Physical Activity/Exercise and Type 2 Diabetes

For decades, exercise has been considered a cornerstone of diabetes management, along with diet and medication. However, high-quality evidence on the importance of exercise and fitness in diabetes was lacking until recent years. The present document summarizes the most clinically relevant recent advances related to people with type 2 diabetes and the recommendations that follow from these. Our recently published technical review on physical activity/exercise and type 2 diabetes (1) includes greater detail on individual studies, on prevention of diabetes, and on the physiology of exercise. The present statement focuses on type 2 diabetes. Issues primarily germane to type 1 diabetes will be covered in a subsequent technical review and ADA Statement. The levels of evidence used are defined by the ADA in ref. 2. Two randomized trials each found that lifestyle interventions including ∼150 min/week of physical activity and diet-induced weight loss of 5–7% reduced the risk of progression from impaired glucose tolerance (IGT) to type 2 diabetes by 58% (3,4). A cluster-randomized trial found that diet alone, exercise alone, and combined diet and exercise were equally effective in reducting the progression from IGT to diabetes (5). Therefore, there is firm and consistent evidence that programs of increased physical activity and modest weight loss reduce the incidence of type 2 diabetes in individuals with IGT. Boule et al. (6) undertook a systematic review and meta-analysis on the effects of structured exercise interventions in clinical trials of ≥8 weeks duration on HbA1c (A1C) and body mass in people with type 2 diabetes. Postintervention A1C was significantly lower in exercise than control groups (7.65 vs. 8.31%, weighted mean difference −0.66%; P < 0.001). In contrast, postintervention body weight did not differ between the exercise and control groups. Meta-regression confirmed that the beneficial effect of exercise on A1C …