Works the gluteus medius of lifted leg

* Attach an ankle cuff to a low-cable pulley machine and place a stability ball lined up with the cable head.
* Place a cuff on your right leg, then lie on your left side on top of the ball, slightly bending your left knee.

* Lift your right leg as high as you can, pausing to squeeze at the top without rolling on the ball.
* Lower leg, keeping resistance on the cables so weights on the stack don’t clank together. Do all reps, then switch legs and repeat.

Trainer's tip: Don't let your hips hinge forward; keep them square by contracting your abs.