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Journal of Obesity
Volume 2014 (2014), Article ID 958645, 10 pages
Research Article

Trajectories of Objectively Measured Physical Activity among Secondary Students in Canada in the Context of a Province-Wide Physical Education Policy: A Longitudinal Analysis

1Public Health Ontario, 480 University Avenue, Suite 300, Toronto, ON, Canada M5G 1V2
2Manitoba Institute of Child Health, 513-715 McDermot Avenue, Winnipeg, MB, Canada R3E 3P4
3Propel Centre for Population Health Impact, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada N2L 3G1

Received 25 June 2013; Revised 17 September 2013; Accepted 5 October 2013; Published 20 January 2014

Academic Editor: George P. Nassis

Copyright © 2014 Erin Hobin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Lower levels of physical activity are associated with childhood obesity. School physical education (PE) policies have been identified as critical to improve child and adolescent physical activity levels but there has been little evaluation of such policies. In the province of Manitoba, Canada, the government implemented a mandatory PE policy in secondary schools designed to increase the daily physical activity levels of adolescents. The objective of this study was to examine the longitudinal changes in and the factors associated with the physical activity trajectories of adolescents in Manitoba during their tenure as secondary school students in the context of this school PE policy. The results found, despite the PE policy, a grade-related decline in the physical activity trajectories of adolescents; however, the decline in physical activity was attenuated among adolescents with low and moderate baseline physical activity compared to adolescents with high baseline physical activity and among adolescents who attended schools in neighbourhoods of low compared to high socioeconomic status. There are several possible explanations for these findings, including the influence of the PE policy on the PA patterns of adolescent subpopulations that tend to be at higher risk for inactivity in both childhood and adult life.