Nine T1DM patients (5M/4F; 35–65 years; HbA1c 54±13 mmol·mol-1) performed, under free-life conditions, a 3-h walk at 30% heart rate reserve while insulin concentrations, whole-body carbohydrate oxidation rates (determined by indirect calorimetry) and supplemental carbohydrates (93% sucrose), together with glycemia, were measured every 30 min. Here, INS is linked to type 1 diabetes mellitus.