Effects Of Aerobic Exercise At High-Altitude On Physiological Acclimatization Levels Of Migrants

High altitude exposure can produce various adverse effects on the physiological system of plateau migrants,and the acclimation of the human body to changes in the external environment can effectively combat this adverse condition.For migrants who have been exposed to plateau for a long time,although they have successfully survived the plateau acclimation period,their physiological systems include:The cardiopulmonary function,red blood cell index,and sleep system are still weakened to a certain extent compared with plateau residents and native people,and there is a risk of plateau chronic diseases.Therefore,it is necessary to further improve the physiological acclimatization level of plateau migrants,and aerobic exercise has a certain improvement effect on various physiological systems of the human body,which is a potential effective method to promote plateau acclimatization.However,the effects of plateau exercise on the physiological system of migrants are rarely discussed in current studies.A randomized controlled trial was conducted to investigate the effects of long-term aerobic exercise on the physiological acclimatization level of lowland residents and its mechanism.Methods:A total of 121 lowland residents who had lived in the Tibetan plateau for more than two years were randomly divided into four groups.The low intensity（LI）,moderate intensity（MI）,and high intensity（HI）groups each performed 20 sessions of aerobic exercise over4 weeks,while the control（CG）group did not undergo any intervention.Repeated measures analysis of variance was used to compare the cardiopulmonary function,red blood cell index,renal function,immune function and sleep quality of participants in different groups before and after intervention.Furthermore,the structural equation model was used to explore the interaction between the changes of physiological systems by using the changes of physiological function before and after aerobic exercise intervention.Result:（1）There was no significant difference in the basic physiological indexes among the four groups before the experiment.The results showed that compared with CG,LI and MI intervention significantly improved cardiopulmonary function(maximum oxygen uptake:VO_2max,LI:p<0.001,MI:p<0.001)and immune function（total protein:TP,LI:p<0.001,MI:p<0.001;Globulin:GLB,LI:p<0.001,MI:p<0.001）.Meanwhile,the red blood cell index and renal function did not change significantly after exercise in the LI and MI groups.However,there were no significant changes in cardiopulmonary and immune functions in the HI group compared with the CG group.In contrast,red-cell related measures（red blood cell count:RBC,p<0.001）and renal burden（glomerular filtration rate:GFR,p<0.001）increased.Sleep quality also decreased significantly in all four groups.（2）The results of structural equation model showed that the changes of red blood cell index caused by high altitude exercise directly affected the changes of immune function（β=-0.317）.It also indirectly affected immune function through renal function（β=-0.104）,and exercise intensity moderated this relationship.Conclusion:Low and moderate intensity exercise,instead of high intensity exercise,can improve highland physiological acclimatization levels among lowlanders at Tibet by increase cardiopulmonary function and counteracting erythrocytosis.