It is known that the practice of physical activity (PA) drops off drastically in late adolescence, during the transition to adulthood, leading to a deterioration in physical fitness among post-secondary students. Given the importance of the consequences of physical inactivity, interventions aimed at the sustained adoption of sufficient PA practice must be developed. The objective of this study is to evaluate the impact of a pedagogical strategy based on the question-behavior effect (QBE) implemented in the final post-secondary physical education and health (PEH) course and that capitalizes on the benefits derived from PA. An iterative, self-reflective exercise involving the personal benefits derived from PA practiced in PEH class was tested among 496 students (mean age: 19.10 [SD: 2.42]) from 15 post-secondary institutions and divided into three groups: self-reflection on benefits and on PA practiced (Group A; n = 152), self-reflection on PA practiced (Group B; n = 142), no self-reflection (Group C; n = 210). Two measurements of weekly PA practiced outside the school setting were taken: one week before the start of the final semester of PEH, and then six months after the end of that semester. In particular, the results indicate that PA practice outside of school increased among participants in Group A and that the proportion of students who were inactive at Time 1 who became active at Time 2 was higher in Group A. Thus, it appears that repeated awareness of the personal benefits of practicing PA in PEH class promotes engagement in PA done outside of class.