Exploratory Associations Among Lower-Limb Strength, Selected Isokinetic Knee-Extension Variables, Countermovement Jump Flight Time, and Short-Duration Anaerobic Power in Healthy Male University Students

Background: Lower-limb performance is commonly assessed using maximal strength, isokinetic, jump, and anaerobic power tests, but whether these assessments provide overlapping or complementary information in healthy young adults without recent regular resistance training remains unclear. Methods: This exploratory cross-sectional secondary analysis examined associations among lower-limb maximal strength, selected isokinetic knee-extension variables, countermovement jump (CMJ) flight time, and 6 s Wingate peak power in 30 healthy male university students. Maximal dynamic strength was assessed using one-repetition maximum (1RM) tests for leg press, leg extension, and leg curl. Isokinetic knee function was evaluated using 60°/s knee extension peak torque and 180°/s knee extension total work. Pearson correlations, body-mass-adjusted partial correlations, and exploratory regression models were performed. Results: Leg press 1RM was strongly correlated with 6 s Wingate peak power, but not with CMJ flight time, in the zero-order analysis. After body-mass adjustment, leg press 1RM was associated with both outcomes. In exploratory regression models, leg press 1RM showed the most consistent associations, whereas the selected isokinetic variables showed less consistent relationships. Conclusions: In this exploratory sample, leg press 1RM showed the most consistent associations with the two performance outcomes examined, particularly 6 s Wingate peak power. The selected isokinetic knee-extension variables appeared to provide more joint-specific information. These findings should be interpreted as sample-specific associations, not as evidence that one test can predict or replace another.