School of Kinesiology & Health Studies Graduate Theses

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    Changes in Body Composition in Relation to the Metabolic Syndrome: A Compositional Data Aanalysis in Adults with Overweight and Obesity
    Miller, Erin J.; Kinesiology and Health Studies; Ross, Robert
    Background: Current knowledge of the association between body composition and health outcomes is based on traditional regression techniques, where the components of body composition are treated as non-compositional independent variables. Mounting evidence suggests that body tissues are biologically co-dependent and therefore require a statistical technique that considers this. Compositional data analysis (CoDA) allows for the study of compositional co-dependent variables and is the optimal statistical technique for body composition research. Purpose: To use a CoDA framework to explore the longitudinal association between body composition and the metabolic syndrome (MetS). Methods: Participants included 288 (non-exercise control, n = 56; intervention, n = 232) physically inactive adults (age: 55.7±11.9 years [mean±SD]; 56.3% female) with overweight or obesity (BMI: 31.3±3.5 kg/m2) who participated in randomized controlled trials to determine the effects of exercise or caloric restriction on visceral adipose tissue (AT), abdominal and peripheral subcutaneous AT, other AT (e.g., intermuscular AT, pericardial AT), skeletal muscle and other lean tissues (e.g., organs, bone), assessed by whole-body magnetic resonance imaging. The outcome was a continuous MetS score. Associations were examined using CoDA. Results: Visceral AT, relative to the mass of the remaining tissues, was significantly associated with the MetS score pre- and post-intervention (P < 0.05). The slopes and intercepts of the pre- and post-intervention regression lines between relative visceral AT mass and MetS did not differ (P > 0.2). The relative contribution of the other tissues was not related to MetS pre- or post-intervention (P > 0.1). For a given weight loss, the greater the relative reduction in visceral AT, the larger the decrease in the CoDA predicted MetS score. Conclusion: These CoDA findings reinforce that visceral AT is an important marker of cardiometabolic risk and should be a primary target for therapeutic strategies in individuals with overweight or obesity.
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    The Politics of Choice: Women’s Experiences of Deciding to Be Childfree
    Luchenski, Jamie N.; Kinesiology and Health Studies; Adams, Mary Louise
    This study explores the experiences of childfree women and examines how they navigate the choice not to have children and how they understand their decision in relation to western societal norms and cultural expectations. I bring attention to how the personal decisions and experiences of childfree women are influenced by prevailing social norms. The purpose of this research was to explore the following questions: (1) How do women navigate and understand their choice to be childfree? (2) What do women believe an intentionally childfree life looks like? and (3) Do different women experience the pressures to have children differently? How? I conducted interviews with 13 intentionally childfree, heterosexual women between the ages of 20 and 40. I then used a feminist, intersectional theoretical lens to analyze the data. My findings indicated that gendered social expectations for women’s lives are upheld by various social structures that have an impact on women’s decisions to be childfree. While these expectations are placed on all women, there is variability in women’s experiences related to factors including, but not limited to, religious affiliation and racial or ethnic identity. I also found that childfree women desire community and benefit from spaces where they can be validated for their decision and learn more about the implications of being childfree. They also hope that open dialogue about the possibility of being childfree will normalize this decision for women. I found that while women recognize that their decision to be childfree places them outside of the social norm of what is typically expected of women, they rarely seem to challenge the social structures which limit their choices, turning instead to individual level solutions. I conclude that to grant women full access to the choice to be childfree, feminist social movements ought to focus on women’s liberation not only in terms of reproductive autonomy, but also by challenging the nuclear family and some of the broader structures that hold it in place, like neoliberal capitalism.
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    Associations between Sleep and Social-Emotional Development in Early Years Children
    Visser, Carson B.; Kinesiology and Health Studies; Janssen, Ian
    Background: The early years are a critical period of life for social-emotional health and poor social-emotional development could have negative downstream effects later in life. It is well known that sufficient sleep is important for healthy growth and development in young children. However, sleep has been studied as individual sleep characteristics in this age group, rather than as a collective that considers the multidimensionality of sleep. The aim of this study was to examine the relationship between individual sleep characteristics and sleep profiles and indicators of social-emotional health in early years children. Methods: 588 preschoolers (3-4.9 years old) and 202 early school-aged children (5-6.6 years old) participants from the Sleep and Activity Database for the Early Years (SADEY) were studied. Sleep characteristics (duration, quality, timing, consistency, and naps) were measured using actigraph GT3X+ accelerometers. Cluster analysis was used to create sleep profile clusters representing different types of sleepers. The Strengths and Difficulties Questionnaire (SDQ) was used to measure hyperactivity, emotional regulation, conduct problems, peer problems, prosocial behaviour, and a total SDQ score. General linear models were used to compare differences in SDQ scores between sleep profile clusters and to determine the association between individual sleep characteristics and SDQ scores. Results: Three sleep profile clusters were identified in preschool children and in early school- aged children. In preschoolers, Cluster 1 had a short nap duration, Cluster 2 had a short sleep duration and late sleep timing, and Cluster 3 had a long sleep duration and early sleep timing. Peer problem scores were significantly lower in Cluster 1 compared to Cluster 3 (p < .05). There was a positive linear relationship between nap duration and peer problems and a negative relationship between later sleep timing and prosocial behaviour (p < .05). In early school-aged children, Cluster 1 had a short sleep duration and nap duration, Cluster 2 had a long sleep duration and late sleep timing, and Cluster 3 had an early sleep timing. SDQ scores did not differ across these sleep clusters. There was a negative relationship between sleep duration and conduct problems (p < .05). All other group differences and associations for preschoolers and early school-aged children that are not reported here were non-significant (p > .05). Conclusion: Few associations existed between sleep and social-emotional health and development in this study of early years children.
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    The Efficacy of a Non-Exercise Estimated Cardiorespiratory Fitness Algorithm Without Physical Activity to Stratify Health Risk and Response to Treatment
    Abrego, Carlos G.; Kinesiology and Health Studies; Ross, Robert
    Non-exercise estimated cardiorespiratory fitness (eCRF) provides feasible estimates of CRF. The widespread use of electronic health records (EHRs) is rapidly emerging, allowing for the retrospective assessment of CRF. However, a majority of eCRF algorithms are derived using physical activity (PA) data, a main modifiable determinant of CRF that is not routinely documented in EHRs. For this reason, several eCRF algorithms have been derived without the inclusion of a PA data. However, these algorithms tend to lack accuracy due in part to being derived from relatively small samples. As a result, Sloan and colleagues derived an eCRF algorithm without a PA variable using a large sample and variables common to EHRs. Yet to be determined is whether eCRF derived using the Sloan algorithm can accurately: 1) predict mCRF 2) follow the exercise-induced change in mCRF. Six hundred and one adults with overweight or obesity participated in lifestyle-based, randomized control trials. Of these, 287 participants with complete pre- and post-intervention CRF values were included to determine the algorithm’s ability to follow exercise-induced change in mCRF determined using indirect calorimetry. No significant difference between eCRF and mCRF was observed at baseline. However, the observed error between eCRF and mCRF was large. Additionally, the estimates derived using the Sloan algorithm correctly classified 42 – 62% of participants into their respective mCRF quartiles. Change in eCRF was significantly different to the observed changes in mCRF, as the exercise-induced changes in mCRF were substantially greater than the change scores predicted by the Sloan algorithm. eCRF derived using the Sloan algorithm was not different from mCRF values. However, the observed error suggests that estimates derived using the Sloan algorithm lack the ability to accurately stratify CRF associated health risk on an individual basis. Estimates of CRF derived using the Sloan algorithm were not capable of predicting exercise-induced change in mCRF.
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    Co-producing tools to support integrated primary care discussions and medical curriculum renewal: A mixed methods dissertation to guide implementation of the 24-Hour Movement Guidelines for Adults
    Morgan, Tami L.; Kinesiology and Health Studies; Tomasone, Jennifer
    Calls for physical activity (PA) promotion in medical practice and education have long populated the literature. Some tools have been integrated into primary care and some content on PA prescription and counselling have graced the medical curriculum in aims of improving health professionals’ knowledge and frequency of, and confidence and skill in, PA promotion. Often, PA is the only movement behaviour emphasized in these initiatives; however, Canada’s 24-Hour Movement Guidelines for Adults (24HMG) now support the health benefits of achieving an optimal combination of three interrelated movement behaviours—PA, sedentary behaviour, and sleep. Further, many of these initiatives have not adequately considered the specific contexts of primary care providers (PCPs) and medical educators, resulting in the need for tools and strategies that better address these knowledge-practice gaps. Mobilizing 24HMG evidence in practice is dependent on individual and contextual factors. Thus, to enhance movement behaviour promotion in primary care and medical education, the barriers, enablers, and complexity inherent in these two contexts must be considered. The overarching objective of this mixed methods dissertation was to enhance the uptake and use of the 24HMG among health professionals in Canada. A co-production approach was taken in all five studies to collaborate with relevant primary care and medical education experts from project outset. The aim of Studies 1-3 was to co-develop a tool for PCPs to implement the 24HMG in their practice. A scoping review followed by a qualitative think-aloud and near-live study and a mixed methods modified Delphi study were conducted. Findings informed the co-development and dissemination of the Whole Day Matters Toolkit for Primary Care. The aim of Studies 4-5 was to co-develop a competency-based curriculum map and integrated mapping process to implement the 24HMG in the local medical curriculum. An environmental scan of the local medical curriculum was performed, followed by a mixed methods modified Delphi study. Findings led to a 24HMG curriculum map, 24HMG objectives, and considerations for engaging in integrated curriculum mapping processes in competency-based education. The results of this dissertation have far-reaching implications including guiding future movement behaviour promotion in medicine, discussion tool development, and competency-based curriculum renewal.