More Sobering Crap About Sitting

We all keep seeing reports about the dangers of sitting (and clearly, I can't stop blogging about it), but everyone keeps their butt cheeks glued to the couch anyway. According to this new article in the New York Times, most of us spend "50 to 70 percent" of our lives sitting -- mostly at work or in front of our television sets.

Is TV really that good? Perhaps. I, for one, have spent many an hour planted in front of the boob tube, gazing slack-jawed at the glowing images on the screen. But check this out:

Every single hour of television watched after the age of 25 reduces the viewer’s life expectancy by 21.8 minutes. By comparison, smoking a single cigarette reduces life expectancy by about 11 minutes, the authors [of an Australian research study] said. 

Looking more broadly, they concluded that an adult who spends an average of six hours a day watching TV over the course of a lifetime can expect to live 4.8 years fewer than a person who does not watch TV.

Those results hold true, the authors point out, even for people who exercise regularly. It appears, Dr. Veerman says, that “a person who does a lot of exercise but watches six hours of TV” every night “might have a similar mortality risk as someone who does not exercise and watches no TV.”

Guess I'll have to catch up on episodes of The Walking Dead while standing up.

Sleep Like A Caveman?

Over at Conditioning Research, Chris Highcock recently posted about "Paleo Sleep" and a fascinating (albeit twelve-year-old) study of how hunter-gatherers  sleep. Some of the sweeping conclusions about "instinctive" sleeping postures seem a bit too rigid and not particularly applicable to those of us who sleep indoors ("Tribal people do not like lying on the ground in the recovery position while wearing no clothes as the penis dangles in the dust and can get bitten by insects"), but the conclusions offer a lot of food for thought:

• Forest dwellers and nomads suffer fewer musculoskeletal lesions than “civilised” people;

• Nature's automatic manipulator during sleep is the kickback against the vertebrae by the ribs when the chest is prevented from movement by the forest floor;

• Various resting postures correct different joints;

• Pillows are not necessary.

The researchers point to anecdotal evidence that "low back pain and joint stiffness is markedly reduced by adopting natural sleeping and resting postures," and call for more observation and research in this area. This study's a dozen years old, so I wonder what the latest research has to say about optimal sleep postures.

Personally, I've slept on the ground (and hardwood floors) before, and can't say I loved the experience. I'm pretty sure I'm not going to give up sleeping in a bed...but then again, I once said the same thing about eating pizza.

Knocking Down Straw Men

I'm about to unleash a Paleo rant, so if you hate this stuff, move along. These aren't the droids you're looking for.

A very good friend of mine sent me a link this morning to a piece on NPR.com by anthropologist Barbara J. King entitled "The Paleo-Diet: Not the Way To a Healthy Future." In it, she argues that ancestral eating approaches are nothing more than a "paleo-fantasy" with no scientific roots in paleo-anthropology.

I'm a budding Paleo nerd, so the headline got me excited. I eagerly scanned the article, hoping to learn more about King's position. I love a good argument.

But sadly, there are no good arguments in King's piece. In fact, there's barely any comprehensible argument at all. Even worse, King's article never lives up to its title; there is no discussion of why the Paleo diet is "not the way to a healthy future." Instead, King simply sets up a straw man to knock down, painting a picture of Paleo as a dogmatic, homogenous effort to reenact caveman life (which it isn't), and then dismissing the benefits of ancestral eating because: (1) it doesn't accurately reflect prehistoric diets, (2) humans can survive eating lots of different things, and (3) it's not environmentally friendly. Along the way, she claims that "science" trumps the evidence bolstering Paleo nutrition, but then fails to cite to any actual science at all. Just in time for Halloween, this is an opinion piece masquerading as science journalism.

Here are King's specific claims, and my responses to each of them:

Argument 1: "Our ancestors began to eat meat in large quantities around 2 million years ago, when the first Homo forms began regular use of stone tool technology. Before that, the diet of australopithecines and their relatives was overwhelmingly plant-based, judging from clues in teeth and bones. I could argue that the more genuine 'paleo' diet was vegetarian."

Me: Sure, based on the fossil record, early hominids may have been primarily plant-eaters. But later hominids like Australopithicus afarensis (who lived from 3 to 4 million years ago) and Homo erectus (1.3 to 1.8 million years ago) developed jaw structures and teeth to eat meat. In other words, our distant ancestors may have been vegetarians by necessity -- but as soon as they could get their hairy paws on animals, they ate 'em up. And so we've been eating meat for millions of years.

Oh, and by the way, it's disturbing that King -- a biological anthropologist who throws around her "scientific" knowledge on this topic -- doesn't seem to know when the Paleolithic era took place. The Paleolithic is defined as "the prehistoric era distinguished by the development of the most primitive stone tools discovered." That's why it's also known as the Stone Age. King herself points out that our ancestors started eating meat when we started using stone tools roughly 2 million years ago. So if the Paleolithic era began 2 million years ago, and that's when we started "eat[ing] meat in large quantities," how can she argue that "the more genuine 'paleo' diet was vegetarian"?

My head hurts.

(And not to get all technical and stuff, but there's evidence that stone tools were being used up to 3.4 million years ago -- so the Stone Age stretches back farther than many had thought.)

Argument 2: "More worrisome are persistent attempts to match a modern diet to an 'average' Paleolithic one, or Loren Cordain's insistence that 'we were genetically designed to eat lean meat and fish and other foods that made up the diet of our Paleolithic ancestors.' Here's where science most forcefully speaks back. First, ancient hunter-gatherer groups adapted to local environments that were regionally and seasonally variable -- for instance, coastal or inland, game-saturated or grain-abundant (eating grains was not necessarily incompatible with hunter-gatherer living)."

Me: King sets up the straw man argument that we're trying to "match a modern diet to an 'average' Paleolithic one," but she conveniently ignores that we're actually not trying to "match" anything at all, let alone a single, inflexible menu.

King doesn't seem to understand that Paleo -- at least the way most of us approach it -- is not about strict historical re-enactment. Rather, "Paleo" is just a convenient label -- a shorthand. Perhaps a better way to put it is that we're trying to eat foods that are whole and unprocessed, and avoid those that are inflammatory or metabolically damaging. (Read Chris Kresser's take on the Paleo template. He articulates this point much better than I ever could.) It so happens that hunter-gatherers -- regardless of their foraging strategy or local environments -- ate this way, and didn't eat cupcakes and guzzle soy milk. But it doesn't mean we're trying to precisely replicate the eating patterns of actual cavemen. Cavemen diets give us a starting point -- a hypothesis. They're not the end-all, be-all.

And although King pays lip service to the notion that "leaders of the paleo-diet movement don't think monolithically," she then immediately makes the assumption that Loren Cordain's "The Paleo Diet" is the ancestral eater's Ten Commandments. Her statement that "lean meat...takes center stage" and that Paleo eating is "homogenous" is wrong and outdated; many -- if not most -- Paleo eaters these days recognize the value of good dietary fats. Even Cordain has acknowledged that his "lean meat" recommendation needs revision.

Further, it's bizarre that King is trying to make the point that Paleo eaters don't eat seasonally like our ancestors did. After all, seasonal foods are emphasized in most Paleo approaches.

Finally, although King argues that "eating grains was not necessarily incompatible with hunter-gatherer living," there's no evidence of any hunter-gatherer society that relied on grains as a staple of their diet. By definition, hunter-gatherers are not farmers, and wild grains -- even if abundantly available -- are not edible absent harvesting and processing. The vast majority of hunter-gatherer societies didn't eat grains, and those that did didn't lean heavily on 'em -- until they became agrarian societies. After all, a hunter-gatherer society that begins farming the land isn't a hunter-gatherer society any longer.

[UPDATED: In the comments below, Lizzy points out that there's evidence of Paleolithic grain-eaters. Some hunter-gatherer societies began transitioning to herder-farmer patterns during the Upper Paleolithic. It's fascinating stuff, but in the end, I'm not sure it matters. Again, the intent of most modern Paleo eaters isn't to replicate actual cavemen diets -- it's to eat in a way that promotes optimal health. To the extent we're trying to eat like cavemen, then, we're trying to eat like the ones that didn't eat craploads of pro-inflammatory stuff.]

So just how is "science...forcefully speak[ing] back"? King never explains.

Argument 3: "[G]enes were not in control. People learned what worked in local context for survival and reproduction, and surely, just as in other primates, cultural traditions began to play a role in who ate what... Genes no more 'designed' our eating behavior than they designed our language or our ways of relating between the genders."

Me: In blanket fashion, King asserts that "genes were not in control" -- that human biology does not play a role in our bodies' reactions to food. If she's going to make the argument that human genetics plays no role in human metabolism or immune reactions to different foods, she'd better be able to back it up. After all, there are scores of studies -- cited by Cordain, Robb Wolf, Mat Lalonde, etc. -- that say the exact opposite. (Did King look at any of the research?) Let's face it: We aren't meant to eat certain things. Just because something is edible doesn't mean we can thrive on it. Does King really believe that our bodies can optimally process anything and everything we eat regardless of our biology?

(In case you're wondering, the monstrosity pictured above is Paula Deen's Savannah High Apple Pie. I wouldn't recommend incorporating it into your diet -- even if it's readily available or culturally appropriate.)

Again, King doesn't explain. Rather, she just says that "people learned what worked in local context for survival and reproduction." Duh. People made do with what was around. And even today, an enormous swath of the population on this planet subsists on gluten-packed foods that wreak havoc on their immune systems because wheat is cheap and available. But "surviving" and "thriving" aren't the same thing. Just because a person can live long enough to have sex and pump out a kid doesn't mean he or she enjoys optimal health.

Case in point: The photo above is of Donna Simpson, the New Jersey mom who's trying to become the fattest woman in the world.

Argument 4: "It's not paleo-fantasy that's going to help us negotiate a healthy future, the 7 billion of us together, on this environmentally-endangered planet."

Me: King's a vegetarian. [UPDATED: I take it back: King says she hasn't made "a complete commitment to vegetarianism because of some medical dietary issues." She admits to eating some chicken, but feels "increasingly bad about it" and is "working on cutting back."] And like many (but by no means all) vegetarians, she associates meat-eating with environmental destruction.

Look -- I agree wholeheartedly that factory farming practices are wasteful and environmentally unsustainable. The horrific conditions in factory farms has produced terrible health consequences, including antibiotic-resistant super-bugs and e. coli outbreaks. Unsustainable fishing practices are equally destructive, wiping out entire ecosystems. But is the solution to simply stop eating animals? Is vegetarianism the one true path to sustainable eating?

I don't think so. As John Durant points out, there are implications of a modern vegetarian food system that are just as terrible for the environment.

Wheat, soy beans, and corn (all vegetarian staples) are being grown in vast industrial monocultures using fossil fuel fertilizers. These methods still have an enormous cost in animal life from giant threshers, pesticides, fertilizers, and destruction of habitat. A vegetarian world is no ethical or environmental paradise. Even if people stopped eating animals (though the global trend is to eat more animals, not fewer), you’d have a one-time reduction in the size of these monocultures. But you’re still left with industrial farming. Books like Meat: A Benign Extravagance by Simon Fairlie and The Vegetarian Myth by Lierre Kieth cast doubt on the pessimistic statistics that eco-vegans have been throwing around, nay-saying sustainable alternatives. So how do you actually create a more sustainable alternative?  

King doesn't even pretend to answer this question. She engages in name-calling instead, labeling Paleo as a "fantasy" because humans don't need to eat like cavemen to survive. But King never bothers to explain why she thinks eating whole, unprocessed food is unhealthy. Nor does she offer any reasons why she thinks the Paleo diet is any less sustainable than any other contemporary diet.

I would argue that our family's diet of meat and vegetables -- primarily from local farms and CSAs -- is more healthy and ecologically sound than that of a vegetarian family that shops for Tofurky, Wheat Thins and Bagel Bites. Is it more expensive to buy grass-fed meats and pastured eggs? Yes. But consider why wheat, soy, and corn-containing processed food products -- including vegan and vegetarian-friendly options -- are so inexpensive. It's not because they're cheap to develop, produce, market and transport; it's because government subsidies are propping up these environmentally devastating crops. If you're a rational environmentalist, you can't praise small farms that raise vegetables for food on the one hand and condemn small farms that raise animals for food on the other. Likewise, you can't just rail against factory farming without also ripping into the industrial food complex that pushes corn, soy, and wheat to the detriment of our health and environment.

But instead of railing against subsidies to industrial agribusiness, King chose to lob a grenade at Paleo -- something she clearly hasn't bothered to thoroughly research. Why didn't King pen a screed against industrial food production and in favor of eating whole, unprocessed foods instead? Could it be that she has a bone to pick with an increasingly popular nutrition approach that advocates eating (gasp!) meat?

Hey, NPR: I hope you know that this is making me less likely to participate in your local station's pledge drive. (But I still love you, Terry Gross and Ira Glass.)

Okay, rant over. Time to get back to farting yoga videos.

[Previously: I See Dumb People]

This Is Not Okay

Yesterday, M showed me this tweet by @SFoodie, the food blog run by SF Weekly:

This made me want to reach into the Internet and throttle the writer for: (1) poor reading comprehension skills, (2) sloppy reporting, and (3) irresponsibly handing people a "science-based" excuse for ignoring a potentially life-threatening health problem.

Let's be perfectly clear: The study referenced in the tweet DOES NOT SAY THAT BEING FAT IS HEALTHY.

The real story? Canadian researchers looked at whether people with high Body Mass Index (BMI) scores are uniformly at high risk for an early death. To test this, they looked at a bunch of people they classified as "obese" BASED ON THE SUBJECTS' BMI SCORES, ranked their health according to the Edmonton Obesity Staging System (EOSS), and compared mortality rates. A subject with an EOSS score of 0 was one who showed no problematic symptoms, while a person with a score of 4 (the highest possible score) was one with severe chronic diseases and disabilities.

The conclusion? Not all folks with high BMIs are at risk of early death.

This is not rocket science, folks. A high BMI tells you absolutely nothing about the state of a person's body composition or health. A muscle-bound person with little body fat might have a very high BMI and a flabby "skinny fat" smoker might have a "normal" one, but it doesn't mean that the former is obese any more than it means that Michael Jackson was a super-healthy fella. Body mass should not be mistaken for body fat. And while the researchers (unfortunately) used "high BMI" interchangeably with "obesity," let's be real: When most people think about obesity, the dictionary definition comes to mind -- and it's all about "excessive accumulation and storage of fat in the body."

Take elite CrossFit firebreather Rob Orlando. His BMI is above 29, which puts him in borderline "obese" territory. But does he look fat to you? Would you use the word "obese" to describe him?



Let's face it: BMIs are completely useless as an indicator of health. And in fact, this is precisely what the Canadian researchers were seeking to show. As a recent CNN article pointed out, "[t]he main question was whether BMI alone could determine who dies early, said Dr. Arya Sharma, the lead author [of the study]." Unsurprisingly, the answer was "no." (Duh.)

You wouldn't know it from the articles written about the study, though. SF Weekly's article, for example, looks like this:

That's right: "[Y]ou can have your cake, eat it, and, um, have some more."

And this wasn't an outlier. Other "respectable" publications wrote headlines like:

• "Being Obese Not Necessarily Bad" (Toronto Sun)

• "Obese And Healthy: Not All Overweight People Need To Worry" (The Huffington Post)

• "Study: It's Okay to be Fat" (Voice of America)

• "Study: Obese People Live as Long as Slimmer People" (WebMD).

• "Obesity Police Busted? Study Says Fat Folks Can Be Healthy"(CBS News)

Similarly, Facebook and Twitter lit up with further distortions of the study's conclusions:

No one's going to spend even a minute on Google to track down the original study. They're not going to hear that BMIs are bunk. But they will take away the message that "being fat can be GOOD for you" -- so why worry?



P.S.: WTF, Barry Sears?

Sleep or Die

Tired of my harangues about the importance of sleep? Too bad. Suck it up.

Tonight, let’s look at what happens once you drift off into slumberland, and dive in a little deeper into why it’s so damaging to your health (and fitness goals) when you don’t get enough shut-eye.

Typically, over the course of a night, your body and brain goes through a series of anywhere from four to seven sleep cycles. If uninterrupted, each cycle takes about 90 to 110 minutes, and consists of several distinct stages:

• Stage 1: This initial stage of light sleep (which occurs only when you go from a conscious state to an unconscious one) lasts about 5 or 10 minutes, during which you drift in and out of sleep. Your muscles relax (except when your whole body twitches and you get that sudden “OH CRAP, I’M FALLING!” sensation -- it's called hypnic myclonia, by the way) and your eye movements slow down. You can be awakened pretty easily during Stage 1 sleep; when that occurs, you usually don’t recognize that you fell asleep at all.

• Stage 2: In this second stage of the sleep cycle, which lasts for a half-hour or so, you’re still in light sleep, but your body temperature drops a bit. Also, your eye movements, respiration, heart rate and brain waves slow considerably – interrupted by just a few occasional bursts of rapid brain waves. Fully half of your total sleep time is spent in Stage 2 sleep, which is also called “spindle sleep” because of the spikes (or spindles) in brain activity. These spindles, incidentally, are critical to the brain’s ability to process information.

• Stage 3: When you enter Stage 3 (some experts separate this into two stages – 3 and 4 – but for our purposes, let’s just lump ‘em together), you’re in deep sleep. Your brain begins producing much slower, high-amplitude “delta” waves. When you’re in deep sleep, there’s basically no eye movement or muscle activity. (This is also the time when some kids experience sleepwalking or bedwetting.) It’s very difficult to be awakened from deep sleep – but if you manage to be roused, you’ll likely feel disoriented and out-of-sorts for a while.

• REM Sleep: Rapid eye movement distinguishes REM sleep from the other stages. But it’s not just your eyes that move faster -- during this period, your heart rate increases, blood pressure rises, and breathing becomes rapid, irregular and shallow. Brain waves during REM sleep increase to levels similar to those during regular waking hours, and most of your dreaming occurs during this stage.

Now: What happens if your sleep is interrupted, or you don’t get enough sleep?



If you’re awakened -- by noise, light, your own snoring, your alarm clock -- and you go back to sleep, you actually start over again at square one: Stage 1 sleep. If this happens within the first few minutes of sleeping, no harm, no foul; after all, your head just hit the pillow a few minutes ago. But if some disturbance awakens you while you’re in Stage 2 sleep or beyond, you’ve just deprived yourself of some valuable Stage 3 and REM sleep.

The same goes for inadequate sleep. Go to sleep too late or wake up too early, and you’re missing out on the full benefits of a full night’s rest -- and exposing your mind and body to a host of risks.

What risks, you ask?

First and foremost, lack of sleep can lead to obesity, diabetes and premature aging.

Research suggests that chronic sleep deprivation “may influence weight through effects on appetite, physical activity, and/or thermoregulation,” and that it's linked to the development of type II diabetes. The link between lack of sleep and insulin resistance is clear:

In laboratory studies of healthy young adults submitted to recurrent partial sleep restriction, marked alterations in glucose metabolism including decreased glucose tolerance and insulin sensitivity have been demonstrated. The neuroendocrine regulation of appetite was also affected as the levels of the anorexigenic hormone leptin were decreased, whereas the levels of the orexigenic factor ghrelin were increased. Importantly, these neuroendocrine abnormalities were correlated with increased hunger and appetite, which may lead to overeating and weight gain. Consistent with these laboratory findings, a growing body of epidemiological evidence supports an association between short sleep duration and the risk for obesity and diabetes.

In other words, your metabolism is wrecked and your appetite goes haywire.

This appears to be especially the case if your Stage 3 deep sleep is restricted or interrupted -- even if your total sleep time remains the same. A University of Chicago study concluded that suppression of slow-wave “delta” sleep resulted in significant decreases in insulin sensitivity, which leads to reduced glucose tolerance and increased risk for type II diabetes.

Even a single night of partial sleep deprivation can induce insulin resistance in otherwise healthy individuals.

As Robb Wolf put it:

Sleep deprivation mimics many elements of the aging process. One could make the argument that how you feel when you are sleep deprived is likely how you will feel if you are both diabetic and old (sleep deprivation dramatically impacts insulin sensitivity). Improved sleep time and quality will help you: Lean out, avoid depression, autoimmunity, heart disease... It might even help you be a better athlete.

Stephan Guyenet has similar stuff to say:

Besides making us miserable, lack of sleep appears to predispose to obesity and diabetes, and probably sets us up for the Big Sleep down the line. I can't say I'm surprised, given how awful I feel after even one night of six hour sleep. I feel best after 9 hours, and I probably average about 8.5. Does it cut into my free time? Sure. But it's worth it to me, because it allows me to enjoy my day much more.

Want more? Sleep deprivation will jack up your cortisol -- the hormone released by your adrenal glands in response to stress. “Even partial acute sleep loss” can negatively “affect the resiliency of the stress response and may accelerate the development of metabolic and cognitive consequences of glucocorticoid excess.” If you accumulate high levels of cortisol overnight, you’re more likely to be insulin resistant during the day, which in turn will derail your body’s efforts to efficiently process glucose. Your diet may be clean, but heightened cortisol levels will negate all your awesome Paleosity. Plus, chronically elevated cortisol levels have been linked with decreases in muscle tissue and bone density, elevated blood pressure, and lowered immunity. Fun!

Wait -- what did you say? Oh, so you’re lean and insulin sensitive and a super-kick-ass athlete and think you can therefore get by with less sleep? Consider this: Studies show that even a “relatively low degree of sleep disturbance” can disturb the natural secretion of human growth hormone (HGH) that occurs while you sleep.

Sleep deprivation also impairs your body’s ability to recover from your crazy metcon beatdowns. According to U.C. San Diego study, lack of sleep results in reduced levels of Interleukin-6 (IL-6) -- a cytokine that triggers an immune response to trauma -- including normal microtraumas from exercise.

Not enough to convince you? Okay -- how about this: Another effect of sleep deprivation is lowered testosterone. That's right: Sleeplessness is not a sign of virility -- it's the exact opposite.

Want to get bigger, stronger and faster? Get enough sleep.

For those of you who care about your noggins, there's even more to consider: Sleep deprivation will rob you of the brain-related benefits of REM sleep, which is essential for processing and managing everything from information and memories to emotions and stress.

Even if you like to pride yourself on being a lunkhead who cares not a whit about your brainpower or emotional well-being, think about this: REM sleep is the period when your brain transfers the muscle movements you learn from your short-term memory into your long-term memory. Your hippocampus downloads information to your neo-cortex so that you can recall -- among other things -- how to perform physical skills. In other words, don’t waste your time trying to perfect your snatch technique if you’re not going to get enough sleep.

Check out this handy infographic for more about the risks of sleep interruption and deprivation:

(Click the image above for the full picture.)

The upshot? Go to bed early. Try to wake up without using your alarm clock, or use an alarm that'll gently rouse you rather than jolting you awake. (Gadget hounds: Try the Lark or Zeo.) Worried you won't wake up in time for your early morning meeting or workout? THEN GO TO BED EARLIER. Make sure you keep your room pitch-black -- no nightlights, no glowing LCD displays on your cell phone, clock, DVD player. Cover 'em up if that's what it takes. Get blackout curtains. The light's bad for you and contributes to you getting fatter. And no, I’m not kidding.

I know I’m guilty of not always often practicing what I preach. (I'm still awake right now, after all.) I recognize that I'm skating on the edge of being chronically sleep deprived. But I want to turn that around. Part of why I wrote this post was to convince myself to get my butt into bed earlier.

So I'm off to bed. Are you?

Chill Out

At the scorching-hot South Central Regionals this year, the temperature remained well over 100 degrees for all three days of competition. Even the blacktop on which athletes competed looked like it was going to melt. Ice was a precious commodity. And yet the firebreathers did what they always do: Kick ass and take names.

But is it possible that an ice pack around the neck could've helped to further boost athletic performance?

The answer appears to be yes -- but only up to a point.

According to the New York Times, researchers have found that "cooling the neck before exercise in hot, humid conditions can improve athletic performance." In a recent study, volunteers were recruited to run in a heated room until exhaustion; those who wore cooling collars didn't perceive the heat as much, allowing them to push themselves to run farther before they ran out of gas.

In this experiment, even though the runners’ bodies grew warmer when they wore the collars, their minds weren’t registering that fact, and they reported feeling no hotter than without the collars. Cooling the neck, the authors concluded, had allowed the runners to continue exercising as their core temperatures rose, improving their time to exhaustion “by dampening the perceived levels of thermal strain.”

...[I]t is likely that the collars cooled the blood in the neck’s carotid artery, which then flowed to the brain to produce a “subsequent lowering of cerebral temperature” and convince the brain that the body was cooler than it really was.

As the lead researcher points out, if "you are fit, competitive and ferociously intent on outdoing your training partners," using a cooling collar may help you "improve performance and capacity" in high-heat environments.

But before you rush out to buy a cooling collar before your next summer workout, consider this: You might fool your brain into thinking it's not as hot as it is, but once your body hits a certain temperature, you could very well suffer from heatstroke -- or worse. Being able to perceive your body temperature is a good thing -- it signals your brain to "shut down the muscles before disaster occurs."

In study after study, when the core body temperature of someone who is exercising nears a critical point, usually above 104 degrees, that person’s ability to continue abruptly ends. You feel absolutely exhausted and stop, before heatstroke sets in.

Fooling your brain to gain a competitive edge could backfire disastrously, so use your noggin before you decide to give this hot-weather performance aid a shot.

[Source]

How to Take a Kick to the Crotch

How does one survive a sledgehammer kick to the nuts?

Rod Sacharnoski, Creator of Combat Ki: "When I first began taking kicks to the testicles, there was a lot of fear involved. So I started to develop a system where I could get myself to higher levels of accepting the pain and nausea. It takes about five years of good training."

And what does that "good training" require? Lots and lots of kicks to the balls. You know, so you can get used to it.





Science is cool. But:

• I'm not sure it makes sense to take thousands of kicks to the groin in order to...withstand a kick to the groin.

• Trust me: You will not be kicked in the testicles with such frequency and force that you must devote five years of your life to prepare for its eventuality. Of course, this assumes that you're not: (1) a belligerent drunk, (2) an MMA fighter, (3) a hand-to-hand combat specialist, (4) a bouncer, (5) a stuntman, (6) a ninja, (7) a total asshole, or (8) a teenage boy. (And if you are all of the above, I salute you, sir.)

• Even if you are, in fact, highly prone to having a foot lodged in your crotch, it's far cheaper and less painful to BUY AN ATHLETIC CUP. They cost, like, five bucks at Walmart. Even the fanciest ones'll set you back less than $25.

• Kicking each other in the nuts may look like a pleasant way to pass the time, but don't try this at home, kids. It's all fun and games until someone loses a testicle.

Human Turd Burgers

Has it really come to this?



As I was watching this video, I kept thinking: This isn't Paleo. But heck, I guess if you're willing to eat fake meat MADE OUT OF HUMAN EXCREMENT HARVESTED FROM RAW SEWAGE, I guess the addition of red dye and soy protein is the least of your worries.

Plus, I have to give the brains behind this revolting initiative, Professor Mitsyuki Ikeda, style points for: (1) brandishing a super-creepy plastic hand pointer with red nail polish, and (2) going nuts with the office labeler. (Look closely: The guy's obviously fond of the words "SHIT BURGER.")

One last thing: Is it just me, or is that poo really weird-looking?

[Source]

I See Dumb People

Bon Appétit recently published a piece entitled "We're Calling B.S. on the Paleolithic 'Lifestyle' Trend." The headline sounded juicy -- I love a good debate, and am open to new evidence or compelling arguments. So, Bon Appétit, fire away! What've you got?

Argument No. 1: "We will note that Fred Flintstone, patriarch of the modern stone age family, wasn't exactly trim."

Wait -- what? That's a joke? Aren't jokes supposed to be funny? Besides, the Flintstones ate like crap. Hit me with the real stuff.

Argument No. 2: "Forsaking all dairy and bread for nuts and berries to recreate a body that flourished when middle age meant 15 years old just doesn't make sense to us."

That hoary myth again? Read this. Or this. Or this. Or this. Or this. What else have you got?

Argument No. 3: "While we may not have biologically evolved all that much, our intellectual development has brought us a greater scientific understanding of the nutrients our bodies need to be healthy."

Oh, good. Although I kind of wish you'd actually clued us in on the "greater scientific understanding" that's led to significantly better health outcomes across Western civilization, perhaps I'm quibbling. I'm SO glad that Type II diabetes, autoimmune disorders and metabolic syndrome are a thing of the past, and that obesity rates have plummeted worldwide. Wait -- what? They haven't? We're fatter and sicker than ever? Hmm. That's weird -- especially with all that mysteriously unspecified "scientific understanding" and all.

Okay, Bon Appétit, I know you're saving the best for last. Sock it to me.

Argument No. 4: "10,000 years ago, food was pure nourishment, a necessity and nothing more. We now have advanced to a place where eating is more than just consumption: food is culture, history, art, and science, all on one plate. Pomegranates are Pom Wonderful!"

WHAT DOES THAT EVEN MEAN? Are you saying that avoiding processed breakfast cereals, Pop-Tarts and Pizza Hut's Stuffed Crust Pizza in favor of real, whole foods is an affront to art and history, and threatens our very cultural fabric? Because if so, I'm pretty sure you're the bullshit artist.

Also? What you said about Pom Wonderful MAKES NO SENSE. Did anyone even proofread this thing? How did a piece that says absolutely nothing -- other than "the Paleo Diet is clearly bullshit because, well...it sounds kinda weird to me" -- get published by a prominent food periodical?

My wife then interjected with an even better question -- this one, posed to me:

"Why are you paying attention to what Bon Appétit says?" M asked. "That magazine's even dumber than Cooking Light."

Good Meat is Dead Meat (Not Meat That Was Never Alive)

PETA has announced that it's offering a $1 million reward to "the first scientist to produce and bring to market in vitro meat."

According to PETA, test tube meat would be super-awesome because it'd "mimic flesh and could be cooked and eaten" without hurting any animals. Of course, only the unwashed meat-addicted hordes would need to eat the stuff:

[H]umans don't need to eat meat at all -- vegetarians are less likely to get heart disease, diabetes, or various types of cancer or become obese than meat-eaters are -- and a terrific array of vegetarian mock meats already exist. But as many people continue to refuse to kick their meat addictions, PETA is willing to help them gain access to flesh...

(Wrong, wrong, wrong. But I digress.)

I can't wait to supplement my "terrific array" of Tofurky patties and Quorn chunks with a big, juicy slab of lab-generated, vat-grown, 100% processed "meat." I mean, who could resist a steak that looks this appetizing?

Who's with me?

Stop With The Egg Whites

The New Yorker's food issue is out this week, and it features a lengthy piece about April Broomfield, the chef/owner of NYC's The Spotted Pig and The Breslin -- both of which are awesome for meat-lovin' Paleo eaters like me. Last month, M and I hit The Breslin for brunch, and ordered two full English breakfast plates, piled high with porky goodness, and with no beans or toast to spoil the fun.

We clearly did not do an adequate job of educating one of our brunch companions about the place, though. And as I mentioned in a previous post, he's not on the Paleo train. After scouring the menu in vain for something -- anything! -- that the USDA Food Pyramid and conventional dietary wisdom would smile upon, he asked our server whether the vegetable frittata could be made with egg whites. "No," she replied.

Of course, the server's intent wasn't to steer him towards better health. Chances are, she subscribes to the same beliefs that most people hold about the dangers of egg yolks and saturated fats and everything else on The Breslin's menu. I seriously doubt she's read Gary Taubes.

But you know who has? Director/producer/screenwriter/novelist Nora Ephron. She most certainly would not have asked for fucking egg whites.

Ephron was being interviewed by Michael Krazny on NPR's "Forum" this morning. I know next to nothing about Nora Ephron, other than that she wrote "When Harry Met Sally" or something, so I was only half-listening -- until Krazny gently chided her about her position on eggs and cholesterol. My ears perked up.

"Eating the cholesterol in eggs doesn't raise your blood cholesterol!" she countered. Krasny shot back that the Mayo Clinic says she's wrong. She stuck to her guns. And she happens to be right.

Here's what I dug up from an old HuffPo blog post of Ephron's on the subject:

[D]ietary cholesterol has nothing whatsoever to do with your cholesterol count. This is another thing I've known all my life, which is why you will not find me lying on my deathbed regretting not having eaten enough chopped liver. Let me explain this: you can eat all sorts of things that are high in dietary cholesterol (like lobster and cheese and eggs) and they have NO EFFECT WHATSOEVER on your cholesterol count. NONE. WHATSOEVER. DID YOU HEAR ME? I'm sorry to have to resort to capital letters, but what is wrong with you people?

Which brings me to the point of this piece: the egg-white omelette. I have friends who eat egg-white omelettes. Every time I'm forced to watch them eat egg-white omelettes, I feel bad for them. In the first place, egg-white omelettes are tasteless. In the second place, the people who eat them think they are doing something virtuous when they are instead merely misinformed. Sometimes I try to explain that what they're doing makes no sense, but they pay no attention to me because they have all been told to avoid dietary cholesterol by their doctors. 

According to yesterday's New York Times, the doctors are not deliberately misinforming their patients; instead, they're participants in something known as an informational cascade, which turns out to be a fabulous expression for something that everyone thinks must be true because so many reputable people say it is. In this case, of course, it's not an informational cascade but a misinformational cascade, and as a result, way too many people I know have been brainwashed into thinking that whole-egg omelettes are bad for you.

So this is my moment to say what's been in my heart for years: it's time to put a halt to the egg-white omelette.

Hear, hear.

David H. Freedman wrote in this month's Atlantic about how the health studies you hear about on the news are almost universally fraught with error and bias -- and then the information cascade takes over and we go flying off the cliff with all the other lemmings. So what happens when another study comes out and draws the opposite conclusion -- which, by the way, happens ALL THE TIME?

Too late. We're already in freefall -- and we didn't even get to enjoy the frittata with the awesomely delicious egg yolks.

Get Smart

Exercise helps keep your brain sharp:

[S]cientists [at Northwestern University] have been manipulating the levels of bone-morphogenetic protein or BMP in the brains of laboratory mice. BMP, which is found in tissues throughout the body, affects cellular development in various ways, some of them deleterious. In the brain, BMP has been found to contribute to the control of stem cell divisions. Your brain, you will be pleased to learn, is packed with adult stem cells, which, given the right impetus, divide and differentiate into either additional stem cells or baby neurons. As we age, these stem cells tend to become less responsive. They don’t divide as readily and can slump into a kind of cellular sleep. It’s BMP that acts as the soporific, says Dr. Jack Kessler, the chairman of neurology at Northwestern and senior author of many of the recent studies. The more active BMP and its various signals are in your brain, the more inactive your stem cells become and the less neurogenesis you undergo. Your brain grows slower, less nimble, older.

But exercise countermands some of the numbing effects of BMP, Dr. Kessler says. In work at his lab, mice given access to running wheels had about 50 percent less BMP-related brain activity within a week. They also showed a notable increase in Noggin, a beautifully named brain protein that acts as a BMP antagonist. The more Noggin in your brain, the less BMP activity exists and the more stem cell divisions and neurogenesis you experience. Mice at Northwestern whose brains were infused directly with large doses of Noggin became, Dr. Kessler says, “little mouse geniuses, if there is such a thing.” They aced the mazes and other tests.

Whether exercise directly reduces BMP activity or increases production of Noggin isn’t yet known and may not matter. The results speak for themselves. “If ever exercise enthusiasts wanted a rationale for what they’re doing, this should be it,” Dr. Kessler says. Exercise, he says, through a complex interplay with Noggin and BMP, helps to ensure that neuronal stem cells stay lively and new brain cells are born.

So don't be stupid: Get up and exercise.

(Source: The New York Times)

A Revised Myth

The New York Times reports that according to a new mathematical formula used to calculate a woman's maximum heart rate, women who are trying to push themselves hard during exercise can actually push a little less hard:

[R]esearchers at Northwestern Medicine in Chicago announced a new formula for calculating a woman’s maximum heart rate, a measure commonly used by athletes to pace themselves and monitor their progress. In a study of nearly 5,500 healthy women, scientists discovered that a decades-old formula for calculating heart rate is largely inaccurate for women, resulting in a number that is too high.

The news may be a vindication to many women who have struggled to keep up with lofty target heart rates espoused by personal trainers and programmed into treadmill displays.

The commonly used formula subtracts a person’s age from 220. But based on the data collected in the Chicago study, the right formula for calculating a woman’s maximum heart rate is a little more complicated: 206 minus 88 percent of a woman’s age.

The findings are significant because many runners, cyclists and other exercisers obsessively monitor their heart rates by taking their pulse and rely on the old formula to gauge the intensity of the workout. The typical goal is to stay within 65 to 85 percent of the estimated maximum heart rate, depending on whether the athlete is trying to build aerobic capacity or increase endurance.

But the new study shows that for women, the number typically derived from the standard formula is far off the mark. Using the old formula of 220 minus age, a 40-year-old woman would achieve an average maximum heart rate of 180 beats per minute. That means her pulse should stay around 153 beats per minute during her workout to achieve a target heart rate of 85 percent.

But based on the new calculation, the same woman’s average maximum heart rate is 171 beats per minute, meaning her desired target heart rate is just 145 beats per minute, 8 beats a minute slower than under the old formula.

But if you're someone who's "obsessively" checking your heart rate during your workouts, you know you can stop, right? Constant monitoring of your heart rate is unnecessary. If you exercise regularly, you can judge how hard you're pushing yourself, and can instinctively ramp your intensity up or down accordingly. Unless you're: (1) completely new to exercise and want to get a baseline sense of how hard you're working, or (2) a highly-specialized athlete doing some very specific training to gain a particular (marginal) boost in performance, your heart rate monitor's just a high-tech distraction from your workout.

Besides, as I've mentioned before, the "target heart rate zones" posted on treadmills and elliptical machines are utter bullshit. (Want more on this subject? Read this and this.)

So in the end, what does the new formula for calculating women's max heart rates tell us?

Not too much.

The Myth of the Fat Burning Zone

I'm shocked and dismayed by the fact that even now -- years after the "Fat Burning Zone" myth has been debunked -- cardio equipment manufacturers continue to propagate this garbage.

Just about every treadmill or exercise bike you've ever seen has a chart on it showing users how hard to push themselves to achieve their chosen fitness goals. According to charts like the one pictured below (which are often programmed into the electronic guts of the cardio equipment), you're in the "fat burning zone" if you're exercising at 50 to 60 percent of your maximum heart rate, and you're in the "cardio training zone" if you're at 75 to 85 percent of your maximum heart rate.

This is bullshit.

For weight loss purposes, the theory goes, it's counterproductive to work too hard; instead, you'll optimize your fat loss if you take it easy and work out less intensely. According to this argument, low-intensity aerobic training forces your body to burn more fat as an energy source, while high-intensity cardio work burns more sugar and less fat. As New York Times reporter Gina Kolata summarized in her excellent 2003 book, "Ultimate Fitness: The Quest for Truth about Exercise and Health":

The idea is that if you want to get rid of fat, you should force your body to burn it. Muscles prefer to use sugar, in the form of glycogen, for energy, because it is so easy to metabolize. but they also can use fat. The fat-burning-zone hypothesis says that if you don't push yourself too hard, your muscles will burn fat and you will lose weight. Extreme exertion, however, will force your muscles to burn glycogen, leaving your body's fat intact.

Sound too good to be true? It is.

Here's the real deal: While it's true that a higher proportion of calories burned during low-intensity exercise comes from your flab (approximately 60 percent versus 35 percent from high-intensity workouts), higher intensity exercise still burns more calories from fat overall. Kolata writes:

It turns out that the myth of low-intensity-exercise fat burning is a misunderstanding of a basic relationship, best seen on a graph. One line shows muscles' use of fat as an energy source as a function of exercise intensity, and another line depicts muscles' use of carbohydrates as a function of exercise intensity. the crossover point, where equal amounts of fat and carbohydrate are being burned, comes at about 60 percent of your maximum effort, or a heart rate that is about 70 percent of maximum. After that, the amount of carbohydrate burned exceeds the amount of fat, and this imbalance increases as exercise intensity increases. If you guet to your maximum heart rate, less than ten percent of the calories you burn will come from fat.

That led to the argument that as long as you keep your heart rate low enough, you will burn more fat than carbohydrates and you will lose more weight. The problem is that the argument is neglecting a crucial component: the number of calories burned. The harder you work, the more energy you expend, and the more calories you will need.

In other words, who cares if a greater percentage of your calories are burned from fat than from sugar/carbs? What really matters is the total number of calories you burn from fat. And the more intense the exercise, the more total calories (from both fat and carbs) you'll burn.

So suck it, "Fat Burning Zone" charts.