Funding for this research was provided by:
Velux Stiftung (project no. 917)
Seventh Framework Programme (no. 288940)
Text and Data Mining valid from 2019-07-24
Received: 12 April 2019
Accepted: 4 July 2019
First Online: 24 July 2019
Ethics approval and consent to participate
: All participants provided written informed consent and the Ethics Committee of the German Sport University Cologne had approved the study (relevant registration numbers: 5/2014, 38/2015, and 156/2017).
: The authors declare that they have no competing interests.