時差N小時:肌肉生而不等

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真不公平!

What's not fair?

什么不公平?

I was rereading the Constitution of the UnitedStates. It sayshere that “All people are createdequal.”

我又讀了一遍《美國憲法》，上面寫著：“人人生而平等。”

That's just not true!

事實并非如此!

What do you mean?

你想說什么?

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

成為奧運會的百米短跑冠軍一直是我的夢想。

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

可是，無論我多么努力，我就是跑不了那么快。

You just realize this now.

你才意識到啊!

Some guys are simply faster than everyone else.

有些人就是比別人都跑得快。

That's because some people are born with more faster twitch muscle fiber than others.

那是因為他們天生比他人多快收縮肌纖維。

With what?

有更多什么?

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

快收縮肌纖維大大地決定了跑步速度。

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

肌肉有兩種纖維構(gòu)成：快收縮肌肉纖維和慢收縮肌肉纖維。

What's the difference?

有什么不同嗎?

Slow-twitch fibers use energy aerobically and can work for long periods of time beforegettingtired.

慢收縮肌肉纖維用于有氧耗能，適合耐力性運動。

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

所以慢收縮肌肉纖維收縮更慢，但是持續(xù)時間更長。

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

說的對，因為馬拉松耗能耗時長。

So sprinters have a lot of fast twitch muscle fiber.

那么，馬拉松選手肯定有很多慢收縮肌肉纖維了。

Right! Fast twitch fibers consume energy quickly and are good for short, powerful burstsofmovement like sprinting and jumping.

沒錯!慢收縮肌肉纖維富含肌紅蛋白。肌紅蛋白可幫助肌細胞將氧轉(zhuǎn)運到線粒體，而線粒體是細胞能源工廠。

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

對，快收縮肌肉纖維耗能快，特別適合短而有力的爆發(fā)性動作，比如短跑和跳躍，世界級短跑健將體內(nèi)80%肌肉都是快收縮肌肉纖維。

Luck dogs!

真是幸福!

And, of course, they train incredibly hard to develop their natural gifts. Olympic gold is notwonby muscle fiber alone.

當然，他們不僅僅靠天賦，還有艱苦地訓練來完善技能。獲得奧運金牌可并非肌肉纖維就可以。

But it certainly helps!

但是不得不承認肌肉纖維起了作用。