高原适应进程中LTHR及SaO_(2)变化规律--不同高原适应时相人群的Conconi运动证据

Changes of Lthr and SaO_(2) in the Process of High Altitude Adaptation:Evidence of Conconi Exercise in Different High Altitude Adaptation Phases

目的:评价世居高原、世居亚高原及不同移居高原时相人群的乳酸阈心率及SaO_(2)变化规律,为研究高原环境下人体运动反应提供依据。方法:以50名世居高原地区、50名世居亚平原及62名不同移居高原时相的20∼40岁青年男性为研究对象,采用改良后Conconi运动试验测试受试者乳酸阈心率及SaO_(2)水平。结果:随运动负荷上升,各组受试者心率、血乳酸均呈上升趋势,世居高原及亚高原受试者运动心率普遍低于移居高原受试者。在低负荷阶段(负荷1、负荷2),各测试组运动心率差异明显低于中高负荷阶段,负荷3以后各组“心率差异”特征愈加明显,各组差异在负荷3及负荷4最高,负荷5以后“心率差异”现象逐渐消除。同时,HA1组“乳酸拐点”出现时间最早,HA2组在负荷3出现,HA3组、RHA组在负荷4出现,RSHA组出现时间最晚,可见受试者“乳酸拐点”出现时间分布特征与“心率拐点”存在一定差异,即“乳酸拐点”的出现时间可能总体早于“心率拐点”。RSHA组乳酸阈水平显著高于HA1组(P<0.05),RHA组高于高原适应组受试者,但组间比较不存在显著差异(P>0.05),HA3组、RHA组及RSHA组乳酸阈跑速显著高于HA1组(P<0.05)。RSHA组、RHA组及HA3组受试者SaO_(2)水平在安静状态、各级运动负荷即刻均不存在显著差异,且HA3组SaO_(2)变化轨迹与RHA组基本一致。结论:随着高原适应时间延长,移居高原人群的运动反应特征逐渐向世居高原人群演进。

Objective:To evaluate the changes of lactate threshold heart rate and SaO_(2) in people living in pla⁃teau,sub-plateau and different periods of migration to plateau,so as to provide the basis for the study of human motion response in plateau environment.Methods:50 young men aged 20∼40 years old living in plateau area,50 in sub-plateau area and 62 in different periods of immigrating to plateau were selected as the subjects.The lactate threshold heart rate and SaO_(2) level of the subjects were measured by modified Conconi exercise test.Re⁃sults:With the increase of exercise load,the heart rate and blood lactic acid of the subjects in each group showed an upward trend,and the exercise heart rate of the subjects living in the plateau and sub-plateau was generally lower than that of the subjects immigrating to the plateau.In the low load stage(load 1,load 2),the heart rate difference of each test group was significantly lower than that in the medium and high load stage.After load 3,the characteristics of"heart rate difference"in each group were more obvious.The differences of each group were the highest in load 3 and load 4,and the phenomenon of"heart rate difference"gradually disap⁃peared after load 5.At the same time,the"lactic acid inflection point"appeared the earliest in HA1 group,ap⁃peared in HA2 group at load 3,appeared in HA3 group and RHA group at load 4,and appeared the latest in RSHA group.It can be seen that there is a certain difference between the"lactic acid inflection point"and the"heart rate inflection point",that is,the"lactic acid inflection point"may appear earlier than the"heart rate in⁃flection point".The lactate threshold level of RSHA group was significantly higher than that of HA1 group(P<0.05),and that of RHA group was higher than that of high altitude adaptation group,but there was no significant difference between groups(P>0.05).The lactate threshold running speed of HA3 group,RHA group and RSHA group was significantly higher than that of HA1 group(P<0.05).There was no significant difference in SaO_(2) level between RSHA group,RHA group and HA3 group at rest and at the moment of exercise load,and the trajectory of SaO_(2) change in HA3 group was basically the same as that in RHA group.Conclusion:with the extension of al⁃titude adaptation time,the characteristics of motor response of the people who migrated to the plateau gradually evolved to those who lived in the plateau.