1. Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussel, Belgium
2. Faculty of Psychology and Educational Sciences, Vrije Universiteit Brussel, Brussel, Belgium
3. Departament de Psicologia Bàsica, Evolutiva i de l'Educació, Universitat Autónoma de Barcelona, Barcelona, Spain
4. Research Group for Sport Pedagogy, Windesheim University of Applied Sciences, Zwolle, the Netherlands
5. CONI Scuola dello Sport, Roma, Italy