You will need a stability ball for this exercise.
The Jack Knife exercise is great for your Core. Its hard enough just to stabilize your body on the ball, but we’re gonna add some movement to make it a harder exercise.
Begin with your hands under your shoulders, your back straight, bring your belly button to spine, your feet on the ball (hip width apart) and your knees straight.
While keeping your back straight and maintaining balance, roll the ball forward bringing your knees towards your chest.
**The biggest mistake people make with this exercise is that they allow their back to round when rolling the ball forward. Keep your head, mid-back and low-back in a straight line while attempting this exercise**
Stay balanced. Stay Focused. And just roll with it!
In order to achieve something you’ve never done before, you must be willing to become somebody you’ve never been before