英语听力文摘 English Digest 411、天冷不宜锻炼？（在线收听）

Too Cold to Exercise?
天冷不宜锻炼？

D: Woo……It's freezing out.

Y: Come on, It's not that cold.

D: Sure it is. Yael.I guess there's just no way I can go jogging today.

Y: Oh, so that's what this all about.

D: Not really. What if my lungs freeze?

Y: Actually, your body is designed so that by the time air reaches your lungs, it’s been warmed up and moisturized by your nasal passages, throat, and trachea. Besides, the blood supply in your lungs is so well developed that there’s virtually no way they can freeze–the circulating blood keeps them nice and toasty.

D: Oh,yeah. So why does it hurt to breathe this really cold?

Y:Well,when the air is frigid, it doesn’t warm up sufficiently before it reaches the airways leading to your lungs, and so it shocks the surrounding muscles and causes them to contract. This, in turn, causes your bronchial tubes to contract too, which results in that tight, prickly feeling.

D: Uh,sounds dangerous especially when you exercise in breathe to your mouth. What if my tongue freezes?

Y: Well,Don.Unless you suffer from asthma, breathing in cold air won’t hurt you–and you’d have to worry about frostbite to your fingers and toes long before worrying about your tongue freezing.

D：哇，外面太冷了。

Y：不会吧，没那么夸张。

D：确实很冷啊。我想今天也没办法跑步了。

Y：原来你是不想锻炼。

D：也不完全是。如果我的肺结冰了怎么办？

Y：实际上，我们的身体是有应对措施的。当空气进入肺部之前就已经被鼻腔，喉咙和气管加湿，加热。另外，肺部里的血液供给很充足，几乎没有可能结冰-——血液循环让肺部保持正常和舒适。

D：是吗？那为什么在呼吸冷空气时会疼痛？

Y：因为在寒冷的空气到达通向肺部的气管时还没有得到充分的热身，所以冲击到周围的肌肉使其收缩。转而使得支气管收缩，因此你就会有紧绷刺痛的感觉。

D：听起来很危险，特别是用嘴呼吸时，如果我的舌头结冰的怎么办？

Y：吸入的冷空气不会对你造成伤害，除非你患有哮喘。你应该担心手指和脚趾的冻疮而不是舌头结冰。