Exercise may protect brain volume by keeping insulin and BMI levels low

April 13, 2022

Science Daily/American Academy of Neurology

Studies have shown that exercise helps protect brain cells. A new study looking at the mechanisms involved in this relationship suggests that the role exercise plays in maintaining insulin and body mass index levels may help protect brain volume and thus help stave off dementia. The research is published in the April 13, 2022, online issue of Neurology®, the medical journal of the American Academy of Neurology.

"These results may help us to understand how physical activity affects brain health, which may guide us in developing strategies to prevent or delay age-related decline in memory and thinking skills," said study author Géraldine Poisnel, PhD, of Inserm Research Center in Caen, France. "Older adults who are physically active gain cardiovascular benefits, which may result in greater structural brain integrity."

In contrast, researchers found that the relationship between exercise and the metabolism of glucose in the brain was not affected by insulin or body mass index (BMI) levels. Reduced glucose metabolism in the brain can been seen in people with dementia.

The study involved 134 people with an average age of 69 who had no memory problems. The people filled out surveys about their physical activity over the past year. They had brain scans to measure volume and glucose metabolism. Information was gathered on BMI and insulin levels as well as cholesterol, blood pressure and other factors.

People with the most physical activity had a higher total volume of grey matter in their brains than people with the least amount of physical activity, with an average of about 550,000 cubic millimeters (mm³) compared to about 540,000 mm³. When researchers looked only at areas of the brain affected by Alzheimer's disease, they found the same results.

Those with the most activity also had a higher average rate of glucose metabolism in the brain than those with the least amount of activity.

Higher physical activity was not associated with how much amyloid plaque people had in their brains. Amyloid plaque is a marker for Alzheimer's disease.

Poisnel said more research is needed to understand the mechanisms behind these relationships. "Maintaining a lower BMI through physical activity could help prevent disturbed insulin metabolism that is often seen in aging, thus promoting brain health," Poisnel said.

The study does not prove that exercise protects brain volume. It only shows an association.

A limitation of the study is that people reported their own physical activity, so they may not remember it accurately.

https://www.sciencedaily.com/releases/2022/04/220413161810.htm

Intense exercise while dieting may reduce cravings for fatty food

April 21, 2022

Science Daily/Washington State University

In a study that offers hope for human dieters, rats on a 30-day diet who exercised intensely resisted cues for favored, high-fat food pellets.

The experiment was designed to test resistance to the phenomenon known as "incubation of craving," meaning the longer a desired substance is denied, the harder it is to ignore signals for it. The findings suggest that exercise modulated how hard the rats were willing to work for cues associated with the pellets, reflecting how much they craved them.

While more research needs to be done, the study may indicate that exercise can shore up restraint when it comes to certain foods, said Travis Brown, a Washington State University physiology and neuroscience researcher.

"A really important part of maintaining a diet is to have some brain power -- the ability to say 'no, I may be craving that, but I'm going to abstain,'" said Brown, corresponding author on the study published in the journal Obesity. "Exercise could not only be beneficial physically for weight loss but also mentally to gain control over cravings for unhealthy foods."

In the experiment, Brown and colleagues from WSU and University of Wyoming put 28 rats through a training with a lever that when pressed, turned on a light and made a tone before dispensing a high-fat pellet. After the training period, they tested to see how many times the rats would press the lever just to get the light and tone cue.

The researchers then split the rats into two groups: one underwent a regime of high-intensity treadmill running; the other had no additional exercise outside of their regular activity. Both sets of rats were denied access to the high-fat pellets for 30 days. At the end of that period, the researchers gave the rats access to the levers that once dispensed the pellets again, but this time when the levers were pressed, they only gave the light and tone cue. The animals that did not get exercise pressed the levers significantly more than rats that had exercised, indicating that exercise lessened the craving for the pellets.

In future studies, the research team plans to investigate the effect of different levels of exercise on this type of craving as well as how exactly exercise works in the brain to curb the desire for unhealthy foods.

While this study is novel, Brown said it builds on the work of Jeff Grimm at Western Washington University who led the team that first defined the term "incubation of craving" and has studied other ways to subvert it. Brown also credited Marilyn Carroll-Santi's research at University of Minnesota showing that exercise can blunt cravings for cocaine.

It is still an unsettled research question as to whether food can be addictive in the same way as drugs. Not all foods appear to have an addictive effect; as Brown pointed out, "no one binge eats broccoli." However, people do seem to respond to cues, such as fast-food ads, encouraging them to eat foods high in fat or sugar, and those cues may be harder to resist the longer they diet.

The ability to disregard these signals may be yet another way exercise improves health, Brown said.

"Exercise is beneficial from a number of perspectives: it helps with cardiac disease, obesity and diabetes; it might also help with the ability to avoid some of these maladaptive foods," he said. "We're always looking for this magic pill in some ways, and exercise is right in front of us with all these benefits."

https://www.sciencedaily.com/releases/2022/04/220421094049.htm

Exercise may reduce depression symptoms, boost effects of therapy

March 30, 2022

Science Daily/Iowa State University

Exercising for half an hour may reduce symptoms of depression for at least 75 minutes post-workout and amplify the benefits of therapy, according to two new studies led by researchers at Iowa State University.

"A lot of previous research on the effects of exercise on mental health, in general, have used very broad measures of wellbeing. What we were interested in, specifically, is: how does acute exercise -- that is, one session of exercise in a day -- influence the primary symptoms of depression," said Jacob Meyer, a professor of kinesiology at ISU and the lead-author of both publications.

For the first study, the researchers recruited 30 adults who were experiencing major depressive episodes. The participants filled out electronic surveys immediately before, half-way-through and after a 30-minute session of either moderate-intensity cycling or sitting, and then 25-, 50- and 75-minutes post-workout. Those who cycled during the first lab visit came back a week later to run through the experiment again with 30-minutes of sitting, and vice versa.

Each survey included standard questions and scales used to measure symptoms of depression and several cognitive tasks, including the Stroop test; participants responded to the color of a particular font rather than the word itself (e.g., indicating red when they saw the word 'blue' in red ink).

The researchers then used the survey data to track any changes in three characteristics of major depressive disorder: depressed mood state (e.g., sad, discouraged, gloomy), anhedonia (i.e., difficulty experiencing pleasure from activities previously enjoyed) and decreased cognitive function (e.g., difficulty thinking, juggling multiple pieces of information at once).

During the cycling experiment, participants' depressed mood state improved over the 30 minutes of exercise and consistently up to 75 minutes afterward. The improvement to anhedonia started to drop off at 75 minutes post-exercise, but still was better than the participants' levels of anhedonia in the group that did not exercise.

As for cognitive function, participants who cycled were faster on the Stroop test mid-exercise but relatively slower 25- and 50-minutes post-exercise compared to participants in the resting group. Meyer said more research is needed to understand the variation.

"The cool thing is these benefits to depressed mood state and anhedonia could last beyond 75 minutes. We would need to do a longer study to determine when they start to wane, but the results suggest a window of time post-exercise when it may be easier or more effective for someone with depression to do something psychologically or cognitively demanding," said Meyer.

He said that could include giving a presentation, taking a test -- or going to therapy.

"Can we synergize the short-term benefits we know that happen with exercise and the clear long-term benefits with therapy to deliver the most effective overall intervention?" asked Meyer.

As part of the effort to answer that question, Meyer and his research team conducted a separate pilot study.

Half of the ten participants exercised on their own (e.g., cycled, jogged, walked) for 30 minutes at a pace they considered moderate intensity, which the researchers also verified with Fitbit data, before signing into an hour of virtual, cognitive behavior therapy each week. The other participants simply continued in their day-to-day activities prior to their therapy sessions.

At the end of the eight-week intervention program, participants in both groups showed improvements, but those who exercised before talking with a therapist had more pronounced reductions in symptoms of depression.

The researchers said the results indicate exercise could help amplify the benefits of therapy for adults with depression.

"With such a small group, we did not perform formal statistical testing, but the results are promising," said Meyer. "Overall, the pilot study showed people were interested and would stick with the combined approach, and that exercise seemed to have some effects on depression and a couple of the mechanisms of therapy."

One of those mechanisms relates to the relationship between a client and therapist. If someone feels a connection with their therapist, Meyer said, there's a higher chance they'll continue going to therapy and the sessions likely will have greater impact.

In the pilot study, participants who exercised before the cognitive behavior therapy session reported a quicker and stronger connection with their therapists. The researchers said the findings suggest exercise may be priming or "fertilizing" the brain to engage with more emotionally challenging work that can happen during therapy.

The researchers said they hope to expand on the innovative studies in the coming years to better understand how exercise could be incorporated into an effective treatment or intervention for people experiencing chronic depression.

https://www.sciencedaily.com/releases/2022/03/220330101735.htm

Exercise holds even more heart health benefits for people with stress-related conditions

Study underscores the brain’s role in deriving cardiovascular benefits from physical activity

March 24, 2022

Science Daily/American College of Cardiology

Regular physical activity had nearly doubled the cardiovascular benefit in individuals with depression or anxiety, compared with individuals without these diagnoses, according to a study presented at the American College of Cardiology's 71st Annual Scientific Session.

The research findings add to mounting evidence that exercise improves cardiovascular health by helping to activate parts of the brain that counteract stress. Overall, the study found that people who achieved the recommended amount of physical activity per week were 17% less likely to suffer a major adverse cardiovascular event than those who exercised less. These benefits were significantly greater in those with anxiety or depression, who had a 22% risk reduction vs. a 10% risk reduction in those without either condition.

"The effect of physical activity on the brain's stress response may be particularly relevant in those with stress-related psychiatric conditions," said Hadil Zureigat, MD, postdoctoral clinical research fellow at Massachusetts General Hospital and the study's lead author. "This is not to suggest that exercise is only effective in those with depression or anxiety, but we found that these patients seem to derive a greater cardiovascular benefit from physical activity."

Rates of both depression and anxiety have risen during the COVID-19 pandemic, and heart disease remains the leading cause of death in the U.S. The study findings underscore the important role of exercise in maintaining heart health and reducing stress, according to the researchers.

For the study, researchers analyzed health records of more than 50,000 patients in the Massachusetts General Brigham Biobank database. Just over 4,000 of the patients had suffered a major adverse cardiovascular event, which included experiencing a heart attack, having chest pain caused by a blocked artery or undergoing a procedure to open a blocked artery in the heart.

Researchers first assessed the rates of major coronary events among patients who reported in a questionnaire that they exercise at least 500 metabolic equivalent (MET) minutes per week -- aligning with the ACC and American Heart Association primary prevention guideline recommendation of at least 150 minutes of moderate intensity exercise per week -- with those who exercise less. MET-minutes are a unit of exercise that represents the amount of energy expended during various activities. The analysis revealed that people who got at least 500 MET-minutes or more per week were 17% less likely to suffer an adverse cardiovascular event.

They then analyzed how this pattern played out among patients who had a diagnosis of depression or anxiety compared with those who did not have depression or anxiety. This second analysis revealed that patients with depression derived more than double the benefit from exercise in terms of reduced cardiovascular risk compared with people who did not have depression. A similar benefit of exercise was found for patients with anxiety.

The research expands upon previous studies by the research team that used brain imaging to determine how exercise improves cardiovascular health by helping to keep the brain's stress response in check. Individuals with depression or anxiety have higher stress-related neural activity and a higher risk of cardiovascular disease.

"When one thinks about physical activity decreasing cardiovascular risk, one doesn't usually think of the brain," Zureigat said. "Our research emphasizes the importance of the stress-related neural mechanisms by which physical activity acts to reduce cardiovascular risk."

Even though the study used 500 MET-minutes as a cutoff for the analysis, researchers noted that previous studies show people can reduce their heart disease risk even if they do not achieve the recommended amount of physical activity. Even a little bit of regular physical activity can make a difference in terms of cardiovascular risk.

"Any amount of exercise is helpful, particularly for those with depression or anxiety," Zureigat said. "Not only will physical activity help them feel better, but they will also potently reduce their risk of cardiovascular disease. It can be hard to make the transition, but once achieved, physical activity allows those with these common chronic stress-related psychiatric conditions to hit two birds with one stone."

https://www.sciencedaily.com/releases/2022/03/220324104415.htm

The secret to staying young: New research highlights power of life long exercise to keep muscles healthy

March 21, 2022

Science Daily/The Physiological Society

Lifelong physical activity could protect against age-related loss of muscle mass and function, according to research published in The Journal of Physiology. Individuals aged 68 and above who were physically active throughout their life have healthier ageing muscle that has superior function and is more resistant to fatigue compared to inactive individuals, both young and old.

This is the first study to investigate muscle, stem cell and nerve activity in humans. The researchers from University of Copenhagen, Denmark, found that elderly individuals who keep physically active throughout their adult life, whether by taking part in resistance exercise, ball games, racket sports, swimming, cycling, running and/or rowing had a greater number of muscle stem cells, otherwise known as satellite cells in their muscle. These cells are important for muscle regeneration and long-term growth and protect against nerve decay.

46 male participants took part in the study. They were divided into three groups: young sedentary (15), elderly lifelong exercise (16) and elderly sedentary (15). They performed a heavy resistance exercise, sitting in a mechanical chair performing a knee extension movement to evaluate muscle function. The amount of force produced was measured. Blood samples were taken, and muscle biopsies were analysed from both legs. The researchers found elderly lifelong exercisers outperformed both the elderly and young sedentary adults.

Lead author, Casper Soendenbroe, University of Copenhagen, Denmark said:

"This is the first study in humans to find that lifelong exercise at a recreational level could delay some detrimental effects of ageing. Using muscle tissue biopsies, we've found positive effects of exercise on the general ageing population. This has been missing from the literature as previous studies have mostly focused on master athletes, which is a minority group. Our study is more representative of the general population aged 60 and above, as the average person is more likely to take part in a mixture of activities at a moderate level. That's why we wanted to explore the relation between satellite cell content and muscle health in recreationally active individuals. We can now use this as a biomarker to further investigate the link between exercise, ageing and muscle health."

"The single most important message from this study, is that even a little exercise seems to go a long way, when it comes to protecting against the age-related decline in muscle function. This is an encouraging finding which can hopefully spur more people to engage in an activity that they enjoy. We still have much to learn about the mechanisms and interactions between nerves and muscles and how these change as we age. Our research takes us one step closer."

It is worth noting that the study was only carried out in males and the average age was 73. As the effects of ageing on muscle health become more pronounced at 80+ years, follow up studies are needed to see if the benefits of lifelong exercise are maintained later in life. Further, investigation on recreational activity and muscle health need to be carried out in females.

https://www.sciencedaily.com/releases/2022/03/220321103818.htm

Exercise may treat long COVID-induced diabetes, depression

March 11, 2022

Science Daily/Pennington Biomedical Research Center

While no medically recognized treatment exists for Long COVID, exercise may break the vicious cycle of inflammation that can lead to developing diabetes and depression months after a person recovers from the virus.

"We know that Long COVID causes depression, and we know that it can increase blood glucose levels to the point where people develop diabetic ketoacidosis, a potentially life-threatening condition common among people with type 1 diabetes," said Candida Rebello, Ph.D., a research scientist at Pennington Biomedical Research Center. "Exercise can help. Exercise takes care of the inflammation that leads to elevated blood glucose and the development and progression of diabetes and clinical depression."

It's unclear how many people suffer from Long COVID. But estimates range from 15 percent to 80 percent of the people infected. Based on those figures, it's possible that as many as 1 million of Louisiana's residents suffer from Long COVID.

Long COVID causes what the Centers for Disease Control describes as "a constellation of other debilitating symptoms" including brain fog, muscle pain, and fatigue that can last for months after a person recovers from the initial infection.

"For example, a person may not get very sick from COVID-19, but six months later, long after the cough or fever is gone, they develop diabetes,' Dr. Rebello said.

One solution is exercise. Dr. Rebello and her co-authors describe their hypothesis in "Exercise as a Moderator of Persistent Neuroendocrine Symptoms of COVID-19," published in the journal Exercise and Sport Sciences Reviews.

"You don't have to run a mile or even walk a mile at a brisk pace," Dr. Rebello said. "Walking slowly is also exercising. Ideally, you would do a 30-minute session of exercise. But if you can only do 15 minutes at a time, try to do two 15-minute sessions. If you can only walk 15 minutes once a day, do that. The important thing is to try. It doesn't matter where you begin. You can gradually build up to the recommended level of exercise."

"We know that physical activity is a key component to a healthy life. This research shows that exercise can be used to break the chain reaction of inflammation that leads to high blood sugar levels, and then to the development or progression of type 2 diabetes," said Pennington Biomedical Executive Director John Kirwan, Ph.D., who is also a co-author of the paper.

https://www.sciencedaily.com/releases/2022/03/220311095317.htm

Physical activity may protect your brain as you age

Even just a few more steps a day benefits cognitive function

March 8, 2022

Science Daily/University of Georgia

We all know we should exercise and eat healthy. But doing that isn't just good for maintaining your figure as you age.

New research from the University of Georgia shows that physical activity could help protect your cognitive abilities as you age. And it doesn't have to be intense exercise to make an impact.

"This finding isn't saying, 'If you're older, you need to go out there and start running marathons,'" said Marissa Gogniat, lead author of the study and a recent doctoral graduate in psychology from the Franklin College of Arts and Sciences. "This is saying if you get more steps, if you're moving around your environment a little bit more, that can be helpful to your brain health and keep you more independent as you age."

Exercise improves brain function 

Published in Sport Sciences for Health, the study followed 51 older adults, tracking their physical activity and fitness measurements. The participants performed tests specifically designed to measure cognitive functioning and underwent MRIs to assess brain functioning.

They also wore a device that measured the intensity of the wearer's physical activity, number of steps taken and distance covered. The researchers assessed fitness through a six-minute walking test, during which participants walked as quickly as they could to cover the most distance possible within the time limit.

"We've always been told it's good to exercise, but I think this is some evidence that exercise can actually change your brain," Gogniat said. "And that impacts the way you're able to function in your daily life."

Brain networks improve with physical activity

The brain is made up of a bunch of distinct networks. Those networks are in constant communication, sending information to each other.

But different parts of the brain are active at different times. The network that is active when the body is at rest, for example, flips off when a person starts trying to complete a task. At that time, another network kicks on.

While one of these networks is active, the other should be shut off. If it's not, that's a sign that a person's brain isn't functioning as well as it should be.

These networks are the key to being able to perform basic tasks in daily life, such as remembering important information and exhibiting self-control. But as people age, these tasks often become more difficult.

This study was the first to examine how these networks interact with physical activity and fitness to impact how the brain functions.

"This paper is exciting because it gives us some evidence that when people whose brain networks aren't functioning optimally engage in physical activity, we see improvement in their executive function and their independence," Gogniat said. "We're not saying you need to radically change your life.

"Maybe just take the stairs on the way to work. Stand up and walk around a little bit more. That's where you get the most bang for your buck, not crazy, high-intensity exercise."

https://www.sciencedaily.com/releases/2022/03/220308155637.htm

Physical fitness linked to lower risk of Alzheimer’s disease

February 28, 2022

Science Daily/American Academy of Neurology

People who are more physically fit are less likely to develop Alzheimer's disease than people who are less physically fit, according to a preliminary study released today, February 27, 2022, that will be presented at the American Academy of Neurology's 74th Annual Meeting being held in person in Seattle, April 2 to 7, 2022 and virtually, April 24 to 26, 2022.

"One exciting finding of this study is that as people's fitness improved, their risk of Alzheimer's disease decreased -- it was not an all-or-nothing proposition," said study author Edward Zamrini, MD, of the Washington VA Medical Center in Washington, D.C., and a member of the American Academy of Neurology. "So people can work toward making incremental changes and improvements in their physical fitness and hopefully that will be associated with a related decrease in their risk of Alzheimer's years later."

The study involved 649,605 military veterans in the Veterans Health Administration database with an average age of 61 who were followed for an average of nine years. They did not have Alzheimer's disease at the start of the study.

Researchers determined participants' cardiorespiratory fitness. Cardiorespiratory fitness is a measure of how well your body transports oxygen to your muscles, and how well your muscles are able to absorb oxygen during exercise.

The participants were divided into five groups, from least fit to most fit. Fitness levels were determined by how well participants did on a treadmill test. This test measures exercise capacity, the highest amount of physical exertion a person can sustain. For people who are middle-aged and older, the highest level of fitness can be achieved by walking briskly most days of the week, for two and a half hours or more per week.

The group with the lowest level of fitness developed Alzheimer's at a rate of 9.5 cases per 1,000 person-years, compared to 6.4 cases per 1,000 person-years for the most fit group. Person-years take into account the number of people in a study as well as the amount of time spent in the study. The case rate decreased as the level of fitness increased, with a rate of 8.5 for the second least fit group, 7.4 for the middle group and 7.2 for the second most fit group.

When researchers adjusted for other factors that could affect risk of Alzheimer's disease, they found that the people in the most fit group were 33% less likely to develop Alzheimer's disease than those in the least fit group. The second most fit group was 26% less likely to develop the disease, while the middle group was 20% less likely and those in the second least fit group were 13% less likely to develop the disease than those in the least fit group.

"The idea that you can reduce your risk for Alzheimer's disease by simply increasing your activity is very promising, especially since there are no adequate treatments to prevent or stop the progression of the disease," Zamrini said. "We hope to develop a simple scale that can be individualized so people can see the benefits that even incremental improvements in fitness can deliver."

A limitation of the study was participants were mostly white men so results may not be generalizable to other populations.

The study was supported by the National Institute on Aging, the National Institutes of Health, the U.S. Department of Veterans Affairs, the Washington D.C. VA Medical Center and George Washington University.

https://www.sciencedaily.com/releases/2022/02/220228125736.htm

Exercise can help older adults retain their memories

Pooling data from dozens of experiments let researchers show whose brains benefit the most from exercise

February 17, 2022

Science Daily/University of Pittsburgh

Conducting a meta-analysis of 3,000 patients over 36 studies (carefully vetted from more than 1,200 studies in all), psychologists were able to find that specific exercise helps episodic memory -- 3 times a week for 4 months, with greater improvements among those who are age 55 to 68 years.

We all know exercise is good for us, but that still leaves plenty of questions. How much exercise? Who benefits the most? And when in our lives? New research led by University of Pittsburgh psychologists pools data from dozens of studies to answer these questions, showing that older adults may be able to prevent declines in a certain kind of memory by sticking to regular exercise.

"Everyone always asks, 'How much should I be exercising? What's the bare minimum to see improvement?' " said lead author Sarah Aghjayan, a Clinical and Biological Health Psychology PhD student in the Kenneth P. Dietrich School of Arts and Sciences. "From our study, it seems like exercising about three times a week for at least four months is how much you need to reap the benefits in episodic memory."

Episodic memory is the kind that deals with events that happened to you in the past. It's also one of the first to decline with age. "I usually like to talk about the first time you got behind the wheel of a car," said Aghjayan. "So you might remember where you were, how old you were, who was in the passenger seat explaining things to you, that feeling of excitement."

Exercise that gets the heart pumping has shown promise in increasing brain health, and experiments in mice show that it improves memory -- but studies looking at the same link in humans have come out mixed.

Seeking clarity in the muddy waters of the scientific literature, the team pored over 1,279 studies, eventually narrowing them down to just 36 that met specific criteria. Then they used specialized software and no small number of Excel spreadsheets to transform the data info a form where the different studies could be directly compared.

That work paid off when they found that pooling together those 36 studies was enough to show that for older adults, exercise can indeed benefit their memory. The team, including Aghjayan's advisor Kirk Erickson in the Department of Psychology and other researchers from Pitt, Carnegie Mellon University and the University of Iowa, published their results in the journal Communications Medicine on Feb. 17.

Past analyses looking at connections between exercise and memory didn't find one, but Aghjayan and her team took several extra steps to give them the best chance of finding a link if one did exist. They limited their search to particular groups and age brackets as well as a specific kind of rigorous experimental setup. Another key was focusing specifically on episodic memory, which is supported by a part of the brain that's known to benefit from exercise.

"When we combine and merge all this data, it allows us to examine almost 3,000 participants," Aghjayan said. "Each individual study is very important: They all contribute to science in a meaningful way." Individual studies, however, may fail to find patterns that actually exist because of a lack of resources to run a big enough experiment. The studies individually couldn't find a link between exercise and memory -- it took looking at the whole body of research to bring the pattern into focus.

With that much larger pool of participants, the team was able to show a link between exercise and episodic memory, but also was able to start to answer more specific questions about who benefits and how.

"We found that there were greater improvements in memory among those who are age 55 to 68 years compared to those who are 69 to 85 years old -- so intervening earlier is better," Aghjayan said. The team also found the greatest effects of exercise in those who hadn't yet experienced any cognitive decline, and in studies where participants exercised consistently several times a week.

There are still questions left to be answered. The team's analysis couldn't answer how the intensity of exercise affects the memory benefits, and there's plenty to learn about the mechanism behind the link. But the implications for public health are clear: Exercise is an accessible way older adults can stave off memory declines, benefiting themselves, their caretakers and the healthcare system, Aghjayan said.

"You just need a good pair of walking shoes, and you can get out there and move your body."

https://www.sciencedaily.com/releases/2022/02/220217090610.htm

Your lunchtime walks in the summer could be making you less productive

Researchers find that a brief walk outside on a hot day impairs cognitive performance

February 28, 2022

Science Daily/University of Tsukuba

Studies have shown that being in a hot environment reduces cognitive performance, whereas a brief walk enhances cognition. But what happens when you go for a brief walk on a hot summer's day, as so many students and office workers do during lunch or an afternoon break? Turns out, you might be better off avoiding the heat.

In a study published this month in Building and Environment, researchers from the University of Tsukuba discovered that just 15 minutes of walking outside on a hot day impaired cognitive performance, and this was most striking in men who don't get enough sleep.

Those who work or study in urban heat islands, such as large cities in Japan, generally have the convenience of air-conditioning indoors over the summer months, which largely counters the negative impact of heat on learning and productivity. However, brief exposure to hot environments during commuting or breaks is inevitable, and whether such exposure affects cognition has not been known. "Previous experiments have used specialized climate chambers to test these effects. However, outdoor thermal environment differs significantly from indoor thermal environments in terms of radiation and wind," says senior author Professor Hiroyuki Kusaka. "Radiation and wind have significant effects on thermal perception. Therefore, in order to assess the effects of outdoor heat stress on cognitive performance, experiments should be conducted in real outdoor environments."

Researchers simulated a real-world scenario during the Japanese summer in which workers or students leave an air-conditioned indoor environment to walk or have a break in a hot outdoor urban environment. Ninety-six students completed a simple arithmetic test in an air-conditioned room before either staying indoors, walking outside, or resting outside for 15 minutes. They then returned indoors to complete a second arithmetic test, and any changes in performance were measured. Walking in a hot outdoor environment impaired cognitive performance; however, it was not simply the exposure to the hot environment that impaired cognition. Rather, it was the combination of walking and being outside in the summer heat that had impacted cognitive performance. Furthermore, this effect was more pronounced in people, specifically men, who were sleep deprived, having slept less than 5 hours.

"Japanese office workers and students, especially men, need to be aware of this situation as they work and study," says Kusaka. The team hopes that their findings will help guide ways to improve productivity and learning in workers and students in Japan, and perhaps even further afield as the impact of climate change moves to the forefront.

https://www.sciencedaily.com/releases/2022/02/220228114410.htm

Exercise can provide relief for dry, itchy eyes

Making time for regular exercise can make your eyes feel better

February 3, 2022

Science Daily/University of Waterloo

A team led by researchers from the University of Waterloo discovered that a significant increase in tear secretion and tear film stability after participating in aerobic exercise can be another remedy for relieving dry, itchy eyes.

Every time we blink, our eyes are covered in tear film -- an essential protective coating necessary for maintaining healthy ocular function. Healthy tear film comprises three layers-oil, water, and mucin-that work together to hydrate the ocular surface and protect against infection-causing irritants like dust or dirt.

When any part of the tear film becomes unstable, the ocular surface can develop dry spots, causing eye symptoms like itchiness or stinging and burning sensations.

"With so much of our activity tied to screen usage, dry eye symptoms are becoming increasingly common," said Heinz Otchere, a PhD candidate in vision science at Waterloo. "Instead of having to use eye drops or other alternative treatments, our study aimed to determine if remaining physically active can be an effective preventative measure against dryness."

Fifty-two participants were divided into two groups -- athlete and non-athlete -- to participate in an exercise session. Participants in the athlete group exercised at least five times per week, while non-athlete participants exercised no more than once per week. Researchers, which included experts from the University of Cape Coast in Ghana, performed visual examinations before and five minutes after each exercise session, where tear secretion and tear break-up time were assessed.

While participants in the athlete group showed the largest increase, Otchere says all participants experienced a meaningful boost in tear quantity and tear film stability after the exercise session.

"It can be challenging for people to regularly exercise when the demand is there to work increasingly longer hours in front of screens," Otchere said. "However, our findings show physical activity can be really important for not just our overall well-being, but for our ocular health too."

https://www.sciencedaily.com/releases/2022/02/220203083607.htm

Farther or faster? Both improve distance running performance

January 26, 2022

Science Daily/University of Jyväskylä

A study performed at the University of Jyväskylä compared two-week blocks of low-intensity training and high-intensity interval training in terms of performance and recovery. Both methods can improve endurance performance in recreational athletes after already two weeks when the training load is increased significantly from what the individual is accustomed to.

The weekly routine of distance runners typically consists of a permanent mix of low-intensity training and moderate- to high-intensity training. As an alternative, it has been suggested that block periodization with a more focused training target within a single period may have its advantages.

In a recent study, block periodization was examined with a setting where participants either added the volume of low-intensity training by 70% or performed 10 sessions of 6 x 3-min intervals (5 times/week) during the two-week block. A short block of low- or high-intensity interval training seemed to be an effective method for recreational athletes.

"Both groups improved their 3000 m running performance immediately after the block," explains doctoral researcher Olli-Pekka Nuuttila from the University of Jyväskylä. "The Interval group improved on average 13 seconds and the low-intensity group 11 seconds. The same trend was observed after the recovery week: the Interval group's time was on average 19 seconds faster compared to baseline and in the low-intensity group difference was 17 seconds. No statistically significant differences were observed between the groups."

Interval period more demanding -- monitoring the recovery state is beneficial

When recovery was considered, differences were found in the muscle soreness of lower extremities, which increased at a group level only in the interval group. The change differed from the low-intensity group across the training and recovery weeks. Increased muscle soreness at the end of the block was also associated with smaller improvement in the running test. Resting levels of stress hormone norepinephrine concentrations increased after the block in the interval group and remained elevated after the recovery week. The same trend was observed in the nocturnal heart rate variability, which decreased compared to the low-intensity group during the first week of the block.

"Based on the recovery markers we measured, the interval block seemed more demanding compared to the low-intensity block," Nuuttila summarizes. "Therefore, ensuring sufficient recovery especially after such a period would be important. It is also recommendable to monitor recovery at least via subjective markers during these types of blocks to avoid excessive impairment in the recovery state."

The effectiveness of block periodization protocols has not been examined in detail in recreational athletes. Previous studies have not investigated, in particular, both recovery from different perspectives and changes in performance during a block of varying training targets.

Changes in endurance performance were analyzed by a 3000 m running test, and recovery state was monitored with nocturnal heart rate recordings and perceived recovery scales. In addition, resting hormone concentrations were analyzed from urine and blood samples.

Participants were 20- to 45-year-old males and females (15 per group) who trained recreationally. The study was financially supported by the Foundation of Sports Institute and the Finnish Sports Research Foundation. The study was also supported by Firstbeat Analytics Oy, whose heart rate monitors were used in the data collection.

https://www.sciencedaily.com/releases/2022/01/220126144219.htm

Late-life exercise shows rejuvenating effects on cellular level

January 21, 2022

Science Daily/University of Arkansas

For people who hate exercising, here comes some more bad news: it may also keep you younger. Not just looking younger, but actually younger, on an epigenetic level. By now, the benefits of exercise have been well established, including increased strength of bones and muscles, improved mobility and endurance, and lower risk of heart disease, diabetes and high blood pressure.

But younger?

A study recently published in Aging Cell, "Late-life exercise mitigates skeletal muscle epigenetic aging," suggests this could be the case. The paper was written by a team of seven researchers across three institutions, including Kevin Murach, an assistant professor in the Department of Health, Human Performance and Recreation at the U of A. Murach's grant from the National Institute of Health funded the study, and he was one of three co-first authors.

Bootcamp for Mice

While the paper is dense with data, reflecting the use of several analytic tools, the experiment that generated the data was relatively straightforward. Lab mice nearing the end of their natural lifespan, at 22 months, were allowed access to a weighted exercise wheel. Generally, mice require no coercion to run and will do so voluntarily. Older mice will run anywhere from six to eight kilometers a day, mostly in spurts, while younger mice may run up to 10-12 kilometers. The weighted wheel ensured they built muscle. While there isn't a direct analogue to most human exercise routines, Murach likened it to "a soldier carrying a heavy backpack many miles."

When the mice were studied after two months of progressive weighted wheel running, it was determined that they were the epigenetic age of mice eight weeks younger than sedentary mice of the same age -- 24 months. Murach noted that while the specific strain of mice and their housing conditions can impact lifespans, "historically, they start dropping off after 24 months at a significant rate." Needless to say, when your lifespan is measured in months, an extra eight weeks -- roughly 10 percent of that lifespan -- is a noteworthy gain.

Methylation, My Dear Watson

The science behind this, while complicated, hinges largely on a biological process known as DNA methylation. A recent New York Times article discussing Murach's work on muscle memory described methylation "as a process in which clusters of atoms, called methyl groups, attach themselves to the outside of genes like minuscule barnacles, making the genes more or less likely to turn on and produce particular proteins."

As the body ages, there tends to be increased DNA methylation, or even hypermethylation, at promoter sites on genes in muscle. "DNA methylation changes in a lifespan tend to happen in a somewhat systematic fashion," Murach explained, "to the point you can look at someone's DNA from a given tissue sample and with a fair degree of accuracy predict their chronological age." Due to this, researchers can use one of a number of "methylation clocks" to determine the age of a DNA sample.

DNA Methylation, Aging and Exercise

While the paper strengthens the case for exercise, there is still much that needs to be learned. Though the connection between methylation and aging is clear, the connection between methylation and muscle function is less clear. Murach is not yet prepared to say that the reversal of methylation with exercise is causative for improved muscle health. "That's not what the study was set up to do," he explained. However, he intends to pursue future studies to determine if "changes in methylation result in altered muscle function."

"If so, what are the consequences of this?" he continued. "Do changes on these very specific methylation sites have an actual phenotype that emerges from that? Is it what's causing aging or is it just associated with it? Is it just something that happens in concert with a variety of other things that are happening during the aging process? So that's what we don't know."

https://www.sciencedaily.com/releases/2022/01/220121124840.htm

Do we get our most creative ideas when walking?

January 14, 2022

Science Daily/University of Würzburg

Movement helps us to think creatively. This insight is over 2000 years old -- and already known to the philosophers in ancient Greece.

However, what is the connection between movement and cognition from a scientific point of view? What happens in the brain when we walk? Are people who rarely move less creative?

"Our research shows that it is not movement per se that helps us to think more flexibly," says neuroscientist Dr Barbara Händel from Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany. Instead, the freedom to make self-determined movements is responsible for it.

Accordingly, even small movements while sitting can have the same positive effects on creative thinking. However, the researcher does not derive any concrete movement suggestions from her work: "The important thing is the freedom to move without external constraints."

Don't stare at small screens for too long

It is important, she says, that movement is not suppressed or forced into regular patterns. "Unfortunately, this happens when people focus for example on a small screen," explains the JMU researcher.

The increased use of mobile phones and similar devices -- also in the field of education at the time of the Corona pandemic -- could therefore have a negative effect on cognitive processes such as creativity.

The experiments that Barbara Händel and her doctoral student Supriya Murali conducted are described in detail in a recent publication in the journal Psychological Research.

Background

How do people perceive their environment? What effect do sensory stimuli have in the peripheral nervous system and what in the brain? What influence do body movements have on perception of sensory input? Researchers like Barbara Händel are interested in such questions for many reasons. In the long term, their findings could contribute to a better understanding of diseases that affect body movements as well as cognitive processes.

https://www.sciencedaily.com/releases/2022/01/220114115643.htm

Scientists dive deep into the different effects of morning and evening exercise

January 13, 2022

Science Daily/Helmholtz Zentrum München - German Research Center for Environmental Health

It is well established that exercise improves health, and recent research has shown that exercise benefits the body in different ways, depending on the time of day. However, scientists still do not know why the timing of exercise produces these different effects. To gain a better understanding, an international team of scientists recently carried out the most comprehensive study to date of exercise performed at different times of the day.

Their research shows how the body produces different health-promoting signaling molecules in an organ-specific manner following exercise depending on the time of day. These signals have a broad impact on health, influencing sleep, memory, exercise performance, and metabolic homeostasis. Their findings were recently published in the journal Cell Metabolism.

"A better understanding of how exercise affects the body at different times of day might help us to maximize the benefits of exercise for people at risk of diseases, such as obesity and type 2 diabetes," says Professor Juleen R. Zierath from Karolinska Institutet and the Novo Nordisk Foundation Center for Basic Metabolic Research (CBMR) at the University of Copenhagen.

Using exercise to fix a faulty body clock

Almost all cells regulate their biological processes over 24 hours, otherwise called a circadian rhythm. This means that the sensitivity of different tissues to the effects of exercise changes depending on the time of day. Earlier research has confirmed that exercise timing according to our circadian rhythm can optimize the health-promoting effects of exercise.

The team of international scientists wanted a more detailed understanding of this effect, so they carried out a range of experiments on mice that exercised either in the early morning or the late evening. Blood samples and different tissues, including brain, heart, muscle, liver, and fat were collected and analyzed by mass spectrometry. This allowed the scientists to detect hundreds of different metabolites and hormone signaling molecules in each tissue, and to monitor how they were changed by exercising at different times of the day.

The result is an 'Atlas of Exercise Metabolism' -- a comprehensive map of exercise-induced signaling molecules present in different tissues following exercise at different times of day.

"As this is the first comprehensive study that summarizes time and exercise dependent metabolism over multiple tissues, it is of great value to generate and refine systemic models for metabolism and organ crosstalk," adds Dominik Lutter, Head of Computational Discovery Research from the Helmholtz Diabetes Center at Helmholtz Munich.

New insights include a deeper understanding of how tissues communicate with each other, and how exercise can help to 'realign' faulty circadian rhythms in specific tissues -- faulty circadian clocks have been linked to increased risks of obesity and type 2 diabetes. Finally, the study identified new exercise-induced signaling molecules in multiple tissues, which need further investigation to understand how they can individually or collectively influence health.

"Not only do we show how different tissues respond to exercise at different times of the day, but we also propose how these responses are connected to induce an orchestrated adaptation that controls systemic energy homeostasis," says Associate Professor Jonas Thue Treebak from CBMR at the University of Copenhagen, and co-first author of the publication.

A resource for future exercise research

The study has several limitations. The experiments were carried out in mice. While mice share many common genetic, physiological, and behavioral characteristics with humans, they also have important differences. For example, mice are nocturnal, and the type of exercise was also limited to treadmill running, which can produce different results compared to high-intensity exercise. Finally, the impact of sex, age and disease were not considered in the analysis.

"Despite the limitations, it's an important study that helps to direct further research that can help us better understand how exercise, if timed correctly, can help to improve health," says Assistant Professor Shogo Sato from the Department of Biology and the Center for Biological Clocks Research at Texas A&M University, and fellow co-first author.

Fellow co-first author Kenneth Dyar, Head of Metabolic Physiology from the Helmholtz Diabetes Center at Helmholtz Munich, stressed the utility of the atlas as a comprehensive resource for exercise biologists. "While our resource provides important new perspectives about energy metabolites and known signaling molecules, this is just the tip of the iceberg. We show some examples of how our data can be mined to identify new tissue and time-specific signaling molecules," he says.

https://www.sciencedaily.com/releases/2022/01/220113111520.htm

Exercise alters brain chemistry to protect aging synapses

Enhanced nerve transmission seen in older adults who remained active

January 7, 2022

Science Daily/University of California - San Francisco

When elderly people stay active, their brains have more of a class of proteins that enhances the connections between neurons to maintain healthy cognition, a UC San Francisco study has found.

This protective impact was found even in people whose brains at autopsy were riddled with toxic proteins associated with Alzheimer's and other neurodegenerative diseases.

"Our work is the first that uses human data to show that synaptic protein regulation is related to physical activity and may drive the beneficial cognitive outcomes we see," said Kaitlin Casaletto, PhD, an assistant professor of neurology and lead author on the study, which appears in the January 7 issue of Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

The beneficial effects of physical activity on cognition have been shown in mice but have been much harder to demonstrate in people.

Casaletto, a neuropsychologist and member of the Weill Institute for Neurosciences, worked with William Honer, MD, a professor of psychiatry at the University of British Columbia and senior author of the study, to leverage data from the Memory and Aging Project at Rush University in Chicago. That project tracked the late-life physical activity of elderly participants, who also agreed to donate their brains when they died.

"Maintaining the integrity of these connections between neurons may be vital to fending off dementia, since the synapse is really the site where cognition happens," Casaletto said. "Physical activity -- a readily available tool -- may help boost this synaptic functioning."

More Proteins Mean Better Nerve Signals

Honer and Casaletto found that elderly people who remained active had higher levels of proteins that facilitate the exchange of information between neurons. This result dovetailed with Honer's earlier finding that people who had more of these proteins in their brains when they died were better able to maintain their cognition late in life.

To their surprise, Honer said, the researchers found that the effects ranged beyond the hippocampus, the brain's seat of memory, to encompass other brain regions associated with cognitive function.

"It may be that physical activity exerts a global sustaining effect, supporting and stimulating healthy function of proteins that facilitate synaptic transmission throughout the brain," Honer said.

Synapses Safeguard Brains Showing Signs of Dementia

The brains of most older adults accumulate amyloid and tau, toxic proteins that are the hallmarks of Alzheimer's disease pathology. Many scientists believe amyloid accumulates first, then tau, causing synapses and neurons to fall apart.

Casaletto previously found that synaptic integrity, whether measured in the spinal fluid of living adults or the brain tissue of autopsied adults, appeared to dampen the relationship between amyloid and tau, and between tau and neurodegeneration.

"In older adults with higher levels of the proteins associated with synaptic integrity, this cascade of neurotoxicity that leads to Alzheimer's disease appears to be attenuated," she said. "Taken together, these two studies show the potential importance of maintaining synaptic health to support the brain against Alzheimer's disease."

https://www.sciencedaily.com/releases/2022/01/220107100955.htm

Brain function boosted by daily physical activity in middle-aged, older adults

January 31, 2022

Science Daily/University of California - San Diego

A new study by researchers at University of California San Diego School of Medicine adds to the canon of research associating physical activity with cognitive performance, this time using 90 middle-aged and older subjects who wore accelerometers while physically active and completed mobile cognitive testing from home.

"The future of lifestyle interventions really needs to be remote-based," said Raeanne Moore, PhD, associate professor in the Department of Psychiatry at UC San Diego School of Medicine and principal investigator of the study. "The pandemic has made this especially clear."

On the days their physical activity increased, the study found, the 50- to 74-year-old participants performed more effectively on an executive function task, and on the days when their physical activity decreased, so too did their cognitive performance.

The findings published Jan. 31, 2022 in the journal JMIR mHealth and uHealth.

"It was a very linear relationship," Moore said. "We hypothesized that we would find this, but we couldn't be sure because we weren't telling people to increase their physical activity. They just did what they do every day."

First author Zvinka Zlatar, PhD, a clinical psychologist at UC San Diego School of Medicine, added: "Future interventions, in which we ask people to increase their physical activity, will help us determine if daily changes in physical activity lead to daily gains in cognition measured remotely or vice versa."

The correlation between physical activity and cognition remained when adjustments were made for various co-morbidities, such as HIV status, age, sex, education and race/ethnicity. But it held only for persons who function dependently -- who rely on others to perform the tasks of daily living, such as managing household activities or paying the bills.

"For them, physical activity may have a greater benefit on daily, real-world cognitive performance," Moore said, a finding consistent with research into Alzheimer's disease and related dementias.

Though it didn't fall within the purview of this study, Moore speculated that, because functionally independent adults likely perform more cognitively stimulating and social activities, which are known to have positive impacts on brain health, physical activity may have less of an impact on cognition.

Moore and Zlatar said their work has implications for the development of novel digital health interventions to preserve brain health in aging.

"We don't know yet if there's a cumulative, long-term effect to these small daily fluctuations in cognition," Zlatar said. "That's something we plan to study next -- to see if performing physical activity at different intensities over time, in unsupervised settings, can produce long-term improvements in brain health and sustained behavior change."

https://www.sciencedaily.com/releases/2022/01/220131164208.htm

Taking it easy as you get older? Wrong

New research outlines how longer lives are tied to physical activity

November 22, 2021

Science Daily/Harvard University

A team of evolutionary biologists and biomedical researchers lay out evolutionary and biomedical evidence showing that humans, who evolved to live many decades after they stopped reproducing, also evolved to be relatively active in their later years. The researchers say that physical activity later in life shifts energy away from processes that can compromise health and toward mechanisms in the body that extend it. They hypothesize that humans evolved to remain physically active as they age -- and in doing so to allocate energy to physiological processes that slow the body's gradual deterioration over the years. This guards against chronic illnesses such as cardiovascular disease, type 2 diabetes, and even some cancers.

Just about everyone knows that exercise is good for you. Some people can even rattle off reasons it keeps your muscles and joints strong, and how it fights off certain diseases. But how many people can tell you the story of why and how physical activity was built into human biology?

A team of evolutionary biologists and biomedical researchers from Harvard are taking a run at it (sometimes literally) in a new study published in PNAS. The work lays out evolutionary and biomedical evidence showing that humans, who evolved to live many decades after they stopped reproducing, also evolved to be relatively active in their later years.

The researchers say that physical activity later in life shifts energy away from processes that can compromise health and toward mechanisms in the body that extend it. They hypothesize that humans evolved to remain physically active as they age -- and in doing so to allocate energy to physiological processes that slow the body's gradual deterioration over the years. This guards against chronic illnesses such as cardiovascular disease, type 2 diabetes, and even some cancers.

"It's a widespread idea in Western societies that as we get older, it's normal to slow down, do less, and retire," said Harvard evolutionary biologist?Daniel E. Lieberman, the paper's lead author. "Our message is the reverse: As we get older, it becomes even more important to stay physically active."

The research team, which includes Aaron Baggish and I-Min Lee from Harvard Medical School, believes the paper is the first detailed evolutionary explanation for why lack of physical activity as humans age increases disease risk and reduces longevity.

Baggish, 47, who also serves as team cardiologist for the New England Patriots and U.S. Soccer, and Lieberman, 57, are longtime running buddies and often discussed the ideas that went into the paper during 5-to-10-mile morning runs.

The study uses humans' ape cousins as a jumping off point. The researchers point out that apes, which usually live only about 35 to 40 years in the wild and rarely survive past menopause, are considerably less active than most humans, suggesting that there was selection in human evolution not just to live longer but also to be more physically active.

"We evolved basically from couch potatoes," said Lieberman, who has twice observed wild chimpanzees in Tanzania and been surprised by how much of their day is spent "sitting on their butts, digesting."

This is especially jarring when contrasted against contemporary hunter-gatherers, who average about 135 minutes of moderate to vigorous physical activity a day. That level of movement -- about six to ten times more than average Americans -- may be one of the keys to why hunter-gatherers who survive childhood tend to live about seven decades, approximately 20 years past the age at which humans generally stop having children. Fossil evidence indicates that these extended lifespans were common by 40,000 years ago, contrary to the belief that human lifespans until recently were short.

The team emphasized that the key health benefit of physical activity is to extend the human healthspan, which is defined as the years of life spent in good health.

Researchers examined two pathways by which lifelong physical activity reallocates energy to improve health. The first involves dealing excess energy away from potentially harmful mechanisms, like excess fat storage. The team also identified how physical activity allocates energy to repair and maintenance processes. The paper shows that besides burning calories, physical activity is physiologically stressful, causing damage to the body at the molecular, cellular, and tissue levels. The body's response to this damage, however, is essentially to build back stronger.

This includes repairing tears in muscle fibers, repairing cartilage damage, and healing microfractures. The response also causes the release of exercise-related antioxidants and anti-inflammatories, and enhances blood flow. In the absence of physical activity, these responses are activated less. The cellular and DNA repair processes have been shown to lower the risk of diabetes, obesity, cancer, osteoporosis, Alzheimer's, and depression.

"The key take-home point is that because we evolved to be active throughout our lives, our bodies need physical activity to age well. In the past, daily physical activity was necessary in order to survive, but today we have to choose to exercise, that is do voluntary physical activity for the sake of health and fitness," Lieberman said.

The research team, which includes the graduate students Timothy Kistner and Daniel Richard, hope the study makes that message harder to ignore.

Physical activity levels have been decreasing worldwide as machines and technology replace human labor. A recent study from Lieberman's lab showed that Americans are engaging in less physical activity than they did 200 years ago.

The researchers' advice? Get out of your chair and get in some exercise.

"The key is to do something, and to try to make it enjoyable so you'll keep doing it," Lieberman said. "The good news is that you don't need to be as active as a hunter-gatherer. Even small amounts of physical activity -- just 10 or 20 minutes a day -- substantially lower your risk of mortality."

https://www.sciencedaily.com/releases/2021/11/211122172720.htm

Does air pollution reduce the benefits of physical activity on the brain?

December 8, 2021

Science Daily/American Academy of Neurology

A new study shows that people who do vigorous physical activities, like jogging or playing competitive sports, in areas with higher air pollution may show less benefit from that exercise when it comes to certain markers of brain disease. The markers examined in the study included white matter hyperintensities, which indicate injury to the brain's white matter, and gray matter volume. Larger gray matter volumes and smaller white matter hyperintensity volumes are markers of overall better brain health. The research is published in the December 8, 2021, online issue of Neurology®, the medical journal of the American Academy of Neurology.

"Vigorous exercise may increase exposure to air pollution and prior studies have shown adverse effects of air pollution on the brain," said study author Melissa Furlong, PhD, of the University of Arizona in Tucson. "We did show that physical activity is associated with improved markers of brain health in areas with lower air pollution. However, some beneficial effects essentially disappeared for vigorous physical activity in areas with the highest levels of air pollution. That's not to say people should avoid exercise. Overall, the effect of air pollution on brain health was modest -- roughly equivalent to half the effect of one year of aging, while the effects of vigorous activity on brain health were much larger -- approximately equivalent to being three years younger."

The study looked at 8,600 people with an average age of 56 from the UK Biobank, a large biomedical database. People's exposure to pollution, including nitrogen dioxide and particulate matter, which are particles of liquids or solids suspended in the air, was estimated with land use regression. A land use regression study models air pollution levels based on air monitors and land use characteristics like traffic, agriculture and industrial sources of air pollution.

Participants' air pollution exposures were categorized into four equal groups, from lowest air pollution to highest.

Each person's physical activity was measured for one week with a movement-detecting device they wore called an accelerometer. Then researchers characterized their physical activity patterns depending on how much vigorous physical activity they got, ranging from none to 30 minutes or more per week.

People who got the greatest amounts of vigorous physical activity each week, on average, had 800 cm3 gray matter volume, compared to an average of 790 cm3 gray matter volume in people who did not get any vigorous exercise. Researchers showed that air pollution exposures did not alter the effects of physical activity on gray matter volume. However, researchers did find air pollution exposures altered the effects of vigorous physical activity when looking at white matter hyperintensities. After adjusting for age, sex and other covariates, researchers found that vigorous physical activity reduced white matter hyperintensities in areas of low air pollution, but these benefits were not found among those in high air pollution areas.

"More research is needed, but if our findings are replicated, public policy could be used to address people's exposure to air pollution during exercise," Furlong said. "For example, since a significant amount of air pollution comes from traffic, promoting running or bicycling along paths far from heavy traffic may be more beneficial."

https://www.sciencedaily.com/releases/2021/12/211208161118.htm

Minimal effort required: A ten-minute run can boost brain processing

December 6, 2021

Science Daily/University of Tsukuba

Running may be a useful activity to undertake for better mental health. University of Tsukuba researchers have found that only ten minutes of moderate-intensity running increases local blood flow to the various loci in the bilateral prefrontal cortex -- the part of the brain that plays an important role in controlling mood and executive functions. These findings may contribute to the development of a wider range of treatment recommendations to benefit mental health.

There's clear evidence that physical activity has many benefits, such as the ability to improve mood, but in previous studies, cycling was often the form of exercise studied. Running, however, has always played an important role in the well-being of humans. The unique form and efficiency of human running, which includes the ability to sustain this form of exertion (i.e., by jogging as opposed to sprinting), and the evolutionary success of humans are closely linked.

Despite this fact, researchers had not yet looked closely at the effects of running on brain regions that control mood and executive functions. "Given the extent of executive control required in coordinating balance, movement, and propulsion during running, it is logical that there would be increased neuronal activation in the prefrontal cortex and that other functions in this region would benefit from this increase in brain resources," explains Professor Hideaki Soya.

To test their hypothesis, the research team used the well-established Stroop Color-Word Test and captured data on hemodynamic changes associated with brain activity while participants were engaged in each task. For example, in one task, incongruent information is shown, i.e., the word red is written in green, and the participant must name the color rather than read out the word. To do so, the brain must process both sets of information and inhibit the extraneous information. The Stroop interference effect was quantified by the difference in response times for this task and those for a simpler version of the task -- stating the names of color swatches.

The results demonstrated that, after ten minutes of moderate-intensity running, there was a significant reduction in Stroop interference effect time. Furthermore, bilateral prefrontal activation had significantly increased during the Stroop task. After running, participants reported being in a better mood. "This was supported by findings of coincident activations in the prefrontal cortical regions involved in mood regulation," first author Chorphaka Damrongthai adds.

Given that many characteristics of the human prefrontal cortex are uniquely human, this study not only sheds light on the present benefits of running but also on the possible role that these benefits may have played in the evolutionary past of humans.

https://www.sciencedaily.com/releases/2021/12/211206113037.htm