Fig. 2.

A: grouped data of the eupneic end-tidal carbon dioxide ($\text{P}\text{E}{\text{T}}_{\text{C}{\text{O}}_2}$) under the two conditions, Oxy (oxygen) and room air. B: grouped data for the eupneic minute ventilation under the two conditions, Oxy and room air. There were no significant differences in either eupneic $\text{P}\text{E}{\text{T}}_{\text{C}{\text{O}}_2}$ or eupneic minute ventilation under the two conditions. Black and white bars represent room air and Oxy trials, respectively.