Text and Data Mining valid from 2019-12-01
Received: 6 May 2019
Accepted: 1 November 2019
First Online: 27 December 2019
Ethics approval and consent to participate
: The protocol of the study was approved by the Research Ethics Committee, University of Physical Education, Warsaw, Poland (SKE 01–14/2014), prior to the enrolment of the participants. We obtained written consents from all individual participants included in the study who also received an information sheet detailing what the study involved.
: Not applicable.
: The authors declare that they have no competing interests.