Low-intensity exercise reduces the prevalence of hyperglycemia in type 2 diabetes

Abstract

Introduction: Glycemic instability is a severely underestimated problem in type 2 diabetes treatment. Therapeutic targets should aim to reduce postprandial blood glucose excursions. Exercise prescription can effectively improve glucose homeostasis and reduce the risk of cardiovascular complications. Aim: To assess the impact of a single, isoenergetic bout of low-(LI) and high-intensity (HI) exercise on the prevalence of hyperglycemia throughout the subsequent 24-h postexercise period in longstanding type 2 diabetes patients. Methods: Nine sedentary, male type 2 diabetes patients (age = 57 ± 2 yr, body mass index = 29.0 ± 1.0 kg•m, Wmax = 2.2 ± 0.2 W•kg body weight) were selected to participate in a randomized crossover study. Subjects performed an isoenergetic bout of endurance-type exercise for 60 min at 35% Wmax (LI) or 30 min at 70% Wmax (HI) or no exercise at all (NE). Thereafter, glycemic control was assessed during the subsequent 24-h postexercise period by contnuous glucose monitoring under strict dietary standardization but otherwise free-living conditions. Results: Average 24-h glucose concentrations were reduced after the LI exercise bout (7.8 ± 0.9 mmol•L) when compared with the control experiment (9.4 ± 0.8 mmol•L; P < 0.05). The HI exercise bout did not significantly lower mean glucose concentrations (8.7 ± 0.7 mmol•L; P = 0.14). Hyperglycemia was prevalent for as much as 35% ± 9% throughout the day (NE). A single bout of exercise reduced the prevalence of hyperglycemia by 50% ± 4% (P < 0.05) and 19% ± 9% (P = 0.13) in the LI and HI exercise experiments, respectively. Conclusions: A single bout of LI, as opposed to HI, exercise substantially reduces the prevalence of hyperglycemia throughout the subsequent 24-h postexercise period in longstanding type 2 diabetes patients. Copyright © 2010 by the American College of Sports Medicine.