Lie on a mat or flat bench. Steady yourself by pressing your arms and hands on the mat or bench, as pictured.

 

Bend your knees and start pulling them toward your chest. Your knees should be bent with your thighs flexed at the hips so that your knees are over your torso. Your buttocks should not be touching the floor or bench. This is the starting position.

 

Shorten your torso by bringing your abdominal muscles forcefully.

 

Slowly return to the starting position, but without your buttocks ever touching the floor or bench.

 

Repeat the exercise for the recommended number of sets and repetitons.