The built environment is an important determinant of physical activity behavior. It can provide the opportunities, support, and choices or barriers to being physically active. Over the past 60 years the proliferation of private car ownership has led to lower-density land use and a decline in incidental daily physical activity. A wide range of labor-saving devices and a shift in employment from more physically active to less active roles has also contributed to the decline in physical activity.

The built environment includes land-use patterns, transport systems, urban design, green spaces and all buildings and spaces that are created by people (including schools, homes, workplaces and recreational areas). Most sustainable physical activity occurs during everyday activities within the built environment rather than for leisure. Hence the qualities of the built environment have a significant role in facilitating more active lifestyles by reducing barriers to, and creating opportunities for physical activity. There is increasing evidence that adapting the built environment has the potential to encourage increased physical activity to levels that are beneficial to health.

Leisure physical activity may be most affected by access to, and characteristics of public and private recreation facilities. Transportation physical activity may be most related to the proximity and directness of routes from home to destinations (known as walkability) as well as characteristics of the walking and cycling infrastructure, including sidewalks, bicycle lanes, and trails.