I just put this bra to the ultimate test... I got on the trampoline with my kids and I had NO problems with bouncing boobs! This is after wearing it all day so the day didn't stretch out the support. I am a 36 C/D and nursed my twins 7 years ago so you can imagine the shape my girls are in 😕. It was comfortable all day and wore it under a tank top. It looked like I layered over another tank so I didn't have to worry about the bra showing. I highly recommend you look at the manufacturers size chart. I almost ordered a medium instead of a large and that surely would have been too tight.