PURPOSE This study aimed to develop and validate sex-specific maximal oxygen uptake (VO2max) prediction equations for Korean elite athletes aged 10–20 years using physiological and fitness variables derived from the standardized KISS treadmill protocol. METHODS This study used data from 526 elite athletes (373 boys, 153 girls), including adolescents and adults in the Gyeongnam region. VO2max was measured over 2 years using the KISS protocol. Multiple regression analyses were conducted with measured VO2max as the dependent variable and age, height, body weight, body fat percentage, total exercise time, maximal heart rate (HRmax), and reasons for test termination as independent variables. RESULTS The regression equation for male athletes was: VO2max = 45.233 + (0.024 × total time) − (0.097 × body weight) − (1.260 × reason for termination) − (0.112 × body fat percentage). The regression equation for female athletes was: VO2max = 22.913 + (0.024 × total time) − (0.220 × body weight) + (0.106 × HRmax). When compared with five existing prediction models, the proposed equations demonstrated the highest correlation coefficients (male r = 0.743; female r = 0.749). The standard error of estimate for the developed models was 4.27 and 3.57 mL·kg−1·min−1 for males and females, respectively. CONCLUSIONS The sex-specific VO2max prediction equations developed in this study can serve as reliable alternative tools for evaluating cardiorespiratory endurance in elite athletes. Further research incorporating a broader range of physiological variables and age groups is warranted to validate and refine these models.
