I get that myself. I have a congenital heart condition that doesn't affect me much (yet) but requires regular visits to a cardiologist to monitor. I usually ride my bike to the appointments. When I walk into the waiting room wearing my bike gear I'm met with incredulous stares from people hooked up to oxygen tanks wondering if I'd made a wrong turn.

The nurses aren't used to dealing with people like me (i.e. relatively young and healthy.) As part of their general script upon check-in they ask patients, "Do you feel well enough to walk, or will you need wheelchair assistance?"
Whenever they ask this I grin and hold up my helmet saying, "I rode my bicycle here, so I think I'm good."

When I was first diagnosed with my condition four years ago at age 42, my doctor told me that the reason I had gone so long without them realizing I was born with a heart defect was probably because of all the bicycling/exercise I've done. Had I not kept in good cardiovascular shape I'd have had open heart surgery by now. He tells me to keep riding like I'm riding and I can probably stave off surgery for quite a while. So on days I don't feel like riding, I can pull this reason out of my pocket for some extra motivation.