Bumjoon Kang, assistant professor of urban and regional planning, and collaborators assess the associations between a change in time spent walking and a change in total physical activity (PA) time within an urban living adult sample, to test for additive or substitution effects.
Participants living in the greater Seattle area were assessed in 2008–2009 and again 1–2 years later (2010–2011). At each time point, they wore accelerometers and GPS units and recorded trips and locations in a travel diary for 7 consecutive days. These data streams were combined to derive a more objective estimate of walking and total PA. Participants also completed the International Physical Activity Questionnaire to provide self-reported estimates of walking and total PA. Regression analyses assessed the associations between within-participant changes in objective and self-reported walking and total PA.
Data came from 437 participants. On average, a 1-minute increase in total walking was associated with an increase in total PA of 1 minute, measured by objective data and 1.2-minute, by self-reported data. A similar additive effect was consistently found with utilitarian, transportation, or job-related walking, measured by both objective and self-reported data. For recreational walking, the effect of change was mixed between objective and self-reported results.
Both objective and self-reported data confirmed an additive effect of utilitarian and total walking on PA.
Bumjoon Kang, Assistant Professor
Department of Urban and Regional Planning
Anne V. Moudon
Philip M. Hurvitz
Urban Form Lab and the Department of Urban Design and Planning, University of Washington, Seattle
Brian E. Saelens
Seattle Children’s Research Institute and Department of Pediatrics, University of Washington, Seattle
Medicine & Science in Sports & Exercise