Purpose: To explore changes in daily activities associated with high-intensity volunteering, this study assessed activities in a sample of 180 new Experience Corps (EC) volunteers serving low reading students in urban schools. Methods: Level of activity in 15 areas (visiting friends, reading, watching TV, etc.) was obtained at the beginning of this high-commitment volunteer experience and after 9 months of service. Latent class analyses were used to identify activity patterns, and regression analyses were used to identify factors associated with changes in activities. Results: At pre-test, 37% were classified in the low-activity group and were more likely to be first time volunteers, older, non-White, and have less education. At post-test, only 17% were classified as low activity. An increase in activity was more likely to occur for those who were low activity before joining the volunteer program. Implications: These findings demonstrate that increase in activity does occur for less active older adults who join a volunteer program.