It would be terribly difficult for a bladder to handle that amount of fluids, youd have to drink nonstop all day to get the daily amount. The majority of the day would be spent in the loo. You would eventually be able to hold a little more for a little longer as time went.
They probably do so by not taking it too literally!
The recommended daily intake of water (I forget what it is - 5 litres?) does not need to be just one jugful of tap-water after another, but is made up of the total water in your normal food and drink.
Your body will tell you if it needs a bit more than you've already drunk.
@skmokisses that does seem about right. Most of us excrete about a little less than a gallon of urine a day. I work out pretty strenuously most mornings and lose a lot through sweat and breathing, so I probably end up drinking more. If you live in a really hot and dry place, like Phoenix, they teach children Not to wait until they are thirsty, but drink something every hour.
@samueltyler2 It's taking some getting used to. I've just drank water unless it was during or after a work out. So I never got nearly enough. Trying to do better by that. I think I am up to 46 ounces for today.
@DIABLISS the water filled bladder gave an easier, better view of the rest of the pelvis without any obstruction. That requires ingestion of the water and for the kidneys to have enough time to fill the bladder.
