Effect of Moderate-Intensity Exercise Versus Activities of Daily Living on 24-Hour Blood Glucose Homeostasis in Male Patients With Type 2 Diabetes

OBJECTIVE To investigate the impact of activities of daily living (ADL) versus moderate-intensity endurance-type exercise on 24-h glycemic control in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS Twenty males with type 2 diabetes participated in a randomized crossover study consisting of three experimental periods of 3 days each. Subjects were studied under sedentary control conditions, and under conditions in which prolonged sedentary time was reduced either by three 15-min bouts of ADL (postmeal strolling, ∼3 METs) or by a single 45-min bout of moderate-intensity endurance-type exercise (∼6 METs). Blood glucose concentrations were assessed by continuous glucose monitoring, and plasma insulin concentrations were determined in frequently sampled venous blood samples. RESULTS Hyperglycemia (glucose >10 mmol/L) was experienced for 6 h 51 min ±1 h 4 min per day during the sedentary control condition and was significantly reduced by exercise (4 h 47 min ± 1 h 2 min; P < 0.001), but not by ADL (6 h 2 min ± 1 h 16 min; P = 0.67). The cumulative glucose incremental areas under the curve (AUCs) of breakfast, lunch, and dinner were, respectively, 35 ± 5% (P < 0.001) and 17 ± 6% (P < 0.05) lower during the exercise and ADL conditions compared with the sedentary condition. The insulin incremental AUCs were, respectively, 33 ± 4% (P < 0.001) and 17 ± 5% (P < 0.05) lower during the exercise and ADL conditions compared with the sedentary condition. CONCLUSIONS When matched for total duration, moderate-intensity endurance-type exercise represents a more effective strategy to improve daily blood glucose homeostasis than repeated bouts of ADL. Nevertheless, the introduction of repeated bouts of ADL during prolonged sedentary behavior forms a valuable strategy to improve postprandial glucose handling in patients with type 2 diabetes.