Received: 21 November 2018
Accepted: 29 August 2019
First Online: 24 September 2019
Ethics approval and consent to participate
: This study was approved by Qatar Anti-Doping Lab Ethics Committee (Doha, Qatar; approval no: E2017000215). All participants participated voluntarily and their personal information remained confidential.
: The consent to publish is not applicable.
: The authors declare that they have no competing interests.