Glucose response to intense aerobic exercise in type 1 diabetes: maintenance of near euglycemia despite a drastic decrease in insulin dose.

In patients with type 1 diabetes, hypoglycemia or degradation in blood glucose control may occur during and after physical exercise (1–3). This may be avoided in patients with good glycemic control by decreasing insulin doses and/or ingesting carbohydrate. Although most sport activities involve intense muscle exercise, current recommendations are based on studies on moderate exercise (4). We therefore investigated the effect of a drastic reduction in insulin dose before a 60-min high-intensity cycle exercise in 12 subjects with uncomplicated type 1 diabetes (age 32 ± 7 years, BMI 23 ± 7 kg/m2, HbA1c 7.2 ± 3.8%, and V o2max 40 ± 27 ml · min−1 · kg−1 [mean ± SD]). Six patients were treated with three daily injections (regular insulin in the morning and at noon and mixed …