Enhancement of preoxygenation for decompression sickness protection: effect of exercise duration.

Introduction: Since strenuous exercise for 10 min during preoxygenation was shown to provide better protection from decompression sickness (DCS) incidence than resting preoxygenation, a logical question was: would a longer period of strenuous exercise improve protection even further?

Hypothesis: Increased strenuous exercise duration during preoxygenation increases DCS protection.

Methods: There were 60 subjects, 30 men and 30 women, who were exposed to 9,144 m (4.3 psia) for 4 h while performing mild, upper body exercise.

Moderate exercise after altitude exposure fails to induce decompression sickness.

Introduction: The objective of this study was to determine the effect of exercise after altitude exposure (post-exposure exercise) on subsequent altitude decompression sickness (DCS) incidence. Existing USAF prohibition of exercise following altitude chamber training exposures and interest from operational personnel prompted our evaluation of post-exposure exercise as a DCS-inducing stressor.

Methods: After a 1-h resting preoxygenation, 67 subjects were exposed to 30,000 ft for 2-h while performing mild, upper body exercise.