Exercise has been recommended as a treatment for type 2 diabetes for centuries. It is only in the last 2 decades, however, that the powerful role exercise and physical activity play in treating and preventing type 2 diabetes has been fully appreciated. The molecular understanding of exercise in relation to type 2 diabetes is evolving, as is knowledge about the best mode, frequency, and duration of exercise to treat and prevent this disorder. In addition, there is a growing appreciation for the role of diverse types of exercise, such as strength training, in type 2 diabetes. Although people with diabetes-related complications have been discouraged from exercising in the past, there are a variety of activities that allow for safe exercise in a supervised setting. As such, individualized exercise training can become an integral part of the treatment plan for the management of type 2 diabetes.