低氧训练中优秀女子中长跑运动员CK-MB和心电图∑T/R的变化

目的:探讨低氧训练对优秀女子中长跑运动员心功能的影响。方法:国家女子中长跑队运动员13人随机分为高住高练低训组(HiHiLo组,7人)和低住高练组(LoHi组,6人),两组在每天完成相同的日常平原训练计划的基础上,每周进行3次低氧训练,训练方式为蹬功率自行车,强度为个体80%VO2max,时间40分钟,氧浓度为14.7%左右(相当于海拔2800米高度)。此外,HiHiLo组晚上在低氧房居住10小时,房中空气氧含量为14.7%(相当于海拨2800米高度),LoHi组常氧居住,实验期4周。监测低氧训练前、低氧训练第1、2、3、4周的周一清晨心电图变化,读取心电图∑T/R值;同时取清晨空腹静脉血测定肌酸激酶同工酶CK-MB。结果:HiHiLo组在低氧训练过程中,CK-MB持续下降,低氧训练第1周、2周、3周、4周CK-MB均显著低于实验前(P<0.05),低氧训练第4周亦显著低于低氧训练第1周(P<0.05)。而LoHi组CK-MB则无显著变化。与低氧训练前相比,HiHiLo组和LoHi组心电图∑T/R的变化无显著差异。结果提示低氧训练对心脏功能无不良影响,低氧居住在某种程度上有利于心脏功能的恢复。

Effects of Hypoxic Training on CK-MB and ∑ T/R in ECG of Chineses Elite Female Middle and Long Distance Runners

Objective To investigate the effects of 4-week hypoxic training on cardiac function in elite female middle and long distance runners.Methods Thirteen national female middle and long distance runners were divided into HiHiLo group(n=7) and LoHi group(n=6) randomly.Both groups performed the daily training program every day and 3 times hypoxic training(at oxygen content 14.7%-simulate altitude of 2800m) at intensity of individual 80%VO_2max every week. HiHiLo group stayed in hypoxic chamber with oxygen content of 14.7% (simulate altitude of 2800m) for 10 hours every night, LoHi group lived in normal oxygen content of 21%,and trained for 4-week. CK-MB in blood serum and ∑T/R of ECG were measured. Results With the progression of hypoxic training, the value of CK-MB showed a decreasing tendency as compared with that before hypoxic exposure in HiHiLo group.It significantly decreased after 4-week hypoxic training. No significant change was found in LoHi group. Compared with that before hypoxic exposure,no significant change in ∑T/R was found in both groups.Conclusion The hypoxic training had no effect on cardiac function,whereas living in hypoxic condition facilitated the recovery of cardiac function after training.