What once was springy and fast twitch, is now sloth like.

曾经充满弹性和快速抽动的东西现在变得像树懒一样。

By bending in the middle and using fast twitch muscle fibers, they can whip around without ever changing their net angular momentum.

透过在身体中断弯曲并使用快肌纤维，它们可以在不改变其净角动量的情况下摆动。

But successful basketball players is determined 50 percent by genes in terms of how much fast twitch versus slow twitch they have in their muscles, or how high they can jump, how coordinated they are, how tall they are.

成功的篮球运动员50%是由遗传基因决定的，比如肌肉里有多少快肌纤维和慢肌纤维，或者，能跳多高，协调性如何，身高多少。