Protective effects of low-intensity exercise on metabolic oxidative capacity and capillarization in skeletal muscle of non-obese diabetic rats.

Diabetes mellitus induces skeletal muscle dysfunction, such as decreased metabolic activity and capillarization. This study aimed to investigate the effects of aerobic low intensity exercise training on metabolic oxidative capacity and capillarization in skeletal muscle of non-obese diabetic rats. Eleven to twenty-five week-old male non-obese Spontaneous Diabetic Torii (SDT) rats (n = 11) and age-matched healthy male Sprague-Dawley SD rats (n = 11) were randomly assigned to either exercise or sedentary groups. The exercise training was performed on a low-speed motorized treadmill (15 m min-1) for 60 min per session, 5 sessions per week for 14 weeks in exercised groups. Sedentary SDT rats resulted in hyperglycemia, reduction of metabolic oxidative enzyme, and low percentage of oxidative fibers in the skeletal muscles. The low-intensity exercise training inhibited the growth-related increase in glucose level, and increased the muscle oxidative enzyme in exercised SDT rats compared with sedentary SDT rats. In addition, the exercise program prevented capillary regression in the skeletal muscle of diabetic rats. These results suggest that low-intensity exercise training may be an effective treatment to counter the detrimental effects of type 2 diabetes mellitus on the oxidative capacity and the capillary network of skeletal muscles.