Weighted Crunch

Step 1. The Weighted Crunch is a variation of the classic crunch exercise that involves adding resistance (a weight) to increase the intensity of the abdominal work.

Step 2. - Lay down

Step 3. - (Optional) Bend your knees to add difficulty

Step 4. - (Optional) Bend your knees and let your feet rest on a bench or a box or something (90 degree angle on knees)

Step 5. - Lift your head and torso while bending your back forward (if you don't it's a sit-up and also involves some back muscles). The higher you go, the more you should feel your abs contracting.

Step 6. - Go back to starting position an repeat