Comparative analysis of the effects of acute hypobaric hypoxia and atmospheric hypoxia on the human body

JI Yaoxuan; HUANG Zheng; XU Mohan; MAO Guoyun; LU Zhihong; WANG Yunying

doi:10.16289/j.cnki.1002-0837.2025.06003

Abstract：Objective To compare the effects of two hypoxia endurance tests and experiences on physiological functions and cognitive abilities,and to provide a reference for choosing appropriate hypoxia endurance training methods.Methods Seven male participants,mainly students of this school,with a mean age of 20.5 years,were subjected to acute high-altitude hypoxia via exposure to a hypobaric chamber and a hypoxic gas mixture.Data on blood oxygen saturation,heart rate,blood pressure,and neurological function were systematically collected.Results Both hypoxic exposures resulted in a decrease in oxygen saturation,a compensatory increase in heart rate and blood pressure,and a decline in cognitive ability.After 15 minutes of hypoxia at 3000 m,the blood oxygen saturation was stable at 90%,and the heart rate was stable at 80 times per minute;after 15 minutes of hypoxia at 5000 m,the blood oxygen saturation was stable at 80%,the heart rate of hypobaric hypoxia was stabilized at 90 times per minute,and the heart rate of normobaric hypoxia was stabilized at 85 times per minute.Blood pressure had a tendency to increase during hypoxia,but the change was not obvious.Hypoxia exposure at 3000 m had little effect on work ability,and the values of mental arithmetic,graph memory and curve matching ability decreased significantly after two hours of hypoxia(P<0.05);hypoxia exposure at 5000 m had greater effect on work ability,and the values of five neurological function tests decreased significantly after two hours of hypoxia(P<0.05).Conclusion Both types of hypoxic exposure led to decreased blood oxygen saturation and corresponding increases in heart rate and blood pressure as compensatory mechanisms.There were no significant differences in physiological and cognitive performance between normobaric hypoxia training and hypobaric hypoxia training.Each method possesses distinct advantages,and the appropriate approach can be selected based on the specific training environment to optimize the high-altitude physiological training for pilots.