BIOMECHANICAL, PHYSIOLOGICAL AND ENVIRONMENTAL DETERMINANTS OF JUMPING AND SPIKING PERFORMANCE IN COMPETITIVE VOLLEYBALL PLAYERS

Volleyball performance relies on repeated explosive movements such as jumping and spiking, which are determined by the interaction of biomechanical efficiency, neuromuscular coordination, physiological fitness, and body composition; however, comprehensive investigations integrating these determinants remain limited.This study aimed to examine the biomechanical and physiological determinants of jumping and spiking performance in competitive volleyball players, with particular emphasis on the influence of body composition on force-time characteristics and mechanical efficiency.Twenty-four competitive volleyball players participated in a crosssectional design and were classified into lower and higher skinfold groups based on the median value of six skinfold measurements.Anthropometric assessments were conducted, while biomechanical performance was evaluated using force-platform analysis during countermovement and volleyball-specific spike jumps.Performance variables including jump height, peak force, and peak power, expressed in both absolute and relative terms, were analyzed using independent samples t-tests, effect size calculations, and Pearson correlation coefficients.Athletes in the lower skinfold group demonstrated significantly greater countermovement and spike jump heights, along with superior absolute and relative force and power production, compared with players presenting higher subcutaneous fat mass.The largest between-group differences were observed in relative mechanical variables, highlighting the importance of normalizing performance outputs to body mass.Additionally, subcutaneous fat thickness showed strong negative associations with all biomechanical performance indicators, particularly relative peak power.Considering athletic performance within a broader human ecology perspective, environmental factors such as indoor training conditions, air quality, and thermal comfort may further influence neuromuscular efficiency and fatigue resistance during highintensity volleyball activities.Overall, the findings indicate that lower subcutaneous fat mass is strongly associated with improved explosive performance and biomechanical efficiency in volleyball-specific movements.This study provides an integrated biomechanical and anthropometric framework linking body composition to force-platform derived performance variables and supports the systematic integration of body composition monitoring and biomechanical assessment in volleyball training and performance optimization.