Memory Function is Improved With Mild Physical Activity

Strong memory function is valuable in today’s advanced, technologically-driven society.

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People who include a little yoga or tai chi in their day may be more likely to remember where they put their keys. Researchers at the University of California, Irvine and Japan’s University of Tsukuba found that even very light workouts can increase the connectivity between parts of the brain responsible for memory formation and storage.

In a study of 36 healthy young adults, the researchers discovered that a single 10-minute period of mild exertion can yield considerable cognitive benefits. Using high-resolution functional magnetic resonance imaging, the team examined subjects’ brains shortly after exercise sessions and saw better connectivity between the hippocampal dentate gyrus and cortical areas linked to detailed memory processing.

Their results were published today in Proceedings of the National Academy of Sciences.

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The neuroscientists found that the level of heightened connectivity predicted the degree of recall enhancement.

Yassa, director of UCI’s Center for the Neurobiology of Learning and Memory and the recently launched UCI Brain Initiative, said that while prior research has centered on the way exercise promotes the generation of new brain cells in memory regions, this new study demonstrates a more immediate impact: strengthened communication between memory-focused parts of the brain.

“We don’t discount the possibility that new cells are being born, but that’s a process that takes a bit longer to unfold,” he said. “What we observed is that these 10-minute periods of exercise showed results immediately afterward.”

A little bit of physical activity can go a long way, Yassa stressed. “It’s encouraging to see more people keeping track of their exercise habits — by monitoring the number of steps they’re taking, for example,” he said. “Even short walking breaks throughout the day may have considerable effects on improving memory and cognition.”

Yassa and his colleagues at UCI and at the University of Tsukuba are extending this avenue of research by testing older adults who are at greater risk of age-related mental impairment and by conducting long-term interventions to see if regular, brief, light exercise done daily for several weeks or months can have a positive impact on the brain’s structure and function in these subjects.

The Unique Benefits Anaerobic Exercise Has on Fat Cells

Turns out that lifting can have positive effects on body fat at the cellular level. Muscles are also a main way for the body to store amino acids to fight infections.

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We all know that lifting weights can build up our muscles. But by changing the inner workings of cells, weight training may also shrink fat, according to an enlightening new study of the molecular underpinnings of resistance exercise. The study, which involved mice and people, found that after weight training, muscles create and release little bubbles of genetic material that can flow to fat cells, jump-starting processes there related to fat burning.

The results add to mounting scientific evidence that resistance exercise has unique benefits for fat loss. They also underscore how extensive and interconnected the internal effects of exercise can be.

Many of us pigeonhole resistance training as muscle building, and with good reason. Lifting weights — or working against our body weight as we bob through push-ups, squats or chair dips — will noticeably boost our muscles’ size and strength. But a growing number of studies suggest weight training also reshapes our metabolisms and waistlines. In recent experiments, weight workouts goosed energy expenditure and fat burning for at least 24 hours afterward in young womenoverweight men and athletes. Likewise, in a study I covered earlier this month, people who occasionally lifted weights were far less likely to become obese than those who never lifted.

But how weight training revamps body fat remains murky. Part of the effect occurs because muscle is metabolically active and burns calories, so adding muscle mass by lifting should increase energy expenditure and resting metabolic rates. After six months of heavy lifting, for example, muscles will burn more calories just because they are larger. But that doesn’t fully explain the effect, because adding muscle mass requires time and repetition, while some of the metabolic effects of weight training on fat stores seem to occur immediately after exercise.

Perhaps, then, something happens at a molecular level right after resistance workouts that targets fat cells, a hypothesis that a group of scientists at the University of Kentucky in Lexington, the University of Nebraska-Lincoln and other institutions recently decided to investigate. The researchers had been studying muscle health for years, but had grown increasingly interested in other tissues, especially fat. Maybe, they speculated, muscles and fat chatted together amiably after a workout.

In the past decade, the idea that cells and tissues communicate across the expanse of our bodies has become widely accepted, though the complexity of the interactions remains boggling. Sophisticated experiments show that muscles, for instance, release a cascade of hormones and other proteins after exercise that enter the bloodstream, course along to various organs and trigger biochemical reactions there, in a process known as cellular crosstalk.

Our tissues also may pump out tiny bubbles, known as vesicles, during crosstalk. Once considered microscopic trash bags, stuffed with cellular debris, vesicles now are known to contain active, healthy genetic material and other substances. Released into the bloodstream, they relay this biological matter from one tissue to another, like minuscule messages in bottles.

Intriguingly, some experiments indicate that aerobic exercise prompts muscles to release such vesicles, conveying a variety of messages. But few studies had looked into whether resistance exercise might also result in vesicle formation and inter-tissue chatter.

So, for the new study, which was published in May in The FASEB Journal, from the Federation of American Societies for Experimental Biology, the researchers decided to examine the cells of bodybuilding mice. They first experimentally incapacitated several of the leg muscles in healthy adult mice, leaving a single muscle to carry all the physical demands of movement. That muscle swiftly hypertrophied, or bulked up, providing an accelerated version of resistance training.

Before and after that process, the researchers drew blood, biopsied tissues, centrifuged fluids and microscopically searched for vesicles and other molecular changes in the tissues.

They noted plenty. Before their improvised weight training, the rodents’ leg muscles had teemed with a particular snippet of genetic material, known as miR-1, that modulates muscle growth. In normal, untrained muscles, miR-1, one of a group of tiny strands of genetic material known as microRNA, keeps a brake on muscle building.

After the rodents’ resistance exercise, which consisted of walking around, though, the animals’ leg muscles appeared depleted of miR-1. At the same time, the vesicles in their bloodstream now thronged with the stuff, as did nearby fat tissue. It seems, the scientists concluded, that the animals’ muscle cells somehow packed those bits of microRNA that retard hypertrophy into vesicles and posted them to neighboring fat cells, which then allowed the muscles immediately to grow.

But what was the miR-1 doing to the fat once it arrived, the scientist wondered? To find out, they marked vesicles from weight-trained mice with a fluorescent dye, injected them into untrained animals, and tracked the glowing bubbles’ paths. The vesicles homed in on fat, the scientists saw, then dissolved and deposited their miR-1 cargo there.

Soon after, some of the genes in the fat cells went into overdrive. These genes help direct the breakdown of fat into fatty acids, which other cells then can use as fuel, reducing fat stores. In effect, weight training was shrinking fat in mice by creating vesicles in muscles that, through genetic signals, told the fat it was time to break itself apart.

“The process was just remarkable,” said John J. McCarthy, a professor of physiology at the University of Kentucky, who was an author of the study with his then graduate student Ivan J. Vechetti Jr. and other colleagues.

Mice are not people, though. So, as a final facet of the study, the scientists gathered blood and tissue from healthy men and women who had performed a single, fatiguing lower-body weight workout and confirmed that, as in mice, miR-1 levels in the volunteers’ muscles dropped after their lifting, while the quantity of miR-1-containing vesicles in their bloodstreams soared.

Of course, the study mostly involved mice and was not designed to tell us how often or intensely we should lift to maximize vesicle output and fat burn. But, even so, the results serve as a bracing reminder that “muscle mass is vitally important for metabolic health,” Dr. McCarthy said, and that we start building that mass and getting our tissues talking every time we hoist a weight.

Lifelong Exercise Shown to Slow Aging

The benefits of exercise are underrated much too often.

Researchers at the University of Birmingham and King’s College London have found that staying active keeps the body young and healthy.

The researchers set out to assess the health of older adults who had exercised most of their adult lives to see if this could slow down ageing.

The study recruited 125 amateur cyclists aged 55 to 79, 84 of which were male and 41 were female. The men had to be able to cycle 100 km in under 6.5 hours, while the women had to be able to cycle 60 km in 5.5 hours. Smokers, heavy drinkers and those with high blood pressure or other health conditions were excluded from the study.

The participants underwent a series of tests in the laboratory and were compared to a group of adults who do not partake in regular physical activity. This group consisted of 75 healthy people aged 57 to 80 and 55 healthy young adults aged 20 to 36.

The study showed that loss of muscle mass and strength did not occur in those who exercise regularly. The cyclists also did not increase their body fat or cholesterol levels with age and the men’s testosterone levels also remained high, suggesting that they may have avoided most of the male menopause.

More surprisingly, the study also revealed that the benefits of exercise extend beyond muscle as the cyclists also had an immune system that did not seem to have aged either.

An organ called the thymus, which makes immune cells called T cells, starts to shrink from the age of 20 and makes less T cells. In this study, however, the cyclists’ thymuses were making as many T cells as those of a young person.

The findings come as figures show that less than half of over 65s do enough exercise to stay healthy and more than half of those aged over 65 suffer from at least two diseases.* Professor Janet Lord, Director of the Institute of Inflammation and Ageing at the University of Birmingham, said: “Hippocrates in 400 BC said that exercise is man’s best medicine, but his message has been lost over time and we are an increasingly sedentary society.

“However, importantly, our findings debunk the assumption that ageing automatically makes us more frail.

“Our research means we now have strong evidence that encouraging people to commit to regular exercise throughout their lives is a viable solution to the problem that we are living longer but not healthier.”

Dr Niharika Arora Duggal, also of the University of Birmingham, said: “We hope these findings prevent the danger that, as a society, we accept that old age and disease are normal bedfellows and that the third age of man is something to be endured and not enjoyed.”

Professor Stephen Harridge, Director of the Centre of Human & Aerospace Physiological Sciences at King’s College London, said: “The findings emphasise the fact that the cyclists do not exercise because they are healthy, but that they are healthy because they have been exercising for such a large proportion of their lives.

“Their bodies have been allowed to age optimally, free from the problems usually caused by inactivity. Remove the activity and their health would likely deteriorate.”

Norman Lazarus, Emeritus Professor at King’s College London and also a master cyclist and Dr Ross Pollock, who undertook the muscle study, both agreed that: “Most of us who exercise have nowhere near the physiological capacities of elite athletes.

“We exercise mainly to enjoy ourselves. Nearly everybody can partake in an exercise that is in keeping with their own physiological capabilities.

“Find an exercise that you enjoy in whatever environment that suits you and make a habit of physical activity. You will reap the rewards in later life by enjoying an independent and productive old age.”

Exercising Regularly Strengthens the Immune System

A good thing to keep in mind during a pandemic.

Being in isolation without access to gyms and sports clubs should not mean people stop exercising, according to a new study from researchers at the University of Bath. Keeping up regular, daily exercise at a time when much of the world is going into isolation will play an important role in helping to maintain a healthy immune system.

The analysis, published in the international journal Exercise Immunology Review, involving leading physiologists Dr James Turner and Dr John Campbell from the University of Bath’s Department for Health, considers the effect of exercise on our immune function.

Over the last four decades, many studies have investigated how exercise affects the immune system. It is widely agreed that regular moderate intensity exercise is beneficial for immunity, but a view held by some is that more arduous exercise can suppress immune function, leading to an ‘open-window’ of heightened infection risk in the hours and days following exercise.

In a benchmark study in 2018, this ‘open window’ hypothesis was challenged by Dr Campbell and Dr Turner. They reported in a review article that the theory was not well supported by scientific evidence, summarising that there is limited reliable evidence that exercise suppresses immunity, concluding instead that exercise is beneficial for immune function.

They say that, in the short term, exercise can help the immune system find and deal with pathogens, and in the long term, regular exercise slows down changes that happen to the immune system with ageing, therefore reducing the risk of infections.