['The purpose of this study was to investigate the effects of physical exercise on the functional capacity and quality of life in heart failure patients.', 'Forty-two patients of both sexes with heart failure of NYHA class II and III with different etiologies were randomly divided into untrained or trained groups. The six-month exercise program consisted of aerobic training, muscle strength training, agility and joint flexibility activities. Physical fitness was evaluated by testing the performance on these trained components. Quality of life was evaluated by scored answers to a standardized questionnaire involving multiple domains.', 'Baseline values did not differ between groups. Improvement in the trained group was identified in all components of functional capacity when compared to the untrained group (p<0.001). Quality of life improved in the trained patients concerning physical, psychological, social and environmental domains (p<0.001), whereas no significant change was found in the untrained patients.'] Does physical exercise improve the functional capacity and quality of life in patients with heart failure?