Abstract

To study the effect of two individual training intensities on total fat, waist circumference (WC), lipid parameters, and insulin-resistance among obese women were used. Thirty one obese women underwent 12 weeks of aerobic training. The training intensity was established according to the maximal heart-rate reserve (HRR). They were randomly assigned to one of three groups: a moderate intensity training group (G50, exercising at 50% of the HRR, n=11), a high intensity training group (G75, exercising at 75% of HRR, n=10), and a control group (GC, completed all tests but did not train, n=10). Anthropometric and biochemical measurements were performed before and after the training periods. G75 and G50 showed a significant decrease in body-mass-index (-7.1 versus -3.3%, P<0.001 and P<0.01, respectively), total fat (-14.4 versus -9.5%, P<0.001), and in WC (-9.4 versus -8.1%, P<0.001 and P<0.01, respectively). The reduction of total fat and WC were significantly correlated with body mass decrease (r=0.46 and r=0.43, respectively, P<0.001) among the two training groups but the change in body composition was not correlated with lipid parameters. In addition, the decrease of the homeostasis model assessment index was higher (P<0.001) in G50 than G75 with a significant reduction in LDLc. The training program at 50% of HRR induced a significant reduction of LDLc and a significant improvement in insulin status associated with body mass reduction, total fat, and WC. However, the training program at 75% of HRR induced more significant reduction in body mass and total fat than that at 50% of HRR.

Key words: Obese women, lipids, insulin resistance, anthropometric parameters, exercise intensity.