1. Department of Medical Psychology and Medical Sociology, Faculty of Medicine Ruhr University of Bochum Bochum Germany
2. Unit of Sport Psychology Ruhr University of Bochum Bochum Germany
3. School of Human Movement and Nutrition Sciences The University of Queensland Brisbane Queensland Australia
4. Department of Health and Social Psychology German Sport University Cologne Cologne Germany
5. Faculty of Health Science Southern University of Denmark Odense Denmark