Category: Exercise

Categories : Cardiovascular Disease ExerciseTags :

The Effect of Physical Fitness on Mortality is Overestimated

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Many observational studies have shown that people who exercise more and have good cardiorespiratory fitness early in life are at lower risk of premature death from causes such as cancer and cardiovascular disease. But a new study published in the European Journal of Preventive Cardiology suggests that the association between physical fitness and a reduced risk of mortality may be misleading.

“We found that people with high fitness levels in late adolescence had a lower risk of dying prematurely, for example from cardiovascular disease, compared to those with low fitness levels. But when we looked at their risk of dying in random accidents, we found an almost similarly strong association. This suggests that people with high and low fitness levels may differ in other important ways, which is something that previous studies have not fully taken into account,” says Marcel Ballin, associated researcher in epidemiology and lead author of the study.

Conscription data from over 1 million men

In the study, the researchers leveraged data from 1.1 million Swedish men who were conscripted for military service between the years 1972 and 1995. The men, who were on average 18 years old at the time of conscription, were divided into five groups based on their fitness level at the time. They were then followed until their 60s or until they died. With access to the National Cause of Death Register, the researchers were able to see their cause of death. They subsequently used different methods to study the association between fitness level in late adolescence and premature death.

The researchers started with a traditional analysis of mortality from cardiovascular disease, cancer and from all causes, as in previous observational studies. They adjusted their statistical models for factors such as BMI, age at conscription, year of conscription, and parents’ income and education level. The results showed that the group with the highest fitness level had a 58% lower risk of dying from cardiovascular disease, a 31% lower risk of dying from cancer, and a 53% lower risk of dying from all causes, compared with the group with the lowest fitness level.

Very similar risk of dying in random accidents

Next, the researchers examined how fitness was associated with the risk of dying in random accidents such as car accidents, drownings and homicides. They chose random accidents because they assumed that there ought to be no association between the men’s fitness in late adolescence and the risk of dying in random accidents. This method is called negative control outcome analysis and involves testing the validity of your results for a primary outcome by comparing them with an outcome where no association ought to be found. If, however, an association is found, it may indicate that the groups studied are not actually comparable, and that the study suffers from what is typically referred to as confounding. The researchers found that men with the highest fitness levels had a 53% lower risk of dying in random accidents. Yet, it is unlikely that the men’s fitness would have such a big effect on their risk of dying in random accidents.

These results were also confirmed when the researchers used the sibling comparison design. Using this method, the researchers compared the risk of premature death between siblings with different fitness levels to control for all the factors that the siblings share such as behaviours, environmental factors, and some genetic factors.

“It surprised us that the association with accidental mortality reflected the other associations, even after we controlled for all the factors that siblings share. This underlines how strong the assumptions are that you make in observational studies, since it appears to be very difficult to create comparable groups. The consequences may be that you overestimate the magnitudes of the effects you find,” says Marcel Ballin.

Picture confirmed in other studies

The study is one of the largest of its kind in which researchers used negative control outcomes to investigate whether the associations between fitness and mortality are in fact valid. The results in this study are also supported by other research.

“That the effects of good cardiorespiratory fitness may be overstated might sound controversial to some, but the fact is that if you look at the results from studies others than traditional observational studies, a more nuanced picture does emerge. A number of twin studies for example have found similar results. Some genetic studies also suggest that there are genes that affect both the propensity to be physically active or have a good fitness level, and the risk of developing diseases such as cardiovascular disease.”

Important to base interventions on correct estimates

Marcel Ballin also argues that there are many different reasons for promoting physical activity. However, large-scale interventions or policy changes intended to apply to the entire population must be based on reliable estimates – otherwise there is a risk of expecting effects that have in fact been overestimated.

“Our results should not be interpreted as if physical activity and exercise are ineffective or that you should not try to promote it. But to create a more nuanced understanding of how big the effects of fitness actually are on different outcomes, we need to use several different methods. If we just ask the question in the same way, we will always get the same answer. It’s only when we get the same answer to a question that we have asked in slightly different ways that we can be sure that the findings are accurate,” says Marcel Ballin.

Source: Uppsala University

Categories : ExerciseTags :

Research Finds New Explanation for Muscle Memory in Muscle Proteins

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Memory traces from resistance training persist for over two months

Photo by John Arano on Unsplash

Researchers have found a possible new explanation for muscle memory by investigating thousands of muscle proteins. This study by the Faculty of Sport and Health Sciences at the University of Jyväskylä showed for the first time that muscles “remember” training at the protein level. The memory trace of previous resistance training persists in muscle proteins for over two months.

It is often thought that the effects of exercise are short-lived, and a break from the gym for just a few weeks can cause stress over muscle loss for some people. However, the research from the University of Jyväskylä has shown that this stress is partly unnecessary, as the effects of resistance training persist in muscles for up to two months and the gains are fast when training is started again after the break. But what mechanisms and changes at the cellular and molecular levels explain muscle memory? This is what the researchers investigated by studying the quantities of thousands of muscle proteins from muscle.

In the study, ten weeks of resistance training was followed by a break of the same length and then followed by another ten weeks of resistance training. Using the proteomics method, it was possible to simultaneously study the quantities of over 3,000 muscle proteins using advanced mass spectrometry equipment.

Training gets encoded into muscle proteins

The study found two types of change profiles in muscle proteins.

Some proteins changed as a result of training, returned to their pre-training state during the break, and changed again during the new training period similarly to the first training period. These included proteins related to aerobic metabolism.

Another group of proteins changed as a result of training and remained changed during the break and after the new training period. Among these proteins were several calcium-binding proteins, such as calpain-2, whose gene has recently been identified to retain a memory trace even after a training break.

“At the level of the number of muscle nuclei and the memory traces of genes, that is, epigenetics, long-term responses that persist even after a break and possibly explain ‘muscle memory’ have previously been observed,” says the lead researcher, Professor Juha Hulmi from the Faculty of Sport and Health Sciences. 

“Now, for the first time, we have shown that muscles ‘remember’ previous resistance training at the protein level for at least two and a half months.”

“So, even though muscles eventually shrink back to their original size during a long training break, a memory trace of previous training remains in the muscles. This can make it easier to start training again”, explains Hulmi.

The  data collection was carried out at the Faculty of Sport and Health Sciences, University of Jyväskylä. The participants were young adult and middle-aged Finnish men and women who were physically quite active but had no previous experience of systematic resistance training. Proteomic analyses were conducted on 116 muscle samples at the University of Helsinki in the laboratory of research director Markku Varjosalo.   

Source: University of Jyväskylä

Categories : ExerciseTags :

Are High Support Bras Bad for the Back?

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Research from the University of Portsmouth suggests that bras offering excessive bounce reduction may come with hidden consequences for spinal health.

Sports bras are extremely popular in the health and fitness world, with the bra industry often emphasising “bounce reduction” as a key indicator of a bra’s performance. However, a new study suggests that high-support bras that significantly reduce breast bounce could have a detrimental effect on the spine.

Published in the European Journal of Sport Science, the preliminary research revealed that bras designed to prevent breast bounce during exercise may unknowingly cause potential unseen consequences on the musculoskeletal system.

Dr Chris Mills and a team from the School of Psychology, Sport and Health Sciences at the University of Portsmouth employed advanced tools – including motion capture, force platforms, and a 3D surface scanner – to investigate the effects of breast movement on spinal rotational forces. Using a first-of-its-kind whole-body, female-specific musculoskeletal model, the study examined how varying levels of breast support influenced torso motion, breast forces, and spinal moments during running.

The findings revealed that while sports bras are essential for reducing breast pain during exercise, achieving 100 percent bounce reduction could unintentionally increase loading on the spine. 

Simulated conditions showed that bras eliminating breast movement led to higher spinal moments, which could elevate the risk of lumbar back pain. Researchers emphasised the importance of striking an optimal balance in bra design; reducing breast bounce without overloading the spine.

r Mills said: “While a supportive sports bra is crucial for exercise comfort, excessive bounce reduction may place additional strain on spinal muscles, increasing the risk of back pain.”

The study, built on two decades of research by the University’s Research Group in Breast Health, highlights the need for bra manufacturers to consider the unseen musculoskeletal impacts on the human body in their designs. Professor Wakefield-Scurr, often referred to as the ‘Bra Professor’, added, “These findings suggest that striving for maximum bounce reduction may inadvertently pose challenges to spinal health during activities like running.

“As sports bras evolve, this study challenges industry leaders to innovate designs that balance comfort, breast support, and holistic health, ensuring that bounce reduction doesn’t come at a cost to spinal health.”

The creation of a subject-specific female musculoskeletal model enabled researchers to gain a detailed understanding and approximation of changes in spinal moments, following simulated changes in breast motion during running.

Previous research by the Portsmouth team used the model to predict changes in spinal moments after breast surgery. 

“The musculoskeletal model could become a useful tool in predicting appropriate and personalised rehabilitation recommendations, which could help ease the loading on the spine after breast surgeries”, explained Dr Mills.

“Understanding the individual muscular contributions will help to develop personalised pre-surgical rehabilitation programs as well as bras that work in tandem with each female body to maximise performance and reduce injury risk.

“Moving forward the key goal is to determine what is the optimal amount of bounce reduction to both reduce exercise induced breast pain and also the internal loading on the spine during physical activity.”

Source: University of Portsmouth

Categories : Exercise NeurologyTags :

Myelin Becomes a Nutrient of Last Resort for the Brain

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Myelin sheath damage. Credit: Scientific Animations CC4.0

According to a study published by Nature Metabolism, marathon runners experience reversible changes in their brain myelin. These findings indicate that myelin exhibits previously unknown behaviour, which contributes towards the brain’s energy metabolism when other sources of energy are running low. Understanding how myelin in the runners recovers quickly may provide clues for developing treatments for demyelinating diseases such as multiple sclerosis.

Exercise for a long period of time forces the human body to resort to its energy reserves. When running a marathon, for example, the body mainly consumes carbohydrates, such as glycogen, as a source of energy, but it resorts to fats when the glycogen in the muscles is used up. Myelin, which surrounds neurons in the brain and acts as an electrical insulator, mainly comprises lipids, and previous research in rodents suggests that these lipids can act as an energy reserve in extreme metabolic conditions.

A study conducted by researchers from the UPV/EHU, CIC biomaGUNE and IIS Biobizkaia shows that people who run a marathon experience a decrease in the amount of myelin in certain regions of the brain. According to the study, this effect is completely reversed two months after the marathon.

Carlos Matute, Professor of Anatomy and Human Embriology at the UPV/EHU and a researcher at IIS Biobizkaia, and Pedro Ramos-Cabrer, Ikerbasque Research Professor at CIC biomaGUNE, together with Alberto Cabrera-Zubizarreta, radiologist at HT Médica, used magnetic resonance imaging to obtain images of the brains of ten marathon runners (eight men and two women) before and 48 hours after the 42-kilometre race. Likewise, the researchers took images of the brains of two of the runners two weeks after the race, and of six runners two months after the race as a follow-up.

By measuring the fraction of myelin water in the brain – an indirect indicator of the amount of myelin – the authors discovered “a reduction in the myelin content in 12 areas of white matter in the brain, which are related to motor coordination and sensory and emotional integration”, explained Carlos Matute. Two weeks later, “the myelin concentrations had increased substantially, but had not yet reached pre-race levels”, added Pedro Ramos. The authors saw that the myelin content had recovered fully two months after the marathon.

Myelin, the brain’s fuel

The researchers concluded that “myelin seems to act as an energy source when other brain nutrients are depleted during endurance exercise, and that further research is needed to establish how extreme exercise is related to the amount of myelin in the brain. Trials in a larger cohort are needed”, said Ramos-Cabrer.

This study reveals that “brain energy metabolism is more complex than previously thought. The use of myelin as brain fuel opens up new insights into the brain’s energy requirements”, explained Matute. Furthermore, according to the authors, more studies are needed to assess whether these changes exert any effect on the neurophysiological and cognitive functions associated with these regions, but they point out that most of the myelin in the brain is not affected.

The results of this work break new ground in the energy role of healthy, aging and diseased myelin in the brain. “Understanding how the myelin in the runners recovers quickly may provide clues for developing treatments for demyelinating diseases, such as multiple sclerosis, in which the disappearance of myelin and, therefore, of its energy contribution, facilitates structural damage and degeneration,” said Matute. At the same time, the researchers are keen to stress that running marathons is not harmful for the brain; “on the contrary, the use and replacement of myelin as an energy reserve is beneficial because this exercises the brain’s metabolic machinery”.

Source: University of the Basque Country

Categories : ExerciseTags :

Any Form of Exercise can Significantly Boost Brain Function

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Research findings are good news for couch potatoes

Photo by RDNE Stock project

Whether it’s an early morning jog, or a touch of Tai Chi, groundbreaking research from the University of South Australia shows that any form of exercise can significantly boost brain function and memory across children, adults, and older adults.

In the largest, most comprehensive umbrella review to date, researchers found that regular exercise improves general cognition, memory, and executive function in both healthy individuals and those with clinical conditions, reinforcing exercise as an essential, inclusive activity for optimising cognitive health. The review appears in the British Journal of Sports Medicine.

Synthesising findings from 133 systematic reviews, covering 2724 randomised controlled trials and 258 279 participants, the systematic umbrella and meta-meta-analysis found that:

  • low- to moderate-intensity exercise had the greatest benefits for brain function and memory
  • children and adolescents showed the greatest improvements in memory, while people with ADHD saw the biggest gains in executive function
  • yoga, Tai Chi, and exergames (active video games) delivered the most significant cognitive benefits.

Lead researcher, UniSA’s Dr Ben Singh, says the findings provide a comprehensive understanding of how different types, intensities, and durations of exercise influence cognitive function.

“Exercise has a profound effect on physical health, but we also know it benefits brain function. What this study confirms is that even low-intensity exercise – like yoga or walking – can improve cognition, making it accessible to people of all ages and abilities,” Dr Singh says.

“In particular, we found that benefits were delivered quickly – with clear gains within 1-3 months, highlighting that even small bursts of activity can make a big difference. It also signals that trying out new activities could play a key role in keeping the brain engaged and active.

“For children and teens, exercise was especially beneficial for developing memory, while for people with ADHD, it helped improve focus, reduce impulsivity, and enhance executive function.

“We also found that mind-body exercises, like Tai Chi and yoga, had the most significant impact on memory, while exergames – such as Pokémon Go – were highly effective for general cognition. This is an encouraging finding, as it suggests that engaging, low-impact activities can offer real cognitive benefits.”

Senior researcher, Professor Carol Maher says exercise should be encouraged as a cognitive health strategy across all ages and fitness levels.

“Cognitive decline and neurodegenerative diseases are growing global health concerns, underscoring the urgent need to identify effective strategies to preserve and enhance cognitive function across the lifespan,” Prof Maher says.

“This study presents compelling evidence that exercise should be integrated into healthcare and education settings to promote cognitive well-being.

“Knowing that even small amounts of exercise can improve memory and brain function – especially for those at higher risk – presents a clear opportunity for exercise to be included in clinical and public health guidelines.”

Source: University of South Australia

Categories : Cardiovascular Disease ExerciseTags :

Preventable Cardiac Deaths during Marathons are Down

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While more people than ever are running marathons in the U.S., the risk of dying from a heart attack during a run has fallen dramatically in recent years. That’s a key conclusion from a new study by Jonathan Kim, associate professor in the Emory School of Medicine. Kim’s research is a follow-up to a study he published in 2012 — the first investigation into unexpected cardiac arrests during long distance running events.

The new findings, published in JAMA, indicate that, while the rate of marathon runners who suffer cardiac arrests remained unchanged, their chance for survival is twice what it was in the past. Far fewer marathon runners who suffer cardiac arrest are now dying of it.

“We continue to see media reports about unfortunate cases of cardiac arrest during long distance running events,” Kim says. “But, has the incidence of these events changed? Have there been changes in the most common causes of cardiac arrest? What are the factors associated with death and survival? It was a novel question to ask 13 years after our first analysis, and an important one because recreational running continues to increase in popularity.”

The challenge of finding data

More than 29 million people completed marathons in the U.S. between 2010 and 2023, triple the number of the previous decade, which Kim examined in his first study. There’s no central registry of race-related cardiac events, so for both studies, his team had to find their data through a range of sources, starting by contacting individual race directors.

“We leveraged a few sources including a comprehensive review of media reports,” Kim says. “We also had contact information for all race directors and were able to reach approximately 70% of them who helped and told us the number of events during this specific timeline, including if the individual died and the sex of the participant.”

The researchers used extensive public internet searches to identify and reach out to runners who survived cardiac arrests or next-of-kin to construct detailed profiles of as many cases as possible. “The vast majority of cases were identifiable by public search engines. And all of the deaths were as well,” he says.

Analyzing this extensive database, Kim found that while the rate of cardiac arrests was about the same during the two periods — .60 per 100 000 participants now versus .54 per 100 000 participants in the earlier period — the rate of deaths from these cases, however, fell by half: from .39 per 100 000 to .19 per 100 000. That’s about a 50% decline in the death rate since 2000–2009. As before, cardiac arrests remained far more common among men than among women and more common in marathons than half marathons.

The sport’s growing awareness of cardiac death risk

What led to the dramatic change in death rates? Kim thinks the whole sport has become more aware of the risks and of the need to have emergency services available to runners, a conclusion he reached after interviewing as many survivors as he could find. “What we found was that every one of those people got hands-on cardiopulmonary resuscitation, but the vast majority also had immediate access to an automated external defibrillator. That’s the difference,” he says.

That survival rate is comparable to the cardiac arrest survival rate in other public places that now make defibrillators routinely available such as airport and casinos, which have seen similar declines in deaths.

Kim says his findings offer additional evidence of how important it is to make CPR training available to race participants and to strategically place defibrillators along the racecourse. It’s also important, he says, to better identify the most vulnerable in a population before they run a race.

“These are more often potentially preventable events,” he says. “Being able to identify people, more commonly older individuals with unrecognized cardiovascular risk factors, doesn’t mean they can’t run a race. Rather, it affords the opportunity to improve primary preventive cardiovascular care and potentially further reduce the risk of cardiac arrest during these events. The incidence of sudden cardiac arrest during long-distance races hasn’t changed in over twenty years. I think this is an important arena of future research.”

Source: Emory Health Sciences

Categories : Cancer ExerciseTags :

Can Exercise Help Reduce Survival Disparities in Colon Cancer Survivors?

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Study indicates that higher levels of physical activity may lessen and even eliminate survival disparities.

Photo by Barbara Olsen on Pexels

Physical activity may help colon cancer survivors achieve long-term survival rates similar to those of people in the general population, according to a recent study published by Wiley online in CANCER, a peer-reviewed journal of the American Cancer Society.

Individuals with colon cancer face higher rates of premature mortality than people in the general population with matched characteristics such as age and sex. To assess whether exercise might reduce this disparity, investigators analysed data from two posttreatment trials in patients with stage 3 colon cancer, with a total of 2875 patients who self-reported physical activity after cancer surgery and chemotherapy. The researchers also examined data on a matched general population from the National Center for Health Statistics. For all participants, physical activity was based on metabolic equivalent (MET) hours per week. (Health guidelines recommend 150 minutes of moderate-intensity exercise per week, translating to approximately 8 MET-hours/week.)

In the analysis of data from the first trial (called CALGB 89803), for patients who were alive at three years after cancer treatment, those with <3.0 MET-hours/week had subsequent 3-year overall survival rates that were 17.1% lower than the matched general population, but those with ≥18.0 MET-hours/week had only 3.5% lower subsequent 3-year overall survival rates than the matched general population. In the second trial (CALGB 80702), among patients who were alive at three years, those with <3.0 and ≥18.0 MET-hours/week had subsequent 3-year overall survival rates that were 10.8% and 4.4% lower than the matched general population, respectively.

In pooled analyses of the two trials, among the 1908 patients who were alive and did not have cancer recurrence by year three, those with <3.0 and ≥18.0 MET-hours/week had subsequent 3-year overall survival rates that were 3.1% lower and 2.9% higher than the matched general population, respectively. Therefore, cancer survivors who were tumour-free by year three and regularly exercised achieved even better subsequent survival rates than those seen in the matched general population.

“This new information can help patients with colon cancer understand how factors that they can control—their physical activity levels—can have a meaningful impact on their long-term prognosis,” said lead author Justin C. Brown, PhD, of the Pennington Biomedical Research Center and the Louisiana State University Health Sciences Center. “Also, medical and public health personnel and policymakers are always seeking new ways to communicate the benefits of a healthy lifestyle. Quantifying how physical activity may enable a patient with colon cancer to have a survival experience that approximates their friends and family without cancer could be a simple but powerful piece of information that can be leveraged to help everyone understand the health benefits of physical activity.”

Source: Wiley

Categories : Ageing ExerciseTags :

Twin Study Offers New Insights into Whether Exercise Extends life

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In a decades-long study following twins, researchers from the University of Jyväskylä, Finland, investigated the links between long-term leisure-time physical activity and mortality. They also sought to determine whether physical activity can mitigate the increased risk of mortality due to genetic predisposition to diseases. Moreover, they examined the relationship between physical activity and later biological aging. 

The study included 22 750 Finnish twins born before 1958 whose leisure-time physical activity was assessed in 1975, 1981 and 1990. Mortality follow-up continued until the end of 2020.

Moderate activity yields maximum longevity benefits

Four distinct sub-groups were identified from the data, which was based on leisure-time physical activity over the 15-year follow-up: sedentary, moderately active, active and highly active groups. When the differences in mortality between the groups were examined at the 30-year follow-up, it was found that the greatest benefit – a 7% lower risk of mortality – was achieved between the sedentary and moderately active groups. A higher level of physical activity brought no additional benefit. 

When mortality was examined separately in the short and long term, a clear association was found in the short-term: the higher the level of physical activity, the lower the mortality risk. In the long term, however, those who were highly active did not differ from those who were sedentary in terms of mortality.

“An underlying pre-disease state can limit physical activity and ultimately lead to death, not the lack of exercise itself.”

“This can bias the association between physical activity and mortality in the short term”,  says Associate Professor Elina Sillanpää from the Faculty of Sports and Health Sciences. 

Meeting physical activity guidelines does not guarantee a lower mortality risk

The researchers also investigated whether following the World Health Organization’s physical activity guidelines affects mortality and genetic disease risk. The guidelines suggest 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous activity weekly. The study found that meeting these guidelines did not lower mortality risk or alter genetic disease risk. Even for twins who met the recommended levels of PA over a 15-year period, no statistically significant difference in mortality rates was found compared to their less active twin pair.

“The widely observed favorable association between physical activity and mortality are based on observational studies that are prone to bias from different sources.” 

“In our studies, we aimed to account for various sources of biases, and combined with the long follow-up period, we could not confirm that adhering to physical activity guidelines mitigates genetic cardiovascular disease risk or causally reduces mortality”, says postdoctoral researcher Laura Joensuu from the Faculty of Sports and Health Sciences.  

Link between physical activity and biological aging is U-shaped

For the subsample of twins, biological aging was determined from blood samples using epigenetic clocks. Epigenetic clocks allow a person’s biological aging rate to be estimated based on methyl groups that regulate gene expression and are linked to aging process. 

“We found that the association between leisure-time physical activity and biological aging was U-shaped: Biological aging was accelerated in those who exercised the least and the most,” says Sillanpää.

Other lifestyles, such as smoking and alcohol consumption, largely explained the favourable associations of physical activity with biological aging. 

Genetic data were available for 4897 twins. The genetic susceptibility of twins to coronary artery disease, as well as systolic and diastolic blood pressure was assessed using new polygenic risk scores, which sum the genome-wide susceptibility to morbidity. In addition, all-cause and cardiovascular mortality was followed in 180 identical twin pairs. The biological aging rate of 1153 twins was assessed from a blood sample.

Source: University of Jyväskylä

Categories : Ageing ExerciseTags :

Brown Fat Could Help Maintain Exercise Capacity in Aging

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Rutgers Health researchers have made discoveries about brown fat that may open a new path to helping people stay physically fit as they age. A team from Rutgers New Jersey Medical School found that mice lacking a specific gene developed an unusually potent form of brown fat tissue that expanded lifespan and increased exercise capacity by roughly 30%. The team is working on a drug that could mimic these effects in humans.

“Exercise capacity diminishes as you get older, and to have a technique that could enhance exercise performance would be very beneficial for healthful aging,” said Stephen Vatner, university professor and director of the Cardiovascular Research Institute in the medical school’s Department of Cell Biology and Molecular Medicine and senior author of the study in Aging Cell. “This mouse model performs exercise better than their normal littermates.”

Unlike white fat, which stores energy, brown fat burns calories and helps regulate body temperature. This study revealed brown fat also plays a crucial role in exercise capacity by improving blood flow to muscles during physical activity.

The genetically modified mice produced unusually high amounts of active brown fat and showed about 30% better exercise performance than normal mice, both in speed and time to exhaustion.

The discovery emerged from broader research into healthy aging. The modified mice, which lack a protein called RGS14, live about 20% longer than normal mice, with females living longer than males – similar to the pattern seen in humans. Even at advanced ages, they maintain a healthier appearance, avoiding the typical signs of aging, such as loss of hair and graying that appear in normal elderly mice. Their brown adipose tissue also protects them from obesity, glucose intolerance, cardiovascular disorders, cancer and Alzheimer’s disease, in addition to reduced exercise tolerance.

To test whether the brown fat – rather than some other result from the missing genes –accounted for the benefits, the researchers transplanted the brown fat to normal mice. They noted that the recipients gained similar benefits within days. Transplants using regular brown fat from normal mice, by contrast, took eight weeks to produce much milder improvements.

The discovery could eventually improve human lifespans – the total time when people enjoy good mental and physical health.

“With all the medical advances, aging and longevity have increased in humans, but unfortunately, healthful aging hasn’t,” Vatner said. “There are a lot of diseases associated with aging – obesity, diabetes, myocardial ischemia, heart failure, cancer – and what we have to do is find new drugs based on models of healthful aging.”

Rather than develop a treatment that addresses aging broadly, which poses regulatory challenges, Vatner said his team plans to test for specific benefits such as improved exercise capacity and metabolism. This approach builds on their previous success in developing a drug based on a different mouse healthful longevity model.

“We’re working with some people to develop this agent, and hopefully, in another year or so, we’ll have a drug that we can test,” Vatner said.

In the meantime, techniques such as deliberate cold exposure can increase brown fat naturally. Studies have found such efforts to produce short-term benefits that range from enhanced immune system function to improved metabolic health, but Vatner said none of the studies have run long enough to find any effect on healthful aging.

He added that most people would prefer to increase brown fat levels by taking pills rather than ice baths and is optimistic about translating the newest finding into an effective medication.

Source: Rutgers University

Categories : Exercise Obstetrics & GynaecologyTags :

Researchers Debunk Common Beliefs About ‘Cycle Syncing’ and Muscles

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New research from McMaster kinesiologists is challenging the internet belief that timing resistance training to specific phases of the menstrual cycle boosts the body’s ability to build muscle and strength.

The researchers have shown that exercising at various points in the cycle had no impact — positive or negative — on the synthesis of new muscle proteins, a process essential to building and maintaining muscle.

The results, published in the print edition of the Journal of Physiology, debunk the popularly touted practice of cycle syncing, or tailoring workouts to align with the way hormones change throughout a woman’s menstrual cycle.

“Our findings conflict with the popular notion that there is some kind of hormonal advantage to performing different exercises in each phase,” explains Lauren Colenso-Semple, lead author of the study and a former graduate student in the Department of Kinesiology, who conducted the work while at McMaster.

“We saw no differences, regardless of cycle timing.”

For the study, researchers monitored the menstrual cycles of participants — all healthy young women — for three months to confirm their cycles were normal. Contrary to popular belief, only a small percentage of women — about 12 per cent — have a consistent 28-day cycle and ovulate regularly on Day 14 or the “textbook” menstrual cycle.

Participants then ingested a tracer molecule, a benign substance designed to track and monitor muscle protein levels. They performed heavy resistance exercise during two distinct phases of their menstrual cycles: the follicular phase, when estrogen levels are at their peak; and the luteal phase, characterized by peak progesterone levels.

Researchers observed no effect of either menstrual cycle phase on the production of muscle proteins.

Cycle syncing has been made popular by internet influencers to coordinate workouts, certain diets and lifestyle behaviours with the menstrual cycle.

There are fitness apps for tracking cycles, and social media channels are rife with advice and recommendations.

Proponents routinely cite a handful of scientific studies on animals as evidence that fluctuations in ovarian hormones can affect how human muscles respond to exercise, but this study shows that not to be correct.

“Our work shows that women who want to lift weights and recondition their muscles should feel free to do so in any phase of their cycle. There is no physiological difference in response to the exercise,” says Stuart Phillips, the Canada Research Chair in Skeletal Muscle Health at McMaster who supervised the study.

“It is important to tailor your training to how you feel.”

Scientists highlight the need for further research, particularly studies that focus on women’s health. This includes investigating how training, in relation to the menstrual cycle, affects women and how both oral and non-oral contraceptives influence their responses to exercise.

This article was first published on Brighter World. Read the original article.