I am a 34DD in a regular bra, which means I need a lot of support when I run. I bought this bra in a 34D and I'm glad I did--the DD would not have offered the support and may have caused the bra to "curl up" as other reviewers have mentioned. Once I've got myself installed in it, the girls aren't going anywhere. Yes, it's a bit of a uniboob effect, but that's way better than having underwires pushing into my ribs! I was so excited and amazed to find a non-underwire sports bra that I can wear to run. And it even comes in gorgeous colors in oddball sizes like mine, so I can wear it without a shirt in the very hot Texas summer.