Wearing an insulin pump during exercise is not necessary, according to a study reported in Pediatrics (September 2005). Researchers found that patients aged 10 to 19 years with type 1 diabetes using the pump may face an increased risk of low blood sugar (hypoglycemia) after exercising.
For the study, 10 patients exercised with the insulin pump on and off. They exercised for 40 to 45 minutes on a bicycle for 2 hours after a standard breakfast and an insulin bolus. The group consumed 20 g of carbohydrates before and after exercising. Overall, the researchers found that this type of exercise "is equally performed, perceived, and safe [in terms of acute hypoglycemia]" with the pump on or off. The results showed, however, that late (after exercise) hypoglycemia was more frequent, compared with acute (during exercise) hypoglycemia. There was a tendency toward greater risk of late hypoglycemia with the pump on during exercise.