That's true. But primarily I'd like to lose weight. I once had a commute that included a couple miles of walking. I lost significant weight because I was forced

That's true. But primarily I'd like to lose weight. I once had a commute that included a couple miles of walking. I lost significant weight because I was forced to do this (well, too cheap to take a cab or a bus). I've never been able to motivate myself to do that when I'm not forced to.