The Impact of a Multidimensional Physical Activity Intervention on Glycemic Control in Type 1 Diabetes

INTRODUCTION: Type 1 diabetes is characterized by hyperglycemic episodes influenced by diet, sleep quality, chronotype and physical activity, among others. While aerobic exercise is known to improve glycemic control, its effect on blood glucose regulation remains underexplored. Thus, this case study aimed to evaluate the effects of a prolonged and differentiated (indoor and outdoor exercise) physical activity intervention on glycemic control in an individual with type 1 diabetes. METHODS: The participant (age: 23years; weight: 95kg; height: 1.90m; Body Mass Index (BMI): 26.3kg/m2; waist to hip ratio: 0.98; basal metabolic rate: 2015kcal; Heart Rate Maximum (HRmax): 197beats·min-1) completed two outdoor session (~3800m) and two indoor session with self-selected speed, in the initial 2-min stage, at 0% grade slope. The grade increased 2% each stage during the uphill phase until reaching volitional fatigue, followed by a 2% decrease at each stage during the downhill phase until returning to 0% grade. Blood pressure was assessed before and after each session. Daily nutrition intake, insulin intake and blood glucose were continuously monitored. Dietary adherence (PREvención con DIeta MEDiterránea), sleep quality (Pittsburgh Sleep Quality Index), chronotype (Morningness–Eveningness Questionnaire), and physical activity levels (International Physical Activity Questionnaire) were assessed before each session. Physical Activity Enjoyment Scale was used to measured enjoyment after each session. RESULTS: The sessions were completed in ~44 and ~39 minutes with the participant achieving the 84% (outdoor) and 96% (indoor) of his theoretical HRmax. The intervention resulted in glycemic improvements, with time spent in hyperglycemia (>250mg/dL) decreasing from 56.46% to 0%, while time in the normal range (70–180mg/dL) increasing to 63.96%. A 47% reduction in insulin units showed that also insulin sensitivity improved. CONCLUSION: Despite differences in intensity, indoor and outdoor activities yielded comparable benefits, with outdoor activities perceived as more enjoyable, positively impacted glycemic control, advocating for tailored strategies in diabetes care.