There are so many ways to work your abs — standing, on the floor, with or without weights — that there are probably dozens of possibilities you haven't tried. And it's not just for aesthetics; having a strong core supports your back and virtually every movement you do on a day-to-day basis. We could name plenty of exercises we love, but we wanted to hand it off to 11 trainers for their go-to ab moves. This isn't a workout: rather, a collection of some challenging and effective moves you can incorporate into your next home or gym workout. Now, let's get to shredding that core.