Primary Muscle Group: Hamstring
Muscle Groups Worked in This Exercise: Hamstring, Calf, Inner Thigh
Preparation: Lie in prone position on the floor with a stability ball squeezed between the sides of your feet on the floor extended outward.
Breathing: Breath out on the contraction of the muscle and breath back in on the way back to the start position.
Execution: Curl your feet upward towards your glutes as your squeeze the ball between your feet and focus on squeezing in your hamstring muscles. Move back to start position and repeat.