insert a tampon to help prevent urinary incontinence:
http://wetmatters.com/blog/2010/08/25/dealing-with-womens-urinary-incontinence-while-exercising
Tip #3: Use a Tampon or Urethral Insert
Both tampons and urethral inserts increase pressure on the urethra and support the bladder. Both of these actions can help prevent urine leakage during while you exercise, especially if you suffer from stress urinary incontinence.
http://wetmatters.com/blog/2010/08/25/dealing-with-womens-urinary-incontinence-while-exercising
Tip #3: Use a Tampon or Urethral Insert
Both tampons and urethral inserts increase pressure on the urethra and support the bladder. Both of these actions can help prevent urine leakage during while you exercise, especially if you suffer from stress urinary incontinence.