The muscle that supports the vagina, the pubococcygeal (PC) muscle, may become lax with age as well as with childbirth. You can strengthen your PC muscle with Kegel exercises. To learn how to perform Kegels, sit on the toilet, legs spread. Begin to urinate, then squeeze your pelvic-floor muscle to stop the flow of urine. You have now identified the PC muscle and can squeeze and release it anytime.