What it does?
The 'jackknife' is an advanced exercise for the abdominals which focuses on the core stabilisers and lower abs
What you need?
A swiss/gym ball
How do you do it?
- Get yourself into a press-up position with your shins or feet resting on the top of a swiss ball
- Lift your bum up slightly for good posture
- From this position, begin to pull the ball in towards your body by driving your knees towards your chest
- Pause briefly at the end of range then extend your legs to return the ball to the start position
- Use a tempo of 2-3 seconds in, 2-3 seconds out
- Repeat 8-10 times and do 3 sets
Key Points
- Control the movement with your abdominal muscles whilst performing the movement
- Prevent your back from sinking by using your abs
