The main message you should get from The Accidental Athlete by John "The Penguin" Bingham is that anyone can be an athlete; the term "athlete" comes from your own perception and efforts. Walk, run, cycle, swim, lift, jump rope, pole dance, skateboard, roller blade, play tennis, whatever! Just move your ass while doing something you actually enjoy.
Speaking of prying the butt cheeks off the couch, I think the most inspiring thing is that he started running marathons in his forties, after being over-weight, inactive, and a smoker for many years. Age, size, and history is not an excuse, people.
And that's it.