Feel the burn in just 15 minutes with this low impact and pregnancy friendly Short & Sweaty sister workout. A great routine to use as an add-on to a Signature BBB Workout when you want to push yourself a little more, or for when you're just short on time, this arm-focused circuit calls for a set of dumbbells (Kelly was using 10lbs, Liz was using 5lbs) and a low resistance exercise band.