I run about 5 times a week and tried a ton of different "high impact" sports bra made for D cup women and they either were uncomfortable, chafed, or didn't hold the girls up securely.  Until I found this bra.  I love that it doesn't have underwires, which I find chafe no matter what material the bra is made of.  The racer back design gives support without squishing your boobs so tight to your chest you can't breath.  I love this bra and it's now the only one I wear during high impact activity.