Tag: exercise

Categories : ExerciseTags :

When Dieting, High-intensity Exercise Might Combat Cravings

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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

Categories : Diseases, Syndromes and ConditionsTags :

Cycling Can Improve Mobility in Myotonic Dystrophy

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Regular cycling can greatly improve mobility in patients with myotonic dystrophy (MD), an inherited genetic disease that causes muscle degeneration, according to research published in The Journal of Clinical Investigation. Professor Mark Tarnopolsky, senior author of the study, said that cycling for 35 minutes three times a week for 12 weeks led to a 32% increase in overall fitness in people with MD.

The participants also saw a 1.6-kilogram increase in their muscle mass and a two percent reduction of body fat. They were also able to walk an extra 47 metres in six minutes, when tested by researchers at the end of the 12-week trial.

The research team recruited 11 patients with MD to examine how effective cycling was in restoring and maintaining their physical health. Researchers also studied the underlying molecular mechanisms through which exercise strengthens the skeletal muscles, which can be severely weakened by MD.

“Exercise really is medicine – we just need to get the message out,” said Prof Tarnopolsky. “Myotonic dystrophy is a progressive condition that will impair your mobility and can put you in a wheelchair. There is no cure for it and only regular exercise helps you achieve better function.”

Prof Tarnopolsky said that some patients with MD are even advised by their doctors not to exercise, for fear of making their condition worse, but that is now proven false. 

Prior studies with mouse models showed a range of similar physiological benefits from regular exercise, the researchers said. MD is the most commonly diagnosed type of muscular dystrophy in adults, and the second most prevalent of all muscular dystrophies, noted Prof Tarnopolsky.

MD’s main symptoms include severe skeletal muscle atrophy, general muscle weakness, reduced lung capacity and impaired heart function. Other symptoms may include cataracts, endocrine disorders including diabetes and gastro-intestinal disorders. 

“MD itself is really a form of accelerated ageing,” said Prof Tarnopolsky.

Source: McMaster University

Categories : CancerTags :

Exercise Slows Tumour Growth and Reduces Complications

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In mouse studies, researchers found that exercising prior to developing cancer was associated with slower tumour growth and helped reduce the effects of a cachexia, a cancer complication also known as wasting syndrome.

Cachexia is a metabolic wasting disorder that affects up to 80% of patients with advanced cancer and is associated with about a third of all deaths from cancer. Cachexia is characterised by severe progressive muscle wasting, a decline in heart structure and function and an overall poorer quality of life.

“Most exercise, especially aerobic exercise, is easily accessible and affordable,” said Louisa Tichy, a graduate student in Traci Parry’s lab at the University of North Carolina at Greensboro. “Therefore, engaging in consistent aerobic exercise such as running is a cost-effective way to reduce the risk of cancer and cancer complications.”

Tichy presented the research at the American Society for Investigative Pathology annual meeting.

Previous research has shown that exercise could have anti-inflammatory effects and might positively impact cancer cachexia by slowing its development and preserving cardiac structure and function. However, very few studies have focused on preconditioning.

“Our preclinical study indicated that preconditioning – or exercise prior to tumour bearing – appears to play an important cardioprotective role during cancer cachexia by preserving cardiac structure and function,” said Tichy. “It also helped stunt tumour growth, even when animals did not exercise during the tumour-bearing period.”

For the new study, the researchers studied mice that exercised on a treadmill for eight weeks and non-exercising mice. After the eight weeks, the researchers induced cancer in some of the exercised mice and some sedentary mice while keeping some mice from both groups cancer-free to act as controls.

Mice with cancer and a sedentary lifestyle were found to have poorer heart function – as measured with echocardiography – than the mice that exercised prior to cancer induction. Also, exercising mice had a smaller tumour volume and a 60% smaller tumour mass than the sedentary mice.

“This data is crucial in identifying the significance of exercise and the best timing of exercise as a protective and preventative measure against the detrimental effects of cancer cachexia,” said Tichy.

Understanding how the underlying proteins and pathways are affected by cancer and exercise can be used to inform exercise interventions. The researchers say that devising safe and effective exercise interventions for cancer patients would require evaluating the best intensity, duration and timing of exercise in preclinical models before human tests.

Source: EurekAlert!

Categories : VaccinesTags :

Exercise After Vaccination Boosts Antibodies

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Researchers have found that a 90 minute bout of mild- to moderate-intensity exercise directly after a receiving a flu or COVID vaccine may provide an extra immune boost.

In the paper, published in Brain, Behavior, and Immunity, participants who cycled on a stationary bike or took a brisk walk for an hour-and-a-half after receiving a vaccine injection produced more antibodies in the following four weeks compared to participants who sat or continued with their daily routine post-immunisation. When the researchers ran the experiment with mice and treadmills, similar results were observed.

“Our preliminary results are the first to demonstrate a specific amount of time can enhance the body’s antibody response to the Pfizer-BioNtech COVID vaccine and two vaccines for influenza,” said Kinesiology Professor Marian Kohut, lead author of the study.

The vaccine recipients would be able to benefit people who could not cope with such exercise. Nearly half of the participants in the experiment had a BMI in the overweight or obese category. During 90 minutes of exercise, they focused on maintaining a pace that kept their heart rate around 120–140 beats per minute rather than distance.

However, the exercise duration appeared to be important: the researchers also ran the experiment with just 45-minutes of exercising. The shorter workout did not increase the participants’ antibody levels. Prof Kohut said a follow-up study might test whether 60 minutes is sufficient.

As to why prolonged, mild- to moderate-intensity exercise could improve the body’s immune response, Prof Kohut said there may be multiple reasons. Exercise increases blood and lymph flow, which helps circulate immune cells. As these cells move around the body, they’re more likely to detect antigens. The mouse experiment data also suggested that interferon alpha produced during exercise helps generate virus-specific antibodies and T- cells.

“A lot more research is needed to answer the why and how,” said Prof Kohut. “There are so many changes that take place when we exercise – metabolic, biochemical, neuroendocrine, circulatory. So, there’s probably a combination of factors that contribute to the antibody response we found in our study.”

The researchers are continuing to track the antibody response in the participants six months post-immunisation and have launched another study that focuses on exercise’s effects on people who receive booster shots.

Source: Iowa State University

Categories : Ageing Cardiovascular DiseaseTags :

Reduced Heart Failure Risk in Postmenopausal Women Who Walk Faster

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A study of postmenopausal women, published in the Journal of the American Geriatrics Society, found that those who reported a faster walking pace had a lower risk of developing heart failure. 

Among 25 183 women aged 50 to 79 years, there were 1455 cases of hospitalisation for heart failure during a median follow-up of 16.9 years. Compared with women who walked at a casual pace, those who walked at an average pace or fast pace had 27% and 34% lower risks of heart failure, respectively.

Fast walking for less than 1 hour per week was associated with the same risk reduction of heart failure as average or casual walking for more than 2 hours per week.

“This study confirms other studies demonstrating the importance of walking speed on mortality and other cardiovascular outcomes,” said senior author Charles B. Eaton, MD, MS, of the Warren Alpert Medical School of Brown University. “Given that limited time for exercise is frequently given as a barrier to regular physical activity, walking faster but for less time might provide similar health benefits as the recommended 150 minutes per week of moderate physical activity.”

Further study is warranted to determine whether interventions to increase the walking pace in older adults will reduce heart failure risk and whether fast pace will compensate for the short duration of walking.

Source: Wiley

Categories : AgeingTags :

Muscles may Stay Younger at an Epigenetic Level through Exercise

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While the benefits of exercise in ageing have been well established, such as lowering risk of cardiovascular disease, a new study that used mice demonstrated that exercise in aged individuals could help muscles stay younger at an epigenetic level.

Despite generating a wealth of data, the study, which was published in Aging Cell, made use of a relatively straightforward experiment. Lab mice nearing the end of their natural lifespan, at 22 months, were allowed access to a weighted exercise wheel. Mice generally run voluntarily, without any coercion. Older mice will run anywhere from six to eight kilometres a day, mostly in spurts, while younger mice may run up to 10 to 12 kilometres. The weighted wheel ensured they built muscle. While there isn’t a direct analogue to most human exercise routines, first author Kevin Murach, assistant professor at the University of Arkansas, likened it to “a soldier carrying a heavy backpack many miles.”

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

The science behind this hinges largely on DNA methylation, where methyl groups attach to DNA, altering their function. As the body ages, there tends to be increased DNA methylation, or even hypermethylation, at promoter sites on genes in muscle. “DNA methylation changes in a lifespan tend to happen in a somewhat systematic fashion,” Murach explained, “to the point you can look at someone’s DNA from a given tissue sample and with a fair degree of accuracy predict their chronological age.” Due to this, researchers can use one of a number of “methylation clocks” to determine the age of a DNA sample.

While the paper strengthens the case for exercise, much work remains to be done. Though there is a clear connection between methylation and ageing, the relationship between methylation and muscle function is less clear. Murach is not yet prepared to say that the reversal of methylation with exercise causes improved muscle health. “That’s not what the study was set up to do,” he explained. However, he intends to pursue future studies to determine if “changes in methylation result in altered muscle function.”

Source: University of Arkansas

Categories : Ageing Neurodegenerative DiseasesTags :

How Many Intervention Sessions to Prevent Cognitive Decline?

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Physical activity, diet and cognitive stimulation are all known to be good interventions for the prevention of Alzheimer’s disease and dementia. Now an international team of researchers has determined that only about a dozen intervention sessions are all that were needed to observe an improvement in cognition.

Until now, the number of sessions or “doses” needed for optimal effect has been unknown. Published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, the study led by Université de Montréal psychology professor Sylvie Belleville showed that between 12 and 14 sessions were all that were needed to boost cognitive ability, though the gain observed levelled off with more sessions.

“In pharmacological studies, every effort is made to define an optimal treatment dose needed to observe the expected effects, “ said Prof Belleville,  a neuropsychologist and researcher at the research centre of the UdeM-affiliated Institut universitaire de gériatrie de Montréal. “This is rarely done in non-pharmacological studies, especially those on the prevention of cognitive decline, where little information is available to identify this dose.

“Defining an optimal number of treatment sessions is therefore crucial.,” she continued. “Indeed, proposing too few sessions will produce no noticeable improvement effects, but too many sessions is also undesirable as these interventions are costly. They are costly both for the individual who follows the treatments, in terms of time and involvement, and for the organisation offering these treatments.”

The study is based on a secondary analysis of data from the three-year Multidomain Alzheimer Preventive Trial (MAPT) and examined 749 participants who received a range of interventions aimed at preventing cognitive decline. These interventions included dietary advice, physical activity and cognitive stimulation.

In their research, Prof Belleville’s team noted that people’s individuality should be considered when determining the optimal treatment dose.

In their study, the researchers gauged the effects of the sessions in terms of each participant’s age, gender, education level, and cognitive and physical condition. The relationship between the “dose” each received and their cognitive improvement was then analysed.

The findings revealed an increase with dose followed by a plateau effect after 12 to 14 sessions. However, participants with lower levels of education or more risk factors for frailty did benefit from more sessions.

The researchers concluded that it’s important to pinpoint an optimal dose and to customise the treatment for each individual. Not only is “dosage” an important component of behavioural interventions, it can also provide valuable information in resource-constrained settings, helping public-health agencies develop effective prevention programs and offer guidance to older adults and clinicians.

Source: University of Montreal

Categories : AgeingTags :

Grip Strength is an Important Health Marker in Older Women

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Source: CDC

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. 

Source: Wiley

Categories : Ageing ExerciseTags :

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

Categories : ExerciseTags :

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!