I can't be on my legs too long and can't walk long distances.

我不能长时间站着，也不能走很远的路。

youdao

On the day of the Marathon I started well, but after half Marathon I developed muscle cramps on both legs which caused me to fall on the tarmac, which caused my right knee to be badly bruised.

马拉松比赛那天，我一开始的状态很好，但到后半程的时候，两条腿都出现了肌肉痉挛，这直接导致我跌倒在跑道上，造成我的右膝严重受伤。

youdao