Background: A healthy body image is related to better psychological well-being and can also impact one’s likelihood to engage in health promoting behaviours such as exercise. To date, there has been a paucity of research investigating the relationship between body image and Self-Determination Theory’s motivational regulations as a function of exercise participation. The purpose of this study was to examine these constructs over the course of an 18-week cardiovascular-based program for female initiates aged 18-45 with overweight and obesity. Material/Methods: Participants (n = 37; mean weight = 83.8 kg; mean waist circumference = 38.3 inches) were provided with a personalized exercise program and asked to complete the Multidimensional Body-Self Relations Questionnaire and the Behavioural Regulations in Exercise Questionnaire-2 at four different time-points (i.e., baseline and every six weeks). Results: Significant improvements to body image constructs were observed over time indicating that feelings of satisfaction with aspects of appearance, as well as physical attractiveness were enhanced (e.g., Appearance Evaluation, p<0.001, η2 = 0.59). Participants also felt increasingly invested in being physically fit up to week 12 of the program (e.g., Fitness Orientation, p<0.01, η2= 0.19). Significant relationships were observed between appearance-related body image and the more self-determined forms of exercise motivation (e.g., Body Areas Satisfaction and Intrinsic Regulation, r= 0.50, p= 0.001). Conclusions: Implications of focusing on these variables within physical activity interventions are discussed and underscore the important role that body satisfaction plays with respect to exercise motivation in this particular population.