The Impact of Sport-Specific Practice on Health-Related Physical Fitness Components in Young Water Polo and Volleyball Athletes

Physical fitness (PF) has been identified as a critical health marker in youth and is significantly influenced by environmental factors, such as the specificity of training involved in different sports. This study investigated PF differences among young athletes who participated in water polo and volleyball to understand how different training programs and environments impact physical development. A sample of 98 youth athletes, including 46 water polo players (46% female; mean age: 13.07 ± 2.27 years) and 52 volleyball players (100% female; mean age: 13.80 ± 1.86 years) was assessed using Handgrip (HG), Standing Long Jump (SLJ), and Progressive Aerobic Cardiovascular Endurance Run (PACER) tests. Results were normalized against European percentile reference values and analyzed using the Mann–Whitney U test. The PACER test revealed a significant difference (U = 639, p < 0.001, r = −0.466), with water polo athletes exhibiting superior cardiorespiratory fitness compared to volleyball players. The HG test also showed significant differences (U = 1571, p = 0.007, r = 0.314), indicating greater grip strength in volleyball players. No significant difference was observed in the SLJ test. These findings underscore the importance of sport-specific training in youth athletes, but also the importance of well-rounded physical development training for all youth sports. Results suggest that practicing different sports that involve different training and environments is significantly associated with certain aspects of PF components. This awareness can guide grassroots coaches and trainers towards effective and balanced training strategies to promote performance and long-term health.