How to do it
Press evenly through both feet to stabilize your base.
- 1
Lie on your back on a stability ball with your feet flat on the floor.
- 2
Hold a weight across your chest or with your arms extended.
- 3
Perform a crunch while simultaneously extending your legs.
- 4
Return to the starting position and repeat for the desired number of repetitions.
Expert tip
Focus on contracting your abs to lift your torso rather than pulling with your neck or arms.
Common mistakes
- ✕Ball shifting out from beneath the spine
- ✕Extending the knees past full lockout
- ✕The weight drifting off center