Figure 1.

(A) Percentage improvement in $\stackrel{.}{\mathrm{V}}$O_2max prediction accuracy in the BMI model^HR0, BMI model^{∆HR3 − HR4}, PBF model^BC, PBF model^HR0, and PBF model^{∆HR3 − HR4} as compared with the BMI model^BC. (B) Percentage improvement of $\stackrel{.}{\mathrm{V}}$O_2max prediction accuracy in PBF model^HR0 and PBF model^∆HR3−HR4 as compared with the PBF model^BC.