Background and Objective The health benefits of regular exercise are well known, and the transition to adulthood is an important time for establishing exercise habits. In this study, we aimed to identify the degree of obesity prevention and fitness according to exercise level in male and female university students who live in dormitories. Material and Methods This study included 1,808 university dormitory residents, 1,263 men and 545 women, who completed a sociodemographic questionnaire and were classified into groups according to exercise habit. Sociodemographic data were expressed as frequency and percent, and one-way analysis of variance was conducted to examine the group difference according to exercise habit. Results Weight, muscle mass, lean body mass, and basal metabolism were significantly higher in male university students living in dormitories who habitually exercise at least 3 times a week compared to those who exercise less often (p<0.05). The body mass index was higher in female university students living in dormitories who exercise at least 3 times a week compared to those who exercise less often (p<0.05). The former group could also perform a greater number of sit-ups (p<0.01) and had greater back strength (p<0.01) and faster whole-body reaction time (p<0.01). Women who exercised at least once a week could perform more pushups versus those who did not exercise (p<0.01). Male university students living in dormitory who exercise at least 3 times a week had higher systolic blood pressure and greater grip strength than male students who exercised twice a week or less (p<0.05); they could also do more push-ups (p<0.05). Conclusion University students who exercise at least 3 times a week have somewhat higher fitness and healthier body composition compared to those who exercise twice a week or less. These differences may impact lifetime fitness and body composition.