时差N小时 肌肉生而不等

It's not fair!

真不公平！

What's not fair?

什么不公平？

I was rereading the Constitution of the United States. It sayshere that “All people are created equal.”

我又读了一遍《美国宪法》，上面写着：“人人生而平等。”

That's just not true!

事实并非如此!

What do you mean?

你想说什么？

Well, it's always being my dream to become the Olympic champion in the 100-meter-dash.

成为奥运会的百米短跑冠军一直是我的梦想。

But no matter how hard I train, I'm just not fast enough.

可是，无论我多么努力，我就是跑不了那么快。

You just realize this now.

你才意识到啊！

Some guys are simply faster than everyone else.

有些人就是比别人都跑得快。

That's because some people are born with more faster twitch¹ muscle fiber² than others.

那是因为他们天生比他人多快收缩肌纤维。

With what?

有更多什么？

That's a big part of what make people faster than others.

快收缩肌纤维大大地决定了跑步速度。

Muscles are made of two kinds offibers–fast twitch and slow twitch.

肌肉有两种纤维构成：快收缩肌肉纤维和慢收缩肌肉纤维。

What's the difference?

有什么不同吗？

Slow-twitch fibers³ use energy aerobically⁴ and can work for long periods of time before gettingtired.

慢收缩肌肉纤维用于有氧耗能，适合耐力性运动。

So they can contract more slowly, but can keep going without burning themselves out.

所以慢收缩肌肉纤维收缩更慢，但是持续时间更长。

Exactly, since they have to keep going for long periods.

说的对，因为马拉松耗能耗时长。

So sprinters have a lot of fast twitch muscle fiber.

那么，马拉松选手肯定有很多慢收缩肌肉纤维了。

Right! Fast twitch fibers consume energy quickly and are good for short, powerful bursts ofmovement like sprinting⁵ and jumping.

没错！慢收缩肌肉纤维富含肌红蛋白。肌红蛋白可帮助肌细胞将氧转运到线粒体，而线粒体是细胞能源工厂。

World-class sprinters typically have about 80% fast twitchmuscle fiber.

对，快收缩肌肉纤维耗能快，特别适合短而有力的爆发性动作，比如短跑和跳跃，世界级短跑健将体内80%肌肉都是快收缩肌肉纤维。

Luck dogs!

真是幸福！

And, of course, they train incredibly hard to develop their natural gifts. Olympic gold is not wonby muscle fiber alone.

当然，他们不仅仅靠天赋，还有艰苦地训练来完善技能。获得奥运金牌可并非肌肉纤维就可以。

But it certainly helps!

但是不得不承认肌肉纤维起了作用。

1 twitch   

v.急拉，抽动，痉挛，抽搐；n.扯，阵痛，痉挛

参考例句：

• The smell made my dog's nose twitch.那股气味使我的狗的鼻子抽动着。
• I felt a twitch at my sleeve.我觉得有人扯了一下我的袖子。

2 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

3 fibers   

光纤( fiber的名词复数 )； （织物的）质地； 纤维，纤维物质

参考例句：

• Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上，以硫酸钠为凝固剂，对胶原-PVA共混溶液进行湿法纺丝，制备了胶原-PVA复合纤维。
• Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。

4 aerobically   

adv.aerobic（需氧的，需气的，生存于氧气中的）的变形

参考例句：

• Nitrate was aerobically reduced to nitrite. 硝酸盐去氧后转化为亚硝酸盐。 来自互联网
• The main thing is to pick something you can aerobically, and do it! 重要的是挑个有氧活动，并且去做！ 来自互联网

5 sprinting   

v.短距离疾跑( sprint的现在分词 )

参考例句：

• Stride length and frequency are the most important elements of sprinting. 步长和步频是短跑最重要的因素。 来自互联网
• Xiaoming won the gold medal for sprinting in the school sports meeting. 小明在学校运动会上夺得了短跑金牌。 来自互联网