Normally, I am much more of a tortoise than a hare -- a long rather than a fast walker. So I wondered if I could walk at moderate intensity. I chose one of my favorite level trails, one that doesn't have a lot of rocks that would slow me down. While I took my camera as I always do on a hike, I determined not to use it unless I saw something extraordinary, and I didn't. I also didn't do any interval training, no jogging or running. I just walked at a comfortable speed, albeit faster than normal.

When my iPod told me that 30 minutes were up, I was pleasantly surprised that I had walked 3,190 steps. That's certainly moderate intensity and a level that I would not have achieved without this prodding.