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The benefit of running barefoot has
recently received a large amount of media
exposure.. Arthur Lydiard the
legendary New Zealand coach preferred his
athletes to run barefoot. The eccentric
Australian coach of Herb Elliot, Percy
Cerutty got his athletes to train barefoot in
the sand dunes of Portsea, Victoria. These
claims are all well and good, but is there
any scientific evidence to support them?

Force Differences
It has been stated that the primary aim of
running shoes should be to reduce impact
forces following heel strike. However,
research studies comparing barefoot
running to running in shoes have found
that the impact force peak is either equal to
or lower while running barefoot. These
results have also been supported by studies
looking at forces in running shoes with
very hard, standard and soft soles. The
propulsive force experienced in the final
stages of ground contact when you are
preparing for the fight phase of running is
also lower while running barefoot. This is
the reverse of what would logically be
assumed. The reason behind this is that
runners, while running barefoot, make
consistent changes to their running
technique. One theory is that when
landing on a soft surface people land
harder to improve their stability.
Running shoes do however increase the
time taken for the initial force peak to be
reached. During barefoot running the
initial force peak occurs very rapidly,
between 4.8 and 14 milliseconds (ms),
after the foot makes contact with the
ground. With shoes, this time is increased
to about 30 ms. This increased time to
peak force is an important function of
cushioning, as the body is better at
compensating for gradually applied forces
and it is believed that this increase in time
taken to reach the impact force peak is
what provides the perception of
cushioning.

Pressure Changes
Pressure is a ratio of force per area.
Therefore, pressure can be low if force is
spread over a large area. In-shoe pressure is
possibly of more interest than force when
investigating the cushioning properties of
shoes as it allows for the measurement of
loads on specific foot structures. Unlike
force, pressure is considerably decreased in
running shoes. Running shoes also partially
absorb the extra pressures created by foot
malalignment (eg high arched feet). This is
important, as high pressure has a direct
correlation with foot pain. It is understood
that an increase in contact area with the
soft shoe conforming to the foot is
responsible for the decrease in pressure
rather than a decrease in force, because as
mentioned earlier we know force peaks are
not reduced by cushioning.
Technique Differences
While running at the same speed, people
running barefoot have a flatter foot
placement. It is thought this is a
mechanism to protect the heel of the foot
and the body from high impact. It also
allows the calf muscles to control the
Written by Caleb Wegner
Barefoot Running
The truth behind the hype
One of the most famous barefoot runners
of recent times, Zola Budd, competing in
the 1986 World Cross Country Champs.
Run For Your Life
Getty Images
Barefoot 9/1/06 10:10 AM Page 10
lowering of the heel to the ground
increasing the time in which the force is
applied to the body. This has been backed
up by other research that has found
midfoot strikers do not have an initial force
peak and have lower overall forces. People
running barefoot also have a greater rate
and amount of knee flexion (bending).
This acts as a big shock absorber and
increases the time in which the force is
applied. Runners running without footwear
also have a shorter stride length; higher
stride frequency (faster turnover) and a
shorter ground contact time. These changes
all assist in the reduction of the force
peaks.

One particularly interesting study
investigating pronation (when the foot rolls
inwards) and other foot motion when
barefoot and in shoes was undertaken in
Sweden using bone pin markers. They
found that the motion of the heel and
lower leg bones was not altered by footwear
with support on the inside of the foot. This
has been backed up by other research that
has also found that the speed and total
amount of pronation is lowest while
running barefoot. While the motion of the
bones may not be reduced in footwear, it is
thought that supporting the foot during
this motion may help reduce symptoms
caused from excessive motion.

Foot Muscle Strength
There is limited research into the claims
that barefoot running increases the strength
of foot muscles. One study recently funded
by Nike and undertaken at the University
of Cologne looked at foot muscle strength
in runners that went barefoot
while warming up. They found over a fivemonth
period that the strength of toe and
foot muscles was increased by 4-5% but
not muscles in the calf. This extra foot
strength may assist in controlling excessive
motion in the foot but there is not yet any
evidence for this.

Injury Rates
The claim that barefoot running results in
a reduction in injury rates has legitimate
basis. Running injuries are generally
categorised into two types, those caused by
excessive repetitive forces or those caused
by muscles trying to reduce excessive
motion. As shoes do not reduce force or
motion in the foot, this could theoretically
result in a reduction in injuries for barefoot
runners. Unfortunately, there is no
evidence to support this hypothesis.
However, an unprotected foot opens up a
completely new type of traumatic injury.

Before the Nikes, before the breathable, antimicrobial running shorts, before the personal fitness coaches, heart rate monitors, wrist-mounted GPS and subscriptions to Runner’s World, you were a runner.

And, like all children, you ran barefoot.

Now, a small but growing body of research suggests that barefoot is the way adults should run, too. So, many runners have been shucking off the high-tech trainers in favor of naked feet — or minimalist footwear like Nike Free, the Newton All-Weather Trainer and the glove-like Vibram FiveFingers.

“People have been running barefoot for millions of years and it has only been since 1972 that people have been wearing shoes with thick, synthetic heels,” said Daniel Lieberman, a professor of human evolutionary biology at Harvard University.

Strong evidence shows that thickly cushioned running shoes have done nothing to prevent injury in the 30-odd years since Nike founder Bill Bowerman invented them, researchers say. Some smaller, earlier studies suggest that running in shoes may increase the risk of ankle sprains, plantar fasciitis and other injuries. Runners who wear cheap running shoes have fewer injuries than those wearing expensive trainers. Meanwhile, injuries plague 20 to 80 percent of regular runners every year.

But the jury’s still out on whether going barefoot is actually an improvement.

“The running shoe right now is doing nothing for preventing injuries,” said Reed Ferber, director of the Running Injury Clinic at the University of Calgary’s Faculty of Kinesiology. But, he adds, going barefoot has downsides too, and the research so far is still inconclusive. “It’s a total tradeoff.”

Chris McDougall, author of the recent book Born to Run, goes further. “If this were a drug, it would be yanked off the market,” he said of running shoes. McDougall says his own persistent problems with plantar fasciitis cleared up after he started running in Vibram FiveFingers.

What’s so great about going shoeless? It allows the foot to flex and absorb shock, says Tony Post, president of Vibram USA, which makes FiveFingers. With thick heels, people lengthen their strides, landing heel-first and letting the shoe absorb the impact of each footfall. You can’t do that barefoot (try it sometime), so your body naturally falls into a shorter stride, landing first on the outside middle or ball of your foot. As you advance your foot rolls inward; the arch flattens and helps absorb the impact; it then springs back up as you lift your foot and push off the ground.

“In a sense the arch is acting like a leaf spring,” says Post.

Lieberman’s research into human and early hominid fossils suggests that the human body, including the foot, is well-adapted to long-distance running without shoes (.pdf). He hypothesizes that early humans didn’t need speed so much as endurance — just enough to run down herd animals like kudu or eland until they collapsed from overheating.

This so-called persistence hunting is not as hard as it sounds, Lieberman says. “You can be a middle-aged professor like me and still be a good enough runner to have been a fairly successful hunter in the Paleolithic.”

He’s sure that running barefoot or with minimal footwear is the way to avoid injury. After all, we evolved without shoes.

“If a third of runners had gotten injured in the Paleolithic with runner’s knee or plantar fasciitis, you can bet that natural selection would have weeded them out,” Lieberman says.

Ferber is more cautious. His studies of the biomechanics of running show that a midfoot strike does reduce the initial peak loading force — the impact in the first 25 milliseconds after your foot touches the ground. But your foot sustains a second peak load of three times your body weight about 100 milliseconds later, regardless of whether you’re a heel-first or midfoot-first runner.

“So it’s six of one, half dozen of the other, in that you’ve lost that first peak, which is maybe a good thing,” says Ferber. “But in order to do that midfoot strike, you have to take a shorter stride, so you’re taking more steps per mile. So that could cause injuries.”

Ferber does note that knee osteoarthritis rates are very low in China, where many people wear flip-flops (which also encourage a midfoot strike), and that studies have shown women who wear high heels are at increased risk for knee osteoarthritis. That research doesn’t address running specifically, however.

As for efficiency, Ferber’s studies suggest a midfoot strike might be about 1 percent more efficient — but that’s within the 2 percent error rate of the sensors used to measure human body force, so it’s a wash.

Both Ferber and Lieberman are in the midst of long-term studies aimed at producing more conclusive data about injury rates and efficiency of barefoot or nearly-barefoot running. Ferber’s lab is sponsored in part by SOLE, a shoe orthotics company, while Lieberman’s research is sponsored by Vibram.

The Vibram FiveFingers seem to have a special attraction to geeks, for whom claims of efficiency and scientific research resonate especially well. Silicon Valley entrepreneur Tim Ferriss wrote about the FiveFingers recently, calling them “nothing short of spectacular” in a blog post filled with technical and biomechanical references.

“For me the appeal is the radical minimalization of technology to serve its purpose (conditioning) better,” said Boston-based software designer Glenn McDonald, a self-described “not-very-serious runner” who wears FiveFingers on occasional runs.

As a nerd and a runner myself, I could hardly let these claims go untested. So for the past month, I’ve been running once or twice a week in the Vibram FiveFingers KSO model, with occasional stints done completely barefoot.

Following the advice of experts like Ferber and Barefoot Ken Bob, I started out gradually. To kick things off, I stopped in the middle of a four-mile run one dewy June morning, took off my running shoes, and did a half mile completely barefoot on a smooth, graded dirt path. It felt great, like getting a foot massage on the run. But my tender soles were stinging by the time I was done, and continued to sting for the rest of the day.

My second barefoot run, on asphalt, went more poorly: I tore up the tip of my fourth toe on the rough surface and spent the rest of my (shod) run bleeding into my sock. That was enough to make the attraction of Vibram’s foot gloves clear: They give you much of the feeling of running barefoot, and give the same workout to your arches, Achilles tendons and calves — except you don’t have to worry about injuries from rough terrain.

But by the end of the third week I’d worked up to three or four miles in the VFFs and nearly a mile at a time barefoot. My feet got tougher, but were still happier with the rubber covering, especially on rocky ground and asphalt. Each run felt better than the last, though it’s clear that my calves and my Achilles tendons in particular are not used to this kind of a workout. I suffered from sore tendons and, after one longer run, a sore ankle.

That’s a common problem among runners who transition too quickly to barefoot or minimal footwear, says Ferber. He’s seeing many runners jump too enthusiastically into minimal footwear and develop plantar fasciitis as a result.

“Runners are insane — they don’t like to accommodate, they just like to do,” Ferber said.

The key, Ferber says, is to build up ankle strength, transition slowly, and keep barefoot running — like other really taxing parts of training, such as hill work or speed work — to just 10 percent of your overall regimen. (See sidebar.)

Despite the soreness, I enjoy running barefoot — or nearly barefoot. I’m building foot and calf muscles I never know I had, More than that, it just feels fun. And, truth be told, I enjoy the puzzled looks from the people I pass on the trail and the coworkers I terrorize with my freaky rubber gorilla feet.

“We’re designed for persistence hunting, which is a mix of running and walking,” says McDougall. “What’s built into that kind of running is a sense of pleasure. You are designed and built and perfect for this activity, and it should be enjoyable and fun.”

So, like other nerds, I’ll probably keep happily running in the Vibrams, while eagerly awaiting the results from the next running shoe study.

As more than a dozen world records sank in the pool week with the help of new swimsuits that produced blisteringly fast times, one sport has turned its back on technology and is returning to basics.

High-tech equipment has reshaped many sports, but running has come full circle.

A growing band of runners have cast off their expensive and advanced shoes and are going barefoot, with recent research saying this is the key to performing best.

Physiologists say running barefoot helps athletes rediscover primal ‘‘running mechanics’’, the sort of techniques that have allowed members of some tribes to run hundreds of kilometres, apparently without fuss.

And even the multibillion-dollar sports-shoe industry has bought into the theory, with Nike crafting a minimalist shoe that mimics the barefoot running experience.

The shoe is promoted with the slogan: "Run Barefoot".

The celebration of the strength of the bare foot is a drastic about-face for an industry that, over a few decades, turned the simple sports shoe into an advanced piece of equipment - featuring air cushions, layered rubber soles and gel filled capsules - worth hundreds of dollars.

But Nike was forced into creating its minimalist shoe - Nike Free - after two sales representatives were shocked to find the Stanford University athletics team, whose runners it sponsors, running about barefoot, according to a recent book on running called Born To Run.

When the Nike pair asked why, Stanford’s head coach of athletics Vin Lananna said: ‘‘I can’t prove this ... but I believe that when my runners train barefoot they run faster and suffer fewer injuries."

Lananna’s instinct was echoed by research pointing out that the human foot - with its 26 bones and more than 100 muscles, joints and ligaments - was naturally designed to support running. But the modern sports shoes, with all its cushioning, prevented it from performing naturally.

‘‘A lot of foot and knee injuries currently plaguing us are caused by people running with shoes that actually make our feet weak, cause us to over-pronate [ankle rotation] and give us knee problems,’’ Daniel Lieberman, Harvard University professor of biological anthropology said recently in the Daily Mail.

‘‘Until 1972, when the modern athletic shoe was invented, people ran in very thin-soled shoes, had strong feet and had a much lower incidence of knee injuries.’’

Australian Institute of Sport senior physiologist Philo Saunders said that, while running shoes were initially developed to ‘‘support and cushion and reduce the risk of injury’’, the idea had become so ‘‘over-produced that runners became reliant on the shoes protecting them [and let their running styles deteriorate] ... causing more injuries than preventing them’’.

A series of injuries prompted Born To Run author, former war correspondent Christopher McDougall, to travel to Mexico to observe the barefoot technique of the Tarahumara tribe, known to be terrific long-distance runners.

‘‘They just stroll to the starting line, laughing and bantering, and then go for it, ultra-running for two full days, sometimes covering over 300 miles, non-stop,’’ he wrote.

But researchers found barefoot running contributed not only to a reduction in injuries, but also more efficient running.

At Nike, researcher Jeff Pisciotta - asked to study barefoot runners after those two Nike sales reps reported back from Stanford University - saw a radical transformation in the role of the foot in barefoot runners.

‘‘[Pisciotta said that] instead of each foot clomping down as it would in a shoe, it behaved like an animal with a mind of its own - stretching, grasping, seeking the ground with splayed toes, gliding in for a landing like a lake-bound swan,’’ McDougall wrote.

A Sydney podiatrist, Caleb Wegener, also noted barefoot runners had a flatter foot placement, with less heel impact and more bending of the knee.

‘‘Runners running without footwear also have a shorter stride length; higher stride frequency [faster turnover] and a shorter ground contact time,’’ he wrote in running journal Run For Your Life.

Various professional runners over time have relied on barefoot running for maximum performance.

In the 1984 Olympics, South African-born Zola Budd ran barefoot for Great Britain and went on to win the 1985 and 1986 World Cross-Country Championships. She set a world 5000-metre record without shoes.

In the 1950s, the late Percy Cerutty, who coached 1960 Olympic champion Herb Elliott, had his athletes train barefoot in the sand.

Local runners have incorporated barefoot running into their training programs in a bid to improve their performances.

‘‘A lot of people will do barefoot running in warm-ups if they’re on grass, just trying to improve muscles in the lower legs,’’ said Saunders, also a middle-distance runner. He finished fifth in the 1500-metre event in this year’s national athletics championships.

‘‘You have more elastic energy, it’s a bit more bouncy, so there’s better economy of running. Overall it means better running mechanics and the training benefits translate into performance benefits.’’

He said the AIS had no formal policy for adopting barefoot running, but most coaches and athletes were conscious of the benefits.

‘‘There an awareness and collaboration with researchers to get ideas like this and structure it into their training program.

‘‘If you’re running better [barefoot in training], you are probably going to run better in shoes as well.’’

But he did not think runners would compete barefoot.

‘‘Most people will still compete with spikes on a track or road, with the spikes you get extra traction which allows you to go faster.’’

Many runners have switched to barefoot running for relief from chronic injuries. The human foot evolved without padded shoes. The structure of the foot and lower leg is very efficient at absorbing the shock of landing and turning the energy of the fall into forward motion, through the springing action of the foot's natural arch. It is only by placing large amounts of padding under the heel that humans are able to land on the heel rather than the ball of the foot. In doing so, the foot's natural motion is impeded and the arch and lower leg are not able to absorb the shock of the landing. Instead, the shock is sent up through the heel, to the knees and hips.

Barefoot running involves pushing from the ground with the ball of the foot rather than the heel, foot landing directly under the hips. "The force to drive you forward should only be applied after the foot has settled on the ground completely. Striking the ground, especially with the heel, causes trauma and makes the runner susceptible to injury." It follows that running shoes with heavily padded heels will impede this natural motion. Although there is much research to still be done, there are many studies that suggest that running shoes contribute greatly to the high incidence of injuries among shod runners.

Michael Warburton's 2001 review of barefoot running in the journal Sports Science concluded that

Running barefoot is associated with a substantially lower prevalence of acute injuries of the ankle and chronic injuries of the lower leg in developing countries, but well-designed studies of the effects of barefoot and shod running on injury are lacking. Laboratory studies show that the energy cost of running is reduced by about 4% when the feet are not shod. In spite of these apparent benefits, barefoot running is rare in competition, and there are no published controlled trials of the effects of running barefoot on simulated or real competitive performance.

This study reviews much of the scientific literature that connects shod running to both acute injuries, such as ankle sprains, and chronic injuries, such as plantar fasciitis, Achilles tendinitis, shin splints, etc.

In their article entitled "Is your prescription of distance running shoes evidence based?" in the British Journal of Sports Medicine, Craig Richards, et al.,^[6] determined that there is no evidence to support wearing "distance running shoes featuring elevated cushioned heels and pronation control systems tailored to the individual’s foot type." Richards found no studies published in peer-reviewed scientific journals that showed that running shoes either reduce injury rates or improve performance. In fact, Richards issued this challenge to running shoe manufacturers: "Is any running-shoe company prepared to claim that wearing their distance running shoes will decrease your risk of suffering musculoskeletal running injuries? Is any shoe manufacturer prepared to claim that wearing their running shoes will improve your distance running performance? If you are prepared to make these claims, where is your peer-reviewed data to back it up?"

Also from the British Journal of Sports Medicine, S Robbins and E Waked's article, entitled "Hazard of deceptive advertising of athletic footwear"^[7] described their study of the effect on a runner's foot strike of the runner's perception of how much padding there was under the foot. The more cushioning runners believe to be under the foot, the harder they strike.