Spending time outdoors has positive effect on our brains

July 15, 2021

Science Daily/Max Planck Institute for Human Development

If you're regularly out in the fresh air, you're doing something good for both your brain and your well-being. This is the conclusion reached by researchers at the Max Planck Institute for Human Development and the Medical Center Hamburg-Eppendorf (UKE). The longitudinal study recently appeared in The World Journal of Biological Psychiatry.

During the Corona pandemic, walks became a popular and regular pastime. A neuroscientific study suggests that this habit has a good effect not only on our general well-being but also on our brain structure. It shows that the human brain benefits from even short stays outdoors. Until now, it was assumed that environments affect us only over longer periods of time.

The researchers regularly examined six healthy, middle-aged city dwellers for six months. In total, more than 280 scans were taken of their brains using magnetic resonance imaging (MRI). The focus of the study was on self-reported behavior during the last 24 hours and in particular on the hours that participants spent outdoors prior to imaging. In addition, they were asked about their fluid intake, consumption of caffeinated beverages, the amount of time spent outside, and physical activity, in order to see if these factors altered the association between time spent outside and the brain. In order to be able to include seasonal differences, the duration of sunshine in the study period was also taken into account.

Brain scans show that the time spent outdoors by the participants was positively related to gray matter in the right dorsolateral-prefrontal cortex, which is the superior (dorsal) and lateral part of the frontal lobe in the cerebral cortex. This part of the cortex is involved in the planning and regulation of actions as well as what is referred to as cognitive control. In addition, many psychiatric disorders are known to be associated with a reduction in gray matter in the prefrontal area of the brain.

The results persisted even when the other factors that could also explain the relationship between time spent outdoors and brain structure were kept constant. The researchers performed statistical calculations in order to examine the influence of sunshine duration, number of hours of free time, physical activity, and fluid intake on the results. The calculations revealed that time spent outdoors had a positive effect on the brain regardless of the other influencing factors.

"Our results show that our brain structure and mood improve when we spend time outdoors. This most likely also affects concentration, working memory, and the psyche as a whole. We are investigating this in an ongoing study. The subjects are asked to also solve cognitively challenging tasks and wear numerous sensors that measure the amount of light they are exposed to during the day, among other environmental indicators," says Simone Kühn, head of the Lise Meitner Group for Environmental Neuroscience at the Max Planck Institute for Human Development and lead author of the study.

The results therefore, support the previously assumed positive effects of walking on health and extend them by the concrete positive effects on the brain. Because most psychiatric disorders are associated with deficits in the prefrontal cortex, this is of particular importance to the field of psychiatry.

"These findings provide neuroscientific support for the treatment of mental disorders. Doctors could prescribe a walk in the fresh air as part of the therapy -- similar to what is customary for health cures," says Anna Mascherek, post-doctoral fellow in the Department of Psychiatry and Psychotherapy of the Medical Center Hamburg-Eppendorf (UKE) and co-author of the study.

In the ongoing studies, the researchers also want to directly compare the effects of green environments vs urban spaces on the brain. In order to understand where exactly the study participants spend their time outdoors, the researchers plan to use GPS (Global Positioning System) data and include other factors that may play a role such as traffic noise and air pollution.

https://www.sciencedaily.com/releases/2021/07/210715103025.htm

Memory biomarkers confirm aerobic exercise helps cognitive function in older adults

Study conducted on older adults with familial and genetic risk for Alzheimer's disease

June 10, 2021

Science Daily/Florida Atlantic University

Increasing evidence shows that physical activity and exercise training may delay or prevent the onset of Alzheimer's disease (AD). In aging humans, aerobic exercise training increases gray and white matter volume, enhances blood flow, and improves memory function. The ability to measure the effects of exercise on systemic biomarkers associated with risk for AD and relating them to key metabolomic alterations may further prevention, monitoring, and treatment efforts. However, systemic biomarkers that can measure exercise effects on brain function and that link to relevant metabolic responses are lacking.

To address this issue, Henriette van Praag, Ph.D., from Florida Atlantic University's Schmidt College of Medicine and Brain Institute and Ozioma Okonkwo, Ph.D., Wisconsin Alzheimer's Disease Research Center and Department of Medicine at the University of Wisconsin-Madison and their collaborators, tested the hypotheses that three specific biomarkers, which are implicated in learning and memory, would increase in older adults following exercise training and correlate with cognition and metabolomics markers of brain health. They examined myokine Cathepsin B (CTSB), brain derived neurotrophic factor (BDNF), and klotho, as well as metabolomics, which have become increasingly utilized to understand biochemical pathways that may be affected by AD.

Researchers performed a metabolomics analysis in blood samples of 23 asymptomatic late middle-aged adults, with familial and genetic risk for AD (mean age 65 years old, 50 percent female) who participated in the "aeRobic Exercise And Cognitive Health (REACH) Pilot Study" (NCT02384993) at the University of Wisconsin. The participants were divided into two groups: usual physical activity (UPA) and enhanced physical activity (EPA). The EPA group underwent 26 weeks of supervised treadmill training. Blood samples for both groups were taken at baseline and after 26 weeks.

Results of the study, published in the journal Frontiers in Endocrinology, showed that plasma CTSB levels were increased following this 26-week structured aerobic exercise training in older adults at risk for AD. Verbal learning and memory correlated positively with change in CTSB but was not related to BDNF or klotho. The present correlation between CTSB and verbal learning and memory suggests that CTSB may be useful as a marker for cognitive changes relevant to hippocampal function after exercise in a population at risk for dementia.

Plasma BDNF levels decreased in conjunction with metabolomic changes, including reductions in ceramides, sphingo- and phospholipids, as well as changes in gut microbiome metabolites and redox homeostasis. Indeed, multiple lipid metabolites relevant to AD were modified by exercise in a manner that may be neuroprotective. Serum klotho was unchanged but was associated with cardiorespiratory fitness.

"Our findings position CTSB, BDNF, and klotho as exercise biomarkers for evaluating the effect of lifestyle interventions on brain function," said van Praag, corresponding author, an associate professor of biomedical science, FAU's Schmidt College of Medicine, and a member of the FAU Brain Institute and the FAU Institute for Human Health & Disease Intervention (I-HEALTH). "Human studies often utilize expensive and low throughput brain imaging analyses that are not practical for large population-wide studies. Systemic biomarkers that can measure the effect of exercise interventions on Alzheimer's-related outcomes quickly and at low-cost could be used to inform disease progression and to develop novel therapeutic targets."

CTSB, a lysosomal enzyme, is secreted from muscle into circulation after exercise and is associated with memory function and adult hippocampal neurogenesis. Older adults with cognitive impairment have lower serum and brain CTSB levels. BDNF is a protein that is upregulated in the rodent hippocampus and cortex by running and is important for adult neurogenesis, synaptic plasticity, and memory function. Klotho is a circulating protein that can enhance cognition and synaptic function and is associated with resilience to neurodegenerative disease, possibly by supporting brain structures responsible for memory and learning.

"The positive association between CTSB and cognition, and the substantial modulation of lipid metabolites implicated in dementia, support the beneficial effects of exercise training on brain function and brain health in asymptomatic individuals at risk for Alzheimer's disease," said van Praag.

https://www.sciencedaily.com/releases/2021/06/210610135527.htm

Women's mental health has higher association with dietary factors

Exercise could reduce negative association of certain food and mental distress in mature women

June 9, 2021

Science Daily/Binghamton University

Women's mental health likely has a higher association with dietary factors than men's, according to new research from Binghamton University, State University of New York.

Lina Begdache, assistant professor of health and wellness studies at Binghamton University, had previously published research on diet and mood that suggests that a high-quality diet improves mental health. She wanted to test whether customization of diet improves mood among men and women ages 30 or older.

Along with research assistant Cara M. Patrissy, Begdache dissected the different food groups that are associated with mental distress in men and women ages 30 years and older, as well as studied the different dietary patterns in relation to exercise frequency and mental distress. The results suggest that women's mental health has a higher association with dietary factors than that of men. Mental distress and exercise frequency were associated with different dietary and lifestyle patterns, which support the concept of customizing diet and lifestyle factors to improve mental wellbeing.

"We found a general relationship between eating healthy, following healthy dietary practices, exercise and mental well-being," said Begdache. "Interestingly, we found that for unhealthy dietary patterns, the level of mental distress was higher in women than in men, which confirmed that women are more susceptible to unhealthy eating than men."

Based on this study and others, diet and exercise may be the first line of defense against mental distress in mature women, said Begdache.

"Fast food, skipping breakfast, caffeine and high-glycemic (HG) food are all associated with mental distress in mature women," said Begdache. "Fruits and dark green leafy vegetables (DGLV) are associated with mental well-being. The extra information we learned from this study is that exercise significantly reduced the negative association of HG food and fast food with mental distress," said Begadache.

This research provides the framework needed for healthcare professionals for customizing dietary plans to promote exercise and improve mental well-being in mature adults, said Begdache. It could also provide a new perspective for the research community when assessing the role of diet on mental distress.

The researchers are conducting a parallel study with young men and women, looking at diet quality in addition to sleep and seasonal change variables from a longitudinal perspective.

https://www.sciencedaily.com/releases/2021/06/210609143348.htm

Exercise likely to be best treatment for depression in coronary heart disease

June 8, 2021

Science Daily/RCSI

A study by RCSI indicates that exercise is probably the most effective short-term treatment for depression in people with coronary heart disease, when compared to antidepressants and psychotherapy or more complex care.

The study, led by researchers at RCSI University of Medicine and Health Sciences, is published in the June edition of Psychosomatic Medicine.

This is the first systematic review to compare treatments for depression in those with coronary disease and the findings provides valuable clinical information to help doctors determine the best treatment plan for patients.

The researchers reviewed treatment trials which investigated antidepressants, psychotherapy, exercise, combined psychotherapy and antidepressants, and collaborative care (i.e. treatments devised by a multidisciplinary team of clinicians with input from the patient).

To measure effectiveness, the researchers looked at factors including patient adherence to the treatment (dropout rate) and change in depressive symptoms eight weeks after commencing treatment.

The strongest treatment effects were found to be exercise and combination treatments (antidepressants and psychotherapy). However, as the combination study results have a high risk of bias, the findings of the review suggest that exercise is probably the most effective treatment. Antidepressants had the most research support, while psychotherapy and collaborative care did not perform very well.

"Depression is common in patients with coronary artery disease. Having both conditions can have a significant impact on the quality of life for patients so it is vital that they access to the most effective treatments," commented Dr Frank Doyle, Senior Lecturer Division of Population Health Sciences, RCSI and the study's first author.

"Our study indicates that exercise is likely to be the best treatment for depression following coronary artery disease. Our findings further highlight the clinical importance of exercise as a treatment as we see that it improves not only depression, but also other important aspects of heart disease, such as lowering blood pressure and cholesterol, in these patients."

"We continue to see emerging evidence of the importance of lifestyle to treat disease -- in comparison to other treatments -- but further high-quality research is needed. People with coronary heart disease who have symptoms of depression should talk to their doctor about treatments that are most suitable for their personal needs, and clinicians can be confident of recommending exercise to their patients."

Dr Frank Doyle and the study's senior authors, Prof. Jan Sorensen (Health Outcomes Research Centre, RCSI) and Prof. Martin Dempster (School of Psychology, Queen's University Belfast), conducted the study in collaboration with researchers in the USA, The Netherlands, the UK and Denmark.

This study was also the first of its kind to establish a new method to conduct systematic reviews known as a hybrid review, which is a combination of umbrella reviews and systematic reviews.

https://www.sciencedaily.com/releases/2021/06/210608113205.htm

How to boost muscle regeneration and rebuild tissue

Clues about molecular changes underlying muscle loss tied to aging

May 25, 2021

Science Daily/Salk Institute

One of the many effects of aging is loss of muscle mass, which contributes to disability in older people. To counter this loss, scientists at the Salk Institute are studying ways to accelerate the regeneration of muscle tissue, using a combination of molecular compounds that are commonly used in stem-cell research.

In a study published on May 25, 2021, in Nature Communications, the investigators showed that using these compounds increased the regeneration of muscle cells in mice by activating the precursors of muscle cells, called myogenic progenitors. Although more work is needed before this approach can be applied in humans, the research provides insight into the underlying mechanisms related to muscle regeneration and growth and could one day help athletes as well as aging adults regenerate tissue more effectively.

"Loss of these progenitors has been connected to age-related muscle degeneration," says Salk Professor Juan Carlos Izpisua Belmonte, the paper's senior author. "Our study uncovers specific factors that are able to accelerate muscle regeneration, as well as revealing the mechanism by which this occurred."

The compounds used in the study are often called Yamanaka factors after the Japanese scientist who discovered them. Yamanaka factors are a combination of proteins (called transcription factors) that control how DNA is copied for translation into other proteins. In lab research, they are used to convert specialized cells, like skin cells, into more stem-cell-like cells that are pluripotent, which means they have the ability to become many different types of cells.

"Our laboratory previously showed that these factors can rejuvenate cells and promote tissue regeneration in live animals," says first author Chao Wang, a postdoctoral fellow in the Izpisua Belmonte lab. "But how this happens was not previously known."

Muscle regeneration is mediated by muscle stem cells, also called satellite cells. Satellite cells are located in a niche between a layer of connective tissue (basal lamina) and muscle fibers (myofibers). In this study, the team used two different mouse models to pinpoint the muscle stem-cell-specific or niche-specific changes following addition of Yamanaka factors. They focused on younger mice to study the effects of the factors independent of age.

In the myofiber-specific model, they found that adding the Yamanaka factors accelerated muscle regeneration in mice by reducing the levels of a protein called Wnt4 in the niche, which in turn activated the satellite cells. By contrast, in the satellite-cell-specific model, Yamanaka factors did not activate satellite cells and did not improve muscle regeneration, suggesting that Wnt4 plays a vital role in muscle regeneration.

According to Izpisua Belmonte, who holds the Roger Guillemin Chair, the observations from this study could eventually lead to new treatments by targeting Wnt4.

"Our laboratory has recently developed novel gene-editing technologies that could be used to accelerate muscle recovery after injury and improve muscle function," he says. "We could potentially use this technology to either directly reduce Wnt4 levels in skeletal muscle or to block the communication between Wnt4 and muscle stem cells."

The investigators are also studying other ways to rejuvenate cells, including using mRNA and genetic engineering. These techniques could eventually lead to new approaches to boost tissue and organ regeneration.

https://www.sciencedaily.com/releases/2021/05/210525113717.htm

Stair climbing offers significant cardiovascular and muscular benefits for heart patients

May 17, 2021

Science Daily/McMaster University

A team of McMaster University researchers who studied heart patients found that stair-climbing routines, whether vigorous or moderate, provide significant cardiovascular and muscular benefits.

The findings, published in closely related studies in the journals Medicine & Science in Sports & Exercise and Frontiers, address the most frequently cited barriers to exercise: time, equipment and access to gym facilities.

"Brief, vigorous stair-climbing and traditional moderate intensity exercise both changed fitness, which is a key predictor of mortality after a cardiac event," says Maureen MacDonald, one of the lead researchers on both studies and a professor in McMaster's Department of Kinesiology.

"We've shown stair-climbing is a safe, efficient and feasible option for cardiac rehabilitation, which is particularly relevant during the pandemic when many people don't have the option to exercise in a gym," she says.

While it is widely known that exercise and lifestyle changes reduce the risk of secondary cardiovascular disease, statistics suggest less than a quarter of all cardiac patients adhere to fitness programs.

Researchers worked closely with the Cardiac Health and Rehabilitation Centre at the Hamilton General Hospital to develop an exercise protocol that did not require specialized equipment or monitoring and could be easily performed outside a laboratory.

Participants with coronary artery disease who had undergone a cardiac procedure were randomly assigned either to traditional moderate-intensity exercise or vigorous stair climbing: three rounds of six flights of 12 stairs, separated by recovery periods of walking, with participants selecting their own stepping pace.

Researchers compared the results and found that individuals who had done traditional exercise and those who had done stair-climbing both increased their cardiorespiratory fitness after four weeks of supervised training and maintained those levels for an additional eight weeks of unsupervised training.

They also reported substantial muscular improvement.

"These patients who had undergone a coronary bypass or stent procedure had muscle that was compromised, compared to age-matched healthy controls," explained Stuart Phillips, a co-author of the studies and a professor in the Department of Kinesiology at McMaster who oversaw the analysis of muscle tissue taken during the study.

Previously, there had been very few studies of the impact of exercise on cardiac patients' muscle specifically. This analysis shows heart patients can still repair and build lost muscle.

"Even in just a short period, whether it was moderate intensity, continuous training or high-intensity stair climbing, there were beneficial adaptations in muscles after a cardiac procedure," Phillips says. "The improvements were clear."

https://www.sciencedaily.com/releases/2021/05/210517102635.htm

Secret behind maintaining a healthy weight loss

May 6, 2021

Science Daily/University of Copenhagen - The Faculty of Health and Medical Sciences

Half of the Danish population have overweight, while 17 percent live with obesity. Worldwide, almost 40 procent have overweight and 13 procent live with obesity.

The condition is associated with increased risk for early death, as well as sequelae such as Type 2 diabetes, cardiovascular diseases, cancer, and infertility.

Weight regain after an initial successful weight loss in people with obesity, constitutes an important and unsolved problem. Until now, no well-documented study on which treatment method is best for maintaining a healthy weight loss has been available.

Researchers at University of Copenhagen and Hvidovre Hospital have completed a new, sensational study, which is being published in the world's most quoted medical journal, The New England Journal of Medicine. By testing four different types of treatment following a diet-induced weight loss, the researchers demonstrate for the first time how it is possible for people with obesity to maintain long-term weight loss, says Professor Signe Torekov at the Department of Biomedical Sciences.

In a randomized clinical trial, the group of researchers has demonstrated a highly effective treatment after a diet-induced weight loss, by combining moderate to vigorous-intensive exercise with appetite-inhibiting obesity medication, an analogue to the appetite-inhibiting hormone GLP-1.

"This is new knowledge for doctors, dietitians and physical therapists to use in practice. This is evidence that we have been missing," explains Signe Torekov, who has been heading the study.

"The problem is that people are fighting against strong biological forces when losing weight. The appetite increases simultaneously with decreased energy consumption, and this counteracts weight loss maintenance. We have an appetite-stimulating hormone, which increases dramatically when we lose weight, and simultaneously the level of appetite-suppressing hormones drops dramatically. In addition, a weight loss can provoke loss of muscle mass, while the body reduces the energy consumption. Thus, when the focus in obesity treatment has been on how to obtain a weight loss -- rather than how to maintain a weight loss -- it is really difficult to do something about your situation," says Signe Torekov.

Highly efficient when combining treatments

215 Danes with obesity and low fitness ratings participated in the study. The participants initially followed a low calorie diet over eight weeks, where they each lost approximately 13 kg, which brought significant improvements to their health with a drop in blood sugar level and blood pressure.

The participants were then randomly divided into four groups. Two of the groups received placebo medication, while the two other groups received obesity medication. Among the two placebo groups, one group followed an exercise program of minimum 150 minutes of physical activity at moderate intensity or 75 minutes at vigorous-intensity during the week or a combination of the two, while the other group maintained their current level of physical activity. The two groups receiving obesity medication were similarly divided into one group with and one group without an exercise program.

All participants in the study were weighed monthly and received nutritional and diet counseling with the focus on healthy weight loss according to the guidelines from the Danish health and food administrations.

After one year, the group with exercise alone and the group with obesity medication alone maintained the weight loss of 13 kg and health improvements. The placebo group gained half of the weight back with deterioration of all risk factors, for example for development of Type 2 diabetes and cardiovascular disease.

The most dramatic improvements occurred in the combination group, which followed the exercise program and received obesity medication. The researchers observed additional weight loss in this group, and the total weight loss was approximately 16 kg over one year. The health benefits were also double that of each of the single treatments, i.e., twice the loss of fat mass while preserving muscle mass, higher fitness ratings, reduced blood sugar and improved quality of life.

The two groups that exercised increased their fitness rating, lost fat mass, and gained muscle mass. This could indicate a healthier weight loss than for people, who had only lost fat mass without increasing the fitness rating.

"It is an important aspect to highlight, as you do not necessarily get a healthier body from losing weight if, at the same time, you lose a lot of muscle mass," says Signe Torekov.

"It is great news for public health that a significant weight loss can be maintained with exercise for approximately 115 minute per week performed mostly at vigorous-intensity, such as cycling. And that by combining exercise with obesity medication, the effect is twice as good as each of the individual treatments." "

With the study, the researchers now hope people with obesity, together with their care provider, can create a useful framework for maintaining the weight loss.

Fundamental lifestyle change

Signe Torekov points out that many people with obesity have tried to lose weight before, only to regain the weight. This happens, because the general advice is to eat healthier and exercise more.

"Without a follow-up on whether people actually have support to perform exercise, the treatment will not be enough. Therefore, we also followed up with the participants on an ongoing basis to ensure that they received the support they needed in order to exercise. That is necessary, because maintaining weight loss is extremely hard. People need to understand this. Once you have lost weight, you are not "cured." "The ongoing exercise and effort will likely need to continue for many years," says Signe Torekov.

"Our study also demonstrates that without a structured treatment plan, there is a high risk of gaining the weight back. There were 12 individual consultations over the course of a year, including weighing and diet advice from Danish authorities according to guidelines for healthy weight maintenance. This was just not enough for the placebo group without exercise program, in this group all health benefits gained by weight loss during the eight week program were gone after one year, despite frequent weighing and diet and nutritional counseling based on official guidelines." Torekov says.

According to Signe Torekov, this underscores the importance of participating in a mutual weight maintenance program based on feedback when starting a weight loss programme.

"Therefore, it is important that there is a system for supporting people with obesity in maintaining the lifestyle change. Our study can help with this, because we can say this actually works to doctors, dietitians and municipalities, if they create a structured, joint treatment plan with the individual using ongoing follow-ups," says Torekov.

https://www.sciencedaily.com/releases/2021/05/210506105344.htm

Want to be robust at 40-plus? Meeting minimum exercise guidelines won't cut it

5 hours of moderate activity a week may be required to avoid midlife hypertension

April 15, 2021

Science Daily/University of California - San Francisco

Young adults must step up their exercise routines to reduce their chances of developing high blood pressure or hypertension -- a condition that may lead to heart attack and stroke, as well as dementia in later life.

Current guidelines indicate that adults should have a minimum of two-and-a-half hours of moderate intensity exercise each week, but a new study led by UCSF Benioff Children's Hospitals reveals that boosting exercise to as much as five hours a week may protect against hypertension in midlife -- particularly if it is sustained in one's thirties, forties and fifties.

In the study publishing in American Journal of Preventive Medicineon April 15, researchers followed approximately 5,000 adults ages 18 to 30 for 30 years. The participants were asked about their exercise habits, medical history, smoking status and alcohol use. Blood pressure and weight were monitored, together with cholesterol and triglycerides.

Hypertension was noted if blood pressure was 130 over 80 mmHg, the threshold established in 2017 by the American College of Cardiology/American Heart Association.

The 5,115 participants had been enrolled by the Coronary Artery Risk Development in Young Adults (CARDIA) study and came from urban sites in Birmingham, Ala., Chicago, Minneapolis and Oakland, Calif. Approximately half the participants were Black (51.6 percent) and the remainder were White. Just under half (45.5 percent) were men.

Fitness Levels Fall Fast for Black Men Leading to More Hypertension

Among the four groups, who were categorized by race and gender, Black men were found to be the most active in early adulthood, exercising slightly more than White men and significantly more than Black women and White women. But by the time Black men reached age 60, exercise intake had slumped from a peak of approximately 560 exercise units to around 300 units, the equivalent to the minimum of two-and-a-half hours a week of moderate intensity exercise recommended by the U.S. Department of Health and Human Services. This was substantially less exercise than White men (approximately 430 units) and slightly more than White women (approximately 320 units). Of the four groups, Black women had the least exercise throughout the study period and saw declines over time to approximately 200 units.

"Although Black male youth may have high engagement in sports, socio-economic factors, neighborhood environments, and work or family responsibilities may prevent continued engagement in physical activity through adulthood," said first author Jason Nagata, MD, of the UCSF Division of Adolescent and Young Adult Medicine. Additionally, Black men reported the highest rates of smoking, which may preclude physical activity over time, he noted.

Physical activity for White men declined in their twenties and thirties and stabilized at around age 40. For White women, physical activity hovered around 380 exercise units, dipping in their thirties and remaining constant to age 60.

Rates of hypertension mirrored this declining physical activity. Approximately 80-to-90 percent of Black men and women had hypertension by age 60, compared with just below 70 percent for White men and 50 percent for White women.

"Results from randomized controlled trials and observational studies have shown that exercise lowers blood pressure, suggesting that it may be important to focus on exercise as a way to lower blood pressure in all adults as they approach middle age," said senior author Kirsten Bibbins-Domingo, MD, PhD, of the UCSF Department of Epidemiology and Biostatistics.

"Teenagers and those in their early twenties may be physically active but these patterns change with age. Our study suggests that maintaining physical activity during young adulthood -- at higher levels than previously recommended -- may be particularly important."

More Exercise from Youth to Midlife Offers Best Protection Against Hypertension

When researchers looked at the 17.9 percent of participants who had moderate exercise for at least five hours a week during early adulthood -- double the recommended minimum -- they found that the likelihood of developing hypertension was 18 percent lower than for those who exercised less than five hours a week. The likelihood was even lower for the 11.7 percent of participants who maintained their exercise habits until age 60.

Patients should be asked about physical activity in the same way as they are routinely checked for blood pressure, glucose and lipid profiles, obesity and smoking, Nagata said, and intervention programs should be held at schools, colleges, churches, workplaces and community organizations. Black women have high rates of obesity and smoking, and low rates of physical activity, he said, and should be an important group for targeted intervention.

"Nearly half of our participants in young adulthood had suboptimal levels of physical activity, which was significantly associated with the onset of hypertension, indicating that we need to raise the minimum standard for physical activity," Nagata said. "This might be especially the case after high school when opportunities for physical activity diminish as young adults transition to college, the workforce and parenthood, and leisure time is eroded."

https://www.sciencedaily.com/releases/2021/04/210415090724.htm

Exercise promotes healthy living and a healthy liver

April 12, 2021

Science Daily/University of Tsukuba

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder worldwide, affecting as much as a quarter of humanity. It is characterized by fat accumulation in liver cells and may progress to inflammation, cirrhosis and liver failure. Now, researchers at the University of Tsukuba reveal the positive effects, beyond the expected weight-loss benefit, of exercise on the liver.

NAFLD is associated with unhealthy behaviors such as overeating and a sedentary lifestyle. In Japan 41% of middle-aged men have NAFLD and 25% will progress to non-alcoholic steatohepatitis (NASH) and hepatic dysfunction.

Weight reduction is fundamental to NAFLD management. Unfortunately, achieving a targeted bodyweight without supervision is difficult, and maintaining this over time even more so. Hitherto, exercise was considered adjunctive to dietary restrictions for weight loss but the other benefits such as reduced hepatic steatosis (fatty change) and stiffness are being increasingly recognized. However, the underlying mechanisms remain unclear.

"We compared data from obese Japanese men with NAFLD on a 3-month exercise regimen with those on dietary restriction targeting weight loss," senior author Professor Junichi Shoda explains. "We tracked hepatic parameters, reduction in adipose tissue, increase in muscle strength, reductions in inflammation and oxidative stress, changes in organokine concentrations, and expression of target genes of Nrf2, an oxidative stress sensor."

The researchers found that exercise preserved muscle mass better, though with modest decrease of body and fat mass. Remarkably, ultrasound elastography revealed that the exercise regimen reduced liver steatosis by an additional 9.5%, liver stiffness by an additional 6.8%, and the FibroScan-AST Score (a measure of liver fibrosis) by an additional 16.4% over the weight-loss regimen.

Additionally, the exercise regimen altered the circulating concentrations of specific organokines and apparently induced anti-inflammatory and anti-oxidative stress responses through activation of the Nrf2 (nuclear factor E2-related factor 2), an oxidative stress sensor. It also enhanced the phagocytic capacity of Kupffer cells which help maintain liver function.

Professor Shoda explains the relevance of their findings. "Our research shows how exercise prevents liver steatosis and fibrosis in NAFLD and clarifies that this benefit is compounded by preservation of muscle mass and is independent of weight changes. Patients on exercise regimens may become demotivated and drop out if they do not experience significant weight loss. Therefore, moderate to vigorous intensity exercise should be integrated in all NAFLD therapeutic regimens, and patients at risk for NASH should be encouraged to persevere with moderate to high intensity exercise regardless of whether or not they lose weight."

https://www.sciencedaily.com/releases/2021/04/210412101923.htm

People want to improve mental health by exercising, but stress and anxiety get in the way

April 12, 2021

Science Daily/McMaster University

New research from McMaster University suggests the pandemic has created a paradox where mental health has become both a motivator for and a barrier to physical activity.

People want to be active to improve their mental health but find it difficult to exercise due to stress and anxiety, say the researchers who surveyed more than 1,600 subjects in an effort to understand how and why mental health, physical activity and sedentary behavior have changed throughout the course of the pandemic.

The results are outlined in the journal PLOS ONE.

"Maintaining a regular exercise program is difficult at the best of times and the conditions surrounding the COVID-19 pandemic may be making it even more difficult," says Jennifer Heisz, lead author of the study and an associate professor in the Department of Kinesiology at McMaster.

"Even though exercise comes with the promise of reducing anxiety, many respondents felt too anxious to exercise. Likewise, although exercise reduces depression, respondents who were more depressed were less motivated to get active, and lack of motivation is a symptom of depression," she says.

Respondents reported higher psychological stress and moderate levels of anxiety and depression triggered by the pandemic. At the same time, aerobic activity was down about 20 minutes per week, strength training down roughly 30 minutes per week, and sedentary time was up about 30 minutes per day compared to six months prior to the pandemic.

Those who reported the greatest declines in physical activity also experienced the worst mental health outcomes, the researchers reported, while respondents who maintained their physical activity levels fared much better mentally.

Researchers also found economic disparities played a role, particularly among younger adults.

"Just like other aspects of the pandemic, some demographics are hit harder than others and here it is people with lower income who are struggling to meet their physical activity goals," says Maryam Marashi, a graduate student in the Department of Kinesiology and co-lead author of the study. "It is plausible that younger adults who typically work longer hours and earn less are lacking both time and space which is taking a toll."

After analysing the data, the researchers designed an evidence-based toolkit which includes the following advice to get active:

• Adopt a mindset: Some exercise is better than none.

• Lower exercise intensity if feeling anxious.

• Move a little every day.

• Break up sedentary time with standing or movement breaks.

• Plan your workouts like appointments by blocking off the time in your calendar.

"Our results point to the need for additional psychological supports to help people maintain their physical activity levels during stressful times in order to minimize the burden of the pandemic and prevent the development of a mental health crisis," says Heisz.

https://www.sciencedaily.com/releases/2021/04/210412121216.htm

Physical inactivity linked to more severe COVID-19 infection and death

Surpassed only by advanced age and organ transplant as a risk factor, large study shows

April 13, 2021

Science Daily/BMJ

Physical inactivity is linked to more severe COVID-19 infection and a heightened risk of dying from the disease, finds a large US study published online in the British Journal of Sports Medicine.

Patients with COVID-19 who were consistently inactive during the 2 years preceding the pandemic were more likely to be admitted to hospital, to require intensive care, and to die than were patients who had consistently met physical activity guidelines, the findings show.

As a risk factor for severe disease, physical inactivity was surpassed only by advanced age and a history of organ transplant.

Several risk factors for severe COVID-19 infection have been identified, including advanced age, male sex, and certain underlying medical conditions, such as diabetes, obesity, and cardiovascular disease.

But physical inactivity is not one of them, even though it is a well known contributory risk factor for several long term conditions, including those associated with severe COVID-19, point out the researchers.

To explore its potential impact on the severity of the infection, including hospital admission rates, need for intensive care, and death, the researchers compared these outcomes in 48,440 adults with confirmed COVID-19 infection between January and October 2020.

The patients' average age was 47; nearly two thirds were women (62%). Their average weight (BMI) was 31, which is classified as obese.

Around half had no underlying conditions, including diabetes, COPD, cardiovascular disease, kidney disease, and cancer; nearly 1 in 5 (18%) had only one; and almost a third (32%) had two or more.

All of them had reported their level of regular physical activity at least three times between March 2018 and March 2020 at outpatient clinics. This was classified as consistently inactive (0-10 mins/week); some activity (11-149 mins/week); or consistently meeting physical activity guidelines (150+ mins/week).

Some 7% were consistently meeting physical activity guidelines;15% were consistently inactive, with the remainder reporting some activity.

White patients were most likely to consistently meet physical activity guidelines (10%), followed by Asian patients (7%), Hispanic patients (6%) and African-American patients (5%).

Some 9% of the total were admitted to hospital; around 3% required intensive care; and 2% died. Consistently meeting physical activity guidelines was strongly associated with a reduced risk of these outcomes.

After taking account of potentially influential factors, such as race, age, and underlying medical conditions, patients with COVID-19 who were consistently physically inactive were more than twice as likely to be admitted to hospital as those who clocked up 150+ minutes of physical activity every week.

They were also 73% more likely to require intensive care, and 2.5 times more likely to die of the infection.

And patients who were consistently inactive were also 20% more likely to be admitted to hospital, 10% more likely to require intensive care, and 32% more likely to die of their infection than were patients who were doing some physical activity regularly.

This is an observational study, and as such, can't establish cause. The study also relied on patients' own assessments of their physical activity. Nor was there any measure of exercise intensity beyond the threshold of 'moderate to strenuous exercise' (such as a brisk walk).

But the study was large and ethnically diverse. And the researchers point out: "It is notable that being consistently inactive was a stronger risk factor for severe COVID-19 outcomes than any of the underlying medical conditions and risk factors identified by [The Centers for Disease Control] except for age and a history of organ transplant.

"In fact, physical inactivity was the strongest risk factor across all outcomes, compared with the commonly cited modifiable risk factors, including smoking, obesity, diabetes, hypertension [high blood pressure], cardiovascular disease and cancer."

They conclude: "We recommend that public health authorities inform all populations that short of vaccination and following public health safety guidelines such as social distancing and mask use, engaging in regular [physical activity] may be the single most important action individuals can take to prevent severe COVID-19 and its complications, including death.

"This message is especially important given the increased barriers to achieving regular [physical activity] during lockdowns and other pandemic restrictions."

https://www.sciencedaily.com/releases/2021/04/210413194036.htm

Leisure physical activity is linked with health benefits but work activity is not

April 8, 2021

Science Daily/European Society of Cardiology

The first large study showing that leisure time physical activity and occupational physical activity have opposite, and independent, associations with cardiovascular disease risk and longevity is published today in European Heart Journal, a journal of the European Society of Cardiology (ESC).

"We adjusted for multiple factors in our analysis, indicating that the relationships were not explained by lifestyle, health conditions or socioeconomic status," said study author Professor Andreas Holtermann of the National Research Centre for the Working Environment, Copenhagen, Denmark.

The World Health Organization (WHO) recommends physical activity during both recreation and work to improve health.* Previous studies have suggested that occupational activity is related to an increased risk for heart disease and mortality but have been too small to fully explain whether this was due to the manual work or because employees had unhealthy lifestyles or low socioeconomic status (e.g. low level of education).

This study included 104,046 women and men aged 20-100 years from the Copenhagen General Population Study with baseline measurements in 2003-2014. Participants completed questionnaires about activity during leisure and employment and were categorised as low, moderate, high, or very high activity for each.

During a median follow-up of 10 years, there were 9,846 (9.5%) deaths from all causes and 7,913 (7.6%) major adverse cardiovascular events (MACE, defined as fatal and nonfatal myocardial infarction, fatal and non-fatal stroke, and other coronary death).

Compared to low leisure time physical activity, after adjustment for age, sex, lifestyle, health, and education, moderate, high, and very high activity were associated with 26%, 41%, and 40% reduced risks of early death, respectively. In contrast, compared to low work activity, high and very high activity were associated with 13% and 27% increased risks of death, respectively.

Similarly, after adjustments, compared to low leisure activity, moderate, high, and very high levels of leisure activity were associated with 14%, 23%, and 15% reduced risks of MACE, respectively. Compared to low work activity, high and very high levels were associated with 15% and 35% increased risks of MACE, respectively.

Professor Holtermann said: "Many people with manual jobs believe they get fit and healthy by their physical activity at work and therefore can relax when they get home. Unfortunately, our results suggest that this is not the case. And while these workers could benefit from leisure physical activity, after walking 10,000 steps while cleaning or standing seven hours in a production line, people tend to feel tired so that's a barrier."

While the study did not investigate the reasons for the opposite associations for occupational and leisure time physical activity, Professor Holtermann said: "A brisk 30-minute walk will benefit your health by raising your heart rate and improving your cardiorespiratory fitness, while work activity often does not sufficiently increase heart rate to improve fitness. In addition, work involving lifting for several hours a day increases blood pressure for many hours, which is linked with heart disease risk, while short bursts of intense physical activity during leisure raises blood pressure only briefly."

Professor Holtermann's vision is to re-organise occupational activity so that it mimics the beneficial aspects of leisure exercise. Several approaches are being piloted, such as rotating between workstations on a production line so that employees do a "healthy mixture" of sitting, standing, and lifting during a shift. In another study, childcare workers play games together with children, instead of observing, so that both get their heart rate up and increase fitness. "We are trying to vary the tasks, give recovery time, or raise heart rate so there is a fitness and health benefit," he said.

Professor Holtermann concluded: "Societies need adults with sufficient health and fitness to work longer since the retirement age is increasing. We need to find ways to make active work good for health."

https://www.sciencedaily.com/releases/2021/04/210408212952.htm

Exercise, healthy diet in midlife may prevent serious health conditions in senior years

March 31, 2021

Science Daily/American Heart Association

Following a routine of regular physical activity combined with a diet including fruits, vegetables and other healthy foods may be key to middle-aged adults achieving optimal cardiometabolic health later in life, according to new research using data from the Framingham Heart Study published today in the Journal of the American Heart Association, an open access journal of the American Heart Association.

Cardiometabolic health risk factors include the metabolic syndrome, a cluster of disorders such as excess fat around the waist, insulin resistance and high blood pressure. Presence of the metabolic syndrome may increase the risk of developing heart disease, stroke and Type 2 diabetes.

Researchers noted it has been unclear whether adherence to both the U.S. Department of Health and Human Services' 2018 Physical Activity Guidelines for Americans and their 2015-2020 Dietary Guidelines for Americans -- as opposed to only one of the two -- in midlife confers the most favorable cardiometabolic health outcomes later in life. The physical activity guidelines recommend that adults achieve at least 150 minutes of moderate or 75 minutes of vigorous physical activity per week, such as walking or swimming. The dietary guidelines, which were updated in January 2021, offer suggestions for healthy eating patterns, nutritional targets and dietary limits.

In an analysis of data from participants of the Framingham Heart Study, which began more than 70 years ago in Framingham, Massachusetts, investigators examined data from 2,379 adults ages 18 and older and their adherence to the two guidelines. They observed that meeting a combination of the two recommendations during midlife was associated with lower odds of metabolic syndrome and developing serious health conditions as participants aged in their senior years in 2016-2019 examinations.

"Health care professionals could use these findings to further promote and emphasize to their patients the benefits of a healthy diet and a regular exercise schedule to avoid the development of numerous chronic health conditions in the present and in later life," said corresponding author Vanessa Xanthakis, Ph.D., FAHA, assistant professor of medicine and biostatistics in the Section of Preventive Medicine and Epidemiology at Boston University School of Medicine in Boston. "The earlier people make these lifestyle changes, the more likely they will be to lower their risk of cardiovascular-associated diseases later in life."

Study participants were selected from the third generation of the Framingham Heart Study. Participants (average age 47, 54% women) were examined between 2008 and 2011. Researchers evaluated physical activity using a specialized device known as an omnidirectional accelerometer. The device, which tracks sedentary and physical activity, was worn on the participant's hip for eight days. Researchers also collected dietary information from food frequency questionnaires to measure the kinds and levels of food and nutrients consumed.

In this investigation, researchers observed that among all participants, 28% met recommendations of both the physical activity and dietary guidelines, while 47% achieved the recommendations in only one of the guidelines. Researchers also observed that:

• participants who followed the physical activity recommendations alone had 51% lower odds of metabolic syndrome;

• participants who adhered to the dietary guidelines alone had 33% lower odds; and

• participants who followed both guidelines had 65% lower odds of developing metabolic syndrome.

"It is noteworthy that we observed a dose-response association of adherence to diet and physical activity guidelines with risk of cardiometabolic disease later in life," Xanthakis said. "Participants who met the physical activity guidelines had progressively lower risk of cardiometabolic disease as they increased adherence to the dietary guidelines."

All study participants were white adults, therefore, the findings cannot be generalized to people in other racial or ethnic groups. Additional studies with a multiethnic participant sample are needed, researchers said.

https://www.sciencedaily.com/releases/2021/03/210331085852.htm

Air pollution and physical exercise: When to do more or less

March 29, 2021

Science Daily/European Society of Cardiology

Physical activity is important in preventing heart and blood vessel disease in young people so long as they don't undertake very strenuous activity on days when air pollution levels are high, according to a nationwide study of nearly 1.5 million people published today (Tuesday) in the European Heart Journal.

Until now, little has been known about the trade-offs between the health benefits of physical activity taking place outdoors and the potentially harmful effects of air pollution. Previous research by the authors of the current study had investigated the question in middle-aged people at a single point in time, but this is the first time that it has been investigated in people aged between 20-39 years over a period of several years. In addition, the researchers wanted to see what happens when people increase or decrease their physical activity over time.

The researchers from Seoul National University College of Medicine (South Korea), led by Professor Sang Min Park, looked at information from the National Health Insurance Service (NHIS) in South Korea for 1,469,972 young Koreans living in cities, who underwent two consecutive health examinations during two screening periods: 2009-2010 and 2011-2012. They followed up the participants from January 2013 to December 2018.

At each health check-up the participants completed a questionnaire asking about their physical activity in the past seven days and this information was converted into units of metabolic equivalent task (MET) minutes per week (MET-mins/week). The participants were divided into four groups: 0, 1-499, 500-999 and 1000 or more MET-mins/week. European Society of Cardiology guidelines recommend people should try to do 500-999 MET-mins/week and this can be achieved by, for example, running, cycling or hiking for 15-30 minutes five times a week, or brisk walking, doubles tennis or slow cycling for 30-60 minutes five times a week. [1]

The researchers used data from the National Ambient Air Monitoring System in South Korea to calculate annual average levels of air pollution, in particular the levels of small particulate matter that are less than or equal to 10 or 2.5 microns in diameter, known as PM10 and PM2.5 [2]. The amount of exposure to air pollution was categorised at two levels: low to moderate (less than 49.92 and 26.43 micrograms per cubic metre, μm/m3, for PM10 and PM2.5 respectively), and high (49.92 and 26.46 μm/m3 or more, respectively). [2]

Dr Seong Rae Kim, first author of the paper, said: "We found that in young adults aged 20-39 years old, the risk of cardiovascular diseases, such as stroke and heart attack, increased as the amount of physical activity decreased between the two screening periods in the group with low levels of exposure to air pollution.

"However, in the group with high levels of exposure to air pollution, increasing the amount of physical activity to more than 1000 MET-min/week, which is more than internationally recommended levels for physical activity, could adversely affect cardiovascular health. This is an important result suggesting that, unlike middle-aged people over 40, excessive physical activity may not always be beneficial for cardiovascular health in younger adults when they are exposed to high concentrations of air pollution."

He continued: "Ultimately, it is imperative that air pollution is improved at the national level in order to maximise the health benefits of exercising in young adults. These are people who tend to engage in physical activity more than other age groups while their physical ability is at its best. If air quality is not improved, this could result in the incidence of cardiovascular diseases actually increasing despite the health benefits gained from exercise."

The researchers adjusted their results to take account of factors that could affect them, such as age, sex, household income, body mass index, smoking and alcohol consumption. During the follow-up period there were 8706 cardiovascular events. Among people exposed to high levels of PM2.5 air pollution, those who increased their exercise from 0 to 1000 MET-min/week or more between the two screening periods had a 33% increased risk of cardiovascular disease during the follow-up period compared to those who were physically inactive and did not increase their exercise, although this result was slightly weaker than that needed to achieve statistical significance. This means an extra 108 people per 10,000 might develop cardiovascular disease during the follow-up period.

Among people exposed to low to moderate levels of PM2.5, those who increased their physical activity from none to 1000 MET-min/week or more had a 27% reduced risk of developing cardiovascular disease compared to those who remained inactive, although this result was also not quite statistically significant. This means 49 fewer people per 10,000 might develop cardiovascular disease during the follow-up period.

Dr Kim said: "These results are very close to statistical significance. In fact, a further analysis ... of our paper shows that statistical significance was achieved for increasing and decreasing amounts of physical activity."

For low to moderate levels of PM10 air pollution, there was a statistically significant 38% or 22% increased risk of cardiovascular disease among people who started off doing 1000 MET-min/week or more and then reduced their activity to none or to 1-499 MET min/week, respectively, compared to people who maintained the same high level of activity. These results were statistically significant and mean that 74 and 66 extra people per 10,000 respectively would develop cardiovascular problems during the follow-up period.

Professor Sang Min Park, who led the research, said: "Overall, our results show that physical activity, particularly at the level recommended by European Society of Cardiology guidelines, is associated with a lower risk of developing heart and blood vessel disease among young adults. However, when air pollution levels are high, exercising beyond the recommended amount may offset or even reverse the beneficial effects."

The study cannot show that air pollution causes the increased cardiovascular risk, only that it is associated with it. Other limitations are that there was no information on whether or not the exercise took place indoors or outdoors; participants may not have remembered correctly the amount of exercise they took in the seven days before they attended their screening interview, although this is unlikely; PM2.5 data were only measured in three major cities; and the researchers did not investigate the short-term effects of exposure to air pollution.

https://www.sciencedaily.com/releases/2021/03/210329200307.htm

Activity is good: Varied activity is better

March 29, 2021

Science Daily/University of Basel

The recommendations are clear: physical activity is good for mental health. But it also depends on how varied it is. That's what a new study by researchers at the University of Basel shows, pointing to one of the reasons why well-being suffers during the pandemic.

A walk in the morning, a jog in the evening or even just going out to buy groceries: activity helps the psyche. Many are trying to stay active during the pandemic despite mandatory home office and limited leisure activities. Others find that they are moving significantly less than before the pandemic because previous everyday activities are off-limits due to measures taken against the spread of Covid-19.

Against this backdrop, a study led by Professor Andrew Gloster of the University of Basel provides an indication of what impact restricted movement patterns might have. The results have been published in the journal BMC Psychiatry.

That exercise promotes not only physical but also mental health is known from various studies. However, these mostly focused on the influence of deliberate exercise programs. "In contrast, little was known about whether everyday, naturally chosen movement patterns also influence mental health," Gloster explains.

To investigate this, he and researchers at the University Psychiatric Clinics in Basel collected GPS data from 106 patients with mental disorders who agreed to participate. For this purpose, the study participants were given extra smartphones that they carried with them for a week. This allowed the researchers to track their movements without interfering with the patients' daily routine. The research team then compared the movement data with surveys of the participants' well-being and symptoms of their mental illness.

The results showed that the more people moved and the more varied their movements, the greater their sense of well-being. However, no influence on the symptoms could be determined. "Our results suggest that activity alone is not enough to reduce symptoms of mental disorders, but can at least improve subjective well-being," Gloster elaborates.

"Although the data were collected before the pandemic, the results are also relevant in light of the limitations during the coronavirus crisis," he adds. Because many social and recreational activities were discontinued during that time, many people's physical activity patterns also likely became more monotonous. Various studies by research groups at the University of Basel have been able to show that the pandemic took a toll on the psyche of the population. The results of the team led by Gloster suggest that the restricted movement patterns could also play a role in this.

https://www.sciencedaily.com/releases/2021/03/210329122450.htm

More protein doesn't mean more strength in resistance-trained middle-aged adults

March 25, 2021

Science Daily/University of Illinois at Urbana-Champaign, News Bureau

A 10-week muscle-building and dietary program involving 50 middle-aged adults found no evidence that eating a high-protein diet increased strength or muscle mass more than consuming a moderate amount of protein while training. The intervention involved a standard strength-training protocol with sessions three times per week. None of the participants had previous weightlifting experience.

Published in the American Journal of Physiology: Endocrinology and Metabolism, the study is one of the most comprehensive investigations of the health effects of diet and resistance training in middle-aged adults, the researchers say. Participants were 40-64 years of age.

The team assessed participants' strength, lean-body mass, blood pressure, glucose tolerance and several other health measures before and after the program. They randomized participants into moderate- and high-protein diet groups. To standardize protein intake, the researchers fed each person a freshly cooked, minced beef steak and carbohydrate beverage after every training session. They also sent participants home with an isolated-protein drink to be consumed every evening throughout the 10 weeks of the study.

"The moderate-protein group consumed about 1.2 grams of protein per kilogram of body weight per day, and the high-protein group consumed roughly 1.6 grams per kilogram per day," said Colleen McKenna, a graduate student in the division of nutritional sciences and registered dietician at the University of Illinois Urbana-Champaign who led the study with U. of I. kinesiology and community health professor Nicholas Burd. The team kept calories equivalent in the meals provided to the two groups with additions of beef tallow and dextrose.

The study subjects kept food diaries and McKenna counseled them every other week about their eating habits and protein intake.

In an effort led by U. of I. food science and human nutrition professor Hannah Holscher, the team also analyzed gut microbes in fecal samples collected at the beginning of the intervention, after the first week -- during which participants adjusted to the new diet but did not engage in physical training -- and at the end of the 10 weeks. Previous studies have found that diet alone or endurance exercise alone can alter the composition of microbes in the digestive tract.

"The public health messaging has been that Americans need more protein in their diet, and this extra protein is supposed to help our muscles grow bigger and stronger," Burd said. "Middle age is a bit unique in that as we get older, we lose muscle and, by default, we lose strength. We want to learn how to maximize strength so that as we get older, we're better protected and can ultimately remain active in family and community life."

The American Food and Nutrition Board recommends that adults get 0.8 grams of protein per kilogram of body weight per day to avoid developing a protein deficiency. The team tried to limit protein consumption in the moderate-protein group to the Recommended Daily Allowance, but their food diaries revealed those participants were consuming, on average, 1.1 to 1.2 grams of protein per kilogram of body weight per day. Those in the high-protein group ate about 1.6 grams of protein per kilogram per day -- twice the recommended amount.

Burd and his colleagues hypothesized that getting one's protein from a high-quality source like beef and consuming significantly more protein than the RDA would aid in muscle growth and strength in middle-aged adults engaged in resistance training. But at the end of the 10 weeks, the team saw no significant differences between the groups. Their gains in strength, their body fat, lean body mass, glucose tolerance, kidney function, bone density and other "biomarkers" of health were roughly the same.

The only potentially negative change researchers recorded between the groups involved alterations to the population of microbes that inhabit the gut. After one week on the diet, those in the high-protein group saw changes in the abundance of some gut microbes that previous studies have linked to negative health outcomes. Burd and his colleagues found that their strength-training intervention reversed some of these changes, increasing beneficial microbes and reducing the abundance of potentially harmful ones.

"We found that high protein intake does not further increase gains in strength or affect body composition," Burd said. "It didn't increase lean mass more than eating a moderate amount of protein. We didn't see more fat loss, and body composition was the same between the groups. They got the gain in weight, but that weight gain was namely from lean-body-mass gain."

Burd said the finding makes him question the push to increase protein intake beyond 0.8-1.1 grams per kilogram of body weight, at least in middle-aged weightlifters consuming high-quality animal-based protein on a regular basis.

McKenna said the team's multidisciplinary approach and in-depth tracking of participants' dietary habits outside the laboratory makes it easier to understand the findings and apply them to daily life.

"We have recommendations for healthy eating and we have recommendations for how you should exercise, but very little research looks at how the two together impact our health," she said. The study team included exercise physiologists, registered dietitians and experts on gut microbiology.

"This allowed us to address every aspect of the intervention in the way it should be addressed," McKenna said. "We're honoring the complexity of human health with the complexity of our research."

https://www.sciencedaily.com/releases/2021/03/210325101256.htm

Exercise boosts blood flow to the brain

The results add to growing evidence that exercise programs may help older adults slow the onset of memory loss and dementia

March 23, 2021

Science Daily/UT Southwestern Medical Center

It's not just your legs and heart that get a workout when you walk briskly; exercise affects your brain as well. A new study by researchers at UT Southwestern shows that when older adults with mild memory loss followed an exercise program for a year, the blood flow to their brains increased. The results were published online today in the Journal of Alzheimer's Disease.

"This is part of a growing body of evidence linking exercise with brain health," says study leader Rong Zhang, Ph.D., professor of neurology at UTSW. "We've shown for the first time in a randomized trial in these older adults that exercise gets more blood flowing to your brain."

As many as one-fifth of people age 65 and older have some level of mild cognitive impairment (MCI) -- slight changes to the brain that affect memory, decision-making, or reasoning skills. In many cases, MCI progresses to dementia, including Alzheimer's disease.

Scientists have previously shown that lower-than-usual levels of blood flow to the brain, and stiffer blood vessels leading to the brain, are associated with MCI and dementia. Studies have also suggested that regular aerobic exercise may help improve cognition and memory in healthy older adults. However, scientists have not established whether there is a direct link between exercise, stiffer blood vessels, and brain blood flow.

"There is still a lot we don't know about the effects of exercise on cognitive decline later in life," says C. Munro Cullum, Ph.D., professor of psychiatry at UTSW and co-senior author of the study. "MCI and dementia are likely to be influenced by a complex interplay of many factors, and we think that, at least for some people, exercise is one of those factors."

In the study, Zhang, Cullum, and their colleagues followed 70 men and women aged 55 to 80 who had been diagnosed with MCI. Participants underwent cognitive exams, fitness tests, and brain magnetic resonance imaging (MRI) scans. Then they were randomly assigned to either follow a moderate aerobic exercise program or a stretching program for one year. The exercise program involved three to five exercise sessions a week, each with 30-40 minutes of moderate exercise such as a brisk walk.

In both programs, exercise physiologists supervised participants for the first four to six weeks, then had the patients record their exercises and wear a heart rate monitor during exercise.

Forty-eight study participants -- 29 in the stretching group and 19 in the aerobic exercise group -- completed the full year of training and returned for follow-up tests. Among them, those who performed aerobic exercise showed decreased stiffness of blood vessels in their neck and increased overall blood flow to the brain. The more their oxygen consumption (one marker of aerobic fitness) increased, the greater the changes to the blood vessel stiffness and brain blood flow. Changes in these measurements were not found among people who followed the stretching program.

While the study didn't find any significant changes in memory or other cognitive function, the researchers say that may be because of the small size or short length of the trial. Changes to blood flow could precede changes to cognition, they say. They're already carrying out a larger two-year study, Risk Reduction for Alzheimer's Disease (rrAD), that further investigates the link between exercise and cognitive decline.

"There are likely some people who benefit more from exercise than others," says Cullum. "But with the sample size in this study, it was hard to analyze subgroups of people to make those conclusions."

Still, the data are important to help explain the effects of exercise on the brain and why it can be beneficial, say Zhang and Cullum, who are members of the Peter O'Donnell Jr. Brain Institute.

"Having physiological findings like this can also be useful for physicians when they talk to their patients about the benefits of exercise," says Zhang. "We now know, based on a randomized, controlled trial, that exercise can increase blood flow to the brain, which is a good thing."

https://www.sciencedaily.com/releases/2021/03/210323131213.htm

A strong coffee half an hour before exercising increases fat-burning

Drinking a strong coffee half an hour before exercising increases fat-burning

March 22, 2021

Science Daily/University of Granada

Scientists from the Department of Physiology of the University of Granada (UGR) have shown that caffeine (about 3 mg/kg, the equivalent of a strong coffee) ingested half an hour before aerobic exercise significantly increases the rate of fat-burning. They also found that if the exercise is performed in the afternoon, the effects of the caffeine are more marked than in the morning.

In their study, published in the Journal of the International Society of Sports Nutrition, the researchers aimed to determine whether caffeine -- one of the most commonly-consumed ergogenic substances in the world to improve sports performance -- actually does increase oxidation or "burning" of fat during exercise. Despite the fact that its consumption in the form of supplements is very common, the scientific evidence for its beneficial claims is scarce.

"The recommendation to exercise on an empty stomach in the morning to increase fat oxidation is commonplace. However, this recommendation may be lacking a scientific basis, as it is unknown whether this increase is due to exercising in the morning or due to going without food for a longer period of time," explains the lead author of this research, Francisco José Amaro-Gahete of the UGR's Department of Physiology.

A total of 15 men (mean age, 32) participated in the research, completing an exercise test four times at seven-day intervals. Subjects ingested 3 mg/kg of caffeine or a placebo at 8am and 5pm (each subject completed the tests in all four conditions in a random order). The conditions prior to each exercise test (hours elapsed since last meal, physical exercise, or consumption of stimulant substances) were strictly standardized, and fat oxidation during exercise was calculated accordingly.

Maximum fat oxidation 

"The results of our study showed that acute caffeine ingestion 30 minutes before performing an aerobic exercise test increased maximum fat oxidation during exercise regardless of the time of day," explains Francisco J. Amaro. The existence of a diurnal variation in fat oxidation during exercise was confirmed, the values being higher in the afternoon than in the morning for equal hours of fasting.

These results also show that caffeine increases fat oxidation during morning exercise in a similar way to that observed without caffeine intake in the afternoon.

In summary, the findings of this study suggest that the combination of acute caffeine intake and aerobic exercise performed at moderate intensity in the afternoon provides the optimal scenario for people seeking to increase fat-burning during physical exercise.

https://www.sciencedaily.com/releases/2021/03/210322175042.htm

Cells burn more calories after just one bout of moderate aerobic exercise

March 22, 2021

Science Daily/Oregon State University

In a recent study testing the effects of exercise on overall metabolism, researchers at Oregon State University found that even a single session of moderate aerobic exercise makes a difference in the cells of otherwise sedentary people.

Mitochondria are the part of the cell responsible for the biological process of respiration, which turns fuels such as sugars and fats into energy, so the researchers focused only on mitochondria function.

"What we found is that, regardless of what fuel the mitochondria were using, there were mild increases in the ability to burn off the fuels," said Matt Robinson, lead author on the study and an assistant professor in the College of Public Health and Human Sciences.

OSU researchers recruited participants who do not follow a regular exercise routine and had them ride a stationary bike for an hour at a moderate intensity. They biopsied their muscles 15 minutes later to test how efficient the mitochondria were after the exercise was completed and compared those results with a resting day.

Post-exercise, study participants' mitochondria burned 12-13% more fat-based fuel and 14-17% more sugar-based fuel. While the effects were not drastic, they were consistent, Robinson said.

"It's pretty remarkable that even after just one hour of exercise, these people were able to burn off a little more fuel," he said.

Previous research in the field has long established that regular exercise creates lasting change in people's metabolism, making their bodies burn more energy even when they're not working out.

Prior studies have looked at highly trained or athletic people, but Robinson's team wanted to look specifically at singular bouts of exercise in people who were generally active and disease-free but who did not have structured exercise regimes. These people were on the lower end of fitness, which is associated with low mitochondrial abundance and energy production. Participants were monitored while working out at approximately 65% of their maximal effort, where they could keep up the cycling pace for an hour or more and still comfortably carry on a conversation.

Robinson said they're hoping these results help break down the mental barrier of people thinking they need to be elite athletes for exercise to make an impact on their health.

"From a big picture health perspective, it's very encouraging for people to realize that you can get health benefits from a single session of exercise," Robinson said. "We're trying to encourage people, 'You did one, why don't you try to do two? Let's do three.'

"We know that exercise is good for you, in general. But those benefits of that single bout of exercise seem to fade away after a day or two. You get the long-term benefits when you do that exercise again and again and you make it a regular habit."

In this study, Robinson's research team focused narrowly on mitochondria to find out how big a role mitochondria play in the overall function of muscle metabolism. Other studies are looking at changes in blood flow to the muscle and how the muscle metabolizes fats versus sugars.

From a disease perspective, Robinson said it's clear that obesity and diabetes involve impairments in metabolism. Physiologically, when the body undergoes exercise, sugars tend to be burned off first while fats are stored, but in cases of diabetes and obesity, there is some dysregulation in metabolism that causes the body to not be able to switch between the two types of fuel.

Exercise can help reset that system, he said.

"Since those get burned off in the mitochondria, our hope is that with exercise, we could increase the mitochondria and then improve how the body burns off fats and sugars," he said.

https://www.sciencedaily.com/releases/2021/03/210322085520.htm

Green leafy vegetables essential for muscle strength

March 24, 2021

Science Daily/Edith Cowan University

Eating just one cup of leafy green vegetables every day could boost muscle function, according to new Edith Cowan University (ECU) research.

The study, published today in the Journal of Nutrition, found that people who consumed a nitrate-rich diet, predominantly from vegetables, had significantly better muscle function of their lower limbs.

Poor muscle function is linked to greater risk of falls and fractures and is considered a key indicator of general health and wellbeing.

Researchers examined data from 3,759 Australians taking part in Melbourne's Baker Heart and Diabetes Institute AusDiab study over a 12-year period. They found those with the highest regular nitrate consumption had 11 per cent stronger lower limb strength than those with the lowest nitrate intake. Up to 4 per cent faster walking speeds were also recorded.

Lead researcher Dr Marc Sim from ECU's Institute for Nutrition Research said the findings reveal important evidence for the role diet plays in overall health.

"Our study has shown that diets high in nitrate-rich vegetables may bolster your muscle strength independently of any physical activity," he said.

"Nevertheless, to optimise muscle function we propose that a balanced diet rich in green leafy vegetables in combination with regular exercise, including weight training, is ideal."

Muscle function is vital for maintaining good overall health, especially bone strength later in life.

"With around one in three Australians aged over 65 suffering a fall each year, it's important to find ways of preventing these events and their potentially serious consequences," said Dr Sim.

Go for green

While leafy greens may be some of our least favourite vegetables, they could be the most important, according to Dr Sim.

The research found nitrate-rich vegetables, such as lettuce, spinach, kale and even beetroot, provided the greatest health benefits.

"Less than one in ten Australians eat the recommended five to six serves of vegetables per day," Dr Sim said.

"We should be eating a variety of vegetables every day, with at least one of those serves being leafy greens to gain a range of positive health benefits for the musculoskeletal and cardiovascular system."

"It's also better to eat nitrate-rich vegetables as part of a healthy diet rather than taking supplements. Green leafy vegetables provide a whole range of essential vitamins and minerals critical for health."

Building knowledge

The study, a collaboration with Deakin University's Institute of Physical Activity and Nutrition and the Baker Heart and Diabetes Institute, builds on Dr Sim's previous research into nitrate and muscle function in older women.

It also adds to growing evidence linking vegetables with cardiovascular health, including a recent ECU study into cruciferous vegetables and blood vessel health.

Dr Sim said the next step of his research will be exploring strategies to increase leafy green vegetable consumption in the general population.

"We are currently recruiting for the MODEL Study, which examines how knowledge of disease can be used to prompt people in making long-term improvements to their diet and exercise," said Dr Sim.

https://www.sciencedaily.com/releases/2021/03/210324132309.htm