Back to exercises
StrengthbeginnerBodyweight

Jackknife Sit-Up

Primary
Abdominals
Equipment
Bodyweight
Level
beginner

Jackknife Sit-Up demonstration

Jackknife Sit-Up, starting position
Jackknife Sit-Up, starting position
Jackknife Sit-Up, finishing position
Jackknife Sit-Up, finishing position

How to Perform

  1. 1Lie flat on the floor (or exercise mat) on your back with your arms extended straight back behind your head and your legs extended also. This will be your starting position.
  2. 2As you exhale, bend at the waist while simultaneously raising your legs and arms to meet in a jackknife position. Tip: The legs should be extended and lifted at approximately a 35-45 degree angle from the floor and the arms should be extended and parallel to your legs. The upper torso should be off the floor.
  3. 3While inhaling, lower your arms and legs back to the starting position.
  4. 4Repeat for the recommended amount of repetitions.

Video Tutorial

Tips & Common Mistakes

  • •Focus on controlled movements rather than speed or momentum
  • •Maintain proper breathing - exhale during the exertion phase
  • •Start with lighter weight to master the form before progressing
  • •This is a great exercise for beginners - focus on form over reps
  • •As a compound movement, this exercise works multiple muscle groups efficiently

Muscles Worked

Front
Back
Abdominals

Exercise Details

Category
Strength
Force
pull
Mechanic
compound
Level
beginner

Want workout programs?

Get structured workout plans using this exercise and more.

Browse Programs

Frequently Asked Questions

What muscles does Jackknife Sit-Up work?

Jackknife Sit-Up primarily targets the Abdominals.

What equipment do I need for Jackknife Sit-Up?

Jackknife Sit-Up requires Bodyweight.

Is Jackknife Sit-Up suitable for beginners?

Yes, Jackknife Sit-Up is suitable for beginners. It's classified as a beginner-level exercise.

Alternatives to Jackknife Sit-Up

Substitute any of these when the equipment is taken or unavailable. They train the same primary muscles.