Objective: The study aimed to investigate the effects of 8-week aquatic high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on body composition, aerobic fitness and vascular function in overweight/obese adults.
Methods: Forty-one overweight/obese adults were randomly assigned to HIIT or MICT group. HIIT group performed twelve 30-s swimming exercise bouts with the intensity of 90%-95% HRmax with a 60-s rest period between each bout. MICT group performed a 30-min uninterrupted swimming exercise with the intensity of 70%-75% HRmax. Training frequency for both groups was three times a week for 8 weeks. Before and after exercise intervention, Inbody 370 was used to test the body composition of the subjects. Carotid femoral pulse wave conduction velocity (cfPWV) and brachial-ankle pulse wave conduction velocity (baPWV) were used as indicators to evaluate the the central and peripheral artery stiffness, respectively. Brachial artery flow-mediated vasodilation response (FMD) was measured using the non-invasive ultrasound UNEXEF38G system. Maximal oxygen uptake was measured using the power bicycle experiment MasterScreen CPX.
Results: Both HIIT and MICT could effectively reduce body weight and BMI. However, HIIT group rather than MICT group showed a significant increase in skeletal muscle and significant decrease in chest circumference and waist circumference after 8 weeks of intervention. Moreover, both HIIT and MICT could effectively increase aerobic fitness and endothelial function. Whereas, no changes in the central and peripheral artery stiffness were seen in neither HIIT group nor MICT group.
Conclusion: Both HIIT and MICT swimming interventions at 8 weeks significantly improved body composition and vascular endothelial function in overweight/obese adults, but had no significant effect on central and peripheral arterial stiffness.