This is a pilot, randomized, multicenter interventional trial of a combined preoperative oral nutritional support (ONS) and physical exercise therapy in patients planned for elective implantation of a left-ventricular assist device (LVAD). This pilot study pursues to demonstrate the feasibility and safety of a study protocol to optimize the patients' nutritional and physical state to reduce the number of postoperative complications and consequently to ameliorate the patients' outcome.

The oral nutrition supplementation will be started immediately after randomization and will be continued until surgery. The patients will receive a dosage of ONS adjusted to their nutritional risk. Regular monitoring of blood sugars, electrolytes, phosphate, and triglycerides will occur twice per week, as per standard protocol.

In-bed cycling will be started as soon as possible after randomization. Cycling sessions will be performed daily for 50 minutes, at least 5 times a week until surgery. Standard safety criteria will be assessed prior to initiating cycling treatments. The in-bed cycling will be performed passively or actively with graded increasing resistance. All cycling interventions will be performed under 1:1 supervision of medically trained study personnel while monitoring patient's heart rate, systolic and diastolic blood pressure and transcutaneous oxygen saturation of blood.

When evaluating the effect of a combined nutritional and exercise intervention, other important co-interventions should be standardized to reduce potential confounding of trial outcomes. All study patients should be fed with an oral diet that is in accordance to local standards, whereas it is strongly recommended to adhere to current clinical practice guidelines. Besides, the investigators highly encourage daily respiratory therapy in both groups plus mobilization as much as feasible.

All other key interventions during preoperative treatment will be standardized in accordance to the local clinical practice. Study teams will follow up on the patients on a daily base, documenting adherence with study interventions and key co-interventions.

Patients in the control group will not receive preoperative ONS. No bed cycling will be allowed from admission until surgery. Neither of these practices are the current standard of care in the participating unit.

Inclusion Criteria:

1. Given informed consent
2. Adult patients (≥18 years)
3. Patients undergoing elective LVAD implantation Additional cardiac surgery, such as bypass grafting, or valve repair is permitted

Exclusion Criteria:

1. Hospital admission <5 days prior to planned LVAD implantation
2. Patients on ECMO or INTERMACS<1
3. Patients already receiving nutrition support on hospital admission
4. Enteral nutrition is contraindicated.
5. Pregnant or lactating patients
6. Patients with clinical fulminant hepatic failure
7. Patients with cirrhosis Child's Class C Liver Disease
8. Patients with clinical kidney failure or requiring hemodialysis
9. Known allergy or intolerance to study nutrients
10. Intracranial or spinal process affecting motor function
11. Lower extremity impairments that prevent cycling
12. Disabling neuropsychiatric disorders or language barriers
13. Weight > 150 kg
14. Enrolment in an industry sponsored randomized trial within the last 30 days (co-enrolment in academic randomized trials will be considered on a case by case basis)

functional outcome assessor will be blinded to study group allocation