It's not just women that have to pee lots on rides. I'm good for about 90 minutes before it's time to go.

A Physician's Assistant friend of mine said the two products of metabolizing carbohydrates are carbon dioxide and water. So if I have to pee lots, it means my water intake is enough or almost enough to keep up with the rate at which I lose water through sweat.

I'm wondering if there isn't another reason though. I came up from a hard ride the other night knowing I was dehydrated. Still had to pee after the ride.