Exercise Training in Patients With Left Ventricular Assist Device

Inclusion Criteria: * chronic end-stage systolic heart failure * stable on left ventricular assist device, meaning 1. no major change in therapeutic regime within past 4 weeks: no new additional disease modifying drug (ACE inhibitor, ARB, sacubitril, beta-blocker), no change in disease modifying drug dosage more than 50% (excluded: diuretics), no initiation of a cardiac rehabilitation for a minimum of 4 weeks 2. post implantation ≥ 3 months 3. expected further period on the device for a minimum of 3 months after recruitment into the study * ability to complete the study in compliance with the protocol. * general ability of the patient to declare willingness to participate in the trial. * written informed consent Exclusion Criteria: * acute illness that does not allow exercise, including unstable heart failure, acute myocarditis, acute pericarditis, stroke * untreated life-threatening cardiac arrhythmias * uncontrolled hypertension * intracardiac thrombus * inability to perform cardiopulmonary exercise testing at least 1 minute at 20W * uncontrolled diabetes * uncontrolled kidney disease * recent embolism * concurrent, continuous, or intermittent dobutamine therapy * complex ventricular arrhythmia at rest or appearing with exertion * supine resting heart rate \> 100 beats per minute * severe pulmonary instability * hemodynamically relevant valvular disorders * significant change in cardiovascular medication within the previous 4 weeks (see inclusion criteria) * severe anemia (hemoglobin \<8 g/dl), however patients with moderate anemia (hemoglobin \<11 g/dl) may be recruited if clinically stable (investigator assessment) * clinically relevant musculoskeletal disease