Stealth Exercise

I think one of the benefits of walking as a tool for fat loss is that you can do a lot of it "under the radar".  By this I mean that you can perform a large volume of walking without 1) stimulating hunger, and 2) overtraining and setting off the body's alarm system.

For example, if I walk an hour it really doesn't increase my hunger much, and it doesn't lead to a huge increase in my daily caloric intake.  In comparison, when I ran my one-and-only marathon years ago, the training made me ravenously hungry.  After I would run 12 or 15 miles, I would be hungry for days; it was as if I couldn't get enough food in. 

I actually gained weight during my marathon training.  Even though I was doing a large volume of aerobic work and burning lots of calories, I took in even more calories due to the hunger.  I think my body switched into survival mode, trying to gather as many calories as possible and hoarding them in the form of fat storage.

You can look at this process from a hunter-gatherer viewpoint.  If a hunter-gatherer is having to walk more than usual to find food, more calories are being expended for food procurement than are being taken in, and hence the body will burn some stored fat. 

In comparison, what would drive a hunter-gatherer to run 12, 15, or 26 miles looking for food?  Times must be pretty tough if you have to work that hard for some food.  Hence, the body may read this situation as an emergency, driving the person to eat more and ultimately store more body fat.

I see similarities to this in terms of modern training methods.  I've read many times where people start an exercise routine and blast their body with lots of weightlifting and lots of running, yet they do not lose any weight.  Walking is more of a ho-hum method for weight loss.  It's not as exciting as other forms of exercise, but it gets the job done.