Association between aerobic capacity and the improvement in glycemic control after the exercise training in type 2 diabetes

BACKGROUND: We investigated the influence of aerobic capacity on the improvement in glycemic control achieved by long-term aerobic exercise in type 2 diabetes. METHODS: Fifty-three male patients with type 2 diabetes, recruited from outpatient clinics, wore multiple-memory accelerometers and were instructed to exercise at moderate intensity for ≥30 min on ≥3 days per week over 12 months. Peak oxygen uptake (peak [Formula: see text] ) and serum glycated albumin (GA) were measured at baseline and after 3, 6, 12 months. Peak [Formula: see text] data were expressed as percentages of predicted values. RESULTS: According to the number of bouts of exercise (intensity, ≥4 METs; duration, ≥15 min), the subjects were divided into inactive (<3 times per week) or active (≥3 times per week) groups. Serum GA decreased significantly after 3, 6, 12 months only in the active group. When the subjects were assigned to four groups according to initial peak [Formula: see text] (%pred) (low-fitness or high-fitness) and the number of bouts of exercise (active or inactive), serum GA decreased significantly after 3, 6, 12 months only in the high-fitness/active group. When the subjects were also assigned to four groups according to the change in peak [Formula: see text] (%pred) (improved or unimproved) and the number of bouts of exercise (active or inactive), serum GA decreased significantly after 3 and 12 months only in the improved/active group. CONCLUSION: The improvement in glycemic control achieved by aerobic exercise was associated with both the initial and the increase in peak [Formula: see text] during aerobic exercise. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13098-017-0262-9) contains supplementary material, which is available to authorized users.