Targetting your workout ... to your whole body.

Take two dumbbells, and one exercise ball.

Sit on the exercise ball with the weights in your hands, and walk your feet forward. As you roll off the ball, lean back and keep your butt off the ground, until the ball is only touching your upper shoulders, neck, and head.

Your knees should be bent at a 90 degree angle, and most of your torso should be parallel to the ground. Your only support should be at your feet, and the ball at your shoulders.

Now push the weights upward as you would if you were laying on a bench, but only do one at a time.

If you're doing it right, your thighs, abs, sides, back, and chest should be flexing to keep your body horizontal. Pushing up one weight at a time throws off your balance slightly, and causes your sides and abs to work to keep you balanced. For a harder workout, bring your feet closer together so you need to use your muscles more for balance.