Molecular evidence that exercise training has beneficial effects on cardiac performance

Numerous epidemiological and observational studies demonstrate that there is an inverse relationship between physical activity and risk of cardiovascular disease (1). Recently a few randomized controlled trials revealed that exercise training is not only effective as primary prevention, but also in the secondary prevention and thus can be viewed as a "medication" that should be taken on a regular basis by a patient with cardiovascular disease. Exercise in Left Ventricular Dysfunction (ELVD) trial in a small group of 77 patients with <40% ejection fraction after a first Q-wave myocardial infarction showed that a 6-month exercise training program prevented deleterious LV remodeling (2). The Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION) trial, enrolling 2,331 outpatients with stable systolic heart failure demonstrated that exercise training was associated with an 11% reduction in combined all-cause death or hospitalization (P=0.03) (3). A meta-analysis of exercise training trials in patients with chronic heart failure, majority of whom had a history of myocardial infarction, revealed that exercise training significantly reduced deaths and hospital admissions (4). Thus exercise training is recommended as part of a comprehensive approach to the patient with stable chronic heart failure (1).