Physiological measures related to the cardiorespiratory system were collected during rest and exercise for SaO2, VE, HR, RR, oxygen uptake (VO2), VT and blood pressure (BP). Additionally, the Borg Rating of Perceived Exertion Scale (RPE) was used to track self-rated physical exertion (scale of 6-20) and the modified Borg Rating of Perceived Dyspnea was used to track self-reported breathlessness (scale of 1-4)
For this investigation, an MC-TA-200V Metabolic Cart was used to collect pulmonary spirometry data while the subjects performed their exercise on a Monark 828E cycle ergometer. A Hypoxico HYP123 hypoxic generator was used in conjunction with a Douglas Bag to create an FiO2 of 13.8% and a PO2 of 101 mmHg compared to the fraction of inspired O2 (FiO2) measured at 20.8% and a PO2 of 151 mmHg in the testing laboratory. To measure air composition for O2 and CO2 levels (FiO2/FiCO2) a Quantek Instruments Model 902D O2/CO2 Headspace Analyzer was used. Additionally, a Choice Med MD300 C2 pulse oximeter was used to measure SaO2, a 3M Litman Classic II SE stethoscope in combination with a Mabis Aneroid sphygmomanometer were used to collect the subjects’ BP and a Polar FT1 heart rate monitor and telemetry strap combination were used to collect HR