Funding for this research was provided by:
Bundesinstitut für Sportwissenschaft (072004/20)
Received: 18 February 2021
Accepted: 12 May 2021
First Online: 19 June 2021
: All procedures were in full compliance with the Declaration of Helsinki and approved by the ethical committee of the Carl von Ossietzky University Oldenburg in Germany (Reference: Drs.EK/2020/040). Informed consents were obtained prior to the interviews of this study.
: Not applicable.
: The authors, Irene R. Faber, Till Koopmann, Dirk Büsch, and Jörg Schorer, declare that they have no competing interests.