Archive for the ‘Exercise’ Category

If you are aiming to lose weight by revving up your exercise routine, it may be wise to think of your workouts not as exercise, but as playtime. An unconventional new study suggests that people’s attitudes toward physical activity can influence what they eat afterward and, ultimately, whether they drop pounds.

For some time, scientists have been puzzled — and exercisers frustrated — by the general ineffectiveness of exercise as a weight-loss strategy. According to multiple studies and anecdotes, most people who start exercising do not lose as much weight as would be expected, given their increased energy expenditure. Some people add pounds despite burning hundreds of calories during workouts.

Past studies of this phenomenon have found that exercise can increase the body’s production of appetite hormones, making some people feel ravenous after even a light workout and prone to consume more calories than they expended. But that finding, while intriguing, doesn’t fully explain the wide variability in people’s post-exercise eating habits.

So, for the new study, published in the journal Marketing Letters, French and American researchers turned to psychology and the possible effect that calling exercise by any other name might have on people’s subsequent diets.

In that pursuit, the researchers first recruited 56 healthy, adult women, the majority of them overweight. The women were given maps detailing the same one-mile outdoor course and told that they would spend the next half-hour walking there, with lunch to follow.

Half of the women were told that their walk was meant to be exercise, and they were encouraged to view it as such, monitoring their exertion throughout. The other women were told that their 30-minute outing would be a walk purely for pleasure; they would be listening to music through headphones and rating the sound quality, but mostly the researchers wanted them to enjoy themselves.

When the women returned from walking, the researchers asked each to estimate her mileage, mood and calorie expenditure.

Those women who’d been formally exercising reported feeling more fatigued and grumpy than the other women, although the two groups’ estimates of mileage and calories burned were almost identical. More telling, when the women sat down to a pasta lunch, with water or sugary soda to drink, and applesauce or chocolate pudding for dessert, the women in the exercise group loaded up on the soda and pudding, consuming significantly more calories from these sweets than the women who’d thought that they were walking for pleasure.

A follow-up experiment by the researchers, published as part of the same study, reinforces and broadens those findings. For it, the researchers directed a new set of volunteers, some of them men, to walk the same one-mile loop. Once again, half were told to consider this session as exercise. The others were told that they would be sightseeing and should have fun. The two groups covered the same average distance. But afterward, allowed to fill a plastic bag at will with M&M’s as a thank-you, the volunteers from the exercise group poured in twice as much candy as the other walkers.

Finally, to examine whether real-world exercisers behave similarly to those in the contrived experiments, the researchers visited the finish line of a marathon relay race, where 231 entrants aged 16 to 67 had just completed laps of five to 10 kilometers. They asked the runners whether they had enjoyed their race experience and offered them the choice of a gooey chocolate bar or healthier cereal bar in consideration of their time and help. In general, those runners who said that their race had been difficult or unsatisfying picked the chocolate; those who said that they had fun gravitated toward the healthier choice.

In aggregate, these three experiments underscore that how we frame physical activity affects how we eat afterward, said Carolina O.C. Werle, an associate professor of marketing at the Grenoble School of Management in France, who led the study. The same exertion, spun as “fun” instead of “exercise,” prompts less gorging on high-calorie foods, she said.

Just how, physiologically, our feelings about physical activity influence our food intake is not yet known, she said, and likely to be bogglingly complex, involving hormones, genetics, and the neurological circuitry of appetite and reward processing. But in the simplest terms, Dr. Werle said, this new data shows that most of us require recompense of some kind for working out. That reward can take the form of subjective enjoyment. If exercise is fun, no additional gratification is needed. If not, there’s chocolate pudding.

The good news is that our attitudes toward exercise are malleable. “We can frame our workouts in different ways,” Dr. Werle said, “by focusing on whatever we consider fun about it, such as listening to our favorite music or chatting with a friend” during a group walk.

“The more fun we have,” she concluded, “the less we’ll feel the need to compensate for the effort” with food.

http://well.blogs.nytimes.com/2014/06/04/losing-weight-may-require-some-serious-fun/?_php=true&_type=blogs&_r=0

By James Gorman

If an exercise wheel sits in a forest, will mice run on it?

Every once in a while, science asks a simple question and gets a straightforward answer.

In this case, yes, they will. And not only mice, but also rats, shrews, frogs and slugs.

True, the frogs did not exactly run, and the slugs probably ended up on the wheel by accident, but the mice clearly enjoyed it. That, scientists said, means that wheel-running is not a neurotic behavior found only in caged mice.

They like the wheel.

Two researchers in the Netherlands did an experiment that it seems nobody had tried before. They placed exercise wheels outdoors in a yard and in an area of dunes, and monitored the wheels with motion detectors and automatic cameras.

They were inspired by questions from animal welfare committees at universities about whether mice were really enjoying wheel-running, an activity used in all sorts of studies, or were instead like bears pacing in a cage, stressed and neurotic. Would they run on a wheel if they were free?

Now there is no doubt. Mice came to the wheels like human beings to a health club holding a spring membership sale. They made the wheels spin. They hopped on, hopped off and hopped back on.

“When I saw the first mice, I was extremely happy,” said Johanna H. Meijer at Leiden University Medical Center in the Netherlands. “I had to laugh about the results, but at the same time, I take it very seriously. It’s funny, and it’s important at the same time.”

Dr. Meijer’s day job is as a “brain electrophysiologist” studying biological rhythms in mice. She relished the chance to get out of the laboratory and study wild animals, and in a way that no one else had.

She said Konrad Lorenz, the great-grandfather of animal behavior studies, once mentioned in a letter that some of his caged rats had escaped and then returned to his garden to use running wheels placed there.

But, Dr. Meijer said, the Lorenz observation “was one sentence.”

For the experiment, the wheels were enclosed so that small animals could come and go but so that larger animals could not knock them over. Dr. Meijer set up motion sensors and automatic video cameras. Several years and 12,000 snippets of video later, she and Yuri Robbers, also a Leiden researcher, reported the results. They were released in the Proceedings of the Royal Society B.

Gene D. Block, chancellor of the University of California, Los Angeles, was not involved with the paper but knows Dr. Meijer and had seen the wheel set up in her garden. He said the study made it clear that wheel-running is “some type of rewarding behavior” and “probably not driven by stress or anxiety.”

Mice accounted for 88 percent of the wheel-running events, and spent one minute to 18 on the wheel. The other animals each accounted for less than 1 percent. Frogs, though there were very few, were seen to get on the wheel, get off and get back on.

Russell Foster, a circadian rhythm researcher at Oxford University, said he read the paper and sent it out to other scientists on behalf of the Proceedings and was delighted when peer reviews from other scientists were positive.

Marc Bekoff, a professor of ecology and evolutionary biology at the University of Colorado who is active in the animal welfare movement, said in an email that he thought the paper did show that wheel-running could be a “voluntary activity,” but that mice in labs may be doing more of it because of the stress of confinement.

“Wild bears will often pace back and forth,” he wrote, “but in captivity, the rate of doing it seems to be greatly heightened.”

As to why the mice, frogs or perhaps even slugs run, or move, on the wheel, Dr. Meijer said she thought that “there is an intrinsic motivation for animals, or should I say organisms, to be active.”

Huda Akil, co-director of the Molecular and Behavioral Neuroscience Institute at the University of Michigan, who has studied reward systems, said: “It’s not a surprise. All you have to do is watch a bunch of little kids in a playground or a park. They run and run and run.”

Dr. Akil said that in humans, running activates reward pathways in the brain, although she pointed out that there are innate differences in temperament in all sorts of animals, including humans. Rats that do not like to run can be bred. And plenty of people do all they can to avoid jogging, cycling and elliptical machines.

Presumably, the same is true of wild mice. While some were setting the wheel on fire with their exertions, others, out of camera range, may have been sprawled out on the mouse equivalent of a lounge chair, shaking their whiskers in dismay and disbelief.

Thanks to Dr. Nakamura for bringing this to the attention of the It’s Interesting community.

http://www.nytimes.com/2014/05/21/science/study-shows-that-mice-run-for-fun-not-just-for-lab-work.html?emc=eta1

exercise

New research explains how abstract benefits of exercise—from reversing depression to fighting cognitive decline—might arise from a group of key molecules.

While our muscles pump iron, our cells pump out something else: molecules that help maintain a healthy brain. But scientists have struggled to account for the well-known mental benefits of exercise, from counteracting depression and aging to fighting Alzheimer’s and Parkinson’s disease. Now, a research team may have finally found a molecular link between a workout and a healthy brain.

Much exercise research focuses on the parts of our body that do the heavy lifting. Muscle cells ramp up production of a protein called FNDC5 during a workout. A fragment of this protein, known as irisin, gets lopped off and released into the bloodstream, where it drives the formation of brown fat cells, thought to protect against diseases such as diabetes and obesity. (White fat cells are traditionally the villains.)

While studying the effects of FNDC5 in muscles, cellular biologist Bruce Spiegelman of Harvard Medical School in Boston happened upon some startling results: Mice that did not produce a so-called co-activator of FNDC5 production, known as PGC-1α, were hyperactive and had tiny holes in certain parts of their brains. Other studies showed that FNDC5 and PGC-1α are present in the brain, not just the muscles, and that both might play a role in the development of neurons.

Spiegelman and his colleagues suspected that FNDC5 (and the irisin created from it) was responsible for exercise-induced benefits to the brain—in particular, increased levels of a crucial protein called brain-derived neurotrophic factor (BDNF), which is essential for maintaining healthy neurons and creating new ones. These functions are crucial to staving off neurological diseases, including Alzheimer’s and Parkinson’s. And the link between exercise and BDNF is widely accepted. “The phenomenon has been established over the course of, easily, the last decade,” says neuroscientist Barbara Hempstead of Weill Cornell Medical College in New York City, who was not involved in the new work. “It’s just, we didn’t understand the mechanism.”

To sort out that mechanism, Spiegelman and his colleagues performed a series of experiments in living mice and cultured mouse brain cells. First, they put mice on a 30-day endurance training regimen. They didn’t have to coerce their subjects, because running is part of a mouse’s natural foraging behavior. “It’s harder to get them to lift weights,” Spiegelman notes. The mice with access to a running wheel ran the equivalent of a 5K every night.

Aside from physical differences between wheel-trained mice and sedentary ones—“they just look a little bit more like a couch potato,” says co-author Christiane Wrann, also of Harvard Medical School, of the latter’s plumper figures—the groups also showed neurological differences. The runners had more FNDC5 in their hippocampus, an area of the brain responsible for learning and memory.

Using mouse brain cells developing in a dish, the group next showed that increasing the levels of the co-activator PGC-1α boosts FNDC5 production, which in turn drives BDNF genes to produce more of the vital neuron-forming BDNF protein. They report these results online today in Cell Metabolism. Spiegelman says it was surprising to find that the molecular process in neurons mirrors what happens in muscles as we exercise. “What was weird is the same pathway is induced in the brain,” he says, “and as you know, with exercise, the brain does not move.”

So how is the brain getting the signal to make BDNF? Some have theorized that neural activity during exercise (as we coordinate our body movements, for example) accounts for changes in the brain. But it’s also possible that factors outside the brain, like those proteins secreted from muscle cells, are the driving force. To test whether irisin created elsewhere in the body can still drive BDNF production in the brain, the group injected a virus into the mouse’s bloodstream that causes the liver to produce and secrete elevated levels of irisin. They saw the same effect as in exercise: increased BDNF levels in the hippocampus. This suggests that irisin could be capable of passing the blood-brain barrier, or that it regulates some other (unknown) molecule that crosses into the brain, Spiegelman says.

Hempstead calls the findings “very exciting,” and believes this research finally begins to explain how exercise relates to BDNF and other so-called neurotrophins that keep the brain healthy. “I think it answers the question that most of us have posed in our own heads for many years.”

The effect of liver-produced irisin on the brain is a “pretty cool and somewhat surprising finding,” says Pontus Boström, a diabetes researcher at the Karolinska Institute in Sweden. But Boström, who was among the first scientists to identify irisin in muscle tissue, says the work doesn’t answer a fundamental question: How much of exercise’s BDNF-promoting effects come from irisin reaching the brain from muscle cells via the bloodstream, and how much are from irisin created in the brain?

Though the authors point out that other important regulator proteins likely play a role in driving BDNF and other brain-nourishing factors, they are focusing on the benefits of irisin and hope to develop an injectable form of FNDC5 as a potential treatment for neurological diseases and to improve brain health with aging.

http://news.sciencemag.org/biology/2013/10/how-exercise-beefs-brain

Thanks to Dr. Rajadhyaksha for bringing this to the attention of the It’s Interesting community.

statin

An important new study suggests that statins, the cholesterol-lowering medications that are the most prescribed drugs in the world, may block some of the fitness benefits of exercise, one of the surest ways to improve health. No one is saying that people with high cholesterol or a family history of heart disease should avoid statins, which studies show can be lifesaving. But the discovery could create something of dilemma for doctors and patients, since the people who should benefit the most from exercise — those who are sedentary, overweight, at risk of heart disease or middle-aged — are also the people most likely to be put on statins, possibly undoing some of the good of their workouts.

For the new study, which was published online in The Journal of the American College of Cardiology, researchers from the University of Missouri and other institutions gathered a group of overweight, sedentary men and women, all of whom had multiple symptoms of metabolic problems, including wide waistlines, high blood pressure or excess abdominal fat.

Most had slightly but not dangerously elevated cholesterol levels. None had exercised regularly in the past year. All underwent muscle biopsies and treadmill testing to determine their aerobic fitness — which was generally quite low — and agreed to continue with their normal diet. Then they all began a supervised 12-week exercise program, during which they visited the university lab five times a week and walked or jogged on a treadmill for 45 minutes at a moderately vigorous pace (about 65 to 70 percent of their individual aerobic maximum).

Half of the group also began taking a daily 40-milligram dose of simvastatin, a particular type of statin sold under the brand name Zocor. At the end of 12 weeks, the participants fitness and muscles were retested.

Statins, as most of us know, are medications designed to reduce the body’s cholesterol levels, particularly levels of low-density lipoprotein, or “bad” cholesterol. The drugs routinely are prescribed for those with high cholesterol and other risk factors for heart disease, and some physicians believe that they should be used prophylactically by virtually everyone over 50.

Exercise also typically is recommended as a means of fighting heart disease and prolonging life span.

And both statins and sweating indisputably are effective. In past studies, researchers have shown that statins reduce the risk of a heart attack in people at high risk by 10 to 20 percent for every 1-millimole-per-liter reduction in blood cholesterol levels (millimoles measure the actual number of cholesterol molecules in the bloodstream), equivalent to about a 40-point drop in LDL levels. Meanwhile, improving aerobic fitness by even a small percentage through exercise likewise has been found to lessen someone’s likelihood of dying prematurely by as much as 50 percent.

So, theoretically, it would seem that combining statins and exercise should provide the greatest possible health benefit. But until the current study, no experiment scrupulously had explored the interactions of statin drugs and workouts in people. And the results, as it turns out, are worrisome.

The unmedicated volunteers improved their aerobic fitness significantly after three months of exercise, by more than 10 percent on average. But the volunteers taking the statins gained barely 1 percent on average in their fitness, and some possessed less aerobic capacity at the end of the study than at its start.

Why there should be such a discrepancy between the two groups’ fitness levels wasn’t clear on the surface. But when the researchers looked microscopically at biopsied muscle tissue, they found notable differences in the levels of an enzyme related to the health of mitochondria, the tiny energy-producing parts of a cell. Mitochondria generally increase in number and potency when someone exercises.

But in the volunteers taking statins, enzyme levels related to mitochondrial health fell by about 4.5 percent over the course of the experiment. The same levels increased by 13 percent in the group not taking the drug. In effect, the volunteers taking statins “were not getting the same bang from their exercise buck” as the other exercisers, says John P. Thyfault, a professor of nutrition and exercise physiology at the University of Missouri and senior author of the study.

This finding joins a small but accumulating body of other studies indicating that statins can negatively affect exercise response. Lab rodents given statins, for instance, can’t run as far as unmedicated animals, while in humans, marathon runners on statins develop more markers of muscle damage after a race than runners not using the drugs.

None of which suggests, Dr. Thyfault says, that statins are not worthwhile. For people who have a family history of high cholesterol or heart disease or who themselves have high cholesterol, he says, “there’s no doubt that statins save lives.”

But for other people, the risk-benefit calculation involving statins may be trickier in light of this and other new science.

“Low aerobic fitness is one of the best predictors” of premature death, Dr. Thyfault says. And if statins prevent people from raising their fitness through exercise, then “that is a concern.”

A possible remedy, he continues, could be for people to get in shape and raise their aerobic fitness before starting the drug, but that’s an issue to discuss with your doctor. “There’s still a great deal we don’t understand” about how statins and exercise mix, he says.

http://well.blogs.nytimes.com/2013/05/22/can-statins-curb-the-benefits-of-exercise/

Thanks to Dr. Aarati Didwania for bringing this to the attention of the It’s Interesting community.

Next time you need motivation at the gym, think of Ray Williams.

The 6-foot, 361-pound Williams is a junior college football coach from Demopolis, Alabama. Over the weekend at the Alabama State Powerlifting Championship, he broke the U.S. record in the men’s raw 275-pounds-plus division by squatting 860 pounds. That’s right, 860 pounds.

And it gets better. Williams also put up 905 pounds, but that attempt was disallowed because he took a small jab step during the lift. Williams was pretty disappointed with himself because he wanted to see if he could squat 1,000 pounds.

For those wondering how to build bulk and muscle like Williams, the answer is simple: Cornbread and buttermilk.

“I’ve always been a big dude,” Williams told the website 70sbig. “And one thing my grandma brought us up on was cornbread, collard greens, good down-home southern food — it’s always been a staple of my diet.”

Making Williams’ feat all the more impressive was the fact that this was just his second powerlifting meet.

“I like it,” Williams told AL.com of powerlifting. “Just the fact that no one can say I’m big for no reason. Now, I can put my bigness to use. Plus I’ve always been just naturally strong, and I can refine that through powerlifting.”

http://www.thepostgame.com/blog/training-day/201302/man-produced-crazy-record-breaking-squat

 

Limbless French endurance athlete Philippe Croizon said Tuesday he wants to connect the world by swimming between five continents.

Croizon, who has previously crossed the English Channel, will spend the northern hemisphere summer swimming between the continents with his friend Arnaud Chassery — starting with a swim between Indonesia (Asia) and Papua New Guinea (Oceania) in May.

The pair will follow up by crossing the Red Sea between Jordan (Asia) and Egypt (Africa) and the Strait of Gibraltar between Africa and Europe, before finishing by crossing the Bering Strait between America and Asia in August.

“We are going to symbolically link the five continents, two little people like us, two little men, we’re going to be able to build a bridge between the continents,” Croizon said, according to the International Business Times.

“That means that we’re going to bring them together. Which means no one is very far from each other. So even if we have different political opinions, or skin colors, or even with our disabilities, we all live on the same planet. And that’s the clear message we want to send.”

On his website, Croizon — who lost his limbs after he was electrocuted while changing a TV antenna on his roof in 1994 — says the total distance covered by the swims will be roughly 53 miles and that the pair expect to be in the water for about 45 hours.

The 44-year-old swims using prosthetic limbs and fins attached to the stumps of his legs.

http://msn.foxsports.com/other/story/limbless-man-wants-to-swim-around-world-042412