Scientific American Topic - Exercise and Fitness

Readers Respond to "Fight the Frazzled Mind"--and More

Fri, 06 Jan 2012 11:00:00 EST

Older and More Stressed [More]

Two Big Myths about Grief

Thu, 05 Jan 2012 11:00:00 EST

Virtually all of us experience the loss of a loved one at some point in our life. So it is surprising that the serious study of grief is not much more than 30 years old. Yet in that time, we have made significant discoveries that have deepened our understanding of this phenomenon--and challenged widely held assumptions.

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Hit the Gym to Help Hit the Books

Tue, 03 Jan 2012 20:50:08 EST

All work and no play makes Jack a dull boy. And a worse student. Regular exercise--whether in gym class or less formally in a local park--has been shown to improve kids' mood and short-term focusing abilities. Now a new systematic analysis of numerous studies finds that keeping kids active also boosts their academic performance. The paper is in the Archives of Pediatric and Adolescent Medicine . [Amika Singh et al., " Physical Activity and Performance at School: A Systematic Review of the Literature Including a Methodological Quality Assessment "]

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This Way to Mars: How Technologies Borrowed from Robotic Missions Could Deliver Astronauts to Deep Space

Tue, 29 Nov 2011 08:00:00 EST

In October 2009 a small group of robotic space exploration geeks decided to venture out of our comfort zone and began brainstorming different approaches to flying people into space. We were spurred into action when the Augustine commission, a blue-ribbon panel that President Barack Obama set up earlier that year to review the space shuttle and its intended successor, reported that “the U.S. human spaceflight program appears to be on an unsustainable trajectory.” Having worked in an exciting robotic exploration program that has extended humanity’s reach from Mercury to the edge of the solar system, we wondered whether we might find technical solutions for some of NASA’s political and budgetary challenges.

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Atrazine in Water Tied to Hormonal Irregularities

Mon, 28 Nov 2011 14:10:00 EST

Women who drink water contaminated with low levels of the weed-killer atrazine may be more likely to have irregular menstrual cycles and low estrogen levels, scientists concluded in a new study.

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Good Science Always Has Political Ramifications

Thu, 24 Nov 2011 08:00:00 EST

When speaking about science to scientists, there is one thing that can be said that will almost always raise their indignation, and that is that science is inherently political and that the practice of science is a political act . Science, they will respond, has nothing to do with politics. But is that true?

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Prolonged Sitting Linked to Breast and Colon Cancers

Thu, 03 Nov 2011 18:05:00 EST

WASHINGTON -- Our culture of sitting may be responsible for 173,000 cases of cancer each year, according to new estimates.

Physical inactivity is linked to as many as 49,000 cases of breast cancer and 43,000 cases of colon cancer a year in the United States, said Christine Friedenreich, an epidemiologist at Alberta Health Services-Cancer Care in Canada.

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U.S. Glossed Over Cancer Concerns Associated with Airport X-Ray Scanners

Tue, 01 Nov 2011 16:05:00 EST

Look for a PBS NewsHour story on X-ray body scanners, reported in conjunction with ProPublica, to air later this month. [More]

Hidden Drivers of Childhood Obesity Operate Behind the Scenes

Mon, 31 Oct 2011 13:00:00 EST

Anxiety around children's eating habits often peaks during sweets-laden holidays like Halloween, but the factors that contribute to excess weight in kids extend well beyond special occasions. Most children who are obese--now 17 percent in the U.S.--will carry that extra heft into adulthood, along with the long-term health consequences. Scientists project that today's generation of children will live shorter lives than their parents and have higher rates of heart disease, diabetes and atherosclerosis. Despite diverse efforts--from First Lady Michelle Obama's Let's Move campaign to the U.S. Department of Agriculture's MyPlate nutrition guidance changes--the number of overweight and obese children does not seem to be dropping, which has sent scientists searching for other drivers of the childhood obesity epidemic. [More]

Should Scientists Use Genetically Modified Insects to Fight Disease?

Mon, 24 Oct 2011 10:00:00 EST

In the November 2011 issue of Scientific American, author Bijal Trivedi looks at the ongoing controversies surrounding the use of genetically modified mosquitoes to fight dengue fever. We asked biologist Mark Q. Benedict and Helen Wallace, the director of GeneWatch UK , to illuminate the issues surrounding the release of genetically modified insects into the wild.

Genetically Modified Mosquitoes Could Be an Important Tool in the Fight against Disease [More]

Answers in Your Dreams (preview)

Thu, 20 Oct 2011 15:30:00 EST

As a young mathematician in the 1950s, Don Newman taught at the Massachusetts Institute of Technology alongside rising star and Nobel-laureate-to-be John Nash. Newman had been struggling to solve a particular math problem: “I was ... trying to get somewhere with it, and I couldn’t and I couldn’t and I couldn’t,” he recalled.

One night Newman dreamed that he was reflecting on the problem when Nash appeared. The sleeping Newman related the details of the conundrum to Nash and asked if he knew the solution. Nash explained how to solve it. Newman awoke realizing he had the answer! He spent the next several weeks turning the insight into a formal paper, which was then published in a mathematics journal.

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The First Americans: Mounting Evidence Prompts Researchers to Reconsider the Peopling of the New World (preview)

Tue, 18 Oct 2011 10:30:00 EST

In the sweltering heat of an early July afternoon, Michael R. Waters clambers down into a shadowy pit where a small hive of excavators edge their trowels into an ancient floodplain. A murmur rises from the crew, and one of the diggers gives Waters, an archaeologist at the Center for the Study of the First Americans at Texas A&M University, a dirt-smeared fragment of blue-gray stone called chert. Waters turns it over in his hand, then scrutinizes it under a magnifying loupe. The find, scarcely larger than a thumbnail, is part of an all-purpose cutting tool, an ice age equivalent of a box cutter. Tossed away long ago on this grassy Texas creek bank, it is one among thousands of artifacts here that are pushing back the history of humans in the New World and shining rare light on the earliest Americans.

Waters, a tall, rumpled man in his mid-fifties with intense blue eyes and a slow, cautious way of talking, does not look or sound like a maverick. But his work is helping to topple an enduring model for the peopling of the New World. For decades scientists thought the first Americans were Asian big-game hunters who tracked mammoths and other large prey eastward across a now submerged landmass known as Beringia that joined northern Asia to Alaska. Arriving in the Americas some 13,000 years ago, these colonists were said to have journeyed rapidly overland along an ice-free corridor that stretched from the Yukon to southern Alberta, leaving behind their distinctive stone tools across what is now the contiguous U.S. Archaeologists called these hunters the Clovis people, after a site near Clovis, N.M., where many of their tools came to light.

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A Scientific Argument for Intervening in Nature

Fri, 14 Oct 2011 12:01:00 EST

Jessica Hellmann, an ecologist at Notre Dame University in Indiana, is in the midst of exactly the kind of painstaking study that can help guide those who want to move species . Hellmann works, among other places, on Vancouver Island, studying a kind of oak savanna ecosystem that most people associate with California. The star players of these savannas are called Garry oaks or Oregon white oaks, large trees often gnarled into unique shapes. Under their canopies grow mossy meadows of wildflowers, including buttercups and star- shaped blue camas. For Canadians, this kind of ecosystem is a beloved break from the evergreens that otherwise dominate the landscape. And according to the nonprofit Garry Oak Ecosystems Recovery Team, "approximately 100 species of plants, mammals, reptiles, birds, butterflies and other insects are officially listed as 'at risk' in these ecosystems" in Canada. The range of these Garry oak savannas hugs the Pacific coast from central California to just about halfway up Vancouver Island. These savannas are quite rare in Canada and threatened by land development. Hellmann thinks that British Columbians might be interested in establishing such ecosystems farther north on the island or even on the province's mainland as the climate warms. So one set of questions that her study is asking bears directly on whether such a move would work.

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Pickup Soccer Helps Homeless Health

Tue, 11 Oct 2011 12:50:08 EST

It sounds either really crazy, or kind of obvious. But according to new research, pick-up soccer could help homeless men avert the risk of an early death.

Homeless people are known to have poor health and life expectancy. Due to a variety of factors, including in large part cardiovascular disease. The homeless have high levels of hypertension and are more likely to be addicted to smoking, alcohol and other drugs. They also don’t spend much time in high-intensity physical exercise. Gyms, even when free, haven’t proven to be appealing.

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Putting Diabetes on Autopilot

Fri, 07 Oct 2011 08:00:00 EST

For millions of diabetes sufferers, life is a constant battle to keep their blood sugar balanced, which typically means they have to test their glucose levels and take insulin throughout the day. A new generation of “artificial pancreas” devices may make tedious diabetes micromanagement obsolete. In healthy people, the pancreas naturally produces insulin, which converts sugars and starches into energy. People with type 1 diabetes, however, do not produce any insulin of their own, and those with type 2 produce too little. All type 1 and many type 2 diabetics have to dose themselves with insulin to keep their bodies fueled--and doing so properly requires constant monitoring of blood sugar because appropriate dosages depend on factors such as how much patients eat or exercise. Stuart Weinzimer, an endocrinologist at Yale University, has devised an artificial pancreas that combines two existing technologies: a continuous glucose monitor, which uses an under-the-skin sensor to measure blood glucose levels every few minutes, and an insulin pump, which dispenses insulin through a tube that is also implanted under the skin. The glucose sensor sends its data wirelessly to a pocket computer a little bigger than an iPhone that is loaded with software developed by Minneapolis-based Medtronic. The program scans the incoming data from the glucose monitor and directs the pump to dispense the correct amount of insulin.

At an American Diabetes Association meeting in June, Weinzimer and his colleagues reported that 86 percent of type 1 diabetics they studied who used the artificial pancreas reached target blood glucose levels at night, whereas only 54 percent of subjects who had to wake up to activate an insulin pump reached their target levels. Other, similar systems are in development at Boston University, the University of Cambridge and Stanford University.

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Actuary of the Cell: A Q&A with Nobelist Elizabeth Blackburn on Telomeres and Aging Cells (preview)

Mon, 03 Oct 2011 08:02:00 EST

Big Picture : Blackburn has extended her Nobel Prize–winning work on telomeres to develop measures that aim to assess overall risks for heart disease, cancer and other chronic illnesses.

A molecular timepiece that resides inside each cell still makes headlines, decades after Elizabeth H. Blackburn conducted pioneering studies into how it works. The most recent experiments by Blackburn and other researchers have demonstrated that these cellular clocks, known as telomeres, may act as barometers of whether a person will remain healthy or not.

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3-D Printing Gets Ahead: Anthropologists Use Printing Technology to Model Fossils

Mon, 19 Sep 2011 08:00:00 EST

Animal corpses rarely defy the dictate of "ashes to ashes, dust to dust" to become fossils--and even if they do, they don't remain sturdy for long. By the time paleontologists get their hands on ancient remains, the fossils are incredibly fragile. So for decades, researchers have tended to do their close analyses with replicas instead. But in the past decade, 3-D printing has enabled a new solution: printing out copies of skulls and bones.

"My research is in the evolution of higher primates ," says paleoanthropologist Eric Delson, who uses digital models and an Objet Eden260 printer housed at Lehman College in New York City to produce models of primates' skeletons. 3-D printing allows him to make accurate replicas without damaging the originals, and to generate larger versions of fossils and even reconstructions of lost bones. In fact, the digital models that 3-D printers use as templates make it possible to re-create the remains of long-lost ancestral primates, putting classical model-making methods to shame by printing calculated re-creations of bones that failed to form fossils.

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Why Laughter May Be the Best Pain Medicine

Wed, 14 Sep 2011 11:55:00 EST

Laughing with friends releases feel-good brain chemicals, which also relieve pain, new research indicates.

Until now, scientists haven't proven that like exercise and other activities, laughing causes a release of so-called endorphins.

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How to Improve Your Life with Story Editing

Tue, 13 Sep 2011 09:00:00 EST

People can change -- but how? This is the central concern of “Redirect,” a new book by Timothy D. Wilson, a professor of psychology at the University of Virginia. Wilson offers a tour of recent scientific work on psychological change, with a focus on techniques that help a person who is struggling -- bad behavior, bad grades, bad attitudes -- find a new, better path. Again and again, Wilson asks: What actually works? The answers can be surprising. He spoke recently with Mind Matters editor Gareth Cook.

COOK: A central concept in your book is “story editing.” Can you please explain what you mean by this?

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Fight the Frazzled Mind: Proactive Steps Manage Stress (preview)

Thu, 08 Sep 2011 08:00:00 EST

“Desserts” spelled backward is “stressed.”Isn’t life like that? Even the good things in life--fine wine, rich food, sex--can stress you out.

There is just no escaping stress, and some experts even suggest that a little stress is good for you. In my view, that idea is flawed--the misleading result of averaging data across many individuals. Yes, high levels of stress are harmful to most people, adversely affecting health, mood and productivity. And yes, most people perform and feel better when faced with moderate levels of stress. And sure, very few people know how to be productive when they are not being pushed by stressors--but it can be done. Just as some people are able to perform well under highly stressful conditions (think Olympic athletes), it is also possible to perform well when relaxed (think masters of kung fu). That should be the goal, in my opinion: a life that is productive but also virtually stress-free.

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