The phenomenon of maintenance of health-related physical activity is explored through an analysis of the underlying concepts and of the existing empirical evidence. The following targets were used for the analysis: (1) the concept of health-related physical activity, (2) the concept of maintenance, (3) common manifestations of maintenance in everyday living, (4) the promotional and behavioral characteristics of health-related physical activity, (5) the known determinants of free-living physical activity, and (6) intervention trials on physical activity in free-living groups. The analyses revealed the inherent resistance to adoption and maintenance of physical activity, particularly that of high-intensity and program-centered activities, the persistence, however, of many simple everyday routines and habits, the multiple determinants discovered for free-living physical activity and a few empirical demonstrations of the successful promotion of the maintenance of physical activity over a year or two. The promotion of the maintenance of health-related physical activity seems thus a distinct possibility provided that (1) the promotional situation is analyzed thoroughly, (2) the activity is chosen carefully with an emphasis on moderation in intensity and integration into the participant's life-style, (3) multiple promotional contacts are used, and (4) support from the participant's social and physical environment is provided. There is a need for more research on the maintenance of health-related physical activity using the stages of change models, behavior modification principles, self-control concepts, the concept of intrinsic motivation and the Relapse model. The method of analysis used here could apply to other health-related behaviors as well.