Too much distance work can convert fast twitch muscle fibres into slow twitch fibres and can actually decrease an athlete's speed over time.

太多的长途运动会造成快肌纤维转换成慢肌纤维，并随着时间的推移，逐渐减慢运动员的速度。

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As noted, we lose muscle mass with age. Especially quick to deteriorate are fast-twitch muscle fibers, which power quick, explosive movements.

如上而言，随着年纪的增大我们的肌肉会失去力量，尤其是快速收缩的肌肉纤维更为明显，这部分纤维让我们跑得快，启动有爆发力。

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We have two basic types of muscle fibers, slow twitch and fast twitch.

我们每个人有两种基本的肌肉纤维，慢抽搐和快抽搐肌纤维。

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Or the gene that produces more fast twitch muscle fiber and has been found in all Olympic sprinters.

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