1. Research Assistant, Department of Public Health, Faculty of Health, Aarhus University, Denmark
2. Associate professor, Study director, Department of People and Technology, Roskilde University, Denmark
3. Professor, School of Sport and Health Sciences, University of Brighton, Brighton, United Kingdom
4. Professor, Department of Public Health, Faculty of Health, Aarhus University, Denmark and Department of Health and Nursing Science, Faculty of Health and Sport Sciences, Agder University Grimstad, Norway