O2 extraction maintains O2 uptake during submaximal exercise with beta-adrenergic block-ade at 4300 m. - Wolfel,E.E.; Selland,M.A.; Cymerman,A.; Brooks,G.A.; Butterfield,G.E.; Mazzeo,R.S.; Groover,R.F.; Reeves,J.T. (J Appl Physiol, 1998)