Lie on side with legs bent back 90 degrees, one leg on top of the other. Place forearm under shoulder perpendicular to body.
Keeping shank of lower leg on mat or floor, raise hips up off ground while raising upper leg upward away from lower leg. Return to original position and repeat. Continue with opposite leg.
Exercise can be performed by rising only leg upward, keeping hips down.
Exercise can be made more challenging with legs straight