Kinesiology & Health Science

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Open Access
The Effects of Nutrient Availability and O-GlcNAcylation on Pericyte Differentiation Fate
(2023-03-28) Azimikhiabani, Barbod; Haas, Tara
Pericytes are mural cells on the surface of capillaries, which may have the capacity to differentiate into various lineages. However, the factors that could determine their differentiation fate remain to be determined. I hypothesized that nutrient availability, O-GlcNAcylation status, and metabolic stress could alter pericyte phenotype. In my experiments, I used mesenchymal cells from the skeletal muscle of C57B16/J mice as a model, due to the similarity in the characteristics of mesenchymal cells and pericytes. My data showed that Zfp423 protein levels are higher when exposed to normal glucose levels (5 mM), compared to high glucose levels (25 mM), which leads to higher fat droplet formation in mesenchymal cells. However, my data did not support the influence of O-GlcNAcylation on adipogenesis. Lastly, I observed that Transforming growth factor-β1 could potentially induce myocyte-looking cell formation. This finding provides an insight into how nutrient availability could influence the differentiation potential of pericytes.
Open Access
Descriptive Analysis of Preseason Baseline Data Collected from University Varsity Student-Athletes Using a Comprehensive Assessment Battery
(2023-03-28) Migotto, Benjamin Daniel James; Hynes, Loriann M.
The objectives of this study were to conduct a descriptive analysis of preseason baseline data collected from university varsity student-athletes using a comprehensive battery of assessments and to examine the effects of sex, concussion history and their interaction on variables. 325 student-athletes (165 males; 160 females) completed one or more of the following assessments: Sport Concussion Assessment Tool-5 (SCAT5); force plate postural sway; Doppler ultrasound cerebral blood flow; Brain Dynamic IndicatorTM (BrDITM); HurtSHynesTM Test; oculomotor performance; Stroop Colour and Word Test. 140 student-athletes reported a history of concussion (RHOC) and 185 student-athletes had No RHOC. Significant effects of sex were observed for multiple variables within five assessments. A significant effect of concussion history was rarely observed. Significant interaction effects were found for variables in the BrDITM and HurtSHynesTM Test. Considerable ceiling effects in scoring were observed across all student-athletes for the SCAT5 five-word immediate memory test. Overall, this study expands our understanding of the variability of results for varsity student-athletes across a variety of baseline assessments. Furthermore, the results support the need to develop sex-specific models of recovery following sports-related concussion.
Open Access
Does Epigenetic Silencing Affect Skeletal Muscle Angiogenesis?
(2023-03-28) Akhtar, Sokaina; Roudier, Emilie
The skeletal muscle is a highly plastic tissue that is able to adapt to changes from different stressors such as exercise. Angiogenesis is the formation of new capillaries from existing vessels; allowing for better blood flow to the working skeletal muscles. Epigenetic modifications support changes in gene expression to allow for skeletal muscle adaptations. How histone silencing marks regulate skeletal muscle adaptations through angiogenesis in response to training is yet to be explored in depth. My thesis aims to research how histone silencing marks regulate skeletal muscle angiogenesis through MDM2 and EZH2, in the context of exercise. In C57BL6 female mice, 9 weeks of endurance training increased H3K27me3 protein global abundance. With an acute bout of exercise in 14 days trained, H3K27me3 decreased. Angiogenic gene Kdr mRNA expression decreased after 9 weeks of endurance training. Overall, exercise protocols affect the histone modifications and histone modifiers in the skeletal muscle.
Open Access
The Role of TFEB and TFE3 in Mediating Mitochondrial and Lysosomal Adaptations in Skeletal Muscle
(2023-03-28) Oliveira, Ashley Nicole Estima; Hood, David A.
Skeletal muscle adapts to external stimuli to meet metabolic and energetic needs imposed on it. As a highly metabolic tissue, mitochondria are the energetic cores of the cell and are central to the adaptive nature of muscle. Essential to the maintenance of mitochondria is the process of mitophagy, a selective form of autophagy through which damaged mitochondria are removed and degraded via the lysosome. Lysosomes and autophagy machinery are regulated by transcription factors, TFEB and TFE3, that are responsive to cellular stresses including exercise, disuse and starvation. Our work aimed to address the role of TFEB and TFE3 in mediating the adaptability of mitochondria in response to exercise and disuse. To understand the role of TFEB and TFE3 in mediating the effects of exercise, we employed an in vitro model and silenced the expression of TFEB and TFE3. While the absence of TFEB or TFE3 alone impacted the mitophagic response to a single bout of contractile activity, mitochondrial and lysosomal function improved with repeated bouts. These data support the notion that exercise stimulates multifaceted and often redundant signaling pathways to promote adaptations. However, the absence of TFEB and TFE3 together abolished functional mitochondrial and lysosomal adaptations to contractile activity, indicating that both TFEB and TFE3 together are required for adaptations. We also sought to evaluate the role of TFE3 in atrophic conditions using denervation of the sciatic nerve as a model of disuse in both males and females. Basally, females exhibited increased lysosomal content, higher mitophagy flux and improved mitochondrial function. In response to denervation however, females appeared to preferentially preserve mitochondrial content at the expense of function by reducing mitophagy flux. Curiously, the absence of TFE3 in vivo preserved muscle mass in males and mitochondrial content in both sexes following denervation but this in turn increased mitochondrial dysfunction similar to wildtype females. The significance of this work is that we provide further evidence of how lysosomes and mitochondrial turnover mediate mitochondrial adaptations to both positive and negative stimuli. Our data also highlight the importance of investigating the effect of biological sex, revealing distinct mitochondrial and lysosomal phenotypes in males and females.
Open Access
Regulation of Skeletal Muscle Mitochondrial, Quality Control by the Transcription Factors P53 and ATF4
(2023-03-28) Memme, Jonathan Matthew; Hood, David A.
Well-appreciated for its role in locomotion and posture, the metabolic profile of muscle has extended implications for mobility, along with the onset of disease. It is well-documented that endurance exercise promotes enhanced aerobic capacity, while prolonged disuse results in a diminished respiratory function, accompanied by fiber atrophy and weakness. A unique, and natural, feature of aging is the progressive loss of muscle mass, which develops from molecular changes within muscle that include diminished aerobic capacity and muscle strength. Thus, understanding the molecular mechanisms that promote muscle health or contribute to muscle decline are of considerable importance to identify therapeutic strategies that can preserve muscle function. Mitochondria are the culpable organelles in the maintenance of skeletal muscle metabolic health, and are therefore important regulators of a variety of factors contributing to muscle dysfunction, such as oxidative stress and antioxidants, apoptosis, inflammation, and Ca2+ handling, in addition to their role as the energy hubs of the cell. Mitochondrial quality control (MQC) involves multiple processes that coordinately regulate organellar biogenesis, turnover, and proteostasis (mitochondrial unfolded protein response) to maintain an optimal mitochondrial pool. While recent research has elucidated the importance of this synchronized control, science has yet characterized a single regulator of broad MQC pathways. The transcription factors p53 and ATF4 are two candidates that, in muscle, respond to various stressors, and are positioned at the nexus of these processes. Therefore, we explored the necessity of p53 and ATF4 in mediating mitochondrial adaptations. p53 muscle-specific knockout mice (mKO) had dysregulated signaling for MQC following 1-day of denervation- induced disuse, with further decrements in organelle function and MQC regulation after 7 days, especially with respect to the autophagy-lysosome system. Additionally, through ATF4 overexpression (OE) and knockdown (KD) in C2C12 myotubes, we found ATF4 to be an import mediator of MQC pathways, contributing to an enhanced mitochondrial network with augmented function, following C2C12 myotube differentiation, as well as acute and chronic contractile activity. Our data identify both p53 and ATF4 as two transcriptional regulators that each exhibit multifaceted control of mitochondrial health in muscle during both the pro- and mal-adaptive stimuli of exercise and disuse.
Open Access
Job-Related Aerobic and Musculoskeletal Fitness Standards for Front-Line Structural Firefighters That Qualify as bona fide Occupational Requirements; Critical Considerations
(2023-03-28) Hancock, Ryan Stephen; Jamnik, Veronica
Maximal oxygen consumption (VO2max) reflects the upper limit of the body’s aerobic fitness and represents the highest rate at which oxygen can be taken up, transported, and utilized by the body. It is the most widely used measure characterizing the effective integration of the body’s many physiological systems in exercise sciences. However, the precise measurement administration protocol and relevance of VO2max regarding physically demanding public safety occupations remain unclear. Structural firefighter applicants routinely have their VO2max measured to ensure that they possess the aerobic fitness required to perform the most frequently occurring and physically demanding on-the-job tasks safely and efficiently. The purpose of this research project was to determine 1) if using a verification phase (VP), following a graded exercise test (GXT), helped to accurately measure VO2max and affected the proportion of participants who met the job-related aerobic fitness standard, 2) if there were any significant relationships between the firefighter applicants’ VO2max, select physical characteristics and simulated job task completion times and performance scores, and 3) what effect short-term reduced-training (i.e., detraining), consequent to the COVID-19 pandemic restrictions, had on the job-related aerobic fitness and critical simulated job task completion times of firefighter applicants. Performing a VP helped to accurately measure VO2max and significantly increased the proportion of participants who met the job-related aerobic fitness standard. A VP should always be used to ensure the measurement of a VO2max and not just a VO2peak. Participants’ VO2max and select physical characteristics had significant negative regression weights on all simulated job task completion times. Multiple regression equations can predict simulated job task completion times and allow applicants to customize their physical activity and exercise regimes to ensure that they have the physical and physiological characteristics to successfully meet the job-related aerobic fitness and simulated job task standards. Short-term periods of reduced training significantly decreased the participants’ ability to meet the job-related aerobic fitness standard. Structural firefighters must engage in habitual exercise regimes to ensure they possess the aerobic and musculoskeletal fitness required to perform critical on-the-job tasks safely and efficiently during emergencies where job completion is critical to safety, life, and property.
Open Access
Sex Differences in Physiological Responses after Cardiac Rehabilitation
(2023-03-28) Bouakkar, Jenan; Edgell, Heather
Background and Purpose: Heart disease (HD) is one of the leading causes of death in men and women in Canada. Many HD patients are referred for cardiac rehabilitation (CR) which is a multidisciplinary outpatient supervised exercise program consisting of aerobic and resistance training to improve cardiovascular health. Previous studies have shown that healthy men and women respond differently to aerobic and resistance training. The purpose of this systematic review is to discover any physiological differences in male and female HD patient responses to a CR program. Methods and Results: A search strategy was generated to investigate at the relationships between heart disease patients, a supervised exercise program, physiological outcomes, and gender differences. Conclusions: This review presents that HD patients respond similarly in most physiological variables regardless of sex. Though, many studies discussing maximal oxygen consumption, functional capacity, six-minute walk distances, and grip strength strongly suggest that men benefit more.
Open Access
The Influence of Diabetes Medications on the Associations Between BMI and Cardiovascular Health Risks
(2023-03-28) Szivos, Andrew Kenneth; Kuk, Jennifer
The purpose was to observe the influence of diabetes medications on the association between body mass index (BMI) and cardiovascular health (CVH). Individuals with type 2 diabetes (T2D) from the National Health and Nutrition Examination Survey (NHANES Continuous 1999-2018) were grouped by diabetes medications with similar body weight side effects. There was a positive association between BMI for triglycerides in the combination medications group (P<0.002). Conversely, there were negative associations between BMI for HbA1c in the weight gain medications group (P=0.02), and total cholesterol in the weight loss and weight gain medication groups (P<0.05). Finally, no associations were between BMI in any medication group for fasting glucose, blood pressure or high-density lipoproteins (P>0.05). Therefore, T2D medications may weaken or invert the commonly observed association between obesity and CVH. Thus, patients living with T2D and obesity may have better CVH compared to patients without obesity taking the same T2D medication.
Open Access
Children's Community-Based Guided Active Play; Influence on Physical Activity Participation and Cardiovascular Responses
(2023-03-28) Moghaddaszadeh, Asal; Belcastro, Angelo
It is well established that the decline in children’s physical activity (PA) participation contributes to increases in the prevalence of paediatric obesity, risks for developing cardiovascular disease and decreases in physical fitness. PA interventions that are regimented and conducted in structured environments, such as laboratories, hospitals and school-based curricula, have shown to improve healthy PA behaviours and health- related fitness (i.e., health-enhancing PA). The increased costs and labour intensiveness of these programs have raised questions about their attractiveness in recreational/community summer camps and/or after-school settings. The importance of community-based programming where play (i.e., free play [FP], active play [AP], guided active play [GAP]) may provide increased opportunities for children to be active and facilitate social interactions should not be overlooked when considering children’s PA participation. Previous studies have shown that in a simulated AP environment using cooperative games, children elicit a wide range of energy expenditures and percentage of time spent in moderate-to-vigorous PA (%MVPA). The overarching purpose of this dissertation was to use cooperative games in community summer camp programs for school-aged children to determine if select health PA behaviour outcomes (energy expenditure, intensity) and health-related fitness (blood pressure, aerobic fitness, body composition) improvements are associated with long-term GAP programs. The major findings are that: 1) energy expenditure (EE) and %MVPA associated with children’s GAP using cooperative games over an 8-week community summer camp are maintained and sufficient to improve blood pressure and estimated maximal oxygen consumption (VO2max; Ch. 3.2); 2) following a shorter (5-wk) GAP program, school-aged children showed statistically higher forearm vascular perfusion controlled by endothelial independent processes that preceded changes in estimated VO2max (Ch. 3.3); and 3) during development, PA tracking over 1 year intervals were moderately high when assessed by GAP and using cooperative games (Ch. 3.1). In conclusion, cooperative games within a longer-term community summer camp GAP program are effective in sustaining health-enhancing PA and improving school-aged children’s health and fitness. PA participation over a one-year period for GAP using cooperative games is stable in children 5-12 years. A community camp that includes GAP programming with cooperative games seems to be an effective strategy to engage children in health-enhancing PA during time away from school (i.e., afterschool, weekends, summer).
Open Access
Electrical stimulation effects on cell cycle and autophagy markers in MCF7 and MDA-MB-468 breast cancer cells
(2022-12-14) Habib, Ramy; Connor, Michael K.
Breast cancer is a major health problem commonly seen in women. Despite considerable advancements in cancer research, cancer incidence continues to increase and cancer remains the second cause of death globally. It is crucial to further improve current cancer therapies and investigate novel treatments. This study evaluates the effects of electrical pulse stimulation (EPS) on breast cancer cells. This is based on previous work on myoblasts, cancerous rhabdomyosarcoma cells, and MCF7 breast cancer cells. EPS of MCF7 and MDA-MB-468 breast cancer cells revealed alterations in cellular signaling that suggest cell cycle arrest by autophagy. An Akt inhibitor was used to identify the role of Akt in the EPS response on breast cancer cells. This adds to a working model of cell cycle arrest by autophagy on cancer cells subject to EPS, and is a promising novel therapy that can be used to induce intrinsic cellular arrest mechanisms in cancer cells.
Open Access
Sex Differences in Skeletal Muscle Endothelial Cells
(2022-12-14) Garland, Elizabeth Jane; Haas, Tara
The proper functioning of endothelial cells (ECs) is often impaired during obesity-related disorders. Our lab’s previous data demonstrated sex differences in mitochondrial functioning and angiogenic capacity in adipose microvascular ECs. The goal of this study was to identify potential sex differences in lipid handling and metabolic capacities of skeletal muscle ECs. To achieve this, ECs were isolated from hindlimb skeletal muscle of mice and treated in culture to mimic obesogenic-like conditions. I found higher proliferation and lipid storage in female ECs in control conditions. In control and obesogenic-like conditions, females expressed higher levels of lipid handling genes, while males displayed greater Hk2 expression. Obesogenic-like conditions resulted in increased expression of Pfkfb3 in females, and decreased insulin sensitivity in male ECs only. These data provide evidence of sex-related differences in skeletal muscle ECs which can help to identify how their response to altered nutrient environment may in turn affect tissue health.
Open Access
Nonlinear analysis of the effects of vision and postural threat on upright stance
(2022-12-14) Weinberg, Sara Elizabeth; Cleworth, Taylor
The ability to control and maintain upright stance is crucial for humans to interact with their surroundings, allowing humans to navigate through environments. Behaviour during upright stance was examined using nonlinear methods to provide additional insight into postural threat (height) effects on postural control. Linear methods fail to address the nonstationary behaviour of the human body, while a nonlinear approach considers the underlying dynamics of postural sway. Linear measures identified increases in amplitude at 3.2 m (HIGH) compared to ground level (LOW), but no change with eyes closed (EC). Nonlinear measures identified decreases in all recurrence quantification analysis (RQA) variables in the HIGH and EC condition. The changes in sway dynamics might represent increased randomness and adaptability in response to increased fear (HIGH) or decreased sensory information (EC). This study demonstrates how including an RQA could provide a more informative analysis than linear measures alone.
Open Access
Neural Correlates of Unimanual and Bimanual Eye-Hand Coordination across Healthy and Dementia-Risk Populations
(2022-12-14) Rogojin, Alica; Sergio, Lauren E.
Eye-hand coordination is essential to our functional independence and relies on communication between widespread brain regions for successful unimanual and bimanual motor control. Eye-hand coordination performance has been shown to differ between the sexes, as well as between healthy aging individuals and those with dementia risk. The studies included within this dissertation were designed to characterize the structural and functional neural correlates of skilled movements across various populations in order to gain a better understanding of previously reported behavioural performance differences. The first two studies investigated changes in structural and functional integrity, respectively, of brain networks that may underlie known visuomotor behavioural deficits in older adults with an increased genetic (APOE e4) risk for Alzheimer’s disease. Alzheimer’s disease is thought to be a disconnection syndrome with characteristic patterns of disruption to structural and functional connectivity in the brain. A visuomotor task requiring the integration of different cognitive and motor domains via communication across multiple brain regions presents one way to test the integrity of these brain networks. The anatomical, diffusion-weighted, and resting state functional connectivity imaging data revealed that in older adult APOE e4 carriers, visuomotor deficits were predicted by i) lower grey matter volume and thickness of medial temporal lobe regions, ii) lower white matter integrity in several major tracts, and iii) decreased functional connectivity within the default mode and dorsal attention networks, in advance of any cognitive deficits. Historically, sex differences in unimanual and bimanual eye-hand coordination have also been observed, and a better understanding of the neural correlates of these differences could inform clinical practices on how to better tailor bimanual movement-based rehabilitation to the individual. The third study investigated the sex differences in functional connectivity of bimanual control, demonstrating connectivity differences between men and women despite equivalent behavioural performance. Taken together, these data provide novel insight into the neural correlates underlying one of our most fundamental human behaviours, eye-hand coordination, and their potential clinical implications.
Open Access
Populating an Indicator of Serious Paediatric Fall Injuries across Age and Public Health Units in Ontario
(2022-12-14) Mahboob, Mishel; Macpherson, Alison
Fall injuries among children and youth represent a significant burden to public health. Currently, there is no indicator assessing serious fall injuries in children. The purpose of this study was to populate an indicator of serious fall injuries within the paediatric population (0-19 years) using existing ICD-10 coded hospitalization data. The Discharge Abstract Database was used to examine all fall-related hospitalizations in Ontario from 2010-2019. Rates per 100,000 population and rate ratios were calculated for all fall-related and serious fall injuries; serious falls accounted for 3,652 hospitalizations. The highest rates for all fall-related and serious fall injuries were reported in rural health units. The mechanisms of serious fall injuries were highest among males 10-14 and 15-19 from skis, blades, skates, and boards, whereas rates were highest among females 0-4 from stairs and 5-9 from playgrounds. This indicator can be used to prompt action to reduce serious fall injuries in children.
Open Access
The Psychology of Athlete Selection: Perceptions and Processes
(2022-12-14) Robinson, Kathryn Dianne; Baker, Joseph
The objectives of this dissertation were to explore the factors influencing talent wastage within sport and to illuminate areas of improvement for athlete selection practices. To accomplish these objectives the research program used both qualitative and quantitative approaches. Chapter 2 involved a narrative review of the literature to identify factors affecting selection accuracy within and beyond the sport domain. In Chapter 3, a PRISMA-based systematic review was conducted on the literature examining the accuracy of the professional sport draft system in North America. The next two chapters utilized a qualitative design, where the research question, data collection, and data analysis were all guided by a pragmatistic paradigm. More specifically, these chapters explored a group of expert distance running coaches’ subjective beliefs about ‘talent’ (Chapter 4) and talent selection practices (Chapter 5). Finally, in Chapter 6, a tool was developed, and a pilot experiment was conducted to examine the decision-making-behaviour of a group of rugby coaches. Several key findings were revealed through this program of work. Chapter 2 highlighted athlete selection is affected by a complex interaction of various factors. Such factors may include confusing or conflicting beliefs about talent, political and system-wide pressures, and cognitive biases and other decision-making fallibilities. Chapter 3 revealed inefficiencies within the North American draft systems and provided insight into some of the selection challenges at even the most resource-rich stages of the sport pathway. The qualitative analyses showed distance running coaches perceived talent to be complex, nuanced, and easily confused with other closely related terms (Chapter 4) and that coaches made selections using both formal and informal selection strategies that were influenced by their personal and systemic constraints (Chapter 5). Finally, findings presented in Chapter 6 emphasized the difficulties in designing a tool to assess decision-making and selection behaviour in the context of sport. These difficulties are believed to be connected to the individual differences in how ‘success’ is measured and how ‘talent’ is defined and assessed. In summary, findings of this research program suggest talent is a prevalent and pervasive construct that influences the way coaches think about and select athletes.
Open Access
'It's more than a sport's facility, it's a safety net for youth': Exploring the Utility of Trauma-and Violence-Informed Sport for Development (TVISFD) Programs with Maple Leaf Sport and Entertainment's LaunchPad
(2022-12-14) Ferreira Gomes, Julia; Hayhurst, Lyndsay M.
Gender-based violence (GBV) has disproportionately impacted the lives of women, girls, and gender diverse people in Canada. In a partial response to escalating GBV rates, a growing movement towards trauma- and violence-informed (TVI) healthcare has emerged in Canada. TVI physical activity has been proposed as an effective approach to support individuals with trauma as an adjunctive treatment to usual care. The focus of this thesis was to explore how use of a TVI approach to Sport For Development programs at Maple Leaf Sports and Entertainment’s LaunchPad may support vulnerable youth. Semi-structured interviews and demographic surveys were conducted with fifteen (n=15) full-time staff, hourly youth workers, and program participants. Findings suggested that community member representation amongst staff enhanced participants’ and youth workers’ perceptions of safety. Program features that aligned with TVI physical activity included: 1) creating emotionally and physically safe environments; and 2) providing a capacity-building and strengths-based approach.
Open Access
Bicycles for Mutual Aid: A Participatory Action Research Project with the Toronto Bike Brigade
(2022-12-14) Nachman, Jessica Rodica; Hayhurst, Lyndsay M.
The term “bicycles for development” (BFD) has emerged to consider bicycling for achieving similar goals to sport for development (SFD) – or the use of sport as a vehicle for social development (Kidd, 2008). This project builds on previous BFD work by forging novel directions for research on BFD, including: 1) how bicycle-related activities contribute to COVID-19 recovery, specifically in promoting a more environmentally sustainable and equitable world for vulnerable populations; and 2) the ways that cycling can be taken up by QT and BIPOC to challenge existing systems of inequality. Guided by a participatory action research project in partnership with The Bike Brigade, the data collection methods used in this project included arts-based methods and semi-structured interviews. Findings suggested that QT and BIPOC cyclists were taking up bicycling through mutual aid frameworks to support their communities and respond to the COVID-19 pandemic and exacerbated inequality. Further research is needed in the fields of BFD and SFD that: 1) prioritize and center diverse perspectives on bicycling; and 2) engage with creative methodologies such as arts-based approaches.
Open Access
The Effect of Concussion History on an On-Field Assessment of Cognitive-Motor Integration in Male and Female Varsity Athletes: Reliability of the HurtSHynes™ Test
(2022-12-14) Amaral, Christina Amanda; Hynes, Loriann M.
Current metrics for assessing athlete performance following concussion measures cognition followed by movement. Success in sport performance requires the simultaneous integration of cognition and action, cognitive-motor integration (CMI). Athletes with a history of concussion (HOC) exhibit performance deficits on CMI tasks. Here, we observed the effects of concussion history on a new CMI sideline assessment task, the HurtSHynes™ Test, in varsity student-athletes. Females with HOC were the least likely to incur an error and were on average faster than females with no HOC. Males with HOC were on average slower than males with no HOC. Performance of females with HOC suggests that females may have better visuomotor skill recovery than males post-injury. The HurtSHynes™ Test demonstrated excellent inter-rater reliability (ICC > 0.90) and good-to-excellent intra-rater reliability (ICC > 0.75). We suggest this measure may be useful as a quick and objective measure to assist in guiding return-to-play decisions.
Open Access
Advancing Understanding of Early Specialization in Youth Sport
(2022-12-14) Mosher, Alexandra Patricia; Fraser-Thomas, Jessica; Baker, Joe
Objective: The overarching purpose of this dissertation was to better understand early specialization, through two main objectives. The first objective was to determine research gaps in existing literature, and the second was to develop a valid tool for measuring specialization based on the identified gaps. Methods: In Chapter Two, a systematic review of the literature was conducted. Both non-data driven and data-driven studies were included to ensure a comprehensive understanding of the literature. Chapter Three describes a two-part study. In part one, 362 athletes were coded as specializers or non specializers depending on three different indicators used in previous research. In part two, 237 athletes were then coded to determine whether they were elite, pre-elite or nonelite in adulthood. Lastly, in Chapter Five, a Delphi-approach included 16 experts in the field to test elements of validity of the Sport Exposure Scale. Results: Findings from Chapter Two indicated inconsistent definitions and measures used in the literature and a clear discrepancy between key components of early specialization and approaches used to classify early specializers. Chapter Three results showed the proportion of athletes classified as specialisers varied depending on the method used and that there was no clear advantage or disadvantage to being a specializer based on skill-level achieved. Finally, in Chapter Five, the content and face validity of the Sport exposure Scale was established when the Delphi panellists reached consensus for each item. Conclusion: This dissertation highlighted gaps in the literature around early specialization and showed the implications of measurement imprecision. This dissertation attempted to provide a solution to these issues by creating the Sport Exposure Scale, which was designed to help advance not only our understanding of early specialization, but sport participation pathways in general. This dissertation provides areas for future research and has significant implications for research, stakeholders and society more broadly.
Open Access
Informing Practice for the Development and Dissemination of Physical Activity Messages Targeting Parents of Children with Disabilities
(2022-12-14) Larocca, Victoria Filomena; Basett-Gunter, Rebecca
Children with disabilities (CWD) engage in less physical activity (PA) compared to children without disabilities. There has been a call to develop evidence-informed strategies to promote PA among CWD. Considering that parent support is one of the strongest correlates of PA among CWD, it is important to develop strategies that can promote parent support for PA through message development and dissemination. At a high level, this dissertation is guided by the theory of planned behaviour (TPB) and the multi-process action control (M-PAC) model. Phase 1 utilized a pre-post quantitative design to examine the effects of various PA messages on psychosocial antecedents of support for PA and self-reported parent support for PA among parents of CWD. Baseline parent support acted as a moderator on the effects of messages on attitudes toward child PA, subjective norms toward child PA, subject norms toward parent support for PA, and planning. Parents preferred the inclusive message most. Phase 2 utilized a systematic scoping review guided by the framework for knowledge transfer to identify strategies that can inform practices regarding the development and dissemination of PA messages. Strategies unique to parents of CWD were identified for message development (e.g., targeting salient barriers) and dissemination (e.g., utilizing preferred sources). Phase 3 addressed the lack of targeted information for parents of CWD highlighted in Phase 2. A mHealth program was developed to disseminate targeted messages to encourage planning for PA support among parents of CWD. Utilizing qualitative methodologies (i.e., thematic analysis) and informed by the PRACTical planning for Implementation and Scale-up (PRACTIS) guide, Phase 3 identified facilitators (e.g., user-friendly interface) and barriers (e.g., too much information) to the implementation of the mHealth program. Results also identified suggestions for implementation improvement (e.g., quick reminders and condensed information) as well as credible organizations to support implementation (e.g., local organizations). This research collectively advances the understanding of the development and dissemination of PA messages targeting parents of CWD. The results of this research offers strategies to inform PA message practices to enhance support for PA among parents of CWD.