Primary Muscle Group: Buttocks and backs of thighs
Muscle Groups Worked in This Exercise: Gluteus Maximus, Quadriceps
Preparation: Kneel on the floor with the ball right in front of you. Place your forearms on the top of the ball and lean forward. Pull your navel in towards your spine and engage your abs as you extend your right leg behind you.
Breathing: Exhale as you lift your leg, inhale as you lower your leg.
Execution: Lift the leg you have extended behind you as high as you can. Be careful not to arch your back. Inhale and lower your leg. Switch to the other leg after completing all reps.
Comments: Guess what, this one strengthens your arms too!