I started riding my bike to and from work a couple of months ago. It's about 4-5 miles one way, 15 to 20 minutes on the bike. The first thing I noticed was that I was in much better shape. I was never in bad shape, but when you're over 40. . . . . Then I noticed that my clothes were getting bigger. I figure I've lost a couple of inches around the waist (never had many to lose to begin with) without even trying. No change in diet, eating habits, etc. I can recommend riding your bike to work for anyone who wants to lose weight or get fitter.