SL = Sea Level HA1 = High Altitude Day 1 HA3 = High Altitude Day 3 Psys(av) = Systolic Blood Pressure (Average) Pdia(av) = Diastolic Blood Pressure (Average) SpO2 (%) = Oxygen Saturation (Percent) HR (bpm) = Heart Rate (beats per minute) CO (%) = Carbon Monoxide (Percent) CO (ppm) = Carbon Monoxide (Parts Per Million) Hct (av) = Hematocrit (average) AMS Total Score = Acute Mountain Sickness Total Score padj = Adjusted P.Value BY.p.value = Adjusted P.value