- Heart failure (HF) patients are often counseled to limit their physical activity, however, this advice may not be appropriate. Data has accumulated supporting the effectiveness of exercise training to improve fitness levels and symptoms. There are also data suggesting that training may reduce mortality and morbidity in HF patients. Studies have demonstrated that exercise training can be performed safely in appropriately evaluated HF patients. The literature would support the prescribing of exercise training to NYHA II-III HF patients. Consideration could also be given to training stable NYHA IV HF patients who are not symptomatic at rest. This article reviews the effects of exercise training on clinical outcomes and addressing the safety of exercise training and the indications for training in HF patients.