Inclusion Criteria:

• • See NCT06404047 for RECOVER-ENERGIZE: Platform Protocol level inclusion and exclusion criteria which applies to this appendix

Exclusion Criteria:

• 1. Known pre-existing postural orthostatic tachycardia syndrome, not related to SARS-CoV-2 infection
• 2. Known uncontrolled hypertension (blood pressure \[BP\] ≥ 160/100 mmHg at rest)
• 3. Any of the following within 4 weeks of enrollment - acute myocardial infarction, unstable angina, uncontrolled arrhythmias causing symptoms or hemodynamic compromise, acute myocarditis or pericarditis, uncontrolled acutely decompensated heart failure (acute pulmonary edema), acute pulmonary embolism, suspected dissecting aneurysm, severe hypoxemia at rest, thromboembolic event(s), any acute or chronic disorder that may affect exercise capacity or be aggravated by exercise (e.g., infection, exercise induced syncope, thyrotoxicosis, unable to cooperate)
• 4. Score of 2 or greater for both frequency and severity for any of the first 5 questions on the Screening mDSQ-PEM AND answer of 'YES' to either item 7 or 8 on the Screening mDSQ-PEM, or response of \> 14 hours in item 9 OR Score of 3 or greater on any severity question (regardless of frequency) AND answer of 'YES' to either item 7 or 8 on the Screening mDSQ-PEM, or response of \> 14 hours in item 9 OR Score of 3 or greater on any of the severity questions on the mDSQ-PEM 48-72 hours following the Screening ISWT test
• 5. A selection of ≥ 8 on question 1 or ≥ 9 on question 3 of the OH Activity Scale from the mOHQ
• 6. Engaged in purposeful moderate or greater intensity exercise with the intent to improve one's health 2 or more times per week over the 30 days prior to informed consent
• 7. Inability to walk