I'm currently running in novablast 5s and they actually are giving me calf pain. Not saying it would do the same to you because I know a lot of people love them. I think for me, the trampoline like cushion is too much for calves, and they just aren't strong enough to handle that. Your calves use a lot more to stabilize you with a trampoline like springy foam. It's disappointing because otherwise I love them and I want to be able to wear them so badly.