Figure 5.

Receiver operating characteristic curves for maximum oxygen consumption measured by the cardiopulmonary exercise test (blue solid line), estimated maximum oxygen consumption by the smartwatch test (green solid line), and red blood cell distribution width-coefficient of variation (red solid line), and for Model 1 (blue dotted line: combination of maximum oxygen consumption measured by cardiopulmonary exercise test and red blood cell distribution width-coefficient of variation) and Model 2 (green dotted line: combination of estimated maximum oxygen consumption by smartwatch test and red blood cell distribution width-coefficient of variation) in predicting acute mountain sickness. VO₂max-CPET: maximum oxygen consumption measured by cardiopulmonary exercise test; VO₂max-SWT: estimated maximum oxygen consumption by smartwatch test; RDW-CV: red blood cell distribution width-coefficient of variation.