The Built Environment as a Determinant of Physical Activity: A Systematic Review of Longitudinal Studies and Natural Experiments

Background Physical inactivity is a global problem that increases the risk of many chronic diseases and shortens life expectancy. The built environment contributes to physical inactivity through accessibility of amenities and transportation patterns. With better urban planning, cities could be designed to enhance active transportation and population health on a permanent basis. Purpose We conducted a systematic review to identify determinants of the built environment associated with physical activity and to evaluate how changes in the built environment are associated with changes in physical activity. Methods We searched six databases, from the inception of each until December 2015, for studies that were written in English, used longitudinal before-and-after design and assessed changes in both the built environment and physical activity. A total of 21 prospective cohort studies and 30 natural experiments were included in the review. Results The review showed that changes in the built environment and in physical activity were related. A higher objective accessibility and new infrastructure for walking, cycling and public transportation were associated with increased overall and transportation-related physical activity. Some evidence was found for perceived aesthetics and safety as determinants of physical activity. Conclusions Improved objectively measured accessibility of different type of destinations and public transportation and land use mix were associated with increased physical activity. Creating new infrastructure for walking, cycling and public transportation could induce demand for walking and cycling. The results support the creation of compact and diverse residential areas and investments into infrastructure that encourage active modes of transportation.