1. Department of Physical Education, Volda University College, Postbox 500, 6101 Volda, Norway
2. Department of Health Promotion and Development, University of Bergen, Bergen, Norway
3. Division of Mental Health, Norwegian Institute of Public Health, Oslo, Norway
4. Department of Psychology, University of Oslo, Oslo, Norway
5. Department of Psychology, UiT The Arctic University of Norway, Tromsø, Norway