If Your Brain Is Over 40, It Needs To Move

There was a time when I could hide my gray hairs with some strategic combing.  Now, I have succumbed and describe my new hair color as “executive blond.”  Of course, that also means that the important stuff under my scalp is getting older too.  Brains start to “go gray” about the same time the hair does, which is why exercise for older adults has become the new anti-aging fix for our senior cerebellums. Several new studies provide more evidence that a brain in motion tends to remain... young.

The older population (which does not include me yet!), persons 65 years or older, totaled 39.6 million in 2009 (the latest year for which data is available). They represented 12.9% of the U.S. population, about one in every eight Americans. By 2030, there will be about 72.1 million older persons, more than twice their number in 2000. People 65+ represented 12.4% of the population in the year 2000 but are expected to grow to be 19% of the population by 2030.

Over the last several years, dozens of studies have concluded that exercise helps not only your reflection in the mirror but also your cognitive ability.  Just in the last four months, three research projects, one small, one medium and one large, reported their findings of the effects of exercise on the older brain.

First up, a micro study of 16 women, aged 60 and over, hypothesized that a moderate exercise program would increase blood flow to the brain.  Dr. Rong Zhang, a researcher at the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas, first measured the blood flow in the women's internal carotid arteries, using Doppler ultrasonography.  Next, a baseline test was taken of their maximal oxygen consumption (VO2 max) to gauge their body’s ability to use oxygen during exercise.

Then the walking started.  Each woman was given a training plan based on their current fitness level that started with three 30-minute sessions per week of walking at a pace of 50-60% of their VO2 maximum.  By the third month, this was increased to four sessions at 70-80% of VO2 max.

A second blood flow test showed a significant increase in cerebral blood flow by an average of 15% in the women’s left carotid artery and 11% in the right artery.  VO2 max also went up by 13%, while their blood pressures and heart rates declined by 4% and 5%, respectively.

Dr. Zhang likes the correlation, "There are many studies that suggest that exercise improves brain function in older adults, but we don't know exactly why the brain improves. Our study indicates it might be tied to an improvement in the supply of blood flow to the brain."

So, what might that extra blood be doing for the brain?  Kirk Erickson, professor of psychology at the University of Pittsburgh, is convinced that exercise actually grows the size of the brain.  He and a cross-university team of scientists recruited 120 dementia-free, sedentary senior citizens to measure their brain size before and after a one year long walking program.  After measuring each volunteers’ hippocampus dimensions using magnetic resonance imaging (MRI), they were split into two groups.  One group would start a walking program of 40 minutes per session, three days per week, while the other group simply did a stretching and toning program.

After one year, a second MRI showed that the walkers increased their hippocampus size by an average of 2% while those that only stretched showed a decrease in brain volume of about 1.4%.  Also, a spatial memory test performed pre and post exercise showed a significant improvement for the walkers versus the stretchers.

"We think of the atrophy of the hippocampus in later life as almost inevitable," said Kirk Erickson, professor of psychology at the University of Pittsburgh and the paper's lead author. "But we've shown that even moderate exercise for one year can increase the size of that structure. The brain at that stage remains modifiable."

There is another important benefit to that extra blood flow, preventing strokes or even small brain lesions, or infarcts, often known as silent strokes.  "These 'silent strokes' are more significant than the name implies, because they have been associated with an increased risk of falls and impaired mobility, memory problems and even dementia, as well as stroke," said brain researcher Joshua Z. Willey, MD of Columbia University in New York.

Willey and his team asked 1,238 people over age 60, who had never had a stroke, about the frequency and intensity of their exercise regimen.  About 43 percent of the participants reported that they had no regular exercise; 36 percent did regular light exercise, such as golf, walking, bowling or dancing; and 21 percent performed regular moderate to intense exercise, such as hiking, tennis, swimming, biking, jogging or racquetball.

Six years later, all participants underwent an MRI scan of their brain.  Sixteen percent of the group, 197 volunteers, had suffered from an infarct or silent stroke during the time frame.  However, the moderate to intense exercise group was 40% less likely to have had the small lesions than the group that did not exercise at all.  There was no significant difference between those that did light exercise and those that did no exercise.

"Encouraging older people to take part in moderate to intense exercise may be an important strategy for keeping their brains healthy,” concluded Willey. "Of course, light exercise has many other beneficial effects, and these results should not discourage people from doing light exercise."

So, no excuses anymore.  Throw some hair color on your scalp, then go for that walk.  Your hair will look young and your brain will think young.


See also: Exercise Pumps Up Your Brain and Boomer Brains Need Exercise

Running Out Of Memory

Diane Van Deren

While the idea of running a marathon seems life-changing in a “bucket list” kind of way, the drudgery of a serious training plan can generate some second thoughts.  Even though the details of the weekday workouts vary, the one staple of most plans is the weekend “long run.”  

Consisting of progressively more miles as race day nears, these runs of 15+ miles train not only the legs and heart but also the brain.  Breaking through mental barriers and learning how to deal with fatigue helps the marathoner talk back to his or her body and helps them get over the inevitable psychological wall during the race.  

In fact, our brains can offer us too much information during those hours on the road.  Knowing that you just started mile three of an 18 mile training run can be just as difficult as approaching mile 15 exhausted but having to dig deep for three more.  What if you could turn your brain off and just deal with the current moment; no looking back or forward?  It is something Diane Van Deren lives with every day.

One of the world’s best ultra-runners (as in races of 50 miles or more), Van Deren puts in more miles on her feet during a week than many cyclists do in the saddle.  She is a veteran and champion of some of the world’s toughest 50 mile, 100 kilometer and 100 mile races.

But Van Deren fights her own personal battle every day.  In 1997, after suffering for years from epileptic seizures, she made the tough decision to undergo a lobectomy.  By isolating and removing a damaged kiwi-size portion of the right temporal lobe of her brain, the seizures stopped but so did significant pieces of her short term memory.  Beyond just embarrassing lapses of names and faces, Van Deren would lose keys, directions and experiences before they could be filed away into her long term memory archive.

During her struggles with seizures, the former pro tennis player would escape to running in the foothills of the Rockies as this would ward off an oncoming episode.  Now, she no longer runs from the attacks and instead runs for the joy of competition against the best in the world. Yet, her new battle is navigation and making her way home since any recollection of her path is gone after a few more strides.  She uses a system of “bread crumbs” and clues to find her way back.

The fascinating aspect of her new memory condition is the lack of awareness of distance traveled and distance to go.  There are no pre-planned workout distances that she dutifully fulfills until she’s reached that day’s goal.  Of course, a GPS or pedometer could tell her how far she has gone, but she prefers the blissful ignorance of running only to the sound of her feet on the ground.

“It’s a kinesthetic melody that she hits,” Don Gerber, a clinical neuropsychologist at Craig Hospital, a rehabilitation hospital in Englewood, Colo said in a New York Times piece. “And when she hits it, she knows she’s running well.”

But does her lack of memory provide some type of advantage to her perception of fatigue?  If you were on a 20 mile run, but did not know how far you had gone or how far you had to go, would your brain sense the same fatigue signals from your muscles?

In an in-depth Runner’s World article, several neuroscientists debated whether Diane’s lack of awareness of her effort increases her tolerance of pain.  "It's a mental state," Gerber says. "You become enmeshed in what you're doing. It's almost Zen. She can run for hours and not know how long she's been going."  Others argue that its not that simple. Dr. William Theodore, chief of the clinical epilepsy division at the National Institute of Health commented, "Certain parts of the brain are related to pain, but they're very deep structures. They're almost never involved in epilepsy surgery."

Still, imagine your peace if you were able to tune out the constant jabber of your inner voice telling you how you should feel based on objective data like miles or hours endured.  For those that grew up in the Great White North, you might remember playing for hours in the winter snow, only to be told when you finally come in the house that it was -15 degrees outside.  Without that data, you’re left to just your body’s messages about how you feel.

To get a sense of that peace, the incredible Radiolab podcast caught up with Van Deren last month for an interview but also to capture the soothing sound of her feet padding along a trail with a matching rhythm of breaths.  Sometimes its worth it to turn off the iPod, the heart monitor and the GPS and just run, focused only on yourself.

Back To The Beginning

It was just over three years ago that I wrote a short article called "The Sports Cognition Framework" for my squeaky new blog.  It was one of the first five articles I had ever written and it shows.  However, it captured the core of my passion and interest which is reflected in the name I chose for this blog, Sports Are 80 Percent Mental.  Learning about the connections between skill, psyche, and tactics in sports remains my goal.

Between that simple start and today's post (#185 for those scoring at home), I have wandered all across the spectrum of sports science, sports medicine, sports psychology and fitness research.  Along the way, there was a weekly column for Livescience.com and a few dozen articles for Life's Little Mysteries.

However, the focus of my writing has become blurred.  In a quest to get freelance articles placed online and expand the readership of this blog, I've tried covering an ever-increasing universe of sports research.  As with many endeavors, it is time to refocus on the original intent of this project.  It is time to get back to the beginning.

Most importantly, I value and appreciate your loyal visits to this site and your tweeting, liking and linking of the articles you enjoy.  I hope that will continue but wanted to give you a heads-up that future articles will be centered on the core concept of sports cognition.  Focused quality over quantity will be my mantra.

To that end, what questions do you have?  Have you thought about this stuff, too?  To be more specific, currently in the sports training world there is the popular, yet more general theory of "practice makes perfect" skill development, along with practical mental coaching tips and tricks.  What drives me, though, is drilling down much further into the brain-body connection and picking apart the root causes of sports expertise.

The research is there, buried in academic journals.  If it can be extracted, explained and extended out to coaches, parents and players, then we can break down some traditional training myths while developing a better understanding of the sports we love.

So, my humble request is that you give the more specific 80% Mental a chance by visiting, keeping your RSS subscription, and joining the conversation both here and on our Facebook page.

Thanks!
Dan

P.S. My breakthrough to re-purpose my work was inspired by a new manifesto from Steven Pressfield, appropriately titled, Do The Work.  The Kindle version is now selling at the very reasonable price of free, thanks to Seth Godin and the Domino Project.  I highly recommend it!

Exercise Grows Kids' Brains, Literally

Researchers have found an association between physical fitness and the brain in 9- and 10-year-old children: Those who are more fit tend to have a bigger hippocampus and perform better on a test of memory than their less-fit peers.  The new study, which used magnetic resonance imaging to measure the relative size of specific structures in the brains of 49 child subjects, appears in the journal Brain Research.

"This is the first study I know of that has used MRI measures to look at differences in brain between kids who are fit and kids who aren't fit," said University of Illinois psychology professor and Beckman Institute director Art Kramer, who led the study with doctoral student Laura Chaddock and kinesiology and community health professor Charles Hillman. "Beyond that, it relates those measures of brain structure to cognition."

The study focused on the hippocampus, a structure tucked deep in the brain, because it is known to be important in learning and memory. Previous studies in older adults and in animals have shown that exercise can increase the size of the hippocampus. A bigger hippocampus is associated with better performance on spatial reasoning and other cognitive tasks.

"In animal studies, exercise has been shown to specifically affect the hippocampus, significantly increasing the growth of new neurons and cell survival, enhancing memory and learning, and increasing molecules that are involved in the plasticity of the brain," Chaddock said.

Rather than relying on second-hand reports of children's physical activity level, the researchers measured how efficiently the subjects used oxygen while running on a treadmill.

"This is the gold standard measure of fitness," Chaddock said.

The physically fit children were "much more efficient than the less-fit children at utilizing oxygen," Kramer said.  When they analyzed the MRI data, the researchers found that the physically fit children tended to have bigger hippocampal volume -- about 12 percent bigger relative to total brain size -- than their out-of-shape peers.

The children who were in better physical condition also did better on tests of relational memory -- the ability to remember and integrate various types of information -- than their less-fit peers.

"Higher fit children had higher performance on the relational memory task, higher fit children had larger hippocampal volumes, and in general, children with larger hippocampal volumes had better relational memory," Chaddock said.

Further analyses indicated that a bigger hippocampus boosted performance on the relational memory task.

"If you remove hippocampal volume from the equation," Chaddock said, "the relationship between fitness and memory decreases."

The new findings suggest that interventions to increase childhood physical activity could have an important effect on brain development.  "We knew that experience and environmental factors and socioeconomic status all impact brain development," Kramer said. "If you get some lousy genes from your parents, you can't really fix that, and it's not easy to do something about your economic status. But here's something that we can do something about."

Source: University of Illinois at Urbana-Champaign and A neuroimaging investigation of the association between aerobic fitness, hippocampal volume and memory performance in preadolescent children. Brain Research, 2010; DOI: 10.1016/j.brainres.2010.08.049

See also: Fit Kids Get Better Grades and For Kids' Health, Just Let Them Play

Exercise Pumps Up Your Brain

Regular exercise speeds learning and improves blood flow to the brain, according to a new study led by researchers from the University of Pittsburgh School of Medicine that is the first to examine these relationships in a non-human primate model. The findings are available in the journal Neuroscience.

While there is ample evidence of the beneficial effects of exercise on cognition in other animal models, such as the rat, it has been unclear whether the same holds true for people, said senior author Judy L. Cameron, Ph.D., a psychiatry professor at Pitt School of Medicine and a senior scientist at the Oregon National Primate Research Center at Oregon Health and Science University. Testing the hypothesis in monkeys can provide information that is more comparable to human physiology.

"We found that monkeys who exercised regularly at an intensity that would improve fitness in middle-aged people learned to do tests of cognitive function faster and had greater blood volume in the brain's motor cortex than their sedentary counterparts," Dr. Cameron said. "This suggests people who exercise are getting similar benefits."

For the study, the researchers trained adult female cynomolgus monkeys to run on a human-sized treadmill at 80 percent of their individual maximal aerobic capacity for one hour each day, five days per week, for five months. Another group of monkeys remained sedentary, meaning they sat on the immobile treadmill, for a comparable time. Half of the runners went through a three-month sedentary period after the exercise period. In all groups, half of the monkeys were middle aged (10 to 12 years old) and the others were more mature (15 to 17 years old). Initially, the middle-aged monkeys were in better shape than their older counterparts, but with exercise, all the runners became more fit.


During the fifth week of exercise training, standardized cognitive testing was initiated and then performed five days per week until week 24. In a preliminary task, the monkeys learned that by lifting a cover off a small well in the testing tray, they could have the food reward that lay within it. In a spatial delay task, a researcher placed a food reward in one of two wells and covered both wells in full view of the monkey. A screen was lowered to block the animal's view for a second, and then raised again. If the monkey displaced the correct cover, she got the treat. After reliably succeeding at this task, monkeys that correctly moved the designated one of two different objects placed over side-by-side wells got the food reward that lay within it.

"Monkeys that exercised learned to remove the well covers twice as quickly as control animals," Dr. Cameron said. "Also, they were more engaged in the tasks and made more attempts to get the rewards, but they also made more mistakes."

She noted that later in the testing period, learning rate and performance was similar among the groups, which could mean that practice at the task will eventually overshadow the impact of exercise on cognitive function.

When the researchers examined tissue samples from the brain's motor cortex, they found that mature monkeys that ran had greater vascular volume than middle-aged runners or sedentary animals. But those blood flow changes reversed in monkeys that were sedentary after exercising for five months.

"These findings indicate that aerobic exercise at the recommended levels can have meaningful, beneficial effects on the brain," Dr. Cameron said. "It supports the notion that working out is good for people in many, many ways."

Source: University of Pittsburgh Schools of the Health Sciences.

See also: Take Your Brain To The Gym and Boomer Brains Need Exercise

Is Exercise The Cure For Depression?

Exercise is a magic drug for many people with depression and anxiety disorders, and it should be more widely prescribed by mental health care providers, according to researchers who analyzed the results of numerous published studies.


"Exercise has been shown to have tremendous benefits for mental health," says Jasper Smits, director of the Anxiety Research and Treatment Program at Southern Methodist University in Dallas. "The more therapists who are trained in exercise therapy, the better off patients will be."

Smits and Michael Otto, psychology professor at Boston University, based their finding on an analysis of dozens of population-based studies, clinical studies and meta-analytic reviews related to exercise and mental health, including the authors' meta-analysis of exercise interventions for mental health and studies on reducing anxiety sensitivity with exercise. The researchers' review demonstrated the efficacy of exercise programs in reducing depression and anxiety.

The traditional treatments of cognitive behavioral therapy and pharmacotherapy don't reach everyone who needs them, says Smits, an associate professor of psychology.

"Exercise can fill the gap for people who can't receive traditional therapies because of cost or lack of access, or who don't want to because of the perceived social stigma associated with these treatments," he says. "Exercise also can supplement traditional treatments, helping patients become more focused and engaged."

The researchers presented their findings March 6 in Baltimore at the annual conference of the Anxiety Disorder Association of America. Their workshop was based on their therapist guide "Exercise for Mood and Anxiety Disorders," (Oxford University Press, September 2009).

"Individuals who exercise report fewer symptoms of anxiety and depression, and lower levels of stress and anger," Smits says. "Exercise appears to affect, like an antidepressant, particular neurotransmitter systems in the brain, and it helps patients with depression re-establish positive behaviors. For patients with anxiety disorders, exercise reduces their fears of fear and related bodily sensations such as a racing heart and rapid breathing."

After patients have passed a health assessment, Smits says, they should work up to the public health dose, which is 150 minutes a week of moderate-intensity activity or 75 minutes a week of vigorous-intensity activity. At a time when 40 percent of Americans are sedentary, he says, mental health care providers can serve as their patients' exercise guides and motivators.

"Rather than emphasize the long-term health benefits of an exercise program -- which can be difficult to sustain -- we urge providers to focus with their patients on the immediate benefits," he says. "After just 25 minutes, your mood improves, you are less stressed, you have more energy -- and you'll be motivated to exercise again tomorrow. A bad mood is no longer a barrier to exercise; it is the very reason to exercise."

Smits says health care providers who prescribe exercise also must give their patients the tools they need to succeed, such as the daily schedules, problem-solving strategies and goal-setting featured in his guide for therapists.

"Therapists can help their patients take specific, achievable steps," he says. "This isn't about working out five times a week for the next year. It's about exercising for 20 or 30 minutes and feeling better today."


Source: Southern Methodist University

See also: Exercise May Help Schizophrenia Patients and Boomer Brains Need Exercise

Aerobic Fitness Helps Brains of Multiple Sclerosis Patients

Highly fit multiple sclerosis patients perform significantly better on tests of cognitive function than similar less-fit patients, a new study shows.  In addition, MRI scans of the patients showed that the fitter MS patients showed less damage in parts of the brain that show deterioration as a result of MS, as well as a greater volume of vital gray matter.

"We found that aerobic fitness has a protective effect on parts of the brain that are most affected by multiple sclerosis," said Ruchika Shaurya Prakash, lead author of the study and assistant professor of psychology at Ohio State University.  "As a result, these fitter patients actually show better performance on tasks that measure processing speed."

The study, done with colleagues Robert Motl and Arthur Kramer of the University of Illinois and Erin Snook of the University of Massachusetts, Amherst, appears online in the journal Brain Research and will be published in a future print edition.


The study involved 21 women diagnosed with relapsing-remitting MS. They were compared with 15 age- and education-matched healthy female controls. The study assessed fitness, cognitive function, and structural changes in all participants.  In order to measure fitness levels, the participants underwent a VO2 max test, in which they rode a stationary bicycle until they felt exhausted. During the test, they breathed into a mask which measured their oxygen consumption.

All the women also took a variety of tests designed to evaluate cognitive functions, such as processing speed and selective attention. In one test, for example, participants had to write down in one minute as many words as they could think of that began with the letter "F." MS patients generally perform poorly on these tests compared to healthy people.  The third analysis involved MRIs of the participants, revealing any damage to their brains.

As expected, the MS patients did much worse than the healthy controls on the tests of brain functioning, and showed more deterioration in their brains as revealed through the MRIs.  But what was interesting, Prakash said, was the significant differences between the more aerobically fit MS patients and those who were less fit.

Take, for instance, lesions, which are the characteristic feature of MS. Lesions are areas of inflammation in the central nervous system in which neurons have been stripped of myelin, an insulating protein.

"Physically fit MS patients had fewer lesions compared to those who weren't as fit and the lesions they did have tended to be smaller," Prakash said. "This is significant and can help explain why the higher-fit patients did better on tests of brain functioning."

Aerobic fitness was also associated with less-damaged brain tissue in MS patients, both the gray matter and white matter.  Gray matter is the cell bodies in the brain tissue, while white matter is the fibers that connect the various gray matter areas.

The study found that fitness in MS patients was associated with larger volume of gray matter, accounting for about 20 percent of the volume in gray matter. That's important, Prakash said, because gray matter is linked to brain processing skills.

"Even in gray matter that appeared relatively healthy, we found a deterioration in the volume in MS patients," she said. "But for some of the highest fit MS patients, we found that their gray matter volume was nearly equivalent to that of healthy controls."

Another MRI analysis involved the integrity of the white matter in the brain. In MS patients, the white matter deteriorates as the myelin is stripped from neurons. Again, higher-fit MS patients showed less deterioration of white matter compared to those who were less fit.

Overall, the three MRI tests in this study showed that parts of the brain involved in processing speed are all negatively affected by MS -- but less so in patients who are aerobically fit.

Prakash noted that other researchers have found that exercise promotes the production of nerve growth factors, proteins which are important for the growth and maintenance of neurs in the brain.  "Our hypothesis is that aerobic exercise enhances these nerve growth factors in MS patients, which increases the volume of the gray matter and increases the integrity of the white matter," she said.  "As a result there is an improvement in cognitive function."

Prakash and her colleagues plan to extend this research by studying whether exercise interventions with MS patients can actually improve their cognition and have positive physical effects on the brain.

"For a long time, MS patients were told not to exercise because there was a fear it could exacerbate their symptoms," she said.  "But we're finding that if MS patients exercise in a controlled setting, it can actually help them with their cognitive function."

The research was supported by a grant from the National Institute on Aging.

Source: Ohio State University
See also: Take Your Brain To The Gym,  Boomer Brains Need Exercise and Exercise May Help Schizophrenia Patients

Exercise May Help Schizophrenia Patients

Potentially beneficial brain changes (an increase in the volume of an area known as the hippocampus) occur in response to exercise both in patients with schizophrenia and healthy controls, according to a report in the February issue of Archives of General Psychiatry, one of the JAMA/Archives journals. The findings suggest that the brain retains some plasticity, or ability to adapt, even in those with psychotic disorders.

Schizophrenia is known to be associated with a reduced volume in the area of the brain known as the hippocampus, which helps regulate emotion and memory, according to background information in the article. "In contrast to other illnesses that may display psychotic features, such as bipolar disorder, schizophrenia is often characterized by incomplete recovery of psychotic symptoms and persistent disability," the authors write. "These clinical features of illness may relate to an impairment of neural plasticity or mechanisms of reorganizing brain function in response to a challenge."

The formation of new neurons is one component of plasticity; previous studies have shown that neuron growth in the hippocampus of healthy individuals can be stimulated by exercise. Frank-Gerald Pajonk, M.D., of The Saarland University Hospital, Homburg, and Dr. K. Fontheim's Hospital for Mental Health, Liebenburg, Germany, and colleagues assessed changes in hippocampal volume in response to an exercise program in both male patients with schizophrenia and men who had similar demographics and physical characteristics but did not have the condition.

Eight participants with schizophrenia and eight controls were randomly assigned to exercise (supervised cycling) three times per week for 30 minutes, whereas an additional eight patients with schizophrenia instead played tabletop football for the same period of time. The game enhances coordination and concentration but does not affect aerobic fitness. All participants underwent fitness testing, magnetic resonance imaging of the hippocampus, neuropsychological testing and other clinical measures before and after participating in the program for 12 weeks.

Following exercise training, hippocampal volume increased 12 percent in patients with schizophrenia and 16 percent in healthy controls. "To provide a context, the magnitude of these changes in volume was similar to that observed for other subcortical structures when patients were switched from typical to atypical antipsychotic drug therapy," the authors write. Conversely, patients with schizophrenia who played tabletop football instead of exercising experienced a 1 percent decrease in hippocampal volume.

Aerobic fitness also increased among all who exercised, and improvement in test scores for short-term memory was correlated with increases in hippocampal volume among patients and healthy controls.
"Further clinical studies are needed to determine if an incremental improvement in the disability related to schizophrenia could be obtained by incorporating exercise into treatment planning and lifestyle choice for individuals with the illness," the authors conclude.

Sources:  JAMA and Archives Journals  and  Hippocampal Plasticity in Response to Exercise in Schizophrenia

Stroke Patients Benefit From New Brain And Motor Skills Research

Bioengineers have taken a small step toward improving physical recovery in stroke patients by showing that a key feature of how limb motion is encoded in the nervous system plays a crucial role in how new motor skills are learned.

Published in a recent issue of Neuron, a Harvard-based study about the neural learning elements responsible for motor learning may help scientists design rehabilitation protocols in which motor adaptation occurs more readily, potentially allowing for a more rapid recovery.

Neuroscientists have long understood that the brain's primary motor cortex and the body's low-level peripheral stretch sensors encode information about the position and velocity of limb motion in a positively-correlated manner rather than as independent variables.

"While this correlation between the brain's encoding of the position and the velocity of motion is well-known, its potential importance and practical use has been unclear until now," says coauthor Maurice A. Smith, Assistant Professor of Bioengineering at the Harvard School of Engineering and Applied Sciences (SEAS) and the Center for Brain Science in the Faculty of Arts and Sciences.

Smith and colleagues showed that the correlated neural tuning to position and velocity is also present in the neural learning elements responsible for motor learning. Moreover, this correlated drive can explain key features of the motor adaptation process.

To study and record motor adaptation, the researchers had subjects grasp a robotic arm. The device was programmed to simulate novel physical dynamics as subjects made reaching motions. In addition, the team used a newly developed measurement technique called an "error-clamp" to tease apart the resulting data.

The method measures motor output during learning, allowing learning-related changes in motor output over the course of a movement to be dissociated from feedback adjustments that correct motor errors that happen simultaneously.

"Conceptually, this error-clamp is analogous to a voltage-clamp, commonly used in electrophysiology to measure how ions move through a neuron's membrane when it fires," explains lead author Gary C. Sing, a graduate student at SEAS. "The general idea is that devising an experimental method to clamp and control the key variable in an experiment can allow for greater insight into the underlying physiology."

Analysis of the data extracted by the error-clamp technique led to the creation of a computational model that identifies a set of vectors that characterize the principal components of motor adaptation in the state space of physical motion. While such analysis is commonplace in systems engineering -- for example, in evaluating how a bridge might react to high winds or earthquakes -- the method has only been recently applied to how motor output evolves.

"We observed that the initial stages of motor learning are often quick but non-specific, whereas later stages of learning are slower and more precise," says Sing. "Further, we saw that some physical patterns of movement are learned more quickly than others."

By understanding what types of motor adaptations are easier to learn, the researchers hope to design rehabilitation activities that will encourage patients to use an affected limb more.

"In stroke rehabilitation, patients who make a greater effort to use their impaired limbs can achieve better outcomes," says Smith. "However, there is often a vicious cycle, as a patient is far less likely to use an impaired limb if his or her other limb is fine. This pattern slows recovery and leads to greater impairment of the affected limb."

Smith and his colleagues are beginning studies with stroke patients to determine whether training them with such optimized patterns will, in fact, improve their rate of motor learning and speed up recovery.
More broadly, untangling the algorithms the brain uses for motor learning could help improve a wide range of neural and muscular rehabilitation programs. The researchers also anticipate that such findings could be one day be adapted for enhancing the brain/machine interfaces increasingly used for those with amputated limbs.

Sources:  Harvard University and "Primitives for Motor Adaptation Reflect Correlated Neural Tuning to Position and Velocity"

Boomer Brains Need Exercise

Moderate physical activity performed in midlife or later appears to be associated with a reduced risk of mild cognitive impairment, whereas a six-month high-intensity aerobic exercise program may improve cognitive function in individuals who already have the condition, according to two reports in the January issue of Archives of Neurology.

Mild cognitive impairment is an intermediate state between the normal thinking, learning and memory changes that occur with age and dementia, according to background information in one of the articles. Each year, 10 percent to 15 percent of individuals with mild cognitive impairment will develop dementia, as compared with 1 percent to 2 percent of the general population. Previous studies in animals and humans have suggested that exercise may improve cognitive function.

In one article, Laura D. Baker, Ph.D., of the University of Washington and Veterans Affairs Puget Sound Health Care System, Seattle, and colleagues report the results of a randomized, controlled clinical trial involving 33 adults with mild cognitive impairment (17 women, average age 70). A group of 23 were randomly assigned to an aerobic exercise group and exercised at high intensity levels under the supervision of a trainer for 45 to 60 minutes per day, four days per week. The control group of 10 individuals performed supervised stretching exercises according to the same schedule but kept their heart rate low. Fitness testing, body fat analysis, blood tests of metabolic markers and cognitive functions were assessed before, during and after the six-month trial.

A total of 29 participants completed the study. Overall, the patients in the high-intensity aerobic exercise group experienced improved cognitive function compared with those in the control group. These effects were more pronounced in women than in men, despite similar increases in fitness. The sex differences may be related to the metabolic effects of exercise, as changes to the body's use and production of insulin, glucose and the stress hormone cortisol differed in men and women.

"Aerobic exercise is a cost-effective practice that is associated with numerous physical benefits. The results of this study suggest that exercise also provides a cognitive benefit for some adults with mild cognitive impairment," the authors conclude. "Six months of a behavioral intervention involving regular intervals of increased heart rate was sufficient to improve cognitive performance for an at-risk group without the cost and adverse effects associated with most pharmaceutical therapies."

In another report, Yonas E. Geda, M.D., M.Sc., and colleagues at Mayo Clinic, Rochester, Minn., studied 1,324 individuals without dementia who were part of the Mayo Clinic Study of Aging. Participants completed a physical exercise questionnaire between 2006 and 2008. They were then assessed by an expert consensus panel, who classified each as having normal cognition or mild cognitive impairment.

A total of 198 participants (median or midpoint age, 83 years) were determined to have mild cognitive impairment and 1,126 (median age 80) had normal cognition. Those who reported performing moderate exercise—such as brisk walking, aerobics, yoga, strength training or swimming—during midlife or late life were less likely to have mild cognitive impairment. Midlife moderate exercise was associated with 39 percent reduction in the odds of developing the condition, and moderate exercise in late life was associated with a 32 percent reduction. The findings were consistent among men and women.

Light exercise (such as bowling, slow dancing or golfing with a cart) or vigorous exercise (including jogging, skiing and racquetball) were not independently associated with reduced risk for mild cognitive impairment.

Physical exercise may protect against mild cognitive impairment via the production of nerve-protecting compounds, greater blood flow to the brain, improved development and survival of neurons and the decreased risk of heart and blood vessel diseases, the authors note. "A second possibility is that physical exercise may be a marker for a healthy lifestyle," they write. "A subject who engages in regular physical exercise may also show the same type of discipline in dietary habits, accident prevention, adherence to preventive intervention, compliance with medical care and similar health-promoting behaviors."

Future study is needed to confirm whether exercise is associated with the decreased risk of mild cognitive impairment and provide additional information on cause and effect relationships, they conclude.

Sources:  JAMA and Archives Journals, Physical Exercise, Aging, and Mild Cognitive Impairment: A Population-Based Study  and Effects of Aerobic Exercise on Mild Cognitive Impairment: A Controlled Trial.

Ending The Myth Of The Dumb Jock

In the first study to demonstrate a clear positive association between adolescent fitness and adult cognitive performance, Nancy Pedersen of the University of Southern California and colleagues in Sweden find that better cardiovascular health among teenage boys correlates to higher scores on a range of intelligence tests – and more education and income later in life.

"During early adolescence and adulthood, the central nervous system displays considerable plasticity," said Pedersen, research professor of psychology at the USC College of Letters, Arts & Sciences. "Yet, the effect of exercise on cognition remains poorly understood."

Pedersen, lead author Maria Åberg of the University of Gothenburg and the research team looked at data for all 1.2 million Swedish men born between 1950 and 1976 who enlisted for mandatory military service at the age of 18.

In every measure of cognitive functioning they analyzed – from verbal ability to logical performance to geometric perception to mechanical skills – average test scores increased according to aerobic fitness.

However, scores on intelligence tests did not increase along with muscle strength, the researchers found.

"Positive associations with intelligence scores were restricted to cardiovascular fitness, not muscular strength," Pedersen explained, "supporting the notion that aerobic exercise improved cognition through the circulatory system influencing brain plasticity."

The results of the study – in the current issue of PNAS Early Edition – also show the importance of getting healthier between the ages of 15 and 18 while the brain is still changing.

Boys who improved their cardiovascular health between ages 15 to 18 exhibited significantly greater intelligence scores than those who became less healthy over the same time period. Over a longer term, boys who were most fit at the age of 18 were more likely to go to college than their less fit counterparts.

"Direct causality cannot be established. However, the fact that we demonstrated associations between cognition and cardiovascular fitness but not muscle strength . . . and the longitudinal prediction by cardiovascular fitness on subsequent academic achievement, speak in favor of a cardiovascular effect on brain function," Pedersen said.

In their sample, the researchers looked at 260,000 full-sibling pairs, 3,000 sets of twins, and more than 1,400 sets of identical twins. Having relatives enabled the research team to evaluate whether the results might reflect shared family environments or genetic influences.

Even among identical twin pairs, the link between cardiovascular health and intelligence remained strong, according to the study. Thus, the results are not a reflection of genetic influences on cardiovascular health and intelligence. Rather, the twin results give further support to the likelihood that there is indeed a causal relationship, Pedersen explained.

"The results provide scientific support for educational policies to maintain or increase physical education in school curricula," Pedersen said. "Physical exercise should be an important instrument for public health initiatives to optimize cognitive performance, as well as disease prevention at the society level."

Source: University of Southern California

Running Addicts Need Their Fix

Just as there is the endorphin rush of a "runner's high," there can also be the valley of despair when something prevents avid runners from getting their daily fix of miles.

Now, researchers at Tufts University may have confirmed this addiction by showing that an intense running regimen in rats can release brain chemicals that mimic the same sense of euphoria as opiate use. They propose that moderate exercise could be a "substitute drug" for human heroin and morphine addicts.

Given all of the benefits of exercise, many people commit to an active running routine. Somewhere during a longer, more intense run when stored glycogen is depleted, the pituitary gland and the hypothalamus release endorphins that can provide that "second wind" that keeps a runner going.

This sense of being able to run all day is similar to the pain-relieving state that opiates provide, scientists have known. So a team led by Robin Kanarek, professor of psychology at Tufts University, wondered whether they could also produce similar withdrawal symptoms, which would indicate that intense running and opiate abuse have a similar biochemical effect.

Running rodents
The team divided 44 male rats and 40 female rats into four groups. One group was housed inside an exercise wheel, and another group had none. Each group was divided again, either allowing access to food for only one hour per day or for 24 hours per day. Though tests on humans would be needed to confirm this research, rodents are typically good analogues to illuminate how the human body works.
The rodents existed in these environments for several weeks. Finally, all groups were given Naloxone, a drug used to counteract an opiate overdose and produce immediate withdrawal symptoms.

The active rats displayed a significantly higher level of withdrawal symptoms than the inactive rats. Also, the active rats that were only allowed food for one hour per day exercised the most and showed the most intense reaction to Naloxone. This scenario mimics the actions of humans suffering from anorexia athletica, also known as hypergymnasia, that causes an obsession not only with weight but also with continuous exercise to lose weight.

"Exercise, like drugs of abuse, leads to the release of neurotransmitters such as endorphins and dopamine, which are involved with a sense of reward," Kanarek said. "As with food intake and other parts of life, moderation seems to be the key. Exercise, as long as it doesn't interfere with other aspects of one's life, is a good thing with respect to both physical and mental health."

The study appears in the August issue of Behavioral Neuroscience, published by the American Psychological Association.

Treatment ideas
Kanarek hopes to use these results to design treatment programs for heroin and morphine addicts that substitute the all-natural high of exercise in place of the drugs.  "These findings, in conjunction with results of studies demonstrating that intake of drugs of abuse and running activates the endogenous opioid and dopamine reward systems, suggest that it might be possible to substitute drug-taking behavior with naturally rewarding behavior," she writes.

She also wants to do further research on understanding the neurophysiology of extreme eating and exercise disorders. "The high comorbidity of drug abuse and eating disorders provides further evidence of a common neurobiological basis for these disorders," Kanarek concludes.

Exercise Wins Again

It just seems too good to be true. Study after research study consistently promoting the endless benefits of exercise. Couch potatoes everywhere are waiting for the other shoe to drop, telling us that all of those scientists were wrong and we should remain as sedentary as possible.
Yet four additional studies released recently each give the same prescription for improving some aspect of your health: exercise.

They add to recent evidence that regular workouts can improve old brains, raise kids' academic performance and give a brain boost to everyone in between.

Better bones
One study illustrates the effect of exercise on preventing or limiting osteoporosis, which affects more than 200 million people worldwide. Researchers at the University of Missouri found that while both resistance training (lifting weights) and high impact exercise (running) both help build needed bone mineral density (BMD), running is the better choice.

"Exercise programs to increase bone strength should be designed using what is known about how bones respond to exercise," said Pam Hinton, associate professor and lead author. "Only the skeletal sites that experience increased stress from exercise will become stronger. High-impact, dynamic, multi-directional activities result in greater gains in bone strength."  The study was published in the February issue of the Journal of Strength Conditioning.

Less pain
In a related study, exercise seemed to be one of the few successful remedies for those that suffer from low-back pain. In the February issue of the Spine Journal, University of Washington physicians summarized 20 different clinical trials that promoted different solutions to alleviating pain.

"Strong and consistent evidence finds many popular prevention methods to fail while exercise has a significant impact, both in terms of preventing symptoms and reducing back pain-related work loss," said Dr. Stanley J. Bigos, professor emeritus of orthopaedic surgery and environmental health. "Passive interventions such as lumbar belts and shoe inserts do not appear to work."

Better eye health
Also, vigorous exercise has now been linked with significantly reduced onset of cataracts and age-related macular degeneration. In the study, detailed in Investigative Ophthalmology and Visual Science, researchers reviewed the eye health of 41,000 runners over seven years and found that both men and women had significantly lower rates of these two diseases than the general public.

Men who logged more than 5.7 miles per day had a 35 percent lower risk than those that ran less than 1.4 miles per day. While the correlation is strong, the reason is not clear.

"We know some of the physiological benefits of exercise, and we know about the physiological background of these diseases, so we need to better understand where there's an overlap," said Paul Williams, an epidemiologist in the Lawrence Berkeley National Laboratory Life Sciences Division.

Cancer prevention
Each year in the U.S., more 100,000 people are diagnosed with colon cancer. To see what effect exercise has on lowering this rate, researchers at Washington University and Harvard University combined to review 52 studies over the last 25 years which linked exercise and the incidence of cancer. Overall, they found that those that exercised the most (5-6 hours of brisk walking per week) were 24 percent less likely to develop the disease than those that exercised the least (less than 30 minutes per week).

"The beneficial effect of exercise holds across all sorts of activities," said lead study author Kathleen Y. Wolin, Sc.D. of Washington University. "And it holds for both men and women. There is an ever-growing body of evidence that the behavior choices we make affect our cancer risk. Physical activity is at the top of the list of ways that you can reduce your risk of colon cancer."

So, are there any studies out there that link exercise with a negative outcome?

In a recent study published in the journal Obesity, Dolores Albarracín, professor of psychology at the University of Illinois, did find that people who are shown posters with messages like "join a gym" or "take a walk" actually ate more after viewing these messages than those that saw messages like "make friends."

"Viewers of the exercise messages ate significantly more (than their peers, who viewed other types of messages)," Albarracín said. "They ate one-third more when exposed to the exercise ads."



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Take Your Brain To The Gym

The moment of truth has arrived, again. The holidays have passed, the bowl games are over and you have renewed your annual New Year's resolution to get back into shape... for real. Don't worry, you are not alone. According to the Centers for Disease Control (CDC), 63 percent of Americans have a Body Mass Index (BMI) in excess of 25 (defined as overweight), while a quarter are greater than 30 (obese).

Its not just kids that benefit from exercise. As we get older, those extra pounds start to affect other areas of our health, contributing to the onset of diabetes, hypertension and high cholesterol.

Several new studies in the last month have now built stronger links between our levels of physical activity and the health of our most important body part, the brain. Conditions such as dementia, Parkinson's, Alzheimer's and even mild age-related memory loss can be delayed by regular physical activity.

Shrinking brain

According to John Ratey, clinical associate professor of psychiatry at Harvard Medical School and author of "Spark: the revolutionary new science of exercise and the brain" (2008, Little, Brown), "Age happens. Getting older is unavoidable, but falling apart is not."

Starting at age 40, we lose about 5 percent of our brain volume per decade, but then at age 70 other conditions may start to accelerate the deterioration. As we age, our cells are less able to cope with stress from waste products such as free radicals.

In the brain, as this stress claims more neuron cells, the web of interconnections between neurons weakens. As we each have more than one hundred billion neurons with each having oodles of connections to other neurons, this gradual net loss is not as dramatic, at first. However, as we age, if this neurodegenerative process accelerates, then our general focus and memory loss as well as more serious conditions like Alzheimer's may appear.

What the aging brain needs is a pumped-up blood flow. Exercise-induced neurotrophins such as brain-derived neurotropic factor (BDNF), vascular endothelial growth factor (VEGF), as well as the neurotransmitter dopamine are needed to grow and fertilize new and existing neurons and their synapse connections. Ratay calls BDNF "Miracle-Gro for the brain."

Make new brain cells

Researchers at the National Cheng Kung University Medical College in Taiwan recently tested the effects of BDNF in the brains of mice of different ages. Half were trained to run a maze for 1 hour a day for exercise, while the control group did not exercise.

As expected, the researchers first found that neurogenesis, the creation of new neuron cells in the brain, dropped of dramatically in the middle-aged mice compared with younger mice. They also were able to conclude that exercise significantly slows down the loss of new nerve cells in the middle-aged mice.

Production of neural stem cells improved by approximately 200 percent compared to the middle-aged mice that did not exercise.

Increase blood flow

OK, that was mice. What about humans?  University of North Carolina brain researchers recently found that older adult humans who regularly exercised had increased blood flow in their brains. They compared long-time exercisers with sedentary adults using 3D MRI brain-scanning techniques.

"The active adults had more small blood vessels and improved cerebral blood flow," said the study's senior author, J. Keith Smith, associate professor of radiology at UNC School of Medicine. "These findings further point out the importance of regular exercise to healthy aging."

The research builds on a host of other studies, summarized in an August review, that show a balanced diet and regular exercise can protect the brain and ward off mental disorders.

Helps manage glucose

Finally, in a report released last month, Scott A. Small, associate professor of neurology at Columbia University Medical Center, found that levels of blood sugar (glucose) have a direct effect on blood flow in the brain.

By testing 240 elderly volunteers, and using functional magnetic resonance imaging (fMRI), Small and his colleagues found a correlation between elevated blood glucose levels and decreased cerebral blood flow, in the dentate gyrus, an area in the brain's hippocampus that has a direct effect on our memories. This corresponds with Smith's findings by showing that exercise may help manage glucose levels, which will improve blood flow to the brain.

Small's previous imaging studies have shown that physical exercise causes an improvement in dentate gyrus function.

"By improving glucose metabolism, physical exercise also reduces blood glucose" Small said. "We have a behavioral recommendation — physical exercise."

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