No it doesn't have anything to do with the size of your breasts. Sports Bras most definitely show nipples. What i advise you to wear is a padded cupped bra with underwire, (you could go to wal mart, lasenza girl, lasenza, or Victoria secrets to get your bra size measured) the underwire helps support the breasts as it grows so when you're old it won't be droopy and saggy. As for the swimming part, alot of peoples' nipples show when they're swimming because in the water, you get cold and just like goose bumps your nipples raise up. One way to hide them is to buy a padded breast area swimsuit, you can get a cheap one from wal mart, or even department stores. That way no matter how cold or how much your nipples show, they won't!
Typically swimming sports...
Swimming, diving, synchronize swimming
swimming
You should maybe exercise at the swimming pool with your friends and swimme 2ith them. You can go to the street to run. Sports can be anywere were you have space.
Swimming and diving
Swimming.
swimming
Swimming
swimming
There are a couple of sports that are played individually. Their is Golf, Swimming, Tennis, and Skiing.
Some of the first sports were wrestling and swimming.
Biking, Swimming, and Running are the sports in a triathlon.