The people that think it crazy are the ones who don't start an exercise routine because it's "too hard."

Hell, I mention that I've got a thirty-mile bike commute to work, and people look at me like I'm nuts. My response is usually something along the lines of, "But it's only thirty miles; there are tons of cyclists who consider that a warmup!"

Hell, besides, cycling is a hell of a lot more fun than sitting on a stationary bike at a gym; with the added benefit of being able to *go* somewhere[1]. Cycling also provides motivation for lazy bastards like me; about the point I'm thirty miles from home and just want to relax, I really don't have much of an option except bike the thirty miles home.

[1] Let's see, forty-five boring minutes on a Lifecycle, or an hour and a half of fun on my hybrid while I run errands around town...