Physical Activity: The Role of Physical Activity and Fitness in the Prevention and Management of Type 2 Diabetes Mellitus

Abstract

More than 18 million people in the United States are estimated to have type 2 diabetes mellitus (T2DM). The prevalence of coronary heart disease has been estimated to be as high as 55% in adult diabetics, and cardiovascular disease (CVD) is responsible for at least two thirds of deaths in persons with T2DM. The metabolic syndrome, a clustering of interrelated risk factors, is predictive of T2DM and CVD and prevalent in the T2DM population. Increased aerobic fitness and/or physical activity (3 hours per week moderate activity and/or 1 hour per week vigorous activity) have been demonstrated to be protective of metabolic syndrome. Regular moderate to vigorous physical activity (150 minutes per week moderate activity and/or 90 minutes per week vigorous activity) has been shown to reduce the risk of developing T2DM, even in high-risk individuals. Sedentary behaviors such as television watching are associated with increased risk for T2DM independent of diet and physical activity levels. Glycemic control is related more to exercise intensity than volume. Exercise should be performed at least 3 days per week, with no more than 2 days between exercise bouts. Long-term weight loss may require 7 hours per week of moderate to vigorous exercise. Strength training, alone or in combination with regular aerobic exercise, has been shown to improve glycemic control, hypertension, and other T2DM-related risk factors. Unless specifically contraindicated, strength training is safe for persons with T2DM. The American Diabetes Association now recommends 150 minutes per week of moderate activity and/or 90 minutes per week of vigorous aerobic activity and strength training 3 days per week as part of a program to prevent or manage T2DM. Guidelines for preparticipation screening and consideration for specific conditions are also presented.