You should conserve strength and store up energy before the exam.

你应该在考试前养精蓄锐。

He decided to take a few days off to conserve strength and store up energy.

他决定休假几天，以养精蓄锐。

Athletes need to conserve strength and store up energy before the competition.

在比赛前，运动员们需要养精蓄锐。