Exercise in cardiac rehabilitation.

Introduction The notion that exercise is dangerous for patients with heart disease dogged the use of such treatment for the first half of the twentieth century. It was a further 30 years before exercise became accepted in rehabilitation. The controversy is made more diYcult by the fact that exercise may be dangerous for some patients in some circumstances. Exercise is now widely believed to benefit a wide variety of patients with heart disease. However, when it is used to treat cardiac patients, exercise should be approached like any other treatment and thought given to the indications, the contraindications, the mode of action, the type, the dose, the duration of treatment, the expected benefits, and the side eVects.