FIGURE 1.

Change in the $\stackrel{.}{\text{V}}$O_2max value and its reproducibility in subjects divergent for fitness status using two different automated metabolic carts operated in breath-by-breath mode with different rolling breath-averages. (A) $\stackrel{.}{\text{V}}$O_2max response in a heterogeneous group of sedentary and physically active overweight and obese subjects ($\stackrel{.}{\text{V}}$O_2max range: 13–40 mL/kg/min) assessed with Vmax N29 Sensormedics (n = 51). (B) $\stackrel{.}{\text{V}}$O_2max response in a group of endurance-trained subjects ($\stackrel{.}{\text{V}}$O_2max range: 40–60 mL/kg/min) assessed with Vyntus CPX (n = 11). (C) $\stackrel{.}{\text{V}}$O_2max response in a group of recreationally active and endurance-trained subjects ($\stackrel{.}{\text{V}}$O_2max range: 35–60 mL/kg/min) performing one test with Vmax N29 and a duplicate test with Vyntus CPX in random order (n = 11). (D) $\stackrel{.}{\text{V}}$O_2max response assessed with the Vmax N29 and Vyntus metabolic carts in two groups of nine subjects each of similar $\stackrel{.}{\text{V}}$O_2max ($\stackrel{.}{\text{V}}$O_2max range: 40–60 mL/kg/min) (B). CV_f (%), coefficient of variation calculated as proposed by Forkman (2009). Note the clear trend for lower reproducibility and a larger decay of the $\stackrel{.}{\text{V}}$O_2max the lower the fitness of the subjects. Modified from Martin-Rincon et al. (2019) with kind permission.