By Dr. Mercola
A number of runners who believe barefoot is best may be surprised to learn that a new study shows they may not be getting the boost they thought they were from going without shoes.
Researchers at the University of Colorado say what's really best is running with lightweight, cushioned shoes, which do a considerably better job at conserving a runner's energyi – but the matter is still up for debate.
Is it Easier to Run While Wearing Shoes?
The study involved 12 experienced runners who had "extensive" barefoot running experience. They ran on treadmills on different occasions, wearing either lightweight, cushioned running shoes, or no shoes (rather than being completely barefoot, they wore thin yoga socks). During the barefoot running sessions, the researchers taped small weights to the top of the runners' feet to simulate the same amount of weight as wearing a shoe.
What they found was that barefoot running used nearly 4 percent more energy with every step, which suggests it may be physiologically easier on your feet to wear lightweight shoes. The difference came in, according to researchers, because of the lack of shoe cushioning. This put the entire force of impact with the ground on the leg muscles, which had to work harder when barefoot compared to with shoes.
So, metabolically speaking, it may be more efficient to wear lightweight (about 150 gram) shoes – but whether this actually translates into being able to run farther or faster for the average runner remains to be seen. It should be noted that the shoe used in the study was the Nike Mayfly, which is designed to be particularly lightweight and is not the type of running shoe most casual runners wear. Furthermore, the study has run into some heated debate over several potential issues …
Critics Point Out Potential Flaws …
Humans have been running barefoot, or close to it, for ages; running shoes were only invented in the 1970s. Proponents of barefoot running suggest that not only does the lack of a running shoe save precious energy (as added shoe weight increases your energy expenditure), but emerging research suggests modern running shoes, with their heavily cushioned, elevated heels, may actually encourage runners to strike the ground with their heel first, a move that generates a greater collision force with the ground, leading to an increased potential for injury.
The featured study did not evaluate injury rates, but past research reviewed by Michael Warburton, a physical therapist in Australia, revealed: ii
- Running-related chronic injuries to bone and connective tissue in the legs are rare in developing countries, where most people are habitually barefooted
- Where barefoot and shod populations co-exist, as in Haiti, injury rates of the lower extremity are substantially higher in the shod population
- Wearing footwear actually increases the likelihood of ankle sprains, one of the most common sports injuries, because it either decreases your awareness of foot position or increases the twisting torque on your ankle during a stumble
- One of the most common chronic injuries in runners, planter fasciitis (an inflammation of the ligament running along the sole of your foot), is rare in barefoot populations
- Running in bare feet reduces oxygen consumption by a few percent
There were also several direct points about the feature study brought up by barefoot running enthusiasts, which deserve further attention:
- The runners were said to be "experienced" in barefoot running, but reportedly this only meant they had to have run barefoot or in "minimal running footwear" for at least three months in the last year. It stands to reason that the more experience a runner has, the more efficient and the better form they will have, and three months may not be nearly enough to achieve proper barefoot running technique.
- The study used a treadmill, which is different than real-world conditions.
- The barefoot runners had weights taped to the tops of their feet, which is different than wearing a running shoe, which distributes weight evenly below your foot. This alone could have made their running more difficult. The barefoot runners also wore socks, which could also alter the true barefoot running experience.
An Often-Overlooked Benefit of Going Barefoot: Grounding
Whenever you go barefoot, you get the benefits of grounding with the Earth (an activity that is also known as "earthing"). The Earth is negatively charged, so when you ground, you're connecting your body to a negatively charged supply of energy. And since the Earth has a greater negative charge than your body, you end up absorbing electrons from it through the soles of your feet. The grounding effect is, in my understanding, one of the most potent antioxidants we know of and may have an anti-inflammatory effect on your body.
As written in the Journal of Alternative and Complementary Medicine: iii
"It is well established, though not widely known, that the surface of the earth possesses a limitless and continuously renewed supply of free or mobile electrons as a consequence of a global atmospheric electron circuit. Wearing shoes with insulating soles and/or sleeping in beds that are isolated from the electrical ground plane of the earth have disconnected most people from the earth's electrical rhythms and free electrons.
… A previous study demonstrated that connecting the human body to the earth during sleep (earthing) normalizes the daily cortisol rhythm and improves sleep. A variety of other benefits were reported, including reductions in pain and inflammation. Subsequent studies have confirmed these earlier findings and documented virtually immediate physiologic and clinical effects of grounding or earthing the body."
Since so few people ever walk (or run) barefoot anymore to experience the benefits of grounding, it is very plausible that some of the people who have converted to barefoot running are experiencing benefits not only from the lack of shoes, but also from the increased connection to the Earth.
Barefoot or With Shoes: Do You Have to Choose?
It's likely that there are benefits and risks to both shoe-wearing and going barefoot, and you can tailor your footwear (or lack thereof) decisions accordingly.
For instance, if you'll be running on asphalt or rocky terrain, or in very hot or cold temperatures, a lightweight shoe makes sense to protect your feet from injury (seasoned barefoot runners note that the skin on the bottom of your feet naturally thickens the more time you spend without shoes, offering natural, built-in protection, but this will take time to build up). For times when you'll be on softer surfaces, such as sand, grass or a dirt path, try going barefoot and see how it feels.
Do use caution when first starting out, as many new barefoot runners continue to land heavily on their heels -- and the result can be injury. When running barefoot, you need to aim for a forefoot or mid-foot impact with the ground, which will take some adjusting to. If you decide to give barefoot running a try make sure you do it slowly, progressing gradually to more and more time spent without shoes. Listen to your body and go from there …