菇凉你还年轻别用旧身体
[gū liáng nĭ hái nián qīng bié yòng jiù shēn tĭ]
The phrase literally translates to 'Girl, you're young; don't use an old body.' It's a metaphor suggesting that young people should value and take care of their health or vitality, instead of overworking or mistreating themselves prematurely.