Using a decline crunch allows you keep your legs steady and isolate all of the abdominal muscles.
Steps
Lie on a decline bench face up. Place your feet securely under the pads. Place your hands either across your chest or on either side of your head (over your ears).
Lay fully back and then rise slowly crunching your abs. Pause for a moment and then return to the starting position.
Tips
Use the full range of movement in this exercise for the optimal results.