For me bike commuting and riding for exercise are different experiences. When I work-out I usually push myself much harder and am faster but also more tired in the end. I go to a more desolate country road or a bike path somewhere so that I dont have to deal with traffic, stopping, slowing down, etc. Commuting is more about riding when conditions aren't optimal, when I don't necessarily feel like it, when the weather is bad, when there's lots of traffic, in short it's more about testing myself There's no parking at work too, so unless I want to ride the stinky bus...