1) Everything hurts. All the time.
2) You spend every waking hour eating, and you sleep like the dead.
3) It's like taking a part-time job. The closer you get to the marathon (and I'm only in week 5 of 16) the less of a social life you have.
4) Your abs look RIPPED, but all the just-for-show muscles you've built up to attract men start to shrink.
5) Your house is always draped with half-sweaty clothes.
6) You go through underwear twice as fast (see "sweaty clothes" in item # 5).
7) You discover that an icy cold soda -- no matter how delicious it sounds -- is not even remotely thirst-quenching.
8) "Runner's high" is a dirty LIE.
9) You learn pretty quickly which energy bars make you gassy.
10) It's hard to fart quietly when you're running.