PRIME HFrEF: Novel Exercise for Older Patients With Heart Failure With Reduced Ejection Fraction

This study is trying to find out whether performing a hybrid aerobic-resistance exercise training program (titled PRIME: Peripheral Remodeling via Intermittent Muscular Exercise) results in better health outcomes than the traditional exercise training program (called COMBO) that is used in individuals with heart failure with reduced ejection fraction (HFrEF). Participants will be randomized (like the flip of a coin) to either PRIME (investigational) or the traditional exercise program (standard of care).