Background and Objectives
Sedentary activity patterns in the U.S. are a contributing factor to hundreds of thousands of deaths every year. By limiting the opportunities for being physically active in every day life, contemporary urban areas are believed to play a role in encouraging these sedentary activity patterns. As a result, researchers and policy makers are examining the characteristics of the built and natural environments that can be supportive of active living.
Specific Aims
a) Replicate and test the statistical and practical significance of the relationship between objectivelymeasured physical activity and an expanded range of measures of the built and natural environments;
b) Examine potential substitution effects among the locations where physical activity can take place by collecting original data on how people allocate time to physical activity and details on where such activity occurs; and
c) Incorporate individual preferences and attitudes to examine issues of self-selection related to location and physical activity levels.
Methods and Study Area
We are using a quasi-experimental research design based on a microeconomic behavioral model to examine the simultaneous influence of factors related to the physical environment on time allocated to physical activity at various locations (at home, in one's local neighborhood, for travel, or at other locations). We rely on a socio-ecologic model to identify individual factors, social factors, social-environmental factors, attitudinal/habitual factors, and physical environmental factors at the individual level that can influence the relationship modeled.
The study takes place in Montgomery County, Maryland. We use a two-stage clustered sampling research design to identify participants. Residents of five neighborhoods in Bethesda, Forest Glen, Four Corners, Layhill and Olney will be invited to participate in the study. These neighborhoods represent the continuum between exurban and urban built environments in Montgomery County. Primary and secondary data sources are being used to develop a broad number of objective measures of the built environment, which will be combined with objective and self-reported data on physical activity. Participants will be equipped with an accelerometer in order to objectively measure physical activity. Participants will use a location diary to collect information on physical activity and where it occurs and fill-out an in-person, computer assisted survey. Survey data will be combined with detailed GIS data and with direct field observations to develop measures of the built environment classified as land use intensity, land use mix, street connectivity, urban infrastructure, micro-design attributes, and regional access measures.
The proposed approach combines new objective measurements, rich secondary data, and the application of a rigorous behavioral framework to study individual physical activity behavior. This combination of the socioecologic model for identifying relevant variables, and an economic model for examining their relationship with physical activity constitutes a prime example of the type of transdisciplinary research necessary to improve our understanding of the determinants of physical activity.
