Fig. 6.

Wagner plots depicting peak regional muscle O₂ uptake as a function of convective O₂ delivery (curved lines) vs. tissue O₂ saturation (assumed to be analogous to mean capillary PO₂ for illustrative purposes) in the VLd (a), VLs (b), and RFs (c). Fick’s law of diffusion depicts $\dot{V}$O₂ peak as a function of tissue O₂ saturation with the slope (straight line) representative of muscle O₂ diffusive conductance. The intersection of these two lines determines the $\dot{V}$O₂ peak attained. Solid lines represent the upright position, dashed lines represent the supine position