COVID-19 Health Adjustments in Nutrition, General Wellness, and Exercise

The investigator will be assessing whether prior severity of COVID-19 or (Post-acute Sequelae of SARS-CoV-2 Infection) PASC is associated with reduced physical activity and cardiorespiratory fitness, impaired blood pressure regulation, worse sleep, or heightened mental stress. Participants will report to the laboratory for two visits.

Visit 1 will be comprised of participant consent, screening, and completing questionnaires surrounding sleep, stress and mental health, food security, and habitual beverage intake. Visit 1 will take approximately 2 hours in total. Participants will be asked to read the consent form at this time and be encouraged to ask any questions. Participants can then: 1) sign the consent form; 2) take it home for further consideration; or 3) decide not to participate. Participants will be screened for eligibility once written informed consent has been given. At the conclusion of the first visit, participants will be given devices to track ambulatory blood pressure for 24 hours, physical activity and sleep for ~14 days, and diet for ≥3 days (i.e., 2 week days and 1 weekend day). 24 hours before the experimental visits, participants will be given a 24-hour urine collection container to measure urine volume, urine electrolyte concentrations, urine electrolyte excretion, and urine osmolality for eventual assessment of biomarkers of kidney function and kidney injury.

Visit 2 will be an experimental visit where each participant will undergo applied physiology measures, body composition, and exercise testing. During experimental visits, a blood draw will take place to assess changes in plasma electrolyte concentration, osmolality, hemoglobin, and hematocrit, and coded samples will be stored for future inflammation measures (e.g., CRP and IL-6) in addition to isolating peripheral blood mononuclear cells (PBMCs) for studying immune cell phenotype. Participants will then have rested BP assessed. Arterial stiffness will be measured using noninvasive tonometry techniques (Pulse Wave Analysis and Pulse Wave Velocity via SphygmoCor XCEL). We will use a hand-in cold-water test (described below) to assess sympathetic nervous system excitation. The cold pressor test is where participants will submerge their hand into an ice-cold bucket of water for three minutes to elicit a sympathetic nervous system stress response. Concurrently, BP reactivity will be assessed using a cold pressor test while participants engage in submaximal exercise on a stationary bicycle. Blood pressure reactivity will be measured at the finger using a finger-specific blood pressure cuff that will measure BP on a beat-to-beat basis. A total-body dual-energy X-ray absorptiometry (iDXA) scan will be used to assess bone mineral density, lean muscle mass, fat mass, and body fat percentage. Participants will finish the visit by completing a submaximal ramp cycling test on an electronically braked cycle ergometer to assess cardiovascular fitness. The test will begin at a low workload and increase incrementally every 30 minutes until the participant reaches 70% of their estimated maximal heart rate. Heart rate, workload, and perceived exertion will be recorded throughout to estimate cardiorespiratory fitness.

Collectively, these measures will enable the investigators to determine the study objectives pertaining to whether prior COVID-19 severity or PASC impacts cardiovascular health, which have important public health implications.