Inclusion Criteria:  Heart failure patients  Age ≥40 yrs Stable chronic heart failure Systolic dysfunction determined by cardiac MRI with left ventricle ejection fraction 40% or less  Healthy Volunteers  Age ≥40 yrs No diagnosed heart failure or sarcopenia  Exclusion Criteria:  Heart failure patients  • Advanced liver disease, advanced cancer, advanced chronic obstructive pulmonary disease  Healthy volunteers (controls)  Advanced liver disease, advanced cancer, advanced chronic obstructive pulmonary disease Contraindications to MRI Contraindications to MRI Heart pacemaker/defibrillator Electronic/implanted stimulators or devices, including deep brain stimulator, vagus nerve stimulator, bladder stimulator, spine stimulator, neurostimulators; implanted electrodes or wires Cochlear implant or other ear implants Implanted drug pumps (insulin, narcotic/pain medications, drugs to treat spasticity) Programmable shunt Aneurysm clips and coils Stents Filters (for example, blood clot filters) Metal fragment in body or eye (eg, BBs, bullets, shrapnel, metal pieces or shavings)