乏力

liǎng tuǐ fá lì

两腿乏力

be weak in the legs

yī shēng dīng zhǔ wǒ duō zǒu zǒu yǐ cǐ zhì liáo wǒ fá lì de xī gài

医生叮嘱我多走走，以此治疗我乏力的膝盖。

The doctor prescribed walking as therapy for my weak knee.

fù xiè huì ràng nǐ gǎn dào fá lì ér qiě méi yǒu wèi kǒu

腹泻会让你感到乏力，而且没有胃口。

Diarrhoea can make you feel weak, as well as putting you off your food.

huí tiān fá lì

回天乏力

not able to turn the tide

nǐ gǎn dào jīn pí lì jié yā lì hěn dà hún shēn fá lì

你感到筋疲力竭，压力很大，浑身乏力。

You feel stretched thin, stressed-out, drained.