Lower-Body Strength Strongly Predicts Punch Impact Force in Professional Kickboxers

Lower-body strength is theoretically central to punch performance, but the strength of this relationship in trained kickboxers is poorly quantified. This study examined whether countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) peak force predict rear-arm punch impact force in professional kickboxers. Fourteen athletes (age: 24 ± 4 years; body mass: 70.7 ± 8.6 kg) from K-1 Japan weight categories with a minimum of three years of competitive experience completed lower-body force testing and a standardized punch impact protocol. CMJ peak force (r = 0.71, p = 0.005) and IMTP peak force (r = 0.57, p = 0.034) demonstrated moderate-to-strong correlations with punch impact force. Multiple regression analysis revealed that these measures collectively accounted for 60% of the variance in punch impact force (R² = 0.598). These findings demonstrate that maximal lower-body force production capacity represents a primary determinant of punch impact force in professional kickboxers.