Physical Activity in Older Adults: an Ecological Approach

Studies identifying correlates of physical activity (PA) at all levels of the ecological model can provide an empirical basis for designing interventions to increase older adults' PA. Applying ecological model principles, this study concurrently examined individual, psychosocial, and environmental correlates of older adults' PA to determine whether built environment factors contribute to PA over and above individual/demographic and psychosocial variables. Using a cross-sectional observational design, 726 adults, aged >66 years, were recruited from two US regions. Explanatory variables included demographics, self-efficacy, social support, barriers, and environmental variables measured by using geographic information systems (GIS) and self-report. Outcomes included reported walking for errands and leisure/exercise and accelerometer-measured daily moderate to vigorous PA (MVPA). Analyses employed mixed-model regressions with backward elimination. For daily MVPA, the only significant environmental variable was GIS-based proximity to a park (p < 0.001) after controlling for individual/demographic and psychosocial factors. Walking for errands was positively related to four environmental variables: reported walking/cycling facilities (p < 0.05), GIS-based intersection density (p < 0.01), mixed land use (p < 0.01), and private recreation facilities (p < 0.01). Walking for leisure/exercise was negatively related to GIS-based mixed land use (p < 0.05). Non-Hispanic white race/ethnicity, self-efficacy, and social support positively related to all three PA outcomes (p < 0.05). Correlates of older adults' PA were found at all ecological levels, supporting multiple levels of influence and need for multilevel interventions. Environmental correlates varied by PA outcome. Walking for errands exhibited the most environmental associations.