Changes of heart rate and heart rate variability of parachutists during simulated parachute descent in wind tunnel
CHEN Xiangning
XU Wenchao
YU Zhibin
CHENG Jiuhua
ZHANG Lin
Abstract：Objective To compare the differences of heart rate and heart rate variability(HRV)between the parachutists at rest and in the wind tunnel,and to explore the changes of psychological stress and cardiovascular autonomic regulation in the parachutists during parachute descent.Methods Eight young male parachutists were chosen and the process of parachute descent was simulated by wind tunnel experiment.Before the experiment,the parachute cold-weather survival suit and physiological parameter recording detector were worn,and the ECG signal was continuously recorded in the ground resting state.The experiment was carried out in the wind tunnel for at least 10 min,and the ECG signal was continuously dynamically recorded until the end of the experiment.Two states of ECG steady signals were selected for 5 min each.Paired t-test was used to analyze the differences of heart rate,blood oxygen saturation(SpO2)and HRV under these two states,as well as the changes of body temperature of parachutists at the beginning of the experiment and 15 min after the experiment.Results Compared with the ground resting state,the heart rate during blowing in the wind tunnel was significantly increased(P＜0.01),SpO2 was significantly decreased(P＜0.01),and the body temperature was significantly increased 15 min after the experiment(P＜0.01).The time domain related indexes of HRV,including RR interval,average RR,median RR,standard deviation of NN intervals,coefficient of variation of R-R intervals,standard deviation of differences between adjacent NN intervals,root mean square of successive differences and percentage of RR intervals that differ by 50 ms were all significantly decreased(P＜0.01,P＜0.05).The frequency domain related indexes of very low frequency power and low frequency power(LF)were significantly decreased(P＜0.05),while high frequency power(HF)showed no significant change(P=0.060 9),and LF/HF was significantly increased(P＜0.05).Conclusion The stress level,heart rate and HRV of the parachutists increase during parachute descent.Parachute descent has an impact on stress regulation of the cardiovascular autonomic nervous system,and autonomic nervous function develops towards the dominance of sympathetic nervous system.
Keywords：wind tunnel experimentheart rateheart rate variabilitystress
Publication Date：2025-01-27
Online Publishing Date：2026-08-26(First online date of this platform, not the publication date of the document)