Why Not Just Walk?

One thing I'm enjoying about Couch to 5k is that it insists on a five minute walk before I start running. I enjoy walking, especially in this sunny weather.

I read the other day that running a mile burns the same number of calories as walking a mile. In other words, I could get the same results without half killing myself. In even more other words, what's the point of trying to run 5km when I can already walk it? 

Well, here are the answers:

1. Time. I can run a mile in ten minutes, but it takes me twenty minutes to walk it. In other words, I burn those calories in less time. When I run back from the morning school run I get home with a good five minutes to relax before I am due to start work (I work from home, 9-2). When I walk back I often open the front door to the sound of the office phone ringing. I'm usually pretty short on time, so being able to run buys me more.
2. Afterburn. Running raises the heartrate considerably, and that can burn an additional fifty or more calories in the half-hour after my run is over. I don't get that with walking.
3. It might not be true anyway. More recent research suggests that, in fact, running burns around 26% more calories for the same distance as walking. Studies are ongoing, so I shouldn't throw in the running towel just because the urban myth is that it doesn't make a difference which I choose.
4. I may claim to be running just for weight loss, but in fact the underlying reason I want to lose weight is because I want to be healthy. I want to lose weight so that I reduce my risk of heart attack, stoke and diabetes, so that I can be active without getting out of breath and so that I can improve my asthma and my general quality of life. Well, running gets me to those goals too. I am not running for weight loss, I am running and losing weight in order to be healthy.