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

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.

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.

Nine sedentary, male type 2 diabetes patients (age = 57 +/- 2 yr, body mass index = 29.0 +/- 1.0 kg x m(-2), Wmax = 2.2 +/- 0.2 W x kg(-1) 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 continuous glucose monitoring under strict dietary standardization but otherwise free-living conditions.

Average 24-h glucose concentrations were reduced after the LI exercise bout (7.8 +/- 0.9 mmol x L(-1)) when compared with the control experiment (9.4 +/- 0.8 mmol x L(-1); P < 0.05). The HI exercise bout did not significantly lower mean glucose concentrations (8.7 +/- 0.7 mmol x L(-1); 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.

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.