The role of physical exercise and training in the management of diabetes mellitus.

The effects of physical activity on blood glucose homeostasis in diabetes mellitus and the potential benefits of exercise in the treatment of diabetic patients, are reviewed. Mild physical exercise results in a fall of blood glucose levels in controlled diabetic patients; this acute effect of exercise might be used in particular to inhibit the rise of blood glucose seen in insulin-treated diabetics after food intake. In contrast, physical activity will further deteriorate the metabolic situation in decompensated diabetic patients by an increase in blood glucose and a rapid aggravation of ketosis. On the other hand exercise potentiates the blood glucose lowering effect of subcutaneously injected insulin; therefore precautions have to be taken in order to avoid hypoglycemia in insulin-dependent diabetics especially during and after more strenous exercise. In juvenile-type diabetes, physical activity can be used as an efficient therapeutic adjunct only in cooperative, well-instructed patients who are used to check their metabolic situation on a regular basis. Physical training increases the tissues' sensitivity towards (endogenous) insulin. Hence, in addition to the diet, training might represent the most appropriate treatment in maturity onset-type diabetic patients. However, direct evidence for an improvement of glucose tolerance in diabetic patients by physical training is still lacking. In order to formulate detailed, generally applicable recommendations on how to carry out a useful therapeutic program of physical exercise and/or training in diabetic patients, further clinical studies assessing the quantitative effects of physical activity on carbohydrate metabolism are needed.