Category: Exercise

Compression Garments Offer No Exercise Recovery Benefit

Man and woman about to sprint
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A meta-analysis of studies on the ability of compression garments, elastic clothing on the limbs or hips, to enhance muscle recovery after exercise found that they provide no recovery benefit. Rather, they should be used to help reduce injury, the reviewers suggest.

Use of compression garments has gained popularity over the last few decades because they are thought to enhance muscle recovery following exercise.

An international research team, led by assistant professor János Négyesi, conducted a review using a generic inverse variance model, which adjusts the weight of individual studies according to sample size, to more accurately assess the effects of compression garments than previous meta-analyses.

Contrary to results found in individual research, the meta-analytical evidence suggests that wearing a compression garment during or after training does not facilitate muscle recovery.

“Even data from our previous study supported the idea that such garments have the potential to reduce strength loss after a strenuous workout,” said Dr Négyesi. “However, when we synthesized the data of all relevant studies, we found no effect of compression garments on strength recovery – even when factoring in exercise type and when and where the compression garment is applied.”

The authors think this is a perfect example of contradictory outcomes from individual studies and meta-analytical evidence. Therefore, scientists should be careful when drawing direct conclusions from the results of their studies. Rather, meta-analyses using the most appropriate models can provide more precise and reliable results.

Overall, practitioners, athletes, coaches, and therapists should reconsider compression garments as a means of reducing the harmful effects of physical exercise on muscle strength and seek alternative methods.

The review appears in Sports Medicine.

Source: Tohoku University

Cutting Down on Sedentary Time Reduces Cardiovascular Risk

Feet in sports shoes
Source: Pixabay

Cutting down daily sedentary time can have a positive effect on the risk factors of cardiovascular disease and type 2 diabetes in as little as three months, according to a study published in the Journal of Science and Medicine in Sport. The study findings suggest that simply one hour less sitting daily and increasing light physical activity can help in the prevention of these diseases.

Regular exercise is well known to be beneficial in weight management and prevention of chronic diseases. However, many adults do not meet the weekly recommendation of 2.5 hours of moderate-intensity exercise, and the majority of the day is typically spent sitting.

In an intervention study, researchers investigated whether health benefits can be achieved by reducing daily sedentary time during a three-month intervention period. The research participants were sedentary and physically inactive working-age adults with an increased risk of type 2 diabetes and cardiovascular diseases.

The researchers compared two groups: the intervention group was guided to reduce their sitting time by one hour per day by increasing standing and light-intensity physical activity, while the control group was instructed to maintain their usual habits and sedentary lifestyle.

“What makes our research design unique is that sedentary time and physical activity of both groups were measured with accelerometers throughout the entire three-month period, whereas in earlier studies activity has typically been measured only for a few days at the beginning and end of the study period. This makes it possible to receive more information on the actual behaviour changes over a longer time period,” explained  Doctoral Candidate Taru Garthwaite from the University of Turku in Finland.

The intervention group reduced sedentary time by 50 minutes per day on average, mainly by increasing the amount of light- and moderate-intensity physical activity. Over the three-month period, the researchers observed benefits in health outcomes related to blood sugar regulation, insulin sensitivity and liver health in the intervention group.

“It is an encouraging thought that health benefits can be achieved by reducing the time spent sitting and increasing the amount of even light-intensity physical activity. For many, this may be an easier starting point than increasing actual exercise,” said Garthwaite.

People who do not meet the weekly physical activity recommendations atre the most likely to benefit the most from replacing sedentary time with light physical activity. However, reducing sedentary time is probably not enough in itself to prevent diseases if the person has several risk factors of diabetes and cardiovascular diseases.

Garthwaite stressed the encouraging nature of the findings: “Reducing the time spent sitting might still slow down the development of these diseases, but greater benefits can of course be gained by increasing the amount or intensity of physical activity in addition to sitting less.”

The researchers next aim to study how changes in daily activity and sedentary time affect energy metabolism and body composition in addition to the risk factors of diabetes and cardiovascular diseases over a six-month study period.

Source: University of Turku

When Dieting, High-intensity Exercise Might Combat Cravings

Tired woman after exercise
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Revealing another benefit of exercise for weight loss, results from a study published in Obesity showed that rats on a 30-day diet who exercised intensely were better able to resist cues for favoured, high-fat food pellets.

The experiment was designed to investigate a phenomenon called “incubation of craving”, where the longer a desired substance is denied, the harder it is to resist cue for it. The findings suggest that exercise modulated how hard the rats were willing to work for cues associated with the pellets, reflecting how much they craved them.

Though more researcher is needed, these findings show that exercise may shore up restraint when it comes to certain foods, explained corresponding author Travis Brown, a physiology and neuroscience researcher at Washington State University.

“A really important part of maintaining a diet is to have some brain power – the ability to say ‘no, I may be craving that, but I’m going to abstain,'” said Brown. “Exercise could not only be beneficial physically for weight loss but also mentally to gain control over cravings for unhealthy foods.”

The researchers trained 28 rats to press a lever that turned on a light and made a tone before dispensing a high-fat pellet. After the training period, they tested to see how many times the rats would press the lever just to get the light and tone cue.

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

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

Though this is a novel study, Brown said it builds on earlier work that first defined the term “incubation of craving“. Brown also gave credit to research showing that exercise can blunt cravings for cocaine.

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

Being able to disregard these signals could be yet another way exercise enhances health, Brown said.

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

Source: Washington State University

Exercise Protects Ageing Synapses

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When elderly people stay active, their brains have more proteins that enhance the connections between neurons to maintain healthy cognition, according to a study published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

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

“Our work is the first that uses human data to show that synaptic protein regulation is related to physical activity and may drive the beneficial cognitive outcomes we see,” said lead author Kaitlin Casaletto, PhD.

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

Dr Casaletto collaborated with William Honer, MD, a professor of psychiatry at the University of British Columbia and senior author of the study, to leverage data from the Memory and Aging Project at Rush University in Chicago. The project tracked the late-life physical activity of elderly participants, who also agreed to donate their brains upon death.

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

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

Surprisingly, the effects ranged beyond the hippocampus to include other brain regions associated with cognitive function.

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

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

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

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

Source: University of California in San Francisco

A ‘Sweet Spot’ for Exercise to Reverse Cognitive Decline

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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.

Source: University of Queensland

Just Ten Minutes of Running Boosts Cognitive Function

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Researchers have found that a mere ten minutes of running at moderate intensity boosts blood flow to the bilateral 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.

Source: EurekAlert!

Exercise Really is a Natural High

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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

Source: University of Nottingham

No Risk of Developing Knee Osteoarthritis From Exercise

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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.

Source: Wiley

‘Uncomfortable’ Urban Spaces Result in Slower, Uncertain Walking

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.

Source: University of Bristol

Physical Activity, Less Sitting Reduces Risk of Sleep Apnoea

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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.

Source: European Lung Foundation