Purpose: The purpose of this study was to examine if automatic enrollment in exercise-promoting courses on a college campus, with a choice to opt out, would increase enrollment. Method: In a simulated course selection paradigm, 317 college students were randomly assigned to one of three conditions: optimal default (automatic enrollment in an active physical education well-being course with the choice to opt out to a sedentary alternative), suboptimal default (automatic enrollment in a sedentary well-being course with the option to select an alternative active physical education courses), or free choice. Data were analyzed using logistic regression. Results: Participants in the optimal default condition were significantly more likely to enroll in an active physical education well-being course compared with those in the suboptimal-default and free-choice conditions. Discussion/Conclusions: Setting optimal physical education course defaults in the college environment can promote student health by increasing the likelihood of enrolling in exercise-promoting courses.