Bill Gates is 58 years old. "Once you get fit" takes on a whole new meaning once you pass 40 -- it gets a lot harder and you run into musculoskeletal and joint

Bill Gates is 58 years old. "Once you get fit" takes on a whole new meaning once you pass 40 -- it gets a lot harder and you run into musculoskeletal and joint problems that seldom affect folks who haven't hit middle age yet. Cycling's probably not a big deal if the area you live is flat as a pancake, like the Netherlands, but Seattle is anything but flat. (I speak from 49 years of life experience. Exercise means swimming for me: getting myself run over or requiring titanium knees are not on my to-do list for the next decade.)