School of Kinesiology & Health Studies Graduate Theses

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    Influence of Acute Beetroot Juice Supplementation During High Intensity Fatiguing Forearm Exercise in Healthy Recreationally Active Males
    (2024-05-17) Fenuta, Alyssa Marie; Kinesiology and Health Studies; Tschakovsky , Michael
    Introduction: Exercise performance/tolerance improves with increasing oxygen delivery relative to consumption. Evidence suggests elevating blood nitrite levels may increase vasodilation and thereby oxygen delivery, and reduce the oxygen cost of exercise, improving exercise performance/tolerance. Purpose: To determine if: 1) peak oxygen delivery:consumption is achieved during maximal effort forearm exercise identifying critical impulse, and 2) acute nitrate supplementation increases blood plasma [nitrite] improving oxygen delivery relative to consumption thereby increasing high intensity exercise performance (i.e. critical impulse, incremental exercise limit of tolerance). Methods: Thirteen healthy males performed two fatiguing forearm handgrip exercise protocols (i.e. 10-minutes maximal effort vs. incremental exercise to limit of tolerance) while laying supine with arms outstretched 90⁰, with vs. without beetroot juice consumed 2.5 hours pre-exercise. Arterial oxygen saturation (pulse oximeter), arterial blood pressure (finger photoplethysmography), and exercising forearm blood flow (echo and Doppler ultrasound) were measured. Deep vein blood sampling assessed exercising forearm muscle metabolism and nitrate to nitrite conversion. Results: 1) Peak forearm oxygen delivery did not differ between the two handgrip protocols. Despite achieving a lower impulse at the end of the maximal effort protocol identifying critical impulse compared to incremental exercise, the former resulted in a higher peak oxygen consumption via increased extraction indicating increased oxygen cost. 2) Acute beetroot juice supplementation resulted in repeatable increases in blood plasma [nitrite], however did not influence forearm blood flow (vasodilatory or pressor response), oxygen delivery, oxygen consumption or exercise performance/tolerance in either protocol. Beetroot juice supplementation a) reduced the oxygen cost for a given contraction impulse magnitude in the transition to critical impulse, and b) increased oxygen extraction at submaximal exercise intensities during incremental exercise. Conclusions: Maximal effort exercise identifying critical impulse results in peak oxygen delivery:consumption and may better assess forearm aerobic capacity compared to an incremental exercise protocol. Contrary to animal work, our findings do not support the influence of beetroot juice supplementation on human muscle blood flow across the entire forearm exercise intensity continuum or handgrip exercise performance/tolerance. Additional investigation is required to explore the specific mechanism(s) potentially influencing microvascular distribution and muscle economy differences with beetroot juice supplementation.
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    An interpretative phenomenological analysis of parent-child co-participation in mountain biking
    (2024-05-14) Smith, Haley Hunter; Kinesiology and Health Studies; Côté, Jean
    Parent-child relationships are known to be particularly influential on youth sport outcomes (e.g., Dorsch et al., 2021). The sport environment is intimately related to the social dynamics experienced in youth sport, influencing what types of parent-child interactions may occur (e.g., Côté et al., 2020). Non-traditional sports provide contexts for one unique type of influential relationship interaction; parent-child co-participation (e.g., Nash & Moore, 2021). Little research has been conducted on this phenomenon to date, but the existing literature shows that co-participation holds potential to greatly impact youth, adult, and adult-youth relationship outcomes (Smith & Côté, 2023). Therefore, the present study aimed to examine experiences of parent-child co-participation, with the intent to understand the processes and outcomes of these interactions. Using an interpretative phenomenological study design, semi-structured individual interviews were conducted with seven parent-child dyads. The data were then analyzed according to the IPA tradition (Larkin & Flowers, 2018). Four themes were constructed through this analysis: (a) Family-based and independent participation are two complementary pathways to co-participation; (b) Parents flow between the roles of peer, partner, and provider; (c) Participants employ adaptive strategies on either side of the ‘sweet spot’ of skill overlap; and (d) Shared activity allows for positive interpersonal interactions and relationship building. When present in concert in a regular and recurring manner, these four themes create fulfilling co- participation experiences between parents and their children. These results demonstrate co- participation’s potential to act on the short, mid, and long-term outcomes of sport participation for both youth and adults, as well as on parent-child relationship development. Theoretically, these findings contribute to the field’s understanding of support and optimal parent involvement. Practically, these findings provide insights in response to questions put forth by Cycling Canada and represent potential strategies sport organizations may employ to improve parent engagement and behaviours.
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    Investigating Impacts of Twenty-Four-Hour Movement Behaviours on Healthy Ageing in Older Adults
    (2024-05-14) Hakimi, Shawn; Kinesiology and Health Studies; Rosenberg, Mark; Martin , Luc
    The impacts of 24-hour movement behaviours [a term that collectively refers to physical activity (PA), sedentary behaviour (SB), and sleep] on healthy ageing in older adults is understudied. Of this limited literature, the extent of associations between movement behaviours and healthy ageing outcomes are largely hampered by flawed methodological approaches for analysing movement behaviour data. My aim with this thesis research is to use an integrated approach to more closely examine associations between daily movement behaviours and two key determinants of healthy ageing: quality of life (QOL) and depression symptoms. The objectives are to: 1) synthesise and critically examine the literature on movement behaviours and QOL; 2) employ compositional data analysis to examine associations between movement behaviours and QOL and depression symptoms, respectively to determine if associations still hold, and how effects of changing time spent between movement behaviours impact these two outcomes relative to the time spent in remaining behaviours, focussing exclusively on the Canadian older adult population ≥ 65 years of age. Manuscript one is the first to systematically review the literature on movement behaviours and QOL in older adults using an integrated movement behaviour approach. It is also the first to represent QOL by distinct domains, and to categorise and group study results accordingly. Overall, the findings indicate that movement behaviours are associated with QOL. Moderate-to-vigorous physical activity (MVPA) is favourably associated with QOL. The evidence regarding light-intensity physical activity (LIPA), SB and sleep duration is inconsistent. Subsequently, two empirical studies applied a compositional data analysis framework to data from the Canadian Longitudinal Study on Aging. Results from both analyses show that older Canadians spend most of their time across the day in SB and sleep, with limited activity and that daily movement behaviour composition is strongly associated with QOL and depression symptoms, respectively. In manuscript two, results show how reduction in time spent sedentary and increases in PA and sleep improve QOL. In manuscript three, results show how replacing time in MVPA with equivalent time from any other behaviour is associated with increase in depression symptoms. In both manuscripts, stratified analyses indicate that effects differ by sex and age group (younger old versus older old). Collectively, the findings from this thesis research demonstrate that the way older adults spend their time in movement behaviours throughout the course of a day has implications for healthy ageing. The work provides new avenues for researchers to explore how 24-hour movement behaviours are related to older adult health.
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    Evaluating the Integration of Physical Activity Content for People with Disabilities into an mHealth Format
    (2024-04-30) Reissner, Brock Michael; Kinesiology and Health Studies; Latimer-Cheung, Amy
    mHealth apps offer one way for people with disabilities to self-manage their physical activity behaviour and to achieve and maintain well-being. However, the design and content of physical activity apps do not meet the accessibility and inclusion needs of diverse user groups. For example, the ParticipACTION app, a physical activity app made by the Canadian non-profit organization to encourage Canadians to move more, is not inclusive. To address this shortcoming and to model a practical approach to knowledge translation, we developed and implemented a process for creating evidence-based, disability-specific content for the ParticipACTION app. Thirty pieces of evidence-based, inclusive content were created and integrated into the ParticipACTION app. Using the RE-AIM framework as a guide, this thesis explores and evaluates the integration of mHealth physical activity content designed for people with disabilities into the ParticipACTION app. The RE-AIM framework was operationalized to include indicators for (1) Reach, which was measured by the proportion of app users that have a disability; (2) Effectiveness, which was measured by the total number of inclusive content consumed by people with disabilities; (3) Adoption; which was measured by the number of inclusive articles that were integrated into the ParticipACTION app; (4) Implementation; which was measured by calculating the percentage of ParticpACTION’s yearly budget that is now dedicated to inclusive content development and; (5) Maintenance; which was measured by calculating the number of ParticipACTION staff identified to maintain this work overtime. Data sources included in-app surveys and challenges available in the ParticipACTION app. Connection to fitness trackers allows for physical activity behaviour to be tracked in the app. Descriptive analyses revealed that reach is low, with only 3.2% of new app users having a disability. Although the ParticipACTION app now has content relevant to people with disabilities, few users are engaging with the content. The findings emphasize the importance of utilizing a knowledge translation approach to implement disability-specific physical activity content into an mHealth format. This work presents considerations for researchers and health promoters aiming to develop appropriate mHealth intervention integration and evaluation techniques for adults living in Canada, and more specifically, those with disabilities.
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    The Effects of Diets on Vulnerability to Oscillatory Shear Stress-Induced Endothelial Dysfunction
    (2024-04-09) Etwaroo, Raelisa; Kinesiology and Health Studies; Pyke, Kyra
    Endothelial cells line the walls of the arteries, and the proper function of these cells is essential for maintaining arterial health. Endothelial cells allow the widening of blood vessels (vasodilation) in response to blood flow-associated shear stress (frictional force of blood on artery wall) in a response called flow-mediated dilation (FMD). Oscillatory shear stress (OSS), characterized by low mean shear and retrograde shear stress, occurs in regions of the artery that are curved and branched and results in endothelial dysfunction and increased risk of plaque formation due to increased levels of highly reactive molecules (oxidative stress). No study has explored the impact of chronic dietary antioxidant intake on OSS-induced endothelial dysfunction. The purpose of the study reported in Chapter 3 was to investigate whether high dietary intake of antioxidants confers protection from transient OSS exposure-induced endothelial dysfunction. We hypothesized that diets high in antioxidants indicated by high vitamin C and E intake and a high frequency of fruit and vegetable consumption would be associated with a smaller decline in FMD following transient OSS exposure. Fifteen healthy males (22± 3 years [Mean ± SD]) participated in an experimental visit in which brachial artery FMD was assessed with ultrasound before and after 30 min of OSS exposure induced with mild forearm cuff occlusion. Dietary antioxidant content was estimated from the food tracking app Keenoa (vitamin C and E intake over three days) and frequency of fruit and vegetable intake via a food frequency questionnaire. OSS exposure resulted in a significant decline in FMD (pre 9.9% ± 3.5% vs. post 7.2% ± 3.6% p=<0.001). No relationship was found between the magnitude of post-OSS FMD impairment and either antioxidant vitamin intake (r2= 0.01; p= 0.723) or frequency of fruit and vegetable consumption (r2 = 0.005; p=0.809). These preliminary findings suggest that higher dietary antioxidant intake may not be associated with protection from OSS-induced endothelial dysfunction in healthy young men. However, further research in additional populations with more precise quantification of antioxidant intake and blood levels of antioxidants and estimates of oxidative stress is required to make a more definitive conclusion.