title: Are buffers around home representative of physical activity spaces among adults?
abstract: Residential buffers are frequently used to assess built environment characteristics relevant to physical activity (PA), yet little is known about how well they represent the spatial areas in which individuals undertake PA. We used System for Observing Play and Recreation in Communities data for 217 adults from five US states who wore an accelerometer and a GPS for three weeks to create newly defined PA-specific activity spaces. These PA spaces were based on PA occurring in bouts of ≥10min and were defined as 1) the single minimum convex polygon (MCP) containing all of a participant's PA bout minutes and 2) the combination of many MCPs constructed using each PA bout independently. Participants spent a large proportion of their PA bout time outside of 0.5, 1, and 5 mile residential buffers, and these residential buffers were a poor approximation of the spatial areas in which PA bouts occurred. The newly proposed GPS-based PA spaces can be used in future studies in place of the more general concept of activity space to better approximate built environments experienced during PA.
authors.affiliation: University of North Carolina at Chapel Hill, Department of Epidemiology, 137 East Franklin Street Suite 306, Chapel Hill, NC 27514, USA. Electronic address: khausman@email.unc.edu.
authors.forename: Katelyn M
authors.initials: KM
authors.lastname: Holliday
authors.affiliation: University of North Carolina at Chapel Hill, Department of Biostatistics, 137 East Franklin Street Room 6702, Chapel Hill, NC 27514, USA. Electronic address: aghoward@email.unc.edu.
authors.forename: Annie Green
authors.initials: AG
authors.lastname: Howard
authors.affiliation: University of North Carolina at Chapel Hill, Departments of Geography and Epidemiology, 206 Carolina Hall CB #3220, Chapel Hill, NC 27599, USA. Electronic address: emch@email.unc.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Emch
authors.affiliation: University of California, Berkeley, Department of City and Regional Planning, 313B Wurster Hall #1820, Berkeley, CA 94720, USA. Electronic address: danrod@berkeley.edu.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Rodríguez
authors.affiliation: University of North Carolina at Chapel Hill, Department of Epidemiology, 137 East Franklin Street Suite 306, Chapel Hill, NC 27514, USA. Electronic address: kelly_evenson@unc.edu.
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Evenson
mesh_terms: D061725:Accelerometry / Q000379:methods; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015444:Exercise / Q000502:physiology*; D005260:Female; D040362:Geographic Information Systems / Q000295:instrumentation; D006798:Housing; D006801:Humans; D008297:Male; D008875:Middle Aged; D011998:Recreation / Q000502:physiology*
keywords: Accelerometry; Activity space; Global positioning systems; Physical activity; Residential buffers