这个词组该如何翻译呢

keep one's spirit well ??

就keep fit就可以了吧!

repose养神

yǎngshén

[repose;rest to attain mental tranguility] 使自己的身体与心理处于平静状态,来恢复精神和体力

nourishing spirit
replenishing stamina...

help building one's energy
This food is good for building up vital energy.