I started running in March 2008, after a lifetime of precious little physical activity. Call it a mid-life crisis: I decided that I wanted to live longer.

Worried about my back, I ran only on treadmills at first, fearing the high impact of street running. This got old pretty fast, so I switched to running on an indoor track. This worked fine but, like treadmill running, it necessitated a trip to the gym. It would be so much easier to just go outside and run!

So, wearing the best running shoes that I could find -- the Brooks Ariel, which were recommended by my podiatrist -- I began running the flats in my neighborhood. Alternating street runs with gym visits, I discovered two things: First, the street runs left my lower back sore each time; and second, the gym runs didn't leave me feeling very much better.

Then, one of the coaches at my college brought me this:

New research on barefoot running had made the cover story of Nature (January 28, 2010. For details and excellent video, click here: runbare.com

Briefly, Dr. Daniel Lieberman of Harvard University has demonstrated that barefoot runners are more efficient and less prone to injury than runners who wear athletic shoes. Simply put, runners in shoes land with all of their weight (plus gravity) on one heel with each stride, enduring an extreme shock each time. Barefoot runners, however, habitually land on the forefoot, in the area of the arch just behind the balls of the fourth and fifth toes. Running in this manner allows the 26 bones and 33 joints of the foot to effectively absorb and distribute the shock of each landing through the muscles of your feet and legs. Landing on your heels, however, delivers a sharp blow to a single bone which is ultimately transmitted through the leg to the pelvis and spine. Moreover, a barefooted heel-striker hits the ground with 7 times the impact of a barefooted forefoot-striker. Running shoes, invented in the 1970s, reduce the impact of the heel strike to about 3 times that of a barefooted forefoot strike. They also make a lot of money for Nike.

Dr. Lieberman makes many important points with his research but one in particular struck home with me: We evolved to run barefoot. As a professor of anthropology, this makes perfect sense to me. Of course we are adapted for barefoot running! Hard-soled shoes are a product of the industrial era; prior to that, people wore soft-soled shoes or none at all. The point is, you could feel the ground beneath you and react to it intuitively in a manner that protected your body. When you ran, you struck the ground with your forefoot rather than your heel simply because it hurt less. Running shoes are built to absorb the shock created by the heel strike; in other words, they compensate for the fact that we are wearing shoes in the first place! So why not take them off?

Clearly the answer has something to do with cut and blistered feet, and possibly even tetanus shots. Running completely barefoot? That's hardcore, even for me. I feel like I need a little something between me and the road, just for protection. Enter the Vibram Five Fingers.

Say what you like about them; I know they're ugly. I'm done with paying the price of fashion. And you know what? No more back pain.

Yes, the first few runs hurt like hell. Yes, I had terrible cramps in my feet, calves, and shins. Yes, I got blisters on my feet. But they toughened up pretty fast, and I tape them now to prevent blisters. All of the aches and pains were gone within three weeks.

The most amazing thing, however, is the new relationship that I'm building with my body. For a long time, I've taught my physical anthropology students that we humans, like all other primates, have extremely sensitive tactile pads on our fingers and toes. It's easy to see why we'd need such sensitivity in our fingers, but the toes have always been a mystery to me. Why would we humans, with our stiff-soled shoes, need to have sensitive feet? Now I know why: It's because we used to use them. We used to feel the ground beneath us and react to it; we used our toes for balance and the muscles of our legs to vary pressure along the foot.

As I was running the other day, I felt a large pebble under my left foot; instantly a muscle behind my left knee contracted involuntarily to prevent me from placing any weight on that spot. That's exactly what my body is supposed to do. Pretty cool, huh? It's wonderful to discover so late in life that my body actually knows how to protect itself.

Don't get me wrong; I don't expect to quit wearing shoes any time soon. I do, after all, live in 21st-century America. I also don't plan to start wearing those Vibrams all over the place. My wife says they make me look like one of the Na'vi. I do, however, plan to do all of my running in them. It simply hurts less.

Good running!