Most recently, a specialized and carefully monitored exercise training and rehabilitation program has been recommended as add-on to medical treatment in patients with pulmonary arterial hypertension (class I, level of evidence A). Three prospective randomized, controlled trials, 10 prospective uncontrolled trials, 2 retrospective studies and 2 case series in more than 470 patients with severe pulmonary hypertension (PH) and right heart failure reported beneficial effects of a specialized exercise training and rehabilitation program, i.e. significant improvement in symptoms, exercise capacity, cardiorespiratory function and quality of life, compared with untrained controls. All training studies reported an acceptable safety profile, and some uncontrolled studies showed excellent 1- and 2-ye...