Effects of Accumulated and Continuous High-Intensity Aerobic Exercise on Cardiorespiratory Fitness and Circulating ANGPTL6 Levels in Obese Adolescents

This study compared the effects of high-intensity aerobic exercise, implemented over eight weeks in two formats-accumulated exercise (AE) and continuous exercise (CE)-on body composition, cardiorespiratory fitness, metabolic health, liver function, and serum ANGPTL6 levels in obese adolescents.A total of 29 participants were randomly assigned to the AE(n = 10), CE(n = 10), or control (C) group(n = 9).Pre-and post-intervention assessments included body measurements, V ̇O2 peak evaluation, and blood biochemical analyses.The results showed significant reductions in body mass index (BMI) and body fat percentage (p < .05),with V ̇O2 peak significantly improved in the AE group compared to the control group (p < .05).Low-density lipoprotein cholesterol (LDL-C) was significantly reduced after the intervention (p < .05),and serum ANGPTL6 levels were significantly lower in the AE group than in the CE group (p < .05).Meanwhile, alanine aminotransferase (ALT) levels were significantly higher in the AE group than in the CE group (p < .05),suggesting differential hepatic responses depending on the exercise modality.These findings indicate that accumulated high-intensity aerobic exercise may be a more effective intervention strategy than continuous exercise for improving cardiorespiratory fitness and regulating hepatic metabolic stress in obese adolescents.