Funding for this research was provided by:
Grantová Agentura České Republiky (18-09188S)
Received: 21 September 2021
Accepted: 8 December 2021
First Online: 4 January 2022
: The study was approved under reference number 53/2012 on 18 December 2012 (updated on 16 March 2017 under reference number 19/2017) by the Ethics Committee of the Faculty of Physical Culture, Palacký University Olomouc, which is governed by the ethical standards set out in the World Medical Association Declaration of Helsinki and its later amendments. Prior to the implementation of the research the participants’ parents or guardians signed a written informed consent form.
: Not applicable.
: The authors declare that they have no competing interests.