Begin this exercise by lying flat on your back with a Swiss ball under your heels. Place your arms straight out to your side for support. Keep your feet flexed, digging your heels into the ball.
Do not use your arms at any point, and keep your hips/glutes flat on the ground.
EXHALE: Roll the ball in towards your body using your heels.
INHALE: Slowly return to start to complete one rep.
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. Concentrate on pressing the ball into the floor with your heels.
Muscles Worked: Hamstrings, Glutes