Bioethical approval & trial registration
POLAND
The study was approved by the Research Bioethics Committee of the Academy of Physical Education in Katowice (Mikolowska 72a Street, 40-065 Katowice, Poland) under the reference number 3/2020 on 17 December 2020. Informed consent was obtained from all subjects involved in the study. The trial is registered under the number: ISRCTN41899475; (10.1186/ISRCTN41899475).