Objectives. This study examined whether stereotypes may predict health outcomes independently from their internalization into the self. Specifically, we tested whether endorsement of negative age stereotypes in the physical activity (PA) domain is related to decreased subjective vitality among active older adults, illustrating ego depletion. Method. This longitudinal study included 192 retired individuals aged 60–92 years who regularly participated in organized PA, and who completed the measures on three occasions (9-month period). Results. Multilevel growth models tested whether within-person variation in age stereotypes endorsement across waves predicted subjective vitality, after controlling for self-perceptions of aging and relevant covariates. Results showed that (a) within-person increases in endorsement of age stereotypes of self-efficacy (b = 0.17, p < .01) were associated with increases in subjective vitality, (b) betweenperson mean difference in endorsement of age stereotypes of PA benefits (b = 0.21, p < .05) positively predicted subjective vitality, and (c) subjective vitality mediated the relationship between endorsement of self-efficacy stereotype and self-rated health. Discussion. This study confirmed that endorsement of age stereotypes of PA predicted subjective vitality among active older adults. These results suggest that stereotypes may be related to health-related outcomes notably through ego depletion effects.