Impact of time interval from the last meal on glucose response to exercise in subjects with type 2 diabetes

We evaluate the influence of the time interval from the last meal on the blood glucose response to exercise in men with type 2 diabetes. Nineteen men with type 2 diabetes participated in an exercise training program carried out at 60% of maximal oxygen uptake (VO2peak) for 1 h, 3 times a week. Capillary whole blood glucose was measured immediately before and after each exercise session, and the time interval from the last meal (breakfast, lunch, or dinner) was recorded. Seven time intervals were considered (fasted overnight and 0-1, 1-2, 2-3, 3-4, 4-5, and 5-8 h postmeal). A total of 1,045 exercise sessions were analyzed. There was no change in blood glucose levels when individuals were in the fasted state (mean +/- SE, 8.1 +/- 0.2 vs. 8.1 +/- 0.1 mmol/L; before vs. after, respectively). However, blood glucose decreased by 28 +/- 1% at 0-1 h, by 33 +/- 1% at 1-2 h, by 35 +/- 1% at 2-3 h, by 38 +/- 2% at 3-4 h, by 43 +/- 2% at 4-5 h, and by 23 +/- 3% at 5-8 h (all P < 0.001). These results demonstrate that 1 h of ergocycle exercise has no clinical impact on blood glucose when performed in the fasted state in men with type 2 diabetes, whereas a significant decrease in blood glucose should be expected when the same exercise is performed postprandially.