Effects of exercise on insulin sensitivity in obese women submitted to a weight loss program: a clinical trial

The aim of this study was to evaluate the effects of exercise on insulin sensitivity, lipid metabolism and weight loss in women submitted to a weight reduction program. The study consisted in a clinical trial including 40 obese women (BMI 30.41 to 53.29 kg/m(2)), 20 in each group. Both groups received nutritional counseling and psychological support. The intervention group participated in supervised exercise three times per week for 20 weeks. For the anthropometric measurements, which were taken at three times, the linear mixed modeling procedure showed a reduction of 2 kg in body mass (p = 0.02) and 0.88 kg/m(2) in the Body Mass Index (p = 0.02) in intervention group compared with controls after 20 weeks of treatment. We did not detect significant differences between the two groups for body fat location (waist circumference and waist-to-hip ratio), serum lipoprotein profile, and insulin sensitivity evaluated by HOMA-IR. Serum levels of free fatty acids significantly increased in the intervention group compared with controls (difference between groups = 0,30 mmol/L; p = 0,002). The addition of physical exercise in a weight reduction program promoted greater weight loss, increased free fatty acids, but did not alter insulin sensitivity in obese women.