Isegoria

Overweight? Standing May Be Solution:

Hamilton recruited a few laboratory rats and pigs, as well as about a dozen human volunteers, including himself, to learn more about the physiological effect of sitting. The lab animals laid the foundation for the research in two different experiments. The animals were injected with a small amount of fat that contained a radioactive tracer so the researchers could determine what happened to the fat.

“What’s the fate of that fat?” Hamilton asked during a telephone interview. “Is it burned up by the muscle?”

The radioactive tracer revealed that when the animals were sitting down, the fat did not remain in the blood vessels that pass through the muscles, where it could be burned. Instead, it was captured by the adipose tissue, a type of connective tissue where globules of fat are stored. That tissue is found around organs such as the kidneys, so it’s not really where you want to see the fat end up.

The researchers also took a close look at a fat-splitting enzyme, called lipase, that is critical to the body’s ability to break down fat.

After the animals remained seated for several hours, “the enzyme was suppressed down to 10 percent of normal,” Hamilton said. “It’s just virtually shut off.”

The results from the animal studies were very convincing, he said, and human experiments were just as compelling. The researchers injected a small needle into the muscles of the human volunteers and extracted a small sample for biopsy. Once again, the enzyme was suppressed while the humans remained seated. That resulted in retention of fat, and it also resulted in lower HDL, the “good cholesterol,” and an overall reduction in the metabolic rate.

Dr. Clinton T. Rubin, director of the Center for Biotechnology at the State University of New York at Stony Brook, has found that a Low Buzz May Give Mice Better Bones and Less Fat:

All he does is put mice on a platform that buzzes at such a low frequency that some people cannot even feel it. The mice stand there for 15 minutes a day, five days a week. Afterward, they have 27 percent less fat than mice that did not stand on the platform — and correspondingly more bone.

Some background:

The story of the finding, which was published online and will appear in the Nov. 6 issue of Proceedings of the National Academy of Sciences, began in 1981 when Dr. Rubin and his colleagues started asking why bone is lost in aging and inactivity.

“Bone is notorious for ‘use it or lose it,’” Dr. Rubin said. “Astronauts lose 2 percent of their bone a month. People lose 2 percent a decade after age 35. Then you look at the other side of the equation. Professional tennis players have 35 percent more bone in their playing arm. What is it about mechanical signals that makes Roger Federer’s arm so big?”

At first, he assumed that the exercise effect came from a forceful impact — the pounding on the leg bones as a runner’s feet hit the ground or the blow to the bones in a tennis player’s arm with every strike of the ball. But Dr. Rubin was trained as a biomechanical engineer, and that led him to consider other possibilities. Large signals can actually be counterproductive, he said, adding: “If I scream at you over the phone, you don’t hear me better. If I shine a bright light in your eyes, you don’t see better.”

Over the years, he and his colleagues discovered that high-magnitude signals, like the ones created by the impact as foot hits pavement, were not the predominant signals affecting bone. Instead, bone responded to signals that were high in frequency but low in magnitude, more like a buzzing than a pounding.

That makes sense, he went on, because muscles quiver when they contract, and that quivering is the predominant signal to bones. It occurs when people stand still, for example, and their muscles contract to keep them upright. As people age, they lose many of those postural muscles, making them less able to balance, more apt to fall and, perhaps, prone to loss of bone.

“Bone is bombarded with little, teeny signals from muscle contractions,” Dr. Rubin said.

He discovered that in mice, sheep and turkeys, at least, standing on a flat vibrating plate led to bone growth. Small studies in humans — children with cerebral palsy who could not move much on their own and young women with low bone density — indicated that the vibrations might build bone in people, too.

The Xenith X1 football helmet aims to provide the next generation in concussion prevention:

The Xenith X1 football helmet is designed to reduce the sudden and violent acceleration and deceleration of the head and the brain after impact. A flexible bonnet is embedded with shock absorbers that gradually release air to dissipate the energy from impact. Traditional helmets use foam inserts.

In Diet and Fat: A Severe Case of Mistaken Consensus, John Tierney reviews Gary Taubes’s Good Calories, Bad Calories — which relies on many of the same ideas as Surowiecki’s The Wisdom of Crowds:

The notion that fatty foods shorten your life began as a hypothesis based on dubious assumptions and data; when scientists tried to confirm it they failed repeatedly. The evidence against Häagen-Dazs was nothing like the evidence against Marlboros.

It may seem bizarre that a surgeon general could go so wrong. After all, wasn’t it his job to express the scientific consensus? But that was the problem. Dr. Koop was expressing the consensus. He, like the architects of the federal “food pyramid” telling Americans what to eat, went wrong by listening to everyone else. He was caught in what social scientists call a cascade.

We like to think that people improve their judgment by putting their minds together, and sometimes they do. The studio audience at “Who Wants to Be a Millionaire” usually votes for the right answer. But suppose, instead of the audience members voting silently in unison, they voted out loud one after another. And suppose the first person gets it wrong.

If the second person isn’t sure of the answer, he’s liable to go along with the first person’s guess. By then, even if the third person suspects another answer is right, she’s more liable to go along just because she assumes the first two together know more than she does. Thus begins an “informational cascade” as one person after another assumes that the rest can’t all be wrong.

Because of this effect, groups are surprisingly prone to reach mistaken conclusions even when most of the people started out knowing better, according to the economists Sushil Bikhchandani, David Hirshleifer and Ivo Welch. If, say, 60 percent of a group’s members have been given information pointing them to the right answer (while the rest have information pointing to the wrong answer), there is still about a one-in-three chance that the group will cascade to a mistaken consensus.

Cascades are especially common in medicine as doctors take their cues from others, leading them to overdiagnose some faddish ailments (called bandwagon diseases) and overprescribe certain treatments (like the tonsillectomies once popular for children). Unable to keep up with the volume of research, doctors look for guidance from an expert — or at least someone who sounds confident.

The loud, confident, incorrect first voice came from Ancel Keys:

In the case of fatty foods, that confident voice belonged to Ancel Keys, a prominent diet researcher a half-century ago (the K-rations in World War II were said to be named after him). He became convinced in the 1950s that Americans were suffering from a new epidemic of heart disease because they were eating more fat than their ancestors.

There were two glaring problems with this theory, as Mr. Taubes, a correspondent for Science magazine, explains in his book. First, it wasn’t clear that traditional diets were especially lean. Nineteenth-century Americans consumed huge amounts of meat; the percentage of fat in the diet of ancient hunter-gatherers, according to the best estimate today, was as high or higher than the ratio in the modern Western diet.

Second, there wasn’t really a new epidemic of heart disease. Yes, more cases were being reported, but not because people were in worse health. It was mainly because they were living longer and were more likely to see a doctor who diagnosed the symptoms.

To bolster his theory, Dr. Keys in 1953 compared diets and heart disease rates in the United States, Japan and four other countries. Sure enough, more fat correlated with more disease (America topped the list). But critics at the time noted that if Dr. Keys had analyzed all 22 countries for which data were available, he would not have found a correlation. (And, as Mr. Taubes notes, no one would have puzzled over the so-called French Paradox of foie-gras connoisseurs with healthy hearts.)

Physicist shows how steroids can fuel home runs — with some fairly simple math:

Calculations show that, by putting on 10 percent more muscle mass, a batter can swing about 5 percent faster, increasing the ball’s speed by 4 percent as it leaves the bat.

Depending on the ball’s trajectory, this added speed could take it into home run territory 50 percent more often, said Roger Tobin of Tufts University in Boston.

“A 4 percent increase in ball speed, which can reasonably be expected from steroid use, can increase home run production by anywhere from 50 percent to 100 percent,” said Tobin, whose study will be published in an upcoming issue of the American Journal of Physics.

You don’t have to increase your average hitting distance much to double the tiny fraction of your hits that go over the wall.

Soccer beats jogging for fitness — which does not surprise me at all:

The researchers selected men with similar health profiles aged 31 to 33 and split them into groups of soccer players, joggers, and couch potatoes — who not surprisingly ended the three-month study in the worst shape.

Each period of exercise lasted about one hour and took place three times a week. After 12 weeks, researchers found that the body fat percentage in the soccer players dropped by 3.7 percent, compared to about 2 percent for the joggers.

The soccer players also increased their muscle mass by almost 4.5 pounds, whereas the joggers didn’t have any significant change. Those who did no exercise registered little change in body fat and muscle mass.

“Even though the football (soccer) players were untrained, there were periods in the game that were so intense that their cardiovascular was maximally taxed, just like professional football (soccer) players,” said Dr. Peter Krustrup, head of Copenhagen University’s department of exercise and sport sciences, who led the study.

The soccer players and the joggers had the same average heart rate, but the soccer players got a better workout because of intense bursts of activity. Krustrup and his colleagues found there were periods during soccer matches when the players’ hearts were pumping at 90 percent their full capacity. But the joggers’ hearts were never pushed as hard.

Unlike the soccer players, the joggers consistently thought their runs were exhausting.

“The soccer players were having more fun, so they were more focused on scoring goals and helping the team, rather than the feeling of strain and muscle pain,” Krustrup said.

Study finds any kind of exercise helps diabetics — which evidently comes as a surprise to some people:

Dr. Ronald Sigal of University of Calgary and colleagues at the University of Ottawa studied 251 people with type-2 diabetes aged 39 to 70. None exercised regularly.

They assigned them to one of four groups — one that did 45 minutes of aerobic training three times a week, another doing the same amount of resistance training, a group that did both, for a total of an hour and a half of exercise three days a week, and a fourth group that did no extra exercise.

The exercisers used treadmills or exercise bikes, or weight machines, at a health club. The volunteers liked the exercise and stuck with it, Sigal said.

“I think there is a widespread cynicism even among medical people that people will actually exercise,” Sigal said in a telephone interview.

They were given a diet to follow that should have prevented any weight loss, and then their blood sugar, cholesterol, weight and other vital statistics were measured.

Blood sugar levels fell with exercise and most importantly, hemoglobin A1c, which measures the blood sugar average for the past 3 months, fell by half a point on average in the people who did one form of exercise and a full point in those who did both.

A1c should be between 4 and 6 but the patients started out with A1c values ranging from 6.6 to 9.9, Sigal’s team wrote in the Annals of Internal Medicine.

A one point drop in A1c is associated with a 15 percent to 20 percent decrease in major cardiovascular events such as heart attack or stroke and a 37 percent reduction in complications such as kidney, eyes and limb damage.

“There were some who brought their A1c into the normal range,” Sigal said. Some also were able to lower their doses of medications and many lost weight and body fat.

“Imagine an inexpensive pill that could decrease the hemoglobin A1c value by 1 percentage point, reduce cardiovascular death by 25 percent, and substantially improve functional capacity (strength, endurance, and bone density),” Dr. William Kraus of Duke Medical School and Dr. Benjamin Levine of the University of Texas Southwestern Medical Center wrote in a commentary.

They said doctors should prescribe exercise to every diabetes patient.

Full fat milk makes you thinner:

Full fat dairy products are more likely to keep you slim than comparable low fat foods. That’s the apparently topsy-turvy conclusion of a new Swedish study, which shows that the fat encourages calcium uptake.

Researchers at Stockholm’s Karolinska Institute now reckon that daily consumption of full fat dairy products will lead to a reduction of obesity, reported Svenska Dagbladet.

he startling result was based on interviews with almost 20,000 women whose dietary habits have been tracked since 1987.

When the study began, the women had an average body mass index (BMI) of 23.7. Ten years later, the women who had regularly consumed full fat milk or cheese had a lower BMI than the rest of the group.

A glass of full fat milk every day will, according to the researchers, result in 15 percent less weight gain. But full fat cheese was an even more effective slimming product: one portion a day resulted in 30 percent less weight gain.

“The surprising conclusion was that increased consumption of cheese meant that overweight women lost weight,” said Alicja Wolk, professor at Karolinska Institute, to Svenska Dagbladet.

I was watching the season premiere of The Contender, when they decided to put the fighters through a series of high-tech Sparq Training tests to assess their power, agility, endurance, and reflexes. It was so very Rocky IV:

The lightboard test, which tests perception and reflexes, might make a good general screening tool, but it doesn’t test the sport-specific perception that’s crucial to high-level performance:

“Top tennis players can predict the direction and speed of the ball before it leaves the racket,” Farrow says. “So what is it these experts intuitively see that the rest of us don’t? What cues are they picking up on, and when?”

To understand what experts were seeing, Farrow meticulously dismantled the mechanics of the serve. He recruited two groups of players — novices and experts — and outfitted each with earmuffs and occlusion goggles, clear glasses that turn opaque when an assistant on the sidelines flips an electronic switch. He then put the athletes on court opposite an expert server. As the server’s arm went back for the shot, Farrow would black out the goggles, leaving players to swing blindly at the incoming ball.

The experiment was not for the faint of heart. Even relatively gentle serves arrived at 60 miles per hour, battering receivers who happened to step into the shot. “The men in particular got uneasy,” Farrow says dryly. He pulls out a faded photo of a man in tennis whites, standing in the ready position and peering through an oversize pair of plastic lenses. “You can see that he has a nervous grin on his face.”

The point of the exercise was to identify exactly when a seasoned player knew where the ball would head. Farrow established five possible windows: First, he blackened the goggles just as the ball’s flight path over the net was determined; second, as the server’s racket made contact with the ball. Then he gave players less and less information — cutting off the image when the server’s arm was cocked, as it was being drawn back, and, finally, at the very start of the toss.

Not surprisingly, receivers were better at guessing the ball’s direction the later their vision cut out. But the results also revealed something more interesting. Graphs of the amateurs’ reactions showed that they could anticipate where the ball would go only if they witnessed the racket making contact with it. Experts knew what would happen roughly a third of a second earlier, when the server’s cocked arm was still unfolding.

What happened in that fraction of a second? A lot, Farrow reasoned. Up to a point, he theorized, the direction of a serve was fundamentally unpredictable: Whatever clues existed weren’t ones that an opposing player could discern. By the time the ball had been hit, on the other hand, even a novice could make a plausible guess at its trajectory. What separated the pros from everyone else was the ability to pull directional information out of the early stages of a swing and therefore to predict a split second earlier where to head. This fraction of time is game- changing. A serve going 120 miles per hour takes approximately a third of a second to travel the 60 feet from baseline to service line. This means that an expert, who doesn’t have to wait until contact, has twice as long to move, plant his feet, and swing.

This discovery fit with something Farrow and other tennis researchers had already suspected: Reflex speed is not the key factor in returning a serve. “People have tested casual players and experts, and their reaction times are essentially the same,” Farrow says. The fact that Roger Federer can drill back a 140-mile-per-hour serve is partly a matter of muscle control. But it’s also about processing subtle visual cues to predict where the ball will go and get to the right spot.