Description

The jackknife is an exercise to train the abdominal muscles. The focus of this exercise is on the straight abdominal muscles.

Exercise

Folding knife

With exercise ball

Type: Bilateral Rest: 120s Equipment: Pezziball

Tutorial

1

Lie on your back on the floor. Keep your arms and legs stretched. Clamp an exercise ball between your feet.
2

Bring your arms and legs together at the top by tensing your abdominal muscles. Transfer the exercise ball from your feet to your hands. Breathe out as you do this.
3

Slowly bring your arms and legs back to the starting position. Keep your abdominal muscles tensed even in the lowest position. Breathe in as you do so.
4

One repetition has now been completed. Repeat this process for the specified number of repetitions. After each repetition, switch the exercise ball from your feet to your hands and vice versa.

Tip

Your lower back is in contact with the floor throughout the exercise. Do not rest your head on the floor in the lowest position. Your abdominal muscles are tensed throughout the exercise.