Continuous vs interval training on glycemic control and macro- and microvascular reactivity in type 2 diabetic...

To determine the effects of continuous aerobic exercise training (CON) vs interval aerobic exercise training (INT) on glycemic control and endothelium-dependent vasodilatation, 43 participants with type 2 diabetes were randomly allocated to the sedentary, CON, and INT groups. The CON and INT exercise training programs were designed to yield the same energy expenditure/exercise session and included walking on treadmill for 30 and 40 min/day, 3 times/week for 12 weeks. Body fatness and heart rate at rest decreased and leg muscle strength increased (all P < 0.05) in both the CON and INT groups. Fasting blood glucose levels decreased (P < 0.05) in both exercise groups but glycosylated hemoglobin levels decreased (P < 0.05) only in the INT group. Maximal aerobic capacity, flow-mediated dilation, and cutaneous reactive hyperemia increased significantly in both exercise groups; however, the magnitude of improvements was greater in the INT group. Only the INT group experienced reductions in erythrocyte malondialdehyde and serum von Willebrand factor and increases in plasma glutathione peroxidase and nitric oxide (all P < 0.05). We concluded that both continuous and interval training were effective in improving glycemic control, aerobic fitness, and endothelium-dependent vasodilation, but the interval training program appears to confer greater improvements than the continuous training program.