Objective: To examine the moderating effect of internalized media messages on ideal body shape and lifestyle in the relationships between physical exercise, self-esteem, physical self-perceptions, and body image satisfaction. Design: pre-test/posttest control group experimental design. Methods: 46 inactive women (mean age = 21.4 ± 2.1 years-old) volunteered to participate in this study and were randomly assigned to Exercise (n = 23) or Wait-list (n = 23) groups. The Exercise group participated in two 50 minutes long exercise sessions per week for six weeks. During this period women in the Wait-list group did not participate in any regular physical activity. The French version of the Physical Self-Perception Profile (ISP-25) and the Body Image Assessment Scale (BIAS-BD) were administered to participants before and after intervention. In addition, the Sociocultural Attitudes Toward Appearance Questionnaire (SATAQ) was completed to assess participants' level of internalization of media standards. Results and Discussion: Women in the Exercise group improved more in outcomes than those in the Wait-list group. Effects were only marginally moderated by levels of media internalization. Potential explanations for these findings are reviewed and discussed.