Stability Ball Leg Lifts

Here's how to do the stability ball leg lift:

Start sitting on the ball with a secure bench behind you. Find one that is heavy enough not to wobble or one that is screwed into the floor. Place a light free weight in front of your feet on the floor (5 lbs shown here). Bend backwards and grasp the bench with your hands. Try to situate yourself far enough away so that your arms are straight and the ball is under your lower back/glutes. Also, try to find a ball that is the same height as the bench. This will help to avoid slanting like in the picture below. Now, pick up the weight with your feet and lift your legs above you.

CAUTION: HOLD THE WEIGHT FIRMLY. A LOOSE GRIP WILL CAUSE THE WEIGHT TO FALL ON YOUR HEAD!
Try to keep your neck in-line with your spine as this move causes a lot of neck strain when done incorrectly. Now lower your legs until your body is parallel to the floor. This is where you will feel your abs tighten. Repeat until your set is complete.
Modifications:

To make this move easier, do it without any weight between your feet. You can also do leg lifts on a bench (like the one shown above) or on the floor but trust me, your results will not be nearly as good!

For a greater burn, try using a heavier weight. A small increase in weight makes this move significantly harder so you may want to use strap-on ankle weights to avoid dropping a heavier weight on yourself!