The Transportation Research Board and the Institute of Medicine formed a 14-member committee to examine the connection between the built environment and the physical activity levels of the U.S. population.
Physical activity levels have declined sharply over the past half-century because of reduced physical demands of work, household management and travel together with increased sedentary uses of free time.
The built environment can facilitate or constrain physical activity.
The relationship between the built environment and physical activity is complex and operates through many mediating factors.
The available empirical evidence shows an association between the built environment and physical activity. However, investigators have conducted few studies capable of demonstrating a causal relationship, and evidence supporting such a relationship is currently sparse.
Weaknesses of the current literature include the lack of a sound theoretical framework, inadequate research designs and incomplete data.
The built environment in place today has been shaped by long-standing polices and the practices of many decision-makers.