Susan, you don't need to be training for an event to be a "serious" athlete. Your lifestyle most certainly qualifies as "serious." The same way I would put myself in this category. I do think medical people have difficulty envisioning this lifestyle, especially if they are more casual exercisers or extremely competitive.
As far as the the doctor visits, what I mentioned before is pretty much my visits to my pcp. I go to the dentist 4X a year, as both of my parents had pretty bad periodontal disease and I was going in that direction. This has helped get it under control greatly. I get a mammogram yearly, and a bone density scan, as osteoporosis is the only real "thing" I have, other than allergies/asthma. I see the endocrinologist a couple of times a year, for tx of the osteoporosis.
I spent most of 2007-2008 going to various specialists to diagnose my mysterious pain, tingling, headaches, stomach issues. Although I ended up under the care of a rheumatologist for fibromyalgia, there really was no definitive diagnosis. I may have a mild presentation of the disease, as I never had the cognitive symptoms. Because of this experience, I know my body a lot better and now know the pattern of what happens if I am over training, stressed, etc. I also don't run to the doctor as much. But, my tipping point is if I think I might have bronchitis or if my asthma is acting up because of a cold or sinus infection. My asthma is 100% better and under control than it was 20 years ago, so I do not ignore that.