Cardiorespiratory Fitness Assessed by Direct VO₂peak Measurement in Adolescent and Young Adult Males With...

Introduction Individuals with developmental disorders (DD) often exhibit reduced levels of daily physical activity, contributing to diminished cardiorespiratory fitness. While field-based tests such as the 20-meter shuttle run and six-minute walk test are commonly used for indirect assessment, few studies have employed direct measurement of peak oxygen uptake (VO₂peak), the gold standard for evaluating aerobic capacity. This study aimed to evaluate VO₂peak using a maximal exercise test in adolescent and young adult males with developmental disorders. Methods A cross-sectional study was conducted with 41 male participants aged 15-20 years with diagnosed developmental disorders. After excluding individuals with BMI >30, 37 participants completed a ramp protocol maximal exercise test on a cycle ergometer. VO₂peak was measured using breath-by-breath gas analysis. Values were compared to established normative data for healthy Japanese males of similar age. Results The mean absolute VO₂peak was 2209.9 ± 458 mL/min, and the weight-adjusted VO₂peak was 38.1 ± 6.8 mL/min/kg. Only 6 out of 37 participants fell within the normative range (95% CI: 44.2-60.2 mL/min/kg), indicating significantly reduced cardiorespiratory fitness in this population. This study is among the first to report directly measured VO₂peak using a ramp protocol in individuals with developmental disorders. Conclusion Adolescent and young adult males with developmental disorders demonstrated substantially lower VO₂peak values compared to their typically developing peers. These findings highlight the need for targeted physical activity interventions and provide reference data for future research in this under-investigated population.