First off these are the most comfortable sports bras I've ever worn. But on that same note I would say these are pretty low impact, maybe medium depending on how big the tiddies are.I'm a 32DDD,DD on a good day, and I can do weight lifting, biking, and stair climber at the gym with little issue. I highly doubt I would be able to do any sort of HIIT workout or anything more intense than a fast walk without jiggling all over the place.
Rating: [4 of 5 Stars!]