How To Do Jackknife Sit Up

Jackknife Sit Up Exercise

Jackknife Sit Up is a great exercise for targeting the rectus abdominis and transverse abdominis.

It also engages the serratus, oblique muscles, hips and lower back.

Jackknife Sit Up creates an intense contraction at the top position for the entire abdominal area.

Jackknife Sit Up can be used as a warm up to prime the hip flexors and lower back before training your back and legs.

It can also be used as a finisher in an abdominal workout routine.

Jackknife Sit Up How To

  • Lie on your back with your knees bent at a 90 degree angle. Your arms should be in a fully extended position behind your head.
  • Rotate your pelvis, to lift your hips off the floor then bring your knees toward your chest. Simultaneously raise your shoulders off the floor by pulling your upper abdominals toward your ribcage and extend your arms past your knees. Hold the position for a count of “one”.
  • Extend the hips to straighten your legs while simultaneously lowering your shoulders back to starting position.
  • Repeat the exercise until you have completed the targeted number of reps.

Form and Technique

Keep your legs as close as possible to increase involvement of the transverse abdominis.

Only go up as high as you can and make sure to get a good contraction at the top position.

Do not let your shoulders or legs rest on the floor on the bottom position in order to maintain constant tension on the abdominal area.

Variations: Jackknife, V Up, Jackknife Crunch

Routine for Strength: 5 sets x AMRAP (30 secs rest between sets)

Routine for Muscle Gains: 5 sets x AMRAP (45-60 secs rest between sets)

Jackknife Sit Up