Works core and legs
In standing position, rest hands on hips. Step right foot back, lower hips and bend both knees at 90 degrees [A]. Then step right foot forward, step left foot back and bend both knees to complete one rep [B]. Back knee should be almost touching floor, and front knee directly above the ankle. Knees should be pointing in same direction as toes. Keep body upright.
Scale up Instead of stepping, jump as you switch sides.