This might be a nice t-shirt bra. It's smooth and comfortable. But it provides no more support than my regular, everyday bra.
I'm a 40DD. This was a snug 40, but acceptable. The cups, however, are very thin and stretchy, so they don't prevent any bounce. In fact, I think it allows more bounce than my regular bra, which does not stretch.
I wasn't looking for a super-duper sports bra; I have an Enell for that. I wanted something a little less constricting to wear during yoga and walks. But I may as well just keep wearing my usual bra, because it gives me the same level of support.