The 210 Latinas were assigned at random to one of three groups: one six month physical activity intervention, one physical activity plus maintenance intervention, and one safety education control. Exercise training emphasized walking. Bilingual exercise leaders, aided by peer models from the community, used shaping procedures to establish daily walking in participants. In the maintenance program, family incentives reinforced transfer to community exercise and were used to establish positive feedback loops to promote activity within the family. Peer led community exercise sessions, and community activism were also used to establish social networks which reinforced sustained physical activity.