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Recently, scientists in Germany gathered several groups of men and women to look at their cells’ life spans. Some of them were young and sedentary, others middle-aged and sedentary. Two other groups were, to put it mildly, active. The first of these consisted of professional runners in their 20s, most of them on the national track-and-field team, training about 45 miles per week. The last were serious, middle-aged longtime runners, with an average age of 51 and a typical training regimen of 50 miles per week, putting those young 45-mile-per-week sluggards to shame.

From the first, the scientists noted one aspect of their older runners. It ‘‘was striking,’’ recalls Dr. Christian Werner, an internal-medicine resident at Saarland University Clinic in Homburg, ‘‘to see in our study that many of the middle-aged athletes looked much younger than sedentary control subjects of the same age.’’ Read more…

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In November, a study appeared in The New England Journal of Medicine that should give pause to many athletic dopers and those who love them. The study examined the effects of Darbepoetin Alfa, one of a class of drugs commonly known as Epo that is used to stimulate the body’s production of red blood cells. In the experiment, more than 4,000 patients with diabetes, kidney disease and anemia were given either Epo or a placebo. The researchers were testing the impact of the drug when it was used as approved, at moderate doses in sick people. What they found, to their surprise, was that slightly more of the patients taking Epo suffered heart attacks than those in the placebo group, that nearly twice as many suffered a stroke and that the Epo group’s self-reported quality of life, their subjective sense of fatigue and illness, was barely better than with placebo.

“Going in, we had really expected” that Epo “would make people feel better and improve their outcomes,” says the study’s lead author Dr. Marc Pfeffer, a professor at Harvard University Medical School and senior physician at Brigham and Women’s Hospital in Boston. “We certainly had to reject that hypothesis.” Read more…

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Every four years, exercise-induced asthma draws special attention among scientists and the media, in lock step with the Winter Olympics. That’s because when the world’s premier cold-weather sports athletes convene in Vancouver for the 2010 Winter Olympics next month, they will share, as a group, not only exceptional fitness but also a disproportionate tendency to wheeze.

Exercise-induced asthma has been diagnosed in as many as half of all elite cross-country skiers and almost as many world-class ice skaters and hockey players. It’s far more common in winter athletes than in those who compete in the summer, although nearly 17 percent of Olympic-level distance runners have been given the same diagnosis. Read more…

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The idea that people can be overweight and yet still quite healthy began gaining scientific and popular credence some years ago, fueled by the publication of a number of studies showing that men and women who were a few pounds overweight but physically active had less risk of developing cardiac disease than people who were of normal weight but sedentary.

Some scientists and doctors began speculating that healthy people who were sporting extra pounds didn’t necessarily need to worry about losing weight. As one researcher told a reporter in 2004, “If a fat person or obese person has normal blood pressure, if their total cholesterol and glucose levels are normal and they are healthy, there is no reason they should necessarily have to lose weight.”

But several new studies are raising questions about that comforting notion at a very inopportune moment, with the holiday overindulgence season barely behind us. In the most recent of these studies, published online on Dec. 28 in the journal Circulation, Swedish researchers examined medical records reaching back 30 years for a group of more than 1,700 middle-aged men in the city of Uppsala. Read more…

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Recently researchers trawled through a vast database of survey information about the health and habits of men and women in Scotland, hoping to determine how much exercise is needed to keep the Scots from feeling gloomy (or in technical terms, experiencing “psychological distress”). The answer, according to a study published in this month’s British Journal of Sports Medicine: a mere 20 minutes a week of any physical activity, whether sports, walking, gardening or even housecleaning, the last not usually associated with bringing out the sunshine. The researchers found that more activity conferred more mental-health benefits and that “participation in vigorous sports activities” tended to be the “most beneficial for mental health.” But their overall conclusion was that being active for as little as 20 minutes a week is sufficient, if your specific goal is mental health.

The question of how much exercise is enough gains special piquancy at this time of year, when many of us dust off last year’s New Year’s resolutions and promise to be more diligent about working out in the coming year. Unfortunately, figuring out an ideal exercise dosage is not simple, in part because the amount of exercise needed depends on the benefits you hope to gain. Read more…

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For years, cardiologists were aware that heart attacks are more common during the winter months than in any other season. Most assumed that the cause was cold weather. But then researchers in California examined death certificates in Los Angeles County, an area not known for its inclement winters, and found that, even there, fatal heart attacks spiked during the winter months. More specifically, they started rising around Thanksgiving, climbed inexorably through Christmas and peaked on New Year’s Day. A subsequent study of death certificates nationwide, published in Circulation in 2004, confirmed the association between the two holidays and heart-attack deaths. It was accompanied by a cheery editorial headlined “The ‘Merry Christmas Coronary’ and ‘Happy New Year Heart Attack’ Phenomenon.”

Why the number of heart-attack deaths should surge so significantly during the holidays still is not clear, although cardiologists have some well-founded guesses. “We suspect there is often an inappropriate delay in seeking medical attention” at this time of year, says Dr. Robert A. Kloner, a professor of medicine at the University of Southern California, a cardiologist at Good Samaritan Hospital and the lead author of both the 2004 study of deaths in Los Angeles County and the accompanying editorial. “People ignore the pain in their chest,” perhaps because they don’t wish to disrupt the festivities or they misinterpret the ache as overindulgence, Dr. Kloner says. By the time they get to an emergency room, it’s too late to save them. Stress and tension likely play a role, too. “Spending time with family members can be trying,” he says. “And there are often concerns about financial issues, buying presents and so on.” Even a wood-burning fireplace, a romantic symbol of wintry, holiday evenings, could be a contributing factor, because particulate matter in the air has been connected to an increase in the risk of heart attacks, Dr. Kloner says.

A provocative new study published this year in the journal Heart and Circulatory Physiology suggests, however, that there may be a novel way to test at least one element of your heart’s health right in your own living room, right in the middle of the holidays. Sit on the floor with your legs stretched straight out in front of you, toes pointing up. Reach forward from the hips. Are you flexible enough to touch your toes? If so, then your cardiac arteries probably are also flexible.

Read more…

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Recently, researchers in the mountainous Bernese Oberland region of Switzerland, an area fabled for its snow sports, set out to discover why some people get hurt skiing and others don’t. They presented questionnaires to 782 skiers who had been treated at three local trauma centers and a comparable group of 496 skiers who hadn’t. What was it about the injured skiers that led to their accidents, the researchers wondered.

The answers, published last month in The British Journal of Sports Medicine, were, like familiar ski runs at dusk, both predictable and surprising. A majority of the injured skiers (57 percent of them) were men; their average age was 40. Many had been skiing slowly when they tumbled. But generally, their chance of injury increased when they had a high “readiness for risk,” or, in the words of Dr. Lorin Michael Benneker, an orthopedic surgeon at the University of Bern and one of the study’s authors, an eagerness to head for “jumps, moguls,” instead of “the easy slopes.” New ski equipment or old snow also significantly increased injury risk. Insobriety, however, did not. There was more self-admitted drinking among the control group of uninjured skiers. Drug use, on the other hand, contributed materially to injury risk. (A related, unpublished survey of injured snowboarders produced “similar risk factors” for accidents, Dr. Benneker says, including the finding that “smoking dope while boarding is a bad idea.”)

With the winter holidays rapidly approaching, and millions of skiers preparing to invade the nation’s slopes, it seems an opportune time to look at the demonstrable risks involved in the sport, and whether it’s possible to decrease your particular chances of exiting the slopes in an ambulance.

“There are a lot of misconceptions” about the dangers involved in skiing, says Jasper Shealy, professor emeritus of industrial and systems engineering at Rochester Institute of Technology, and one of the leaders of a team of researchers that has studied skiing injuries at a resort in Vermont for almost 40 years.

Read more…

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Recently, Dr. Constance R. Chu, the Albert Ferguson associate professor of orthopedic surgery at the University of Pittsburgh and director of the Cartilage Restoration Center there, confirmed a theory, and found herself troubled by the results. It turned out that if you dropped a heavy weight onto parts of a cow’s knee joint from various heights, the joint was hurt. (While the parts of the joint were damaged, the cow itself was uninjured by the experiment; the knees came from a local abattoir.) When the weight hit the joint’s surface cartilage with great speed and force, the bone and cartilage fractured. No surprise there. But it is what happened in Dr. Chu’s experiment when the impact was more subtle — closer to, for instance, the perturbations inside a human knee when a ligament is torn — that concerned her. She found that with lighter impact, the various parts of the knee appeared, visually at least, to be fine.

But when Dr. Chu and her colleagues examined the cartilage cells just below the placid surface, they found carnage. “Many of the cells within the impact zone” — the area that had been directly thwacked by the weight — “were dead,” she said. They died instantly. More insidiously, other cartilage cells, those outside the injury site, began to die in the hours and days after the impact. “We saw an expanding zone of death,” Dr. Chu said. By the end of her group’s planned observation period, four days after the impact, cartilage cells well away from the original injury site were still dying.

The results are fascinating, in a gruesome sort of way. But why should escalating damage to cows’ cartilage matter to the average active human? Well, Dr. Chu says, this study, which was just published in the December issue of The American Journal of Sports Medicine, in conjunction with other researchers’ findings, may help to explain why, she said, “I’m seeing so many patients in their 20s and 30s with knee arthritis after joint injury.”

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Stress fractures are one of the more pernicious injuries in sports, afflicting the experienced and the aspiring, with no regard for competitive timing. Last year, Tiger Woods managed to win the U.S. Open despite suffering from stress fractures in his left leg (as well as other leg and knee injuries), while the great British marathoner Paula Radcliffe struggled through the Beijing Olympics Marathon on a leg barely recovered from a stress fracture, one of several she’s suffered. The International Association of Athletics Federations, the world governing body for track and field, recently described stress fractures, with a kind of grim resignation, as “the curse of athletes.”

But studies published in this month’s issue of the journal Medicine & Science in Sports & Exercise offer hope that, at least for runners, simple alterations in their stride or in the strength of their legs might reduce their risk for the most common type of stress fracture.

Read more…

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For research published earlier this year, physiologists at Nebraska Wesleyan University had distance-running members of the school’s track and field team sit on the ground, legs stretched before them, feet pressed firmly up against a box; then the runners, both men and women, bent forward, reaching as far as they could past their toes. This is the classic sit-and-reach test, a well-established measurement of hamstring flexibility. The runners, as a group, didn’t have exceptional elasticity, although this varied from person to person.

Overall, the women were more supple, as might have been expected. Far more telling was the correlation between the various runners’ tight or loose hamstring muscles and their running economy, a measure of how much oxygen they used while striding. Economy is often cited as one of the factors that divide great runners from merely fast ones. Kenyan distance runners, for instance, have been found to be significantly more economical in their running than comparable Western elites. Read more…

Joubert/Photo Researchers, Inc A neuron in the brain.

Researchers at Princeton University recently made a remarkable discovery about the brains of rats that exercise. Some of their neurons respond differently to stress than the neurons of slothful rats. Scientists have known for some time that exercise stimulates the creation of new brain cells (neurons) but not how, precisely, these neurons might be functionally different from other brain cells.

In the experiment, preliminary results of which were presented last month at the annual meeting of the Society for Neuroscience in Chicago, scientists allowed one group of rats to run. Another set of rodents was not allowed to exercise. Then all of the rats swam in cold water, which they don’t like to do. Afterward, the scientists examined the animals’ brains. They found that the stress of the swimming activated neurons in all of the brains. (The researchers could tell which neurons were activated because the cells expressed specific genes in response to the stress.) But the youngest brain cells in the running rats, the cells that the scientists assumed were created by running, were less likely to express the genes. They generally remained quiet. The “cells born from running,” the researchers concluded, appeared to have been “specifically buffered from exposure to a stressful experience.” The rats had created, through running, a brain that seemed biochemically, molecularly, calm.

For years, both in popular imagination and in scientific circles, it has been a given that exercise enhances mood. But how exercise, a physiological activity, might directly affect mood and anxiety — psychological states — was unclear. Now, thanks in no small part to improved research techniques and a growing understanding of the biochemistry and the genetics of thought itself, scientists are beginning to tease out how exercise remodels the brain, making it more resistant to stress. Read more…

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Several weeks ago, The Journal of the American Medical Association published a study that should give pause to anyone who plans to live a long and independent life. The study looked at the incidence of hip fractures among older Americans and the mortality rates associated with them. Although the number of hip fractures has declined in recent decades, the study found that the 12-month mortality rate associated with the injury still hovers at more than 20 percent, meaning that, in the year after fracturing a hip, about one in five people over age 65 will die.

Meanwhile, another group of articles, published this month as a special section of Medicine & Science in Sports & Exercise, the journal of the American College of Sports Medicine, underscore why that statistic should be relevant even to active people who are years, or decades, away from eligibility for Medicare. The articles detailed a continuing controversy within the field of sports science about exactly how exercise works on bone and why sometimes, apparently, it doesn’t.

“There was a time, not so long ago,” when most researchers assumed “that any and all activity would be beneficial for bone health,” says Dr. Daniel W. Barry, an assistant professor of medicine at the University of Colorado, at Denver, and a researcher who has studied the bones of the elderly and of athletes. Read more…

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For some time, researchers have been finding that people who exercise don’t necessarily lose weight. A study published online in September in The British Journal of Sports Medicine was the latest to report apparently disappointing slimming results. In the study, 58 obese people completed 12 weeks of supervised aerobic training without changing their diets. The group lost an average of a little more than seven pounds, and many lost barely half that.

How can that be? Exercise, it seems, should make you thin. Activity burns calories. No one doubts that.

“Walking, even at a very easy pace, you’ll probably burn three or four calories a minute,” beyond what you would use quietly sitting in a chair, said Dan Carey, Ph.D., an assistant professor of exercise physiology at the University of St. Thomas in Minnesota, who studies exercise and metabolism.

But few people, an overwhelming body of research shows, achieve significant weight loss with exercise alone, not without changing their eating habits. A new study from scientists at the University of Colorado School of Medicine in Denver offers some reasons why. Read more…

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Recently, surgeons and emergency room physicians at the Rocky Mountain Regional Trauma Center in Denver noticed a troubling trend. They seemed to be seeing cyclists with more serious injuries than in years past. Since many of the physicians at the hospital, a Level I trauma center serving the Denver metropolitan area, were themselves cyclists, they wondered if their sense of things was accurate.

So the doctors began gathering data on all cycling-related trauma admittances at the hospital and dividing them into two blocks, one covering 1995-2000 and the other 2001-6.

The data, which were presented in mid-October at the 2009 Clinical Congress of the American College of Surgeons in Chicago, revealed “some pretty alarming things,” said Dr. Jeffry Kashuk, an associate professor of surgery at the University of Colorado School of Medicine, attending physician at the trauma center and an author of the study. Over the years, the severity of the bodily damage, as measured by a standardized injury severity score, had significantly increased. The number of chest injuries rose by 15 percent, while abdominal injuries tripled. The typical length of cyclists’ time in the intensive care unit grew. Meanwhile, the average age of the injured riders had risen, from 25 to about 30, and when the researchers plotted the most recent injury sites against a map of the Denver area, they found smatterings of accidents along bike paths, but large clusters downtown.

“What we concluded was that a lot of these people were commuters,” Dr. Kashuk said, adding, “If we keep promoting cycling without other actions to make it safer, we may face a perfect storm of injuries in the near future.”

There has been an enormous push in recent years to increase bicycle ridership, in hopes of improving both individual health and the environment. Cities like Denver, New York and Portland, Ore., have added bike lanes, given away helmets and otherwise tried to lure more cyclists onto the roads. But the Denver study seemed to indicate that getting more people to ride meant more would be hurt.

But that is not necessarily so, a well-established body of counterintuitive science promises. This research, which has examined bicycle-riding patterns in the United States and in Europe, has found that in virtually every instance, when the number of riders on the road increases, the likelihood of accidents declines. Read more…