1University of Zagreb Faculty of Kinesiology, Zagreb, Croatia 2Faculty of Science and Education University of Mostar, Department for Kinesiology, Mostar, Bosnia and Herzegovina DOI 10.7717/peerj.19686 Academic Editor Davor Plavec Subject Areas Anatomy and Physiology, Sports Medicine Keywords Gas exchange, Method comparison study, Rectal temperature, Treadmill running, Ventilatory threshold Copyright © Licence This is an open access article distributed under the terms of the Creative Commons...