You are a success? The jealous, the envious- they will try to find a way to take you down.

There are always, periodically, flurries of commentary in the media about a high-profile athlete found to have used performance-enhancing drugs. About five years ago, it was Lance Armstrong, the American cyclist who won seven Tour de France. Reexamination of decade-old, frozen body fluid samples yielded evidence of the drug EPO, used to raise the hemoglobin level and so enhance oxygen delivery. An inquiry, which would do justice to the Nuremberg Trials, was launched, and various members of Mr. Armstrong's teams have testified that they saw or themselves used performance-enhancing substances.

Lance Armstrong's resting HR of 35 and Vo2 and other measures were off the chart.

Mr. Armstrong's Tour de France titles were taken away. His sponsors are gone. He was barred from further competition. People say he should "disappear," hide and speak not another word.

So who became the winner of the Tour, those years, 1999-2005, now that Mr. Armstrong has been deleted? The answer is nobody. Why is this? All the riders finishing second, third, and fourth have been or since been identified as users of banned substances.

If you are a champion, if you come to the Final, if you are on the podium, if you set records, you are going to be tested. Many, many times. The blood police knock on your door at 0400. They try to surprise you at a training site in the Pyrenees. If the tests are negative, many still speculate that you must be using something. If you are eliminated in the first heats, finishing 125th in the General classification, bat .235 in AA, you will seldom, if ever, be tested. Nobody cares. Nobody is envious.

There is like a war between athletes seeking advantage, however small, and governing authorities trying to catch them. The pharmaceutical companies play both sides. They sell lots of drugs to suppliers, legal and illegal. They make better and better drugs. They develop masking drugs. Laboratories devise better and better tests. There is a massive "black market". Millions of Americans use these drugs. Rarely is there a clear medical necessity. Reasons are most often "anti-aging" and "quality of life."

I do a search for athletes suspended for using these drugs. I find a list. Hundreds and hundreds. Every country. Many different sports.

I find accounts of the investigation, inquiry into, and prosecution of many prominent athletes. In some instances, the story is going to be bizarre, surreal, and preposterous. Like the saga of the pursuit of one Barry Bonds. Grand Jury? Testimony from his ex-girlfriend! Jail time for his therapist? Twice?

Roger Clemens got off. Many others are not so lucky. Jose Conseco goes to jail. For others, it is the finish of a career. Nobody seems to remember Ben Johnson in a good light. 9.79! Four of those finishing behind him are later caught. Beautiful and talented Marion Jones was harassed, pressured, brought before Grand Juries, and finally put in jail. Her Olympic medals were taken away.

I read about the years of prohibition. Was this a big success? The "War on Drugs" declared by America, is going well? These ideas went/are going well for criminals and gangsters. How many innocents were killed? How many enforcement people were killed? How many millions[billions] are spent for no gain?

The use of performance-enhancing drugs will never be stopped. I say to the authorities: Give it up.

Give Ben Johnson back his medal. Have a celebration for him.

Excuse, Pardon, Sorry to everybody. Give back Marion's medals. Sorry to Jose.

Congratulations to Barry Bonds on a great career. Have a day for him. Put him in the Baseball Hall of Fame, where he clearly belongs. Stop bothering him, and is a trainer.

If Nike were to say, "We are proud to have Lance Armstrong endorse our products," I will buy their stuff forever.

Stop testing anyone. Athlete's choice. Personal choice. Let them decide what and how to use it. Level the playing field. Let every cyclist begin the tour with a hematocrit of 55. You can get this by living at a high altitude. Use the oxygen deprivation tent or room to simulate altitude. Or take the EPO. Let every cyclist who has a bad day try a boost of testosterone.

Instead of using science to improve or avoid detection, Let's use science to study what medication will actually provide an advantage, and if so, what margin? Let's get some data on dose and timing. Let's expand the scientific literature which examines the gains in performance of reproducible tasks resulting from the display of specific agents.

Most importantly, let's educate. Educate the young. What are the risks? What benefits, if any, can be expected? Do the math on the cost. Is there an acceptable reason for taking these drugs? At what age are they contraindicated? This teaching should be part of a high school curriculum.

Lance Armstrong was a gifted athlete. His musculature had an inherited capacity to consume oxygen which was higher than most. This was then pushed to new heights by a training program with an intensity of second to none. There was a dedication, a discipline brought to the table which was unmatched. He sustained this for many years. No detail was overlooked. Diet was a science. His equipment is state of the art. Many sacrifices were made.

Every year, 1999-2005, he came to this event, considered to be the most severe, grueling of physical tests in all sports. For seven years, he won. Did he make sure his hematocrit was optimized? Did he make sure his testosterone levels were on a par with others? I am sure he did. It did not appear to have been too difficult to avoid detection. Mostly a matter of timing. His fellow competitors likewise. Many of them were eventually caught.

Do you think anabolic steroids will make an "average" athlete a great one? Come again. Take a major league baseball player with a batting average of .250, 7 home runs last year, 20 stolen bases and only 14 errors, and muscle him up with testosterone and a weight training program.. The result? Batting average .215, 12 home runs, 2 stolen bases and 35 errors.

I watch some videos of Barry Bonds. At the plate, his stance seems to radiate power. The head is motionless, and the eye seems to slow the pitch and see the spin; he does not swing at pitches outside the strike zone. He takes a walk 232 times in 2002. Then comes the swing; The motion begins at the feet, the weight shifting, the step forward, shoulders turning, the arms follow, then the, finally, the wrists and hands bring the bat through, at a speed never before; a study in grace and fluid power. No drugs can make a Barry Bonds.

I like the idea of personal choice. I don't want to hurt anyone. If I were to try some Winstrol for my bodybuilding, that would be my choice. It is my body. This will not hurt anyone else.

I don't like rules and laws made by non-participants, trying to limit the choices of those who are on the field of play. Sport is a career choice for many. At the highest levels, the difference between success and failure is slim.

For those who succeed, the rewards can be considerable. Failure is a very bad outcome for many. The chips are down.

From your couch, from your office, boardroom, or court, you should make rules and laws and try to enforce them.

For the most part, using anabolics is not banned in bodybuilding. So I don't want to be in a sequence of an illegal, undercover process. I should not have to be. I would like to be able to go to a physician knowledgeable in this area and obtain a legal prescription. I would like to have proper monitoring. I would like to be assured that the product is of high quality. Nobody, including the doctor, should be penalized.

If you take HGH, anabolic steroids or EPO during your athletic career, gain some advantage, carefully control dosing, have regular blood work, and suffer no side effects, that was your choice.

August 2016: After I wrote this, I listened to an endless stream of preaching from the Holier about the cheaters and how they needed to be erased from the face of the earth. I still have no doubt about what I wrote and don't plan to change a word.

Then I found some company in high places: Lewis Kurlantzick, LLB, Zephaniah Swift, Professor of Law at the University of Connecticut School of Law, wrote in his Apr. 12, 2006 article titled "Is There a Steroids Problem? The Problematic Character of the Case for Regulation," published in the New England Law Review:

"Athletes are in a position to make a decision about what behavior is in their best interest, to weigh the risks and benefits according to their own values. And a paternalistic rule that attempts to prevent the athlete from harming himself runs counter to the important values of independence and personal choice. Moreover, it is likely that the feared harm is neither life-threatening nor irreversible. Presumably, under this health rationale, if performance is enhanced by substances that cause neither short-term nor long-term harm to the athlete, these substances should not be banned."

Norman Fost, MD, MPH, Professor and Director of the Medical Ethics Program at the University of Wisconsin, made the following statement in a Dec. 18, 2006 interview published by Scout.com (a Fox Sports News website) titled "Baseball Men - The Skeptic":

"We allow people to do far more dangerous things than play football or baseball using steroids. We allow people to bungee-jump, ski on advanced slopes, to cliff dive. To eat marbled meat or ice cream pie every day if they want. I don't think we want to go down a path in which we restrict and even criminalize behaviors just because they have health risks. And steroids are so low on the list of drugs or diets that cause serious harm I don't understand why we would start there."

Lincoln Allison, DLitt, Founding Director of Warwick University's Centre for the Study of Sport in Society, wrote the following in an Aug. 9, 2004 article titled "Faster, Stronger, Higher," published in the Guardian:

"A sportsman or woman who seeks advantage from drugs just moves up to the level appropriate to his or her underlying ability…

There are no drugs to enhance the human characteristics of judgment and leadership. If there were, would we not want the prime minister to take them? And if there were drugs for hand-eye coordination, would we not pay more to see a performer who had taken them than one who had not?...

In general, the risk to health from performance-enhancing drugs is considerably less than that from tobacco or alcohol, and we ought not to apply paternalistic moral assumptions to a sport that we are not prepared to apply to the rest of life."

Author unknown

Adding Fiber to Your Diet? Here’s Why It’s a Good Idea

Margaret Schwiesow, DO, is a board-certified gastroenterologist with the Mid-Atlantic Permanente Medical Group. She sees patients at the Kaiser Permanente Falls Church and Caton Hill medical centers.






Carbohydrates often get a bad reputation: They have been demonized and are seen as bad for your health. Many fad diets focus on ways to reduce or even eliminate carbohydrates from your plate. But fiber is a type of complex carbohydrate – and getting plenty of fiber in your diet is vitally important to your overall health.

Yet don't try to increase your dietary fiber intake too much, too quickly. Even though getting enough fiber is important, consuming too much fiber too fast can lead to bloating, gas, constipation and other gastrointestinal problems.

So how do you increase fiber in moderation? What's the right amount of fiber for men and women? Why is fiber important? Here are some questions and answers about fiber to help you reap the health benefits of a fiber-rich diet.
What is fiber, and why is it so important?

Dietary fiber is the part of plant foods that the human digestive enzymes can't break down; instead, gut microbes act on fiber and create short-chain fatty acids. Short-chain fatty acids are powerful anti-inflammatory molecules that help prevent many metabolic diseases (obesity-related), coronary artery disease, inflammatory bowel disease and many cancers, including cancers of the colon, esophagus, breast, prostate and ovaries.

In addition to these health benefits of a fiber-rich diet, fiber keeps things moving in our body, ensuring our bowel movements are regular and our stool passes easily. Having enough fiber helps prevent the frustrating symptoms of constipation.

Fiber also plays a key role in keeping our blood pressure, blood sugar and cholesterol levels within healthy ranges, lowering our risk for heart attacks and stroke. Fiber helps us feel fuller, and faster, which helps us eat less and keep our weight within healthy ranges.

Fiber also: Reduces the risk of hemorrhoids
Reduces the risk of developing diverticular disease. Diverticulosis develops when pouches form in the wall of the colon.
Decreases insulin resistance, which in turn lowers our risk of developing Type 2 diabetes

There are two types of fiber, soluble fiber and insoluble fiber. Soluble fiber dissolves in water and has been shown to lower cholesterol.

Insoluble fiber often referred to as roughage keeps stool soft and helps prevent constipation. Insoluble fiber adds bulk to the stool and cleans out the colon. Insoluble fiber may lower your risk of colon cancer and diverticulitis.
How much fiber do I need?

According to the U.S. Department of Agriculture's Dietary Guidelines for Americans, "more than 90 percent of women and 97 percent of men do not meet recommended intakes for dietary fiber."

The average American eats approximately 10-15 grams of fiber a day. This is not enough!

Standard guidelines recommend women eat a minimum of 25 grams of fiber per day and men eat a minimum of 35 grams of fiber a day. In many cases, I encourage patients to get 40 grams of fiber a day to help ward off health problems. Eating at least five servings of fruits, vegetables, whole grains and legumes is the best way to reach these numbers. (This handout lists the fiber content of many foods.)

You may want to keep a food diary for a week to get a sense of how much fiber you are consuming.
What are the symptoms of a low-fiber diet?

The main sign you are not getting enough fiber in your diet is constipation, often defined as having fewer than three bowel movements a week. Other symptoms of a low-fiber diet may include feeling hungry soon after eating, as well as health problems such as weight gain, diverticular disease, hemorrhoids, polyps, irritable bowel syndrome and inflammatory bowel disease.
What foods are good sources of fiber? How can I add fiber safely to my diet?

Depending on your symptoms, your doctor may suggest you add more fiber to your diet. Adding more fiber is something you should do slowly and gradually; don't try to go from eating 15 grams of fiber a day to 30 grams of fiber a day overnight. Doing so causes gas to accumulate in the body, which leads to bloating, belching, abdominal pain and cramps. Adding fiber slowly over the course of weeks and months gives your body time to adjust.

Fiber is only found in plant-based foods. Fiber is found in fruit, vegetables, whole grains, legumes, nuts and seeds. Meat, fish, eggs or dairy products, such as milk and cheese, do not contain fiber.

If you are trying to add more fiber to your diet, consider: Eating more vegetables. Aim for a rainbow of colors. Lycopene-rich reds can include beets, red bell peppers, radishes and tomatoes. Beta carotene-packed oranges and yellows can include carrots, butternut squash, pumpkin, corn and parsnips. Folate- and iron-rich leafy greens include kale, spinach and broccoli. Flavonoid-rich purples include eggplant, red cabbage and purple potatoes. Eating diverse colors will ensure you are getting all your phytochemicals, vitamins and minerals.

Focusing on whole grains. Whole grains include wheat, corn, rice, oats, barley and quinoa. When choosing a cereal or bread, look for whole grains as the first ingredient on the label. I love recommending patients eat plenty of oats, but rather than instant oatmeal, I suggest whole oats, such as rolled oats and steel-cut oats.

Opting for brown rice over white rice.
Eating plenty of fruit. Peaches, bananas, kiwi, raspberries, apples, oranges and pears are good fiber sources. Eat the skin.

Eating more legumes, such as beans, lentils, chickpeas, soybeans or split peas.
Adding nuts and seeds to your food.

Reducing the amount of packaged, processed foods in your diet. These foods generally have little nutritional value and little-to-no fiber.

When adding fiber to your diet, drink at least 64 ounces of water a day. This is essential to ensuring that fiber gets properly absorbed in your body. If you add fiber without adding water, you may feel extremely uncomfortable.

Many patients ask whether they should try fiber supplements. The answer? It depends. Most healthy people should be able to add fiber to their diet without using supplements, but people with certain health conditions may benefit from fiber supplements. Talk to your physician about your unique circumstances.
Is there anyone who should eat a low-fiber diet?

A low-fiber diet may be suggested for a short period of time after certain bowel surgery or radiation, bowel obstruction due to a tumor or inflammatory bowel disease, acute diarrhea or when preparing for a colonoscopy procedure. This should be done under the supervision of a physician or a dietitian. A low-fiber diet is not recommended long term because it can cause additional health and gastrointestinal problems.

Overall, eating a diet rich in fiber has many long-term health benefits: lowering your risk of heart disease, stroke, Type 2 diabetes and several cancers. And fiber helps regulate your cholesterol, blood sugar and weight. Adding just a few grams of fiber a day can pay off in the long run. If you need help, talk to your physician.

Does Gatorade Do What It Says It Does?

 What's in Gatorade?

Click to Watch

Drinks like Gatorade make a lot of claims — but are they real? Food scientist Topher McNeil reveals what sports drinks really do to the human body.

Carl Sagan and the Freedom to Doubt, Monday July 11, 2022, The Boston Globe

 

Carl Sagan and the freedom to doubt  In astronomy, “Sagan’s number” refers to the number of stars in the observable universe. That’s a value easier to define than to calculate, but in round numbers, according to a 2010 study by Yale astronomer Pieter van Dokkum, it comes to 300,000,000,000,000,000,000,000, or 300 sextillions. (Depending on the meaning of “observable,” that number may now be out of date.) Sagan’s number is named for Carl Sagan, the American astronomer, planetary scientist, cosmologist, and science communicator who died in 1996. He achieved extraordinary renown in the 1970s and 1980s, especially after PBS broadcast his 13-part television series “Cosmos,” which became one of the most widely watched series in the history of American public television. (The dazzling volume of the same title produced as a companion to the series was among the best-selling science books ever published.)  His scientific achievements were considerable. He published more than 600 papers and books in the areas of astrobiology, planetary conditions, the origins of life on earth, the greenhouse effect, and extraterrestrial intelligence. He played a role in numerous NASA planetary space probes and helped write the so-called Arecibo message, an interstellar radio signal incorporating information about humanity that was beamed from the earth in the direction of the M13 star cluster in 1974. The honors and awards he received numbered in the dozens; they ranged from the NASA Distinguished Public Service Medal to the George Foster Peabody Award for his television work. He was a frequent guest on The Tonight Show with Johnny Carson, and he wrote regularly about science for Parade magazine, a weekly supplement in hundreds of US papers.

As part of his campaign to increase scientific literacy among the general public, Sagan repeatedly emphasized the importance of skepticism and non-dogmatic thinking. He was adamant that extraordinary claims require extraordinary levels of proof and derided pseudoscience and its peddlers. (One of his favorite cartoons, he wrote, showed “a fortune-teller scrutinizing the mark’s palm and gravely concluding: ‘You are very gullible.’”)  Yet while he cast a cold eye on the supernatural claims of religion, he was equally firm that scientists must not fall in love with scientific claims that aren’t supported by convincing evidence. “If the ideas don’t work, you must throw them away,” he wrote in The Demon-Haunted World, the last book he published before his death. “Don’t waste neurons on what doesn’t work. Devote those neurons to new ideas that better explain the data.” He warned against succumbing to confirmation bias — what the pioneering 19th-century English physicist Michael Faraday described as the temptation   to seek for such evidence and appearances as are in the favor of our desires, and to disregard those which oppose them. . . . We receive as friendly that which agrees with [us], we resist with dislike that which opposes us; whereas the very reverse is required by every dictate of common sense. The lure of confirmation bias is if anything more powerful today when social media and political polarization relentlessly turn scientific matters into culture-war flashpoints. On issues as different as gender identity and COVID-19, too many ideologues on both the right and the left approach public health and science questions through a political lens. News organizations increasingly freeze out or belittle scientific opinions that don’t fit an accepted narrative. Leading politicians support or oppose healthcare practices on the basis of party politics. Were Carl Sagan still alive, he would surely be among those pushing back against such blind antiscientific bias. Alas, he was just 62 when he died from complications brought on by a long struggle with bone marrow disease. But in a recently unearthed speech he gave to the Illinois chapter of the American Civil Liberties Union in 1987, Sagan expressed warnings that are even more relevant today than they were at the time. The speech was obtained and transcribed by Harvard scientist Steven Pinker and civil liberties lawyer Harvey Silverglate, both of Cambridge, Mass., who published it this month in the online journal Quillette.  In his address, write Pinker and Silverglate in a brief introduction, Sagan “spoke prophetically of the irrationality that plagued public discourse, the imperative of international cooperation, the dangers posed by advances in technology, and the threats to free speech and democracy in the United States.” If those threats raised concerns in 1987, they have grown dire today. Some excerpts from Sagan’s remarks:   Science has devised a set of rules of thinking, of analysis, which, although there are exceptions in individual cases (scientists being humans just like everybody else), nevertheless, on average, are responsible for the remarkable progress of science. And you all know, certainly, what these rules are. Things like arguments from authority have little weight. Like contentions have to be demonstrable. Like experiments must be repeatable. Like vigorous substantive debate is encouraged and is considered the lifeblood of science. Like serious critical thinking and skepticism addressed to new and even old claims are not just permissible, but is encouraged, is desirable, is the lifeblood of science. There is a creative tension between openness to new ideas and rigorous skeptical scrutiny. These are axiomatic to the scientific method, yet they are flouted routinely, even aggressively. Sagan properly noted that “arguments from authority have little weight” — yet how often are controversial matters now declared immune to dispute because “the science is settled” or “ 97 percent of scientists agree” or we must “listen to the experts”?   Skepticism, said Carl Sagan, is "the lifeblood of science."  What is true of science is true of everything, Sagan argued. Mistakes are inevitable, which is why it is urgent to allow space for “settled” conclusions to be challenged:   In public affairs, this sort of error-correction machinery in our society is institutionalized in the Constitution. It’s institutionalized, first of all, in the separation of powers, and secondly, in the civil liberties, especially in the first 10 amendments to the Constitution: the Bill of Rights. The founding fathers mistrusted government power, and they had very good reason to, as do we. This is why they tried to institutionalize the separation of powers, the right to think, the right to speak, to be heard, to assemble, to complain to the government about its abuses, to be able to vote or impeach malefactors out of office. . . . Despite our best efforts, some things we believe are probably wrong. We certainly are very keen on recognizing the errors of past times and other nations. Why should our nation, and why should our time, be different? If there are things that we believe, if there are institutions in our society that are in error, imperfectly conceived or executed, these are potential impediments to our survival. How do we find the errors? How do we correct them? I maintain: with courage, the scientific method, and the Constitution. At the intersection of science and public policy, nothing is more hazardous than dogmatism enforced through the squelching of dissenting attitudes. A generation before Sagan voiced his warning, an equally renowned scientist, the theoretical physicist Richard Feynman, raised similar alarms.  In a 1955 lecture to the National Academy of Sciences, Feynman — who a few years later would be awarded the Nobel Prize in Physics — addressed what he called “the value of science.” He ended with a warning, more desperately needed now than it was then, against closed-mindedness in science and against the urge to demonize those who challenge popular views. “If we want to solve a problem that we have never solved before, we must leave the door to the unknown ajar,” Feynman told his listeners.    In the impetuous youth of humanity, we can make grave errors that can stunt our growth for a long time. This we will do if we say we have the answers now, so young and ignorant as we are. If we suppress all discussion, all criticism, proclaiming “This is the answer, my friends; man is saved!” we will doom humanity for a long time to the chains of authority, confined to the limits of our present imagination. It has been done so many times before. It is our responsibility as scientists, knowing the great progress which comes from a satisfactory philosophy of ignorance, the great progress which is the fruit of freedom of thought, to proclaim the value of this freedom; to teach how doubt is not to be feared but welcomed and discussed, and to demand this freedom as our duty to all coming generations. Of all scientific values, Sagan and Feynman both knew, the most invaluable is the freedom to doubt. That freedom is no less indispensable to a healthy civic culture. In a universe of 300 sextillion stars, we will never know everything we don’t know. Even here, on the pale blue dot that is the only home humankind has ever known, there are so many unsolved dilemmas, so many questions with only uncertain answers. Those who demand that heterodox thoughts be censored — or self-censored — are playing with fire. For when skeptics aren’t safe, all of us are at risk.

N.C. recruit dies after medical episode during pre-employment fitness test

By Leila Merrill GREENSBORO, N.C. — A Greensboro Fire Department recruit died Wednesday morning after suffering a medical episode during the pre-employment fitness assessment, WFMY reported. Andrew Vaughn, 36, was finishing the last lap of a 1.5-mile run when he collapsed. He reportedly said that his legs were cramping and he could not stand. Fire officials said the assessment includes the run, plus sit-ups, push-ups and pull-ups, with the run being the first in the series. He was scheduled to join the department’s recruit class on Sept. 1. In a statement, Greensboro Fire Chief Jim Robinson said, “this is an absolutely tragic day for the fire service, Andrew’s family, and his wife, Stephanie. … The Greensboro Fire Department is devastated by Andrew’s untimely death. Our hearts go out to everyone who knew and loved him. Please respect the family’s privacy during this difficult time.”

The U.S. Forest Service's Morale Crises

By Marisa Gerber Staff Writer June 17, 2022 6:30 AM PT “We are facing a dire retention issue,” an exasperated firefighter wrote in his viral resignation letter this spring. “We are losing people at a terrifying rate.” In a story this week, my colleague Alex Wigglesworth showed that the letter written by a squad boss of the elite Truckee hotshot crew for the U.S. Forest Service was only the latest example of how dire the crisis of confidence has become among federal wildland firefighters. Morale, several current and former firefighters told her, was at an all-time low — the byproduct of low pay, mental trauma and the exhaustion of battling ever more destructive fires. Forest Service firefighters, typically classified as forestry technicians, have a starting annual base salary of somewhere between about $25,000 and $32,000. President Biden’s infrastructure bill signed into law in November called for the creation of a new classification and an increase of either $20,000 or 50% — whichever was less — in areas deemed hard to recruit or retain personnel in, but after more than six months no raises had yet been given. “We’re getting paid $15 an hour to put our lives on the line,” said one firefighter who recently left the agency. Such departures are only compounding the increasingly dire personnel shortages. As California braces for another brutal fire season, only 62% of federal firefighter positions here are filled, according to a source within the agency. Officials recently announced that they’d been unable to fill some 1,000 temporary firefighter positions and were now looking to make emergency hires by shortening the onboarding process. According to a recent survey of more than 700 current and former wildland firefighters, nearly 80% of respondents reported mental health issues they attributed to the stresses of fighting fires. An assistant engine operator told The Times that, due to low pay and trauma, he was thinking about retiring. He’d already gotten a second job to try to make ends meet — now working 80-hour weeks — and he said experiencing close calls, as well as the deaths of co-workers, had affected his mental health.

Is cold exposure beneficial for metabolic health?

Peter Attia, MD

When I was in Norway in February 2020, I shared on Instagram that a friend and I were experimenting with cold exposure by spending about 20 minutes outside in a wind chill of roughly -10°F. Our hope in putting ourselves through such misery? Activation of brown fat.

What is cold exposure therapy?

Cold exposure therapies are forms of short exposure to cold temperatures (which don’t have to be as extreme as Norway in mid-winter). Cold showers, ice baths, open water swimming, and even short walks in cold weather are all forms of cold exposure therapy. Goals of cold exposure therapy include boosting energy expenditure and improving metabolic health. Though the precise activities and durations may vary, for the purpose of improving metabolic health, cold exposure therapies are all rooted in the same simple rationale: production of heat (known as “thermogenesis”) requires an expenditure of energy. In cold environments, the body must produce more heat to maintain its temperature, thus burning more calories. One mechanism by which mammals are known to produce heat is through skeletal muscle shivering. Another is known as “nonshivering thermogenesis” and relies principally on a specialized type of adipose tissue called brown fat.

To learn more about both cold exposure therapy and heat therapy, check out AMA #16.
What is brown fat?

Brown fat, or brown adipose tissue (BAT), gets its name from its difference in color relative to white adipose tissue (WAT), which constitutes the vast majority of fat in the human body. Unlike WAT, BAT contains a high concentration of iron-rich mitochondria, which, in addition to giving the tissue a brown color, make BAT far more metabolically active than WAT. The mitochondria in BAT are unique from those in other body tissues, however. Instead of harnessing energy and converting it to chemical forms (ATP) that the cell can use to support its normal functions, BAT mitochondria are designed to “waste” energy in the form of heat.

When mammals are exposed to cold conditions, the sympathetic nervous system releases norepinephrine, stimulating brown fat to burn energy and create heat to maintain core body temperature. Smaller mammals lose heat easily due to their relatively high surface area to volume ratio, and thus need to generate more heat to maintain core body temperature against cold environments than larger mammals. For this reason, small rodents have been used extensively to study BAT, since BAT activity contributes up to 60% of nonshivering thermogenesis enabling survival in winter conditions. One study found that an eight-week constant exposure to 41°F led to a 42% increase in nonshivering thermogenesis capacity over control mice housed at 72°F. In another study, hairless mice housed at an ambient temperature of 50°F for four weeks had 3x more BAT by percent body weight than their counterparts housed at 86°F (1.5% compared to 0.5%).

How important is brown fat for humans?

In humans, the thermogenic capacity of brown fat is most important during infancy. Newborns, like other small mammals, have a high surface area to volume ratio and a relatively low quantity of insulating WAT at birth. Therefore, it makes sense that about 5% of a newborn’s body weight is BAT, a much higher percentage than adults. As we age, we lose a lot of the brown fat with which we were born and transition to muscle shivering as the predominant form of thermogenesis in cold conditions. However, small deposits of brown fat persist through adulthood in vital regions of the body, especially around the neck and upper shoulders.

In humans, BAT volume cannot be measured directly, as BAT cells are intermingled with WAT cells and other tissues. Instead, BAT volume is estimated from measurement of BAT metabolic activity. The gold standard for measuring BAT activity in laboratory studies is positron emission tomography-computed tomography (PET/CT) imaging, in which 18F-fluorodeoxyglucose (18F-FDG), a radionuclide marker for glucose, is used to visualize glucose uptake in BAT. When activated, BAT increases its uptake of glucose and free fatty acids from the bloodstream, acting as a “metabolic sink” to fuel thermogenesis. BAT is thus identified as areas of adipose tissue that show high levels of 18F-FDG uptake – indicating high metabolic activity.

18F-FDG studies have shown that BAT activity in humans increases with cold acclimation. Young adults underwent a ten day protocol of acclimation to intermittent, mildly cold temperatures of 60°F. BAT activity was measured before and after the acclimatization with 18F-FDG PET/CT during a more acute cold exposure, just above the threshold for shivering. After acclimatization, glucose uptake increased, nonshivering thermogenesis increased from 10.8 to 17.8%, and the subjective experience of cold became more comfortable over the ten-day period. In addition to the increase in BAT activity, there is also evidence from rodent studies that suggest that cold exposure may cause BAT induction, where WAT cells become more “brown-like.” This process – termed “beiging,” has limited and inconclusive evidence in humans for short-term cold exposures. However, there is some evidence that long-term, regular cold exposure promotes this type of WAT-to-BAT transition in humans.
Measuring Brown Fat Activity

For my self-experimentation in Norway, I was not going to have a PET/CT scan following my stint in the cold, so instead I used an infrared camera to capture a thermal map of my skin surface.



As you’ll hear us discuss in the video below, the measurement of BAT activation is based on a “delta” – or the change in the thermal measurements before vs. after cold exposure. And it turns out, I had the largest change in BAT activity in response to the cold!

Impact of BAT Activation on Energy Expenditure

So how much of a difference can BAT activation make for overall energy expenditure? The estimated mass of BAT in adults is small, ranging from 10-300g (whereas WAT mass is typically 13.5-18 kg for a normal weight adult male). It is estimated that 50 g of BAT is responsible for roughly 5% of resting energy expenditure, or 75-100 kcal per day. During short-term mild cold exposure, when BAT is most active, glucose uptake per gram of BAT is greater than uptake per gram of skeletal muscle. However, skeletal muscle mass far exceeds BAT mass, so in considering each of these tissues in total, BAT is not going to have nearly the effect on metabolism that skeletal muscle has. This is clear from measurements of energy expenditure changes during cold exposure: while overall energy expenditure increases up to 250-300 kcal/24 h, the contribution of BAT activity accounts for <20 kcal/24 h, even in individuals with relatively high amounts of BAT. The remaining increase in energy expenditure is attributed to thermogenesis in skeletal muscle.

The Bottom Line.

Cold exposure therapies are based on a known and reliable mechanism of BAT activation. Even seasonal changes in temperature have been correlated to increased BAT activity. Still, despite the high metabolic capacity of active BAT, its overall contribution to total energy expenditure is fairly small in adults. Indeed, even when looking exclusively at cold-induced increases in energy expenditure, BAT activity contributes only a relatively small percentage compared with both shivering and nonshivering activity in skeletal muscle. In other words, the rationale for cold therapies may be valid at a cellular, mechanistic level, but it falls apart when we consider the minuscule impact that cold-induced BAT activation has on whole-body energy expenditure in humans.

It’s possible that cold exposure therapies may also influence alternative pathways besides BAT, which might account for the observed effects of these practices on inflammation and the cardiovascular, endocrine, and nervous systems. Further, pharmacological interventions may someday be capable of activating BAT and/or triggering beiging of WAT to a far greater extent than appears possible by cold exposure, potentially opening the door for BAT activation to become a viable option for driving meaningful increases in energy expenditure. But when it comes to using cold exposure therapies to activate BAT, the benefits are likely too small to make any difference for metabolic health. It appears that my suffering in Norway was to no avail for health. But hey, at least I left with some pretty unique bragging rights.

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