Oh, but there are so many more lovely categories! I don't know about you, but I've done variations on all of the following (sometimes in the same race or outing): sprinting, shuffling, trundling, leaping, trotting, plodding, and my absolute favorite, waddling (after my first and only ultra).

Really, it's all about putting one foot in front of the other. I agree with the others: if you are more than casual about it, you're a runner.