%0 Journal Article
%T Trajectories of Objectively Measured Physical Activity among Secondary Students in Canada in the Context of a Province-Wide Physical Education Policy: A Longitudinal Analysis
%A Erin Hobin
%A Jannice So
%A Laura Rosella
%A Melisa Comte
%A Steve Manske
%A Jonathan McGavock
%J Journal of Obesity
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/958645
%X 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. 1. Introduction The prevalence of overweight and obesity has risen dramatically among Canadian youth. Since 1981, childhood obesity rates have almost tripled, with approximately 31.5% of Canadians aged 5¨C17 years currently being overweight or obese [1]. Childhood obesity is an important predictor of adult obesity and significantly increases the risk of chronic disease, including type 2 diabetes and cardiovascular disease [2, 3]. Increasing physical activity (PA) to levels recommended by experts can contribute to lowering the risk for overweight and obesity among children and adolescents [4]. Despite the protective link between PA and obesity, recent surveillance studies suggest that up to 93% of Canadians aged 6¨C19 years do not achieve the recommended dose of PA required for adequate growth and health [5]. Furthermore, the rates of inactive youth increase rapidly in the years following puberty and reach a pinnacle in adolescence where PA rates can decline by as much as 85% by the age of 15 years [6, 7]. The rates of obesity are also highest during this period of development (15¨C18 years) [8]. As physical inactivity in adolescence predicts PA patterns in adulthood and physical inactivity is associated with a cost of $4 billion to the Canadian
%U http://www.hindawi.com/journals/jobe/2014/958645/