Resistance Exercise in Already-Active Diabetic Individuals (READI): Study rationale, design and methods for a randomized controlled trial of resistance and aerobic exercise in type 1 diabetes

The Resistance Exercise in Already Active Diabetic Individuals (READI) trial aimed to examine whether adding a 6-month resistance training program would improve glycemic control (as reflected in reduced HbA1c) in individuals with type 1 diabetes who were already engaged in aerobic exercise compared to aerobic training alone. After a 5-week run-in period including optimization of diabetes care and low-intensity exercise, 131 physically active adults with type 1 diabetes were randomized to two groups for 22 weeks: resistance training three times weekly, or waiting-list control. Both groups maintained the same volume, duration and intensity of aerobic exercise throughout the study as they did at baseline. HbA1c, body composition, frequency of hypoglycemia, lipids, blood pressure, apolipoproteins B and A-1 (ApoB and ApoA1), the ApoB-ApoA1 ratio, urinary albumin excretion, serum C-reactive protein, free fatty acids, total daily insulin dose, health-related quality of life, cardiorespiratory fitness and musculoskeletal fitness were recorded at baseline, 3 (for some variables), and 6 months. To our knowledge, READI is the only trial to date assessing the incremental health-related impact of adding resistance training for individuals with type 1 diabetes who are already aerobically active. Few exercise trials have been completed in this population, and even fewer have assessed resistance exercise. With recent improvements in the quality of diabetes care, the READI study will provide conclusive evidence to support or refute a major clinically relevant effect of exercise type in the recommendations for physical activity in patients with type 1 diabetes.