MAN. I really wished these had worked. I have a 34DD chest so I went with the Large. Just tried one on and jogged in place.. and my boobs not only bounce, but they bounce inside the material while bouncing, creating a very weird shifting feeling, haha. I took out the padding, and they still bounce quite a bit, but just saggier looking :(  I may try to swap out for the Medium to see if it's a tighter hold.

But yeah, they're a verrrry loose stretch. I can pull the straps up to my ears, which means they probably wouldn't last through a few washes.