Jackknife (Bench)

A core and hip flexor exercise performed on a bench where you bring your knees toward your chest while lifting your upper torso. This compound movement targets the entire abdominal region.

Instructions

1. Lie on your back on a bench with legs extended and arms extended overhead.
2. Keep your lower back pressed into the bench to engage your core.
3. Simultaneously bring your knees toward your chest and your chest toward your knees.
4. The movement should create a “V” shape with your body.
5. Squeeze your abdominals at the top of the movement.
6. Extend your body back to the starting position in a controlled manner.
7. Maintain control throughout and avoid using momentum.
8. Repeat for the desired number of repetitions.

Tips

• Keep your lower back in contact with the bench to prevent strain
• Move in a smooth, controlled manner rather than explosively
• You can modify the difficulty by keeping knees bent or arms across your chest
• Focus on the quality of each rep rather than speed
• This movement requires good core strength and hip flexor mobility