The main purpose of this study was to explore the influence of social support and self-efficacy on the physical activity beliefs and behaviours of participants in a peer-mentoring intervention embedded in a community-based exercise program. A second purpose was to explore social support, self-efficacy, and perceived barriers and facilitators to exercise program adherence for study participants within the community-based exercise program setting. Participants (N=10, plus 6 mentors) were adults with chronic health conditions living in a low-income neighbourhood. Intervention (n=4) and comparison (n=6) groups completed self-report measures of physical activity, social support, and barrier self-efficacy at baseline, 6-weeks, and 12-weeks. Interviews were used post-intervention to explore the impact of peer mentoring, perceived social support and self-efficacy within the exercise setting, and barriers and facilitators to physical activity for study participants. Intervention participants showed greater exercise program adherence than comparison participants at 6-weeks. Qualitative findings suggest the peer mentoring intervention increased motivation and sense of obligation to adhere to the exercise program, and provided vicarious learning opportunities that may have indirectly influenced exercise program adherence for intervention and mentor participants. Findings also suggest that the exercise program was highly influential to participants’ social support and self-efficacy beliefs. Multiple barriers and facilitators to physical activity were reported. Overall, the current study supports the use of peer mentoring as an intervention strategy in combination with additional strategies to promote exercise program adherence in the study population. Practical implications are discussed in relation to the promotion of exercise program adherence in older adults with chronic health conditions participating in a community-based exercise program in a low-income neighbourhood. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2011-09-29 10:44:19.343