The Inaugural Asheville Marathon at the Biltmore - in Luna Sandals (Venado/original)

The Inaugural Asheville Marathon at the Biltmore - in Luna Sandals (Venado/original)

You're out on a run. Your nose is getting stuffy, so you lean to the side for a quick farmer's blow. It's cold out, but you didn't realize how cold until you go to wipe your nose with the back of your glove to clear off any additional moisture -- only to find that it's already frozen around the edge of your nostril in mere seconds.

Welcome to the inaugural Asheville Marathon, held on the grounds of the beautiful Biltmore estate. "Well," I thought dramatically at around mile 20, "At least I'll die somewhere majestic."

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Latest Vibram Five Fingers Reviews 1/27/10

This week's latest VFF reviews:

  • Vibram Five Fingers (VFF) KSO Trek at Rundurance [KSO Trek]

    So this is a review of the KSO Trek’s, which are very similar to my classic VFF KSO’s, except with new and hugely improved traction on the sole. The original KSO’s were very smooth, and so any sharp turns on a wet road or wet trail tended to get very slippery. I even found myself slowing down on tight turns out of fear for sliding off the trail (which did happen more than once). With the new Trek’s, that problem is solved completely. I have run on wet roads, wet trails, and packed snow without problems.

You can find last week's latest Vibram Five Fingers reviews here.

Vibram Five Fingers Trek Sport in Fall 2010 [New Product]

Above to the left is an upcoming Fall 2010 FiveFingers model called the FiveFingers Sport Trek displayed at the recent Outdoor Retailer event in Utah.  The Sport Trek simultaneously combines elements from the KSO, the KSO Trek, and the Bikila.
Above to the left is an upcoming Fall 2010 FiveFingers model called the FiveFingers Sport Trek displayed at the recent Outdoor Retailer event in Utah. The Sport Trek simultaneously combines elements from the KSO, the KSO Trek, and the Bikila. Beneath it in blue and grey is another color combination of the Bikila (previously unseen).
Alert! - 7/30/10 The all new Black Trek Sport has arrived at CitySports along with a new blue Bikila.

Last week and weekend was the winter market 2010 Outdoor Retailer trade show out in Utah. Vibram apparently had a booth and thanks to Bryon over at iRunFar, we get his scoop — seems Vibram is working on a FiveFingers Trek Sport for fall 2010 (now available here!). The VFF Trek Sport borrows elements from the KSO Trek, the KSO, and the Bikila — it has the Trek's sole; the KSOs synthetic upper (I assume a major selling point in the Vegan community); and the TPU toe protection, reflective bits, and an "achilles notch" similar to what we're seeing with the FiveFingers Bikila. Here's how Bryon put it:

The Vibram FiveFingers Trek Sport will combine the more aggressive outsole of the KSO Trek with and light upper similar to the KSO. While the upper will be light, Vibram has added a bit of TPU on the top of each toe as is found on the forthcoming Bikila model we discussed after last summer’s OR show. The FiveFingers Trek Sport will also feature reflective detailing, an achilles notch to make it more run-worthy, and a removable heel strap.

Re-read that last part — "removable heel strap." Many VFFers with KSOs have run into breaking heel-straps, a consequence of the "sawing" that can occur where the nylon strap bends on either side of the instep. A common way to fix this problem (mod) has been to tape up the KSO straps — as demonstrated by Jason.

The FiveFingers Sport Trek is expected to retail at $100.

Additionally, we are glimpsing a blue/gray combo of the FiveFingers Bikila. I have no idea if this color combo will be available when the Bikila comes out in the next couple months or later. Time will tell. Get it now!

So another year and another version of VFFs to ponder. It's becoming increasingly complicated for VFF fans to determine which Five Fingers will best suit their needs.

I say if you're new to VFFs, keep it simple. Go KSO or Classic first. You'll have plenty of time to flesh out your line-up in time. Or just try and get them all like Shawn!

What say ye, fans?

Again, thanks to Bryon for allowing me to share this on BirthdayShoes!

Erik takes his KSO Five Fingers to the Playground

It's a lot easier to do a bit of 'beam' walking in VFFs.
It's a lot easier to do a bit of 'beam' walking in VFFs.
FiveFingers are so amazing that you can levitate in them!
FiveFingers are so amazing that you can levitate in them!
Gotta say: if I was a little kid on a playground looking up at Erik here, I'd be a little scared!  Stranger danger!
Gotta say: if I was a little kid on a playground looking up at Erik here, I'd be a little scared! Stranger danger! Just kidding.
Top of the playground for Erik!
Top of the playground for Erik!
See what I'm saying about levitation?  Erik is flying!  Note the look on the face of his daughter!
See what I'm saying about levitation? Erik is flying! Note the look on the face of his daughter! Superdad!

Above is Erik, having an extraordinarily fun time on the playground in his black Five Finger KSOs. Here's what Erik had to say:

Justin,

I really enjoy your website and forum, as I've used it from the sizing guide (prior to getting my vffs) and ever since I've received them I've been checking in to see what's new. I figured I'd send some pics because I am enjoying my Vibram KSO's to the point where the use of conventional shoes (at work) has become a chore.

My wife took these pictures at the park near our house in Virginia Beach on an unseasonably warm day last weekend. Since I've gotten my VFF KSO's a month ago, I havent had many chances to use them outside the gym. We took our daughters to play, but I probably had more fun.

Thanks again,
Erik

It's a common saying that VFFs make you feel like a kid again — way to prove the point!

Digging into Daniel Lieberman's Barefoot Running Research

A Kenyan elite runner who grew up running barefoot but now runs shod is taped in slow motion running in running shoes.  Screencap from Lieberman research into barefoot running.
A Kenyan elite runner who grew up running barefoot but now runs shod is taped in slow motion running in running shoes. Screencap from Lieberman research into barefoot running.

Updated with poll results below!

As I try to keep up with all the buzz on the release of Daniel Lieberman's much-anticipated barefoot running research, I'm spending more time on Lieberman's Harvard old-school-styled website titled Running Barefoot or in Minimal Footwear, which for sake of reference, I'll refer to as "Running BoMF."

One of the things I noticed on Running BoMF that I'd like to dig into is Lieberman's speculation as to why approximately 75% of shod runners heel strike. Per Running BoMF's section Foot Strikes & Running Shoes:

  1. It's comfortable. The shock-absorbing features cushion the force of impact. The graph below compares the forces that occur at the ground for a runner landing on the heel when barefoot (a) and in a running shoe (b). Note the initial impact transient, a nearly instantaneous and large increase in force that occurs as the heel comes to a sudden stop upon impacting the ground. The shoe reduces the force by about 10% and slows the rate of loading considerably. This, in addition to distributing the impact force over a larger area of the rearfoot, makes it comfortable to heel strike.
  2. Thicker rearfoot cushioning than forefoot cushioning. This high heel makes it easier to heel strike because the sole below the heel is typically about twice as thick as the sole below the forefoot. So if your foot would tend to land flat when barefoot, it will land on the heel when in a shoe.


    Barefoot Heel Strike Ground Reaction Force

    Shod Heel Strike Ground Reaction Force

  3. It's stable. The shoe is designed to prevent too much movement such as pronation. This helps to make runners feel stable in modern shoes.

The thing that jumps off the page to me here is #2, "[If] your foot would tend to land flat when barefoot, it will land on the heel when in a shoe."

As I've moved away from both shod-running and shod-walking, I've observed substantial changes in how I strike the ground: in both instances, I've shifted towards using a forefoot strike. Striking with the forefoot has become secondhand now.

However, when I have to don shoes with a heel — and it doesn't take much heel to cause this — I find myself inescapably heel-striking. What gives? Well, my conclusion is the same as Lieberman's speculation: it's the elevated heels catching the ground when my foot reaches a near-flat clearance point.

Not that Lieberman was specifying any chronology here, but anyone who has ever watched young children or toddlers walk will tell you they walk on their forefoot — even in shoes (Granted, many of their shoes are moccasins without elevated heels like these). I contend that in a natural state, human beings would naturally learn to walk with a mid-foot or forefoot strike—just like little kids.

It's just that most shoes make a natural gait impossible*

Given that thicker heeled shoes can force a heel-strike, Lieberman's other speculations as to why shod runners heel strike naturally follow.

For one, given a cushioned heel that is getting in the way of a forefoot strike, you either fight the design of your shoe, requiring a sharper angle of approach at the forefoot so as to give the heel enough clearance to miss, or you just let the catch do it's thing and do your best to stay comfortable. I further speculat that even if you can manage a forefoot strike in a thick-heeled shoe, you're still going to lose some of the biomechanical efficiency that you get with a flat-shoe or barefoot because your foot won't be able to compress as far to the earth before ramming into the cushion of the shoe (And maybe this is why so many shoes try to capture that reduced compressibility via springs in the heels).

As for the third reason, this seems a natural extension given conditions #2 and #1: running shoes are designed to control your landing. With a monster spike in impact you get when running with a heel-strike, controlling that shock wave would be an important component in design as it's reverberation up your leg and foot could cause instability.

Anyway, I'm curious if anyone else has noticed that they forefoot strike while running or walking in VFFs or barefoot, but inadvertantly heel-strike in less minimalist footwear, and in particular as with shoes with elevated heels.

It's gotta be the shoes.
Update with poll results:

Below are the results of a poll that ran from January 28 through February 5 of approximately 100 minimalist footwear wearers. The results provide striking, albeit anecdotal, evidence that shoes with thick heels seem to force a heel-strike.

If you walk/run with a forefoot strike (barefoot or in VFFs), have you noticed that when wearing thick-heeled shoes they catch the ground, effectively forcing a heel-strike?

  • Yes: 94% (95)
  • No: 5% (5)
  • N/A. I don't forefoot strike.: 1% (1)


Total Votes : 101

Additional notes:

These two videos (barefoot and shod) showing an elite Kenyan runner in slow motion running in running shoes and then barefoot are used to illustrate how the angle of approach is the same in both instances, but in the shod-running video, the heel catches the earth, forcing a heel-strike. Lieberman uses this as an example to bolster his why-heel-strike-when-shod speculation on this page of his website.

Also, see Peter's video analysis of how individuals run shod or in VFFs here. I made similar comments on that post.

* Link is to a nine page read on the subject — I may go into more detail on this article at a later date as it is fascinating to me!

Results of Daniel Lieberman Barefoot Running Research

Results of Daniel Lieberman Barefoot Running Research
Screencaps from the Nature video, this image shows that initial impact running with a heel-strike registers at around 1.81 x body weight compared to .34 x body weight initial impact running with a forefoot strike. Interestingly, peak bodyweight impact on each curve registers higher with a forefoot strike — around 2.60 x bodyweight running with a forefoot strike compared to 2.30 x body weight with a heel-strike. Note in both running styles here, impact is measured with barefeet.

Daniel Lieberman, Professor of Human Evolutionary Biology at Harvard University, has been conducting a great deal of research into barefoot running. That research has been under peer review for some time now, but is (finally) beginning to see the light of day. What's the verdict? Here's one takeaway: Barefoot running requires a forefoot strike which brings down the impact force to 60% of one's bodyweight.

Before I get ahead of myself, let me kick this off with some video goodness discussing Lieberman's study courtesy of Nature:

There is a lot of press surfacing about Lieberman's research, and I am tracking all of those articles here (see links below). Also, you must take a look at the barefoot running website Lieberman has set up. It covers a great deal of information, from background research, differences between heel strike and forefoot strike running (similar to the graphic above), and even has tips on getting started running barefoot or in minimalist footwear. Check it out.

Now, as for some of the hullabaloo surrounding the research of this ground-breaking research, check out this quote from Nature's initial write-up, A Softer Ride for Barefoot Runners:

Lieberman found that long-distance runners who usually wear shoes, in both the United States and in Kenya, tend to land directly on their heels, abruptly bearing the full force of the impact. The force of the collision, even with a cushioned sole, was the equivalent to up to three times their bodyweight. The force could be linked to common running injuries such as stress fractures and plantar fasciitis, although this has yet to be demonstrated.

Americans and Kenyans accustomed to running barefoot, however, tend to strike the ground with the ball of their feet before touching down the heel — a fore-foot strike — allowing the tendons and muscles in the foot and lower leg to act as shock absorbers, bringing the impact force down to 60% of their bodyweight. The team's research is published in Nature.

"The ankle is a very compliant, springy joint, and barefoot runners use it a lot," says Lieberman. "It isn't available to you when you rear-foot strike. Then you're relying solely on the spring on the heel of the shoe."

The research conducted by Lieberman and also Madhusudhan Venkadesan and Dennis Bramble is described further in a separate Associated Press write-up, Barefoot runners ease into low-impact landings Study shows how humans ran comfortably and safely before the invention of shoes:

Working with populations of runners in the United States and Kenya, Lieberman and his colleagues at Harvard, the University of Glasgow, and Moi University looked at the running gaits of three groups: those who had always run barefoot, those who had always worn shoes, and those who had converted to barefoot running from shod running. The researchers found a striking pattern.

Most shod runners -- more than 75 percent of Americans -- heel-strike, experiencing a very large and sudden collision force about 1,000 times per mile run. People who run barefoot, however, tend to land with a springy step towards the middle or front of the foot.

"Heel-striking is painful when barefoot or in minimal shoes because it causes a large collisional force each time a foot lands on the ground," says co-author Madhusudhan Venkadesan, a postdoctoral researcher in applied mathematics and human evolutionary biology at Harvard. "Barefoot runners point their toes more at landing, avoiding this collision by decreasing the effective mass of the foot that comes to a sudden stop when you land, and by having a more compliant, or springy, leg."

Though none of this may come as a surprise to readers of Birthday Shoes, the importance of Lieberman's work here is that it further calls into question the prevailing paradigm that you must wear heavily cushioned shoes in order to run safely and injury free. Though there are no studies proving that barefoot running results in fewer injuries than shod-running, I have little trouble jumping from "reduced impact from barefoot running" and "how we evolved to run" to "running barefoot is a safer and more injury-free way to run."

It will be fascinating to learn more about Lieberman's research as it emerges from the ivory tower. If I recall correctly, Lieberman's studies also looked at Vibram FiveFingers-shod runners, so it will be informative to see what we learn there, as well.

Below are additional links or material covering the Lieberman barefoot running research release. Sit back, click around, and geek out on barefoot running:

Links to press on the Lieberman Barefoot Running research release:

Here's an NPR's All Things Considered on the study:

H/T to Tuck!