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Stability ball floor leg curls

RealJock Staff

This exercise provided courtesy of Mike Clausen, founder and co-owner of DIAKADI Body training gym, voted best personal training gym in San Francisco by CitySearch in 2006.

Runners and cyclists will love the hamstring-strengthening potential of this leg exercise. Stability ball floor leg curls isolate the back side of the leg—with a particular focus on the hamstring.

Muscles worked
Hamstring, gluteus and calf muscles

Starting position
Lie on your back on the floor or a floor mat with your heels on top of a stability ball and your hip and buttocks off the floor. Keep your arms on the floor with your palms facing down (see Photo 1).


  1. From the starting position, pull your heels in toward your buttocks as far as you can go, preferably until the ball touches your butt (see Photos 2 and 3).
  2. When you have pulled the ball in as far as you can, reverse the motion and extend the ball back out to starting position (see Photo 4). As you repeat the motion, focus on the muscle contraction more than the momentum of the movement.
Initially most people need to use both feet to control the movement of the ball. As you develop strength and coordination, try doing the exercise using one foot at a time. You should also try using different-sized stability balls to work different angles of the muscles.

About Mike Clausen: Clausen is the founder and co-owner of DIAKADI Body Personal Training and Wellness Center, which was voted best personal training gym in San Francisco by CitySearch in 2006. He has been actively involved in sports and weightlifting since high school, and continues to use that knowledge when training his clients. Clausen is both A.C.E. and N.A.S.M. certified and has been training clients professionally for six years. He enjoys making his clients stronger, both physically and mentally, giving them the tools to create an efficient body and to do things they thought were not possible.