(单词翻译:单击)
听力文本
At 14,505 feet, Mount Whitney towers over California's Sierra Nevada range.
It's the tallest peak in the lower 48—which means it attracts thousands of weekend warriors every year—or make that weakened warriors.
You see them staggering along the narrow, rocky trail, huffing for air, dizzy and exhausted from the low oxygen levels at high elevation.
And once they're sick?
"The best medicine is to go down.That's actually the only cure that works."
Svein Gaustad, a physiologist at the Norwegian University of Science and Technology.
He says previous studies suggest blood vessels tend to contract at high altitudes.
Possibly because they need oxygen to relax—exactly what's in short supply on mountaintops.
But there may be a dietary way to get more oxygen to your blood vessels:in the form of beet juice.
The juice contains nitrate, which the body converts to nitricoxide, the compound that keeps arteries limber.
Gaustad and his colleagues tested that theory during a trek in Nepal, at 12,000 feet.
Eight volunteers alternately drank shots of regular beet juice, and another day, beet juice with the nitrates stripped out.
A few hours later, the researchers measured blood flow and artery diameters with ultrasound.
And they found that the regular beet juice did indeed restore blood vessels back to their low-elevation flexibility, whereas the nitrate-stripped juice did not.
The results are in the journal Nitric Oxide.
Gaustad says better vascular function has the potential to deliver more blood—and therefore more oxygen—to tired muscles.
But they still don't know if that translates to better performance at altitude.
And, he says, beets won't hurt, but they're no substitute for proper acclimatization.
"If I had a bottle of beets around I would take it for sure.
But that won't bring you to Mount Everest just by drinking beetroot."
参考译文
属加利福尼亚州内华达山脉的惠特尼山海拔14505英尺。
惠特尼山是美国本土48州的最高峰—这座山每年会吸引成千上万名勇士周末前来这里挑战—但同时也造就了许多虚弱人士。
你会看到这些攀登者在狭窄崎岖的山路上步履蹒跚，气喘吁吁，并且在高海拔低氧环境下筋疲力尽的样子。
但如果他们不舒服怎么办?最好的良药就是下山。
这是唯一有效的方法。
挪威科技大学的生理学家斯威因·加斯特德这样说道。
加斯特德表示先前的研究表明血管会在高海拔地区收缩。
可能因为血管需要氧气舒张—而在山顶时则会面临供氧不足的情况。
但是可以通过饮用甜菜汁这样的形式让更多的氧气进入你的血管。
甜菜汁中含有硝酸盐，而人体可以将这种物质转化成一氧化氮从而保持动脉通畅。
加斯特德和他的同事们在海拔12000英尺的尼泊尔山进行远距离行走检测此种理论。
８名志愿者轮流饮用普通甜菜汁及去掉硝酸盐的甜菜汁。
几小时后，研究者们通过超声波测量血流以及动脉直径。
结果他们发现，普通的甜菜汁确实能将血管恢复到在低海拔时的灵活性，而去掉硝酸盐的甜菜汁却没有这种效果。
这项研究已经在《氧化氮》杂志上发表。
加斯特德表示血管功能更好则代表会输送更多血液—进而为疲惫的肌肉输送更多氧气。
但是，他们仍不知晓是否着在高海拔处会有更好的效果。
而且他表示甜菜不会造成伤害，但是这种饮品不能作为适应环境的替代品。
“如果身边有一瓶甜菜汁，我当然会喝掉。
但是，仅仅靠饮用甜菜汁并不能助你登上珠穆朗玛峰之巅。”
译文为可可英语翻译，未经授权请勿转载！
重点讲解
1.tend to 倾向于
例句:Advocates for this policy tend to stress that it is “ more free ” because it imposes fewer restrictions on users of their software.
这种策略的支持者趋向于强调这种策略“更为自由”，因为它对软件的使用者的限制更少。
2.blood vessel 血管
例句:Or maybe he's got a crushed blood vessel.
也有可能是因为血管破裂。
3.trek 跋涉
例句:It was a long trek, and Jack and I both started to get cranky after about ten minutes.
那是一次长途跋涉，我和杰克走了约10分钟便开始烦躁不安起来。
4.deliver to 交付给
例句:Add other client-side frameworks, CSS layouts, and custom content to create the application you want to deliver to your clients.
添加另外一些客户端框架、CSS布局和定制内容，以创建您想要交付给客户的应用程序。
