Sunday, April 28, 2013

Minimalist running shoes: Are they really what we want them to be?

Like many I began to think about so-called minimalist running after I read Christopher McDougall's Born to Run, which tells the story of the seemingly superhuman Tarahumara Indians and their ability to naturally run for miles (and essentially barefoot). Similar to what the Paleo diet has done in nutrition circles to reinvigorate an ancestral perspective with nutrition (to essentially think of nutrition or diet composition as something that should be strongly informed by what our ancestors ate thousands of years ago), McDougall's book sheds like on running from the perspective of human evolution.

Around the same time the book came out in 2011, discussions about barefoot running really started to take off and contributed to the serge of minimalist running shoes that came onto the market. (Many of the major running shoe brands now have at least one minimalist option.) A 2012 study in the Journal of Strength and Conditioning Research found that about 75% of more than 6,000 runners surveyed said they were "at least somewhat interested in running barefoot or in minimalist shoes."

So what's all the hype about? Why are so many people interested in minimalist running shoes?

More and more research is pointing to several benefits from barefoot running, such as fewer injuries or better performance. This study found runners in minimalist shoes or barefoot were 2-3 percent more economical while running on a treadmill than running in standard running shoes, likely due to improved "elastic energy storage and release in the lower extremity during minimal-shoe running." Comparing injury rates between runners wearing minimalist shoes (or running barefoot) and those wearing traditional shoes, other researchers found an injury rate 3.4 times higher in those wearing traditional shoes.

The basic argument for increased injuries when wearing traditional running shoes has everything to do with the biomechanical differences in foot strike. As I've discussed previously, when heel striking the equal and opposite force that is generated sends a shock to the ankle, knee and hips. Conversely, during a forefoot strike (which is more common with barefoot and minimalist runners), there is a much smaller impact force that's generated. For those interested in exploring this more, I highly recommend the above link on biomechanical differences in foot strikes. Looking back at the 2012 study of 6,000 runners I just mentioned, injury prevention was the most common reason for choosing to run barefoot or in minimalist shoes. More than a third of those running barefoot or in minimalist shoes said it was prevent future injury.

But, for some of the benefits, there are certainly some risks, particularly for those making the transition to minimalist/barefoot running after years or decades of running and walking in traditional shoes. In Lore of Running, Dr. Tim Noakes writes "only those with perfect biomechanical function were able to survive training; those with less than perfect function were soon injured and dropped the sport. Today, many runners who have very bad biomechanics are able to run prodigious distances only because of the very real improvement in the design of running shoes. In the past, they would simply have had to stop running because of recurring injury."

In fact, there has been research to suggest that many of the benefits of barefoot running are in those who have consistently trained their feet and surrounding musculature to adapt. The main take-away - if you're interested in running barefoot or in minimalist shoes, it's going to take time. More on this later.

I'm personally about a year into the process of transitioning to more minimalist running (for all the reasons I've already discussed).

I went from running in these about 18 months ago...
To these about 6-12 months ago...

And began running in these about 4 months ago...

But one of the interesting questions - and one that isn't addressed often in the literature - is if minimalist running shoes actually does a good job of simulating barefoot running from a biomechanical perspective. There's plenty of evidence showing a clear difference with traditional running shoes, but studies often lump minimalist running shoes into the same category as barefoot running. The big question this a good assumption?

Well, taking a look at a study from earlier this year published in the British Journal of Sports Medicine suggests it might not be. Researchers looked at the 3-D kinematics at the hip (top panels), knee (middle panels) and ankle (bottoms panels) joints for the stance phase of the gait cycle (this is when the foot is in contact with the ground) of four different shoe types: barefoot, minimalist, racing flat, and traditional running shoes.

Here is a breakdown of what they found...

It's slightly difficult to interpret because the graph is a little small, but here are two main points.

First, you'll notice that much of the kinematic variation is at the ankle and knee, and much less so at the hip. Barefoot runners showed a reduction in peak power generation at the knee, but an increase at the ankle compared to all other running types. You basically have a shift in the joint being stressed when barefoot running from the knee to ankle. This is, in my opinion, one of the important reasons for a gradual transition if you're thinking about dumping those regular running shoes and hitting the pavement barefoot.

As I mentioned before, it takes time to build the necessary foot and ankle strength to accommodate barefoot running (or minimalist shoes in some cases). By making the transition too quickly you run risk of injury. This is even the case when transitioning from traditional running shoes to more minimalist shoes. Start by spending more time walking around the house barefoot, or introduce one workout a week in more minimalist shoes. Over time and with increased strength in the foot, ankle, and calf, you'll be able to slowly build volume.

Second, kinematic analysis showed that the joints examined tended to act more alike in minimalist, racing flats, and regular shoes, compared with barefoot running, which had it's own unique kinematic profile. So, what does that mean? Well, essentially, there isn't too much of a difference between regular running shoes and minimalist shoes from a kinematic perspective, despite all the marketing claims. (One word of caution: this study looked only at one particular type of minimalist shoes - the Nike Frees - and didn't necessary look at all commercially available minimalist shoes, such as those from New Balance, Saucony or Brooks.)

So, if the hope is to mimic barefoot running by buying a pair of minimalist shoes, you might just want to slowly ease into the real thing. As much as we'd like minimalist running shoes to give us the same experience as running barefoot; well, that simply might not be the case. And if you're hoping to improve your biomechanics, you might get a higher bang for your buck by focusing on running technique and drills instead of dropping a hundred bucks on a new pair of kicks. Recalling the mantra of running coach James Dunne - form before footwear!

Wednesday, April 17, 2013

Comparing obesity trends in the U.S. with other countries

Last week PBS Newshour published an interesting article reporting on obesity trends among some of the major developed countries around the world, including the United States. Using an interesting resource by the Organization for Economic Co-operation and Development (an organization of 34 industrialized countries, including the U.S) called the Better Life Index, the tool below lets you explore and compare obesity trends across different OECD countries.

Thursday, April 11, 2013

Race Report: Cherry Blossom 10-miler

Last weekend I kicked off my 2013 season running the Cherry Blossom 10-miler. Though the cherry blossom's weren't exactly in peak bloom, I was excited to finally - after five years of living in Washington, DC - have the chance of running the city's most well-know spring race (I'd say the Marine Corps Marathon takes the cake for the fall, and easily wins out for total number of participants). Next to the Broad Street Run held in Philadelphia, though, which attracts over 30,000 runners, this race is one of the most well-know 10-milers out there. This year's race even hosted this year's U.S. Women's Ten Mile Championship.

Entering the race, I was certainly treating it more like a training run - a barameter test for my fitness at this point rather than the culmination or end point. In other words, it was a 'check-up' race and my expectations were to treat my performance as an opportunity to gather feedback on how I was progressing with my training.

As I've mentioned in previous posts, this year is really about speed, particularly holding speed off the bike. And getting faster is a lot of work and it takes time. I've also made a number of changes to my training and spent a fair bit of time over the winter focusing on things other than running, like swimming and cycling. During the course of trying to improve my cycling endurance and power, I've put on a couple extra pounds of muscle, particularly in my legs (maybe 3-4 pounds heavier overall compared with my weight heading into the Philly Marathon). This, combined with really only dedicating two days (for a few weeks it was three) per week for run training, I wasn't entirely sure how this all would play out. Having even small changes in weight in your legs or feet has a definite impact on running economy and biomechanics, and I knew I somewhat neglected my run this winter.

With my true focus on Olympic distance triathlon training this year and preparing for the Age Group National Championships later this year, my approach for Cherry Blossom was to gauge what my 10k time looked like (10 km is the distance of the run leg of an Olympic distance triathlon) and how it compared with my goal pace. Essentially, my goal was the hold a steady pace of six minute miles for as long as I could (ideally the entire race to give me a 1:00:00 finish time).

The first few miles my legs just felt heavy. I didn't know if it was the whole added weight thing in my legs or if I didn't warm up enough, but my quads were definitely burning. Regardless, I caught a glance of the race clock at the first mile marker - 5:58. I thought to myself, "Okay, good pace, let's try and settle in."But, for as much as I thought about it, my body sure didn't feel like it was following suit.

At the same time I was passing the next few mile markers at almost exactly six minute intervals, I couldn't shake the negative thought that I hadn't prepared enough and wouldn't be able to sustain the pace for the entire race. There was even a time around mile 4 or 5 when I though, "man, I can't keep this up."

A little after that thought, I came up on the next aid station and my only thought was, "I need a boost."

Now, my nutrition leading into the race was pretty much the same. Continued with my normal higher fat diet with plenty of vegetables, and slowly increased carbohydrate intake a few days prior to the race (nothing major but small substitutions here and there). I mainly did this because I knew I'd be running at fairly close to lactate threshold and would be burning primarily glycogen. Because I knew I was mostly burning sugar, I thought, "why not just use a little Gatorade."

I've had Gatorade or gels during races before, but last year I really shifted away from sugar-based race nutrition in favor of something called UCAN Superstarch, which is a much slower release starch that doesn't spike blood glucose levels nearly as much to enable the body to better tap into fat stores. I think there's definitely a placebo effect when it comes to sports drink or gels, particularly with races under 60 or 90 minutes, but at this point, I needed something. So, at the aid station I grabbed for a cup of Gatorade.

Not more than a mile later...a runner's worst nightmare...G.I. issues. Oh, great!

I'll be honest, I thought about stopping. But after a half mile or so, things finally worked themselves out and I was feeling pretty good. Even better, I felt like I was finally developing a bit of a rhythm - albeit a slightly slower one than I'd hoped. I passed the 10k mark and was only slightly slower than my goal pace for triathlon this year - not bad. Sure, I'm going to need to be able to swim 1.5 km and bike 40 km before I hold this same pace, but that's something for another day. I just wanted to finish this thing pretty close to what I ran Broad Street last year (1:01:25).

I was passed a few times on the back half of the race, which was a bit discouraging (something to work on, right?). Though, despite how much slower I thought I was going, I was still keeping a decent pace - about 6:10 or so. Coming out of Haines Point I knew the finish line wasn't too far away. Those last 800 meters seemed to take forever. I could finally see the finish chute, and I was totally focused on getting to the finish line (a little too focused maybe because I didn't see or hear my wife cheering for me at the end - sorry Steph).

I crossed the line at 1:01:45.

All things considered, I was pretty happy with it. Only twenty seconds off my time from last year and this was my first race of the season. I knew going into the race I didn't feel anywhere near my peak, but I still had a decent showing - 177th overall out of 17,530 finishers and 47th in my age group.

Most importantly, though, I came away from the race learning a couple valuable things that will really help me tweek things going forward to ultimately get better. And that's what this race was all about.

Thursday, April 4, 2013

Monthly Reading Roundup: March 2013

This month I finished a very interesting book (and fairly quick read) about the commercialization of youth sports. From the perspective of someone who was in the thick of it throughout my adolescent years, it's certainly an eye opener. From gym classes marketed towards 6-month-olds, to the growing industry associated with college recruiting, the book certainly sheds light on some important child/adolescent development issues and poses some critical questions, which any parent might find helpful in contemplating.

A few interesting studies came out this month, one in particular dealing with low-fat milk consumption and whether it actually helps manage weight among adolescents. I also included a study from earlier this year about running in minimalist shoes and whether it actually simulates barefoot running, which they are often marketed as being able to do. (Stayed tuned for a future post on this topic)


The Most Expensive Game in Town: The rising cost of youth sports and the toll on today's families, by Mark Hyman


"Effects of promoting longer-term and exclusive breastfeeding on adiposity and insulin-like growth factor-I at age 11.5 years," Martin R.M., et. al (Journal of the American Medical Association, March 13, 2013)

"Running in a minimalist and lightweight shoe is not the same as running barefoot: a biomechanical study," Bonacci J, et. al (British Journal of Sports Medicine, January 2013)


"'Crunch time' poll: Parents don't recognize kids are overweight," LA Times, February 26, 2013

"Ruminations on Aspartame and Milk," Huffington Post, April 1, 2013

"Study finds viscous cycle between obesity and physical activity," PsychCentral, April 1, 2013


"All of the structure and functions of the human body are built from and run on nutrients. All of them." -- Janet Lang, B.A., D.C.