平原人进驻海拔4370m高原后无氧阈的改变

本文观察了14名平原人进驻高原后气体交换无氧阈(AT_(GE))的改变。从中看到,达海拔4370m 高原后第3、5、7和14天,与到高原前比,AT_(GE)分别下降36.5%、32.4%、40.0%和39.0%(P<0.01),并十分接近在此海拔高度上最大氧耗量下降的经验值(34.0%)。平原人达高原后AT_(GE)下降的百分比与入高原前AT_(GE)呈正相关(r=0.851),P<0.01),在平原AT_(GE)较高者,达高原后AT_(GE)下降较多。还在同地观察了8名久居一年的平原人的AT_(GE),与平原对照值比,仍减少25.4%。上述结果表明,平原人进驻高原后,AT_(GE)明显下降,在短时间里尚不能恢复到平原时水平。AT_(GE)作为高原劳动能力评价指标是有应用意义的。

Change of Anaerobic Threshold after Arrival at 4370m Altitude From Sea level

A study was conducted in 14 young health normal sea level residentson the changes at physical work capacity during sojourn to high altitude.Initial studies oflow landers were carried out at ChengDu(approximately sea level).They were taken toan altitude of 4370 m by air and stayed there for 2 weeks.The subjects exercised on bi-cycle ergometer to volitional fatigue.After 5 min of unloaded cycling,the work rate wasincrcased by 20W every 3 min until exhaustion.During the exercise test,the subjects ex-pired into a Douglas bag during the final minute of each 3 min duration.The collectedexpired gas was immediately assessed for ventilatory gas exchange parameters((?)_E,(?)O_2,(?)_(co_2),(?)_E/(?)_(o_2),(?)_E/(?)_(co_2)).The scores of anaerobic threshold were determined by findingthe break point of the systematic increase in (?)_E/(?)_(o_2)during incremental exercise test(AT_(GE)).The results showed that on the 3th,5th,7th and 14th day after arrival at thealtitude of 4370m,the AT_(GE)decreased by 35.6%, 32.4%, 40.0% and 39.6%(p<0.01),respectively,in comparison with the value at sea level.They were close tothe experimental value of decreased maximal oxygen uptake(34%)at same altitude.Moreover,the reduction of AT_(GE)at high altitude tented to be greater in those with a larg-er initial AT_(GE)than in those with a small initial AT_(GE).It was still 24.5%(p<0. 01)lower than the sea level value even after one year residence at that altitude.These resultssuggested that after exposure to high altitude,AT_(GE)decreased markedly and would notreturn to sea level value after short period.In addition,AT_(GE)might be applicable to theevaluation of work capacity at high altitude.