Multivariable associations of lower-limb performance indicators with sprint and reactive agility in elite female handball players

Acceleration, short-distance sprinting, and rapid change-of-direction are critical performance determinants in handball. This study examined the associations between key lower-limb performance indicators and sprint/reactive agility outcomes and evaluated their independent associations within multivariable models in elite female handball players. Twenty-seven athletes (n = 27; age 15.61 ± 0.69 years) completed assessments of countermovement jump (CMJ), squat jump (SJ), reactive strength index (RSI_{3–5}), leg stiffness, and relative power; sprint performance (0–5–10–20 m) and reactive agility were evaluated using standardized field protocols. Pairwise relationships were analysed using Pearson’s correlations, and independent contributions were evaluated with AIC-guided multivariable linear regression (standardized β, adjusted R²). Strong associations were observed between CMJ/RSI and sprint/agility parameters (r = 0.65–0.89, p < 0.01). In regression models, RSI and leg stiffness were retained as significant associated variables, particularly in relation to the 5–20 m sprint segments and reactive agility (standardized β = 0.31–0.67). The models showed high explanatory capacity for sprint outcomes, reaching an adjusted R² of 0.825 in the 5–10 m sprint model, and more moderate explanatory capacity for agility outcomes (adj. R² = 0.422). These findings indicate that jump-derived elastic/neuromuscular indices, particularly RSI and leg stiffness, are independently associated with sprint and reactive agility performance in elite female handball players. However, given the cross-sectional design, these associations should not be interpreted causally. The results may help identify candidate performance-monitoring variables for practice settings. Prospective and intervention-based studies are required to determine whether modifying these variables improves sprint or agility outcomes.