How do you women do it?

Running 18 miles the other day, I was reminded about the biggest downfall of Marathon training.. Not the stiff-legs, not the sore feet, not the tight back but rather the biggest hurdle is something that would not imagine would be something I'd ever have to worry about.

Now this doesn't seem to be a big problem for shorter runs but get me to run for 2 to 3 hours wearing one of those synthetic cotton dry-weave synthetic shirts and all of a sudden I face the most excruciating pain you can imagine. The first time I finished a 2 hour run I looked down to see a trail of blood trickle down the front of my shirt.

My name is Righetti and I suffer from bloody nipples. They aren't caused by rough sexy time but instead caused by the irritation of 2 hours of nipple chaffing. The sweat from the run seeps into the cuts causing intense pain, so for days after a long run I have to walk around pulling my shirt away from my skin because any impact seems to trigger the pain.
Now to try avoid it I'm forced to wear the equivalent of stripper pasties, shit if it worked I'd consider wearing a sports-bra.