Faking it but raking it in

I have run a few marathons but the last one I tried was in 1996- more than twelve years ago. So I cannot claim, within reason, to be a marathon runner. However, years of practice have made me run efficiently, so observers get fooled by the style. This morning, as I was running a little uphill, an older gentleman who was bicycling was behind me. Eventually he came near me and said hello.
The conversation went as follows:
He: Are you training for a marathon?
I: No, I have done my share of marathons. I am just going out for an easy run.
He: You do look like a marathon runner.

And then, this encounter ended, like others, with each one of us going our own way.