Inclusion Criteria:  Participants age 18 years or over. Able to give informed consent Good spoken and written English History of COVID-19 and experiencing prolonged symptoms. Community ambulant Able to mobilise independently (with or without aid). Able to transfer with minimal assistance of one person from lying to standing. Patients with a history of COVID-19 who now present with a negative swab  Exclusion Criteria:  Unwilling to participate Aged less than 18 for TROPIC. Persons with cognitive impairment / dementia that would render them unable to give informed consent. Persons who are pregnant Persons who require more than min assistance of one person to transfer from lying to standing. Persons who are not independently mobile. Persons with an acute illness. Participants with skin allergies to adhesive tapes. Participants with upper limb lymphoedema (cuff-site) Participants registered as blind or partially blind. Persons for whom tilt testing and exercise testing is contra-indicated as per results of the Physical Activity Readiness Questionnaire or anyone falling under the absolute contra-indications to exercise testing as per the American Heart Association's Guidelines for Exercise testing, including: 1. Acute myocardial infarction within 2 days (or any other acute cardiac event) 2. Unstable angina 3. Uncontrolled cardiac arrhythmias causing symptoms or hemodynamic compromise 4. Uncontrolled symptomatic heart failure 5. Symptomatic sever aortic stenosis 6. Suspected or known dissecting aneurysm 7. Acute myocarditis or pericarditis 8. Acute pulmonary embolus or pulmonary infarction 9. Acute systemic infection, accompanied by fever, body aches or swollen lymph glands, 10. patients in whom low organ perfusion pressures may compromise end artery supplied tissue, 11 severe left ventricular outflow obstruction, 12. critical mitral stenosis.