Here is a variation on a lunge where you use a medicine ball to twist for your oblique muscles. Search for the lunge blog post for the proper way to do a lunge. Grab a medicine ball with a high enough weight to give you a workout and that you can use for four sets of ten repetitions. If this is too many repetitions for you, do two sets of ten repetitions. One repetition consists of lunging once with your right leg and once with your left leg.
Hold the medicine ball in front of your waist. Once you are down in the lunge position, twist right and left, and return the medicine ball to center as you are getting up to the original position. Repeat for the other leg. Make sure to keep your back vertical. This further engages core muscles. For a harder workout, hold your arms straight out chest level with the ball.
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