[Strength training improves insulin sensitivity and plasma lipid levels without altering body composition in overweight and obese subjects]

Abstract

Objective: To assess the effect of long-term strength training on insulin sensitivity, lipid profile, and body composition in overweight and obese subjects.

Materials and methods: A prospective, randomized, interventional study in 16 overweight or obese subjects aged 18-35years who were investigated before and at the end of 8weeks of strength training. The experimental group (n=8) followed a strength training program consisting of 4 sessions per week at 50% to 80% of repetition maximum (RM), estimated through the 1RM test. The control group (n=8) did not perform the training program. Glucose, insulin, total cholesterol, triglycerides, HDL-C, VLDL-C, and LDL-C levels and arterial index were determined. Insulin sensitivity was measured by calculating HOMA-IR (Homeostatic Model Assessment-Insulin Resistance). Indicators of body composition included weight, height, waist circumference, body fat, fat weight, muscle mass, somatotype chart and distance.

Results: At the end of intervention, the experimental group showed a decrease of insulin sensitivity (3.5±0.9 vs. 2.9±1.2; p=0.04), LDL-C (106.9±20.8 vs. 95.5±14.2; p=0.03), and arterial index (4.0±0.6 vs. 3.5±0.5; p=0.01), as well as an increase in HDL-C levels (43.7±8.8 vs. 46.9±5.6; p=0.04), while the control group remained stable. There were no significant differences between groups in body composition, somatotype chart and distance after training.

Conclusions: In overweight and obese subjects, strength training for eight weeks improved insulin sensitivity and lipid profile without altering body composition.