How Exercise May Help the Memory Grow Stronger

How Exercise May Help the Memory Grow Stronger

Exercise may help the brain to build durable memories, through good times and bad.

Stress and adversity weaken the brain’s ability to learn and retain information, earlier research has found. But according to a remarkable new neurological study in mice, regular exercise can counteract those effects by bolstering communication between brain cells.

Memory has long been considered a biological enigma, a medley of mental ephemera that has some basis in material existence. Memories are coded into brain cells in the hippocampus, the brain’s memory center. If our memories were not written into those cells, they would not be available for later, long-term recall, and every brain would be like that of Dory, the memory-challenged fish in “Finding Nemo.”

But representations of experience are extremely complex, and aspects of most memories must be spread across multiple brain cells, neuroscientists have determined.

These cells must be able to connect with one another, so that the memory, as a whole, stays intact.

The connections between neurons, known as synapses, are composed of electrical and chemical signals that move from cell to cell, like notes passed in class. The signals can be relatively weak and sporadic or flow with vigor and frequency. In general, the stronger the messages between neurons, the sturdier and more permanent the memories they hold.

Neuroscientists have known for some time that the potency of our synapses depends to some degree on how we live our lives. Lack of sleep, alcohol, diet and other aspects of our lifestyles, especially stress, may dampen the flow of messages between brain cells, while practice fortifies it. Repeat an action and the signals between the cells maintaining the memory of that action can strengthen. That is learning.

There also have been hints that exercise might affect synapses in the hippocampus. Exercise has been shown in many studies to improve learning and memory. But only a few past animal studies have closely tracked changes to synapses after exercise and none looked simultaneously at stress, leaving the results unrepresentative of actual life, which always contains some amount of stress.

So, for the new study, which was published this month in Neurobiology of Learning and Memory, researchers at Brigham Young University in Provo, Utah, gathered healthy, male mice. (They plan similar future studies with female mice.)

They divided the animals into groups. Some, as a control, continued with their normal rodent lives. Others began running at will on wheels in their cages; mice seem to enjoy running and these eagerly covered about three miles a day.

After a month, some of the sedentary animals were exposed to three days of stressful experiences. These mostly involved some type of mild restraint, which makes prey animals like mice understandably anxious.

The researchers were trying to simulate relatively chronic stress with the animals, somewhat like what most of us might feel with ongoing work pressures or other anxieties.

Some of the runners were also restrained and stressed.

Then, to see if any changes to the animals’ synapses would be reflected in their lived experience, the researchers had some mice from each group learn a maze with a treat in one hidden corner.

Finally, the researchers looked microscopically at the operations of the synapses joining the neurons in the animals’ hippocampi. By electrically stimulating some of the isolated cells, they could see how many and what types of messages jumped between them.

It was immediately clear that three days of chronic stress had reduced the effectiveness of the synapses in the stressed-out, sedentary animals, compared to those from the control mice. Their intracellular connections were much weaker.

The unstressed runners, on the other hand, now had the strongest, busiest synapses, suggesting that their ability to learn and remember would be higher than in the other animals.

Perhaps most interesting, the animals that had run and also experienced chronic stress had synapses that resembled those from the normal, unstressed control group. They were not as strong as those from the never-stressed runners but much stronger than those from the animals that had been stressed but not exercised.

Behaviorally, the runners, stressed or not, also learned the location of the treats in the maze more quickly than the sedentary animals did, and remembered it more rapidly and accurately several weeks later.

Over all, it seems that exercise had improved the animals’ memories, even in the face of stress, by bulking up their synapses and buffering the negative effects that stress otherwise would have had on those neural connections, says Roxanne Miller, who led the study as part of her doctoral research at B.Y.U.

It is not yet clear, though, she says, how exercise changed the animals’ synapses at a molecular level. She and her colleagues did find increases in the activity of certain genes and the levels of some proteins in the brains of the runners that could have contributed to the changes in their synapses, she says.

But far more research is needed into that issue, as well as into whether other forms of exercise, such as resistance training or gentle walking, would have comparable effects, she says.

And of course, mice are not people, and it is impossible to know if the same changes occur in our synapses when we exercise.

But even so, the results do seem to offer one more reason being physically active “is a very good idea,” Dr. Miller says.

Modern Primers for Naturally Glowing Skin

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Modern Primers for Naturally Glowing Skin

Going makeup-free can be a liberating concept until you’re confronted with bad lighting, skin flare-ups or bouts of redness. In those times, getting by on moisturizer alone can be a challenge. Fortunately, a new breed of hybrid beauty product has emerged to subtly minimize imperfections without requiring layers of foundation or heavy powders.

Behold the modern primer. Of course, these fluids have been around for decades, employed as a first step to even out skin tone, fill in pores and smooth the surface of your face to prep it for foundation. But the formulas of the past were light on any lasting benefits, and often left a white-ish cast on the complexion.

The latest iterations, however, have smart technology — soft-focus filters, breathable textures — and skin-care-level ingredients, making them function as highlighter, serum and moisturizer in one tube. In fact, you might find that they flatter your complexion well enough that you can wear them alone — as a base, in lieu of makeup — and not regret that decision later.

“The new formulas have skin-enhancing qualities, so they give you the most natural of glows,” says New York City-based makeup artist Hannah Murray, who is partial to Dr. Barbara Sturm’s Glow Drops($145), a milky lotion that contains active natural ingredients (including anti-inflammatory purslane) and mineral pigments to illuminate and hydrate dull skin. Tatcha’s The Silk Canvas ($52) is inspired by the traditional geisha ritual of pressing melted bintsuke(Japanese wax) over the face to protect it from makeup; this modern spin utilizes botanicals to fend off the damaging effects of pollution. Charlotte Tilbury’s Brightening Youth Glow ($55), meanwhile, pairs trendy wellness ingredients, like revitalizing chlorella and nourishing vitamin B, with high-tech pearlized particles for a creamy gel that “instantly blurs, evens imperfections and corrects redness,” Tilbury explains. When worn on its own, she finds, the primer gives skin a “gorgeous” effect.

Rather than quick fixes, many of today’s primers are formulated with long-term anti-aging in mind (and have price tags that rival those of expensive creams). La Prairie’s Cellular Radiance Perfecting Fluide Pure Gold ($550), for example, pairs collagen-boosting peptides with finely milled flecks of gold to scatter light across the face while also firming it over time. Or consider Sisley-Paris’s Instant Éclat ($90): Its plant extracts replenish skin’s natural “water cushion” for a plumped result that lasts after the soft-pink lotion has melted into your skin.

Still, if dryness is an issue, it’s best to apply these primers over traditional moisturizers. Murray often works them in with a mini-massage technique. “I like to apply with my fingers, smoothing from the center of the face outward and then patting in with the palms of my hands,” she says, adding that this helps “stimulate blood flow and plump the skin.” Will you still need a touch of concealer to cover up under-eye circles or a blemish? Perhaps, but you will need far less. And that can translate into a more realistic radiance. As Murray says, it’s always better to take “a light hand when it comes to the skin.”

This article was originally published in The New York Times.  Read the original article.

Going for the Gaunt: How Low Can an Athlete’s Body Fat Go?

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Going for the Gaunt: How Low Can an Athlete's Body Fat Go?

Having won six medals in his career, Seattle-based speed skater Apolo Ohno stands to make U.S. Winter Olympic history if he wins another one in upcoming short-track competition—the 1,000-meter race this weekend or the 5,000-meter relay on February 26. In various reports, Ohno has said that he’s in the best physical shape of his life, weighing five kilograms less than he did for the 2006 Games in Torino, Italy, and nine kilograms less than he did for the 2002 Salt Lake City Olympics. Ohno is now 65 kilograms of almost pure muscle: only 2.8 percent of his body consists of fat.

Elite athletes, of course, are expected to be slimmer than the rest of us. The average amount of body fat in the U.S. is 22 percent for men and 32 percent for women, although most experts believe a healthier body-fat content is 15 percent for men and 22 percent for women, according to The Ultimate Fit or Fat, a book by nutritionist Covert Bailey. Ohno’s fat level, though, is down there even for an athlete.

So how low is too low? After all, fat is crucial for normal physiology—it helps support the skin and keep it lubricated, cushions feet, sheaths neurons, stores vitamins, and is a building block of hormones.

Marina Mourtzakis, an assistant professor at the University of Waterloo in Ontario who specializes in nutrition, exercise and metabolism, gives ScientificAmerican.com the skinny on athletes’ fat.

How do athletes achieve such lean physiques?

It takes a long time to achieve and maintain these low levels of body fat. It really comes down to balance. Energy in equals energy out. With increased energy expenditure and lower caloric intake, you can tip the scale to reduce weight.

Is it safe for them to get down to 2 percent body fat?

Athletes have to take in adequate amounts of protein to maintain muscle mass, and they still have to take in adequate amounts of carbohydrate to maintain optimal training intensities. If they do this properly, they can maintain heavy workout sessions and lose fat without compromising their performance.

So 2 percent would be a safe lower limit if athletes eat right. What sort of diet should they have?

Meat, fish, poultry and dairy are good protein sources. But they also need to take in a fair amount of carbohydrates. When you’re training at high intensities, you’re burning more carbs. When those stores deplete, your body has to use something else—this could be fat, but it could be protein. People don’t always appreciate how difficult it is to lose fat without losing protein. For athletes to maintain a high level of performance and low body fat, it means they have to a have a really good balance in their diet in order to maintain their health.

Should athletes continuously strive to lose body fat?

Athletes should not be “dieting” three to four months prior to a major competition. They should be weight stable by the time the competition date arrives. Any changes in weight, if an athlete has that as a goal, would happen much earlier in training to avoid problems with performance and potential injury.

Is it physically desirable to be below normal body fat levels?

It really depends on the sport an athlete is involved with. For example, snowboarders probably have a normal amount of fat, whereas long-distance and endurance athletes [like speed skaters, cross-country skiers and biathletes] likely have less.

Several techniques can estimate body fat composition: Skin-fold measurements; bioelectric impedance tests, which use a small electrical current to estimate the amount of water in the body and then extrapolate a fat figure; and tests based on displacement of water (hydrodensitometry) or air (the “Bod Pod”). How good are they?

They’re not very accurate. Dual-energy x-ray absorptiometry [DXA—the same technology used to measure bone mineral density], magnetic resonance imaging and computed tomography are highly precise—[each] can measure fat to within 2 percent accuracy. DXA is probably most common in research, because MRI and CT [which can also determine body composition] are so expensive and inaccessible.

 

 

This article was originally published in Scientific American. Read the original article.

A Before-School Exercise Program May Help Children Thrive

A Before-School Exercise Program May Help Children Thrive

A supervised exercise program that gets young children running and playing for an hour before school could make them happier and healthier, while also jibing with the needs and schedules of parents and school officials, according to a new study involving two dozen elementary and middle schools.

The results also caution, however, that the benefits may depend on how often children actually participate.

Physical activity among children in most of the developed world has been on a steep decline for decades. National exercise guidelines in the United States recommend that children and adolescents engage in at least an hour of exercise every day. But by most estimates, barely 20 percent of young people are that active, and many scarcely exercise at all. Meanwhile, rates of obesity among children as young as 2 hover at around 17 percent, according to the Centers for Disease Control and Prevention.

Understandably, many concerned experts have suggested a variety of physical-activity interventions, from more sports programs to the use of “active” video games that allow children to move without relinquishing their screens and joysticks.

But many of these initiatives are expensive, logistically complex, time consuming or otherwise impractical.

So in 2009, a group of mothers in Massachusetts organized a simple, before-school activity program in their local grade school. They opted for the before-school start because they hoped to add to the total amount of time their kids spent moving and not displace existing physical education classes or after-school sports. It also struck many of the working parents as convenient and, apparently, did not lead to bitter complaints from their children about early rising times.

The original one-hour sessions consisted of a warm-up, running, calisthenics and rousing group games like tag, led by parent volunteers. The workouts proved to be so popular that other parents began asking if they could start a similar program at their children’s schools

Today, the program has gained a formal curriculum, a name and acronym, Build Our Kids’ Success (BOKS), along with corporate underwriting from the shoe manufacturer Reebok. (The similarity of the nomenclature is intentional.) It also has become one of the world’s most widely disseminated, free, school-based exercise programs. According to a BOKS spokeswoman, it is used at more than 3,000 schools worldwide.

But popularity is no guarantee of efficacy. So researchers at Harvard University and Massachusetts General Hospital, some of whom have children enrolled in a BOKS program, began to wonder about the measurable impacts of the exercise.

They also were aware that a number of school districts in Massachusetts had plans to allow BOKS at their elementary and middle schools during the 2015 or 2016 school years and, for the new study, which was published this week in the American Journal of Preventive Medicine, asked if they could piggyback their research onto the start of those programs. Principals at 24 schools agreed. The schools included students from a broad spectrum of incomes.

The researchers then asked those families planning to participate in BOKS, which is always voluntary, if they and their children would join a study.

Several hundred students in kindergarten through eighth grade and their parents consented. Other children, who would not be joining the exercise program, agreed to serve as a control group.

The researchers measured everyone’s heights, weights, body mass indexes and, through brief psychological surveys, general happiness, vigor and other signs of well-being.

For 12 weeks, the students then played and ran during before-school exercise. At some schools, the program was offered three times a week, at others twice.

Afterward, the researchers returned and repeated the testing.

At this point, those students who had exercised before school three times per week had almost all improved their B.M.I.s and fewer qualified as obese. (Many had gained weight as children should while they are growing.) They also reported feeling deeper social connections to their friends and school and a greater happiness and satisfaction with life.

Those students who had exercised twice a week also said they felt happier and more energetic. But the researchers found no reductions in their body mass.

The students in the control group had the same B.M.I.s or higher and had no changes to their feelings of well-being.

The upshot is that a one-hour, before-school exercise program does seem likely to improve young people’s health and happiness, says Dr. Elsie Taveras, a professor at Harvard and head of general pediatrics at Massachusetts General Hospital, who oversaw the study and whose children have participated in BOKS. (The experiment was partially funded by the Reebok Foundation, as well as the National Institutes of Health and other sources. None of the funders had control of the design or results, Dr. Taveras says.)

But the benefits are most noticeable if children exercise “at least three times a week,” she says.

This study was short-term, though, and looked only at a few, narrow physical and emotional impacts. Dr. Taveras and her colleagues hope soon to track the program’s impacts, if any, on academics and on aerobic fitness.

Perhaps most important, the study was not randomized. It involved self-selected students and families who chose to join. The results, in theory, would apply only to the kinds of children who will get up early and run and hop and skip and squeal for an hour before school.

But, Dr. Taveras says, those should be all children.

“In my experience as a pediatrician and parent, kids naturally love to move,” she says. “They revel in it. We have socialized that love out of them.”

She believes that programs such as the one in this study might help to re-instill some of our children’s instinctual pleasure in motion, she says.

“I’ve watched” sessions, she says. “You can see the kids light up with joy.”

This article was originally published in The New York Times.  Read the original article.

Lift Weights, Eat More Protein, Especially if You’re Over 40

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Lift Weights, Eat More Protein, Especially if You’re Over 40

People who would like to become physically stronger should start with weight training and add protein to their diets, according to a comprehensive scientific review of research.

The review finds that eating more protein, well past the amounts currently recommended, can significantly augment the effects of lifting weights, especially for people past the age of 40. But there is an upper limit to the benefits of protein, the review cautions.

On the other hand, any form of protein is likely to be effective, it concludes, not merely high-protein shakes and supplements. Beef, chicken, yogurt and even protein from peas or quinoa could help us to build larger and stronger muscles.

It makes intuitive sense that protein in our diets should aid in bulking up muscles in our bodies, since muscles consist mostly of protein. When we lift weights, we stress the muscles and cause minute damage to muscle tissue, which then makes new proteins to heal. But muscles also will readily turn to and slurp up any bonus proteins floating around in the bloodstream.

Knowing this, bodybuilders have long swallowed large amounts of gloppy, protein-rich shakes after workouts in the expectation of adding greater bulk to their muscles than the lifting alone.

But the advantages of added dietary protein for the rest of us have been less clear. Past studies have indicated that, in general, people will gain more strength and muscle mass while weight training if they up their intake of protein than if they do not. But many of those studies have been relatively small or short-term and often have focused on only one kind of person, such as young men or older adults, or one kind of protein, such as whey shakes or soy.

Whether everyone, including women, benefits similarly from consuming added protein while weight training and just how much protein is ideal, as well as what that protein should consist of and when it should be eaten, are all open questions.

So for the review, which was published in the British Journal of Sports Medicine, researchers from McMaster University in Hamilton, Ontario, and other institutions decided to aggregate the results from the best past studies of weight training and protein.

Using databases of published research, they looked for experiments that had lasted at least six weeks, included a control group and carefully tracked participants’ protein intake as well as the eventual impacts on their muscle size and strength.

They wound up with 49 high-quality past experiments that had studied a total of 1,863 people, including men and women, young and old, and experienced weight trainers as well as novices. The sources of the protein in the different studies had varied, as had the amounts and the times of day when people had downed them.

To answer the simplest question of whether taking in more protein during weight training led to larger increases in muscle size and strength, the researchers added all of the results together.

And the answer was a resounding yes. Men and women who ate more protein while weight training did develop larger, stronger muscles than those who did not.

The impacts of this extra protein were not enormous. Almost everyone who started or continued weight training became stronger in these studies, whether they ate more protein or not.

But those who did ramp up their protein gained an extra 10 percent or so in strength and about 25 percent in muscle mass compared to the control groups.

The researchers also looked for the sweet spot for protein intake, which turned out to be about 1.6 grams of protein per kilogram of body weight per day. In practical terms, that would amount to about 130 grams of protein a day for a 175-pound man. (A chicken breast has about 45 grams of protein.)

Beyond that point, more protein did not result in more muscle benefits.

That number is considerably higher, however, than the protein levels called for in the current federal recommendations, which suggest about 56 grams of protein a day for men and 46 grams a day for women.

“We think that, for the purposes of maximizing muscular strength and mass with resistance training, most people need more protein” than is advised in the recommendations, says Rob Morton, a doctoral student at McMaster who led the study.

That advice holds especially true for middle-aged and older weight trainers, he says, almost none of whom were getting the ideal amount of protein in these studies and who, presumably in consequence, tended to show much smaller gains in strength and muscle size than younger people.

On the other hand and conveniently, any type of and time for protein was fine. The gains were similar if people downed their protein immediately after a workout or in the hours earlier or later, and it made no difference if the protein was solid or liquid, soy, beef, vegan or any other.

Still, many questions remain, including whether adding more protein affects body weight or metabolism and if so, what that means for health.

“We obviously need more studies,” Mr. Morton says.

But in the meantime, if you are wondering about your own protein intake, you can find many apps that will parse your diet, he says.

This article was originally published in The New York Times.  Read the original article.

OLYMPICS COULD REQUIRE ATHLETES’ GENETIC CODE TO TEST FOR DOPING

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OLYMPICS COULD REQUIRE ATHLETES' GENETIC CODE TO TEST FOR DOPING

FOR YEARS, THE World Anti-Doping Agency has considered requiring all Olympic athletes to submit copies of their genetic code. It would work as a check on so-called “gene doping,” the idea of changing the body’s biological machinery to make it stronger, run faster, or recover more quickly. A clean slate would reveal any nefarious performance-boosting tweaks—like, theoretically, altering the expression of fast-twitch muscle genes to engineer a perfect sprinter.

Establishing a genetic baseline for every professional athlete has long been cost-prohibitive—especially if it calls for a full genome sequence. But on Monday, February 5, the proposal is being seriously discussed for the first time today at WADA’s headquarters in Montreal. As the cost of sequencing a person’s entire genome drops to only a few hundred dollars, the agency could implement the plan within the next few years. “It will be easy in the future to have full genome sequencing for a reasonable amount of money,” said Olivier Rabin, WADA’s science director. “It will be reasonable to have full genome sequencing with some very strong ethical guidelines.”

Genetic sequencing would be an extension of an idea sports authorities developed in 2008, called the biological passport. It serves as a way of monitoring various indicators of an athlete’s blood, hormones, and body chemistry over time—looking for changes that could indicate cheating, even though the athlete may not have triggered a positive drug test. The passport looks for physiological changes caused by doping. And it has an eight-year statute of limitations so they can re-test older blood or urine samples when new tests or analytical methods are developed.

WADA authorities have already used the passport to catch athletes who use trace amounts of drugs that are below the testing threshold. But without a baseline read of an athlete’s genes, it would be harder to identify doping cases that modify the body’s blueprint itself. WADA has already banned gene doping—the practice of manipulating the genetic code to boost athletic performance—in anticipation of new forms of cheating, though no athletes have been charged so far. In 2006, a German track coach was suspected of using an anemia drug called Repoxygen to help turn on genes that control the production of blood oxygen levels. While he didn’t get busted for that offense, he was later convicted of giving performance-enhancing drugs to teen athletes.

Sports scientists who are advising WADA now are considering if the best way to prevent gene doping would be to have a record of the athlete’s entire genetic code—or possibly, just the sections that contain genes associated with athletic performance.

The problem is that genes often work in combination with each other in ways that aren’t completely understood, according to Thomas Friedmann, head of WADA’s gene doping advisory panel and a professor of pediatrics at the University of California San Diego. “The connection between a given gene and a given athletic ability is not one to one,” Friedmann says. “People have claimed that specific genes for fast-twitch muscle fibers or energy metabolism will influence athletic potential, and I think there’s probably some truth in those. But they are not specific determinants to whether they are a successful athlete or not.”

Gene-editing techniques such as Crispr/Cas-9 could theoretically be used to inhibit genes regulating myostatin, a growth factor that inhibits muscle development. Several young children have been reported with myostatin abnormalities, and have developed enormous muscles. And these same gene-editing techniques could be use to insert genes that regulate blood-oxygen levels, for example, which are critical for endurance athletes, or genes that regulate removal of lactic acid after a hard effort. But Friedmann, who runs a gene therapy lab at UCSD, is skeptical that genetically-enhanced super-athletes will be trotting around Olympic stadiums anytime soon.

“It’s very hard,” says Friedmann. “If you think about how hard it is to design and work through the technical and procedural issues for human gene therapy, that’s been very difficult. You can’t just go throwing around things in experimental procedures with humans. There are international constraints.”

That may be true for publicly-funded medical labs, but as long as sports have been around, some athletes have found private doctors willing to prescribe illegal drugs, experiment on themselves, or even try out new unproven techniques on athletes desperate to win. That kind of risk-taking likely won’t change if there’s a perceived advantage to altering genetic code to boost performance.

As the WADA panel discusses whether it makes sense to require genome sequences in whole or in part, they’ll also tackle issues of genetic privacy. If an athlete submits their sequence, the people who get to see that information will likely be debated by athletes, coaches and sports officials.

Kikkan Randall, a US Olympic cross-country skier who will be competing in PyeongChang this month, says she’d like to see the proposal first, but likes the idea of increased transparency. She’s competed against Russian skiers who have then later been busted for doping, and wants an even biological playing field.

“If that’s what it is going to take to keep the sport clean, I’d be in favor of it,” Randall said from her pre-Olympic training camp in Austria. And sequencing the genomes of athletes might have an unexpected benefit, she notes. Knowing more about the interplay of genetics, biology and training that makes high-level athletes perform could also help cure diseases and conditions faced by the rest of us.

 

 

This article was originally published in Wired. Read the original article.