Adults with Alzheimer's disease and related dementia (ADRD) and their caregivers represent a sizeable and underserved segment of the population with low levels of moderate physical activity (MPA). Options for increasing MPA in community dwelling adults with ADRD and their caregivers are limited. A home-based physical activity intervention delivered remotely via video conferencing to groups of adults with ADRD and their caregivers (RGV), represents a potentially effective approach for increasing MPA in this group. We will conduct an 18-month randomized trial (6 mos. Active intervention, 6 mos. Maintenance, 6 mos. no contact) to compare the effectiveness of the RGV approach with usual care, enhanced with caregiver support (EUC), for increasing MPA in 100 community dwelling adults with ADRD and their caregiver. The primary aim is to compare MPA (min/wk.), assessed by accelerometer, across the 6-mo. active intervention in adults with ADRD randomized to RGV or EUC. Secondarily, we will compare adults with ADRD and their caregivers randomized to RGV or ECU on the following outcomes across 18 mos.: MPA (min/wk.), sedentary time (min/wk.), percentage meeting 150 min/wk. MPA goal, functional fitness, activities of daily living, quality of life, residential transitions, cognitive function, and caregiver burden. Additionally, we will evaluate the influence of age, sex, BMI, attendance (exercise/support sessions), use of recorded sessions, self-monitoring, peer interactions during group sessions, caregiver support, type and quality of dyadic relationship, and number of caregivers on changes in MPA in adults with ADRD and their caregiver across 18 mos.