training is associated with cardiac electrical adaptations that may be reflected in electrocardiographic (ECG) characteristics. Although physical activity can be quantified in terms of both total volume and intensity, their associations with ECG characteristics in amateur university athletes are of practical interest. The present study examined associations of total and intensity-specific IPAQ-derived physical activity with ECG characteristics in amateur university athletes over the preceding seven days. Materials and Methods. This cross-sectional study examined 149 amateur student-athletes (70 males, 79 females; mean age 20.04 ± 1.47 years) at Hassan 1st University, Morocco. Physical activity was quantified in MET-min/week via the IPAQ-SF, and 12-lead ECGs were interpreted according to the 2017 International Criteria. Participants were stratified into MET-min/week tertiles (T1 ≤ 2,616, n = 50; T2 2,617–4,692, n = 50; T3 > 4,692, n = 49). ECG parameters were compared across tertiles by ANOVA with Tukey's post-hoc correction and trend tests; Pearson correlations quantified activity–ECG associations. Results. No continuous ECG parameter differed significantly across tertiles (ANOVA, all p ≥ .077; Jonckheere–Terpstra, all p ≥ .27). Among categorical findings, only LVH voltage-criteria positivity showed a significant trend (2.0%, 10.0%, 14.3% across T1–T3; Cochran–Armitage p = .030); no other finding was significant (all p ≥ .19). A segmented-regression test for a non-linear threshold in Sokolow-Lyon V5 was not significant (F = 1.49, p = .22), with a wide bootstrap breakpoint 95% CI (1,348–6,207 MET-min/week). VPA showed nominally significant unadjusted correlations with QRS duration (r = .164, p = .045), Sokolow-Lyon V5 (r = .170, p = .038), and Cornell index (r = .184, p = .025), but none survived FDR correction (all q ≥ .29) or adjustment for sex (all p ≥ .42). VPA was a significantly stronger correlate than total volume only for QRS duration (Steiger's Z, p = .008), not for Sokolow-Lyon V5 (p = .32) or Cornell index (p = .067). Conclusions. ECG characteristics classified by the 2017 International Criteria showed little robust association with self-reported physical activity in this exploratory cross-sectional sample once multiplicity and sex confounding were accounted for. The significant trend in LVH voltage criteria and the absence of a supported activity threshold indicate that these results are hypothesis-generating. The present study does not evaluate diagnostic performance; dedicated validation is required before any screening application.

Background. Managing training load and recovery in developing elite footballers is a major challenge for optimizing performance while limiting the risk of neuromuscular fatigue. Vertical jump with countermovement (VJM) remains a preferred indicator of neuromuscular status, but recovery kinetics after microcycles of contrasting intensity remain insufficiently documented in young athletes. Objectives. To examine the impact of training load and recovery time on neuromuscular performance by analyzing the modulating effects of microcycle type, age category, and acute-to-chronic workload ratio (ACWR). Materials and Methods. Seventy-five elite male footballers (U16-U18) participated in a six-month longitudinal protocol including CMJ assessments before and 24 h and 48 h after moderate- and high-intensity microcycles. Linear mixed models were used to analyze main effects and interactions. Results. Significant effects were observed for microcycle type (F = 69.93, p < 0.001), measurement time (F = 374.48, p < 0.001), and ACWR (F = 7.41, p = 0.007). High-intensity microcycles induced greater decreases in CMJ performance at 24 h (β = -1.072, p < 0.001), followed by partial recovery at 48 h. ACWR was strongly correlated with CMJ changes at 24 h (r = -0.766, p < 0.001). Conclusion. A critical window of neuromuscular fatigue exists 24 h after a microcycle, modulated by training intensity and workload context, supporting the value of systematic neuromuscular monitoring following high-intensity microcycles.