I don't do running at the gym, but I do a lot of elliptical training. Which can, at times, lead to very uncomfortable bouncing for my 36D's. After I wore out my old sports bra, I decided to invest in a new one. After seeing all the great reviews, I decided to try it. Although I was skeptical about the velcro, I hoped it would be worth it. And it was! The adjustable velcro is actually really nice. I adjusted it tighter. It's really a great feature. And it held up. A few months later, I am still pleased with it. The velcro is keeping and there is barely any jiggle or bounce. I recommend this for anyone with medium or large sized breasts.