Related Experiment Video
Updated: Jun 21, 2026

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
Sleep at simulated 2438 m: effects on oxygenation, sleep quality, and postsleep performance
J Michael Muhm1, T Leigh Signal, Paul B Rock
1The Boeing Company, P.O. Box 3707, MC 7H-90, Seattle, WA 98124-2207, USA. Mike.muhm@boeing.com
Introduction:
Crewmembers on ultra long-range commercial flights have the opportunity for rest and sleep in onboard areas in which the barometric pressure is 75.3 kPa (565 mmHg) or higher, equivalent to a terrestrial altitude of 2438 m (8000 ft) or lower. Sleep at higher altitudes is known to be disturbed, resulting in postsleep neurobehavioral performance decrements. We investigated the effects of sleep at 2438 m on oxygen saturation, heart rate, sleep quantity, sleep quality, postsleep neurobehavioral performance, and mood.
Methods:
Twenty men, 30-56 yr of age, participated in a blinded cross-over investigation conducted in a hypobaric chamber to compare the effects of sleep at altitude (ALT, 2438 m) and ground level (GND, 305 m).
Results:
SpO2 measured before sleep was significantly lower at ALT than at GND, 90.7 +/- 2.0% (average +/- SD) and 96.2 +/- 2.0%, respectively. During sleep, SpO2 decreased further to 86.1 +/- 2.0% at ALT, and 92.3% +/- 2.0% at GND. The percent of time during which SpO2 was below 90% was 44.4% (3.6-86.9%) at ALT and 0.1% (0.0-22.9%) at GND. Objective and subjective measurements of sleep quantity and quality did not differ significantly with altitude, nor did postsleep neurobehavioral performance or mood.
Discussion:
The absence of significant changes in sleep and post-sleep neurobehavioral performance associated with pronounced oxygen desaturation during sleep was unexpected. Further study is needed to determine if the same effects occur in women and to characterize the changes in respiratory physiology that occur during sleep at 2438 m in both sexes.
Related Concept Videos
Insufficient Sleep and Sleep Deprivation
Sleep deprivation is a more severe form of sleep loss...
Stages of Sleep
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
Substance Use Disorders Affecting Sleep
Understanding the concepts of physical dependence,...
Special considerations while measuring oxygen saturation
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is important.
Understanding Sleep
The circadian rhythm, a nearly 24-hour cycle, is deeply influenced by environmental light cues. Light exposure directly affects the hypothalamus, which in turn regulates...