You can replenish 250 ~ 500 cc of water 20 ~ 40 minutes before exercise, and avoid drinking coffee, black tea, cola and strong tea. And it is best to drink juice.

It is not advisable to drink plenty of water during exercise. It is best to replenish about 100 to 200cc of water every 15 minutes. After exercise, you can fully replenish the water you need, and if necessary, you can drink appropriate salt water to replenish the electrolyte lost due to sweating.