The general purpose of this dissertation was to examine how self-efficacy, explicit exercise motives and implicit automatic associations with exercise influence exercise behaviour of sedentary adults. This dissertation is divided into three manuscripts. The first manuscript examined how self-selection influences the decision to enrol in an exercise program as well as in self-efficacy, explicit motives and implicit associations. Additionally, manuscript one sought to understand the role of self-selection bias in the adoption and maintenance of exercise over six months. A total of 290 inactive adults aged 35-65 completed the Multidimensional Self-Efficacy for Exercise Scale (MSES; Rodgers, Wilson, Hall, Fraser, & Murray, 2008), two Go/No Go Association Tasks (GNATs; Nosek & Banaji, 2001) to measure automatically activated associations of exercise, and the Exercise Motivations Inventory-2 (EMI-2; Markland & Ingledew, 1997) at baseline, three months and six months of an exercise program. Analysis of variance was used to test study hypotheses. At baseline, participants were grouped into three self-selection profiles: self-selection (n =126), self-selection with previous knowledge of the exercise program (n = 111), and those who did not enrol in the exercise program (n =53). Those in the self-selection groups had higher task, coping and scheduling SE, as well positive health exercise motives. No differences in implicit automatic associations with exercise were found. The influence of self-selection bias did not influence adherence or drop outs at three and six months across the three dependent variables.
Manuscript two investigated the role that self-efficacy, explicit motives and implicit automatic associations with exercise influence the intention behaviour gap. Those participants who enrolled in the exercise program and had no previous knowledge of the exercise program were included in this study resulting in a total of 141 participants (107 inclined actors and 35 inclined abstainers) aged 35-65. Analysis of variance, logistic regression, and moderation models were used to examine hypotheses. SE beliefs, explicit motives or implicit automatic associations with exercise did not differentiate inclined actors and abstainers. Coping SE was a significant predictor of being an inclined actor. Explicit weight management and appearance motives moderated the relationship between SE and becoming an inclined actor.
The purpose of Manuscript 3 was to examine how self-efficacy, explicit exercise motives and implicit automatic associations change over the course of a six-month exercise program as a function of exercise type (weight training or aerobic training). A total of 141 (aged 35-65) began the exercise program and were included in this manuscript. Repeated measures analysis of variance was used to assess change over time. Implicit associations did not change over time. Explicit motives, except weight management motives significantly decreased from baseline to six months and from three months to six months. The change in appearance motives was stronger for those in the strength-training group. Task, coping and scheduling SE increased from baseline and remained stable except for task SE, which, decreased from three to six months
