Background: A large proportion of adults are insufficiently physically active, and researchers have yet to determine the factors that enable individuals to maintain adequate levels of physical activity throughout adulthood. Purpose: This study sought to identify the key variables linked with consistent physical activity in adulthood as elucidated by a criterion sample of physically active adults. Methods: One hundred fifty-seven participants aged 24 and over who engaged in consistently high levels of physical activity rated the extent to which all of the potential correlates of physical activity identified in the research literature impacted their own activity level. Results: Participants reported that psychological, behavioral, and social/interpersonal factors disproportionately served as facilitators that increased their physical activity, when compared to environmental, policy, and demographic factors. Discussion: An ecological approach is necessary for understanding the physical activity behavior of individuals and the factors that support and inhibit adequate physical activity in adulthood. Translation to Health Education Practice: Efforts to address the widespread problem of physical inactivity should utilize an ecological approach by minimizing potential environmental barriers to physical activity while also targeting key individual and interpersonal factors that facilitate consistent engagement in physical activity throughout adulthood.