Feasibility of predicting maximal oxygen uptake by using the efficiency factor in healthy men

Figure 1. Scatter plot of independent variables of the derivative group and the measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max (n = 105). BMI, PBF, HRR, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max represent body mass index, percent body fat, heart rate reserve, and maximal oxygen uptake, respectively. EF1, EF2, EF3, EF4, EF5, EF6 and EF7 represent different levels of efficiency factors from stages 1 to 7 during the CPET.

Figure 2. (A) Compared to that of the BMI model, the percentage change of PBF modelHRR, PBF modelEF6, and PBF modelEF7 in R2, SEE, and %SEE; (B) Compared to that of the PBF modelHRR, the percentage change of the PBF modelEF6 and PBF modelEF7 in R2, SEE, and %SEE. PBF percent body fat, HRR heart rate reserve, EF6 efficiency factor of stage 6 during the CPET, EF7 efficiency factor of stage 7 during the CPET, R2 multiple coefficients of determination, SEE standard error of estimate, %SEE SEE/mean of measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max × 100.

Figure 3. The association between the measured and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max: (A) BMI model; (B) PBF modelHRR model; (C) PBF modelEF6; and (D) PBF modelEF7. BMI, body mass index; PBF, percent body fat; HRR, heart rate reserve; EF6, efficiency factor of stage 6 during the CPET; EF7, efficiency factor of stage 7 during the CPET; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max maximal oxygen uptake.

Figure 4. The difference between the measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max predicted by the BMI model (A), PBF modelHRR model (B), PBF modelEF6 (C), and PBF modelEF7 (D) in Bland‒Altman plots. BMI body mass index, PBF percent body fat, HRR heart rate reserve, EF6 efficiency factor of stage 6 during the CPET, EF7 efficiency factor of stage 7 during the CPET, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot{\text{V}}\text{O}}_{2\max }$$\end{document}V˙O2max maximal…