I am not in wicked good shape. I'm 49 years old. Ninety minutes of ice skating Friday with my kids had my abs sore for three days, as an example.

The bike commuting is a weird workout. I don't try to exercise or go fast. I focus on safety, durability, and getting to work reliably. I don't stand up. I don't press hard on the cranks. I protect my knees and my body. I'm generally not even breathing hard.

I also don't do any other kind of exercise, so whatever workout I get is far from balanced.

I do burn a lot of calories. Plan on taking some of the gas money you save and sinking it into large packages of whatever it is you plan to eat.