Effect of diet therapy on maximum aerobic power in obese, hyperglycaemic men with recently diagnosed type 2 diabetes

To find out the effect of correction of hyperglycaemia on maximum aerobic power and anaerobic threshold, we studied 40 middle-aged obese men with recently diagnosed type 2 diabetes before and after 3 months diet therapy. Respiratory gas exchange was measured during maximal incremental bicycle exercise test with breath-by-breath technique at rest, at anaerobic threshold and at peak exercise. As a whole group, the diabetic men reached higher work load after therapy (+9 +/- 3 W (mean +/- SEM), p less than 0.01). A weak inverse linear correlation was found between the changes in fasting blood glucose and in maximum oxygen uptake (r = -0.29, p less than 0.05). When the patients were divided into two groups according to the median values in the change in fasting blood glucose, only those men with more than 1 mmol l-1 decrease in fasting blood glucose improved maximum oxygen uptake (+124 +/- 55 ml min-1 or +6%, p less than 0.05). Oxygen uptake at anaerobic threshold did not change significantly. These results suggest that the correction of hyperglycaemia by diet therapy may improve maximal aerobic power in obese men with recently diagnosed type 2 diabetes.