Traditionally exercise training was considered contraindicated in heart failure patients. However, during the last 15 years numerous small studies have demonstrated that training is safe in stable heart failure patients and that this intervention improves quality of life in this population. The beneficial effects include improved autonomic balance, reduced neurohumoral activation and reduced inflammatory response in addition to the direct effect on exercise capacity. Pooling of the available data from small randomized studies confirms the positive effect of training on morbidity, and also suggests that this type of intervention improves survival. Large scale studies are on-going to confirm the beneficial effects of training on mortality. This paper reviews the effects of exercise training in patients with the syndrome of heart failure and discusses the different types of training protocols and the tools for assessing the training effect in this population.