Objective: The aim of this study was to capture the impact of COVID-19 on exercise behavior in U.S. college students. Exercise behaviors and perceived academic stress were examined from pre-COVID-19 (January-March 2020) and early-COVID-19 (April-July 2020) to continued-COVID-19 times (August-October 2020). Participants: One hundred and thirty-two participants completed the online questionnaires retrospectively. Methods: Two-way analyses of variance were used to examine exercise behaviors and academic stress perception over time between genders. Results: Participants spent much time in sedentary behavior and an increase in academic stress was evident in learning during the early-COVID-19 period. The time spent in sedentary behavior was reduced, but the stress involving coursework remained during the continued-COVID period. The impact of the COVID pandemic was observed to be universal across sex groups. Conclusions: Universities should consider how to support physical and mental health during lockdown and extended closure due to a pandemic.