Fig. 2.

Measures of arterial oxygen saturation ($\text{S}{\text{a}}_{{\text{O}}_2}$; A), arterial oxygen content ($\text{C}{\text{a}}_{\text{O}}{}_{{}_2}$; B), arterial partial pressure of oxygen ($\text{P}{\text{a}}_{\text{O}}{}_{{}_2}$; C) and carbon dioxide ($\text{P}{\text{a}}_{\text{C}\text{O}}{}_{{}_2}$; D), and estimates of oxygen delivery (E) and regional tissue saturation (r-So₂; F) while stationary on a cycle ergometer and during submaximal exercise under normoxic (${\text{F}\mathrm{I}}_{{\text{O}}_{\text{2}}}$ = 0.21, closed circles) and hypoxic (${\text{F}\mathrm{I}}_{{\text{O}}_{\text{2}}}$ = 0.125, open circles) conditions. *Significantly different from normoxia.