Sedentary living is a serious global public health problem that is associated with numerous preventable diseases. Schools are in a position to be the most cost-effective public resource to combat inactivity. In schools physical educators are positioned to be the strongest advocates of a healthy, active lifestyle. To effectively promote physical activity on school campuses and to encourage it in communities beyond the school day, physical educators will need to develop skills that are not typically stressed in undergraduate physical education teacher education (PETE) programs. As a result, both undergraduate PETE and in-service staff-development programs will need to be revised if schools are to play a major role in physical activity promotion.