I've only been commuting by bike for about a month or so, but I do have to get the train/car to work about 50% of the time, I go to customer site a lot and aside from the fact the distance is often 70 miles plus there would be no where to get washed up once I arrived. When I don't cycle it's just not the same, even after only a few weeks. There is nothing like being sat at my desk having head the blood pumping and knowing that I have got some good exercise in already And also nothing like being sat at a desk knowing that I would feel great if I had been on the bike.