Comparison of high‐intensity interval training and moderate‐intensity continuous training on cardiopulmonary function, cardiac autonomic function and vascular function in adolescent boys with obesity: A randomized controlled trial

Abstract Adolescent obesity can impair cardiopulmonary function, vascular elasticity, endothelial function, and vago‐sympathetic balance. While moderate‐intensity continuous training (MICT) benefits cardiovascular health in obese adolescents, the effects of high‐intensity interval training (HIIT) are less understood. We hypothesize that HIIT may be more effective than MICT in improving VO 2 peak, vascular elasticity, endothelial function, and vago‐sympathetic balance in obese adolescent boys. Forty four participants were randomly assigned to the HIIT (10 × 1‐min at 85%–95% peak HR, intersperse with 2‐min active recovery at 60%–70% peak HR) or MICT (35 min at 65%–75% peak HR) for an 8‐week program. The primary outcome measured was the change in VO 2peak with secondary outcomes including brachial‐ankle pulse wave velocity (baPWV), flow‐mediated dilation (FMD), and heart rate variability (HRV). Forty four adolescent boys with obesity (age, 14 ± 1 years old, body mass index, 31.6 ± 1.3 kg/m 2 ) were enrolled and 43 (97.73%) completed the 8‐week exercise. No significant difference of VO 2peak was found between the HIIT and MICT group ( p = 0.243). There was no significant difference of baPWV between the groups ( p = 0.789). Change in FMD% was significantly higher in the HIIT group compared to the MICT group ( p < 0.001). The Change in HRV‐high frequency (HRV‐HF; p = 0.009) and HRV‐low frequency/high frequency (HRV‐LF/HF; p = 0.035) was significantly higher in the HIIT group compared to the MICT group. Among adolescent boys with obesity, 8‐week HIIT and MICT had similar effects on improving VO 2peak . HIIT may be superior to MICT to improve endothelial function and vago‐sympathetic balance.