1. Department of Epidemiology and Health Promotion, National Public Health Institute, Helsinki, Finland
2. Department of Public Health, University of Helsinki, Helsinki, Finland
3. Department of Public Health and General Practice, University of Kuopio, Kuopio, Finland
4. Department of Physiology, University of Kuopio, Kuopio, Finland
5. Kuopio Research Institute of Exercise Medicine, Kuopio, Finland