BACKGROUND: Vigorous physical activity (VPA) declines from adolescence into adulthood, and social disparities in VPA exist. Physical activity is understudied in the college setting. METHODS: VPA during high school and college was examined among 10,437 students attending 119 four-year colleges using gender-stratified logistic regression analyses. RESULTS: Fewer students engaged in VPA in college compared with high school (males 74% to 52%; females 68% to 44%). Athletics was associated with VPA, but 51% participated in high school and 15% in college. Among females, African Americans, Asians, and students of lower socioeconomic position (SEP) were less likely to engage in VPA in college, adjusting for high school VPA. Among males, Asians and older students were less likely to engage in VPA. CONCLUSIONS: VPA declines from high school to college. Athletic participation is a determinant of VPA, but few participate in collegiate athletics. Social disparities in VPA emerge in college, an important setting for promoting VPA and addressing health disparities.