|dc.description.abstract||The increasing prevalence of high sedentary behaviour and low physical activity has paved the way for upstream population health policy interventions that focus on modifying built environment to facilitate a population-wide decrease in sedentary behaviour and increase in physical activity. As a result of this, an inter-disciplinary field of study is gaining prominence to understand the influence of built environment on sedentary behaviour and physical activity ─ Active living research. Even though there is a growing body of evidence that indicates the influence of built environment on physical activity; active living research is still considered an emerging field due to critical gaps in its conceptualization and implementation.
The purpose of this three study dissertation is to address some of these key gaps and lay the foundation for more rigorous active living research. With this dissertation being a quantitative component of an active living research initiative in Saskatoon, Saskatchewan, Canada, called Smart Cities Healthy Kids (www.smartcitieshealthykids.com), the primary gap addressed is the dearth of active living research among children. Moreover, the three independent studies that compose this dissertation build upon each other’s evidence by developing evidence-based methods to address measurement and evaluation of active living evidence.
Although, physical activity and sedentary behaviour are increasingly measured with objective devices such as accelerometers, there still exists a possibility of inducing measurement bias due to the disproportionate amount of time these devices are worn (wear-time) by participants. This study specifically explores wear-time variation, both within and between participants, and thereafter, examines the influence of systematic wear-time variation on the accumulation of physical activity and sedentary behaviour.
In doing so, this study proposes a data standardization methodology to minimize measurement bias due accelerometer wear-time variation.
Increasingly, research indicates that sedentary behaviour is independently associated with a wide range of health outcomes; however, thus far, active living research has predominantly focused on only physical activity. Moreover, even though physical activity and sedentary behaviour are two distinct behaviours, their inter-dependent relationship needs to be studied in the same environment.
This study examines the influence of urban design, neighbourhood built and social environment, and household and individual factors (i.e., diverse environmental exposures) on objectively measured physical activity and sedentary behaviour in children aged 10-14 years. In doing this, this study combines its evidence with the World Health Organization physical activity guidelines to develop age-specific activity profiles. Generation of activity profiles enables a holistic picture of the influence of environment on the interplay between two distinct, yet related behaviours ─ physical activity and sedentary behaviour. The ultimate purpose of these activity profiles is to advance a consistent method to evaluate and compare active living evidence.
To date, active living research has predominantly been conducted without taking variation in weather into account. Moreover, emerging evidence indicates that studying the influence of environment on physical activity and sedentary behaviour without considering weather variation, especially in the Canadian context, could generate results of low validity. Thus, this study aims to understand the influence of variation in weather on objectively measured physical activity and sedentary behaviour in children aged 10-14 years. More importantly, as weather is non-modifiable, the greater focus of this study is to understand how diverse environmental exposures, including urban design, moderate the influence of weather on physical activity and sedentary behaviour during the transition from spring to summer in Saskatoon, Saskatchewan, Canada.
The three studies in the dissertation sequentially address key gaps in active living research. Study one proposes a methodology to minimize measurement bias and improve the analysis rigour of objective physical activity and sedentary behaviour data. Study two, taking diverse environmental exposures into consideration, investigates the inter-dependent nature of physical activity and sedentary behaviour, and proposes age-specific activity profiles that can be used to evaluate and compare active living evidence. Finally, study three reiterates the need to include weather variation in active living research by examining how environmental exposures moderate the influence of weather variation on physical activity and sedentary behaviour.
The factor that encompasses all three studies is the age group of the participants ─ 10 to 14 years. This age group reflects the transition from preadolescence to adolescence. Evidence indicates that physical activity and sedentary behaviour levels during adolescence track into adulthood, hence this dissertation aims to generate evidence that would advance active living interventions in this vital demographic. Specific to Saskatoon, preliminary evidence of this dissertation has aided the conceptualization of a Canadian Institutes of Health Research funded longitudinal study that will examine the influence of built environment on physical activity and sedentary behaviour in children aged 10-14 years in all four seasons of Saskatoon. Ultimately, in-depth evidence of this dissertation will also inform the implementation and analysis of the longitudinal study.||