Broke Your Right Arm? Exercise Your Left. It May Help, Really.

Broke Your Right Arm? Exercise Your Left. It May Help, Really.

If you sprain an ankle or break a wrist this summer and cannot use one of your limbs, the muscles there will weaken and shrink — unless you exercise those same muscles in your other limb.

According to a fascinating new study, working out the muscles on one side of our bodies can keep the muscles on the other side strong and fit, even if we do not move them at all. The finding has implications for injury recovery and also underscores how capable and confounding our bodies can be.

Many of us — or a family member — will at some point break a bone, tear a ligament or experience a neurological problem such as a stroke that makes it impossible to move an arm or leg normally.

When that limb is immobilized, its muscles will atrophy, losing size and strength, a process that begins within days or even hours of an injury.

There have been hints, though, that exercising one limb can affect the other. In past studies, when someone pedals a bike with one leg or lifts weights with one arm, muscles in the other limb often contract, a development known as mirroring.

But in most of those experiments, the unused limb was not completely immobilized with a cast and scientists did not focus on specific muscles, making it difficult to know whether exercising certain muscles in one limb affects all muscles in the other or only some.

So for the new study, which was published in April in the Journal of Applied Physiology, researchers from the University of Saskatchewan in Canada gathered 16 male and female college students and closely examined their wrists.

Using ultrasound and CT scans, the scientists determined the precise dimensions of two separate sets of muscles in that joint: the extensors, which move the wrist back and away from the body; and the flexors, which pull it in, toward the forearm.

The researchers also tested each volunteers’ wrist strength using a weight machine for the hands.

Then they covered each student’s left forearm and wrist with a hard cast to freeze the wrist in place. (All of the students were right-handed.)

Half of the students were then asked to go on with their normal lives, ignoring the cast as much as possible and not exercising their arms.

The other eight students, though, began a workout program that targeted the flexor muscles in their wrists. Using a small, vise-like weight machine, they completed multiple, strenuous, eccentric contractions of those particular muscles. Eccentric contractions involve lengthening a muscle while contracting it and are known to potently build muscle strength and size.

In the meantime, the researchers attached tiny sensors above the flexor muscles in the volunteers’ immobilized wrists to measure any contractions there.

After a month, all of the volunteers returned to the lab, had their casts removed and repeated the original measures of their muscles.

As expected, the volunteers who had not exercised showed considerable muscle atrophy now. Their left wrist flexors were more than 20 percent weaker, on average.

Those muscles also had shrunk in size, dropping about 3 percent of their mass.

But the group that had exercised their right wrists’ flexor muscles had maintained almost all of those muscles’ original size and strength on the left.

The benefits were quite specific, though. These same volunteers’ wrist extensor muscles, which had not been exercised in their right wrists, were atrophied on the left.

The implication of these findings is that exercising muscles on one side of your body can lead to beneficial impacts on the other side, says Jonathan Farthing, an associate professor of kinesiology at the University of Saskatchewan who conducted the study with his graduate student Justin Andrushko and other colleagues.

But those effects apparently extend only to the particular muscles that are exercised.

And the entire process seems to involve more than just muscular mirroring, he says. The sensors placed above the volunteers’ cast-bound wrists picked up some muscular contractions in the left flexors when their right-side counterparts exercised.

“But those contractions were very slight,” he says, and by themselves are likely to be insufficient to keep the muscles healthy and strong.

He believes that there could be changes in the nervous system during unilateral exercise that somehow reach and change the same body part on the other side.

Various biochemical substances might also be released by the working muscles and make their way to the corresponding contralateral muscles, where they could jump-start physiological processes related to muscle health.

But how the substances would manage to target the specific muscles in question “is a mystery,” Dr. Farthing says.

He and his colleagues plan to investigate some of those issues in upcoming studies.

But for now, this experiment’s results strongly suggest that if you or a loved one winds up in a cast in the coming months, you may want to talk with your physician or physical therapist about exercising your uninjured limb, Dr. Farthing says.


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

Home DNA Tests and Your Privacy: Get the Facts

Home DNA Tests and Your Privacy: Get the Facts

Home DNA Tests and Your Privacy: Get the Facts

There have been several news stories lately about unauthorized use of personal data, covering an eclectic range of categories: credit-information breeches, selling of social-media information, and—most recently—the use of ancestry-related DNA databases to capture criminals, including the notorious Golden State Killer. In this age of “over-sharing” and paperless digital records, what about home DNA tests and privacy? Should you be concerned? Here are some facts.

Who Stores DNA Data and Why?


State Governments

Since 1983, approximately 4 million newborns in the U.S. each year are screened for a variety of congenital disorders—an early-detection practice performed in nearly all states that has saved thousands of lives. What is not commonly known is that, following screening, many states keep leftover DNA-rich specimens and maintain biobanks. DNA information can then be shared or sold for research purposes. Some states require that parents be informed of their right to request that a sample be destroyed, but not all. So concerns about keeping our genetic info private can start before we’re even old enough to realize it!


Most Americans are familiar with CODIS, a collection of FBI-managed databases containing millions of DNA profiles from convicted felons. Contributions to these databases come from federal, state, and local forensic labs. CODIS is an invaluable tool, since data can help law enforcement identify possible perpetrators, missing persons, and more.

Some Commercial Companies that Offer Home DNA Tests

There are providers of home DNA tests, specifically ancestry-related ones, that maintain databases accessible to anyone who pays for membership. Customers can opt out of making their DNA data accessible to other members, but if they want to maintain the privacy of their data, it is the customer who is responsible for ensuring they take that important step. Some companies also share or even sell data.

When trying to identify the Golden State killer, law enforcement accessed and used these types of DNA databases to narrow the field of possibilities for finding their man. More sophisticated forensic methods were then used to link Joseph James DeAngelo to the crimes committed by the notorious killer. DeAngelo’s distant relatives were unwittingly drawn into a cold-case investigation because their DNA was public.

The bottom line is: If you permit your data from DNA tests to be stored and then possibly shared either for genealogical, research, or other purposes, be advised your privacy is no longer ensured.

Tests by MightyDNA and your Privacy

At MightyDNA, we take the privacy of our customers’ data very seriously for all tests performed at our in-house laboratory. Here are some specific steps we take to earn your trust:

  •  All test samples (cheek swabs) are destroyed shortly after testing is complete
  • We only analyze and store data for the specific test that was ordered by the customer (we do not perform any other types of analysis on existing data)
  • We do not maintain publicly-accessible databases of ancestry-related or other data
  • We are committed to protecting the security of your information. We use a variety of industry-standard security technologies and procedures to help protect your information from unauthorized access, use, or disclosure
  • We do not share or sell any customer’s data with companies or entities that are not connected to MightyDNA. Because of this policy, no “opt out” is ever necessary for our customers

Some Final Thoughts about Home DNA Tests and Privacy

DNA technology offers endless possibilities in providing useful and sometimes life-changing information about ourselves, and it’s here to stay. So should you be concerned about your privacy? Home DNA tests are convenient, easy, and amazing tools for self-discovery, but it’s wise to do some research before choosing a DNA company and to become educated about its policies and practices. Not all companies are the same, and you are in control.

Do Fathers Who Exercise Have Smarter Babies?

Do Fathers Who Exercise Have Smarter Babies?

Exercise changes the brains and sperm of male animals in ways that later affect the brains and thinking skills of their offspring, according to a fascinating new study involving mice.

The findings indicate that some of the brain benefits of physical activity may be passed along to children, even if a father does not begin to exercise until adulthood.

We already have plenty of scientific evidence showing that exercise is good for our brains, whether we are mice or people. Among other effects, physical activity can strengthen the connections between neurons in the hippocampus, a crucial part of the brain involved in memory and learning. Stronger neuronal connections there generally mean sharper thinking.

Studies also indicate that exercise, like other aspects of lifestyle, can alter how genes work — whether and when they get turned on or off, for instance — and those changes can get passed on to children. This process is known as epigenetics.

But it had not been clear whether structural changes in the brain caused by exercise might also have epigenetic effects that would result in meaningful changes in the brains of the next generation.

In other words, would exercise by a parent help to produce smarter babies? And, in particular, would this process occur in males, who contribute sperm but not a womb and its multitude of hormones, cells and tissues to their children?

To find out, researchers at the German Center for Neurodegenerative Diseases in Göttingen, Germany, and other institutions gathered a large group of genetically identical male mice. Because the animals were genetically the same at the start, any differences in their bodies and behavior that cropped up later should be a result of lifestyle.

The mice all grew up sedentary.

But once they reached adulthood, half of them were moved to cages equipped with running wheels and other toys and games designed to stimulate their bodies and brains.

After the mice had been living in these fun-house homes for 10 weeks, scientists looked inside some of their brains and found that, as expected, they had developed stronger neuronal connections than were seen in the brains of the mice that had remained sedentary. The active mice also performed better on cognitive tests.

More interesting, when some of these active male mice mated with females that had not run, their pups were born with brains that, from the start, showed stronger neuronal connections in the hippocampus than did the brains of the babies born to sedentary fathers.

These animals also learned a bit faster and remembered a bit better than the mice with parents that had been inactive, even though none of the young animals ran.

Finally, the scientists delved into the makeup of the paternal sperm. Obviously, in order for a father’s lifestyle to affect the bodies of his unborn children, his sperm must change.

The scientists focused on microRNA, which are tiny molecules known to be involved in the inner workings of genes.

In earlier studies, other researchers had found that the levels of two particular microRNAs rise in the brains of mice after they start running, and these increases are thought to help jump-start the processes that lead to better connections between brain cells.

The German scientists now found heightened levels of these same two molecules in the brains of the running mice.

They also, for the first time, found them in the runners’ sperm.

Somewhat surprisingly, they did not find similarly high levels of those microRNA in the brains of the runners’ pups. In fact, those youngsters’ levels were about the same at birth and during childhood as in the babies born to sedentary dads.

And none of this second generation of mice, which never exercised, sired babies with notably strong neuronal connections. The epigenetic benefits from running ended when the running did.

What these findings suggest is that physical activity in one generation can have echoes in the brains and minds of the next, says André Fischer, a professor at the German Center for Neurodegenerative Diseases and senior author of the study, which was published in Cell Reports.

“We believe that the increased microRNA levels mediate mild changes in brain development that are beneficial” for thinking, he says.

But those impacts are unlikely to be perpetuated if the activity is not.

Of course, this study involved mice and not men and cannot tell us whether the same processes occur in people.

Dr. Fischer and his colleagues are planning, though, to look for the two relevant microRNA molecules in the blood and sperm of men who exercise and those who do not for an upcoming study, he says.

They also hope in future animal studies to tease out the individual effects of running from those of playing with toys and being otherwise mentally engaged, he says.

“My personal opinion is that exercise is probably much more important” than mental stimulation for altering brains and gene expression and potentially even the aptitudes of one’s offspring, Dr. Fischer says.



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

Even a Little Exercise Might Make Us Happier

Even a Little Exercise Might Make Us Happier

Small amounts of exercise could have an outsize effect on happiness.

According to a new review of research about good moods and physical activity, people who work out even once a week or for as little as 10 minutes a day tend to be more cheerful than those who never exercise. And any type of exercise may be helpful.

The idea that moving can affect our moods is not new. Many of us would probably say that we feel less cranky or more relaxed after a jog or visit to the gym.

Science would generally agree with us. A number of past studies have noted that physically active people have much lower risks of developing depression and anxiety than people who rarely move.

But that research centered on the relationships between exercise and psychological problems like depression and anxiety. Fewer past studies explored links between physical activity and upbeat emotions, especially in people who already were psychologically healthy, and those studies often looked at a single age group or type of exercise.

On their own, they do not tell us much about the amounts or types of exercise that might best lift our moods, or whether most of us might expect to find greater happiness with regular exercise or only certain groups of people.

So for the new review, in The Journal of Happiness Studies, researchers at the University of Michigan decided to aggregate and analyze multiple past studies of working out and happiness.

They began by combing research databases for relevant studies and wound up with 23 published since 1980. Most of those were observational, meaning that the scientists simply looked at a group of people, asking them how much they worked out and how happy they were. A few of the studies were experiments in which people started exercising and researchers measured their happiness before and after.

The number of participants in any one study was often small, but together, they represented more than 500,000 people ranging in age from adolescents to the very old and covering a broad range of ethnic and socioeconomic groups.

And for most of them, the Michigan researchers found, exercise was strongly linked to happiness.

“Every one of the observational studies showed a beneficial relationship between being physically active and being happy,” says Weiyun Chen, an associate professor of kinesiology at the University of Michigan, who, with her graduate student Zhanjia Zhang, wrote the review.

The type of exercise did not seem to matter. Some happy people walked or jogged. Others practiced yoga-style posing and stretching.

And the amount of exercise needed to influence happiness was slight, Dr. Chen says. In several studies, people who worked out only once or twice a week said they felt much happier than those who never exercised. In other studies, 10 minutes a day of physical activity was linked with buoyant moods.

But more movement generally contributed to greater happiness. If people exercised for at least 30 minutes on most days, which is the standard American and European recommendation for good health, Dr. Chen says, they were about 30 percent more likely to consider themselves happy than people who did not meet the guidelines.

“I think the indications are strong that exercise can contribute to happiness and, while anything helps, a bit more is probably better,” she says.

But because most of the studies in this review were observational, she says, it is not possible yet to establish whether exercise directly causes changes in happiness or if the two just happen to occur together often. It could be that happy people are more likely to take up exercise and continue with it than people who feel sad. In that case, exercise would not have helped to make people happy; rather, their happiness would have helped to make them exercisers.

Happiness also is an inherently subjective, squishy concept. The studies analyzed in the review asked people how happy they felt. But one person’s happiness could be another’s relative gloom, making it difficult to generalize about how any of us might react, emotionally, to starting an exercise routine.

And, of course, the review did not delve into how exercise could be influencing happiness.

“There are indications that social factors could mediate the effects of exercise on happiness for some people,” Dr. Chen says. In other words, the social interactions that occur during an exercise class or trip to the gym might help to elevate people’s moods.

Or exercise could more directly change the body, including the brain.

“We know that exercise improves health,” Dr. Chen says, “and feeling healthier might make people feel happier.”

Exercise might also remodel the brain, for example, by prompting the creation of new brain cells or inducing changes in brain chemicals, in ways that contribute to positive emotions.

Dr. Chen hopes that future experiments will explore these issues. But for now, she says, “I think that we can safely say that people who exercise are probably going to be happier than people who don’t.”



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