Автор: Harald Graef

Rolf Kretschmann is currently a secondary school teacher at the Theodor-Heuss-Gymnasium, Hagen, in North Rhine-Westphalia, Germany, teaching Physical Education and Philosophy. He is a former Assistant Professor of Kinesiology and Director of Physical Education Teacher Education at the University of Texas, United States. His research focuses primarily on educational technology, health promotion and interventions, as well as evidence-based practices in physical education. At the time of this study's data collection and analysis, he was appointed “Wissenschaftlicher Mitarbeiter (Assistentur)” (equivalent to Assistant Professor) of Physical Education and Sport Pedagogy at the University of Stuttgart, Germany. Harald Graef is is currently a secondary school teacher at the Institut Montana, Zugerberg, in Zug, Switzerland, teaching Physical Education, English and German as Foreign Language (Gymnasium, International School). He is an ERCAcertified high ropes course and ISIA Level 3 skiing instructor. Jonas Holder is currently a secondary school teacher at the Theodor-Heuss-Gymnasium, Heilbronn, in Baden-Wuerttemberg, Germany, teaching Physical Education and English.