Jackknife Sit-Up
- Main muscle
- Core
- Difficulty
- Beginner
- Movement
- Core · Single-joint
Equipment
No equipment needed — bodyweight only.
How to do it
- Lie on your back on a mat with legs straight and arms stretched overhead.
- Lift your arms and legs at the same time, reaching your hands toward your feet.
- Slowly lower your arms and legs back to the start.
Beginner tip: If it's too hard at first, bend your knees a little.