You're a runner if...

... you keep shoes and running clothes in your car so that if you're ever on a trip and drive by a place thinking "it'd be great to run here..." you can get out and go for a run
... you sleep in your running shorts because they're more comfortable than pyjamas, not to mention you don't need to change for your morning training session
... you can correctly pronounce names like "Hicham El Guerrouj" "Kennesia Bekele" and "Haile Gebresilassie"
... you've found yourself running around an airport departure hall thinking, "if I can just get in three more miles, I'll meet my mileage target this week"
... you wear sandals despite having the ugliest feet in the world, along with several black toe nails
... you get upset and impatient when results from the race you ran aren't posted on-line by the time you get home
... you find a magnifying glass to see your name in the paper.
... you have chafing in strange places.

... you spend more on training clothes than working clothes.

.

(tbc)