My son is eight months old, and even though I got back to my pre-baby weight pretty quickly there's one part of my body that just isn't the same: my abs. So over the next few weeks I'm determined to get my flat belly back. Want to join me? Drop and give me 1 minute of plank! It's one of the most effective moves for targeting all the muscles around your middle, and because it requires no gear, you can do it anywhere (even your office!) Click here for a video of Bob Harper demo'ing how to do it right (hint: don't let your butt rise or fall!).