人工重力联合有氧锻炼可以有效对抗4d头低位卧床所致立位耐力不良

Ergometric Exercise Combined with 2 G Artificial Gravity to Be Useful as Efficious Countermeasure Against Orthostatic Intolerance after 4 Day Head-down Bed Rest

目的探讨人工重力联合运动锻炼对模拟失重引起的心血管功能失调的对抗效果。方法12名男性志愿者随机分为对照组和锻炼组。对照组仅进行4天头低位卧床，锻炼组在卧床期间每天进行60min的2G人工重力联合80％～95％无氧阈强度的有氧锻炼。卧床前后测量立位耐力、运动能力、心脏收缩功能、血浆容量、胭静脉顺应性等。结果与卧床前相比，对照组卧床后立位耐力、运动耐力及心脏泵血与收缩功能明显下降（P〈0．05），胭静脉横截面积及顺应性显著增加（P〈0．05），而锻炼组志愿者卧床后上述参数无明显变化。结论4d头低位卧床可导致心脏收缩功能降低，血浆容量减少以及下肢静脉顺应性升高，立位耐力及运动耐力下降。每天60rain的2G人工重力联合80％-95％无氧阈运动强度的锻炼可有效维持卧床期间心脏收缩功能、血浆容量以及下肢静脉顺应性，从而对抗模拟失重引起的立位耐力和运动耐力的下降。

Objective 1o investigate wlaetlaer the ergomemc exercise comomeu with 2G artificial gravity benefitfor countermeasures effiiciency on cardiovascular function dislocation during 4 days of simulated weightless- ness. Methods Twelve healthy volunteers were divided randomly to groups of control （Con） and aerobic exercise （Ex）. The volunteers in group of Con performed 4 days of -6° head-down bed rest （HDBR） without any intervention, and the Ex group received daily 60 min ergometric aerobic （80% -95% anaerobic threshold intensity） exercise combined with 2 G artificial gravity during the HDBR. Orthostatic tolerance, cardiac systol- ic function, plasma volume and compliance of popliteal vein were measured before and after HDBR. Results Compared with pre-HDBR, orthostatic tolerance and cardiac systolic function in control group decreased signif- icantly after HDBR （P 〈 0.05 ）, and cross-section area and venous compliance of popliteal vein increased sig- nificantly （P 〈 0.05）. While these viable indexes in group Ex was unchanged throughout the HDBR （P 〉 O. 05 ）. Conclusion 4 days HDBR induced significant decrease in cardiac systolic function and orthostatic tol- erance, exercise capacity, plasma volume and increase in venous compliance. Daily 60 min ergometric aerobic exercise combined with 2 G artificial gravity training prevented those changes.