Recently I added running to my exercise menu. While in San Diego last week, I got up one morning and starting jogging along the pier and just kept hugging the water's edge until I realized that I had run all the way from my hotel back to the airport -- which trip had cost $11 plus tip by cab! Of course, the cab driver couldn't take the same route I did, but still.

Running is a great choice while on the road -- especially when you're someplace like SD which provides such nice whether and beautiful scenery to run through. I mean, taking my bike with me isn't really an option, and I get pretty tired of stationery bikes, treadmills, and elliptical trainers in hotel gyms. Being outdoors is more fun, even in a city. Or maybe especially in a city. In some of the places I've stayed over the years, running would probably feel more like a survival thing than strictly a matter of ensuring fitness.

But the other reason for adding running is that I've observed lots more fat people riding bikes than jogging. Of course, that could mean a lot of things -- fat people start out riding bikes and then end up jogging, the fat joggers are all there but on a trail I don't use, people jog because they're thin and it doesn't hurt them the way it would heavier folks (as opposed to concluding that they're thin because they jog), etc. But I think it's also reasonable to assume that running might represent a somewhat more vigorous workout, or that metabolically, it might just be more effective at burning fat.

So I was very pleased with myself when, yesterday, I ran one of my suburban mountain-biking courses. The distance is hard to estimate, but it was somewhere between 6 and 8 miles, with lots of grueling uphill stretches, several highly satisfying downhill stretches, and very little flat ground: pretty much the opposite of the terrain on the San Diego waterfront, seeing as I didn't push on up the cliffs to La Jolla.

So let's call it 7 miles. That means that I did better than 10K, not bad for a beginner. I mean, you can't possibly run like that and keep much fat on your body, now can you?

Um, well, yes you can. Check out the September Scientific American if you get the chance. It's all about nutrition, obesity, starvation, metabolism -- all things food. One of the articles, Can Fat Be Fit? makes this observation:

Triathletes can now top 300 pounds, part of the fat-but-fit movement.

So people can be competitively engaged in an activity that has them swimming a mile, running 6 miles, and biking 25 miles and still look like this:

Not to say there's anything wrong with the way this guy looks, I'm just surprised that a person could do that much cardio exercise and still be so big. I tend to expect a story more like this one -- very similar to my own, with that starting weight of 297 pounds -- where people lose a bunch of weight related to improving their athletic performance. Per the Sci-Am article, there are those who argue that people should be focused on fitness, not weight loss. Our triathlete shown above would be an example of somebody who is achieving remarkable things athletically, perhaps all the more remarkable when one considers his size.

All of which leads me pretty much back to the same conclusion as last time: this stuff is complicated.