Your dominant frequency is how many times per second your brain pulses alpha waves

Thursday, January 24th, 2019

Magnetic EEG/ECG-guided Resonant Therapy, or MeRT, aims to return a person’s brain to the beat of its natural information-processing rhythm, or its dominant frequency:

Your dominant frequency is how many times per second your brain pulses alpha waves. “We’re all somewhere between 8 and 13 hertz. What that means is that we encode information 8 to 13 times per second. You’re born with a signature. There are pros and cons to all of those. If you’re a slower thinker, you might be more creative. If you’re faster, you might be a better athlete,” Won says.

Navy SEALS tend to have higher-than-average dominant frequencies, around 11 or 13 Hz. But physical and emotional trauma can disrupt that, causing the back of the brain and the front of the brain to emit electricity at different rates. The result: lopsided brain activity. MeRT seeks to detect arrhythmia, find out which regions are causing it, and nudge the off-kilter ones back onto the beat.

“Let’s just say in the left dorsal lateral prefrontal cortex, towards the front left side of the brain, if that’s cycling at 2 hertz, where we are 3 or 4 standard deviations below normal, you can pretty comfortably point to that and say that these neurons aren’t firing correctly. If we target that area and say, ‘We are going to nudge that area back to, say, 11 hertz,’ some of those symptoms may improve,” says Won. “In the converse scenario, in the right occipital parietal lobe where, if you’ve taken a hit, you may be cycling too fast. Let’s say it’s 30 hertz. You’re taking in too much information, oversampling your environment. And if you’re only able to process it using executive function 11 times per second, that information overload might manifest as anxiety.”

If the theory behind MeRT is true, it could explain, at least partially, why a person may suffer from many mental-health symptoms: anxiety, depression, attention deficits, etc. The pharmaceutical industry treats them with separate drugs, but they all may have a similar cause, and thus be treatable with one treatment. That, anyway, is what Won’s preliminary results are suggesting.

“You don’t see these type of outcomes with psychopharma or these other types of modalities, so it was pretty exciting,” he said.

There are lots of transcranial direct stimulation therapies out there, with few results to boast of. What distinguishes MeRT from other attempts to treat mental disorders with electrical fields is the use of EEG as a guide.

She’s convinced she’s having more impact on each individual

Sunday, December 30th, 2018

Mainstream medicine doesn’t have a great track record:

After 12 years of practicing family medicine in Wellesley, Massachusetts, Ronda Rockett was losing faith in her ability to help the majority of her patients.

Patient after patient would stream into her clinic with diabetes, weight problems, and heart disease. Rockett followed the medical guidelines, recommending healthier diets and more exercise. But despite her best efforts — even texting and emailing motivational follow-ups — many failed to change at all, either because they didn’t want to or didn’t have the means.

In 2013, eager to try something new, Rockett decided to quit medicine and close up her practice. What she did next, she says, is the most meaningful contribution to health care she’s made to date. She opened a CrossFit gym.

CrossFit is a high-intensity interval training and resistance exercise routine known for instilling a cult-like devotion among followers and promoting the low-carb diet. By the time Rockett opened a gym, she was already a devotee. Now age 51, she can do 32 pullups and deadlift 240 pounds. She attributes her fitness and lowered cholesterol to the program. And she believes she can help people make more substantive changes in their lives through CrossFit than she ever could practicing medicine.

“It’s exciting that I can treat and cure medical problems in the gym,” she said. “Just in the last week alone, I’ve gotten three different texts from people saying, ‘I don’t think you understand how much this has changed my life.’” Though she had 2,000 regular patients at her clinic and now works with just 70 regulars at her gym, she’s convinced she’s having more impact on each individual. Plus, she said, “This is more fulfilling.”

One continuous “Antarctica Ultramarathon” push to the finish line

Thursday, December 27th, 2018

When I listened to the audiobook version of Endurance, I thought it definitely qualified as a “harrowing” tale. British explorer Ernest Shackleton’s 1914 attempt to reach the South Pole did not go well, but modern endurance athlete Colin O’Brady‘s recent attempt to cross Antarctica, solo and unaided, has gone well:

Day 54: FINISH LINE!!! I did it! The Impossible First. 32 hours and 30 minutes after leaving my last camp early Christmas morning, I covered the remaining ~80 miles in one continuous “Antarctica Ultramarathon” push to the finish line. The wooden post in the background of this picture marks the edge of the Ross Ice Shelf, where Antarctica’s land mass ends and the sea ice begins. As I pulled my sled over this invisible line, I accomplished my goal: to become the first person in history to traverse the continent of Antarctica coast to coast solo, unsupported and unaided. While the last 32 hours were some of the most challenging hours of my life, they have quite honestly been some of the best moments I have ever experienced. I was locked in a deep flow state the entire time, equally focused on the end goal, while allowing my mind to recount the profound lessons of this journey. I’m delirious writing this as I haven’t slept yet.

Colin O'Brady in Antarctica

There is so much to process and integrate and there will be many more posts to acknowledge the incredible group of people who supported this project. But for now, I want to simply recognize my #1 who I, of course, called immediately upon finishing. I burst into tears making this call. I was never alone out there. @jennabesaw you walked every step with me and guided me with your courage and strength. WE DID IT!! We turned our dream into reality and proved that The Impossible First is indeed possible. “It always seems impossible until it’s done.” – Nelson Mandela.
#TheImpossibleFirst #BePossible

Should we be encouraging this?

Saturday, December 8th, 2018

I’m beginning to think men’s gymnastics should revolve athletes daring each other to do ever-crazier stunts:

Any idiot can train himself into the ground

Sunday, October 28th, 2018

Performance psychologist Dr. Noa Kageyama discusses the importance of mentally disengaging from work and practice:

A group of German and US researchers conducted a study of 109 individuals. The setup was pretty simple, consisting of two surveys, spaced 4 weeks apart to see how participants’ mental and emotional states might change over time.

The researchers were primarily interested in the relationship between psychological detachment (our ability to disengage from work during our “off” hours — a key factor in greater well-being and performance), exhaustion (feeling fatigued, emotionally drained/overwhelmed, and unable to meet the demands of our work), time pressure, and pleasurable leisure activities (the degree to which we engage in activities that recharge our batteries and balance out our work demands).

There were a couple interesting findings that came out of the resulting data.

Exhaustion begets exhaustion

You would think that emotionally exhausted folks would be more detached and disengaged from work in their off-work hours. Paradoxically, the opposite seems to be true.

The data suggest that individuals who were exhausted had an increasingly difficult time disconnecting from work concerns as the weeks went by. The idea being, when we’re exhausted, we tend not to do our best work, which makes us feel less capable of meeting the demands of the situation, which makes us worry more and expend even more energy, effort, and time trying to make up for our sub-par work, which only keeps the cycle of worry/practice/exhaustion going.

To use a music example, when we have a big audition coming up, there’s a tendency to worry more about our level of preparation, which leads us to practice more, worry more, and obsess more, which in turn makes it harder to disengage, take a break, and recoup our energy outside of the practice room, so we can dive back in refreshed, recharged, and ready to do our most productive and focused work.

Indeed, someone recently suggested to me that while our instinct when behind in our work is to put in a few extra hours at the office after work to catch up, what ends up happening is that we get home late, feel even more tired and drained, get less rest and relaxation, and return to work tired yet again to repeat the cycle. Instead, she suggested that it’s more productive to go home early, get quality R&R, and go to work early the next morning, fresher, more productive, and more motivated to get things done.

Time pressure makes things worse

The other finding was that time pressure seems to make detaching from work more difficult if you’re already feeling exhausted. As in, exhausted folks find it increasingly difficult to mentally detach from work and get the mental/physical break they need when they feel like they’re on a time crunch.

This makes sense too, as the less time we have to prepare, and the closer we get to the day of a big audition, the more likely we are to worry, stress, and obsess about it, even when we’re not practicing.

[...]

As Olympic marathoner Keith Brantly once said, “Any idiot can train himself into the ground; the trick is working in training to get gradually stronger.”

More false positives among the hypochondriac set

Thursday, September 13th, 2018

The new ECG Apple Watch could do more harm than good:

“Do you wind up catching a few undiagnosed cases? Sure. But for the vast majority of people it will have either no impact or possibly a negative impact by causing anxiety or unnecessary treatment,” says cardiologist Theodore Abraham, director of the UCSF Echocardiography Laboratory. The more democratized you make something like ECG, he says, the more you increase the rate of false positives — especially among the hypochondriac set. “In the case of people who are very type-A, obsessed with their health, and fitness compulsive, you could see a lot of them overusing Apple’s tech to self-diagnose and have themselves checked out unnecessarily.”

The cases in which Apple’s new watch could be most helpful are obvious: People with atrial fibrillation, family histories of heart disease, heart palpitations, chest pain, shortness of breath, and so on. Sometimes, Abraham says, patients come in with vague cardiovascular symptoms that they can’t reproduce during their visit. Folks like that, he says, often require more expensive, prescription-based monitoring systems. If a doctor could ask that kind of patient to record their symptoms on a gadget they already own, that could be a win for the healthcare provider and the patient.

As for everyone else, it’s hard to say what benefit Apple Watch’s on-demand ECG could have, and existing evidence suggests it might actually do more harm than good.

There is, however, the matter of life-saving potential to consider, which AHA president Ivor Benjamin mentioned not once but twice in his presentation at yesterday’s Apple Event. If there’s a silver lining to putting electrocardiograms on every Apple Watch wearer’s wrist, it’s that their data (if they choose to share it — Apple emphasized at the event that your data is yours to do with as you please) could help researchers resolve the uncertainty surrounding ECG screening in seemingly healthy people. Apple’s new wearable might not be the handy heart-health tool it’s advertised as, but it could, with your permission, make you a research subject.

Fitbit heart data reveals its secrets

Monday, September 3rd, 2018

Fitbit has now logged 150 billion hours’ worth of heart-rate data from tens of millions of people, all over the world:

Fitbit Heart Data 1 Resting Heart Rate by Age

Fitbit Heart Data 2 BMI vs. HR by Gender

Fitbit Heart Data 3 Resting Heart Rate with Exercise

Fitbit Heart Data 4 Activity Effect on Resting Heart Rate by Age

Fitbit Heart Data 5 Resting Heart Rate with Sleep

Fitbit Heart Data 6 Activity vs. Heart Rate by Country

From senescence to apoptosis

Tuesday, July 24th, 2018

Cells pick up damage all the time:

If the damage is sufficiently critical, the cell will respond by committing an orderly sort of suicide called apoptosis, which keeps it from causing any further problems. For lesser damage, there’s a less drastic alternative called senescence, in which the cell remains active and contributes its normal functions to the organism’s health, but it commits to no longer dividing. Over time, as animals age, more and more cells enter senescence, a process that’s thought to contribute to aging.

But it has gradually become apparent that senescent cells don’t just continue performing their normal function. They also produce a set of senescence-specific signaling molecules that can influence cells elsewhere in the body, including some that can trigger inflammation. The new work is based on the hypothesis that these signaling molecules might contribute to the changes that are associated with aging.

To test this, a large team of researchers did a relatively straightforward experiment: take senescent cells and implant them in an otherwise young and healthy mouse.

The authors chose fat cells, which typically don’t trigger an immune response when transplanted to a new animal. To get lots of senescent cells, they induced DNA damage, using either a drug or radiation (both produced similar results). While it would have been more relevant to obtain senescent cells from an older mouse, this allowed them to obtain lots of the cells they needed to do the experiments.

At various times after the transplant, the team measured a series of physical traits that change with age: average walking speed, muscle strength, endurance on a treadmill, time spent active, food intake and body weight. And while some of these didn’t change after the senescent cells were transplanted in, the young mice had clearly lost some strength by a month after the transplant: walking speed, endurance, and grip strength were all down significantly.

This change comes despite the fact that only about one in 10,000 cells in the body were senescent, transplanted cells. Obviously, this suggests that the cells are having an effect by talking to all the healthy ones around them. In fact, the researchers found that the transplanted cells’ presence seemed to cause some of the young animal’s cells to become senescent, amplifying their effect. Other experiments showed that the transplanted cells had stronger effects if the recipient was older or eating a high-fat diet.

For older mice receiving transplanted cells, one of the consequences was an increased chance of death. Risk of mortality was up by 5.2 fold, and there was no single cause of death or pathology that was increased by a similar amount. Instead, the animals just seemed to be less healthy.

At this point, the researchers shift focus to what they call a “senolytic agent.” That bit of jargon refers to a combination of two chemicals that cause senescent cells to die, possibly by shifting them from the senescence response over into the cell death response. The chemicals in question are quercetin, something found in a huge variety of plants (anyone who eats any vegetables undoubtedly ingests some of this every day). The second is called dasatinib, and you’re very unlikely to come across this as part of your diet, since it’s normally used as chemotherapy.

The combo of the two chemicals did what you’d expect. If they were administered immediately after the senescent cells were transplanted, the chemicals helped limit the cells’ impact on strength and endurance. For mice that were simply aging normally, the two chemicals also helped limit the loss of strength and endurance, and increased the animals’ daily activity relative to controls. In addition, the chemicals increased the average lifespan by 36 percent.

Why not carry ammunition cans?

Wednesday, July 18th, 2018

The US Army is moving away from the current Army Physical Fitness Test (APFT) to the new and improved Army Combat Readiness Test (ACRT):

This new six-event test will keep the two-mile run from the current Army Physical Fitness Test (APFT), but scraps the push-ups and sit-ups in favor of leg tucks, a medicine ball power throw, three-rep max dead lift, “T” push-ups, and a shuttle sprint-drag-carry.

[...]

The ACRT, for example, is comparatively much more time intensive than the APFT. Each set of equipment allows approximately five soldiers to complete the full six-event ACRT in seventy-five minutes. In an infantry battalion with ten sets of equipment and eight hundred soldiers, completing the ACRT will take sixteen days — three work weeks — if limited to normal morning PT hours. Since the current APFT throughput is only limited by the number of available graders, an entire battalion can easily complete the APFT in a single PT session. While there are ways a battalion could adjust to make executing the ACRT more efficient, the financial cost is more significant.

Beyond consuming more time, the ACRT transition is going to be expensive. A battalion’s set of equipment, or ten ACRT sets, is estimated at $12,000. With hundreds of battalions across the Army — combined with geographically dispersed units like the more than 1,100 ROTC campus locations, 1,600 recruiting stations, or US Army personnel stationed in embassies worldwide that need their own sets — startup costs for the ACRT could easily reach into the tens of millions of dollars, if not higher. That’s a big budget pill to swallow after almost four decades of a nearly cost-free physical fitness assessment. That also doesn’t address associated costs of equipment replacement over time, or potentially reconfiguring on-base fitness facilities to allow soldiers to train for these news tasks.

While the ACRT has been sold as a means to reduce soldier injuries, the new test introduces physical tasks that require proper training and monitoring, such as the dead lift and medicine ball power throw. According to the Army Public Health Center, musculoskeletal injuries account for 70 percent of all medically non-deployable personnel, and weight-bearing and exercise-related activities account for roughly 50 percent of all non-combat injuries. Many of those injuries result from overtraining and improper exercise.

[...]

Several ACRT tasks tie directly to physical requirements in combat — this is arguably its biggest advantage over the APFT. The shuttle sprint-drag-carry in particular includes a weighted sled pull that resembles evacuating a casualty, and the kettle bell carry simulates moving with ammunition cans. To save money and even better replicate combat conditions, the Army could replace ACRT-specific equipment with items readily available in the force.

Rather than purchasing kettle bells to simulate carrying ammunition, why not carry ammunition cans? Rather than selling all of the huge number of ammunition cans the Army goes through to the public (a very common practice), it would be easy to fill them with a set amount of weight and use them for the test. Also, rather than investing in a new type of sled to pull around a couple 45-pound plates, why not use the standard-issue SKEDCO litter system? Standardizing the weight is simple, and using the SKEDCO would reinforce an actual tactical task.

The physical strength of nations varies considerably

Tuesday, July 17th, 2018

I was watching the latest CrossFit documentary on Netflix, The Redeemed and the Dominant, and this reminded me of Anatoly Karlin’s piece on the (physical) strength of nations, which looks at the stereotype that Northerners are stronger than Southerners:

The average Germanic seems to be around 15 years “younger” than the average Italian or Spaniard in terms of hand grip strength. These are remarkably big differences, around 1 S.D.’s worth. Average German, Swede, or Pole might have a 15 SQ (strength quotient) advantage over the average South European.

For context, there is a ~2.5 S.D. difference in male and female grip strength.

Women have around 60% of the hand grip strength of men. Huge difference… but remarkably, seems to be about equal to the difference between developed Anglo-German/Slavic Europe and the Indian subcontinent!

Why do so many of these studies focus on grip strength? Because it is easy to measure, changes the least as people age (hand grip is the last to go), and is exercised more or less universally.

My best guess is that in terms of S.D.’s it goes something like this in terms of hand grip strength (Flynn! denotes members of those ethnicities that dwell in First World environments).

  • +1 Icelanders
  • +0.5 Steppe!East Asians (i.e.Mongols)
  • 0 Balto-Slavic-Germanics, Flynn!WestAfricans
  • -.5 East Asians
  • -1 Mediterraneans, Flynn!Indians, WestAfricans
  • -2 Indians

Icelanders, with a mere 300,000 people, dominate the world strongman competitions. They have won 9 Gold medals, more than any other country other than the US, which has won 11 (and has ONE THOUSAND times its population).

Icelandic women have also won four years of the past decade’s worth the Crossfit Games.

Athletes were quite ready to take the bargain

Sunday, July 15th, 2018

There’s a well-known survey in sports, known as the Goldman Dilemma:

For it, a researcher, Bob Goldman, began asking elite athletes in the 1980s whether they would take a drug that guaranteed them a gold medal but would also kill them within five years. More than half of the athletes said yes. When he repeated the survey biannually for the next decade, the results were always the same. About half of the athletes were quite ready to take the bargain.

Only recently did researchers get around to asking nonathletes the same question. In results published online in February, 2009 in the British Journal of Sports Medicine, exactly 2 of the 250 people surveyed in Sydney, Australia, said that they would take a drug that would ensure both success and an early death. “We were surprised,” James Connor, Ph.D., a lecturer at the University of New South Wales and one of the study’s authors, said in an e-mail message. “I expected 10-20 percent yes.” His conclusion, unassailable if inexplicable, is that “elite athletes are different from the general population, especially on desire to win.”

(Hat tip to @TweetWivMe.)

Marine experiment finds women get injured more frequently, shoot less accurately than men

Thursday, July 5th, 2018

The Marine Corps recently finished a nine-month long experiment at both Camp Lejeune, North Carolina, and Twentynine Palms, California, to assess how female service members perform in combat:

It found that all-male squads, teams and crews demonstrated better performance on 93 of 134 tasks evaluated (69 percent) than units with women in them. Units comprising all men also were faster than units with women while completing tactical movements in combat situations, especially in units with large “crew-served” weapons like heavy machine guns and mortars, the study found.

Infantry squads comprising men only also had better accuracy than squads with women in them, with “a notable difference between genders for every individual weapons system” used by infantry rifleman units. They include the M4 carbine, the M27 infantry automatic rifle (IAR) and the M203, a single-shot grenade launcher mounted to rifles, the study found.

The research also found that male Marines who have not received infantry training were still more accurate using firearms than women who have. And in removing wounded troops from the battlefield, there “were notable differences in execution times between all-male and gender-integrated groups,” with the exception being when a single person — ”most often a male Marine” — carried someone away, the study found.

Female USMC Mortarman

The gender-integrated unit’s assessment also found that 40.5 percent of women participating suffered some form of musculoskeletal injury, while 18.8 percent of men did. Twenty-one women lost time in the unit due to injuries, 19 of whom suffered injuries to their lower extremities. Of those, 16 women were injured while while carrying heavy loads in an organized movement, like a march, the study found.

(This is old news, but I stumbled across it again.)

Meet the peewee powerlifters

Thursday, May 10th, 2018

The New York Times invites us to meet the peewee powerlifters who are changing the demographics of the sport:

For the past seven months, Etta has been fully engaged in the sport of powerlifting and has just set 12 new American records. She is 11 years old and weighs 65 pounds.

“I don’t just like power lifting; I love it,” she said. “It makes me feel strong, and like I can do anything.”

Damiyah Smith, also 11, and from Commerce, Okla., began powerlifting in fourth grade and goes by the nickname “The Powerhouse Princess.” She’s become a staple on the youth circuit, earning 22 world records over the course of two years and starting her own fitness brand for children, Powerhouse Athletics.

[...]

And Luma Valones, who is just 5, has been performing weighted dead lifts, squats and bench presses since she was 3. Luma, who is in kindergarten, has her own private Instagram page, “HappyLuma,” where her mother, Nicole Lacanglacang, 36, a graphic designer who lives in Hayward, Calif., shares videos of her triumphantly raising a set of pink weights over her chest. Ms. Lacanglacang, a powerlifter herself, began training her daughter on a homemade PVC pipe barbell sporting 3.5 pounds out of her garage in February 2016. Luma’s dead lift maximum is now 53 pounds, 18 more than her total body weight.

Ms. Lacanglacang said powerlifting has made her daughter self-confident and is helping her to foster a positive body image. “She tells me she wants to get bigger, that she doesn’t want skinny arms — just big muscles,” she said. Luma seconds that, exuberantly declaring that she wants “to be the strongest person in the universe.”

[...]

Priscilla Ribic, the executive director and chair of the woman’s committee for USAPL, said that powerlifting has proved particularly popular among girls; the 2018 USA Powerlifting Nationals competition was over 75 percent female, she said. “I have never seen females outnumber the males, so it was really kind of awesome,” Ms. Ribic said.

Nonelite males routinely outperform the best elite females

Wednesday, May 2nd, 2018

A female Duke Law School professor who competed in track and field internationally in the 1980s discusses the International Association of Athletics Federations’ new rules limiting entry into women’s events to athletes who have testosterone levels that are capable of being produced solely by ovaries:

Understanding the rules and why they make sense is hard. They are based in biology people don’t know or don’t like to talk about and, let’s be honest, at least in some circles, they’re politically incorrect. They force us to talk about women’s bodies when it is increasingly taboo to do so, and they run counter to the movement that seeks to include transgender and intersex people in social institutions based on their gender identity rather than their biology.

She’s writing in the New York Times, in case you couldn’t tell:

Advocates for intersex athletes like to say that sex doesn’t divide neatly. This may be true in gender studies departments, but at least for competitive sports purposes, they are simply wrong. Sex in this context is easy to define and the lines are cleanly drawn: You either have testes and testosterone in the male range or you don’t. As the I.A.A.F.’s rules provide, a simple testosterone test establishes this fact one way or the other.

Testosterone throughout the life cycle, including puberty, is the reason the best elite females are not competitive in competition against elite males. This 10- to 12-percent sex-based performance gap is well documented by sports and exercise scientists alike. But it isn’t the most important performance gap. Rather, that’s the mundane fact that many nonelite males routinely outperform the best elite females.

Each year, the world’s best time in the women’s marathon is surpassed by hundreds of men. The women’s world records in all of the races on the track from 100 meters to 10,000 meters are also surpassed by many men each year, including by many high school boys. For example, in 2017, 36 boys ran faster than Florence Griffith Joyner’s seemingly unassailable 100-meter record of 10.49.

There is no characteristic that matters more than testes and testosterone. Pick your body part, your geography, and your socioeconomic status and do your comparative homework. Starting in puberty there will always be boys who can beat the best girls and men who can beat the best women.

Because of this, without a women’s category based on sex, or at least these sex-linked traits, girls and women would not have the chance they have now to develop their athletic talents and reap the many benefits of participating and winning in sports and competition. Eric Vilain, a geneticist who specializes in differences of sex development, has been blunt about it: removing sex from the eligibility rules would “be a disaster for women’s sport … a sad end to what feminists have wanted for so long.”

This may sound like hyperbole but it isn’t. In competitive sport, winning and room at the top are what ultimately matter, so relative numbers are irrelevant. It doesn’t matter that there are 100 females and three males in a girls’ race if the three males win spots in the final or on the podium because they are males. The unusually high incidence of intersex athletes in the women’s middle distances and their reported 100 percent win share in the women’s 800 meters at the Olympic Games in Rio show their disproportionate power.

Try several sports before specializing

Sunday, March 11th, 2018

The logic of early specialization is straightforward:

Training is necessary to develop skill, but there is a limit to how much a person can train, not just because there are only 24 hours in a day, but because training is physically and psychologically exhausting. A person can train intensively for only a few hours a day without injuring themselves or getting burned out. Thus, the child who starts training early will have a virtually insurmountable training advantage over the child who starts later. Training is, of course, necessary to develop skill. However, the findings of a study recently published in the Journal of Sports Sciences show that later specialization may actually lead to better performance in the long-term.

Professor Arne Güllich, director of the Institute of Applied Sport Science at the University of Kaiserslautern in Germany, compared the training histories of 83 athletes who medaled in the Olympics, or a World Championship event, to those of 83 athletes who competed at that level but did not medal. (The groups were matched on age, gender, and sport to control for any influence of these factors on the results. For every medalist in a given event, the sample included a non-medalist in that event of the same gender and roughly the same age.) The results showed that both the medalists and non-medalists started practicing in their main sport before the age of 12. However, the medalists started training in their main sport an average of 18 months later than the non-medalists. (The medalists started at age 11.8, on average, compared to age 10.3 for the non-medalists.) The medalists also accumulated significantly less training in their sport during adolescence and significantly more training in other sports. This pattern of results held across a wide range of sports, from skiing to basketball to archery.

Along with reducing the risk of burnout and injury, allowing children to sample a range of activities before specializing allows a process known as gene-environment correlation to operate to its full extent. This is the idea that our genetically-influenced traits have an influence on the environments that we seek out and create for ourselves. As recently argued by the behavioral geneticist Elliot Tucker-Drob, gene-environment correlation is fundamental to understanding how expertise develops in children. For example, given the opportunity to try several sports, a child may discover that she has a high level of physical endurance and gravitate towards soccer because it places a premium on this attribute. She may also prefer soccer over other sports because she is extroverted and enjoys having teammates. In turn, after some initial success in the sport, the child’s coach may encourage her to continue playing soccer, setting in motion a “virtuous cycle” of effort followed by improvement, followed by further effort and improvement. However, this natural selection process will never unfold if the child isn’t given ample opportunity to try several sports before specializing.