Sport-Specific Neuromuscular Profiles in Male Youth Swimmers and Sailors: A Comparative Analysis

Understanding the distinct biomechanical and neuromuscular demands of aquatic sports is key to developing targeted training strategies for youth athletes. This study compared neuromuscular profiles between male youth Thai swimmers and Optimist sailors by examining the Dynamic Strength Index (DSI) in upper and lower limbs. A secondary aim was to assess the relationships between the biological maturity, estimated via 2D:4D digit ratios and predicted peak height velocity (PHV) and neuromuscular performance. Forty male athletes (n = 20 per group; mean age: swimmers = 12.9 ± 0.7, sailors = 13.3 ± 0.8 years) completed ballistic (Countermovement Jump, push-up) and isometric (Isometric Mid-Thigh Pull, grip strength) tests. Swimmers showed significantly greater neuromuscular output in both limbs, with higher CMJ peak force (mean diff: 339.78 N; p < 0.001, d = 1.64) and push-up force (mean diff: 135.26 N; p < 0.001, d = 1.51), resulting in higher lower-limb DSI (0.86 vs. 0.70; p < 0.01, d = 0.89). Two-way ANOVA revealed a significant limb effect (p < 0.001, η² _p = 0.631) and a sport × limb interaction (p = 0.002, η² _p = 0.104), indicating sport-specific neuromuscular adaptations. Correlational analysis showed positive associations between lower-limb DSI and right-hand digit lengths and a negative relationship with PHV. These results underscore the importance of tailoring strength training to the sport-specific and maturational profiles of male youth athletes.