Begin by lying down on either a flat bench or a floor mat. Grasp a medicine ball (or straight bar). Press the ball up above the chest in the same manner you would doing a bench press. Keep your knees slightly bent and your legs together. Raise your legs slightly off the ground.

Lower the ball behind your head as far as you can without feeling discomfort in your shoulders. Make sure you keep your arms slightly bent. As you lower the ball, inhale deeply.

Using your shoulders as your axis, raise the ball forwards over your head toward your legs, while lifting your legs towards the ball at the same time. As you raise the ball, concentrate on lifting your shoulders as high as you can and try to touch the ball to your ankles - the two should meet somewhere over the abdominal wall. Exhale forcefully as you perform this part of the exercise and contract your abdominals and serratus as you lift your shoulders high.

Added difficulty: Increase the weight as you become stronger. For a blow-out at the end of your sets, lower your legs first and hold for one second. Then lower the ball behind your head and hold for a second. Then complete the exercise.