AUTHOR=Su Rui , Peng Ping , Zhang Wenrui , Huang Jie , Fan Jing , Zhang Delong , He Jiayuan , Ma Hailin , Li Hao 

TITLE=Dose-effect of exercise intervention on heart rate variability of acclimatized young male lowlanders at 3,680 m

JOURNAL=Frontiers in Physiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1331693

DOI=10.3389/fphys.2024.1331693

ISSN=1664-042X

ABSTRACT=<p>This study investigated whether exercise could improve the reduced HRV in an environment of high altitude. A total of 97 young, healthy male lowlanders living at 3,680 m for &gt;1 year were recruited. They were randomized into four groups, of which three performed—low-, moderate-, and high-intensity (LI, MI, HI) aerobic exercise for 4 weeks, respectively. The remaining was the control group (CG) receiving no intervention. For HI, compared to other groups, heart rate (<italic>p</italic> = 0.002) was significantly decreased, while standard deviation of RR intervals (<italic>p</italic> &lt; 0.001), SD2 of Poincaré plot (<italic>p</italic> = 0.046) and the number of successive RR interval pairs that differ by &gt; 50 ms divided by total number of RR (<italic>p</italic> = 0.032), were significantly increased after intervention. For MI, significantly increase of trigonometric interpolation in NN interval (<italic>p</italic> = 0.016) was observed after exercise. Further, a decrease in systolic blood pressure (SBP) after high-intensity exercise was found significantly associated with an increase in SD2 (<italic>r</italic> = – 0.428, <italic>p</italic> = 0.042). These results indicated that there was a dose effect of different intensities of aerobic exercise on the HRV of acclimatized lowlanders. Moderate and high-intensity aerobic exercise would change the status of the autonomic nervous system (ANS) and decrease the blood pressure of acclimatized lowlanders exposed to high altitude.</p>