Fortunately, you can have it both ways. You can follow training plans that build the length of your long runs, and others that improve your speed-endurance.

幸运的是，你可以两者都拥有。你可以按照增加长跑距离的计划进行训练，也可以按照提高速度耐力的计划来训练。

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You can follow training plans that build the length of your long runs, and others that improve your speed-endurance.

你可以按照增加长跑距离的计划进行训练，也可以按照提高速度耐力的计划来训练。

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If an athlete trains mainly for speed, those muscle fibers in the middle will act as if they are high-intensity ones, but endurance training will make them behave more like the low-intensity fibers.

如果一个运动员主要是训练速度的，那些介于二者之间的肌肉纤维将像高强度肌肉纤维一样动作，而进行耐力训练将使它们的动作更像低强度肌肉纤维。

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