I have to wear two Champion. (38DD)
It really works well for me. There was an add/poster at Runners Corner for a bra that is made for well endowed gal's that says their bra is supposed to end the doubling up thing. David cracked up when he saw the picture of the runner with 10 bras on. He said, "Hey that's you!!!" I buy them in double packs at costco. They work great. I don't know about distances over 10 miles, though. The only thing I do know for sure is that those beasts must be bound or it is painful and could be dangerous