Effects of High-Intensity Interval Training and Exercise Snacking on Glycemic Control and Cardiorespiratory Fitness in Adults With Type 2 Diabetes Mellitus

This randomized controlled trial investigates whether two time-efficient forms of high-intensity exercise, high-intensity interval training (HIIT) and exercise snacking, improve glycemic control, cardiorespiratory fitness and other cardiometabolic risk factors in adults with type 2 diabetes mellitus. Over 12 weeks, participants were allocated to HIIT, exercise snacking, or a non-exercise control group. The study addresses two questions: whether each exercise modality improves these outcomes relative to no exercise, and whether accumulating vigorous exercise in brief bouts throughout the day produces adaptations comparable to those of conventional interval training performed in a single session.

Inclusion Criteria: * Adults aged 18-65 years * Diagnosis of type 2 diabetes mellitus for at least 6 months, based on standard criteria (fasting plasma glucose ≥7.0 mmol/L \[≥126 mg/dL\] and/or HbA1c ≥6.5% \[≥48 mmol/mol\]) * Physically inactive according to the International Physical Activity Questionnaire (IPAQ): \