Effects of a controlled program of moderate physical exercise on insulin sensitivity in nonobese, nondiabetic...

To study the effect of a moderate, aerobic physical exercise program on insulin resistance and its accompanying metabolic changes in a group of healthy, middle-age, nonobese subjects, without modifying oxygen consumption and body weight.

The inclusion of subjects was carried out among volunteers from the health personnel of our center, who complied with the inclusion criteria.

Twelve subjects (age 30-60 years, 5 females), nonsmokers, body mass index (BMI) <27 kg/m2 and fasting plasma glucose <6.1 mmol/L.

Insulin resistance was assessed using the Bergmann minimal model modified with insulin, and basal and maximum metabolic rate were measured with standard methods. All subjects completed a 2-month program of aerobic exercise using the American College of Sports Medicine guidelines, consisting of aerobic exercise of moderate, regular, and continual intensity (3 times per week), with a duration of 45 to 50 minutes per session.

Following controlled exercise, no significant differences in BMI, waist-hip ratio, blood pressure, lipids, free fatty acids, and leptin plasma values were observed. Plasma glucose and insulin values decreased significantly (-0.37 mmol/L and -16.5 pmol/L, respectively). Insulin sensitivity showed an increase of 2.1 x 10(-4) mU L(-1) min(-1) (P = 0.001). Basal and maximum metabolic rate showed no significant differences after the exercise program.

Moderate aerobic exercise increases insulin sensitivity in nonobese, nondiabetic subjects in the absence of significant changes in weight, BMI, waist-hip ratio, lipid profile, and oxygen consumption.