One of the problems I encountered this past week, only having one day to commute by bicycle, was the time I had to simply think about things. When you bike to work and back, there is this time without radio, without frustrating traffic, without...multi-tasking. I just pay attention to the bike, road, traffic and let your mind relax about everything else for the duration of the commute. It's got to be good for you. I have a much better day at work when I bike. Next week I should be back to 4 days bike commuting.