Conceptual physical education (CPE) courses play a critical role in promoting physical activity (PA) among students in American higher education settings. To date, however, very limited knowledge is available about the effectiveness of such courses. Aims: The primary purpose of the study was to examine effects of a CPE course on altering freshmen PA levels. The secondary objective was to test PA change differences in gender and major. Ninety-two freshmen from a large state university participated in the study. Daily steps and moderate to vigorous physical activity (MVPA) minutes were measured by accelerometers and were used to estimate freshmen's PA changes. Repeated measure MANOVA was conducted to analyze the PA differences in gender and major. The results revealed that students significantly reduced their PA levels from the pre-test to the post-test. The decline from the mid-test to the post-test, however, was not significant. Significant gender effect was also found. The CPE course helped freshmen slow down the PA decrease, even though the course did not significantly increase the students' PA. Such a course and had more positive effects on female student's PA than their male counterparts. Conclusion: The current study confirmed previously reported trend of PA decrease among freshmen. However, enrolling in a CPE might help minimize the decrease by allocating time within lab sections for PA and encouraging participation outside class, especially during the weekend when students tend to be more sedentary.