Lie supine (on your back) on the floor with your feet together.
Place your hands alongside your body, with your palms flat on the floor.
Lift your legs a little off the floor and bend your knees 90 degrees.
To support your lower back, press it against the floor.
Exhale as you flex your abdomen and curl your hips off the floor.
Try to hold the contracted position for two seconds.
Inhale as you relax your abdomen and lower your hips to the starting position in a controlled manner.
Repeat for the prescribed number of repetitions.
Comments and tips
Keep the movement slow and controlled. Do not use momentum.
Try to resist the lowering of your hips.
Keep your feet off the floor.
Keep your lower back straight so that it makes contact with the floor. If this is difficult for you, place your hands under your buttocks. This will help to straighten your lower back as well as support your pelvis. See video.
In one study by the American Council on Exercise (ACE), compared with the traditional crunch, the reverse crunch was found to produce 9% more mean activity in the rectus abdominis and 140% more mean activity in the obliques.
It is a myth that the reverse crunch works your lower rectus abdominis and the traditional crunch works your upper rectus abdominis. Your rectus abdominis is a single muscle that contracts in its entirety irrespective of the type of crunch that you perform. It is not possible to isolate a specific section of the muscle.