Originally Posted by Cyclaholic

There's a difference between a friendly coworker joking around with you and a belligerent one insulting you for your chosen mode of transport. Only we as individuals are in a position to make that distinction.

I've had a quite unfit and overweight coworker ask me why I don't drive like "normal" people, my response was along the lines of "please don't die of your first heart attack, that way you can continue to serve as an example of why I choose to ride my bike... heck, you might even wise up too!".