Brief Summary: Alcohol use disorder (AUD) is a significant and costly public health problem that affects one-third of the U.S. population in their lifetime. Specifically, unhealthy alcohol use is common among persons living with HIV (PLWH) and increases the risk of developing negative outcomes. Antiretroviral therapy (ART) has shown increasing life expectancy and decreased HIV-related deaths, leading to a growing older adult HIV population. Yet, HIV accelerates the aging process and increases the risk for numerous chronic health conditions that compromise physical and mental health functioning and quality of life. Thus, PLWH continue to have shorter life expectancies relative to the general population and these multimorbidities explain this increased risk. In this context, unhealthy alcohol use among PLWH can further increase the risk for negative outcomes. Physical activity (PA) interventions can be used as an effective way to address unhealthy alcohol use among PLWH. Previous PA interventions have shown low generalizability and high loss to follow-up. Therefore, an intervention that is home-based, including lifestyle physical activity (LPA) with mobile health-delivered components is designed following the physical activity (PA) paradigm. Participants in this randomized controlled trial will be assigned to one of two study arms -- either the LPA or Fitbit Only intervention - both lasting 12-weeks. Both study arms will utilize a Fitbit to track daily step counts. In addition to utilizing a Fitbit, the LPA arm will receive 7 LPA sessions with a trained interventionist to assist in adding LPA to the participant's routine. The Fitbit only arm will receive only brief check-in phone calls and only related to assisting with any Fitbit functioning issues. Follow-up assessments will take place at 3 and 6 months.