Exercise is Medicine—The Importance of Physical Activity, Exercise Training, Cardiorespiratory Fitness, and Obesity in the Prevention and Treatment of Type 2 Diabetes

Type 2 diabetes has reached epidemic proportions worldwide and is associated with increased risk for cardiovascular diseases and premature mortality. Diet and physical activity (PA)-based lifestyle interventions have been shown to prevent progression to type 2 diabetes in patients at high risk. Regular PA substantially reduces the risk for type 2 diabetes and a high level of PA is associated with a substantial reduction in type 2 diabetes risk. In addition, there is strong evidence suggesting a steep inverse relationship between both PA and cardiorespiratory fitness (CRF) and mortality in patients with type 2 diabetes. Of particular concern is the dramatic, steep increase in mortality among patients with low CRF. An important point is that obese individuals who are at least moderately fit have a lower mortality risk than those who are normal weight but unfit. A large body of evidence demonstrates that exercise improves glycemic control in type 2 diabetes; the greatest improvements are achieved with combined aerobic and resistance training. A primary goal of public health strategies is to promote PA and move patients out of the least fit, high-risk cohort by increasing PA among the least active. Any plan to deal with the global epidemic of type 2 diabetes must give major attention to low PA and how this can be reversed in the general population.