The Role of Inter-Set Rest Periods in High-Intensity Interval Training on Acute Glucose and Insulin Sensitivity in Type I Diabetic Children: A Randomized Crossover Study

Aims: To investigate the impact of different inter-set rest periods on blood glucose levels and insulin sensitivity (IS) in children with type 1 diabetes. Study Design: An experimental randomized crossover trial. Place and Duration: Recruitment took place in the public health network of Rio Branco, Acre, Brazil. Methodology: Twenty subjects participated in three different HIIT protocols with varying rest intervals. The first protocol consisted of 20 seconds of exercise followed by 10 seconds of rest (HIIT20-10), the second with 20 seconds of rest (HIIT20-20), and the third with 60 seconds of rest (HIIT20-60). The exercise used in all protocols was the burpee, performed at maximum effort for a total of 12 minutes, comprising 24 sets. Blood glucose levels were measured through finger-prick tests before exercise, immediately after, and at 15, 30,60,and120 minutes post-exercise. For insulin sensitivity, 4 ml of venous blood was drawn before, immediately after, and at 30, 60, and 120minutes post-exercise, and the TyG Index was used to calculate IS. Results: No significant differences were observed between the HIIT20-20 and HIIT20-60 groups (p>0.05) regarding glucose levels. However, the HIIT20-10 protocol showed significantly lower glucose levels from 15 minutes to 120 minutes post-exercise (p<0.05) and improved IS at 60 minutes (p<0.05) and 120 minutes (p<0.01) after the exercise session. Conclusion: The inter-set rest period influences glucose metabolism during HIIT in children with type 1 diabetes.