Studies on the mechanism of improved glucose control during regular exercise in Type 2 (non-insulin-dependent) diabetes

The effects of 6 weeks of thrice weekly training on glycaemic control were assessed in 20 sedentary Type 2 (non-insulin-dependent) diabetic patients and 11 control subjects matched for previous physical activity. Maximal oxygen uptake was lower in the diabetic patients than in control subjects before training (26.2±1.1 versus 32.6±1.7 ml·kg^-1·min^-1; p<0.001). Glycosylated haemoglobin levels decreased in the diabetic patients during the training programme (12.2±0.5 to 10.7±0.4%; p < 0.02). Oral and intravenous glucose tolerance determined 72 h after the last exercise period showed only minimal improvement. Plasma glucose levels were, however, significantly lower at 12 h than 72 h after exercise in eight subjects tested at both time points. These data suggest that an exercise programme can produce a significant decrease in glycosylated haemoglobin levels in Type 2 diabetic males probably due, in great measure, to the cumulative effect of transient improvements in glucose tolerance which follow each individual period of exercise.