Hypoxic Gas Mixture Simulation for Altitude Training

The hypoxic gas mixture for the trials was created by the Biomedtech GO2Altitude ERA II Hypoxic/Hyperoxic Air Generator (Australia). The manufacturer’s recommendations were followed in order to reduce the oxygen concentration of the inspiratory gas mixture to replicate height above sea level (a.s.l.), as stated in the GO2Altitude ERA II Hypoxicator System Operational Manual (Biomedtech Australia Pty Ltd., Biomedical Research and Development). The FIO₂ = 13% oxygen level in the mixture was utilized to construct a hypoxic mix that accurately reflected altitude at 3500 m a.s.l.. Participants were not aware of the gas mixture but were breathing normally. They also wore pulse oximeters and donned masks when doing testing in normoxia, even though the air generator at the time only delivered a sea level breathing mixture [33 (link)].