1、You shouldn't try to overexert yourself to reach a peak fitness level or train for a race.
你不可以用力過度來達到身體健康的巔峰狀態(tài)，或者去為比賽而訓(xùn)練。

2、Take care not to overexert yourselves.
小心不要過分操勞。

3、You must not overexert yourself.
你不能過度勞累。