Fig 3. Dependence of total oxygen consumption ($\dot{\mathbf{V}}{\mathbf{O}}_{\mathbf{2}}$), $\dot{\mathbf{V}}{\mathbf{O}}_{\mathbf{2}}$ related to proton leak, $\dot{\mathbf{V}}{\mathbf{O}}_{\mathbf{2}}$ related to ATP synthesis, Δp, NADH (% of total NAD) and phenomenological ATP/O₂ ratio on relative activity of ATP usage (relative rate constant, k_UT, or its activation in relation to rest, A_UT) in skeletal muscle for ‘standard’ proton leak activity.