Clinical Research Directory

Inclusion Criteria: * Participants who are \>= 60 years of age * HIV serostatus positive participants on stable antiretroviral therapy (ART) (no regimen change in last month) with undetectable HIV viral load (\<100 copies). * HIV serostatus negative participants Exclusion Criteria: * Unable to understand the risks, benefits, and alternatives of participation and give meaningful consent * Contraindications to MRI * Significant cardiovascular, pulmonary or musculoskeletal or orthopedic disease that significantly limits exercise capacity * Significant lower extremity peripheral vascular disease. * Weight greater than 350 lbs * Cognitive or speech impairments that would limit completion of questionnaires or fatigue reporting.