Poor air quality does not offset exercise's heart benefits

July 18, 2018

Science Daily/American Heart Association

Even in areas with moderate to high levels of traffic pollution, regular physical activity reduced the risk of first and recurrent heart attack

"While exercise is known to reduce cardiovascular disease risk; pollution can increase the risk of cardiovascular disease, including heart attacks, asthma and chronic obstructive lung disease," said Nadine Kubesch, Ph.D., lead author and researcher at the University of Copenhagen in Denmark. "Currently there is little data on whether poor air quality cancels out the protective benefits of physical activity in preventing heart attacks."

Researchers in Denmark, Germany and Spain evaluated outdoor physical activity levels (sports, cycling, walking and gardening) and nitrogen dioxide (NO2 pollutant generated by traffic) exposure in 51,868 adults, age 50-65, comparing self-reported activities and lifestyle factors against heart attack. Over a 17.7-year period, there were 2,936 first heart attacks and 324 recurrent heart attacks.

To estimate average NO2 exposure, researchers used national traffic pollution monitoring data for each participants' address and found:

·     Higher levels of were associated with more heart attacks, however, the risk was lower among those who were physically active.

·     Moderate cycling for four or more hours per week cut risk for recurrent heart attack by 31 percent; and there was a 58 percent reduction when all four types of physical activity (together totaling four hours per week or more) were combined, regardless of air quality.

·     Those who participated in sports had a 15 percent lower rate of initial heart attacks and there was a 9 percent risk reduction associated with cycling, regardless of air quality

·     Compared to participants with low residential NO2 exposure, those in higher risk areas had a 17 percent increase risk in first heart attack and 39 percent for recurrent heart attack.

In participants who developed a heart attack (first or recurrent), the average NO2 exposure level was 18.9 micrograms per cubic meter air (μg/m3) with an overall average of 18.7 μg/m3, which is below the current NO2 European Union exposure guideline (50 μg/m3 over 24 hours).

"Our study shows that physical activity even during exposure to air pollution, in cities with levels similar to those in Copenhagen, can reduce the risk of heart attack," Kubesch said. "Our research supports existing evidence that even moderate levels of regular physical activity, such as active commuting, are sufficiently intense to get these health benefits.

https://www.sciencedaily.com/releases/2018/07/180718082228.htm

15-minutes of exercise creates optimal brain state for mastering new motor skills

Exercise increases brain connectivity and efficiency

July 11, 2018

Science Daily/McGill University

A recent study demonstrates that exercise performed immediately after practicing a new motor skill improves its long-term retention. More specifically, the research shows, for the first time, that as little as a single fifteen-minute bout of cardiovascular exercise increases brain connectivity and efficiency. It's a discovery that could, in principle, accelerate recovery of motor skills in patients who have suffered a stroke or who face mobility problems following an injury.

If you want to learn to walk a tightrope, it's a good idea to go for a short run after each practice session. That's because a recent study in NeuroImage demonstrates that exercise performed immediately after practicing a new motor skill improves its long-term retention. More specifically, the research shows, for the first time, that as little as a single fifteen-minute bout of cardiovascular exercise increases brain connectivity and efficiency. It's a discovery that could, in principle, accelerate recovery of motor skills in patients who have suffered a stroke or who face mobility problems following an injury.

In his earlier work, Marc Roig, the senior author on the study, had already demonstrated that exercise helps consolidate muscle or motor memory. What he and the McGill-based research team sought to discover this time was why exactly this was the case. What was going on in the brain, as the mind and the muscles interacted? What was it that helped the body retain motor skills?

A muscular video game

To find out, the research team asked study participants to perform two different tasks. The first, known as a "pinch task" is a bit like a muscular video game. It consists of gripping an object akin to a gamers' joystick (and known as a dynamometer) and using varying degrees of force to move a cursor up and down to connect red rectangles on a computer screen as quickly as possible. The task was chosen because it involved participants in motor learning as they sought to modulate the force with which they gripped the dynamometer to move the cursor around the screen. This was then followed by fifteen minutes of exercise or rest.

Participants were then asked to repeat an abridged version of this task, known as a handgrip task, at intervals of 30, 60, 90 minutes, after exercise or rest, while the researchers assessed their level of brain activity. This task involved participants in simply repeatedly gripping the dynamometer, for a few seconds, with a similar degree of force to that which was used to reach some of the target rectangles in the "pinch task". The final step in the study involved participants in both groups repeating the "pinch task" eight and then twenty-four hours after initially performing it, allowing the researchers to capture and compare brain activity and connectivity as the motor memories were consolidated.

More efficient brain activity

The researchers discovered that those who had exercised were consistently able to repeat the "pinch task" connecting different areas of the brain more efficiently and with less brain activity than those who hadn't exercised. More importantly, the reduction of brain activity in the exercise group was correlated with a better retention of the motor skill twenty-four hours after motor practice. This suggests that even a short bout of intense exercise can create an optimal brain state during the consolidation of motor memory which improves the retention of motor skills.

When they looked more specifically at what was going on, the researchers discovered that, after exercise, there was less brain activity, most likely because the neural connections both between and within the brain hemispheres had become more efficient.

"Because the neural activation in the brains of those who had exercised was much lower," explains Fabien Dal Maso, the first author on the paper, "the neural resources could then be put to other tasks. Exercise may help free up part of your brain to do other things."

The importance of sleep

What the researchers found especially intriguing was that when they tested participants at the 8 hour mark, there was little difference between groups in skill retention. In fact both groups were less able to retain the skills they had newly acquired, than they were at the twenty-four mark when the difference between the two groups was once more apparent.

"What this suggests to us, and this is where we are going next with our research, is that sleep can interact with exercise to optimize the consolidation of motor memories," says Marc Roig, the senior author on the paper. "It is very exciting to be working in this area right now because there is still so much to be learnt and the research opens doors to health interventions that can potentially make a big difference to people's lives."

https://www.sciencedaily.com/releases/2018/07/180711153607.htm

It's official -- spending time outside is good for you

July 6, 2018

Science Daily/University of East Anglia

Living close to nature and spending time outside has significant and wide-ranging health benefits -- according to new research. A new report reveals that exposure to greenspace reduces the risk of type II diabetes, cardiovascular disease, premature death, preterm birth, stress, and high blood pressure.

A new report published today reveals that exposure to greenspace reduces the risk of type II diabetes, cardiovascular disease, premature death, preterm birth, stress, and high blood pressure.

Populations with higher levels of greenspace exposure are also more likely to report good overall health -- according to global data involving more than 290 million people.

Lead author Caoimhe Twohig-Bennett, from UEA's Norwich Medical School, said: "Spending time in nature certainly makes us feel healthier, but until now the impact on our long-term wellbeing hasn't been fully understood.

"We gathered evidence from over 140 studies involving more than 290 million people to see whether nature really does provide a health boost."

The research team studied data from 20 countries including the UK, the US, Spain, France, Germany, Australia and Japan -- where Shinrin yoku or 'forest bathing' is already a popular practice.

'Green space' was defined as open, undeveloped land with natural vegetation as well as urban greenspaces, which included urban parks and street greenery.

The team analysed how the health of people with little access to green spaces compared to that of people with the highest amounts of exposure.

"We found that spending time in, or living close to, natural green spaces is associated with diverse and significant health benefits. It reduces the risk of type II diabetes, cardiovascular disease, premature death, and preterm birth, and increases sleep duration.

"People living closer to nature also had reduced diastolic blood pressure, heart rate and stress. In fact, one of the really interesting things we found is that exposure to greenspace significantly reduces people's levels of salivary cortisol -- a physiological marker of stress.

"This is really important because in the UK, 11.7 million working days are lost annually due to stress, depression or anxiety."

"Forest bathing is already really popular as a therapy in Japan -- with participants spending time in the forest either sitting or lying down, or just walking around. Our study shows that perhaps they have the right idea!

"Although we have looked at a large body of research on the relationship between greenspace and health, we don't know exactly what it is that causes this relationship.

"People living near greenspace likely have more opportunities for physical activity and socialising. Meanwhile, exposure to a diverse variety of bacteria present in natural areas may also have benefits for the immune system and reduce inflammation.

"Much of the research from Japan suggests that phytoncides -- organic compounds with antibacterial properties -- released by trees could explain the health-boosting properties of forest bathing."

Study co-author Prof Andy Jones, also from UEA, said: "We often reach for medication when we're unwell but exposure to health-promoting environments is increasingly recognised as both preventing and helping treat disease. Our study shows that the size of these benefits can be enough to have a meaningful clinical impact."

The research team hope that their findings will prompt doctors and other healthcare professionals to recommend that patients spend more time in greenspace and natural areas.

Twohig-Bennett said: "We hope that this research will inspire people to get outside more and feel the health benefits for themselves. Hopefully our results will encourage policymakers and town planners to invest in the creation, regeneration, and maintenance of parks and greenspaces, particularly in urban residential areas and deprived communities that could benefit the most."

'The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes' is published in the journal Environmental Research on 6 July.

https://www.sciencedaily.com/releases/2018/07/180706102842.htm

Don't let depression keep you from exercising

June 27, 2018

Science Daily/UT Southwestern Medical Center

Exercise may be just as crucial to a depression patient's good health as finding an effective antidepressant.

A new study of nearly 18,000 participants found that those with high fitness at middle age were significantly less likely to die from heart disease in later life, even if they were diagnosed with depression.

The research -- a collaboration between UT Southwestern and The Cooper Institute -- underscores the multiple ways in which depression may ultimately impact health and mortality. It also highlights the importance of overcoming a common dilemma among patients: How does one cope with hopelessness and still find motivation to exercise?

"Maintaining a healthy dose of exercise is difficult, but it can be done. It just requires more effort and addressing unique barriers to regular exercise," says Dr. Madhukar Trivedi, co-author of the study and Director of the Center for Depression Research and Clinical Care, part of the Peter O'Donnell Jr. Brain Institute at UT Southwestern.

Doctor's Tips: How to Stay Fit While Treating Depression

Dr. Madhukar Trivedi cites previous research showing that depressed patients can often perform about three-fourths of the exercise they're asked to do. He recommends patients take several steps to boost their chances of success:

·     Set aside a consistent time to exercise every day, but do not get discouraged by stretches of inactivity. Resume activities as soon as possible.

·     Keep a log to track progress.

·     Vary the exercises to avoid monotony. Keep the workout interesting and fun.

·     Exercise with a friend.

·     Task someone with holding you accountable for maintaining the exercise regimen.

The study published in the Journal of the American Medical Association Psychiatry utilized a Cooper Institute database of participants who had their cardiorespiratory fitness measured at an average age of 50 years. Researchers used Medicare administrative data to establish correlations between the participants' fitness at midlife to rates of depression and heart disease in older age. Among the findings, participants with high fitness were 56 percent less likely to eventually die from heart disease following a depression diagnosis.

Dr. Trivedi says the findings are just as relevant to younger age groups, in particular college-age adults who are just entering the workforce.

"This is the age where we typically see physical activity drop off because they're not involved in school activities and sports," Dr. Trivedi says.

"The earlier you maintain fitness, the better chance of preventing depression, which in the long run will help lower the risk of heart disease."

Depression has been linked to several other chronic medical conditions such as diabetes, obesity, and chronic kidney disease, which studies show can affect whether antidepressants are likely to help. For patients with these conditions, the more appropriate treatment may be exercise.

Dr. Trivedi says the reasons behind this may partly be connected to the general health effects of physical activity, including the fact that exercise decreases inflammation that may cause depression. By reducing inflammation, the risk for depression and heart disease are lowered.

"There is value to not starting a medication if it's not needed," says Dr. Trivedi, who's leading a national effort to establish biological tests for choosing antidepressants. "Being active and getting psychotherapy are sometimes the best prescription, especially in younger patients who don't have severe depression."

Dr. Trivedi cites previous research showing that depressed patients can often perform about three-fourths of the exercise they're asked to do. He recommends patients take several steps to boost their chances of success:

"There is enough evidence to show that the effect of low fitness on depression and heart disease is real," Dr. Trivedi says. "But further study is needed to establish the mechanism by which this effect happens."

More about Depression:

·     JAMA study: Fitness at midlife

·     STRIDE study: Fitness and addiction

·     Video: Bringing help straight to schools

·     Video: EEG helps guide treatment

·     Self-test: Are you depressed?

Dr. Trivedi is a Professor of Psychiatry who holds the Betty Jo Hay Distinguished Chair in Mental Health and the Julie K. Hersh Chair for Depression Research and Clinical Care. He collaborated with Dr. Benjamin Willis of The Cooper Institute for the JAMA Psychiatry study.

"These new insights demonstrate the ongoing importance of fitness throughout the lifespan," says Dr. Willis, Director of Epidemiology at The Cooper Institute and lead author of the study. "Now we know that the long-term benefits, and the connection between mind-body wellness, are more significant than we thought. We hope our study will highlight the role of fitness and physical activity in early prevention efforts by physicians in promoting healthy aging."

https://www.sciencedaily.com/releases/2018/06/180627160453.htm

Leg exercise is critical to brain and nervous system health

In a new take on the exercise truism 'use it, or lose it,' researchers show neurological health is an interactive relationship with our muscles and our world

May 23, 2018

Science Daily/Frontiers

New research shows that using the legs, particularly in weight-bearing exercise, sends signals to the brain that are vital for the production of healthy neural cells. The groundbreaking study fundamentally alters brain and nervous system medicine -- giving doctors new clues as to why patients with motor neuron disease, multiple sclerosis, spinal muscular atrophy and other neurological diseases often rapidly decline when their movement becomes limited.

"Our study supports the notion that people who are unable to do load-bearing exercises -- such as patients who are bed-ridden, or even astronauts on extended travel -- not only lose muscle mass, but their body chemistry is altered at the cellular level and even their nervous system is adversely impacted," says Dr. Raffaella Adami from the Università degli Studi di Milano, Italy.

The study involved restricting mice from using their hind legs, but not their front legs, over a period of 28 days. The mice continued to eat and groom normally and did not exhibit stress. At the end of the trial, the researchers examined an area of the brain called the sub-ventricular zone, which in many mammals has the role of maintaining nerve cell health. It is also the area where neural stem cells produce new neurons.

Limiting physical activity decreased the number of neural stem cells by 70 percent compared to a control group of mice, which were allowed to roam. Furthermore, both neurons and oligodendrocytes -- specialized cells that support and insulate nerve cells -- didn't fully mature when exercise was severely reduced.

The research shows that using the legs, particularly in weight-bearing exercise, sends signals to the brain that are vital for the production of healthy neural cells, essential for the brain and nervous system. Cutting back on exercise makes it difficult for the body to produce new nerve cells -- some of the very building blocks that allow us to handle stress and adapt to challenge in our lives.

"It is no accident that we are meant to be active: to walk, run, crouch to sit, and use our leg muscles to lift things," says Adami. "Neurological health is not a one-way street with the brain telling the muscles 'lift,' 'walk,' and so on."

The researchers gained more insight by analyzing individual cells. They found that restricting exercise lowers the amount of oxygen in the body, which creates an anaerobic environment and alters metabolism. Reducing exercise also seems to impact two genes, one of which, CDK5Rap1, is very important for the health of mitochondria -- the cellular powerhouse that releases energy the body can then use. This represents another feedback loop.

These results shed light on several important health issues, ranging from concerns about cardio-vascular impacts as a result of sedentary lifestyles to insight into devastating diseases, such as spinal muscular atrophy (SMA), multiple sclerosis, and motor neuron disease, among others.

"I have been interested in neurological diseases since 2004," says co-author Dr. Daniele Bottai, also from the Università degli Studi di Milano. "The question I asked myself was: is the outcome of these diseases due exclusively to the lesions that form on the spinal cord in the case of spinal cord injury and genetic mutation in the case of SMA, or is the lower capacity for movement the critical factor that exacerbates the disease?"

This research demonstrates the critical role of movement and has a range of potential implications. For example, missions to send astronauts into space for months or even years should keep in mind that gravity and load-bearing exercise play an important role in maintaining human health, say the researchers.

"One could say our health is grounded on Earth in ways we are just beginning to understand," concludes Bottai.

https://www.sciencedaily.com/releases/2018/05/180523080214.htm

Children are as fit as endurance athletes

April 24, 2018

Science Daily/Frontiers

Researchers discover how young children seem to run around all day without getting tired: their muscles resist fatigue and recover in the same way as elite endurance athletes. The study, which compared energy output and post-exercise recovery rates of young boys, untrained adults and endurance athletes, can be used to develop athletic potential in children and improve our knowledge of how disease risk, such as diabetes, increases as our bodies change from childhood to adulthood.

Children not only have fatigue-resistant muscles, but recover very quickly from high-intensity exercise -- even faster than well-trained adult endurance athletes. This is the finding of new research published in open-access journal Frontiers in Physiology, which compared the energy output and post-exercise recovery rates of young boys, untrained adults and endurance athletes. The research could help develop athletic potential in children as well as improve our understanding of how our bodies change from childhood to adulthood -- including how these processes contribute to the risk of diseases such as diabetes.

"During many physical tasks, children might tire earlier than adults because they have limited cardiovascular capability, tend to adopt less-efficient movement patterns and need to take more steps to move a given distance. Our research shows children have overcome some of these limitations through the development of fatigue-resistant muscles and the ability to recover very quickly from high-intensity exercise," say Sébastien Ratel, Associate Professor in Exercise Physiology who completed this study at the Université Clermont Auvergne, France, and co-author Anthony Blazevich, Professor in Biomechanics at Edith Cowan University, Australia.

Previous research has shown that children do not tire as quickly as untrained adults during physical tasks. Ratel and Blazevich suggested the energy profiles of children could be comparable to endurance athletes, but there was no evidence to prove this until now.

The researchers asked three different groups -- 8-12 year-old boys and adults of two different fitness levels -- to perform cycling tasks. The boys and untrained adults were not participants in regular vigorous physical activity. In contrast the last group, the endurance athletes, were national-level competitors at triathlons or long-distance running and cycling.

Each group was assessed for the body's two different ways of producing energy. The first, aerobic, uses oxygen from the blood. The second, anaerobic, doesn't use oxygen and produces acidosis and lactate (often known by the incorrect term, lactic acid), which may cause muscle fatigue. The participants' heart-rate, oxygen levels and lactate-removal rates were checked after the cycling tasks to see how quickly they recovered.

In all tests, the children outperformed the untrained adults.

"We found the children used more of their aerobic metabolism and were therefore less tired during the high-intensity physical activities," says Ratel. "They also recovered very quickly -- even faster than the well-trained adult endurance athletes -- as demonstrated by their faster heart-rate recovery and ability to remove blood lactate."

"This may explain why children seem to have the ability to play and play and play, long after adults have become tired."

Ratel and Blazevich explain the significance of their findings. "Many parents ask about the best way to develop their child's athletic potential. Our study shows that muscle endurance is often very good in children, so it might be better to focus on other areas of fitness such as their sports technique, sprint speed or muscle strength. This may help to optimize physical training in children, so that they perform better and enjoy sports more."

Ratel continues, "With the rise in diseases related to physical inactivity, it is helpful to understand the physiological changes with growth that might contribute to the risk of disease. Our research indicates that aerobic fitness, at least at the muscle level, decreases significantly as children move into adulthood -- which is around the time increases in diseases such as diabetes occur.

"It will be interesting in future research to determine whether the muscular changes we have observed are directly related to disease risk. At least, our results might provide motivation for practitioners to maintain muscle fitness as children grow up; it seems that being a child might be healthy for us."

https://www.sciencedaily.com/releases/2018/04/180424083907.htm

It's not your fitness tracker -- it's you

When it comes to measuring fitness, no one gets it right

April 12, 2018

Science Daily/University of Southern California

An international study reveals that no one defines physical activity the same way when they are asked to report how much they exercise. The findings are a caution for researchers trying to make cross-cultural comparisons about exercise.

An American, a Brit and a Dutch guy go for a walk. That may sound like the beginning of a joke, but it's actually the end of a USC-led study that could impact future research on physical activity.

With the help of fitness-tracking devices, an international team of scientists studied how physically active people consider themselves to be, versus how physically active they really are.

The research has revealed that no one gets it right. The American responses suggest they are as active as the Dutch or the English. Older people think they are as active as young people. In reality, though, Americans are much less active than the Europeans and older people are less active than the young.

Does this mean Americans are liars about their physical activity, or the Dutch and the English humbly underestimate theirs?

"It means people in different countries or at different age groups can have vastly different interpretations of the same survey questions," says Arie Kapteyn, the study's lead author and executive director of the Center for Economic and Social Research at the USC Dornsife College of Letters, Arts and Sciences.

Kapteyn believes the differences in fitness perceptions are driven by cultural and environmental differences.

For instance, Americans are largely dependent on cars while the Dutch frequently walk or ride bicycles to work and for simple errands, Kapteyn says.

The study was published on April 11 in the Journal of Epidemiology & Community Health.

Perception vs. reality

For the study, the scientists tracked 540 participants from the United States, 748 people from the Netherlands and 254 from England.

Men and women in the study, ages 18 and up, were asked in a survey to report their physical activity on a five-point scale, ranging from inactive to very active. They also wore a fitness-tracking device on their wrist (an accelerometer) so that scientists could measure their actual physical activity over a seven-day period.

The researchers found that the Dutch and English were slightly more likely to rate themselves toward the "moderate" center of the scale, while Americans tended to rate themselves at the extreme ends of the scale, either as "very active" or "inactive." But overall, the differences in how people from all three countries self-reported their physical activity was modest or non-existent.

The wearable devices revealed hard truths: Americans were much less physically active than both the Dutch and English. In fact, the percentage of Americans in the inactive category was nearly twice as large as the percentage of Dutch participants.

Reality bytes by age group

A comparison of fitness tracker data by age group reveals that people in all three countries are generally less active as they get older. That said, inactivity appeared more widespread among older Americans than participants in the other countries: 60 percent of Americans were inactive, compared to 42 percent of the Dutch and 32 percent of the English.

The researchers found that, in all three countries, the disparities between perceived and real activity levels were greatest among participants who reported that they were either "very active" or "very inactive."

"Individuals in different age groups simply have different standards of what it means to be physically active," said Kapteyn. "They adjust their standards based on their circumstances, including their age."

Kapteyn says that since physical activity is so central to a healthy life, accurate measurements are important to science. The findings indicate that scientists should proceed with caution when interpreting and comparing the results of international fitness studies that have utilized standardized questionnaires.

"When you rely on self-reported data, you're not only relying on people to share a common understanding of survey terms, but to accurately remember the physical activity that they report," says Kapteyn. "With the wide availability of low-cost activity tracking devices, we have the potential to make future studies more reliable."

https://www.sciencedaily.com/releases/2018/04/180412102746.htm

Brain differences in athletes playing contact vs. non-contact sports

April 5, 2018

Science Daily/Indiana University

A study has found differences in the brains of athletes who participate in contact sports compared to those who participate in non-contact sports.

The differences were observed as both groups were given a simple visual task. The results could suggest that a history of minor but repeated blows to the head can result in compensatory changes to the brain as it relates to eye movement function. Or it could show how the hundreds of hours that contact sport players spend on eye-hand coordination skills leads to a reorganization of the brain in the areas dedicated to eye movements.

While more research is needed, senior author Nicholas Port said the findings contribute important information to research on subconcussive blows -- or "microconcussions" -- that are common in sports such as football, soccer, ice hockey, snowboarding and skiing. Interest in subconcussions has grown significantly in recent years as the long- and short-term risks of concussions -- or mild traumatic brain injury -- have become more widely known and understood.

"The verdict is still out on the seriousness of subconcussions, but we've got to learn more since we're seeing a real difference between people who participate in sports with higher risk for these impacts," said Port, an associate professor in the IU School of Optometry. "It's imperative to learn whether these impacts have an actual effect on cognitive function -- as well as how much exposure is too much."

To conduct the study, Port and researchers in the IU Bloomington Department of Psychological and Brain Sciences scanned the brains of 21 football players and 19 cross-country runners using fMRI technology.

The researchers focused on these sports because football is a physical game in which small but repeated blows to the head are common, whereas cross-country is extremely low risk for such impacts. The contact sport players did not have a history of concussion, but these sports are known to lead to repeat subconcussive blows.

The researchers also scanned the brains of 11 non-college-level athletes from socioeconomic backgrounds similar to the football players to ensure their scan results were not rooted in factors unrelated to their sport.

The differences in football players' versus cross-country runners' brains were specifically seen in regions of the brain responsible for visual processing. These regions were much more active in football players versus cross-country runners or volunteers who did not play college sports.

"We focused on these brain regions because physicians and trainers regularly encounter large deficits in players' ability to smoothly track a moving point with their eyes after suffering an acute concussion," Port said.

Although there were clear differences between the brains of the football players and the cross-country runners, Port said interpretation of the study's results is challenging.

"Everyone from musicians to taxi drivers has differences in brain activity related to their specific skills," he said. "The differences in this study may reflect a lifetime exposure of subconcussive blows to the head, or they could simply be the result of playing a visually demanding sport where you're constantly using your hands and tracking the ball."

The ideal way to find the root cause of these differences would be a similar analysis using only football players, he said. The next generation of wearable accelerometers to measure physical impact during play will greatly enhance researchers' ability to confidently sort players of the same sport into groups based on exposure to subconcussions.

https://www.sciencedaily.com/releases/2018/04/180405120319.htm

Stopping exercise can increase symptoms of depression

March 22, 2018

Science Daily/University of Adelaide

PhD student Julie Morgan from the University of Adelaide's Discipline of Psychiatry has reviewed the results of earlier studies that examined the effects of stopping exercise in regularly active adults.

The results of her review are now published online ahead of print in the Journal of Affective Disorders.

"Adequate physical activity and exercise are important for both physical and mental health," says Ms Morgan.

"Current public health guidelines recommend being active on most if not all days of the week. At least 150 minutes of moderate intensity exercise a week is recommended to maintain health and prevent depression, or 75 minutes of vigorous intensity exercise for added health benefits.

"An extensive body of clinical evidence shows that regular exercise can reduce and treat depression. However, there is limited research into what happens with depressive symptoms when exercise is stopped," she says.

Ms Morgan reviewed studies that investigated the cessation of exercise in 152 adults. They had each undertaken at least 30 minutes of exercise, three times a week, for a minimum of three months.

"In some cases, ceasing this amount of exercise induced significant increases in depressive symptoms after just three days," says Professor Bernhard Baune, Head of Psychiatry at the University of Adelaide and senior author on the paper.

"Other studies showed that people's depressive symptoms increased after the first one or two weeks, which is still quite soon after stopping their exercise."

Professor Baune says the depressive symptoms arising from stopping exercise occurred in the absence of the typical biological markers commonly involved with depressive symptoms.

"This suggests some kind of novel effect in these cases, although we should add some caution here, as the number of people included in the studies we examined was small. Such findings would need to be replicated in additional trials," he says.

Professor Baune says the lack of research in this specific area points to the need for further studies, to help better understand the way in which stopping exercise affects depressive symptoms.

"For now, it is important that people understand the potential impact on their mental well-being when they suddenly cease regular exercise," he says.

https://www.sciencedaily.com/releases/2018/03/180322112720.htm

Poor fitness linked to weaker brain fiber, higher dementia risk

February 14, 2018

Science Daily/UT Southwestern Medical Center

Scientists have more evidence that exercise improves brain health and could be a lifesaving ingredient that prevents Alzheimer's disease.

In particular, a new study from UT Southwestern's O'Donnell Brain Institute suggests that the lower the fitness level, the faster the deterioration of vital nerve fibers in the brain. This deterioration results in cognitive decline, including memory issues characteristic of dementia patients.

"This research supports the hypothesis that improving people's fitness may improve their brain health and slow down the aging process," said Dr. Kan Ding, a neurologist from the Peter O'Donnell Jr. Brain Institute who authored the study.

White matter

The study published in the Journal of Alzheimer's Disease focused on a type of brain tissue called white matter, which is composed of millions of bundles of nerve fibers used by neurons to communicate across the brain.

Dr. Ding's team enrolled older patients at high risk to develop Alzheimer's disease who have early signs of memory loss, or mild cognitive impairment (MCI). The researchers determined that lower fitness levels were associated with weaker white matter, which in turn correlated with lower brain function.

Distinctive tactics

Unlike previous studies that relied on study participants to assess their own fitness, the new research objectively measured cardiorespiratory fitness with a scientific formula called maximal oxygen uptake. Scientists also used brain imaging to measure the functionality of each patient's white matter.

Patients were then given memory and other cognitive tests to measure brain function, allowing scientists to establish strong correlations between exercise, brain health, and cognition.

Lingering mysteries

The study adds to a growing body of evidence pointing to a simple yet crucial mandate for human health: Exercise regularly.

However, the study leaves plenty of unanswered questions about how fitness and Alzheimer's disease are intertwined. For instance, what fitness level is needed to notably reduce the risk of dementia? Is it too late to intervene when patients begin showing symptoms?

Some of these topics are already being researched through a five-year national clinical trial led by the O'Donnell Brain Institute.

The trial, which includes six medical centers across the country, aims to determine whether regular aerobic exercise and taking specific medications to reduce high blood pressure and cholesterol levels can help preserve brain function. It involves more than 600 older adults at high risk to develop Alzheimer's disease.

"Evidence suggests that what is bad for your heart is bad for your brain. We need studies like this to find out how the two are intertwined and hopefully find the right formula to help prevent Alzheimer's disease," said Dr. Rong Zhang of UT Southwestern, who oversees the clinical trial and is Director of the Cerebrovascular Laboratory in the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas, where the Dallas arm of the study is being carried out.

Prior findings

The research builds upon prior investigations linking healthy lifestyles to better brain function, including a 2013 study from Dr. Zhang's team that found neuronal messages are more efficiently relayed in the brains of older adults who exercise.

In addition, other teams at the O'Donnell Brain Institute are designing tests for the early detection of patients who will develop dementia, and seeking methods to slow or stop the spread of toxic proteins associated with the disease such as beta-amyloid and tau, which are blamed for destroying certain groups of neurons in the brain.

"A lot of work remains to better understand and treat dementia," said Dr. Ding, Assistant Professor of Neurology & Neurotherapeutics. "But, eventually, the hope is that our studies will convince people to exercise more."

https://www.sciencedaily.com/releases/2018/02/180214181952.htm