Effect of exercise intensity on body composition and cardiovascular disease risk factors in sedentary young obese women : original research

Background : The optimal exercise prescription to maximize fat abdominal loss and prevent insulin-resistant and metabolic disorders remains elusive. Research question : To examine the effect of exercise intensity on cardiovascular disease risk factors in correlation with cardiorespiratory improvements in young obese women. Type of study : Longitudinal study. Method : 43 young obese women were randomly assigned to one of four groups: a moderate-intensity-training group (G1, exercising at 50% of the heart rate reserve (HRR)), a high-intensity-training group (G2, exercising at 75% of HRR), an alternate-intensity-training group (G3, exercising at 50-75% of HRR), and a control-group (G0). Waist circumference (WC), lipoproteins, fasting glucose, insulin, resting HR (RHR) and the 6-min-walk distance (6MWD) performance were recorded before and after 12 weeks of a walking-training program. Results : Body mass, BMI, total fat, and WC decreased significantly from T0 to T1 (p<0.001) in the three training groups with higher decrease in G2 than in G1 and G3. For lipids, although total cholesterol diminished in G3 (p<0.001), there was no significant difference between the three training intensities. The insulin and Homa-IR decreased in the three training groups (p<0.001). Conclusion : The loss of BMI, weight, body fat mass, and WC was greater after high-intensity training. However, alternate-intensity training induced a reduction in total cholesterol and an improvement in insulin sensitivity. Therefore, the alternate-intensity training would provide the greatest training benefit in managing coronary heart disease risk factors.