Saturday, March 31, 2012

Half Squat Is Not A Squat

I hate half squats…so fucking much. Every time you don’t squat to depth, I pour a beer down the drain. And I HATE wasting beer. I just don’t understand why people think it’s okay to do partial reps of anything, much less in squatting. Muscular development or strength is achieved by working muscles through a full range of motion. Squatting, benching, or curling through half of the ROM only trains the musculature through that given ROM and typically subjects it to injurious forces. For example, a half squat will not utilize the adductors, hamstrings, gluteals, or external rotators and as a result place excessive stress on the anterior aspect of the knee. This is why ignorant people claim that squats are bad for the knees. And wWhy would someone want half a muscle?

Ego lifting is such a joke. Aside from the “let’s see how many plates I can put on the bar”, it isn’t quantifiable whatsoever. There’s no way to determine if one rep is comparable to another. It drives me insane

Thursday, March 29, 2012

Exposure to Bacteria Boosts Immune System

by Shawn Radcliffe

Your germ-free lifestyle could be making you sick.

It’s time for the all-out war on bacteria to stop. Not all microbes cause diseases like smallpox or tuberculosis. In fact, exposure to bacteria early in our lives is an essential step in developing a healthy immune system, according to researchers

This concept—known as the hygiene hypothesis—is not new. A recent study reported in the journal Science, though, showed just what happens when you take cleanliness to the extreme.

Researchers examined two groups of mice, the first exposed to the millions of bacteria and other tiny organisms that normally inhabit our world, and the other raised in a germ-free space, like a sterile “bubble” for rodents.

Mice raised in the germ-free environment had weaker immune systems, along with increased inflammation in the lungs and colon, something that occurs in people with asthma or irritable bowel syndrome.

Being born in a sterile environment didn’t doom the mice to weakened immune systems forever, though. Exposing them to microbes typically seen in mice enabled their immune systems to ramp up to full strength. This only happened if they were inoculated during the first few weeks of their life. Older germ-free mice didn’t see the same benefits.

The researchers aren’t suggesting that you should give up on routine hygiene—such as hand washing and vaccinations. These steps are still important in protecting you from some of the more dangerous microbes.

Going overboard with hand sanitizers and cleaning products, however, may not be doing you any favors. In fact, running or biking in the mud might be just what the doctor ordered to keep your immune system primed and ready for its next fight

Wednesday, March 28, 2012

How Fast Can an “Average” Kid Run a Mile?


Try any activity that involves timing or measuring, and it doesn't take long before you start to wonder: How do I stack up? Am I above or below average? By how much? Well, I can't answer that question in a general sense, but I can offer a bit of data that is at least mildly entertaining. It's from a study by Australian researchers in the British Journal of Sports Medicine, who collected data from 16 studies (a total of 85,347 test performances) to put together a comprehensive look at how kids between the ages of 9 and 17 perform on a series of physical tests. For example, here are the average, 10th percentile, and 90th percentile performances for the mile run (the vertical scale is in seconds, the horizontal scale goes from 9 to 17 years old):
More interested in how your muscles stack up? I was certainly glad to see that, despite the persistent mockery of my friends, I'm actually considerably stronger than most 12-year-old girls. I didn't post any of the data on flexibility, because that would be too depressing. So how does this compare with kids in North America? I don't know. Certainly, standards for the Presidential Fitness Test have been dropping in recent years. I didn't realize that you can now take the "President's Challenge Adult Fitness Test" (which includes a 1.5-mile run) on your own, enter your data online, and find out where you stack up relative to the general population. Has anyone tried this? Are the results surprising?

Tuesday, March 27, 2012

Pink Slime – What Are You Eating?

We’re not talking about the stuff from Ghostbusters II, we’re talking about the stuff you’re seeing all over the news lately that is said to be part of over 70% of the ground beef in U.S. supermarkets.

Pink Slime - Not with TX Bar Organics

What is Pink Slime?

The product recent news reports are to referring to as “pink slime” is actually a product the USDA calls boneless lean beef trimmings (BLBT). It is a beef byproduct made by separating lean beef from fat, which otherwise could not be done manually. It involves a separation process that sometimes involves the addition of a food grade ammonium hydroxide gas to destroy bacteria. The end result is lean finely textured beef that is blended into foods like ground beef – mainly used as a filler.

Monday, March 26, 2012

The five best home remedies for colds, coughs and the flu

Garlic tea immune enhancer
A well-known immune system strengthener, garlic shines as an antibacterial and antiviral herb for fighting colds, coughs and the flu. One of the best ways to take advantage of garlic's healing properties is by drinking fresh garlic tea. Sweetened with a little raw honey, it's delicious and helps to heal what ails you. Peel 2 to 3 cloves of fresh garlic and lightly crush them with the side of a wide knife blade. Add them to 2 cups of water and bring to a boil. Lower the heat and simmer for another 15 minutes. Strain the garlic and allow the tea to cool to mouth temperature. Add raw honey, a tiny pinch of cayenne pepper and a squeeze of lemon juice. Drink as much as desired.

Red onion and raw honey cough syrup
A wonderful home remedy for adults or kids suffering from a cough uses brown cane sugar, raw honey or stevia and red onions to make a soothing and tasty cough syrup. Wash, peel and slice the entire onion horizontally. Starting with the base of the onion, layer the slices in a bowl alternating with layers of raw honey or brown sugar. Stevia powder works well for this home remedy too; however, it is extremely sweet. Continue adding layers of onion and sweetener until the entire onion is reconstructed in the bowl. Cover and allow the sweetened onion to remain in the bowl on your counter for about 12-15 hours or overnight. The next day, there will be about a cup or more of sweet syrup in the bowl. The cough syrup contains a range of nutrients, vitamins and minerals from the onion and the honey to help fight infection and soothe sore throats and quiet a cough. Take a spoonful as needed. Has no onion-y taste.

Raw honey and lemon for sore throats
A mixture of fresh lemon juice and raw honey provides soothing relief for sore throats and helps stop the tickle that stimulates coughing. Raw honey -- with all its components including royal jelly, propolis and bee pollen -- is high in nutrients and enzymes which kill bacteria and viruses. The vitamin C and antioxidants found in fresh lemons boost the immune system, speeding healing. Together these two home remedies are a powerhouse for getting over a cold and sore throat. Mix the juice of 1/2 the lemon with 2 to 3 tablespoons of honey and sip throughout the day as needed.

Chicken soup antiviral
Chicken soup really does act to knock out a cold or the flu and hasten healing. As long ago as the 12th century, the Jewish physician Maimonides recommended consuming chicken soup to fight colds and flu. Take advantage of the high antioxidant properties and nutrients found in organic vegetables and chicken. Although non-organic chicken soup may relieve some cold symptoms, it also supplies the body with pesticides, growth hormones, herbicides and antibiotics that are not recommended for well being. Go organic all the way and get well quickly.

Mullein tea for coughs and congestion
Mullein tea is well-known for relieving chest congestion from coughs, colds and the flu. It acts as an expectorant, loosening trapped mucous and soothing sore throats. Make mullein tea by filling a tea ball or strainer with dried mullein herb and steeping in a cup of boiling water for 10 minutes. Sweeten with raw honey and drink as needed to relieve symptoms.

Saturday, March 24, 2012

Are there good viruses?

A fascinating article in Wired documents the search for a broad-based attack against viruses.

Virologists, in other words, are still waiting for their Penicillin Moment. But they might not have to wait forever. Buoyed by advances in molecular biology, a handful of researchers in labs around the US and Canada are homing in on strategies that could eliminate not just individual viruses but any virus, wiping out viral infections with the same wide-spectrum efficiency that penicillin and Cipro bring to the fight against bacteria. If these scientists succeed, future generations may struggle to imagine a time when we were at the mercy of viruses, just as we struggle to imagine a time before antibiotics.

But will there be drawbacks to success? Just like antibiotics killed bacteria indiscriminately -- good and bad bacteria both -- might we be killing off beneficial viruses too?

Our bodies are rife not just with bacteria but with viruses too. Even when we’re perfectly healthy, we have trillions of viruses inside of us. Scientists are only beginning to survey this viral ecology, but some suspect that it may actually be essential to our health. Many animals depend on viruses. Aphids, for example, need a virus that makes a toxin that prevents wasps from laying eggs inside their bodies. Scientists have found that infecting mice with lymphotrophic viruses protects them from developing diabetes. Other viruses attack cancer cells.

We may have such beneficial viruses inside our own bodies as well, waiting to be discovered. These viruses may not even infect our own cells but could instead be inside the bacteria that colonize us. Some species might keep the populations of their microbial hosts in check, like predators thinning a herd. Some viruses merge with bacteria rather than killing them, providing their hosts with useful genes for feeding or fighting off competitors. All of these microbe-infecting viruses may ultimately help us stay healthy.
It’s conceivable that a broad-spectrum antiviral could devastate this complex, poorly understood biological jungle. As beneficial viruses disappeared, we might pay the price, developing diseases that the viruses used to keep at bay. Even Lingappa concedes that virus-killing could potentially go too far. “I don’t think we want to kill all viruses,” he says. “You only know about a virus when it does something bad. We’ve evolved with them. There’s probably some virus out there doing something good.”

Ten years from now, will we be referring to good viruses and bad viruses? Probably.

Friday, March 23, 2012

Lay off the antioxidants

I think I've had stuff up before warning you off antioxidant supplements. Here is another study - a Cochrane Review - which says that current evidence does not support the use of antioxidant supplements. Indeed certain of them seem to increase mortality.

The abstract is below:

Our systematic review has demonstrated that antioxidant supplements may increase mortality. We have now updated this review.

To assess the beneficial and harmful effects of antioxidant supplements for prevention of mortality in adults.

Search strategy:
We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, the Science Citation Index Expanded, and Conference Proceedings Citation Index-Science to February 2011. We scanned bibliographies of relevant publications and asked pharmaceutical companies for additional trials.

Selection criteria:
We included all primary and secondary prevention randomised clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention.

Data collection and analysis:
Three authors extracted data. Random-effects and fixed-effect model meta-analyses were conducted. Risk of bias was considered in order to minimise the risk of systematic errors. Trial sequential analyses were conducted to minimise the risk of random errors. Random-effects model meta-regression analyses were performed to assess sources of intertrial heterogeneity.

Authors' conclusions:
We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.

Main results:

Thursday, March 22, 2012

Organic Meat? Grass Fed Meat? Hormone Free Meat? Can We Just Have Meat?

You’re a conscientious shopper, you’re already hip to the fact that what you might see at the butcher’s counter is confusing, to say the least, and I’m not referring to deciphering what cuts come from which parts of an animal.

I’m talking labeling on meat.

What does it mean and can we trust it?

What if it’s a choice between organic, grass-fed, hormone- free and no antibiotics? Is an organic, but grain finished cut of beef a better option than a grass-fed and grass-finished cut?


And, might I share, I’m still learning this, too, courtesy of a few small farmers with whom I do business.

First of all, I’m not that keen on giving it all up to the USDA and trusting what they say blindly; far from it. I’ve been told by several independent farmers who stand behind their 100% grass fed product that just having the stamp of USDA Organic is not enough for one to choose that particular piece of meat.

Some things to consider:

USDA Organic meat comes from animals fed 100% organic feed with no by-products, antibiotics or growth hormone, but not only does that mean that the feed could be grain based, there are also no standards in place to assure the consumer that their meat came from humanely treated animals, or humanely-treated workers. In addition, there’s no telling whether the animals were able to forage outside.
Grass Fed conveys that the animal only ever ate grass but how do we do whether it was grain finished? Unless there’s a stamp from the American Grassfed Association, the tag ‘grass fed’ doesn’t mean that antibiotics and hormones were not used. The USDA has a stamp which reads ‘USDA Process Verified/US Grass Fed’ which signifies that they’ve verified a product as being grass fed, but what about the drugs used?
No Antibiotics means the animal was not given antibiotics…when it was alive, but it doesn’t mean that hormones were not used in production.
Certified Humane means that a third party with strict guidelines assesses food, shelter and slaughter, but doesn’t consider hormones or the animal’s ability to forage.

Worse yet, there are even more confusing statements to add the list when you go into fish and poultry labeling!

So how on earth do we know what and where to get our protein?

Honestly, as close as you can get to the source, the better you’re going to be.

No, I am not a hunter myself (although I do want to learn), so I’d say the next best thing is to get to know your local vendors, and get to know them well. I’ve written before about going to the farmer’s market and speaking directly with the fisherman who caught the salmon I’m about to buy, or the rancher who hunted the rabbit I’m planning on using in that night’s stew. I trust those individuals, whose livelihood and entire business is about selling high quality, natural product to the public over the grotesque mega-companies whose interests lie elsewhere…like in their wallets.

Wednesday, March 21, 2012

Neuromuscular Fatigue after a Marathon

Sweat Science

Gina Kolata has an article in the New York Times about how long it takes to recover after a marathon. As she points out, marathons stress many different systems in your body, each of which recovers at a different rate -- glycogen stores, muscle soreness, mental fatigue, and so on. The verdict: nobody really knows how long it takes, though many studies seem to show a return to something approximating full strength after about a week.

The funny thing is, despite these findings, no one would recommend that you tackle another all-out marathon a week -- or even a month -- later. Anyone who has run a marathon knows intuitively that these studies aren't the full story. One possibility is the role of the mind, as Tim Noakes tells Kolata:

So Dr. Noakes relies on the experience of great runners, who tell him that there is a large psychological component to recovery. Many elite marathoners run only one or two races a year. After a marathon, he said, it “probably takes at least six months for the mind to recover fully.”

I'll suggest another possible component: neuromuscular fatigue. When you decide to contract your leg muscle, your brain sends a signal that travels down your spinal cord and eventually reaches the muscle, where muscle fibers contract in response. There's no doubt that running a marathon -- particularly on hilly terrain -- will damage some of the muscle fibers themselves. This is what will result in soreness for the next few days. But even after that soreness is gone, you may not be back to full strength when you try to contract your muscles, because the signal from your brain gets disrupted somewhere before it gets to the muscle -- this is "neuromuscular" fatigue.

A Danish study in 2007 tested the muscular and neuromuscular characteristics of eight marathoners after a race (average time: 2:34:40). Five days later, the runners' maximum voluntary muscular contraction was still reduced compared to pre-race values even though the contractile properties of the muscle itself were back to normal, suggesting that the loss of strength was neuromuscular. Another study, published last year, studied 11 finishers of an extreme mountainous 100-miler: 16 days after the race, most muscle measurements had (surprisingly!) returned to normal, but a couple of measurements ("potentiated twitch" and "potentiation") were still suppressed.

Bottom line: even once you're feeling fine a week or so after the marathon, there may be lingering effects in your body, particularly if you've really gone to the well. We don't know exactly what these factors are -- but if I had a hypothetical all-powerful physiological measurement tool, I'd bet it would still be able to find some markers of fatigue or damage two week

Tuesday, March 20, 2012

Monday, March 19, 2012

Superfoods – Are they really that super?

Coconut oil hailed as a cure for Alzheimers.

Horsegram helps cure type 2 diabetes.

Cocoa found to contain most anti-oxidants.

Honey = health!

So are these claims true? Should we start looking for such superfoods and add them into our diets? Will that fix our problems?

Penny Wise, Pound Foolish

The answer to these questions, like most questions in nutrition is, yes and no. Let me explain.

While it is true that these superfoods contain nutrients (possibly in abundance) that are beneficial to health and that eating these foods along with an anti-nutrient free diet will help fix certain health problems, there is absolutely no benefit in eating these superfoods if you’re basic diet is fundamentally sub-par or inferior from a nutritional standpoint. I don’t think this needs more explanation, but just to be safe, I’ll break this down further.

Let’s say food X is rich in mineral Y and vitamin Z and hence helps in controlling a particular disease condition or improving a certain aspect of health. Now let’s assume that you eat a diet that is dominated by grains, rich in polyunsaturated fats and frequented by sugars. Adding in food X will not help in anyway whatsoever since the abundance of anti-nutrients in your diet will either overshadow any benefit that might result from eating the food or will render the nutrients in food X non bio-available or produce a benefit so trivial (compared to the constant damage from the anti-nutrients) that it is impossible to quantify/monitor progress.

Let’s talk specifics for a minute. Honey is healthful in its pure form and there is no question about that. But adding 2 tablespoons of honey to a diet dominated by wheat, vegetable oils, rice, processed food, sugar etc. will do you absolutely no good. As a matter of fact, this will only hurt you because this addition of honey, implies, not an increase in micronutrient consumption, but only an increase in sugar intake. So is the case with horse gram or spinach or strawberries or coconut oil or ghee or jaggery or any other food that is claimed as a superfood or a ‘health fix’.

On a side note, it is even funnier (actually sadder) when people try to fine tune their cooking methods or cook only using certain metals like copper hoping to reap some health benefits. Seriously? If you’re loading up plastic bags with money and throwing them away, does it matter if the plastic bag costs Rs 10 or Rs 5? If you’re eating a diet filled with junk, does it matter if you cook it in earthenware or eat off a copper plate?
Get your mind right

I’m sorry to burst your bubble folks, but the addition of one food item or cooking a certain way or using certain cooking/eating utensils will not magically convert a nutritionally inferior diet to one that is healthful. Or in other words, topping your cereal/biscuits/oats with honey and almonds won’t make it healthful and neither will eating them off a copper plate.

So, once again, stop looking for shortcuts or magic potions and focus on fixing your diet as a whole. Addition of specific superfoods is something you need to do after your basic diet is legit. It is the icing on the cake… the minutiae as I’d like to call it. Cutting out wheat, vegetable oils and sugars for the most part and basing your diet on real foods is 90% the battle! These changes will have HUGE positive effects on your health and are like money on the table. They’re right there for you to pick up. Make these basic changes first and cnce you’re able to do that, you can then think about focusing on adding in specific foods with specific effects/benefits.

Realize – there are no superfoods. Food, and by that I mean real food, is super! So just eat real food and as always, keep it sane, keep it simple and keep it real.

Sunday, March 18, 2012

Friday, March 16, 2012

Strategic Eating: Solid Protein Is The Answer

A new study in the journal Obesity shows that eating a solid meal will alleviate hunger and keep you feeling satisfied much more than if you drank the same food in a liquefied state—yes, it sounds unappetizing but the liquefied version was made to seem like a normal food. For example, researchers compared a fruit salad served in a bowl, a fruit soup also served in a bowl, and a fruit soup served in a glass to drink (note that the method of delivery, bowl and spoon versus sipping from a glass varied) for a carbohydrate option. Using the same three modes, researchers also tested a protein option using a chicken breast or a chicken soup, and a fat option, using pork belly or a pork belly soup.

Results showed that when participants ate their meal in solid form with utensils, they were more satisfied and had less hunger two hours after eating than if they drank the same meal. The protein meal was most effective at alleviating hunger, raising energy levels, and sustaining feelings of satisfaction. Desire to continue eating was greater after eating the carb and fat meals. Also, after drinking all macronutrient options, desire to eat increased significantly. Hunger levels increased and 80 percent of participants expressed being hungry and having a substantial desire to eat two hours after drinking the meal compared to only 5 percent of the subjects who ate their meal.

Take away from this study the understanding that the structure and macronutrient content of food significantly influences your feeling of fullness and energy level after eating. You want to make the food you eat count, and high-quality protein sources will likely help you be satisfied.

Liquid meals can be convenient and essential after working out in order to take advantage of the immediate “window of opportunity” to feed the muscles and elevate protein and tissue synthesis. But, relying on protein shakes or other liquid meals may not be your best bet if fat loss is a goal. Perhaps eating a protein meal and supplementing with BCAA capsules is a better solution if you often feel hungry shortly after drinking a shake.

Naturally, everyone responds differently to various foods, drinks, and modes of consumption. For best results pay attention to how you respond when you drink rather than eat your meal. Take note of your hunger level if you drink water before or when eating. Drinking water or tea before eating has been shown to decrease the amount people eat, although drinking 250 to 500 ml of water in addition to the liquid and solid meals in this study did not have any influence on hunger or desire to eat.

You have complete control of what you choose to eat. By being aware of how your body responds, you will be able to use that control to your advantage and achieve the best body composition. Make eating a lifestyle habit that is pleasurable and keeps you feeling satisfied and energized

Thursday, March 15, 2012

Wednesday, March 14, 2012

Epigenetics: How Exercise Alters Your DNA

You can't change your DNA. But you can change which bits of your DNA are active or inactive, through what are known as "epigenetic" adaptations. Much of the epigenetic research so far has focused on adaptations that take place shortly before or after birth (which, for example, can increase the probability that a baby born to an obese mother will grow up to be obese). But it was generally thought that the DNA in mature cells like muscle cells didn't change much.

A new study by Swedish researchers in the journal Cell Metabolism challenges that view (full text of study freely available here; press release here; good news article here). The researchers took muscle biopsies from 14 healthy young men and women before and after an incremental treadmill test to exhaustion, and found significant changes in the DNA in their muscles. Specifically, genes involved in energy metabolism were "demethylated" after exercise.

Here's a description (from a Scientific American article on epigenetics, which I quoted in an earlier blog entry on exercise and epigenetics) of what DNA methylation is:

The best-studied form of epigenetic regulation is methylation, the addition of clusters of atoms made of carbon and hydrogen (methyl groups) to DNA. Depending on where they are placed, methyl groups direct the cell to ignore any genes present in a stretch of DNA.

In other words, certain stretches of DNA related to energy metabolism were "switched off" by methyl groups; a single hard workout removed these methyl groups to allow the genes to be expressed. This rapid change in DNA methylation is highly surprising -- scientists are only now beginning to figure out how these epigenetic mechanisms work. A further part of the study showed a dose-response effect: harder exercise produced more demethylation.

So what does this mean? Well, we already knew that training produces major adaptations in your body, so it's not a total shocker. Still, it's a good reminder: DNA isn't destiny.

Monday, March 12, 2012

Starches with Fat

I've been doing some experiments with starches and fats over the last two months. Coincidentally, I've just read some things that have confirmed my initial thoughts.

Stephan just posted an article and there was in interesting quote from Nora Volkow, director of the National Institute on Drug Abuse, talking about low-fat and low-carbohydrate diets:

“The common denominator of such diets is that neither allows consumption of the very caloric and seductive foods that combine high fat with high carbohydrates.”

My experiments over the past two months have been adding butter/oil to either potatoes or rice. When adding butter to potatoes, I noticed that over time the amount of butter I used seemed to creep up. It was if I incrementally wanted more fat, or at least felt I needed more to be satisfied. Then I did the same thing with rice, and once again noticed the same phenomenon. Switching from butter to olive oil made no difference.

I would have to conclude from this that adding oil to starch made it much more appetizing, and probably also led to overconsumption. For example, even if I was not hungry, if I fixed some rice with butter (and often added salt), I could polish it off no problem.

I compared this to when I was in an Asian restaurant in Vancouver the other month. They gave me a huge plate of rice, but it was mostly dry and flavored with pineapple. I couldn't finish it. But I bet if they mixed it with butter I could have.

I know Art Devany has rallied for a lot of years against the combination of sugar/starch with fat. He hypothesized that this was a foreign combination to our hunter-gatherer physiology. I disagree, as nuts combine starch and fat, and nuts were consumed in the Stone Age. But maybe he was right about starch and fat but for the wrong reason. Maybe combining starches with added fat just makes the food that much more appetizing which leads to overconsumption, which then sets off the negative metabolic events.

You could apply the same things to nuts themselves. A couple of people commenting recently at Stephan's blog did some detective work and said:

"Since i started eating primal, the only thing i binge on is salted nuts - mostly dry-roasted.

not unsalted nuts, just salted ones. i can eat 5 oz of salted almonds at one sitting and stop when i feel like throwing up. unsalted almonds soaked overnight? i eat maybe four or five and stop.

so i stopped stocking salted nuts. i don't binge on nuts at all now. Salt makes fatty nuts more palatable to me - so palatable, that i can't control how many i eat."


"I found something similar, so I experimented to see whether the salt or the roasting were to blame. On some days I ate unroasted nuts with salt on them, and on other days I ate roasted, salted nuts with the salt washed off. Neither made me want to eat more than the roasted salted nuts did. From which I concluded that the combination of the salt and the roasting oil was the palatability hook, as the producers planned."

I found this to be true back in 2007 - salted, roasted nuts are are an addictive-like food. So much so, that I just quit buying them and quit eating nuts all together.

Sweat Science 12 Weeks of Training, 12 Week of “Detraining”: What Changes?

This is from a new European Journal of Applied Physiology paper by researchers in Japan and at the University of Laval in Canada. They took six sedentary subjects and had them train an hour a day, five times a week at lactate threshold pace, for 12 weeks. Then they stopped training for 12 weeks. The researchers then analyzed the changes in gene expression in the subjects' muscles, first from 12 weeks of training, then from 12 weeks of detraining.

One thing that's obvious is that, after 12 weeks, most of the training adaptations have disappeared. External changes in traits like VO2max, body composition and muscle fiber type all returned to roughly their starting values. In the gene expression study, 77% of the transcripts that responded to training reverted to their pre-exercise values. This is not surprising: no one expected that you could take 12 weeks off and stay fit.

Still, it's kind of fun to look at the different factors that change. The clear bars show changes with training (upward bars show increased expression; downward bars show decreased expression). Black bars show the changes during detraining; striped bars show the net change after training and detraining. Sugar and lipid metabolism definitely change with training, but the change then disappears. On the other hand, you still have slightly better muscle contraction and protein synthesis expression even after 12 weeks. I don't have any grand conclusions here (other than "you should keep training"), but I thought it was interesting to see the training adaptations broken down into individual components like that.

Saturday, March 10, 2012

The Metabolism Myth

You've heard people say it, maybe you've even said it yourself: "At about 35 my metabolism slowed down, and the fat started to accumulate." The clear inference is that a slowing of metabolism is inevitable, like night follows day. That's simply not true. Men and women, on average, do suffer from creeping obesity; in the Western world, the average 35-year-old male gains about a pound of fat each year until the sixth decade of life. Women often gain proportionately more. The reason, however, is not an aging metabolism.

One Criterion
Energy requirement of muscle remains constant

Exercise Physiology, the excellent textbook by Drs. William D. McArdle, Frank I. Katch and Victor L. Katch (Lea & Febiger, 3rd Edition, 1991), tells us that people do tend to get fatter with age. College-age men average 15% bodyfat and older men are usually about 25%. Women in their youth carry bodyfat about 25% and move up to 35% or more by age 50. The doctors hasten to add, however, that these "average" values should not be accepted as normal. "We believe that one criterion for what is considered 'too fat' should be that established for younger men and women - above 20% for men and above 30% for women. There is probably no biologic reason for men and women to get fatter as they grow older." Increases in bodyfat, they explain, are more a function of activity than age. Inactivity results in loss of muscle. And loss of muscle, not an aging metabolism, is the primary cause of creeping obesity. The muscle that remains is as metabolically active as ever.

Here are the facts as presented by Lawrence E. Lamb, M.D., in his book The Weighting Game (Lyle Stuart, 1988) [see our recommended book list]. Researchers led by Dr. Ancel Keys at the University of Minnesota measured the energy requirements of people of different ages with different amounts of bodyfat. They found that the energy requirement of fat-free body weight (weight of the body minus the bodyfat) were remarkably constant for both men and women between the ages of 20 and 60. All the subjects, no matter what their sex or age, burned about 1.28 calories per hour per kilogram (2.2 lbs.) of fat-free body weight, under resting conditions.

To really understand what's going on here, we need to define "metabolism." Metabolism is the chemical and physical processes in the body that build and destroy tissue and release energy, thereby generating heat. Our metabolism speeds up when we exert ourselves, and we burn more calories. Our metabolism slows down when we are at rest, and we burn fewer calories. But even at rest, it should be emphasized, we continue to expend calories.

It's The Muscle
Reduced muscle mass causes slowing metabolism

It's true: metabolism usually falls with age. In other words, older people on average burn fewer calories per pound of bodyweight than do younger people. But that's because their lean body mass is less.

William Evans, Ph.D. and Irwin H. Rosenberg, M.D. confirm this in Biomarkers, their landmark book about controlling the aging process (Simon & Schuster, 1991) [see our recommended book list]. If you have a reduced amount of muscle, as most middle-aged people do, your metabolic demand for oxygen and your caloric needs decline. That's because muscle tissue is active tissue requiring nourishment. Fat is passive; it just sits there as a storage form of body energy. "We feel that older people's reduced muscle mass is almost wholely responsible for the gradual reduction in their basal metabolic rate."

Vicious Cycle
Slowing metabolism sets up fat gain

Evans & Rosenberg explain that this reduction in muscle mass - and the slowing of metabolism that it causes - sets up a vicious cycle. As our muscle mass falls, our calorie needs fall with it. According to the authors of Biomarkers, most people need to take in about 100 calories per day less each decade to maintain a level body weight. The problem, of course, is that we continue eating the same. "Too many calories coupled with too little exertion, a reduced musculature, and a declining metabolic rate add up to more and more fat." This cycle, they conclude, will only worsen over time - unless broken by a program that increases muscle and restores lost metabolism.

Diet , of course, helps to control creeping obesity. You should avoid calorie-dense foods and emphasize foods high in fiber and bulk. Eat plenty of fruit, vegetables and whole grains. But the main solution for an "aging metabolism" is exercise. Exercise burn calories while you exercise, and after exercise you continue to use more calories than at rest. Even mild exercise leaves you burning extra calories an hour later. If you exercise harder and longer, after 12 hours your energy requirements will still be elevated. And even at rest, your metabolically active muscles still use energy. The more muscle you have, the more calories you use, round the clock. That's why weight training is so important. It builds and maintains the calorie-burning muscle tissue that makes - and keeps - you lean. Lifting weights keeps your metabolic fires burning strongly.

Don't Be Discouraged
Old muscle just as responsive

And don't let anyone tell you that you can't increase your muscle size and strength as you get older. Evans and Rosenberg and their colleagues at the U.S. Department of Agriculture's Human Nutrition Center on Aging at Tufts University have found that "the muscles of elderly people are just as responsive to weight training as those of younger people." Startlingly, an 8-week program of strength training by 87- to 96-year-old women confined to a nursing home resulted in a tripling of strength and a muscle-size increase of ten percent.

Their important conclusion: "Much of the loss of muscle as we age is preventable - and even reversible."

Dr. Lawrence Lamb agrees: "Developing an old muscle is just like developing a young muscle. You may need to be more careful and progress slower, but you can do it." Plus, keep training and pushing to your limit occasionally, and you'll keep your muscles - and your metabolism.

It comes down to this: Your metabolism won't slow down if you don't.

Friday, March 9, 2012

Eliminate Grains In Favor Of Veggies And Fruits To Stay Young And Healthy

Eliminate grains in favor of vegetables, fruits, and nuts to stay young, healthy, and prevent disease. You’ll also have a better body composition and you will probably live longer. If you want to be as healthy as possible, processed and “whole” grains should be removed from your diet. The problem with whole grains is that they contain minimal fiber, are high glycemic, will rapidly raise blood sugar, contain lots of carbohydrates, a small amount of protein, and most have lots of gluten.

It is true that whole grains that are cooked in their hull are going to provide more health and nutritional benefits than processed grains. Be aware that even when a cereal, bread, or pasta package says it’s made from whole grains, that doesn’t mean that you are actually going to get to eat the whole grain since once a grain has been turned into flour, it is no longer “whole.”

Boiled rye, quinoa, or rice may be a better choice than highly processed bread or cereal that has added sugar, high fructose corn syrup, and fortified nutrients that don’t naturally occur in the ingredients. But, a new review in the journal Nutrition Reviews shows that eating whole grains is not the answer to better health or better body composition. Rather, studies suggest that eating more fruits and vegetables in place of grains will give you a leaner body and better health for the long term.

The analysis reviewed 135 research studies published between 2000 and 2010 and found that when you compare diets high in refined grain products (cereal, bread, pasta, pastries) with those that are high in whole grains (cooked grains that are not refined), there is no significant difference in disease risk. Findings show that there is a trend toward eating less fruits and vegetables among people who eat lots of refined grain foods that is in turn correlated with greater obesity, but eating lots of whole grains doesn’t provide much health or body composition benefit.

In contrast, two other large-scale studies, each with more than 15,000 participants, showed a direct link between fruit and vegetable consumption and lower disease risk. A 2007 study published in Public Health Nutrition found that men and women who ate the greatest amount of fruits and vegetables a day had better body composition, lower disease risk, and felt physically better than those who ate the least. Increasing the daily intake of fruits and vegetables by two portions was linked to an 11 percent decreased chance of developing a serious disease.

A 2003 study in the American Journal of Clinical Nutrition also showed that greater fruit and vegetable was linked to lower risk of cardiovascular disease and better body composition. Researchers also looked at refined and whole grain intake in this population and found no positive effect of eating more whole grains on diet except when fruit and vegetable intake was at the highest percentage. The participants who ate the greatest amount of fruits and vegetables and ate whole grains with almost no processed grains had a low disease risk.

Take away from these studies the understanding that if you are going to eat grains, it’s better to eat whole ones than processed ones because processed ones are more likely to have additives and extra fat and sugar. But, to be truly healthy, you should minimize all grains in your diet. Substitute grains with fruits and vegetables. If your goal is to improve body composition, focus on eating vegetables, fruits that are low in fructose and have a low-glycemic index (berries), high-quality unprocessed protein, and including a small amount of nuts in your diet.

Thursday, March 8, 2012

How does having weak muscles affect walking?

This study looks interesting. We often tell people that strength will let them do al things better, being stronger makes everything easier (well I say that in Hillfit anyway)

This abstract is of a study that wanted to test the impact of weak muscles on gait. They did it through various simulations, but it is still instructive. Note that you can apparently get away with weak hip and knee extensors but when the plantar flexors (feet), hip abductors, and hip flexors get weak then your walking will be in trouble.

Think about elderly people if we just got them doing some basic training for these muscles to strengthen them then we could really get their function up.

How robust is human gait to muscle weakness?

Humans have a remarkable capacity to perform complex movements requiring agility, timing, and strength. Disuse, aging, and disease can lead to a loss of muscle strength, which frequently limits the performance of motor tasks. It is unknown, however, how much weakness can be tolerated before normal daily activities become impaired. This study examines the extent to which lower limb muscles can be weakened before normal walking is affected. We developed muscle-driven simulations of normal walking and then progressively weakened all major muscle groups, one at the time and simultaneously, to evaluate how much weakness could be tolerated before execution of normal gait became impossible. We further examined the compensations that arose as a result of weakening muscles. Our simulations revealed that normal walking is remarkably robust to weakness of some muscles but sensitive to weakness of others. Gait appears most robust to weakness of hip and knee extensors, which can tolerate weakness well and without a substantial increase in muscle stress. In contrast, gait is most sensitive to weakness of plantarflexors, hip abductors, and hip flexors. Weakness of individual muscles results in increased activation of the weak muscle, and in compensatory activation of other muscles. These compensations are generally inefficient, and generate unbalanced joint moments that require compensatory activation in yet other muscles. As a result, total muscle activation increases with weakness as does the cost of walking. By clarifying which muscles are critical to maintaining normal gait, our results provide important insights for developing therapies to prevent or improve gait pathology.

Wednesday, March 7, 2012

In Case Refined Cream of Wheat Cereal Wasn’t Enough

I saw an ad for Cream of Wheat brand’s new flavor offerings, which are none other than chocolate and cinnamon bun (aka the shop, Cinnabon, which you’ve likely seen in shopping malls across the country).

Don’t worry, though, as the Cream of Wheat website tells us that we can still “enjoy the rich blend of Cinnabon’s world-famous cinnamon flavor and the warmth of Cream of Wheat” because “Cream of Wheat has always been wholesome and nutritious. Instantly bring the delicious flavor and sweet aroma of Cinnabon into your home with Cinnabon Cream of Wheat“.

Set aside your views on Paleo for a second; is anyone out there really convincing themselves that this is a good idea of something to eat, no less something to eat on its own, first thing in the morning?

I couldn’t think of a worse idea.

Empty stomach + refined sugar surge = insulin spike, subsequent insulin dip and the perfect way to start a day filled with energy crashes, difficulty concentrating, headaches, irritability and telling your body to hang on to any and all extra body fat you so love.

(I hope you’re getting the sarcasm of this…)

Here are the ingredients of what’s being touted as the ‘wholesome and nutritious’ breakfast:



Where are the wholesome bits, then?

Let’s get real.

On the Cream of Wheat homepage, Nabisco even has a pop up that says ‘click here to satisfy your sweet tooth’; wouldn’t that be a message more suited for something being sold as a dessert?

There are so many things that are broken about this, I don’t even know where to begin.

What’s next? Perhaps a Haagen Dasz Breakfast Milkshake? Maybe some Godiva infused pancakes?

Tuesday, March 6, 2012

Why It’s So Important to Keep Moving

Hoping to learn more about how inactivity affects disease risk, researchers at the University of Missouri recently persuaded a group of healthy, active young adults to stop moving around so much. Scientists have known for some time that sedentary people are at increased risk of developing heart disease and Type 2 diabetes. But they haven’t fully understood why, in part because studying the effects of sedentary behavior isn’t easy. People who are inactive may also be obese, eat poorly or face other lifestyle or metabolic issues that make it impossible to tease out the specific role that inactivity, on its own, plays in ill health.

So, to combat the problem, researchers lately have embraced a novel approach to studying the effects of inactivity. They’ve imposed the condition on people who otherwise would be out happily exercising and moving about, in some cases by sentencing them to bed rest.

But in the current study, which was published this month in Medicine & Science in Sports & Exercise, the scientists created a more realistic version of inactivity by having their volunteers cut the number of steps they took each day by at least half.

They wanted to determine whether this physical languor would affect the body’s ability to control blood sugar levels. “It’s increasingly clear that blood sugar spikes, especially after a meal, are bad for you,” says John P. Thyfault, an associate professor of nutrition and exercise physiology at the University of Missouri, who conducted the study with his graduate student Catherine R. Mikus and others. “Spikes and swings in blood sugar after meals have been linked to the development of heart disease and Type 2 diabetes.”

So the scientists fitted their volunteers with sophisticated glucose monitoring devices, which checked their blood sugar levels continuously throughout the day. They also gave the subjects pedometers and activity-measuring armbands, to track how many steps they took. Finally, they asked the volunteers to keep detailed food diaries.

Then they told them to just live normally for three days, walking and exercising as usual.

Exercise guidelines from the American Heart Association and other groups recommend that, for health purposes, people accumulate 10,000 steps or more a day, the equivalent of about five miles of walking. Few people do, however. Repeated studies of American adults have shown that a majority take fewer than 5,000 steps per day.

The Missouri volunteers were atypical in that regard. Each exercised 30 minutes or so most days and easily completed more than 10,000 daily steps during the first three days of the experiment. The average was almost 13,000 steps.

During these three days, according to data from their glucose monitors, the volunteers’ blood sugar did not spike after they ate.

But that estimable condition changed during the second portion of the experiment, when the volunteers were told to cut back on activity so that their step counts would fall below 5,000 a day for the next three days. Achieving such indolence was easy enough. The volunteers stopped exercising and, at every opportunity, took the elevator, not the stairs, or had lunch delivered, instead of strolling to a cafe. They became, essentially, typical American adults.

Their average step counts fell to barely 4,300 during the three days, and the volunteers reported that they now “exercised,” on average, about three minutes a day.

Meanwhile, they ate exactly the same meals and snacks as they had in the preceding three days, so that any changes in blood sugar levels would not be a result of eating fattier or sweeter meals than before.

And there were changes. During the three days of inactivity, volunteers’ blood sugar levels spiked significantly after meals, with the peaks increasing by about 26 percent compared with when the volunteers were exercising and moving more. What’s more, the peaks grew slightly with each successive day.

This change in blood sugar control after meals “occurred well before we could see any changes in fitness or adiposity,” or fat buildup, due to the reduced activity, Dr. Thyfault says. So the blood sugar swings would seem to be a result, directly, of the volunteers not moving much.

Which is both distressing and encouraging news. “People immediately think, ‘So what happens if I get hurt or really busy, or for some other reason just can’t work out for awhile?’” Dr. Thyfault says. “The answer seems to be that it shouldn’t be a big problem.” Studies in both humans and animals have found that blood sugar regulation quickly returns to normal once activity resumes.

The spikes during inactivity are natural, after all, even inevitable, given that unused muscles need less fuel and so draw less sugar from the blood.

The condition becomes a serious concern, Dr. Thyfault says, only when inactivity is lingering, when it becomes the body’s default condition. “We hypothesize that, over time, inactivity creates the physiological conditions that produce chronic disease,” like Type 2 diabetes and heart disease, regardless of a person’s weight or diet.

To avoid that fate, he says, keep moving, even if in small doses. “When I’m really busy, I make sure to get up and walk around the office or jog in place every hour or so,” he says. Wear a pedometer if it will nudge you to move more. “You don’t have to run marathons,” he says. “But the evidence is clear that you do need to move.”

Monday, March 5, 2012

If You’re Busy, You’re Doing Something Wrong: The Surprisingly Relaxed Lives of Elite Achievers

Interesting conclusions…

The obvious guess is that the elite players are more dedicated to their craft. That is, they’re willing to put in the long,Tiger Mom-style hours required to get good, while the average players are off goofing around and enjoying life. The data, as it turns out, had a different story to tell…The time diaries revealed that both groups spent, on average, the same number of hours on music per week (around 50).you’re done be done, and go enjoy the rest of the day.

The difference was in how they spent this time. The elite players were spending almost three times more hours than the average players on deliberate practice — the uncomfortable, methodical work of stretching your ability.

But the researchers weren’t done. They also studied how the students scheduled their work. The average players, they discovered, spread their work throughout the day. The elite players, by contrast, consolidated their work into two well-defined periods…one in the morning and one in the afternoon.

The researchers asked the players to estimate how much time they dedicated each week to leisure activities — an important indicator of their subjective feeling of relaxation. By this metric, the elite players were significantly more relaxed than the average players, and the best of the best were the most relaxed of all…furthemore, the elite players slept an hour more per night than the average players.

The average players are working just as many hours as the elite players but they are not dedicated these hours to the right type of work. And furthermore, they spread this work haphazardly through the day. So even though they’re not doing more work than the elite players, they end up sleeping less and feeling more stressed. Not to mention that they remain worse at the violin.

This analysis leads to an important conclusion… if your goal is to build a remarkable life, then busyness and exhaustion should be your enemy. If you’re chronically stressed and up late working, you’re doing something wrong. You’re the average player…not the elite. You’ve built a life around hard to do work, not hard work

The solution suggested by this research, as well as my own, is as simple as it is startling: Do less. But do what you do with complete and hard focus. Then when you’re done be done, and go enjoy the rest of the day.

Sunday, March 4, 2012

Reheat and Eat – Frozen Primal Meals

Wouldn’t it be great to just open your freezer and have a selection of home-cooked Primal meals ready to heat up? With a little planning, this dream can be your reality. Set aside one day a month when you cook and stock your freezer, or get in the habit of doubling recipes so you can freeze half for later. The majority of Primal recipes freeze well in cooked form. A few exceptions might be cooked seafood, which tends to turn tough and rubbery, and leafy greens and cabbage, which can be limp and soggy when re-heated. Cooked whole eggs typically freeze fairly well (but egg whites alone don’t) and sauces that contain whole cream or coconut milk can be re-heated successfully (although freezing coconut milk alone usually makes it grainy and watery).

Whatever you’re freezing, keep these tips in mind:

Food must be completely cooled before freezing it
Freezing food in small portions helps it freeze quickly, which maintains good flavor and texture
Freezer wrap (thick paper with a moisture-resistant coating) works well for wrapping solid food. Plastic freezer bags work well to store all kinds of frozen food because they take up less room in the freezer than containers and are easy to label.
If using freezer bags, remove all the air from the bag before sealing
Always label the contents and date it was made
Most cooked food tastes best if eaten within 3 months of being frozen
Usually, the best place to defrost food before re-heating it is in the refrigerator
Reheating food that is still frozen and hasn’t been defrosted often takes double it’s regular cooking time in a 350 degree F oven
Food safety regulations recommend re-heating frozen food to an internal temperature of 165 F before eating it

Soups, stews and saucy meals freeze especially well and defrost quickly. Simply place the bag of frozen soup/stew/sauce in a bowl of hot water until it softens and breaks into pieces, then dump it into a saucepan for stovetop heating. These types of meals are also really easy to freeze in small portions (use a small Ziploc freezer bag) so you can re-heat one serving at a time. If you’d prefer to use glass containers to freeze soups and sauces make sure the glass is tempered and labeled freezer safe, otherwise you are likely to end up with broken glass on your hands.

Cooked meat also freezes well, but needs more time to defrost. The best method is to put the frozen meat in the refrigerator the day before you plan to re-heat it.

For meals that you can take out of the freezer and heat up quickly in the microwave without defrosting, try Omelet Muffins and frittata slices. Or, for snacks that you don’t have to warm up at all, try freezing Cocoa and Coconut Snacks, Primal Energy Bars and Primal Trail Mix.

For something more filling, freeze a meal that’s always a hit and really easy to make ahead of time: meatloaf. To keep things Primal, follow any meatloaf recipe you like and just omit breadcrumbs and oats, which are mainly filler and not truly necessary to hold the loaf together (as long as you add eggs). The recipe below is especially simple and results in a moist, flavorful meatloaf that will please kids and adults alike. Freeze the loaf whole, or cut it into slices for individual servings that can be re-heated in the oven or microwave.

Saturday, March 3, 2012


Recently quite a few fitness experts have espoused the benefits of juicing. While I do agree that it can be a good way to increase your produce consumption, if not done correctly it can end up just being an increase in sugar intake with much of the benefits of produce consumption conspicuously absent.

If you are using a juicer that removes the pulp of the fruit or vegetable then you are missing out on the benefits of the entire food – the fiber, some vitamins and minerals and even much of the phytonutrients and antioxidants – while giving you a more concentrated sugar intake. In my opinion that is not a winning combination.

If you are going to juice produce I would recommend using something like a Vitamix or other high-powered blender that will completely liquify the entire produce so you aren’t just getting the juice and sugar. In addition if you are simply blending the entire thing for added produce to your meals then that is totally cool as long as you keep the calorie content in check. If you are doing this as a meal replacement then I would certainly encourage you to add a quality protein and some healthy fats and not do so for more than 1 meal per day, 2 at most on a day where you need something quick.

In the end even if you are blending the entire fruit and/or vegetable, juicing is not the be all end all, it is simply a nice adjunct to a balanced diet based on real, whole, minimally-processed plant and animal foods

Friday, March 2, 2012

Chemicals in our environment and our bodies understands that people don’t want manmade chemicals in their bodies; we definitely don’t. To avoid unwanted chemicals (such as pesticides and heavy metals) in our bodies, we wash our fruits and vegetables to rid them of pesticides and avoid taking huge bites of lead (maybe only little ones). However, a report published by the CDC titled Human Exposure to Environmental Chemicals shows the level of chemicals people have in their bodies. The latest report has 75 chemicals listed; some which may be surprising.

The Human Exposure to Environmental Chemicals report measures the amount of chemicals in blood and urine from a sample group of people and over a number of years. They state that the chemicals they tested for may have found their way into the human body through air, dust, soil, water and food. It also shows if a population has more/less of a certain chemical in their system. For example, their toxicology report states “In the past 15 years, data show that blood cotinine levels for nonsmokers in the US population have decreased about 70%, indicating that public health interventions to reduce ETS exposure have been successful.” The same report also says bisphenol A (BPA), which is linked to reproductive toxicity, has been found 90% of the samples tested. Furthermore, the report states, “the measurement of an environmental chemical in a persons blood or urine does not by itself mean that the chemical causes disease.” While there might be traces of chemicals found in our system, which may or may not be causing harm, do we want them there at all?

For example, one of the herbacides, 2,4- D, was found in concentrations of 12.6 micrograms/L in samples in the 95th percentile. lists this chemical having moderate toxicity, a possible carcinogen and a suspected endocrine disrupter. Another chemical listed 1,4 dichlorobenzene (urinary 2,5 Dichlorophenol) was found in amounts of 473 micrograms/liter in samples in the 95th percentile. 1,4 dichlorobenzene is listed as a known carcinogen in California. So what can we do about this?

On the plus side, however, our bodies are amazing machines that can filter out chemicals that aren’t supposed to be there. Our bodies rid toxins from our system through waste elimination (feces/urine), but there are multiple organ systems at work – like our livers, kidneys, lungs as well as our colon (plus other systems, like our immune system). For those of us that want to keep chemicals in our bodies low, we can keep our organs running efficiently by taking a few simple measures.

Drinking plenty of (filtered) water to help our kidneys flush away toxins, keep caffeine, alcohol and processed foods to a minimum – the less your liver has to do, the better. Sweating also helps remove a trace amount of chemicals, so we can go ahead and add another benefit to exercising. Eat plenty of fresh fruits and vegetables for their vitamins, minerals, phytonutrients, antioxidants and fiber, which will help our immune system and keep a healthy colon. Remember to thoroughly wash your fruits and vegetables and/or buy organic when/if possible.

Thursday, March 1, 2012

Barefoot Versus Running Shoes: Which Is (Surprisingly) More Efficient?


There are three possible headlines for this blog post:

Running in shoes takes less energy than running barefoot.
The heavier your shoes are, the less efficiently you run.
Running barefoot "offers no metabolic advantage over running in lightweight, cushioned shoes."

The topic is a very cool and thought-provoking new study, from Rodger Kram's lab at the University of Colorado, just published online in Medicine & Science in Sports & Exercise (whose official conclusion is Headline Number 3). While there are plenty of subtleties in the study, the basic idea is very simple. They took a group of runners and measured their efficiency (by measuring how much oxygen they consumed at a given pace) while adding progressively larger weights to their feet. They did this both with and without shoes on. Here's what they found:

One of the findings isn't surprising at all: the more mass the researchers added to each foot (using small strips of lead on the top of each foot), the less efficient the runners became. As previous studies have found, every extra 100 grams per foot made the runners consume about 1% more oxygen. That's Headline Number 2 above, and it's a fact that is often cited by advocates of barefoot running: since shoes typically weigh a few hundreds grams, you should immediately become more efficient by taking off your shoes.

But if you look carefully at the graph, you notice something interesting. All the solid dots (shoes on) are lower than the open dots (shoes off), which means the runners were consuming less oxygen while wearing shoes. In fact, the first solid dot (just shoes, no weight added) is lower than the first open dot (no shoes, no weight added). How can this be, if extra weight makes you less efficient?

The inevitable conclusion -- Headline Number 1 -- is that wearing running shoes somehow makes you run more efficiently, independent of the added weight. If you look at equal-weight conditions, the shoes appear to provide a benefit of about 3-4%. The researchers propose two possible explanations for this effect. One is that the runners spontaneously took slightly longer strides (by 3.3% on average) when they were wearing shoes. These longer strides may have allowed them to be more efficient, thought it's unlikely to account for the whole effect. The other is the cushioning in the shoes: without cushioning, the researchers suggest, the runners' leg muscles have to expend metabolic energy to absorb the impact of each stride. They call this the "cost of cushioning" hypothesis.

A few relevant details about the study. The shoes they used were Nike Mayflys, which are very light shoes, with a mass of 135.6 grams for a men's size 9. The 12 runners included in the study were all experienced barefoot runners, running at least 8K (5 miles) a week barefoot or in minimalist footwear. That's not much, but avoids problems with a barefoot learning curve that may have confused previous studies. Finally, all the runners were midfoot or forefoot strikers, both barefoot and in shoes. This condition was imposed to prevent confounding effects from comparing rearfoot to forefoot striking efficiency.

These conditions raise an important caveat. One of the proposed advantages of barefoot-minimalist running is that it automatically helps to correct overstriding -- an extremely common problem among inexperienced runners. The fact that all these runners were already forefoot strikes suggests that none of them were likely overstriding, which would make them less likely to benefit from barefoot running. It's possible that a truly "random" group of runners might have been less efficient in the shod condition, because more of them would have been dramatically overstriding.

Anyway, the bottom line is: this is a surprising result, at least to me. In the long-running debate over running form and running shoes, many of us had started to accept the claim that cushioning in running shoes serves no purpose. But maybe it does, after all. This debate is far from over!