- By the time you're thirsty, you're already dehydrated; thirst isn't a reliable indicator of dehydration.
- You need eight glasses of water a day. (Though this is supposed to include the water in your food.)
- If your urine is dark it means you're dehydrated.
These were things my high school nurse and health teacher told me.
I now hear people saying they're rumors spread by Big Sports Drink. So how much truth do they have to them?