Text and Data Mining valid from 2020-03-05
Received: 25 July 2019
Accepted: 24 February 2020
First Online: 5 March 2020
Ethics approval and consent to participate
: The Human Ethics Committee at the University of Duisburg-Essen, Faculty for Educational Sciences approved the study protocol. Before experimental procedures began, participants’ assent and parents’ written informed consent were obtained.
: Not applicable.
: The authors declare that they have no competing interests. TM is an Editorial Board Member of BMC Sports Science, Medicine, and Rehabilitation.