Fig. 6.

V̇o_2max as a function of the lung diffusing capacity-cardiac output slope for each individual subject (from Fig. 2). A linear regression was fit to all data points for each measure. V̇o_2max is positively correlated with the DL_CO-Q̇ slope (A); V̇o_2max is not significantly correlated with the Dm_CO-Q̇ or Vc-Q̇ slopes(B and C). DL_CO, lung diffusing capacity for carbon monoxide; Dm_CO, alveolar-capillary membrane conductance; Vc, pulmonary-capillary blood volume. ●: Young Highly Fit (HF); ○: Young; ■: Old Highly Fit (HF); □: Old.