Jackknife Crunch on Aerobic Step

The jackknife crunch on aerobic step is a exercise the works the core muscle. Please note that when doing this workout you're working out the hip flexor muscle. This is the muscle allow you to kick a ball or lift the knee from a standing position (as in running).  Thus, if you are trying to isolate the abs, there are better alternatives. Instructions for the jackknife crunch are as follows.

Sit at the edge of the steps, Lean back and place your hands to balance yourself on the step.Extend your legs off the edge of the step, then bring your knees towards chest. As you do so, crunch your abdominal muscles. The knee and crunch motions should take place simultaneously. Be sure to exhale as you contract your abdomen.

Step 1

Sit on step. Lean back and place hands on side of aerobic step.

Step 2

Simultaneously bring knees toward chest and crunch the abs.

Step 3

Return to start position. Repeat as needed.

Triple Layer Workout Mat

The Original Health Club Step

Economy Workout Mat

› Jackknife Crunch on Aerobic Step