Meaghan Nolan, J. Ross Mitchell and Patricia K. Doyle-Baker
The popularity of smartphones has led researchers to ask if they can replace traditional tools for assessing free-living physical activity. Our purpose was to establish proof-of-concept that a smartphone could record acceleration during physical activity, and those data could be modeled to predict activity type (walking or running), speed (km·h−1), and energy expenditure (METs).
An application to record and e-mail accelerations was developed for the Apple iPhone®/iPod Touch®. Twentyfive healthy adults performed treadmill walking (4.0 km·h−1 to 7.2 km·h−1) and running (8.1 km·h−1 to 11.3 km·h−1) wearing the device. Criterion energy expenditure measurements were collected via metabolic cart.
Activity type was classified with 99% accuracy. Speed was predicted with a bias of 0.02 km·h−1 (SEE: 0.57 km·h−1) for walking, –0.03 km·h−1 (SEE: 1.02 km·h−1) for running. Energy expenditure was predicted with a bias of 0.35 METs (SEE: 0.75 METs) for walking, –0.43 METs (SEE: 1.24 METs) for running.
Our results suggest that an iPhone/iPod Touch can predict aspects of locomotion with accuracy similar to other accelerometer-based tools. Future studies may leverage this and the additional features of smartphones to improve data collection and compliance.
Gavin R. McCormack, Christine M. Friedenreich, Billie Giles-Corti, Patricia K. Doyle-Baker and Alan Shiell
The built and social environments may contribute to physical activity motivations and behavior. We examined the extent to which the Theory of Planned Behavior (TPB) mediated the association between neighborhood walkability and walking.
Two random cross-sectional samples (n = 4422 adults) completed telephone interviews capturing walking-related TPB variables (perceived behavioral control (PBC), attitudes, subjective norm, intention). Of those, 2006 completed a self-administered questionnaire capturing walkability, social support (friends, family, dog ownership), and neighborhood-based transportation (NTW) and recreational walking (NRW). The likelihood of undertaking 1) any vs. none and 2) sufficient vs. insufficient levels (≥150 vs. <150 minutes/week) of NTW and NWR, in relation to walkability, social support, and TPB was estimated.
Any and sufficient NTW were associated with access to services, connectivity, residential density, not owning a dog (any NTW only), and friend and family support. Any and sufficient NRW were associated with neighborhood aesthetics (any NRW only), dog ownership, and friend and family support. PBC partially mediated the association between access to services and NTW (any and sufficient), while experiential attitudes partially mediated the association between neighborhood aesthetics and any NRW.
Interventions that increase positive perceptions of the built environment may motivate adults to undertake more walking.
Gavin R. McCormack, Alan Shiell, Patricia K. Doyle-Baker, Christine Friedenreich, Bev Sandalack and Billie Giles-Corti
Capturing neighborhood-specific physical activity is necessary to advance understanding of the relations between neighborhood walkability and physical activity. This study examined the test–retest reliability of previously developed items (from the Neighborhood Physical Activity Questionnaire) for capturing setting-specific physical activity among Canadian adults.
Randomly sampled adults (N = 117) participated in 2 telephone interviews 2 to 5 days apart. Respondents were asked a series of items capturing frequency and duration of transportation-related walking, recreational walking, and moderate- and vigorous-intensity physical activity undertaken inside and outside the neighborhood in a usual week. The test–test reliability of reported physical activity levels were then examined using intraclass and Spearman’s rank correlations, kappa coefficients, and overall agreement.
Participation, frequency, and the duration of transportation-related and recreational walking and vigorous-intensity physical activity inside and outside the neighborhood showed moderate to excellent test–retest reliability. Moderate reliability was found for moderate-intensity physical activity undertaken inside (k = .48; ICC frequency = .38; ICC duration = .39) and outside (k = .51; ICC frequency = .79; ICC duration = .31) the neighborhood.
Neighborhood-specific physical activity items administered by telephone interview are reliable and are therefore appropriate for use in future studies examining neighborhood walk-ability and physical activity.
Gavin R. McCormack, John C. Spence, Tanya Berry and Patricia K. Doyle-Baker
Research regarding the pathways via which the environment influences physical activity is limited. This study examined the role of perceived behavioral control (PBC) in mediating the relationship between perceptions of neighborhood walkability and frequency of moderate (MODPA) and vigorous physical activity (VIGPA).
Data were collected through a province-wide survey of physical activity. Telephone-interviews were conducted with 1207 adults and captured information about perceptions of neighborhood walkability, physical activity, PBC and demographics. Gender-stratified regression analyses were conducted to test PBC mediation of the built environment-physical activity association.
Among women easy access to places for physical activity was positively associated with MODPA and VIGPA. Having many shops and places within walking distance of homes was also positively associated with MODPA among women however; reporting sidewalks on most neighborhood streets, and crime rate in the neighborhood were negatively correlated with MODPA. Among men, easy access to places for physical activity was positively associated and crime rate in the neighborhood negatively associated, with VIGPA. After adjusting for PBC, the association between easy access to places for physical activity and VIGPA and MODPA attenuated for men and women suggesting mediation of this association by PBC.
PBC mediated the relationship between easy access to places for physical activity and physical activity, but not for other perceived environmental attributes.