Effect of High-Intensity Exercise to Attenuate Cognitive Function Limitations and Train Exercise Habits in Older People Living With HIV

Inclusion Criteria: * Confirmed HIV * Sedentary lifestyle, defined as self-reported PA that breaks a sweat \<3 days/week, with no regular resistance exercise for 3 months preceding study; * Fatigued (≥2.0 on either of the first two screening items on the HIV-Related Fatigue Scale) * On a current, contemporary ART regimen for \>=12 months; * HIV-1 RNA \<200 copies/mL in the past 12 months (assessed via medical records) * Willing to engage in a supervised exercise program 3 times/week for 4 months * Cell phone or email to accept messages * Weight \<450 lbs * Medical clearance by study healthcare professional Exclusion Criteria: * Weight over 450 pounds * Use of sex hormone therapy, if on for ≤3 months (stable doses for \>3 months will be permitted) * Use of other hormone replacement, if on for ≤ 3 months (stable doses \>3 months will be permitted) * Anemia (Hemoglobin ≤9 g/dL for women or ≤10 g/dL for men) due to contribution to fatigue, * Diagnosis of mitochondrial disease, * Active substance abuse or other factors that could prevent compliance or safety with study visits, at the discretion of the site investigator, * Reasons for medical exclusion, as determined by Nurse Practioner: 1. Uncontrolled hypertension defined as resting systolic blood pressure \>150 mmHg or diastolic blood pressure \>90 mmHg; participants who do not meet these criteria at first screening will be reevaluated, including follow-up evaluation by their primary care provider with initiation or adjustment of anti-hypertensive medications, 2. Unstable ischemic heart disease (e.g., angina, ST segment depression) or serious arrhythmias at rest or during the graded exercise test without negative follow-up evaluation will be cause for exclusion; follow-up evaluation must include diagnostic testing (e.g., thallium stress test) with interpretation by a cardiologist, 3. New York Heart Association Class III or IV congestive heart failure, clinically significant aortic stenosis, uncontrolled angina, or uncontrolled arrhythmia, 4. Pulmonary disease requiring the use of supplemental oxygen at rest or with physical exertion, 5. Malignancy requiring chemotherapy or radiation therapy within 24 weeks prior to enrollment, 6. Poorly controlled diabetes, as evidenced by hemoglobin A1c \> 8.5, documented within 6 months of study visit or current use of insulin, 7. Surgery/trauma/injury/fracture within 24 weeks prior to enrollment that, in the opinion of the study clinician, may impact a subject's baseline functional testing and ability to exercise, 8. Balance impairments that may impact functional testing and ability to safely exercise as reported by the participant or in their medical record, 9. Orthopedic problems (e.g., severe osteoarthritis, rheumatoid arthritis) that greatly limit the ability to perform moderate intensity resistance exercise (e.g., unable to be properly positioned in exercise equipment or to have severely restricted range of motion even after modifications have been made), 10. Persons who, in the judgment of the study clinician, appear to have unstable health or are incapable of safely participating in the exercise intervention.