Effects of preceding preparation in breath-hold divers: gas analysis in expired air and blood

Abstract

Expired gas composition and blood oxygen saturation were measured in professional breath-hold divers during 45s and unlimited apneas. Different preparation breathing techniques were executed before apneas to vary the severity and intensity of an apnea. The results show that oxygen consumption and carbon dioxide production in the expired air correlated with the duration of the apnea. Interestingly, the latter consumption and production related to the apnea duration decreased for longer apneas and for better preparation. In contrast, the consumption of oxygen in the blood increased for longer apneas but decreased for better preparation only.