The Daily Bounce

Rule one, obey stoplight; Rule two, wear helmet

Published on May 25, 2010 in Cycling and Uncategorized. 0 Comments Tags: Cycling.

I was driving home mid-morning on a sunny Saturday. Stopped at a light, I noticed a slick bike descending the hill coming toward me. I was admiring the bike and –WHAM– next thing I knew the bike was in the air after hitting a car.

Twice in the last month there have been bike accidents in my town. The first was the accident I witnessed. The rider had a helmet on and walked away. The second rider did not have a helmet and died.

There are lessons in these two unrelated incidents. While it’s easy for cyclists to blame accidents on automobiles, and in the aftermath of a car/bike accident sympathy naturally flows to the fragile cyclist rather than the steel encased motorist, there are several things cyclists can do to improve their own safety. Both these accidents were caused by cyclists running a red light and the death in the second came from the lack of a helmet.

In the first accident, I saw the cyclist approaching bent out over his aerobars. He was wearing the kit of a local bike store and riding a time trial/triathlon bike. Obviously an experienced rider, he was stretching to make it through the intersection before the light turned red. (He missed that. I was already at a complete stop on the far side when I noticed him approaching). Ninety-nine times out of a hundred he would have sailed through the intersection on the red with no problem. This time, despite frantic braking, he “T-boned” into the side of a car in the intersection.

Fortunately, after the impact, he jumped up and walked clear of the road. He lamented, “I tried to stop.” Having a good helmet strapped on tightly undoubtedly played a large part in this happy end to a bad situation.

The second accident three weeks later was weirdly similar. A witness to that accident said “the light turned green and I saw the bike coming down and he smashed right into the car.” Again, it was a biker coming down a main road trying to pass through an intersection at the end of a green light, thinking that they could get through before any cars would enter.

Both accidents involved bikers hitting the side of cars after the light had changed.

Unfortunately, the second biker was just commuting around town and had no helmet. He too stood up in the roadway after his accident. But, he crumpled to the ground shortly after and passed away at the scene.

It’s easy to blame cars that don’t “see” cyclists (Tom Vanderbilt’s book Traffic talks about the psychology of driver’s perception and why motorists have a hard time seeing bikes and motorcycles). But, we cyclists need to take our own share of responsibility. It’s dangerous to sprint through a light about to turn red. And it’s foolhardy to ride without a helmet.

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The barefoot chase continues

Published on March 9, 2010 in Exercise and Running. 0 Comments Tags: Barefoot, Evolution, Running.

Mark Connell wired up at the Skeletal Biology Lab at Harvard

Ready to run on the treadmill

I got a call last week inviting me back to the Skeletal Biology lab as a test subject for their newest research project. The photo at the right shows me on the tread mill, after one of the data gathering sessions, with reflective, silver motion capture balls taped to my leg. Dan Lieberman and his lab are asking interesting questions and learning fundamental things about the mechanics of human motion. Strange as it may seem, no one before has looked in detail at what happens when your feet strike the ground.

If you haven’t seen it yet, do check out their web site, Running Barefoot, where the folks at the Leiberman lab discuss the “biomechanics of foot strikes
and applications to running barefoot or in minimal footwear”. As the subtitle makes clear, the title is a bit of a misnomer. The research and web site address foot strikes and how heel striking differs from forefoot striking, regardless of whether you’re wearing shoes. Shoes are useful tools, as anyone who runs in Boston winters can attest.

We talked about my impressions from participating in the previous study and it dawned on me that perhaps I wasn’t heel striking after all. While the heel of the shoe was contacting the ground before the front of my foot, my foot could well have been flexed downward, positioned to strike on the forefoot. The mechanics of this would be similar to that shown in the bottom pictures on this page (note how the bones align in the ankle and foot on the elite Kenyan runner) or in this video.

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Not running heel to toe

Published on January 29, 2010 in Running. 1 Comment Tags: Barefoot.

Mark Connell -- Lieberman barefoot running gait study in Nature

All wired up and nowhere to go

Much attention is focused on the new study by Daniel Lieberman just published in Nature which compares barefoot running to running in shoes.

More on the study below. But first, I’d like to share my counterintuitive experience as a test subject in the research that lead to this paper. To the left you can see a photo of me wired up and ready to run on the treadmill in the Skeletal Biology Lab at Harvard. How did I get there and what did I learn?

I volunteered. While not fully barefoot, I’ve been running using POSE technique at CrossFit for nearly three years now. (For the uninitiated, POSE approximates a barefoot gait by stressing a shortened, quickened stride; pulling of the feet off the ground rather than pushing and landing forefoot/midfoot underneath your center of mass). I use minimal shoes (Nike Free, which to true barefooters are still too squishy and have too large a heel).

Nevertheless, I made the cut. The study collected data with runners moving at a 9-, 8- and 7-minute per mile pace on the treadmill both barefoot and wearing running shoes.

In my first barefoot set it was easy to know that I was striking with my forefoot. The treadmill had a very hard surface because it had a pressure plate to measure the force of foot strikes. Any heel striking would have immediately produced pain.

When I moved onto my shod set (which utilized regular cushioned running shoes), I fully believed that my foot strike remained identical to what it was running barefoot. After all, I was “pulling not pushing” and consciously looking to land forefoot/midfoot.

I was sure that I was not running heel to toe. It wasn’t in my mental or prioperceptive image. After I finished, the technician replayed the video of my running. There I was barefoot with the ball of my foot hitting first and the heel gently flexing down before I pulled my foot off for the next stride. And … there I was with shoes on hitting first on my heel and rolling across to my toe. It wasn’t egregious. It was almost a flat footed strike with the middle of the foot being the impact point. But it wasn’t. In slow motion you could see that the first point of impact was my heel.

Intuition and reality can easily be different. This experience reinforced the wisdom of having a coach or other objective observer gauge what you’re doing to compare with what you think you’re doing.

===

Amby Burfoot over at Runner’s World has a great set of relevant links to other perspectives and an excellent executive summary provided by Daniel Lieberman, which speaks to what his paper doesn’t say:

Our paper shows ONLY how and why humans can and did run comfortably without modern running shoes. We confirmed what many people knew already, that most experienced, habitual barefoot runners tend to avoid landing on the heel and instead land with a forefoot or midfoot strike. The bulk of the paper explores the collisional mechanics of different kinds of strikes. We show that forefoot and some midfoot strikes (shod or unshod) do not generate sudden, large impact transients that occur when you rearfoot strike (shod or unshod). As a result, runners who forefoot or midfoot strike don’t need shoes with elevated cushioned heels to cope with these sudden, high transient forces. If impact transient forces contribute to some forms of injury (emphasis on IF and SOME), then this style of running (shod or unshod) might have some benefits, but that hypothesis needs to be tested. That’s it! We present no data and make no arguments about how people should run, whether shoes cause some injuries, whether barefoot running causes other kinds of injuries, and so on. There is a strong need for controlled, prospective studies on these problems.

Here are links to some prior Bounce articles on barefoot running, persistence hunting and the endurance running capabilities of humans:

The Evolution of Running: Why Do You Run?

Do short toes make humans better runners?

Running Barefoot: Like humans have for thousands of years

More Barefoot Running: Modern technology and human biology

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Can you run even faster–maybe

Published on January 28, 2010 in Rowing and Uncategorized. 0 Comments Tags: Running.

Usain Bolt -- Credit: friskytuna at http://www.flickr.com/photos/34128229@N06/

Usain Bolt winning the men's 2008 Olympic 100m

How about 40 mph? A newly published study from the Journal of Applied Physiology suggests that the theoretical limit to human speed might run that high.

“Where once the maximum top speed of a human being was thought to be around 28 mph, a new study suggests that a trained runner could achieve speeds of 40 mph, or perhaps even more.”

“The prevailing view that speed is limited by the force with which the limbs can strike the running surface is an eminently reasonable one,” said Weyand, associate professor of applied physiology and biomechanics at SMU in Dallas.

“If one considers that elite sprinters can apply peak forces of 800 to 1,000 pounds with a single limb during each sprinting step, it’s easy to believe that runners are probably operating at or near the force limits of their muscles and limbs,” he said. “However, our new data clearly show that this is not the case. Despite how large the running forces can be, we found that the limbs are capable of applying much greater ground forces than those present during top-speed forward running.”

In contrast to a force limit, what the researchers found was that the critical biological limit is imposed by time -– specifically, the very brief periods of time available to apply force to the ground while sprinting. In elite sprinters, foot-ground contact times are less than one-tenth of one second, and peak ground forces occur within less than one-twentieth of one second of the first instant of foot-ground contact.

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Tranquililty through fish oil

Published on January 2, 2010 in Nutrition. 0 Comments Tags: Omega-3.

While not directly capable of giving you zen tranquility, the omega-3 essential fatty acids commonly found in fatty fish and algae seem to play an essential role in neural processing that helps animals avoid sensory overload.

In a new study published in the journal Behavioral Neuroscience mice were challenged by startling them with loud noises. Those fed a diet high in the two omega-3 fatty acids – docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) – showed a markedly calmer reaction. The researchers attribute this to improved nervous system processing in those mice fed a diet high in omega-3 fatty acids and speculate this may be due to improved maintenance of nerve-cell membranes.

The body cannot make these essential nutrients from scratch. It gets them by metabolizing their precursor, α-linolenic acid (LNA), or from foods or dietary supplements with DHA and EPA in a readily usable form. “Humans can convert less than one percent of the precursor into DHA, making DHA an essential nutrient in the human diet,” added Irina Fedorova, PhD, one of the paper’s co-authors. EPA is already known for its anti-inflammatory and cardiovascular effects, but DHA makes up more than 90 percent of the omega-3s in the brain (which has no EPA), retina and nervous system in general.

In the study, the researchers fed four different diets with no or varying types and amounts of omega-3s to four groups of pregnant mice and then their offspring. They measured how the offspring, once grown, responded to a classic test of nervous-system function in which healthy animals are exposed to a sudden loud noise. Normally, animals flinch. However, when they hear a softer tone in advance, they flinch much less. It appears that normal nervous systems use that gentle warning to prepare instinctively for future stimuli, an adaptive process called sensorimotor gating.

Only the mice raised on DHA and EPA, but not their precursor of LNA, showed normal, adaptive sensorimotor gating by responding in a significantly calmer way to the loud noises that followed soft tones. The mice in all other groups, when warned, were startled nearly as much by the loud sound. When DHA was deficient, the nervous system most obviously did not downshift. That resulted in an abnormal state that could leave animals perpetually startled and easily overwhelmed by sensory stimuli.

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Among the benefits of exercise … longer telomeres

Published on December 3, 2009 in Exercise and Uncategorized. 0 Comments Tags: Exercise, Nutrition.

A study published earlier this week provides evidence that “strenuous, long-term exercise may have anti-aging properties by virtue of its effect on chromosomes.” Specifically, exercise appears to benefit telomeres, which function as a protective cap at the end of chromosomes.

It has been known for a while that telomeres function like cellular clocks. With each division the telomere gets shorter and the cell gets older. Measuring the length of telomeres in a cell provides a good estimate of the age of that cell line.

This new study, involving about 100 subjects, showed that blood cells isolated from endurance athletes showed increased activity of telomerase, an enzyme which helps to repair the telomeres at the end of chromosomes.

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Nucleotides and the Paleo Diet

Published on August 15, 2009 in Nutrition. 0 Comments Tags: Immune system, Nutrition, Paleo Diet.

Fresh liver--a rich source of nucleotides

This article originally appeared in The Paleo Diet Update, v5, #33 – Nucleotides and the Paleo Diet (August 14, 2009), published by www.ThePaleoDiet.com and Loren Cordain, Ph.D. It was written by Mark Connell of nuBound and is reprinted with permission.

The Paleo Diet Update newsletter is a great nutrition resource. Subscribe to The Paleo Diet newsletter to begin building your own archive!

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NUCLEOTIDES AND THE PALEO DIET

Nucleotides are small molecules that are the building blocks of DNA and RNA. They are composed of a nitrogen-containing base bonded to a sugar and one or more phosphate groups. Nucleotides occur in all foods of animal or vegetable origin as free nucleotides or nucleic acids. Their concentration depends on cell density, which explains why organ meats are such a rich source.

Traditionally, nutritionists have dismissed any dietary need for nucleotides arguing that the body can produce them itself. This view has begun to change over the last two decades as a mounting body of research has demonstrated that dietary sources of nucleotides play several key roles.

One hint to the larger story is that the preponderance of foods with high concentrations of nucleotides are Paleo foodstuffs, such as game, organ meats (heart, liver, spleen, lungs and sweetbreads) and whole fish. /1-2 Human milk also contains high levels of nucleotides. /3

Research has uncovered multiple roles for dietary nucleotides, including growth and repair of the intestinal lining and liver, /4-5 modulation of the immune system, /6-7 and protein synthesis, /8 among other functions.

While the body is able to synthesize nucleotides from scratch, dietary sources of nucleotides are now considered semi-essential nutrients /9 under stressful conditions (which hamper the body’s synthesis of nucleotides), such as rapid growth, malnutrition or infection. Additionally, certain tissues, such as the gut, which have a low capacity to produce nucleotides on their own, utilize salvage of dietary nucleotides to meet much of their need.

The long recognized superior health of breast-fed babies /10 is now attributed in part to the presence of nucleotides in mother’s milk. /11 Several infant formula makers now add nucleotides to their cow’s milk-based infant formula in an attempt to more closely mimic nature.

The lining of the gut is subject to rapid turnover with complete replacement occurring in less than one week. /4 Nucleotides assist both the continuous proliferation of cells and promote the development of the folds (villi), which allow proper absorption of nutrients. /12 Maintaining the integrity of the gastrointestinal tract is key in avoiding the complications arising from leaky gut.

Immune suppression is well documented in both endurance and strength/power athletes. /13 Recent studies of athletes supplementing their diet with nucleotides have suggested an improvement in immune function and faster recovery. /14-15

The Paleo Diet offers an abundance of nucleotides in comparison to a Neolithic diet, which includes the newer grains, dairy, and sugar never eaten by our Paleolithic ancestors. Basing your meals on the Paleo Diet, mainly lean meat, seafood, fruits, and vegetables, can help with intestinal permeability, immune function, and other functions that dietary nucleotides have been found to enhance.

References:

1. Siegfried Souci, W. Fachmann and Heinrich Kraut. 2008. Food Composition and Nutrition Tables, 7th Edition. Medpharm.

2. Rodney Grahame, H. Anne Simmonds and Elizabeth Carey. 2003. Gout: Answers at Your Fingertips. London: Class Publishing Ltd.

3. Agget P, Leach JL, Rueda R and MacLean WC. Innovation in infant formula development: A reassessment of ribonucleotides in 2002. Nutrition. 2003; 19:375-384.

4. Carver JD. Dietary nucleotides: effects on the immune and gastrointestinal systems. Acta Paediatr Suppl. 1999; 430: 83-88.

5. Grimble GK. Dietary nucleotides and gut mucosal defense. Gut. 1994; 35: Suppl S46-S51.

6. Gil A. Modulation of the immune response mediated by dietary nucleotides. European Journal of Clinical Nutrition. 2002; 56:Suppl 3, S1-S4.

7. Maldonado J, Navarro J, Narbona J and Gil A. The influence of dietary nucleotides on humoral and cell immunity in the neonate and lactating infant. Early Human Development. 2001; 65 Suppl: S69-S74.

8. Sanchez-Pozo A and Gil A. Nucleotides as semiessential nutritional components. British Journal of Nutrition. 2002; 87:Suppl. 1 S135-S137.

9. Grimble GK. Why are dietary nucleotides essential nutrients? British Journal of Nutrition. 1996; 76:475-478.

10. Dewey KG, Fleming J, Nommsen-Rivers LA. Differences in morbidity between breast-fed and formula-fed infants. J Pediatr. 1995; 126:696-702.

11. Schaller JP, Kuchan MJ, Thomas DL, Cordle CT, et al. Effect of dietary ribonucleotides on infant immune status. Pediatric Research. 2004; 56:883-900.

12. Ortega MA, Nunez MC, Gil A and Sanchez-Pozo. Dietary nucleotides accelerate intestinal recovery after food deprivation in old rats. Journal of Nutrition. 1995; 125:2090-2095.

13. Nieman DC. Marathon training and immune function. Sports Medicine. 2007; 37(4-5): 412-415.

14. McNaughton L, Bentley DJ and Koeppel P. The effects of a nucleotide supplement on salivary IgA and cortisol after moderate endurance exercise. J Sports Med and Physical Fitness. 2006; 46:84-89.

15. McNaughton L, Bentley DJ and Koeppel P. The effects of a nucleotide supplement on the immune and metabolic response to short term, high intensity exercise performed in trained male subjects. J Sports Med and Physical Fitness. 2007; 47:112-118.

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A true warrior and a class act

Published on August 6, 2009 in Martial Arts. 0 Comments Tags: Brazilian Jiu Jitsu, Martial Arts.

Kenny Florian, top, and Mario Delgado spar in preparation for Florian’s UFC championship fight against BJ Penn. Gretchen Ertl for the Boston Herald

Dan Duggan at the Boston Herald has a great piece today on Kenny Florian as he prepares for his UFC title fight this weekend. He tracks Kenny’s evolution from a Boston College grad with a professional job into the top contender for the UFC lightweight title.

It’s not been a straight path. He’s seen three big defeats, but like a true jiu jitsu blackbelt he’s leveraged each of them into something better. He lost his first big MMA fight in 2004 to future-UFC regular Drew Fickett, but so impressed UFC President Dana White that he got a place on The Ultimate Fighter reality TV show. He made it to the finals of the show, but lost again, this time to Diego Sanchez. Once more, his pluck won him the offer for future fights in the UFC. A series of three wins got him a title shot in 2006 against Sean Sherk. After a five round battle, Kenny came up short for the third time in his career. Yet again he rebounded and after six straight wins has earned another title shot this Saturday night against jiu jitsu legend BJ Penn.

As Dan makes clear, Kenny has moved forward in his career by getting smarter, not meaner. After each defeat, he’s added new skills to his arsenal. And he’s done so by finding the best teachers, including Roberto Maia for jiu jitsu, Darryl Gholar and Alejo Morales for wrestling, and over the last five years Mark DellaGrotte for Muay Thai. He’s complemented his increasing mastery of skills with a dedication to conditioning and diet. Smart, skilled and dedicated, that’s a combination for success!

Kenny seems to be confident and relaxed with this combination. I’ve known Kenny for the last year or two (although I can’t claim to be more than an acquaintance). I happened to be in his neighborhood last week and stopped by the gym. Kenny saw me outside and waved me in to watch he and Mario Delgado rolling. No secrecy, no tension, no nerves. Just a couple of athletes passing pointers back and forth.

Reviewing strategies and discussing techniques they sounded more like a pair of high school wrestlers discussing an upcoming tournament, than the top ranked contender preparing for the fight of his career. As Kenny said afterward, training is like an airplane flight. He’s been at high altitude and now he’s got his feet back on the ground. He’s ready for the next step in his journey.

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Locomoting a dynamic warmup

Published on August 2, 2009 in CrossFit and Martial Arts. 0 Comments Tags: Brazilian Jiu Jitsu, Warm Up.

Ido Portal's Locomotion Conditioning

Robb Wolf linked to some of the capoeira-inspired floreio improvisation his friend Ido Portal is developing. It’s great stuff, but demands a high level of gymnastics skill (more than I currently possess or aspire to).

But, looking through Ido’s site I came across a set of basic locomotion drills he uses for warm up and conditioning. I’ve been wanting some different ways to mobilize prior to doing jiu jitsu and there’s a lot in here that’s useful. Some of these skills are familiar like the duck walk and the lizard walk, while others are new to me, like the horse and ostrich walks. Ido notes that the routine includes:

many different kinds of locomotion, in various challenging positions – on your hands, while squatting, crawling close to the ground, with locked knees, in a wide sumo-stance, etc…
Each movement provides a different and valuable component in the workout, from mobility to strength endurance, stabilization and more.

I’ve embedded the Beginner’s Version of these drills as a starting point, but do take a look at Ido’s piece and see the intermediate and advanced progressions. The dynamic stretching and warm up from these drills is a much better way to get going than static stretches.

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Improving from three percent efficiency

Published on July 30, 2009 in Swimming. 0 Comments Tags: Swimming.

The zen master of swim coaches, Terry Laughlin at Total Immersion, has just released a video of his presentation at the New England Multisport Expo.

After a lifetime of swimming just well enough to save myself from drowning, I decided a few years back to make an effort to improve. With a sense of trepidation, I committed to suffering through the necessary laps to accomplish this. But, before embarking on this painful course I came across Terry and his refreshing approach. His coaching philosophy, stressing efficiency gains over struggle, has revolutionized my relationship to the water and has made swimming one of my favorite activities.

Introducing this lecture, Terry notes:

The average human swimmer converts only 3% of energy and “horsepower” into forward motion. The other 97% gets diverted into our struggles with sinking, instability, drag, our inability to “grip” the water, etc. For comparison, elite swimmers are just 10% efficient — that’s right, even Michael Phelps wastes 90% — whereas dolphins are 80% energy efficient.

This means that the overwhelming opportunity for improving your endurance or speed is to reduce energy waste, not increase power or fitness — since 97% of what you add will go to waste anyway if you don’t address the waste.

In a series of six video clips, Terry covers:

1) Introduces his talk and makes the point that every session swimming should have the goal of improvement [embedded above];

2) Expands on the efficiency argument and explores the balance between propulsive and resistive forces acting on a swimmer;

3) Considers the difference between land (where performance comes from “building the engine”) and water (where “shaping the vessel” is the key).

4) Notes how mid-line stabilization enables you to gain propulsion through hip drive (gee — shades of CrossFit);

5) Emphasizes how the hand must extend the body line to split the water; and

6) Finally, Terry takes questions from the audience.

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The Daily Bounce

Rule one, obey stoplight; Rule two, wear helmet

The barefoot chase continues

Not running heel to toe

Can you run even faster–maybe

Tranquililty through fish oil

Among the benefits of exercise … longer telomeres

Nucleotides and the Paleo Diet

A true warrior and a class act

Locomoting a dynamic warmup

Improving from three percent efficiency

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