Abstract Exercise training produces substantial health benefits, summarized in the Physical Activity Guidelines Advisory Committee Report and incorporated into the 2008 and 2018 Physical Activity Guidelines for Americans. Despite the well-known benefits, too few individuals adopt exercise as a health maintenance strategy. Thus, determining whether a relatively modest duration of exercise training in middle age can lead to sustained health benefits as individuals progress into older age groups (legacy effects) is of public health and clinical importance. As the parent R21 seeks to determine whether a relatively short six-month exercise intervention (STRRIDE-PD) produces sustained, legacy health effects ten years later, this proposed supplement will simultaneously investigate in a community-based cohort (UNC Alumni Heart Study; UNCAHS) whether self- directed exercise behavior is also related to long-term health status. Thus, the proposed supplement will enhance the significance of the parent R21 by extending the generalizability of the findings to individuals who would not have qualified for the STRRIDE studies due to either their risk factor or medical history status. Matched to the STRRIDE-PD Reunion cohort, 200 age- and gender-matched participants from the UNCAHS who have reported on their unsupervised exercise behavior will be invited to complete parallel assessments of cardiorespiratory fitness and cardiometabolic risk factors. Integrating the UNCAHS via the supplement will allow us to compare the legacy effects of supervised exercise training programs to self-directed exercise in a community-based cohort. Taken together, the parent R21 and the proposed supplement will provide unique insight into the biological and psychological underpinnings of physical activity behavior in midlife and long-term cardiometabolic health status.