Mimi, my ob-gyn is in her forties, but she is a tri athlete, so she totally understands my lifestyle, which is more than i can say for my pcp. I used to see her at the gym at 5:30 AM! She also lost 160 lbs. a few years ago, and really pushes the healthy lifestyle bit on patients. One of my (overweight) friends stopped going to her because of it.
So don't rule out someone younger...