Fig. 4.

Steady-state rates of exercising P_i→ATP flux and its increment above basal levels, compared with measures of oxidative ATP synthesis rates. Exercising steady-state rates of P_i→ATP flux (V_Pi-ATP) (A) and its increment above basal levels (B), plotted against oxidative ATP synthesis rates (V_ATP) as measured from the immediate end-of-exercise PCr resynthesis rate. Black stars represent individuals in group A, and multiple scans of the three volunteers in group B are denoted by circles of black, gray, and white, respectively. The solid line represents unity equivalence of the two rates.