Researchers have found that greater grip strength in older women reduces mortality risk, regardless of weight change, suggesting that mobility and strength support should have more focus than weight loss in this group.
Grip strength and short physical performance battery (SPPB) are measures of physical functioning. Grip strength assesses strength of grip alone, whereas SPPB is a cumulative score considering three components: balance test, timed walk, and chair stands.
Previous studies have shown a link between increased grip strength and lower all-cause mortality. SPPB considers timed walk, balance test, and chair stands, and is associated with CVD risk in older women. However, studies of the effects of weight loss on grip strength which evaluated participants before and after weight loss interventions have shown inconsistent results.
In a study published in the Journal of the American Geriatrics Society, researchers followed 5039 older women for an average of 5.4 years. They found that loss of 5% or more body weight was associated with a 66% higher risk of dying. However, there was no association of weight gain with mortality.
The researchers also found that higher grip strength and better lower extremity functioning were associated with lower risks of death during follow-up, regardless of weight change.
“Our findings support increasing efforts to improve mobility and muscle strength in older women and less focus on long-term weight loss in this population,” said lead author Lisa Underland, DO, of Children’s Hospital at Montefiore.
Researchers at the University of Queensland have identified an exercise ‘sweet spot’ that reverses the cognitive decline in ageing mice, paving the way for human studies.
After more than a decade of research, the team led by Professor Perry Bartlett and Dr Dan Blackmore, the team found 35 days of voluntary physical exercise improved learning and memory. The findings were published in iScience.
“We tested the cognitive ability of elderly mice following defined periods of exercise and found an optimal period or ‘sweet spot’ that greatly improved their spatial learning,” Dr Blackmore said.
Additionally, the researchers also discovered how exercise improved learning – down to growth hormones.
“We found that growth hormone (GH) levels peaked during this time, and we’ve been able to demonstrate that artificially raising GH in sedentary mice also was also effective in improving their cognitive skills,” Dr Blackmore said
“We discovered GH stimulates the production of new neurons in the hippocampus – the region of the brain critically important to learning and memory.
“This is an important discovery for the thousands of Australians diagnosed with dementia every year.”
Dementia is the second leading cause of death of all Australians, and with no medical breakthrough the number of people with dementia is expected to increase to around 1.1 million by 2058.
Professor Bartlett said the findings add to the body of evidence showing that loss of cognitive function in old age is directly related to the diminished production of new neurons.
“It underlines the importance of being able to activate the neurogenic stem cells in the brain that we first identified 20 years ago,” Professor Bartlett said.
The team were able to explore how the production of new neurons changed the circuitry in the brain using Magnetic Resonance Imaging (MRI).
“Using MRI, we were able to study the brain following exercise, and for the first time identify the critical changes in the structure and functional circuitry of the hippocampus required for improved spatial learning,” Dr. Blackmore said.
Researchers have found that a mere ten minutes of running at moderate intensity boosts blood flow to thebilateral prefrontal cortex, improving cognitive function and mood. These findings, published in Scientific Reports, may contribute to the development of a wider range of treatment recommendations to benefit mental health.
Physical activity has many benefits as noted by a great body of evidence, such as the ability to lift mood, but in previous studies, cycling was often the form of exercise studied. However, running has always played an important role in the well-being of humans. Human running’s unique form and efficiency, which includes the ability to sustain this form of exertion (ie, by jogging as opposed to sprinting), and human evolutionary success are closely linked.
Despite this fact, researchers had not yet looked closely at the effects of running on brain regions that control mood and executive functions. “Given the extent of executive control required in coordinating balance, movement, and propulsion during running, it is logical that there would be increased neuronal activation in the prefrontal cortex and that other functions in this region would benefit from this increase in brain resources,” explained senior author Professor Hideaki Soya at the University of Tsukuba, Japan.
To test their hypothesis, the research team used the well-established Stroop Colour–Word Test and measured haemodynamic changes associated with brain activity while participants were engaged in each task. For example, in one task, incongruent information is shown, eg the word ‘red’ is written in green, and the participant must name the colour rather than read out the word. To do so, the brain must process both sets of information and inhibit the extraneous information. The Stroop interference effect was quantified by the difference in response times for this task and those for a simpler version of the task – stating the names of colour swatches.
The results show that, after ten minutes of moderate-intensity running, there was a significant reduction in Stroop interference effect time. Furthermore, bilateral prefrontal activation had significantly increased during the Stroop task and participants also reported being in a better mood. “This was supported by findings of coincident activations in the prefrontal cortical regions involved in mood regulation,” noted first author Chorphaka Damrongthai.
Given that many characteristics of the human prefrontal cortex are uniquely human, this study not only sheds light on the present benefits of running but also on the possible role that these benefits may have played in the evolutionary past of humans.
Researchers have found that exercise increases endocannabinoids, helping reduce inflammation and could potentially help treat certain conditions such as arthritis, cancer and heart disease.
A new study, published in Gut Microbes, found that exercise intervention in people with arthritis, in addition to reducing pain, also lowered the levels of inflammatory cytokines. It also increased levels of endocannabinoids, cannabis-like substances produced by the body. Interestingly, exercise caused these changes through an unusual mechanism: altering the gut microbes.
Exercise is known to reduce chronic inflammation, which is linked to a number of diseases including cancer, arthritis and heart disease. However, little is known as to exactly how exercise reduces inflammation.
Researchers tested 78 people with arthritis. Thirty-eight of them carried out 15 minutes of muscle strengthening exercises every day for six weeks, and 40 did nothing.
At the end of the study, those in the exercise intervention group had not only reduced their pain, but they also had more gut microbes that produce anti-inflammatory substances, lower levels of cytokines and higher levels of endocannabinoids.
The increase in endocannabinoids was strongly linked to changes in the gut microbes and anti-inflammatory substances produced by gut microbes called SCFAS. At least a third of the anti-inflammatory effects of the gut microbiome was attributable to the increase in endocannabinoids.
“Our study clearly shows that exercise increases the body’s own cannabis-type substances. Which can have a positive impact on many conditions. As interest in cannabidiol oil and other supplements increases, it is important to know that simple lifestyle interventions like exercise can modulate endocannabinoids,” said Doctor Amrita Vijay, a Research Fellow in the School of Medicine and first author of the paper
In an analysis of six global studies, investigators found no link between the amount and duration of physical activity with individuals’ risk of developing knee osteoarthritis.
The analysis, which is published in Arthritis & Rheumatology, included six global community-based studies which had a combined total of 5065 participants with and without knee osteoarthritis, who were followed for five to 12 years. “Knowing that the amount of physical activity and time spent doing it is not associated with the development of knee osteoarthritis is important evidence for both clinicians and the public who may need to consider this when prescribing physical activity for health,” explained co–lead author Thomas Perry, BSc, PhD, at the University of Oxford.
As a next step, it will be important to understand the role of injury and specific types of activity within this association, noted co–lead author Lucy S. Gates, PhD, University of Southampton, and co–senior author Maria Sanchez-Santos, University of Oxford.
In a small study, researchers found that exercise could help reduce sleep apnoea symptoms and improve brain function.
Sleep apnoea is characterised by loud snoring and disrupted breathing and is a risk factor for cardiovascular disease and cognitive decline. It is typically treated with continuous positive airway pressure, or CPAP, which is uncomfortable for patients and often not adhered to.
“Exercise training appears to be an attractive and adjunctive (add-on) non-pharmacological treatment,” said lead investigator Linda Massako Ueno-Pardi, an associate professor at the School of Arts, Science and Humanities at the University of São Paulo in Brazil. She also is a research collaborator at the university’s Heart Institute and Institute of Psychiatry, Faculty of Medicine.
Sleep apnoea is more common in men than women and becomes more prevalent as people age. According to a scientific statement by the American Heart Association, between 40% and 80% of people with cardiovascular disease have sleep apnoea. Cigarette smoking and type 2 diabetes are among the risk factors for sleep apnoea, as well as obesity, which narrows the airway when sleeping.
People with sleep apnoea have been shown to experience a decrease in brain glucose metabolism, which can impair cognitive function. The researchers sought to find out whether exercise could help correct that, building on a small 2019 study where aerobic activity improved brain glucose metabolism and executive functioning in Alzheimer’s patients.
The new study recruited 47 adults with moderate to severe obstructive sleep apnoea. Half did 60 minutes of supervised exercise three times a week for six months, and the other half were a control group.
Participants in both groups were given a series of tests to measure exercise capacity, brain glucose metabolism and cognitive function, including attention and executive function. Obstructive sleep apnoea symptom severity was measured, such as hypoxia.
At the end of six months, those in the exercise group showed an increased capacity for exercise; improvements in brain glucose metabolism; sleep apnoea symptom reduction; and a boost in cognitive function, including a 32% improvement in attention and executive function. The control group experienced no changes except a decline in brain glucose metabolism.
A “significant reduction” seen in the exercise group’s body fat may have improved sleep apnoea severity by decreasing body fat, especially around the airways.
In a small study, a year of exercise training helped to maintain or increase the youthful elasticity of the heart muscle among people in late middle age showing early signs of heart failure.
Published in Circulation, the research reinforces the notion that “exercise is medicine,” an important shift in approach, according to the researchers.
The study focused on heart failure with preserved ejection fraction, which is characterised by stiffening of the heart muscle and high pressures inside the heart during exercise. Once established, the condition is largely untreatable and causes fatigue, excess fluid in the lungs and legs, and shortness of breath.
“It is considered by some to be one of the most important virtually untreatable diseases in cardiovascular medicine,” said senior author Dr Benjamin Levine, professor of internal medicine at UT Southwestern and director of the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Dallas. “So, of course, if there are no therapies, then the most important thing to do is to figure out how to prevent it from happening in the first place.”
In previous studies, prolonged exercise training was shown to improve heart elasticity in younger people, but was ineffective for heart stiffness in people 65 and older. The researchers decided to see if committed exercise could improve heart stiffness in healthy, sedentary men and women ages 45 to 64.
The study recruited 31 participants who showed some thickening of the heart muscle and an increase in blood biomarkers associated with heart failure, even though they had no other symptoms such as shortness of breath.
Eleven were randomly assigned to a control group and prescribed a program of yoga, balance and strength training three times a week. The rest were assigned to an individually tailored exercise regimen that gradually ramped up until the participants were doing intensive aerobic interval training for at least 30 minutes at least twice a week, plus two to three moderate-intensity training sessions and one to two strength training sessions each week.
After one year, the group assigned vigorous exercise training showed a physiologically and statistically significant improvement in measures of cardiac stiffness and cardiorespiratory fitness, compared to no change in the control group.
The results suggest late middle age may be a “sweet spot” for using exercise to prevent heart failure with preserved ejection fraction, before the heart gets too stiff, Prof Levine said. He compared the heart muscle to an elastic band: a new one stretches easily and snaps right back.
“That’s a youthful cardiovascular system,” he said. “Now, stick it in a drawer and come back 30 years later—it doesn’t stretch, and it doesn’t snap back. And that’s one of the things that happens to the circulation, both the heart and the blood vessels as we age, particularly with sedentary aging.”
However, the study cannot determine if the participants will still go on to develop heart failure. This question will have to be addressed by larger studies. Furthermore, it is difficult for people to adhere to an exercise program, and the intensive intervention studied may be difficult and expensive to replicate on a large scale.
Stepping patterns become slower and more variable when a person is not comfortable with their environment, researchers have found.
The findings, published in PLoS One, shows that the perceived comfort of an environment, rather than it being natural or not, affects how people walk, with potential lessons for urban design.
Lead author Daria Burtan of Bristol’s School of Psychological Science said: “Measuring the changes of a person’s walking patterns through an environment allows us to understand their experienced comfort on a moment-to-moment basis.
“This is an important step toward being able to objectively quantify the impact of particular architectural designs on people’s wellbeing.”
Research has shown that spending time in green spaces such as parks helps improve attention spans, concentration and wellbeing, which can be shown by improvements in measured stepping patterns when walking in different environments.
Daria added: “As our cognitive faculties begin to decline in older age, the stepping patterns we make with our feet become slower and more variable, relative to when we are younger in the prime of our health. We found that the same thing happened when people walked toward images of urban and nature scenes they didn’t feel comfortable with – their stepping patterns became slower and more varied, relative to when they were looking at scenes they found comfortable and which they liked.
“Not only does this suggest that environments in which we feel comfortable and safe, place fewer processing demands on our brains; it demonstrates how measuring the real-time dynamics of our gait provides us with a powerful new tool for informing on the cognitive impacts of architecture and urban design.”
The researchers are now seeking to understand which psychological factors contribute to sensory discomfort.
Higher levels of physical activity and fewer hours sitting still have been linked with a lower risk of sleep apnoea in a new study.
Researchers studied information from three different databases. These databases had collected health information on men and women using tests and questionnaires over several years. In this study, researchers looked at cases of sleep apnoea that had been diagnosed by a doctor, the amount of physical activity a person completed each week and how much time a person sat still while watching TV or working.
Drawing on the database, the study found 8733 cases of sleep apnoea (6652 women, 2081 men). Across all three databases, it was found that higher levels of physical activity were linked to lower levels of sleep apnoea. Fewer hours of sitting while watching TV or while working was also linked with lower levels of sleep apnoea. The study also noted that there was a strong link between low levels of activity and long hours sitting in women, as well as those who were overweight or obese.
According to its authors, this is the largest study of its kind that looks at the link between sleep apnoea and physical activity and the number of hours sitting down. The findings support the benefits of maintaining an active lifestyle, and avoiding sitting for long periods of time, to help to reduce the risk of sleep apnoea.
If patients follow lifestyle advice and medications after a heart attack, it could add seven healthy years of life, according to a new study.
“Most heart attack patients remain at high risk of a second attack one year later,” explained study author Dr Tinka Van Trier of Amsterdam University Medical Centre. “Our study suggests that improving both lifestyles and medication use could lower this risk, with a gain in many years of life without a cardiovascular event.”
A previous study showed that 80–90% of the risk of a heart attack can be modified by managing factors such as smoking, unhealthy diet, abdominal obesity, inadequate physical activity, hypertension, diabetes and raised blood lipid levels. Two main strategies are used: lifestyle change and medication.
However, risk factors are rarely reduced sufficiently after a heart attack, even in programmes aiming to help patients improve their lifestyles and optimise their medication. Therefore, residual risk is high to very high in a large number of patients. Dr Van Trier said: “This study was conducted to quantify this residual risk and estimate the extent to which it could be lowered with optimal management.”
The study pooled data from 3230 patients, average age 61 and 24% women, that had a heart attack or received a stent or bypass surgery. At an average of one year after the cardiac event, 30% continued smoking, 79% were overweight, and 45% reported insufficient physical activity. Only 2% of attained treatment targets for blood pressure, LDL cholesterol, and glucose levels with 40% having hypertension and 65% having high LDL cholesterol. Preventative medication use was common: 87% used antithrombotic medications, 85% took lipid lowering drugs and 86% were on blood pressure lowering drugs.
The researchers calculated the lifetime risk of a heart attack, stroke, or death from cardiovascular disease and estimated changes in healthy years when lifestyle or medication was changed or optimised.
The estimated average residual lifetime risk for cardiovascular disease mortality was 54%. If all targets in the model were met, this risk would drop to 21%.
Dr Van Trier said: “The findings show that despite current efforts to reduce the likelihood of new events after a heart attack, there is considerable room for improvement. Our analysis suggests that the risk of another cardiovascular event could, on average, be halved if therapies were applied or intensified. For individual patients, this would translate into gaining an average of 7.5 event-free years.”
