Leg Extension Crunch (With Stability Ball)

Instructions

1. Lie on your back with a stability ball squeezed between your lower legs, knees bent at 90 degrees.
2. Place your hands behind your head and lift your shoulders off the floor in a crunch.
3. Simultaneously extend your legs to straighten them while holding the ball.
4. Return the knees back toward your chest and lower your shoulders to complete one rep.