How to do it
Press your lower back into the floor for the entire repetition.
- 1
Lie on your back with your calves resting on a stability ball.
- 2
Place your hands behind your head or across your chest.
- 3
Contract your abs to lift your torso off the ground while simultaneously pulling your knees towards your chest, rolling the ball towards you.
- 4
Slowly extend your legs back out and lower your torso to return to the starting position.
- 5
Repeat for the desired number of repetitions.
Expert tip
Keep your movements controlled and focus on using your abs to perform the crunch, rather than relying on momentum.
Common mistakes
- ✕Pulling the head forward with clasped hands
- ✕Calves sliding off the ball during knee tuck
- ✕Knees tracking inward as the ball rolls in