Begin this exercise by lying on your back with a Swiss ball under your right or left heel. Your opposite foot should be off to the side of the Swiss ball and off the ground at approximately the same height as the foot on the Swiss ball. Place your arms straight out to your side for support.
Lift your hips so that you create a straight line with your body. Do not use your arms at any point. Take the leg on the ball and bring the ball in towards your body using your heels. Keep your opposite leg straight, slightly higher than the ball. Reverse the movement and lower your hips back to the ground. Trying doing 2 sets with 10-12 repetitions for each leg.
When rolling the ball in towards your body, make sure not to lift your pelvis towards the ceiling. Your hips should stay in the same position – this will force you to use your hamstrings.
Muscles Worked: Hamstrings, Glutes