Background: While the physical and mental health advantages of regular physical activity are evident, 68% of adult Canadians are not meeting PA guidelines. Over the last thirty years, exercise behaviour has been mostly studied under the guise of the social cognitive framework, but emerging findings have shown identity to demonstrate predictive validity with physical activity independent of social cognitions. Exercise identity has been associated with increased frequency, duration, and intensity of exercise behaviour. Despite the bivariate correlation between identity and PA, the literature currently lacks longitudinal research to enhance the understanding of identity formation in new exercisers. Objective: The purpose of this study was to understand changes in identity among new exercisers based on the Physical Activity Self-Definition model and investigate whether exercise identity can predict exercise behaviour variations over nine weeks. Methods: Participants for this study were healthy adults (18-65) who were recruited from local gyms and recreation centres in Victoria, BC. The inclusion criteria were that participants must be new exercisers (new exercisers are those who just decided to exercise regularly or started exercising for less than 2 weeks, before baseline measurement) who were not meeting the Canadian Physical Activity guidelines upon recruitment. The study used a prospective, observational design with four measurement periods across nine weeks. Demographics were collected and exercise identity, affective attitude, commitment, capability and exercise behaviour were measured using questionnaires. The exercise Identity questionnaire was administered at 1 week, 3 weeks, 6 weeks and 9 weeks. Data analysis and longitudinal models used HLM and descriptive were generated with SPSS. Results: Affective attitude and commitment had significant correlations with identity, and identity had a significant correlation with exercise behaviour across all measurement times. Affective attitude, however, was the only significant predictor of exercise identity change over time. Capability was not associated with exercise identity. Furthermore, identity did not predict change in exercise over time. Discussion: This study provided insight into some of the factors that influence shifting exercise identity of new exercisers by testing the physical activity self-definition model (Kendzierski & Morganstein, 2009a) with longitudinal modelling. Based on the present results, it is recommended that health promoters focus on designing enjoyable programs for their novice clients, and provide a positive affective attitude toward exercising during each session. Although, exercise behaviours of the participants improved significantly during the course of this study, exercise identity was not able to predict the variation in exercise behaviour over 9 weeks. Overall, exercise identity formation can be a time-consuming process in adults, however, engaging in identity-related behaviours that are enjoyable can accelerate this process. / Graduate

Problématique : Une femme enceinte sur deux est sédentaire au Québec. La sédentarité a des effets néfastes pour la santé des femmes enceintes et peut entraîner des conditions nuisibles au fœtus. Pourtant, l'activité physique est bénéfique pour la femme enceinte et le fœtus. But : Ce projet pilote avait pour objectif d’évaluer l’acceptabilité et la faisabilité du déroulement de l’étude et d’une intervention de promotion de l’activité physique auprès de femmes enceintes et d’estimer les effets sur leur sentiment d’auto-efficacité perçue et sur leur pratique d’activité physique. Méthode : Le devis consistait en une étude pilote composée d’un seul groupe avec un échantillonnage non-probabiliste de convenance. Les questionnaires du pré-test étaient remplis après le premier cours prénatal. Après le deuxième cours prénatal, l’intervention était administrée. Après le troisième cours prénatal, les questionnaires du post-test étaient remplis. Résultats : Dix femmes ont reçu l’intervention et ont complété le post-test pour un taux de 100% en ce qui a trait à la faisabilité de l’étude. L’analyse des données révèle qu’il n’y a pas de différence significative entre les moyennes obtenues lors du pré-test et le post-test en ce qui a trait aux deux sous-échelles de l’auto-efficacité (p=0.09 et 0.20) ainsi que celles de la pratique d’activité physique (p=0.15). Conclusion : L'acceptabilité et la faisabilité du déroulement de l’étude et de l’intervention sont soutenues par ce pilote. Un essai clinique randomisé à plus large échelle à l’aide d’une mesure objective en ce qui a trait à la mesure de l’activité physique est recommandé. / Problem: One out of two pregnant women in Quebec is sedentary. A sedentary lifestyle has negative effects on the health of pregnant women and can lead to harmful conditions for the fetus. However, physical activity offers many benefits for a pregnant woman and the fetus. Aim: The objective of this pilot project was to evaluate the acceptability and feasibility of the conduct of the study and an intervention promoting physical activity among pregnant women and to estimate the effects on their feelings of self-efficacy and their practice of physical activity. Methodology: The design consisted of a pilot study with a single group with convenient non-probabilistic sampling. Pre-test questionnaires were filled out after the first prenatal class. After the second prenatal class, the intervention was conducted. After the third prenatal class, the post-test questionnaire was filled out. Results: Ten women received the intervention and completed the post-test for a 100% feasibility rate of this study. Analysis of the results revealed that there is no significant difference between the pre-test and post-test regarding the two subscales of self-efficacy (p=0.09 et 0.20) and the average practice of physical activity (p=0.15). Conclusion: The acceptability and feasibility of course of the study and intervention are supported by this pilot. A randomized clinical trial on a larger scale with objective measures is recommended.