The four studies of this thesis provide an overview of the epidemiology of physical activity in Canada. In the first study two methods of coding activities used in estimating leisure-time physical activity energy expenditure (LTPAEE), from a questionnaire including 21 specific activities, and up to three “other” activities were compared. The authors assessed whether the assignment of activity intensity for “other” activities has an effect on LTPAEE and the classification of respondents as physically active versus inactive. The results indicate that the population classification of activity level is not affected by the intensity code; however, individual level LTPAEE is under-estimated from light and vigorous activities and over-estimated from moderate activities using the current method. In study two the proportion of Canadians meeting Canada’s physical activity guidelines for moderate and vigorous activities was estimated. The prevalence of adults reporting no activity has not changed since 1994/95 and the prevalence of meeting the guidelines has increased by about 11%. Men, younger adults, those with higher income and lower body mass index (BMI) meet the guidelines more often than their peers. The epidemiology of walking among Canadians between 1994 and 2007 was assessed in the third study. Walking was the most popular activity, regardless of age, sex, BMI or income group; however, only 30% of walkers walked regularly. Women, older adults, those with lower BMI and lower household income walk regularly more often than their counterparts. Women, older adults and lower income Canadians tended to derive 100% of their total LTPAEE from walking. An evaluation of whether meeting the guidelines for physical activity was associated with lower odds of chronic conditions and reporting fair/poor health was undertaken in study four. After adjustment for covariates, the odds of type 2 diabetes, obesity and reporting fair/poor health were significantly higher among those not meeting the guidelines for both sexes and for high blood pressure among women. Together these findings provide an understanding of the limitations of estimating LTPAEE, provide estimates of the proportion of Canadians meeting the guidelines for physical activity and provide insight into the relationship between meeting the guidelines and chronic conditions. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2009-06-18 16:18:44.998

Health research has demonstrated that regular leisure-time physical activity (LTPA) during pregnancy and the postnatal period may play a crucial role in managing the physical and psychological challenges that women face during these times of transition. The purpose of this dissertation was to investigate LTPA patterns during pregnancy and in the postnatal period and identify social-cognitive correlates associated with regular LTPA. Three inter-related studies were conducted. The purpose of Study 1 was to conduct an in depth month-to-month investigation of LTPA from 3 months prior to conception to 7 months following childbirth. An assessment of 309 pre and postnatal women revealed that LTPA started to decline in the first trimester of pregnancy, continued to decline at a steady rate until childbirth and then increased during the postnatal period. In addition to illustrating the average growth curve, the results from the multi-level moding analyses indicated substantial individual variability around the average growth curve. Future research should identify social cognitive factors that are associated with LTPA during this time of transition. Accordingly, Study 2 investigated psychosocial correlates of LTPA during pregnancy. The study engaged pregnant women in the listing of salient barriers to LTPA at 4 different time points during pregnancy (e.g., pregnancy weeks 18, 24, 30 and 36) and examined if barrier self-efficacy as well as a general measure of exercise self-efficacy were associated with LTPA during pregnancy. A total of 1168 barriers were content analyzed, yielding nine major themes. Hierarchical regression analyses supported both forms of self-efficacy as predictors of LTPA. While Study 2 examined LTPA during pregnancy, Study 3 focused on the postnatal period. The first objective was to identify postnatal women's perceived LTPA barriers and outcome expectations. In general, the barriers reported were consistent with barriers experienced by both asymptomatic and symptomatic populations as well as previous research examining barriers to exercise among postnatal women. The results of the open-ended outcome expectation elicitation generated a large number of physical, psychological and social outcome expectations. Approximately 90% of all outcome expectations listed under each category were classified into four groups. The second objective of Study 3 was to examine if outcome expectation likelihood, exercise self-efficacy and barrier self-efficacy were associated with LTPA. In support of our hypothesis, and consistent with social cognitive theory, self-efficacy was significantly associated with LTPA. For many women engaging in regular LTPA during pregnancy and following the birth of a child is a challenge. The average growth curve results from Study 1 are promising; however the random effects analyses was significant indicating substantial individual variability about the average growth curve. Study 2 and Study 3 identified a number of salient barriers to LTPA which may hinder the initiation and maintenance of regular LTPA. Study 3 also identified salient outcome expectations that may severe a motivational factors to engage in LTPA. The results suggest that self-efficacy represents an important social cognition is linked to higher levels of LTPA in the postnatal period. In conclusion, barrier and exercise self-efficacy may be important targets for intervention efforts to promote LTPA during pregnancy. / Thesis / Doctor of Philosophy (PhD)

Despite the widely documented physical, psychological, and social benefits of regular participation in physical activity (Bauman & Campbell, 2001; Blair, Kohl & Barlow, 1995; Paluska & Schwenk, 2000; U.S Department of Health & Human Services, 1996), less than half of the Australian population participate in 'sufficient' levels of physical activity in terms of time and frequency of participation (Bauman, Ford & Armstrong, 2001). Thus the examination of social psychological determinants of regular participation in leisure-time physical activity is important. A mixed methods approach was adopted to identify and test the important social psychological determinants of regular participation in leisure-time physical activity. Phase one of the study was qualitative in nature and adopted a grounded theory approach. A number of important themes emerged from the qualitative phase, including: definitions and meanings of physical activity; physical activity and choice, obligation, reasons for participation; enjoyment of physical activity; changing perceptions and influences on physical activity from childhood to adulthood; and priority of physical activity. The interrelations between these themes and their impact on regularity of participation were explored. These findings, along with theoretical propositions and evidence from previous studies, contributed to the development of a model of the social psychological determinants of regular participation in leisure-time physical activity. They also contributed to the development of items to measure important concepts in the model. Phase two was quantitative in nature and used structural equation modelling to test the model. The quantitative phase involved a sample of 250 people aged 19-87 years living in an Australian capital city. Self-report questionnaires measured regularity of participation in leisure-time physical activity (dependent variable), leisure-time physical activity behaviour regulation, intrinsic motivation towards leisure-time physical activity, enjoyment of leisure-time physical activity, and priority of leisure-time physical activity (independent and mediating variables). Each of the independent and mediating variables was multidimensional in nature, the components of which were assessed using confirmatory factor analysis in structural equation modelling prior to the testing of structural models. After some adjustment, the predictors were satisfactorily represented by their respective multifactor models, except intrinsic motivation, which was best represented by a single factor model. Following modification, the proposed model of the social psychological determinants of regular participation in leisure-time physical activity was found to be a good fit of the data. Relationships within the model indicated the importance of the priority of leisure-time physical activity factors in the prediction of regular participation in leisure-time physical activity. The influence of preference for leisure-time physical activity on regular participation in leisure-time physical activity was mediated by level of priority and making time for leisure-time physical activity. That is, people who preferred to participate in leisure-time physical activity over other types of leisure tended to make it a higher priority, and, in turn, tended to make time to participate. Making time was subsequently associated with increased regularity of participation in leisure-time physical activity. The enjoyment factors influenced regular participation in leisure-time physical activity through their influence on preference for leisure-time physical activity. Activity enjoyment had a positive influence on preference and enjoyment dependent on surroundings had a negative influence. However, in the overall model, the behaviour regulators and intrinsic motivation attenuated the influence of the enjoyment factors on preference for leisure-time physical activity. This suggested that people's underlying behaviour regulators and levels of intrinsic motivation have a similar influence on their preference for leisure-time physical activity as their feelings of enjoyment. However, behaviour regulators and intrinsic motivation appear to be more powerful influences of preference than enjoyment. Intrinsic motivation towards leisure-time physical activity positively influenced regular participation in leisure-time physical activity through its influence on preference for leisure-time physical activity. It also had a direct influence on regularity of participation. Thus, people who were more intrinsically motivated tended to participate more regularly in leisure-time physical activity partly because they formed preferences for physical activity over other types of leisure. Furthermore, the direct influence of intrinsic motivation on regular participation suggested that there were explanations, beyond that of preference and priority, for why those who were intrinsically motivated tended to participate more regularly in leisure-time physical activity. The behaviour regulators of external regulation (negative), introjected regulation (positive) and identified regulation (positive) influenced regularity of participation in leisure-time physical activity mostly through their influence on intrinsic motivation towards leisure-time physical activity. That is, when people felt their physical activity was externally regulated, they felt less intrinsically motivated to participate and this was subsequently associated with less regular participation. On the other hand, when people were regulated by introjection and identification, they tended to feel more intrinsically motivated and this was subsequently associated with more regular participation. External regulation and introjected regulation also had a direct negative influence on preference for leisure-time physical activity and perceptions of the availability of time, respectively. Thus, people who felt externally regulated tended to have less preference for leisure-time physical activity and those who were regulated through introjection were more likely to perceive that they did not have the time to participate. This study contributes to the body of knowledge by highlighting the importance of preferences and prioritisation on perceptions of time availability, and subsequently, regularity of participation in leisure-time physical activity. It also demonstrated that behaviour regulators and intrinsic motivation are important determinants of regular participation in leisure-time physical activity in a general community sample. These findings have theoretical and practical implications for researchers, leisure professionals, and policy makers. They also suggest a number of significant areas of further research.

Introduction: The benefits of leisure-time physical activity on mental and physical health among older adults are well documented, but few studies have explored the association between depression and leisure-time physical activity within a theoretical framework. Objective: The purpose of the present study was to identify the association between depression and leisure-time physical activity among community-dwelling, Canadian adults aged 65 and older, using a modified version of the International Classification of Functioning, Disability and Health (ICF) framework. Method: The present study included a weighted sample of 3,785,145 community- dwelling, seniors aged 65 years or older who participated in the Canadian Community Health Survey (Cycle 2.1). Univariate and multiple logistic regressions were used to examine the cross-sectional association between depression-related disorders and leisure-time physical activity in the context of chronic physical conditions and psychosocial factors. Results: Older adults reporting depression-related disorders were less likely to participate in leisure-time physical activity after adjusting for relevant psychosocial factors (odds ratios (ORs) ranged from 0.76 to 0.79, p < 0.001). This association was partially mediated by activity limitations associated with depression-related disorders. Similar results were observed between chronic physical conditions and participation in leisure-time physical activity. Conclusion: Although the present study was unable to identify the temporal relationships among study variables, the results provide clinicians who care for older adults with depression and/or chronic physical diseases with potentially useful information on the benefits of physical activity. They also provide evidence in support of community-based exercise or leisure-time physical activity program for seniors who are physically inactive to prevent chronic mental or physical illnesses and reduced quality of life

Introduction: The benefits of leisure-time physical activity on mental and physical health among older adults are well documented, but few studies have explored the association between depression and leisure-time physical activity within a theoretical framework. Objective: The purpose of the present study was to identify the association between depression and leisure-time physical activity among community-dwelling, Canadian adults aged 65 and older, using a modified version of the International Classification of Functioning, Disability and Health (ICF) framework. Method: The present study included a weighted sample of 3,785,145 community- dwelling, seniors aged 65 years or older who participated in the Canadian Community Health Survey (Cycle 2.1). Univariate and multiple logistic regressions were used to examine the cross-sectional association between depression-related disorders and leisure-time physical activity in the context of chronic physical conditions and psychosocial factors. Results: Older adults reporting depression-related disorders were less likely to participate in leisure-time physical activity after adjusting for relevant psychosocial factors (odds ratios (ORs) ranged from 0.76 to 0.79, p < 0.001). This association was partially mediated by activity limitations associated with depression-related disorders. Similar results were observed between chronic physical conditions and participation in leisure-time physical activity. Conclusion: Although the present study was unable to identify the temporal relationships among study variables, the results provide clinicians who care for older adults with depression and/or chronic physical diseases with potentially useful information on the benefits of physical activity. They also provide evidence in support of community-based exercise or leisure-time physical activity program for seniors who are physically inactive to prevent chronic mental or physical illnesses and reduced quality of life

abstract: Vitamin C is a micronutrient with many important physiological roles. It can function as a reducing agent, a free radical scavenger, and an enzyme cofactor. Much research has examined the potential of vitamin C supplements to enhance exercise capacity in trained athletes; however, little is known regarding the effects of vitamin C supplements on the promotion of leisure-time physical activity in the general population. This area deserves attention since 1/3 of Americans have below adequate vitamin C status, and since aversion to exercise, fatigue, and altered mood states are the earliest signs of poor vitamin C status. This study analyzed the effect of supplementing 500 mg twice daily of vitamin C on self-reported leisure-time activity levels and mood states in young men. Twenty-nine healthy, young men, aged 18-35 years, were stratified by age, BMI, smoking status, and plasma vitamin C concentrations and assigned to either a control (CON) or experimental group (VTC) for the 8-week randomized, double-blinded, parallel arm trial. Subjects were instructed to keep track of their leisure-time physical activity by filling out the validated Godin Leisure-Time Exercise Questionnaire weekly for the entire study. In addition, subjects took the self-administered Profile of Mood States (POMS) at baseline, week 4, and week 8 to observe mood states. Plasma vitamin C concentrations were analyzed at the initial screening, week 4, and week 8 of the study. Plasma vitamin C concentrations significantly differed by group at week 4 and week 8. Furthermore, vitamin C supplementation significantly increased self-reported mild, moderate, and strenuous activity levels during the 8-week trial. Overall, total physical activity scores increased nearly 50% in the VTC group as compared to 18% in the CON group (p=0.001). However, mood states were not significantly impacted by vitamin C supplementation during the trial. This study provides the first experimental evidence that supplementing 500 mg of vitamin C twice daily can be effective in increasing leisure-time physical activity in healthy young men. This study, however, was unable to link improvements in physical activity rates to improved mood states. Since sedentary behaviors have been implicated in the rise of obesity in the U.S., further research should be conducted to substantiate the finding that vitamin C supplementation increases physical activity. / Dissertation/Thesis / M.S. Nutrition 2012

Orientador: Eduardo Kokubun / Banca: Alex Antonio Florindo / Banca: Sandra Lia do Amaral / Resumo: O objetivo desse estudo foi investigar associações entre nível, oferta de Atividade Física (AF) no trabalho e AF de lazer. Foi realizado um estudo transversal de base populacional. Participaram do estudo 864 trabalhadores com idade média e desviopadrão de 41 (± 13,4) anos, sendo 451 homens e 413 mulheres e eles responderam o Questionário Internacional de AF (versão longa- classificados em ativos e sedentários de acordo com o nível de AF de lazer), o Questionário baseado no modelo Transteorético (Estágios de Prontidão - classificados em fase de adoção e fase antecedentes), o Questionário sobre convênios e instalações para a prática de AF pela empresa e o Questionário sócio-demográfico. Para verificar as associações foi realizada a Regressão de Poisson no programa STATASE.10, obtendo a Razão de Prevalência (RP) com Intervalo de Confiança (IC - 95%). Como variáveis dependentes utilizamos o sedentarismo (nível de AF de lazer) e fase antecedentes (participação em AF de lazer). Para as variáveis independentes utilizamos: sexo, idade, índice de massa corporal (IMC), escolaridade, nível sócio-econômico, nível de AF no trabalho, oferta de ginástica laboral, participação na ginástica laboral e oferta de programas de condicionamento físico (PCF) através de convênios e instalações no local de trabalho. Os resultados indicam que os trabalhadores do sexo masculino são menos sedentários quando comparados com as trabalhadoras do sexo feminino. Para o sexo masculino, menor nível sócio-econômico está associado ao sedentarismo e a oferta de PCF oferecidos através de convênios está associada a níveis mais elevadosl de AF de lazer. Para o sexo feminino, maior IMC e menor nível sócio-econômico foram associados ao sedentarismo. Com relação a participação em AF de lazer o sexo feminino tem menos chances de estarem na fase de adoção... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to investigate the associations between Physical Activity's (PA) level and PA's offer at worksite and Leisure time PA. The Population-based cross-sectional study was realized with 864 workers with average age and standard deviation 41 (± 13,4) years old, being 451 men and 413 women. They answered the International PA Questionnaire (long version - classified in activity and sedentary according to leisure time PA's level), the Questionnaire based on Transteorethic Model (Stages of change - classified in adoption and antecedents phases), the Questionnaire about facilities and installations PA's practice in the worksite and the demographic-status Questionnaire. The Poisson Regression in the STATASE.10 program, getting the Prevalence Ratio (PR) with Confident Interval (CI - 95%) was conducted to verify the associations between the variables. The dependents variables were the sedentarism (leisure time PA's level) and antecedents phase (leisure time PA's participation). For the independents variables were used: sex, age, body mass index (BMI), schooling level, social status, PA's level in work, stretchbreak's offer, stretch-break's participation and fitness program's (FP) through facilities and installations PA's practice in the worksite. The results indicated that the male workers are less sedentary than female. For men the lower social status was associated with sedentarism and the FP facilities was associated with bigger leisure time PA's level. For female, bigger IMC and lower social status were associates with sedentarism. About leisure time PA's participation, the female has less chance to be in the adoption phase than male. The variables associated to leisure time PA's participation for male are: bigger schooling and social status... (Complete abstract click electronic access below) / Mestre

Little is known about leisure-time physical activity (LTPA) habits of Arab immigrants in Canada. Leisure-time physical activity has been linked to decreased risks for cancer, cardiovascular disease, and all causes mortality and increased life expectancy. Socioeconomic status has been recognized as a significant factor affecting health and wellbeing due to its impact on individuals’ attitudes, experiences, and exposure to several risk factors. The purpose of this cross-sectional descriptive study was to explore the levels of participation in LTPA among adult Arab immigrants in central Alberta, Canada, to examine the socioeconomic determinants of LTPA, and to investigate which individual, social, and environmental factors contribute to LTPA participation. Electronic surveys were used to collect data from a sample of 376 adults. The socioecological model and systems theory were used as the theoretical foundations to guide this research. Descriptive and multiple regression analyses were performed using SPSS. Around 40% of participants were physically active. As participants attained higher degrees, earned more money, and had occupations requiring less physical effort, their levels of LTPA increased. The social conditions in which the participants live also affected their levels of LTPA. Being more familiar with the health benefits and having fewer barriers to exercise predicted an increase in LTPA, whereas higher self-efficacy seemed to predict a decrease in LTPA. Family and friends’ support for exercise increased the levels of LTPA of participants. And finally, more environmental support for exercise predicted a decrease in LTPA levels among participants. Findings from this research have the potential to design and implement targeted LTPA recommendations and interventions for Arab immigrants.

<p>The purpose of this dissertation was to use an integrative theoretical framework to examine the individual and environmental factors associated with leisure-time physical activity (LTPA) for persons living with spinal cord injury (SCI). Using a systematic approach, three studies were conducted to: (1) survey the accessibility and availability of physical activity facilities for Canadians living with mobility disabilities, (2) test an integrative, theoretical framework for understanding LTPA among people with SCI, and (3) implement a theory-based intervention that focuses on helping beginner exercisers living with SCI cope with salient individual and environmental LTPA barriers. </p> <p>Study 1 involved two sub-studies. Study lA used a modified version of the AIMFREE instrument (Rimmer et al., 2004) and provided evidence of the limited accessibility of fitness and recreational facilities (n=44) for persons with mobility disabilities. Study lB applied a geographical technique, Geographical Information Systems (GIS), to develop an objective proximity measure specific to persons with SCI. Results indicated a small, negative association between the objective presence of physical activity facilities and L TPA in a sample of persons with SCI (n=50), suggesting that living in close proximity to a facility which provides adaptive programming and equipment does not necessarily translate into greater LTPA for persons with SCI.</p> <p>As an extension of Study 1, Study 2 used structural equation modeling to conduct a cross-sectional examination of whether an environmental factor --neighbourhood perceptions--could enhance the Theory of Planned ehaviour's (TPB; Ajzen, 1985) ability to explain LTPA intentions and behaviour in persons with SCI (n=246). Results indicated a small, negative association between perceived wheeling infrastructure and LTPA intentions. However, perceptions of neighbourhood aesthetics and wheeling infrastructure did not explain significant variance in either L TPA intentions or behaviour, beyond that accounted for by the TPB constructs, suggesting that these eighbourhood factors do not enhance the TPB's ability to explain LTPA behaviour.</p> <p>Lastly, Study 3 used a randomized, controlled design to examine the effects of a 10-week action and coping planning intervention on enhancing LTPA and coping self efficacy in exercise intenders living with SCI (n=47). Results indicated greater LTPA for participants who formed action plans and coping plans (A+C condition) than for the participants who only formed action plans (A condition). Furthermore, the A+C condition had greater confidence to schedule their L TPA and overcome L TPA-related barriers than the A condition. These findings provide evidence of the benefits of supplementing action plans with coping plans for enhancing L TP A and coping self-efficacy beliefs among exercise intenders living with SCI. </p> <p>Together, these three studies provide a broader understanding of L TPA correlates and determinants in people with SCI, and provide evidence of the efficacy of multiple planning strategics for promoting L TPA in persons with SCI. The results provide an impetus for extending the scope of the research on the physical environment and LTPA towards persons with mobility disabilities. Moreover, the findings demonstrate the value of theory-based research for identifying the multidimensional correlates and determinants of LTPA, and for designing effective LTPA-enhancing interventions in persons with SCI. </p> / Thesis / Doctor of Philosophy (PhD)

<p>Using a cross-sectional design, Bandura's (1986) Social Cognitive Theory and Self-Efficacy Theory (1977) were used as a framework to determine whether wheelchairuse self-efficacy and exercise barrier self-efficacy mediate the relationship between wheelchair mobility and leisure-time physical activity (LTPA) in people with spinal cord injury (SCI). Fourty-six manual wheelchair users (76.1 % male), with varying levels of SCI (80.4% paraplegic, 47.8% complete injuries) participated in this study. Participants completed The Wheelchair Skills Test version 4.1 (Wheelchair Skills Test Version 4.1 [WST 4.1],2008) which measured wheelchair mobility, a modified barrier self-efficacy questionnaire (McAuley & Mihalko, 1998) which measured exercise barrier self-efficacy, the Wheelchair Mobility Confidence Scale (WMCS; Rushton & Miller, 2009) which measured wheelchair-use self-efficacy, and the Physical Activity Recall Assessment for people with SCI (PARA-SCI; Martin Ginis, Latimer, Hicks & Craven, 2005) which measured LTPA. It was hypothesized that (1) there would be a positive relationship between wheelchair mobility and LTPA, and (2) wheelchair-use self-efficacy and exercise barrier self-efficacy would mediate this relationship. Using linear regression models, a positive association between wheelchair mobility and LTPA was established (β = .29, p < .05). Exercise barrier self-efficacy was a significant partial mediator, explaining 47.7% ofthe variance in the mobility-LTPA relationship. Wheelchair-use selfefficacy was a non-significant mediator. This thesis has practical and theoretical implications for understanding and improving LTPA participation and represents the first study to determine the relationship between wheelchair mobility, self-efficacy, and LTPA in people living with SCI.</p> / Master of Science (MS)