Sports specific training

It goes without saying that certain physical activites encourage pelvic floor activation and recruitment, others hinder it, and yet others totally ignore it!

The eternal debate - is she a dancer because she has the right physique, or is her body so slender and strong because she is a dancer?
The answer? A bit of both (balance). Dancers tend to come from the physically gifted - co-ordination, core stability, flexibility, strength, rhythm, timing, control, fitness, body fat, power/weight ratio... they've got it all. But it is without any doubt that the dancing itself helps to maintain the dancer's body, a finely tuned instrument.

Weight lifting is particulary damaging to the pelvic floor, especially if no effort is made to contract the pelvic floor with each lift. Weight belts, which encouarge bracing against the belt for additional support, are the worst offenders. If you can't use your own core strength to support the spine and internal organs, should you really be liting it in the first place, as an exercise? What about less weight, greater control - less bulk, better definition...

More than 70% of female runners (with children) suffer from stress incontinence

Runners... sigh. Never tell a runner not to run....
Long distance running can place considerable repetitive 'slap-slap-slap' downwards stress on the pelvic organs. It can also tire the pelvic floor, so it is less supportive (usually due to fatigue) at the exact time when you want it to be functioning optimally!
Downhill running can be very jarring, as the knees always let you know... The added heel strike increases the demand on the pelvic floor. And the additional weight transfer jiggles the internal organs merrily!
Mums who are planning to run marathons should get their pelvic floors 'checked and cleared' or get appropriate treatment to improve insufficient muscle activity.
Vaginal inserts exist; placed in the vagina they provide some extra internal support. (A superplus tampon would have a similar effect.)