Holding a dumbbell in your right hand, stand with your feet together.
Take a large step with your left foot out to the left side, sitting your hips backward and bending your left knee into a lateral lunge, allowing the dumbbell to lower along the right side of the leg (pictured).
Make sure your left knee does not extend past your toes, and keep your right leg relatively straight.
Push off through your left foot to return to the starting position. That's one rep.