[natrius2]

I can't recommend this enough. I'd lost weight before, but could never keep it off. Biking helped me sustainably lose 30 pounds. I also get to be even more smug than Prius owners.

The downside is that my car doesn't start anymore because I never use it.

[WalkingDead]

Watchout biking. It may cause impotence. Not joking.

http://healthlink.mcw.edu/article/1023994375.html

That was the first link from google. There are others more informative. Make a few searches if interested.