Lie on your side with your knees bent and feet stacked one on top of the other.
Prop yourself up on your forearm with your elbow under your shoulder.
Tighten your abdominal and buttock muscles, and then lift your hips up off the floor.
You should have a straight line from your head to your knees.
Holding this position, lift your top knee up, keeping your feet together.
Control the movement as you lower your knee back down again and repeat.
