I used to moderate a "Senior Fitness Forum" which was quite active, and attracted some top-notch competitive athletes from across the country. But, it died a slow death. It is still there, but no one ever posts.
http://health.groups.yahoo.com/group...tness/messages
There is a fitness after 50 web page operated by Ed Mayhew. He wrote a book and Nora and I are in it as "Masters of Fitness
."
http://www.fitterafter50.com/