Jackknife Sit-Up

A compound abdominal exercise where you simultaneously lift your arms and legs to meet in the middle of your body, targeting the core muscles.

Instructions

1. Lie flat on your back on an exercise mat with your arms extended straight behind your head and your legs extended on the floor.
2. Your body should be in one long line from fingertips to toes; this is the starting position.
3. As you exhale, bend at the waist while simultaneously lifting your legs and arms off the floor.
4. Bring your arms and legs to meet in the middle of your body in a jackknife position.
5. Your legs should be extended and lifted to approximately 35-45 degrees from the floor.
6. Your arms should remain extended and parallel to your legs, with your upper torso off the floor.
7. Hold briefly at the top position where your hands and feet are closest together.
8. As you inhale, lower your arms and legs back to the starting position with control.
9. Repeat for the recommended number of repetitions.

Tips

• Perform this exercise smoothly without jerking or using momentum to drive the movement.
• Keep your movements controlled throughout, especially when lowering back to the start.
• For an easier variation, bend your knees slightly rather than keeping legs fully extended.
• For a more challenging variation, increase the range of motion or add ankle weights.
• Focus on core strength and stability rather than speed.
• Exhale as you lift and inhale as you lower for proper breathing coordination.
• This exercise effectively targets both upper and lower abdominal muscles.