Health and Integrative Physiology Laboratory, School of Kinesiology, University of British Columbia, Vancouver, Canada.
Eur J Appl Physiol. 2012 Sep;112(9):3287-94. doi: 10.1007/s00421-012-2308-x. Epub 2012 Jan 18.
In mountaineers, recent altitude exposure has been shown to improve climbing performance and clinical outcomes during re-exposure to high altitude. However, the timing of previous altitude exposure has not been clearly reported and previous findings might be driven by individuals who were still acclimatised at the time of re-exposure. Our goal was to determine whether recent altitude exposure would confer an advantage even in individuals who had de-acclimatised for ≥ 1 week before being re-exposure. Low-altitude natives kept a daily trekking log throughout 7- to 8-day trek from Lukla (2,840 m) to Gokyo Ri (5,360 m). Trekkers with recent altitude exposure (re-acclimatisers, RA; n = 20) walked 20% faster (p < 0.01), reported lower acute mountain sickness scores (9 ± 8 vs. 15 ± 13; p = 0.02), and used less medication to treat headache (p < 0.05) compared to trekkers with no recent altitude exposure (initial acclimatisers, IA; n = 30). On Gokyo Ri, S(p)O(2) was significantly higher in RA than IA trekkers (85 ± 6 vs. 78 ± 6; p = 0.01). These data indicate improved functional outcomes and physiological compensation for hypoxia in RA. However, even after de-acclimatisation for 7-30 days, it is possible that RA trekkers began the trek in a more acclimatised state than IA trekkers. RA trekkers might represent a self-selected group that has previously tolerated altitude well and has therefore opted to return. Some findings might also reflect improved psychological altitude tolerance in RA. A direct comparison of the functional and physiological responses to hypoxia throughout an initial and re-acclimatisation to high altitude is needed.
在登山者中，最近的高海拔暴露已被证明可以改善重新暴露于高海拔时的攀登表现和临床结果。然而，之前高海拔暴露的时间并没有被明确报告，以前的发现可能是由重新暴露时仍在适应的个体驱动的。我们的目标是确定即使在重新暴露前已经脱适应超过 1 周的个体中，最近的高海拔暴露是否会带来优势。低海拔本地人在从卢卡拉（2840 米）到岗日里（5360 米）的 7-8 天徒步旅行中每天都记录徒步日志。有近期高海拔暴露的徒步者（再适应者，RA；n=20）行走速度快 20%（p<0.01），急性高原病评分较低（9±8 分与 15±13 分；p=0.02），且使用较少的药物治疗头痛（p<0.05），与没有近期高海拔暴露的徒步者（初始适应者，IA；n=30）相比。在岗日里，RA 徒步者的 S(p)O(2)显著高于 IA 徒步者（85±6 分与 78±6 分；p=0.01）。这些数据表明 RA 徒步者的功能结果和对缺氧的生理代偿得到改善。然而，即使在脱适应 7-30 天后，RA 徒步者在开始徒步旅行时可能比 IA 徒步者处于更适应的状态。RA 徒步者可能代表一个自我选择的群体，他们以前耐受高原良好，因此选择返回。一些发现也可能反映了 RA 徒步者在心理上对高原的耐受性提高。需要直接比较初次和再适应高海拔时对缺氧的功能和生理反应。
