What are groups all about--Basic principles of group work for health-related physical activity

The basic group processes such as norms, roles, social support, and the developmental phases of a group are defined and applied to physical activity groups. Three kinds of groups are differentiated for the promotion of health-related physical activity: on-the-spot information in groups, traditional physical activity groups, and interactive promotional groups. The case is forwarded that in the promotion of physical activity group work is most effective, if it is based on mutual interaction between the group members and utilizes group processes. Arguments are presented for the advantage of interactive promotional groups to help people adopt health-related physical activities.