Posts tagged exercise
Articles and news from the latest research reports.
Genetic Pre-Disposition Toward Exercise and Mental Development May be Linked
University of Missouri researchers have previously shown that a genetic pre-disposition to be more or less motivated to exercise exists. In a new study, Frank Booth, a professor in the MU College of Veterinary Medicine, has found a potential link between the genetic pre-disposition for high levels of exercise motivation and the speed at which mental maturation occurs.
For his study, Booth selectively bred rats that exhibited traits of either extreme activity or extreme laziness. Booth then put the rats in cages with running wheels and measured how much each rat willingly ran on their wheels during a six-day period. He then bred the top 26 runners with each other and bred the 26 rats that ran the least with each other. They repeated this process through 10 generations and found that the line of running rats chose to run 10 times more than the line of “lazy” rats.
Booth studied the brains of the rats and found much higher levels of neural maturation in the brains of the active rats than in the brains of the lazy rats.
“We looked at the part of the brain known as the ‘grand central station,’ or the hub where the brain is constantly sending and receiving signals,” Booth said. “We found a big difference between the amount of molecules present in the brains of active rats compared to the brains of lazy rats. This suggests that the active rats were experiencing faster development of neural pathways than the lazy rats.”
Booth says these findings may suggest a link between the genes responsible for exercise motivation and the genes responsible for mental development. He also says this research hints that exercising at a young age could help develop more neural pathways for motivation to be physically active.
“This study illustrates a potentially important link between exercise and the development of these neural pathways,” Booth said. “Ultimately, this could show the benefits of exercise for mental development in humans, especially young children with constantly growing brains.”
(Source: munews.missouri.edu)
Running, Cardio Activities in Young Adulthood May Preserve Thinking Skills in Middle Age
Young adults who run or participate in other cardio fitness activities may preserve their memory and thinking skills in middle age, according to a new study published in the April 2, 2014, online issue of Neurology®, the medical journal of the American Academy of Neurology. Middle age was defined as ages 43 to 55.
“Many studies show the benefits to the brain of good heart health,” said study author David R. Jacobs, Jr, PhD, with the University of Minnesota in Minneapolis. “This is one more important study that should remind young adults of the brain health benefits of cardio fitness activities such as running, swimming, biking or cardio fitness classes.”
Cardiorespiratory fitness is a measure of how well your body transports oxygen to your muscles, and how well your muscles are able to absorb the oxygen during exercise.
For the study, 2,747 healthy people with an average age of 25 underwent treadmill tests the first year of the study and then again 20 years later. Cognitive tests taken 25 years after the start of the study measured verbal memory, psychomotor speed (the relationship between thinking skills and physical movement) and executive function.
For the treadmill test, which was similar to a cardiovascular stress test, participants walked or ran as the speed and incline increased until they could not continue or had symptoms such as shortness of breath. At the first test, participants lasted an average of 10 minutes on the treadmill. Twenty years later, that number decreased by an average of 2.9 minutes. For every additional minute people completed on the treadmill at the first test, they recalled 0.12 more words correctly on the memory test of 15 words and correctly replaced 0.92 more numbers with meaningless symbols in the test of psychomotor speed 25 years later, even after adjusting for other factors such as smoking, diabetes and high cholesterol.
People who had smaller decreases in their time completed on the treadmill test 20 years later were more likely to perform better on the executive function test than those who had bigger decreases. Specifically, they were better able to correctly state ink color (for example, for the word “yellow” written in green ink, the correct answer was “green”).
“These changes were significant, and while they may be modest, they were larger than the effect from one year of aging,” Jacobs said. “Other studies in older individuals have shown that these tests are among the strongest predictors of developing dementia in the future. One study showed that every additional word remembered on the memory test was associated with an 18-percent decrease in the risk of developing dementia after 10 years.”
“These findings are likely to help us earlier identify and consequently prevent or treat those at high risk of developing dementia,” Jacobs said.
Scientists discover hormone released after exercise can ‘predict’ biological age
Scientists from Aston University have discovered a potential molecular link between Irisin, a recently identified hormone released from muscle after bouts of exercise, and the ageing process.
Irisin, which is naturally present in humans, is capable of reprograming the body’s fat cells to burn energy instead of storing it. This increases the metabolic rate and is thought to have potential anti-obesity effects which in turn could help with conditions such as type-2 diabetes.
The research team led by Dr James Brown have proven a significant link exists between Irisin levels in the blood and a biological marker of ageing called telomere length. Telomeres are small regions found at the end of chromosomes that shorten as cells within the body replicate. Short telomere length has been linked to many age-related diseases including cancer, heart disease and Alzheimer’s disease.
Using a population of healthy, non-obese individuals, the team has shown those individuals who had higher levels of Irisin were found to have longer telomeres. The finding provides a potential molecular link between keeping active and healthy ageing with those having higher Irisin levels more ‘biological young’ than those with lower levels of the hormone.
Dr James Brown from Aston’s Research Centre for Healthy Ageing, said; “Exercise is known to have wide ranging benefits, from cardiovascular protection to weight loss. Recent research has suggested that exercise can protect people from both physical and mental decline with ageing. Our latest findings now provide a potential molecular link between keeping active and a healthy ageing process.”
The Aston Research Centre for Healthy Ageing takes a multidisciplinary approach to successful ageing by asking how technological, therapeutic and psychosocial strategies can be employed to understand and arrest age-related decline and degeneration.
Exercise during pregnancy gives newborn brain development a head start
As little as 20 minutes of moderate exercise three times per week during pregnancy enhances the newborn child’s brain development, according to researchers at the University of Montreal and its affiliated CHU Sainte-Justine children’s hospital. This head-start could have an impact on the child’s entire life. “Our research indicates that exercise during pregnancy enhances the newborn child’s brain development,” explained Professor Dave Ellemberg, who led the study. “While animal studies have shown similar results, this is the first randomized controlled trial in humans to objectively measure the impact of exercise during pregnancy directly on the newborn’s brain. We hope these results will guide public health interventions and research on brain plasticity. Most of all, we are optimistic that this will encourage women to change their health habits, given that the simple act of exercising during pregnancy could make a difference for their child’s future.” Ellemberg and his colleagues Professor Daniel Curnier and PhD candidate Élise Labonté-LeMoyne presented their findings today at the Neuroscience 2013 congress in San Diego.
Not so long ago, obstetricians would tell women to take it easy and rest during their pregnancy. Recently, the tides have turned and it is now commonly accepted that inactivity is actually a health concern. “While being sedentary increases the risks of suffering complications during pregnancy, being active can ease post-partum recovery, make pregnancy more comfortable and reduce the risk of obesity in the children,” Curier explained. “Given that exercise has been demonstrated to be beneficial for the adult’s brain, we hypothesized that it could also be beneficial for the unborn child through the mother’s actions.”
To verify this, starting at the beginning of their second trimester, women were randomly assigned to an exercise group or a sedentary group. Women in the exercise group had to perform at least 20 minutes of cardiovascular exercise three times per week at a moderate intensity, which should lead to at least a slight shortness of breath. Women in the sedentary group did not exercise. The brain activity of the newborns was assessed between the ages of 8 to 12 days, by means of electroencephalography, which enables the recording of the electrical activity of the brain. “We used 124 soft electrodes placed on the infant’s head and waited for the child to fall asleep on his or her mother’s lap. We then measured auditory memory by means of the brain’s unconscious response to repeated and novel sounds,” Labonté-LeMoyne said. “Our results show that the babies born from the mothers who were physically active have a more mature cerebral activation, suggesting that their brains developed more rapidly.”
The researchers are now in the process of evaluating the children’s cognitive, motor and language development at age 1 to verify if these differences are maintained.
(Source: nouvelles.umontreal.ca)
How Exercise Beefs Up the Brain
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.
Exercise May be the Best Medicine for Alzheimer’s
New research out of the University of Maryland School of Public Health shows that exercise may improve cognitive function in those at risk for Alzheimer’s by improving the efficiency of brain activity associated with memory. Memory loss leading to Alzheimer’s disease is one of the greatest fears among older Americans. While some memory loss is normal and to be expected as we age, a diagnosis of mild cognitive impairment, or MCI, signals more substantial memory loss and a greater risk for Alzheimer’s, for which there currently is no cure.
The study, led by Dr. J. Carson Smith, assistant professor in the Department of Kinesiology, provides new hope for those diagnosed with MCI. It is the first to show that an exercise intervention with older adults with mild cognitive impairment (average age 78) improved not only memory recall, but also brain function, as measured by functional neuroimaging (via fMRI). The findings are published in the Journal of Alzheimer’s Disease.
“We found that after 12 weeks of being on a moderate exercise program, study participants improved their neural efficiency – basically they were using fewer neural resources to perform the same memory task,” says Dr. Smith. “No study has shown that a drug can do what we showed is possible with exercise.”
Recommended Daily Activity: Good for the Body, Good for the Brain
Two groups of physically inactive older adults (ranging from 60-88 years old) were put on a 12-week exercise program that focused on regular treadmill walking and was guided by a personal trainer. Both groups – one which included adults with MCI and the other with healthy brain function – improved their cardiovascular fitness by about ten percent at the end of the intervention. More notably, both groups also improved their memory performance and showed enhanced neural efficiency while engaged in memory retrieval tasks.
The good news is that these results were achieved with a dose of exercise consistent with the physical activity recommendations for older adults. These guidelines urge moderate intensity exercise (activity that increases your heart rate and makes you sweat, but isn’t so strenuous that you can’t hold a conversation while doing it) on most days for a weekly total of 150 minutes.
Measuring Exercise’s Impact on Brain Health and Memory
One of the first observable symptoms of Alzheimer’s disease is the inability to remember familiar names. Smith and colleagues had study participants identify famous names and measured their brain activation while engaged in correctly recognizing a name – e.g., Frank Sinatra, or other celebrities well known to adults born in the 1930s and 40s. “The task gives us the ability to see what is going on in the brain when there is a correct memory performance,” Smith explains.
Tests and imaging were performed both before and after the 12-week exercise intervention. Brain scans taken after the exercise intervention showed a significant decrease in the intensity of brain activation in eleven brain regions while participants correctly identified famous names. The brain regions with improved efficiency corresponded to those involved in the pathology of Alzheimer’s disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus.
The exercise intervention was also effective in improving word recall via a “list learning task,” i.e., when people were read a list of 15 words and asked to remember and repeat as many words as possible on five consecutive attempts, and again after a distraction of being given another list of words.
“People with MCI are on a very sharp decline in their memory function, so being able to improve their recall is a very big step in the right direction,” Smith states.
The results of Smith’s study suggest that exercise may reduce the need for over-activation of the brain to correctly remember something. That is encouraging news for those who are looking for something they can do to help preserve brain function.
Dr. Smith has plans for a larger study that would include more participants, including those who are healthy but have a genetic risk for Alzheimer’s, and follow them for a longer time period with exercise in comparison to other types of treatments. He and his team hope to learn more about the impact of exercise on brain function and whether it could delay the onset or progression of Alzheimer’s disease.
UMD Study Shows Exercise May Protect Against Future Emotional Stress
Moderate exercise may help people cope with anxiety and stress for an extended period of time post-workout, according to a study by kinesiology researchers in the University of Maryland School of Public Health published in the journal Medicine and Science in Sports and Exercise.
"While it is well-known that exercise improves mood, among other benefits, not as much is known about the potency of exercise’s impact on emotional state and whether these positive effects endure when we’re faced with everyday stressors once we leave the gym," explains J. Carson Smith, assistant professor in the Department of Kinesiology. "We found that exercise helps to buffer the effects of emotional exposure. If you exercise, you’ll not only reduce your anxiety, but you’ll be better able to maintain that reduced anxiety when confronted with emotional events."
Smith, whose research explores how exercise and physical activity affect brain function, aging and mental health, compared how moderate intensity cycling versus a period of quiet rest (both for 30 minutes) affected anxiety levels in a group of healthy college students. He assessed their anxiety state before the period of activity (or rest), shortly afterward (15 minutes after) and finally after exposing them to a variety of highly arousing pleasant and unpleasant photographs, as well as neutral images. At each point, study participants answered 20 questions from the State-Trait Anxiety inventory, which is designed to assess different symptoms of anxiety. All participants were put through both the exercise and the rest states (on different days) and tested for anxiety levels pre-exercise, post-exercise, and post-picture viewing.
Smith found that exercise and quiet rest were equally effective at reducing anxiety levels initially. However, once they were emotionally stimulated (by being shown 90 photographs from the International Affective Picture System, a database of photographs used in emotion research) for ~20 minutes, the anxiety levels of those who had simply rested went back up to their initial levels, whereas those who had exercised maintained their reduced anxiety levels.
"The set of photographic stimuli we used from the IAPS database was designed to simulate the range of emotional events you might experience in daily life," Smith explains. "They represent pleasant emotional events, neutral events and unpleasant events or stimuli. These vary from pictures of babies, families, puppies and appetizing food items, to very neutral things like plates, cups, furniture and city landscapes, to very unpleasant images of violence, mutilations and other gruesome things."
The study findings suggest that exercise may play an important role in helping people to better endure life’s daily anxieties and stressors.
Smith plans to explore if exercise could have the same persistent beneficial effect in patients who regularly experience anxiety and depression symptoms. In collaboration with the new Maryland Neuroimaging Center, he is also exploring the addition of functional magnetic resonance imaging, or fMRI, to measure brain activity during the period of exposure to emotionally stimulating images to see how exercise may alter the brain’s emotion-related neural networks.
Smith also investigates the role of exercise in preventing cognitive decline in older adults. His research has shown that physical activity promotes changes in the brain that may protect those at high risk for Alzheimer’s disease.
(Source: newsdesk.umd.edu)
If you start exercising, your brain recognizes this as a moment of stress. As your heart pressure increases, the brain thinks you are either fighting the enemy or fleeing from it. To protect yourself and your brain from stress, you release a protein called BDNF (Brain-Derived Neurotrophic Factor). This BDNF has a protective and also reparative element to your memory neurons and acts as a reset switch. That’s why we often feel so at ease and like things are clear after exercising.