They are a great exercise to strengthen muscles at sides of hips, thighs, lower back and buttocks. Stand up and hold on to a chair, for example, for better balance. You can be laying on the floor as well. Lift one leg out to the side, keep your back straight, and bend the other leg just a little bit for support. As with every exercise, don’t rush. Do all movements slowly. While you’re at it, do back leg raises. The method is the same, except you lift one leg behind you. Don’t lean forward though.