totally agree with u prae. Urine color tells us a lot about our body condition. 1-2 days before competition, check your urine color & make sure it's clear white. Thats a sign that u're properly hydrated, well if it is colored after u had drank loads of plain water then there might be some other problem with your health.

Read that coconut water can help in avoiding cramps too.

If we drink lotsa coke or sweet stuff oso I notice our pee will become yellowish.
Judging from this, too much sweat drink oso would not be good during tennis?

Gotta drink together with plain water.