Abdominal Crunch (Machine — Seated or Supine)

1.   Select a weight that you're able to use for eight to twelve reps with strict form.

2.  Adjust your seat position based on the guidelines on the machine. In general, your navel should be aligned with the centerpoint of the cam.

 
3.   Sit or lie down and place your feet behind or on top of the pads (the placement of your legs and feet will depend on the type of machine). If seated, place your feet behind the pads that are under the seat.

 
4.   Place your hands lightly on the grips near your chest or beside your head, and position your chest, if appropriate, against the pad (or pads).

 
5.   Position your feet, knees, and thighs so they are no more than 6 inches apart.

6.   Flatten your back, exhale, and flex your abdominals as you "crunch." Lift the weight with your abdominals instead of with your arms. Be sure to curl up very slowly, tensing your abs as hard as you can.

7.   Pause for one full second when your abs are maximally tensed.

8.   Inhale and lower the weight until the plates nearly touch the stack.

9.   Repeat until you reach failure (you can't perform any more reps with strict form).


Other Key Points and Reminders

  If you're in the supine position, keep your head in contact with the pad.
  As you flex your abdominal muscles, flatten your back without lifting your hips.
  Only use weight that you're able to lift without having to use your arms.
  Try not to hold your breath at any time when performing this lift.