Inclusion Criteria:
1. Age \>=60 years old
2. Ejection Fraction \>=45%
3. In the hospital setting \>24 hours for the management of acute decompensated heart failure (ADHF), or diagnosed with ADHF after being hospitalized for another reason. ADHF will be confirmed by the site physician, and will be defined according to the Food and Drug Administration (FDA) definition of hospitalized heart failure as a combination of symptoms, signs, and HF-specific medical treatments, and requires that all 4 of the following are met:
* At least 1 symptom of HF which has worsened from baseline: a. dyspnea at rest or with exertion; b. exertional fatigue; c. orthopnea; d. paroxysmal nocturnal dyspnea (PND)
* At least 2 of the following signs of HF: a. Pulmonary congestion or edema on physical exam (rales or crackles) or by chest X-ray; b. Elevated jugular venous pressure or central venous pressure \>=10 mm Hg; c. peripheral edema; d. wedge or left ventricular end diastolic pressure \>=15 mmHg; e. rapid weight gain (\>=5 lbs.); f. Increased b-type natriuretic peptide (BNP) (\>=100 pg/ml) or N-terminal prohormone BNP (\>=220pg/ml)
* Change in medical treatment specifically targeting HF, defined as change in dose or initiation of or augmentation of at least 1 of the following therapies: a. diuretics; b. vasodilators; c. other neurohormonal modulating agents, including angiotensinconverting enzyme inhibitors, angiotensin II receptor blockers (with or without neprilysin inhibitor), beta-blockers, aldosterone inhibitors, direct renin inhibitors, or sodium-glucose co-transporter-2 inhibitors
* The primary cause of symptoms and signs is judged by the investigator to be due to HF
4. Adequate clinical stability to allow participation in study assessments and the intervention Independent with basic activities of daily living, including the ability to ambulate independently (with or without the use of an assistive device) prior to admission
5. Able to walk 4 meters (with or without the use of an assistive device) at the time of enrollment
Exclusion Criteria:
1. Acute myocardial infarction within the past 3 months, or planned coronary artery intervention (percutaneous or surgical) within the next 6 months (Note: given that cardiac biomarkers such as troponin are frequently elevated in HF patients, the diagnosis of acute myocardial infarction should be based on clinical diagnosis, not biomarkers alone)
2. Severe aortic or mitral valve stenosis
3. Severe valvular heart disease with planned intervention within next 6 months
4. Known pericardial constriction, genetic hypertrophic cardiomyopathy, or infiltrative cardiomyopathy including amyloid heart disease (amyloidosis)
5. Planned discharge other than to home or a facility where the participant will live independently
6. Terminal illness other than HF with life expectancy \<1 year
7. Impairment from stroke or other medical disorders that preclude participation in the intervention
8. Known dementia by medical record documentation, OR patients with Montreal Cognitive Assessment (MoCA) \<=18 AND without social support, OR MoCA \<10 regardless of social support
9. Advanced chronic kidney disease defined as estimated glomerular filtration rate \<20 mL/min/1.73 m2 or on chronic or intermittent dialysis or dialysis anticipated within the next 6 months
10. Already engaging in regular moderate to vigorous exercise conditioning defined as \>30 minutes per day, \>= twice per week consistently during the previous 6 weeks
11. Enrollment in a clinical trial not approved for co-enrollment
12. High risk for non-adherence as determined by screening evaluation
13. Inability or unwillingness to comply with the study requirements or give consent
