Ab Roll on Ball

1. Kneel in front of the ball and place arms on the ball, elbows bent.
2. Contract the abs and pull the belly towards the spine.
3. Slowly roll forward and out as far as you comfortably can. Don't go so far that you hurt your back or collapse.
4. Keeping the body straight, slowly pull your body back using your arms and abdominals.
5. Continue for 1-3 sets of 8-12 reps, avoiding this move if you have any back problems.
6. You can change the difficult of the move by placing your hands closer in or further out.