This is a great rotational trunk exercise and also a good conditioning exercise. In an athletic stance, grab the dumbbell handle with one hand over the other or the fingers interlaced. Bend the knees and hips slightly and pull the dumbbell down to the side of one hip. Drive with the legs and rotate the trunk as if you're going to throw the dumbbell across your opposite shoulder. Keep the elbows bent and the dumbbell close to the body and let the hip and trunk power bring it up to the opposite shoulder. Immediately reverse its direction to bring it back to the starting hip position.