In regards to what Bruce mentioned, I truly believe that aikido should be available to people of many different abilities. This article is by a friend and fellow practitioner in Aikido. He's 61 years old and the recipient of a transplant. He has been training in aikido for over five years, now. And is currently ranked 2nd kyu. I took his ukemi for his test this past November. Maybe one day Bruce, you will see Ed test for his shodan at the USAF Winter Camp. Here's his story. He's truely an inspiration.
In regards to one's physical health, I do believe that anon's friend mentioned that anon wanted to take up aikido to help build her strength. There is nothing wrong with that. I have found from my experience that obesity was a choice not a disability. If someone doesn't have a choice, that's one thing. My obesity was affecting my aikido training so I decided to do something about it. By strenghtening my muscles, I can better protect my joints. By improving my flexibility, I have a greater range of motion. By working my core muscles, I protect my back. By losing weight, breakfalls don't hurt. No, I can DO THEM NOW. When I started aikido, I was very much "into" the spirituality of it all, but through my training and being very physical I have been able to touch a part of my self that I never would have otherwise. My physical is spiritual. The physical path is my path, so please don't knock it.