Although ideally dose adjustments should be made at least 30 minutes before starting exercise, pump therapy does allow for impromptu activity, which can be beneficial especially in younger people. Young people with diabetes who suspend basal insulin during exercise suffer significantly less hypoglycaemia when compared with those who continue their usual basal rate during exercise , but it should be noted that this results in a significant increase in post-exercise hyperglycaemia. This is important, as it increases the risk of deterioration in overall glycaemic control, and more importantly the risk of ketosis. An alternative strategy is to continue basal insulin during exercise , with the rate reduced depending on the intensity and duration of the exercise, and this seems now to be the preferred option. However there are as yet no studies to advise what would be an appropriate basal dose reduction (or even increase) for various type and duration of exercise, and how long before and after exercise that these changes should best be made.
Following intense exercise, hyperglycaemia may be problematic. This can be managed with a corrective bolus dose of insulin, and may be anticipated with experience.