Figure 3.

Mean values of differences in energy expenditure (EE; panel A), pulmonary ventilation (${\dot{\mathrm{V}}}_{\mathrm{E}}$; panel B), and heart rate (HR; panel C) between normoxia and hypoxia at rest and each walking speed between men and women. Changes in ΔEE versus in Δ${\dot{\mathrm{V}}}_{\mathrm{E}}$ (panel D), and changes in ΔEE versus in ΔHR (panel E), and changes in ΔHR and Δ${\dot{\mathrm{V}}}_{\mathrm{E}}$ (panel F) between men and women. Ordinary least squares linear regression equation, with an intercept = 0 are shown for between ΔEE and Δ${\dot{\mathrm{V}}}_{\mathrm{E}}$. Second- order polynomial regression equation, with an intercept = 0 are shown for between ΔEE and ΔHR, and between Δ${\dot{\mathrm{V}}}_{\mathrm{E}}$ and ΔHR. Each symbol are the same as in Fig. 1. Solid lines indicate for men and dashed lines indicate for women. The number of 0.0 on the X axis indicate at rest.