Fig. 1

Time course of study and changes of LLS and physiological parameters. A The X axis shows the times after departing from Fujinomiya city at 120 m. The Y axis shows the altitude. B In this study, AMS was defined as a LLS ≥ 3 with headache after sleeping at 3775 m. Dotted line indicates LLS of 3. C Change in SpO₂, HR, sBP, dBP and MAP. All values are expressed as the mean ± SD. D SpO₂, HR, CI and SVI values of the AMS and non-AMS subjects at 120 m and 3775 m. #Indicates a statistically significant difference between the AMS and non-AMS subjects (p < 0.05). E The ΔSpO₂, ΔHR, ΔCI and ΔSVI values of the AMS and non-AMS subjects at 120 m and 3775 m. #Indicates a statistically significant difference between the AMS and non-AMS subjects (p < 0.05). All values are expressed as the mean ± SD. AMS acute mountain sickness, CI cardiac index, dBP Diastolic blood pressure, HR heart rate, LLS Lake Louise Score, MAP Mean arterial pressure, MFRS Mt. Fuji Research Station, sBP Systolic blood pressure, SD standard deviation, SVI stroke volume index