High-Intensity Exercise to Attenuate Limitations and Train Habits in Older Adults With HIV

This is a multi-site, randomized, single-blind (researchers), active treatment concurrent control trial with individuals aged 50 and older living with HIV who experience fatigue and live a sedentary lifestyle. The overall goals of this proposal are to determine whether high-intensity interval training (HIIT) can overcome physical function impairments and increased fatigue (Aim 1) and impairments in mitochondrial bioenergetics of older people with HIV (PWH) to a greater extent than continuous moderate-intensity exercise (CME) (Aim 2). The investigators further seek to determine whether a biobehavioral coaching intervention following either HIIT or CME can promote long-term adherence to physical activity (Aim 3), a crucial component of the sustainability of the intervention. This study will enroll 100 participants in Aurora, Colorado and Seattle Washington. Physical function will be measured by a 400-meter walk test (400MWT) and the short physical performance battery in its original (SPPB) and modified (mSPPB) forms. Fatigue will be measured by the Lee Fatigue Scale (LFS) - a 7-item visual analog self-report scale that asks participants to rate from 0 to 10 how they feel "right now." Mitochondrial bioenergetics will be assessed through blood draws, muscle biopsies and mitochondrial assays. Adherence to physical activity (PA) will be analyzed through ActiGraphy - measurement of PA duration and intensity on three planes of movement captured through PA monitors. Finally, perceptions of PA will be determined through the analysis of qualitative interviews. The hypotheses are that that investigators will see greater changes in mitochondrial bioenergetics with HIIT (AIM 1), and that these changes will be related to improved physical function and fatigue (Aim 2). The investigators expect that HIIT will result in greater exercise satisfaction and likelihood of long-term continuation of exercise (Aim 3). Using a coaching intervention for self-directed exercise that combines motivational interviewing and personalized support during the maintenance phase (Aim 3), the investigators seek to develop the ideal "cocktail" to promote healthspan among older PWH in the current era of ART.