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

Arnold Press, Dumbbell
Type: Upper, Push
Target: Shoulders
Synergist: Chest, Triceps

Arnold Press, Kettlebell
Type: Upper, Push
Target: Shoulders
Synergist: Chest, Triceps

Around The World, Dumbbell
Type: Core
Target: Shoulders, Chest
Synergist: Back

Back Extension, Bodyweight
Type: Lower, Core
Target: Back
Synergist: Glutes, Hamstrings

Back Extension, Leverage Machine
Type: Lower, Core
Target: Back
Synergist: Glutes, Hamstrings

Ball Slams, Medicine Ball
Type: Core, Upper
Target: Shoulders, Back
Synergist: Chest, Abs

Battle Ropes, Bodyweight
Type: Upper, Core
Target: Shoulders
Synergist: Biceps, Forearms, Back

Behind The Neck Press, Barbell
Type: Upper, Push
Target: Shoulders
Synergist: Triceps

Behind The Neck Press, Smith Machine
Type: Upper, Push
Target: Shoulders
Synergist: Triceps

Behind The Neck Press, Band
Type: Upper, Push
Target: Shoulders
Synergist: Triceps

Bench Dip, Bodyweight
Type: Upper, Push
Target: Triceps
Synergist: Shoulders, Back, Chest

Bench Press, Barbell
Type: Upper, Push
Target: Chest
Synergist: Shoulders, Triceps

Bench Press, Cable
Type: Upper, Push
Target: Chest
Synergist: Shoulders, Triceps

Bench Press, Dumbbell
Type: Upper, Push
Target: Chest
Synergist: Shoulders, Triceps

Bench Press, Smith Machine
Type: Upper, Push
Target: Chest
Synergist: Shoulders, Triceps

Bench Press, Band
Type: Upper, Push
Target: Chest
Synergist: Shoulders, Triceps

Bench Press, Kettlebell
Type: Upper, Push
Target: Chest
Synergist: Shoulders, Triceps

Bench Press Close Grip, Barbell
Type: Upper, Push
Target: Triceps
Synergist: Shoulders, Chest

Bench Press Close Grip, Smith Machine
Type: Upper, Push
Target: Triceps
Synergist: Shoulders, Chest