As with any muscle strengthening, any initial improvements seen (i.e., in the first one to two weeks) are usually due to motor control changes, through improved efficiencies in the messages from the brain to the muscles. True changes in the size and number of muscle fibres is often seen by six weeks, when most people notice some improvement in pelvic floor symptoms. It can take three to six months to see a major change and often when completing a pelvic floor strengthening program after childbirth, small improvements in strength can continue to be seen up to one to two years post-delivery.