I certainly wouldn’t consider myself “well-endowed,” but I would like to point out that CW-X sports bras are awesome. Something like the Extra Support Bra would probably work well. They have a support web (like a five-point harness seatbelt for race cars or baby seats) built into each cup, so they are very effective in preventing any bouncing. They also tend to be much more comfortable than regular sports bras, since they give support without squishing one’s chest. The only downside to the CW-X bras is that they tend to be a bit pricey, but I know many women who have found that they worked when no other sports bras did.