Women are being urged to take regular exercise to ward off the threat of incontinence.
Many women suffer from a condition known as stress incontinence.
This is caused by a weakening of the pelvic floor muscle, which leads to a loss of bladder control.
The problem can become so severe that some women suffer from incontinence when they laugh or sneeze.
The pelvic floor muscle, which is attached to the spine and the pelvic bones, acts as a sling, bearing the weight of the organs above it, including the bladder.
It stretches to accommodate pressure, and returns to its original shape once the pressure is relieved.
However, if too much strain is put on the muscle, it can weaken and become ineffective.
A pilot study of teenage girls has shown nearly half of them had a problem with incontinence.
Even fitness instructor Simone Price suffered from a weak pelvic floor muscle.
She said: "I look after myself, but I can honestly say I did neglect that muscle group.
"You just think it is going to look after itself.
"I'm not that old, and to admit you have got a problem with leaking is quite a thing to admit."
Part of the problem is that many people fail to take in the correct amount of fluid each day.
Drinking too little fluid can cause just as many problems as drinking too much.
Many people try to combat incontinence by cutting down on their fluid intake, but this can lead to very concentrated urine, which can irritate the bladder and exacerbate the problem.
Study author Julia Herbert, from Bolton Community Trust, said both men and women should drink between one-and-a-half and two-and-half litres a day.
Surgeon John Osbourne, of University College Hospital, sees thousands of women every year with pelvic floor muscle problems.
He believes surgery should be a last resort.
He said: "I only operate on about half the women I see, the rest we can help in other ways.
"Any operation for incontinence does not return the pelvic floor to the way it was before it was damaged.
"Most women do not think about their pelvic floor until something goes wrong with it.
"It would be an advantage if women knew more about their pelvic floor early on in life, so that they could treat it well and exercise their pelvic floor muscles."
It is important that women take regular exercise to keep the pelvic floor muscles in trim.
The muscles that need to be exercised are those that, when contracted, halt the flow of urine in mid-stream.
There are various devices available to help with pelvic floor exercises.
These include a weighted vaginal exercise cone that is made of plastic and is hollow so that it can be built up gradually with weights.
For more information contact the Continence Foundation Helpline on 0171 831 9831.
An item on pelvic floor muscles will be featured on BBC Two's "Trust Me, I'm A Doctor" programme. Friday 26 February 2000 GMT.