Effects of aerobic and resistance exercise training on insulin action in the elderly

Abstract

Background: Aging is associated with a declining glucose tolerance, which is primarily caused by peripheral insulin resistance, and with a decline in physical activity. The aim of this study was to assess the effect of aerobic and resistance exercise training on insulin action in the elderly. Methods: Fourteen healthy male subjects (age: 65–73 years) were enrolled and divided into two exercise groups: resistance training (RT) or a combined aerobic and resistance training (CT). Subjects participated in each training program three times a week for 12 weeks. Before and after the training program, insulin action was determined using the euglycemic clamp technique at insulin infusion rates of 40 (low) or 400 (high) mU/m 2 per min. Body composition was measured by dual‐energy X‐ray absorptiometry (DXA). Results: Percent fat decreased significantly in both groups. Fat‐free mass (FFM) tended to increase in the RT group ( P = 0.054), but not in the CT group. In the CT group, the glucose infusion rate (GIR) increased 16.6% ( P < 0.05) at the low insulin infusion rate and 21.7% ( P < 0.01) at the high rate. In the RT group, GIR tended to increase at the low insulin infusion rate, but was not statistically significant ( P = 0.052) and increased 9.9% ( P < 0.05) at the high rate. When calculated per FFM, the increased insulin action persisted in the CT group ( P < 0.01), but not in the RT group. Conclusion: The combination of aerobic and resistance training is more effective for improving the decreased insulin action in the elderly than resistance training alone.