Chronic heart failure is a complex clinical syndrome characterized by multi-organ dysfunction and progressive functional deterioration. From the result of the literature, it is evident that the optimal care for heart failure is far from being reached, and exercise-based cardiac rehabilitation (Ex-CR) is a multidisciplinary therapeutic option with important clinical benefits. Longitudinal controlled studies and meta-analyses have demonstrated that Ex-CR improves functional capacity by 12-25%, and improves outcome by significantly decreasing hospital readmissions and cardiac mortality. These results have been obtained in patients with systolic dysfunction (HF-REF) with moderate aerobic endurance programs. More recently, greater improvements in functional capacity have been obtained even in older patients (>75 years) with high intensity interval training, but the number of patients is too small at present to reach definitive conclusion, and follow up is lacking. In diastolic heart failure (HF-PEF) improvements in functional capacity have been described in a total of 282 patients, with similar results as HF-REF but no evidence on outcome. Ex-CR programs are safe with a very low number of cardiac arrest (1/300,000 patient/hour) in different trials. Clinical benefits are the result of central and peripheral adaptations induced by exercise, which acts as a trigger of protein synthesis by specific genes activated by it. It is crucial to maintain a specific stimulus by repeating exercise bouts at least 2-3 times per week all life long, because after 2-3 weeks of inactivity functional adaptations disappear.