Kettlebell One-Arm Russian Swing
Stand about two feet behind a kettlebell with your feet shoulder width apart. Push your hips back and bend your knees to grasp the handle with both hands, then hike the kettlebell back between your legs, keeping your back straight. As it swings forward quickly extend your hips and raise it to shoulder height, arms straight, then guide it back down between your legs under control. Once you establish a good rhythm, release one hand and continue to swing with one arm.