Please use this identifier to cite or link to this item: http://hdl.handle.net/10553/6559
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dc.contributor.authorCalbet, José A.en_US
dc.contributor.authorBoushel, R.en_US
dc.contributor.authorRådegran, G.en_US
dc.contributor.authorSøndergaard, H.en_US
dc.contributor.authorSaltin, B.en_US
dc.contributor.otherCalbet, Jose A-
dc.date.accessioned2011-10-31T02:31:00Z-
dc.date.accessioned2018-03-08T13:11:46Z-
dc.date.available2011-10-31T12:16:27Z-
dc.date.available2018-03-08T13:11:46Z-
dc.date.issued2003en_US
dc.identifier.issn0363-6119en_US
dc.identifier.otherScopus-
dc.identifier.urihttp://hdl.handle.net/10553/6559-
dc.description.abstractTo unravel the mechanisms by which maximal oxygen uptake (VO2 max) is reduced with severe acute hypoxia in humans, nine Danish lowlanders performed incremental cycle ergometer exercise to exhaustion, while breathing room air (normoxia) or 10.5% O2 in N2 (hypoxia, approximately 5,300 m above sea level). With hypoxia, exercise PaO2 dropped to 31-34 mmHg and arterial O2 content (CaO2) was reduced by 35% (P < 0.001). Forty-one percent of the reduction in CaO2 was explained by the lower inspired O2 pressure (PiO2) in hypoxia, whereas the rest was due to the impairment of the pulmonary gas exchange, as reflected by the higher alveolar-arterial O2 difference in hypoxia (P < 0.05). Hypoxia caused a 47% decrease in VO2 max (a greater fall than accountable by reduced CaO2). Peak cardiac output decreased by 17% (P < 0.01), due to equal reductions in both peak heart rate and stroke VOlume (P < 0.05). Peak leg blood flow was also lower (by 22%, P < 0.01). Consequently, systemic and leg O2 delivery were reduced by 43 and 47%, respectively, with hypoxia (P < 0.001) correlating closely with VO2 max (r = 0.98, P < 0.001). Therefore, three main mechanisms account for the reduction of VO2 max in severe acute hypoxia: 1) reduction of PiO2, 2) impairment of pulmonary gas exchange, and 3) reduction of maximal cardiac output and peak leg blood flow, each explaining about one-third of the loss in VO2 max.en_US
dc.languageengen_US
dc.relation.ispartofAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiologyen_US
dc.sourceAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology [ISSN 0363-6119], v. 284 (2), p. R291-R303, (Febrero 2003)en_US
dc.subject241106 Fisiología del ejercicioen_US
dc.subject.otherHypoxiaen_US
dc.subject.otherCardiac Outputen_US
dc.subject.otherCardiovascular Physiologyen_US
dc.subject.otherFatigueen_US
dc.subject.otherPerformanceen_US
dc.titleDeterminants of maximal oxygen uptake in severe acute hypoxiaen_US
dc.typeinfo:eu-repo/semantics/Articleen_US
dc.typeArticleen_US
dc.identifier.doi10.1152/ajpregu.00155.2002en_US
dc.identifier.scopus0037306980-
dc.identifier.isi000180400700005-
dcterms.isPartOfAmerican Journal Of Physiology-Regulatory Integrative And Comparative Physiology-
dcterms.sourceAmerican Journal Of Physiology-Regulatory Integrative And Comparative Physiology[ISSN 0363-6119],v. 284 (2), p. R291-R303-
dc.contributor.authorscopusid7004323423-
dc.contributor.authorscopusid7003471688-
dc.contributor.authorscopusid6603717983-
dc.contributor.authorscopusid36958968500-
dc.contributor.authorscopusid7402963940-
dc.contributor.authorscopusid7103099936-
dc.identifier.crisid475-
dc.identifier.eissn1522-1490-
dc.description.lastpageR303en_US
dc.identifier.issue2 53-2-
dc.description.firstpageR291en_US
dc.relation.volume284en_US
dc.investigacionCiencias de la Saluden_US
dc.rights.accessrightsinfo:eu-repo/semantics/openAccess-
dc.type2Artículoen_US
dc.identifier.wosWOS:000180400700005-
dc.contributor.daisngid90295-
dc.contributor.daisngid220476-
dc.contributor.daisngid328369-
dc.contributor.daisngid1592176-
dc.contributor.daisngid8464-
dc.contributor.daisngid13919-
dc.contributor.daisngid21540315-
dc.identifier.investigatorRIDH-6693-2015-
dc.utils.revisionen_US
dc.contributor.wosstandardWOS:Calbet, JAL-
dc.contributor.wosstandardWOS:Boushel, R-
dc.contributor.wosstandardWOS:Radegran, G-
dc.contributor.wosstandardWOS:Sondergaard, H-
dc.contributor.wosstandardWOS:Wagner, PD-
dc.contributor.wosstandardWOS:Saltin, B-
dc.date.coverdateFebrero 2003en_US
dc.identifier.supplement475-
dc.identifier.supplement475-
dc.identifier.ulpgcen_US
dc.description.jcr3,627
dc.description.jcrqQ1
dc.description.scieSCIE
item.grantfulltextopen-
item.fulltextCon texto completo-
crisitem.author.deptGIR IUIBS: Rendimiento humano, ejercicio físico y salud-
crisitem.author.deptIU de Investigaciones Biomédicas y Sanitarias-
crisitem.author.deptDepartamento de Educación Física-
crisitem.author.orcid0000-0002-9215-6234-
crisitem.author.parentorgIU de Investigaciones Biomédicas y Sanitarias-
crisitem.author.fullNameLópez Calbet, José Antonio-
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