夏练三伏，冬练三九

夏练三伏，冬练三九

Literally means:

train in the hottest days in summer and the coldest days in winter; practice winter and summer

Actually means:

三伏, the hottest days in summer; 三九, the coldest days in winter; 练, exercise one's body or practice sports.

This phrase means one should persevere in physical exercise or training in the hottest and the coldest days of the year.

It stresses that training or exercise in a very hard condition is more effective and rewarding. Commendatory.

三伏，夏季最热的一段时间。三九，冬季最冷的一段时间。练，锻炼身体或体育训练。

夏练三伏，冬练三九，指在大热天或大冷天更要坚持身体或体能的训练。

强调在艰苦的条件下训练或锻炼效果更好，收获更大。具有褒义色彩。