[Physical exercise and insulin use: challenges for people with diabetes mellitus]

Physical exercise has many health benefits, equally so for people with diabetes mellitus. The glycaemic responses to the various types of exercise differ and include an increased risk of late (nocturnal) hypoglycaemia, making physical exercise a challenge for some people with diabetes who are treated with insulin. Insulin treatment interferes with normal physiologic responses to exercise, which are necessary to maintain the blood glucose level within the normal range. During aerobic exercise, the blood glucose concentration usually drops, whereas anaerobic exercise generally causes a rise in glycaemia in people with diabetes using insulin. In people with insulin treated diabetes, a combination of frequent (continuous) blood glucose monitoring, adjustments in insulin dose and ingestion of carbohydrates ensures a safe management of glycaemia during and after physical activity.