Background: Social ecological models suggest that conditions in the social and physical environment, in addition to individual factors, play important roles in health behavior change. Using structural equation modeling, this study tested a theoretically and empirically based explanatory model of physical activity to examine theorized direct and indirect effects of individual (e.g., motivation and self-efficacy), social environmental (e.g., social support), and physical environmental factors (e.g., neighborhood quality and availability of facilities).
Method: A community-based sample of adults (N = 910) was recruited from 2 public health centers (67% female, 43% African American, 43% < $20,000/year, M age = 33 years) and completed a self-administered survey assessing their current physical activity level, intrinsic and extrinsic motivation for physical activity, perceived social support, self-efficacy, and perceptions of the physical environment.
Results: Results indicated that (a) perceptions of the physical environment had direct effects on physical activity, (b) both the social and physical environments had indirect effects on physical activity through motivation and self-efficacy, and (c) social support influenced physical activity indirectly through intrinsic and extrinsic motivation. For all forms of activity, self-efficacy was the strongest direct correlate of physical activity, and evidence of a positive dose-response relation emerged between self-efficacy and intensity of physical activity.
Conclusions: Findings from this research highlight the interactive role of individual and environmental influences on physical activity.