What You'll Need
Your favorite, big, blown up, tougher version of a beach ball and an enthusiasm for a stronger core as well.
Why You Should Be Doing This Exercise
Your lower abs called and asked to speak with you regarding your prolonged neglect of them. We took a message and told them to go see the physioball pull-in in the interim. They called back again and thanked us. If you're about it, then you will indulge us and try this.
Get your legs on the ball so that your shins are touching it, and your feet are at the end of the ball. Place your hands in a push-up position (as if you were doing push-ups, with the only difference being the whole feet/shins on ball thing).
Your knees are headed to your chest, but only if your back remains straight (not literally, but in that general direction). The ball should roll forward as well, which means it'll go under your ankles. Think of yourself, from the waist down, resembling an accordion. Fold in, and expand out.
And now your knees have gone forward enough so that your abs are no longer contracting to pull the ball forward. That's excellent. Let's then straighten your legs back out and return the ball to the starting position. That's excellent, now let's… Notice a pattern forming here?
After we took a call from your lower abs, we got one from your back, but it was a pre-recorded message. Here's what it said: "Please don't allow me to drop in, please keep me straight, and forget about letting me arch." Just thought we'd pass the message along.