In the early 20th century R. Tait McKenzie began the process of using exercise as an active treatment for disease and injury rather than to merely maintain heath (1). Exercise therapy is a structured and repetitive physical activity that is utilized to improve function, improve fitness or provide rehabilitation. This category includes aerobic, anaerobic stretching and water exercise, etc.
(1) Moore GE. The role of exercise prescription in chronic disease. Br J Sports Med 2004 Feb;38(1):6-7.