[abstract] MAXIMAL OXYGEN UPTAKE DURING NORMOXIC AND HYPEROXIC HELIUM BREATHING AT 18.6 ATA.

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[abstract] MAXIMAL OXYGEN UPTAKE DURING NORMOXIC AND HYPEROXIC HELIUM BREATHING AT 18.6 ATA.

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Title: [abstract] MAXIMAL OXYGEN UPTAKE DURING NORMOXIC AND HYPEROXIC HELIUM BREATHING AT 18.6 ATA.
Author: Dressendorfer, RH; Hong, SK; Morlock, JF; Pegg, J; Respicio, B; Smith, RM; Yelverton, C
Abstract: Submaximal and maximal cardiorespiratory responses of four men to cycling exercise were observed during 17 days at 18.6 ATA. Inspired gas at pressure consisted of hyperoxic (P02 = 232 mmHg) and normoxic (P02 = 159 mmHg) helium mixtures with relative gas densities of 3.8 and 2.8, respectively. Postdive Vo2max (1 ATA, air) did not differ significantly from the predive value and averaged 3.10 l.min-l . During 5 min of submaximal exercise at 50% of V02max no significant difference in work rate, V02, VC02' VE, respiratory rate, heart rate (HR), stroke volume, blood pressures, and rectal temperature was noted at 18.6 ATA with either gas mixture. Submaximal HR tended to decrease by 5 to 10 bpm at pressure and in hyperoxia. Maximal exercise was performed to exhaustion at work rates requiring about 120% of Vo2max. Significant increases in Vo2max of 0.10 l.min-l (3%) and in endurance time of 2 min (48%) were found during hyperoxic gas breathing at 18.6 ATA, whereas normoxic values were similar to 1 ATA. Significant reductions in peak HR of 8 bpm (4%) were observed with both gas mixtures at pressure and YE was significantly decreased by 36 l.min-l (26%) in hyperoxia and 29 l.min-l in normoxia. No change was found in the calculated cardiac output. The results indicate that aerobic power and endurance performance were affected by oxygen pressure. Normoxic work capacity, however, was not decreased at 18.6 ATA despite marked reductions in HR and YE' (This research was supported by ONR Contracts N00014-75-C-0404 and N00014-67-A-0387-00l6 with funds provided by the Naval Medical Branch and Development Command, NOAA Sea Grant 04-3-158-29, and State of Hawaii MAC's Office Task Order MT-001.)
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held May 12-13, 1976. Carillon Hotel, Miami Beach, FL (http:www.uhms.org)
URI: http://archive.rubicon-foundation.org/5255
Date: 1976

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  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

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