Barefoot running - new evidence, same debate
January 30th, 2010
A new study that will reignite the barefoot vs. shoe debate, one of the more controversial issues in running, is discussed by Dr. Ross Tucker, exercise physiologist trained by world-renowned running guru, Dr. Tim Noakes.
The following is an exerpt from "The Science of Sport."
The paper is called Foot strike patterns and collision forces in habitually barefoot versus shod runners, and it is published in Nature (Full reference: Lieberman et al., Nature, 463, 531 - 535).
The scientists took five group of runners and had them run both barefoot and in shoes. The groups were: Habitually shod adults in the USA, Recently shod adults in Kenya, Habitually barefoot adults in the USA, Barefoot adolescents in Kenya, and Shod adolescents in Kenya.
Each group ran in shoes and barefoot and they measured foot-strike pattern (whether the runner lands on the heel, midfoot or forefoot) and kinematic and kinetic variables like impact force, loading rate, and joint angles.
The findings - a shift in landing, a reduction in force
It turns out that people who run barefoot, even when shifting from shoes to the barefoot condition (the habitually shod groups), shift the landing point to the forefoot. There's nothing new there - it's been known for many years that running barefoot changes the footstrike. Hundreds of studies exist to show this. The next difference is the ankle angle - the barefoot runner has a more plantarflexed ankle when they land - what this means is that the toe is pointed away from the body more (compared to dorsiflexion, when you pull it back towards you at the ankle). Again, hundreds of studies have shown this.
Next are the impact forces. Here's where there is some disagreement. Previous studies have occasionally disagreed on how barefoot running affects impact forces - some say it actually increases them, with high variability between individuals. Most suggest a reduction, particularly early on during impact (first impact). The Nature study has found that being barefoot AND landing on the forefoot reduces both the loading rate and the peak impact force. In fact, it's three times lower in barefoot runners who forefoot strike (which is most of them) than in heel strikers wearing shoes. In theory (though this too is disputed), higher impact forces and loading rates equals greater injury risk, and so the study is suggesting that perhaps people who are barefoot or minimally shod have a better chance of avoiding injury.
A stimulus plan for physical therapists and podiatrists?
And here is where it gets tricky. I must point out that the title of the paper is Foot strike patterns and collision forces in habitually barefoot versus shod runners. I highlight the word "habitually", because it's quite important to appreciate the impact that this word may have on how you apply this finding.
I guarantee that the media are going to be all over this and they are going to tell you that you should be running barefoot or in Vibrams. You will hear how science has proven that being barefoot will prevent injuries, and that those of you who are injured should blame your shoes as you lob them into the garbage bin.
None of these suggestions is true, yet. And Dan Lieberman who headed up this latest study would not even be suggesting this himself. The final sentence in the paper in fact reads "controlled prospective studies are needed to test the hypothesis that individuals who do not predominantly RFS either barefoot or in minimal footwear, as the foot apparently evolved to do, have reduced injury rates" (good science always recognizes what it DOESN'T say, and Lieberman and co fit this category).
What the Nature study hasn't measured is the long term (or even the short term) effects of the change on loading rates on different joints. If you wish to guarantee yourself an injury, then go out for a 2km run barefoot on a hard surface, and you will be asking your calf muscles and Achilles tendons to do work that for perhaps 30 years, they haven't had to do.
And I will illustrate this with our own insight into footstrike and injury. When the Pose research was done in Cape Town, athletes basically had their footstrike patterns changed through 2 weeks of training in the new method. The biomechanical analysis found lower impact forces (sound familiar? Same as the Nature paper), and even less work on the knee joint. This was hailed as a breakthrough against running injuries, because lower impact plus lower work on the knee meant less chance of injury. Jump ahead 2 weeks, and 19 out of 20 runners had broken down injured. Why? Because their calves and ankles were murdered by the sudden change. And the science showed this - the work on the ANKLE was significantly INCREASED during the forefoot landing.
The point is, changing how you run, whether by technique training or a change in shoes (like running barefoot) will load muscles that may be very weak, and joints and tendons well beyond their means. If however, you are a habitually barefoot runner, then you can do this, because your body has been prepared for it. For everyone else, I think we may be underestimating the time it will take to transition successfully to barefoot running (or forefoot striking, if you're going to force that change 'unnaturally').
And there is my point - taking this kind of interesting study, and dispensing advice, is a risky business. As a friend pointed out yesterday - the media's interpretation of this study will be a "stimulus plan for physical therapists and podiatrists". Going from years of shoes into minimal shoes or barefoot will injure you if you are not careful.
The Nature study provides a good discussion point. It's intriguing, and certainly does suggest advantages to barefoot running. It is not the last word, but rather the latest word in this debate. Nor is it revolutionary, because for many years, we've known that being barefoot changes ankle angle on impact, footstrike and loading rates (though quite how they change is not agreed upon).
I'm sure a lot more will be written - I'll even cover some of it when I do that interview series on this topic in the coming weeks. For now, that's the last I'll say on this particular issue, but debate is always welcome!
P.S. Daniel Lieberman has launched a website on this topic, and it's well worth a look. It is obviously based on his research (this study forms the bulk of it), but it's a good, clear explanation of the concepts. Again, the same word of caution applies - don't jump from one to the other. If there is one section of that website that you should read over and over, it is the Training tips section. Most will not, and they'll become the statistics (and the stimulus for physical therapy), but if you manage it right, then the site will be a great help to you!
Start running and watch your brain grow
January 24th, 2010
The health benefits of a regular run have long been known, but scientists have never understood the curious ability of exercise to boost brain power.
Now researchers think they have the answer. Neuroscientists at Cambridge University have shown that running
stimulates the brain to grow fresh grey matter and it has a big impact on mental ability.
The television newsreader Emily Maitlis out jogging after taking her children to school. Research on mice shows that running and other aerobic exercise stimulate the growth of new brain cells, leading to enhanced memory recall. Photograph: Beretta/Sims/Rex Features
A few days of running led to the growth of hundreds of thousands of new brain cells that improved the ability to recall memories without confusing them, a skill that is crucial for learning and other cognitive tasks, researchers said.
The new brain cells appeared in a region that is linked to the formation and recollection of memories. The work reveals why jogging and other aerobic exercise can improve memory and learning, and potentially slow down the deterioration of mental ability that happens with old age.
"We know exercise can be good for healthy brain function, but this work provides us with a mechanism for the effect," said Timothy Bussey, a behavioural neuroscientist at Cambridge and a senior author on the study. The research builds on a growing body of work that suggests exercise plays a vital role in keeping the brain healthy by encouraging the growth of fresh brain cells.
Previous studies have shown that "neurogenesis" is limited in people with depression, but that their symptoms can improve if they exercise regularly. Some antidepressant drugs work by encouraging the growth of new brain cells.
Scientists are unsure why exercise triggers the growth of grey matter, but it may be linked to increased blood flow or higher levels of hormones that are released while exercising. Exercise might also reduce stress, which inhibits new brain cells through a hormone called cortisol.
The Cambridge researchers joined forces with colleagues at the US National Institute on Ageing in Maryland to investigate the effect of running.
They studied two groups of mice, one of which had unlimited access to a running wheel throughout. The other mice formed a control group. In a brief training session, the mice were put in front of a computer screen that displayed two identical squares side by side. If they nudged the one on the left with their nose they received a sugar pellet reward. If they nudged the one on the right, they got nothing.
After training the mice went on to do the memory test. The more they nudged the correct square, the better they scored. At the start of the test, the squares were 30cm apart, but got closer and closer together until they were almost touching. This part of the experiment was designed to test how good the mice were at separating two very similar memories. The human equivalent could be remembering what a person had for dinner yesterday and the day before, or where they parked on different trips to the supermarket.
The running mice clocked up an average of 15 miles (24km) a day. Their scores in the memory test were nearly twice as high as those of the control group. The greatest improvement was seen in the later stages of the experiment, when the two squares were so close they nearly touched, according to a report in the Proceedings of the National Academy of Sciences.
"At this stage of the experiment, the two memories the mice are forming of the squares are very similar. It is when they have to distinguish between the two that these new brain cells really make a difference," Bussey said.
The sedentary mice got steadily worse at the test because their memories became too similar to separate.
The scientists also tried to wrongfoot the mice by switching the square that produced a food reward. The running mice were quicker to catch on when scientists changed them around.
Brain tissue taken from the rodents showed that the running mice had grown fresh grey matter during the experiment. Tissue samples from the dentate gyrus part of the brain revealed on average 6,000 new brain cells in every cubic millimetre. The dentate gyrus is part of the hippocampus, one of the few regions of the adult brain that can grow fresh brain cells.
Ian Sample, science correspondent ; guardian.co.uk, Monday 18 January 2010
Source: The Guardian: http://www.guardian.co.uk/science/2010/jan/18/running-brain-memory-cell-growth
January 17th, 2010
Whether they began running to get into shape, to fulfill a lifelong dream or simply to have a good time, most runners share this belief: nothing feels better than crossing the finish line. Here are the stories of both elite competitors and determined beginners.
From the nun on the run to celebrities to the "everyperson"...
CCRR 2010 Clinic has started!
January 5th, 2010
The New Year has started off successfully with 29 intrepid runners joining the marathon and half marathon training clinic. We have a mix of female and male, older and younger, experienced and inexperienced runners, and all are keen!
All CCRR members are invited to join the clinic runs. Beyond the usually scheduled runs, Monday night is "Hill Night" until the end of February! Lead by Allyson MacDonald, runners will head for the "Hills of Albert" after a suitable warm-up run through downtown. Last night we ran four hills... and all survived!
January 2nd, 2010
You have set your goals, and today you have met the first goal: arriving at the gym at about 8:20 and meeting your fellow runners. I was happy to see you all, meet up with some old "runners" and quite a few new ones. My hat goes off to Jim, Gabriela, Tom and Gary for getting this course going.
For safety, injury and direction, the CCRR will always have leaders running at the back of the different groups. Do not feel guilty about your pace if you are one or two of those persons being followed. Over the years I have run with many slower runners and it is a pleasure for me to see them when they participate in their first 1/2 or full marathon. So don't be offended when your leaders are running with you -- they want to be part of your experience!
Oh, Oh Cathcart is making me rhyme
But I tell him he is running out of time
He'd better be running, running
Because Harry is coming, coming!
--From "The Back of the Pack" Harry
January 2, starting weight: 200 lbs
Distance: 8 kms
New Shoes: 0
Soon it will be Marathon Day
January 1st, 2010
John he yells, John he yells
It's running time in the city
ding-a-ling, hear Harry whine
Soon it will be Marathon time
slippy sidewalks, icy sidewalks
be sure you don't go down
In the air
There's a feeling of Winter.
leading mile after mile
And on ev'ry street corner you'll hear:
Cathcart's faster! Drost is slower
carry... ing a lot more weight
Ding-a-ling, hear them chime
John'll beat Harry one more time.
ps it the best I can do at such short notice. Happy New Year!