<p>BACKGROUND: The aim of this study was to determine and compare the effects of moderate and high intensity aerobic exercise on body composition, aerobic capacity, and metabolic factors in obese participants.METHODS: Twenty-five participants with obesity were randomized to high intensity interval training (HIIT) (N.=13) or moderate intensity continuous training (MICT) (N.=12). They completed supervised training for 10 weeks. Maximal oxygen uptake was measured using a breath-by-breath system, body composition was measured using a body analyzer and abdominal subcutaneous fat thickness (ASFT) was measured using ultrasonography. Fasting blood glucose, insulin, glycohemoglobin, lipid profile, high sensitivity C-reactive protein, myostatin and neuregulin-4 were studied from blood samples. All parameters were evaluated before and after the exercise program.RESULTS: Waist and hip circumferences decreased in both training groups (P&lt;0.05). Body Mass Index reduced with MICT (P&lt;0.05) and ASFT decreased with HIIT (P&lt;0.05). HIIT exhibited a significant increase in HDL cholesterol than MICT (P&lt;0.05). Both MICT (P&lt;0.001) and HIIT (P&lt;0.05) showed significant improvement in maximal oxygen uptake. Plasma neuregulin-4 and myostatin levels did not change in both training groups.CONCLUSIONS: This study demonstrated that both MICT and HIIT lead to cardiovascular and metabolic benefits. It is important to examine the effects of different intensity exercises on adipokines and myokines such as neuregulin-4 and myostatin, as it may be a new treatment target in obesity<br></p>