This study examined predictors of obligatory exercise in college undergraduates ("N"= 172). Regression models indicated that internalization of Western attitudes toward appearance predicted exercise fixation and commitment in women, whereas perceived pressure from dating partners predicted exercise commitment in men. Findings suggest that men may respond more to peer pressure, whereas women may be more susceptible to internalized sociocultural pressure. Implications for differential assessment and treatment of college men and women are discussed. (Contains 3 tables.)