More research needed to explore links between physical activity and built environment

Research increasingly shows a link between physical activity and the "built" environment -- buildings, roads, parks, and other structures that physically define a community -- but more research is needed to assess whether the built environment affects people's actual levels of physical activity, says a new report from the National Academies' Transportation Research Board and Institute of Medicine.

This additional research could help clarify whether and to what extent the physical environment where Americans live and work contributes to the fact that more than half of the U.S. adult population falls short of meeting the U.S. surgeon general's guidelines for physical activity, said the committee that wrote the report.

"Inadequate physical activity is a major and largely preventable public health problem," said committee chair Susan Hanson, Landry University Professor, Clark University, Worcester, Mass. "We know from empirical evidence that the built environment can encourage some forms of physical activity, such as walking and cycling, for some population groups. But we don't know yet how important it is to meeting recommended levels of physical activity -- at least 30 minutes of moderate activity on five or more days per week -- or how much of a person's decision to be physically active depends on physical surroundings as opposed to personal inclination."

The well-established connection between physical activity and health justifies a continuing and more interdisciplinary research effort to study causal relationships between the built environment and physical activity, the committee said. The results of this research could provide guidance to policy-makers about cost-effective strategies for increasing physical activity, the committee said. Additional federal funds are needed to support multiyear studies to assess people's behavior over time as their environment changes, evaluations of how interventions that change the built environment affect physical activity levels, and additions to national travel and health databases. A collaborative effort to develop and fund an appropriate research agenda should be conducted by an interagency working group led by the U.S. Department of Health and Human Services and the U.S. Department of Transportation, the committee said.

National public health and travel surveys, such as the Behavioral Risk Factor Surveillance System and the National Household Travel Survey, should be expanded to provide more detailed information about where people exercise and travel, not only in their neighborhoods but also in their homes, at work, and at school, where people spend the majority of their time, the report says. These surveys should also consider various settings that may encourage or deter physical activity. For instance, the deteriorated physical condition of poor inner-city neighborhoods may discourage outdoor physical activity except for necessary trips. In other neighborhoods, people may feel encouraged to increase their daily physical activity by readily available facilities for recreational walking and cycling.

The study was sponsored by the Robert Wood Johnson Foundation and the Centers for Disease Control and Prevention. The Transportation Research Board is a division of the National Research Council, the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. The Research Council is a private, nonprofit institution that provides science and technology advice under a congressional charter. The Institute of Medicine is a private, nonprofit institution that provides health policy advice under a congressional charter granted to the National Academy of Sciences. A committee roster follows.