How to perform Bodyweight Jackknife Sit Up with proper form
Starting Position
- Lie Down: Start by lying flat on your back on a mat or comfortable surface.
- Body Alignment: Extend your arms straight above your head and legs straight on the floor, keeping your body in a straight line.
Movement
- Engage Core: Tighten your abdominal muscles.
- Lift: Simultaneously raise your legs and upper body off the ground, bringing your arms towards your legs. Think of forming a 'V' shape with your body.
- Reach: Aim to touch your toes or get as close as possible while keeping your legs straight.
Return
- Lower Body: Slowly lower your upper body and legs back to the starting position in a controlled manner.
- Maintain Control: Avoid letting your back arch excessively and keep the movement smooth.
Key Points
- Breathing: Exhale as you lift your body and inhale as you return to the starting position.
- Keep Control: Focus on maintaining stability throughout the movement.
- Avoid Strain: Do not pull on your neck; use your core muscles for movement.
Common Mistakes
- Lifting your head and neck too aggressively.
- Arching the back instead of engaging the core.
- Rushing through the exercise instead of performing it slowly and with control.
By following these instructions, you can effectively perform the Bodyweight Jackknife Sit Up with proper form.
Exercises

Ab Wheel, Bodyweight
Type: Core
Target: Abs
Synergist: Hamstrings, Quadriceps, Shoulders, Back, Chest

Bicycle Crunch, Bodyweight
Type: Core
Target: Abs
Synergist: Glutes, Quadriceps

Cable Crunch, Cable
Type: Core
Target: Abs

Cable Twist, Barbell
Type: Core
Target: Abs
Synergist: Glutes

Cable Twist, Cable
Type: Core
Target: Abs
Synergist: Glutes

Cable Twist, Band
Type: Core
Target: Abs
Synergist: Glutes

Cable Twist, Bodyweight
Type: Core
Target: Abs
Synergist: Glutes

Cable Twist, Leverage Machine
Type: Core
Target: Abs
Synergist: Glutes

Cross Body Crunch, Bodyweight
Type: Core
Target: Abs
Synergist: Glutes, Quadriceps

Crunch, Cable
Type: Core
Target: Abs

Crunch, Bodyweight
Type: Core
Target: Abs

Crunch, Leverage Machine
Type: Core
Target: Abs

Flat Knee Raise, Bodyweight
Type: Core
Target: Abs
Synergist: Hamstrings, Quadriceps

Flat Leg Raise, Bodyweight
Type: Core
Target: Abs
Synergist: Hamstrings, Quadriceps, Glutes

Glute Bridge March, Bodyweight
Type: Lower, Legs
Target: Glutes, Abs
Synergist: Hamstrings, Quadriceps

Hanging Leg Raise, Cable
Type: Core
Target: Abs
Synergist: Quadriceps, Glutes

Hanging Leg Raise, Bodyweight
Type: Core
Target: Abs
Synergist: Quadriceps, Glutes

Jackknife Sit Up, Bodyweight
Type: Core
Target: Abs
Synergist: Hamstrings, Quadriceps, Glutes

Knees to Elbows, Bodyweight
Type: Core
Target: Abs
Synergist: Quadriceps

Oblique Crunch, Bodyweight
Type: Core
Target: Abs