DH and my sister are currently doing the Insanity program at home. DH and I just had hardwood floors put in and we immediately realized that we'll probably have to pick up some exercise mats for them to not make so much noise for our downstairs neighbors (we live in a condo).
However, after looking at a few mats there is a disclaimer that is kind of alarming. Here's the whole description:
Re: XP: Gym Mat Warning!