Category: Exercise

Firefighter Study Reveals how Extreme Exercise can Suppress the Immune System

Source: CC0

A study of firefighters on a punishing training course has revealed clues as to why extreme exercise temporarily weakens the immune system – a phenomenon seen in elite athletes. The findings, published in Military Medical Research, may lead to better ways to support the health of people who undergo extreme exertion, such as firefighters tackling wildfires.

Thirteen firefighters volunteered for the study, average age 25 and male. They went through a rigorous training exercise, carrying 9 to 20kg of gear over hilly terrain during a 45-minute training exercise in the California sun. Gloves, helmets, flashlights, goggles, and more weighted them down as they sprinted through the countryside wearing fire-resistant clothing to show they were ready to serve as wildland firefighters.

After the training, they immediately gave samples of their blood, saliva, and urine for analysis. Two were excluded, one being unable to finish the course and the other arriving to late to provide a sample. The 11 participants who completed the course lost an average of 2.2% of their initial weight.

Then, the scientists from the Department of Energy’s Pacific Northwest National Laboratory (PNNL) analysed more than 4700 molecules, consisting of proteins, lipids, and metabolites, from each of the firefighters, looking to understand what happens when the body undergoes intense physical exercise. Measuring and interpreting the data from thousands of such measurements is a specialty of PNNL scientists who explore issues related to climate science and human health by analysing millions of sensitive measurements using mass spectrometry each year.

The researchers’ aim was to increase safety for first responders and others.

“Heat stress can be life threatening,” said Kristin Burnum-Johnson, a corresponding author of the study. “We wanted to take an in-depth look at what’s happening in the body and see if we’re able to detect danger from exhaustion in its earliest stages. Perhaps we can reduce the risk of strenuous exercise for first responders, athletes, and members of the military.”

As expected, the team detected hundreds of molecular changes in the firefighters. The differences before and after exercise underscored the body’s efforts at tissue damage and repair, maintenance of fluid balance, efforts to keep up with increased energy and oxygen demand, and the body’s attempts to repair and regenerate its proteins and other important substances.

But in the saliva, the team found some unexpected results. There was a change in the microbial mix of the mouth – the oral microbiome – showing that the body was increasingly on the lookout for bacterial invaders. Scientists also saw a decrease in signaling molecules important for inflammation and for fighting off viral infections.

A decrease in inflammation makes sense for people exercising vigorously; less inflammation allows people to breathe in air more quickly, meeting the body’s eager demand for more oxygen. Having fewer inflammatory signals in the respiratory system helps the body improve respiration and blood flow.

Less inflammation, more inhalation

But less inflammation leaves the body more vulnerable to viral respiratory infection, which other studies observed in elite athletes and others who exercise vigorously. Some studies have shown that a person is up to twice as likely to come down with a viral respiratory infection in the days after an especially energetic workout.

“People who are very fit might be more prone to viral respiratory infection immediately after vigorous exercise. Having less inflammatory activity to fight off an infection could be one cause,” said Ernesto Nakayasu, a corresponding author of the paper. He notes that the work provides a molecular basis for what clinicians have noticed in their patients who do strenuous workouts.

The team hopes that the findings will help explain why come people are more vulnerable to respiratory infection after a workout.

Source: DOE/Pacific Northwest National Laboratory

8000 Steps a Day is the Magic Number for Health Benefits

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An international study led by the University of Granada (UGR) has identified for the first time the optimal number of steps at which most people obtain the greatest benefits. The findings, published in the Journal of the American College of Cardiology, also show that walking pace provides additional benefits.

The idea that you should take 10 000 steps a day originated in Japan in the 1960s, but with no scientific basis – rather it is a popular number there. Researchers have now shown that, focusing on cardiovascular disease mortality, most of the benefits are seen at around 7000 steps.

The study provided the first scientific proof for how many steps you need to take per day to significantly reduce the risk of premature death: 8000. Given the average length of a human stride (76cm for men and 67cm for women), taking 8000 steps is equivalent to walking approximately 6.4km a day.

Researchers have also shown that the pace at which we walk has additional benefits, and that it is better to walk fast than slow. With regard to the risk of dying from cardiovascular disease, most of the benefits are seen at around 7000 steps.

The study identifies for the first time the optimal number of steps at which most people obtain the greatest benefits, and also shows that the pace at which you walk provides additional benefits.

The research was carried out in collaboration between researchers from the Netherlands (Radboud University Medical Center), Spain (Universities of Granada and Castilla-La Mancha) and the United States (Iowa State University).

“Traditionally, many people thought that you had to reach about 10 000 steps a day to obtain health benefits – an idea that came out of Japan in the 1960s but had no basis in science,” explains the lead author of the study, Francisco B. Ortega, a professor at the UGR’s Department of Physical Education and Sports.

Previously, no scientific basis

In Japan and China, the number 10 000 is a significant number, being the largest order of magnitude for common usage and also expressing the idea of ‘unending’. The Japanese cheer of banzai literally translates as ‘ten thousand years’.

For instance, the first pedometer marketed to the general public was the “10 000 steps meter” (a literal translation), but the figure had no scientific basis. “We’ve shown for the first time that the more steps you take, the better, and that there is no excessive number of steps that has been proven to be harmful to health,” says Ortega, who also points out that reaching 7000–9000 steps a day is a sensible health goal for most people.

The researchers conducted a systematic literature review and meta-analysis of data from twelve international studies involving more than 110 000 participants.

The results of this study are in line with other recent studies, which show that health benefits are obtained at less than 10 000 steps. “What makes our study different is that, for the first time, we set clear step targets,” explains Esmée Bakker, currently a Marie Curie Postdoctoral Research Fellow at the University of Granada and one of the lead authors of the study.

“In this study, we show that measurable benefits can be obtained with small increases in the number of steps per day, and that for people with low levels of physical activity, every additional 500 steps improves their health. This is good news because not everyone can walk almost 9000 steps a day, at least not at first, so you can set small, reachable goals and gradually make progress and increase the number of steps per day,” the researchers note.

The study revealed no difference between men and women. It also found that faster walking is associated with a reduced risk of mortality, regardless of the total number of steps per day. Additionally, according to Bakker, “it doesn’t matter how you count your steps, whether you wear a smartwatch, a wrist-based activity tracker or a smartphone in your pocket: the step targets are the same.”

Physical activity recommendations: steps

So, should we stop walking when we reach around nine thousand steps? “Absolutely not,” insists Francisco B. Ortega. “More steps are never bad. Our study showed that even as many as 16 000 steps a day does not pose a risk; on the contrary, there are additional benefits compared to walking 7000–9000 steps a day, but the differences in risk reduction are small. Furthermore, the step target should be age appropriate, with younger people being able to set a higher target than older people. It is also important to note that our study only looked at the effect on the risk of all-cause mortality and cardiovascular disease. There are other studies and a large body of scientific evidence that show that doing moderate and even vigorous physical activity is associated with many health benefits, including improvements in sleep quality and mental health, among many others.”

“Our study gives people clear and easily measurable goals,” Bakker continues. “The (inter)national physical activity recommendations advise adults to get 150–300 minutes of moderate-intensity exercise per week. But most people don’t know what exercises count as moderate intensity, making it difficult to verify their compliance with this exercise standard. Counting steps is much simpler, especially since most people have a smartphone or smartwatch these days. Herein lies the importance of our study: to provide simple and concrete targets for the number of daily steps that people can easily measure with their phones and smartwatches or wristbands, and thereby contribute to people’s health,” the authors conclude.

Source: University of Grenada

Science Finally Tackles the Question of How Warming up Improves Performance

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While top sports teams like the Springboks all know the importance of warming up their muscles before a game, it has not always been clear as to what is actually going on when muscles are warmed up, and whether all muscles are the same. Now, in a study recently published in the Journal of General Physiology, a Japanese research team has revealed how heating affects the contraction of different muscles, and how this might benefit populations in need of improved exercise performance as well as on the sports field.

Skeletal muscle contracts in response to electrical signals from the nervous system, which activate proteins in muscle cells, resulting in movement. The team previously explored how cardiac muscle contractions are affected by temperature, determining that the heart can contract efficiently within the body temperature range.

Next, using muscle proteins and advanced microscopy, the Osaka University-led team wanted to determine how temperature affects skeletal muscle: do skeletal muscles have similar temperature sensitivity, or are they different from cardiac muscle?

The research team found that some of the proteins in the muscle cells act as a temperature sensor, and that heating affects skeletal and cardiac contractile systems differently. “Our findings point to differences in the temperature sensitivity of proteins responsible for contraction in skeletal vs. cardiac muscles,” says co-lead author Kotaro Oyama. “Basically, the skeletal muscle that moves our body around is more sensitive to heating than the heart.”

The physiological significance of these findings will become clear when the functional difference between skeletal and cardiac muscle is considered. While skeletal muscle only generates a certain amount of force when required, the heart is meant to beat continuously.

“The higher temperature dependence of skeletal muscle may allow it to contract relatively quickly upon warming up, even from slight warming due to light movement or exercise. This means that the muscle can save energy and rest when not needed. In contrast, the lower temperature sensitivity of the heart may be beneficial for maintaining a continuous beat, regardless of temperature,” explains co-lead author Shuya Ishii.

This study provides new insights into how, at the protein level, warm-up before exercise enhances muscle performance. The discovery that some muscle proteins act as a temperature sensor may lead to a new hyperthermia strategy, in which skeletal muscle performance is improved by warming up the muscle. Incorporating appropriate warm-up routines into the daily lives of individuals, particularly the elderly population, could improve their muscle and exercise performance, thereby reducing the risk of injury and helping to maintain their independence.

Source: Osaka University

Strength Training may Reduce Health Risks of a High-protein Diet

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Progressive strength training using resistance can protect against the detrimental effects of a high-protein diet, according to new research in mice.

The study, published today as a Reviewed Preprint in eLife, presents what the editors describe as a valuable finding on the relationship between a high-protein diet and resistance exercise on fat accumulation and glucose homeostasis, supported by solid evidence. They say the findings will be relevant to dietitians and others trying to understand links between dietary protein, diabetes and exercise.

Dietary protein provides essential nutrients that control a wide variety of processes in the body and can influence health and lifespan. Protein consumption is generally thought of as good, promoting muscle growth and strength, especially when combined with exercise. Yet in people with a sedentary lifestyle, too much protein can increase the risk of heart disease, diabetes and death.

“We know that low-protein diets and diets with reduced levels of specific amino acids promote healthspan and lifespan in animals, and that the short-term restriction of protein improves the health of metabolically unhealthy, adult humans,” explains lead author Michaela Trautman, Research Assistant at the Department of Medicine, School of Medicine and Public Health, University of Wisconsin, US. “But this presents a paradox — if high dietary protein is so harmful, many people with high-protein diets or protein supplements would be overweight and at an increased risk of diabetes, whereas athletes with high-protein diets are among the most metabolically healthy.”

To examine the possibility that exercise can protect against the detrimental effects of a high-protein diet, the researchers used a progressive resistance-based strength training program in mice. The animals pulled a cart carrying an increasing load of weight down a track three times per week for a three-month period, or pulled an identical cart without any load for the same time period. One group of mice were fed a low-protein diet (7% of calories from protein) and a second group were fed a high-protein diet (36% of calories from protein). The team then compared the body composition, weight and metabolic measurements, such as blood glucose, of the different groups.

The results were as the team expected: the high-protein diet impaired metabolic health in sedentary mice pulling no weight; these mice gained excess fat mass compared to the low-protein diet mice. But in the mice pulling the increasing weight, a high-protein diet led to muscle growth especially in the forearm, and protected the animals from gaining fat. However, the exercise did not protect the mice from the effects of high protein on blood sugar control.

Additionally, although the high-protein-fed mice gained strength more quickly than the low-protein-fed mice, there was no difference in the maximum weight each set of mice could pull by the end of the study period, even though the mice fed high-protein diets were bigger and had larger muscles.

Although the evidence supporting the claims of the study was considered to be solid, the editors highlight a couple of limitations. For instance, the use of mice might limit the generalisability of the findings to humans, due to inherent physiological differences. The editors note that the findings would also be strengthened further by the inclusion of a direct investigation into the underlying molecular mechanisms responsible for the observed results.

“We know that many people deliberately consuming high-protein diets or consuming protein supplements to support their exercise regimen are not metabolically unhealthy, despite the body of evidence showing that high-protein levels can have detrimental metabolic effects,” says senior author Dudley Lamming, Associate Professor of Medicine (Endocrinology) at the Department of Medicine, School of Medicine and Public Health, University of Wisconsin. “Our research may explain this conundrum, by showing that resistance exercise protects from high-protein-induced fat gain in mice. This suggests that metabolically unhealthy, sedentary individuals with a high-protein diet or protein supplements might benefit from either reducing their protein intake or more resistance exercise.”

Source: eLife

Can Running Beat Antidepressants as a Treatment for Depression?

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The first study to compare effects of antidepressants with running exercises for anxiety, depression and overall health shows that they have about the same benefits for mental health, with health benefits for those assigned to running.

Professor Brenda Penninx from Vrije University, Amsterdam, presented the work at the ECNP conference in Barcelona (after recent publication in the Journal of Affective Disorders). Prof Penninx said, “We wanted to compare how exercise or antidepressants affect your general health, not just your mental health.”  

The 16-week course of running over the same period scores higher in terms of physical health improvement, whereas antidepressants lead to a slightly worse physical condition, as has been suggested by previous studies.  However, the drop-out rate was much higher in the group which initially chose exercise.

The researchers studied 141 patients with depression and/or anxiety. They were offered a choice of treatment; SSRI antidepressants for 16 weeks, or group-based running therapy for 16 weeks. 45 chose antidepressants, with 96 participating in running. The members of the group which chose antidepressants were slightly more depressed than the members of the group which chose to take running.

Professor Penninx said, “This study gave anxious and depressed people a real-life choice, medication or exercise. Interestingly, the majority opted for exercise, which led to the numbers in the running group being larger than in the medication group.”

Treatment with antidepressants required patients to adhere to their prescribed medication intake but this generally does not directly impact on daily behaviours. In contrast, exercise directly addresses the sedentary lifestyle often found in patients with depressive and anxiety disorders by encouraging persons to go outside, set personal goals, improve their fitness and participate in a group activity.  

The antidepressant group took the SSRI Escitalopram for 16 weeks. The running group aimed for two to three closely supervised 45-minute group sessions per week (over 16 weeks). The adherence to the protocol was lower in the running group (52%) than in the antidepressant group (82%), despite the initial preference for running over antidepressants.

At the end of the trial, around 44% % in both groups showed an improvement in depression and anxiety, however the running group also showed improvements in weight, waist circumference, blood pressure, and heart function, whereas the antidepressant group showed a tendency towards a slight deterioration in these metabolic markers.

“Both interventions helped with the depression to around the same extent. Antidepressants generally had worse impact on body weight, heart rate variability and blood pressure, whereas running therapy led to improved effect on general fitness and heart rate for instance. We are currently looking in more detail for effects on biological aging and processes of inflammation’,” Prox Benninix said.

Physical activity is a good option, but antidepressants still have a role

Prof Benninx noted that it is not a case of one or the other when it comes to treating depression. “It is important to say that there is room for both therapies in care for depression. The study shows that lots of people like the idea of exercising, but it can be difficult to carry this through, even though the benefits are significant. We found that most people are compliant in taking antidepressants, whereas around half of the running group adhered to the two-times-a-week exercise therapy. Telling patients to go run is not enough. Changing physical activity behaviour will require adequate supervision and encouragement as we did by implementing exercise therapy in a mental health care institution.”

She added: “Antidepressants are generally safe and effective. They work for most people. We know that not treating depression at all leads to worse outcomes; so antidepressants are generally a good choice. Nevertheless, we need to extend our treatment arsenal as not all patients respond to antidepressants or are willing to take them. Our results suggest that implementing exercise therapy is something we should take much more seriously, as it could be a good – and maybe even better – choice for some of our patients.  

“In addition, let’s also face potential side effects our treatments can have. Doctors should be aware of the dysregulation in nervous system activity that certain antidepressants can cause, especially in patients who already have heart problems. This also provides an argument to seriously consider tapering and discontinuing antidepressants when depressed or anxious episodes have remitted. In the end, patients are only truly helped when we are improving their mental health without unnecessarily worsening their physical health.”

Source: EurekAlert!

50 Steps a Day Cuts Heart Disease Risk by 20%

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Forget walking 10 000 steps a day – climbing up at least 50 steps a day could significantly reduce the risk of heart disease, according to a new study from Tulane University.

The study, published in Atherosclerosis, found that climbing more than five flights of stairs daily could reduce risk of cardiovascular disease by 20%.

Atherosclerotic cardiovascular disease (ASCVD) along with coronary artery disease and stroke are the leading causes of morbidity and mortality worldwide.

“Short bursts of high-intensity stair climbing are a time-efficient way to improve cardiorespiratory fitness and lipid profile, especially among those unable to achieve the current physical activity recommendations,” said co-corresponding author Dr Lu Qi, professor at Tulane University. “These findings highlight the potential advantages of stair climbing as a primary preventive measure for ASCVD in the general population.”

Using UK Biobank data collected from 450 000 adults, the study calculated participants’ susceptibility to cardiovascular disease based on family history, established risk factors and genetic risk factors and surveyed participants about their lifestyle habits and frequency of stair climbing. Median follow-up time was 12.5 years.

The study found that climbing more stairs daily especially reduced risk of cardiovascular disease in those who were less susceptible. However, Qi said the increased risk of heart disease in more susceptible people could be “effectively offset” by daily stair climbing.

Qi touted the public availability of stairs as a low-cost, accessible way to incorporate exercise into daily routines.

“This study provides novel evidence for the protective effects of stair climbing on the risk of ASCVD, particularly for individuals with multiple ASCVD risk factors,” Qi said.

Source: Tulane University

Yoga Therapy Improves Quality of Life and Cardiovascular Function

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Yoga therapy and lifestyle modifications have been shown to improve heart failure (HF) patients’ quality of life and enhance their cardiovascular function. A new study, presented at the American College of Cardiology Asia 2023 conference, examines the long-term outcomes of yoga therapy to determine the benefit of adding yoga therapy as a complementary treatment in the management of HF. After 12 months, participants with HF receiving yoga therapy continued to show improvement in left ventricular systolic function as well as quality of life.

The study included 75 heart failure patients (aged 30–70 years old) at a tertiary care centre in South India, who underwent coronary intervention, revascularisation or device therapy within in the previous six to 12 months. All of the patients included in the study were less than or equal to New York Heart Association (NYHA) Class III and had been on optimised medical therapy for at least 6 months to 12 months, and had a left ventricular ejection fraction (LVEF) of < 45%.

The interventional group included 35 participants (31 men and 4 women) and 40 (30 men and 10 women) were in the non-interventional (control) group. The interventional group received yoga therapy and guideline-directed medical therapy, while the control group only continued with standard guideline-directed medical therapy. Echocardiographic parameters were compared at various follow-ups to see the impact of yoga therapy on heart failure patients.

“Yoga is a combination of mind-body techniques, which is a set of physical exercises [asana] with breathing techniques [pranayama], relaxation and meditation that can be effectively used to stimulate physical and mental well-being,” said lead author Ajit Singh, PhD, research scientist for the Indian Council for Medical Research at Kasturba Medical College & Hospital, Manipal Academy of Heart Education in Manipal, India. “Our patients observed improvement in systolic blood pressure and heart rate compared to patients who were on medication without yoga.”

Participants in the yoga group were taken to the Department of Yoga at the hospital and an experienced yoga therapist taught selected yoga therapy like pranayama, meditation and relaxation techniques. Each session lasted around 60 minutes and participants were supervised for one week at the training centre before being asked to continue self-administered yoga at home. Those in the yoga group were advised to perform yoga at least five days a week for 12 months. At the training centre all the participants were taught together to perform the same steps, but individual support was available.

Researchers measured quality of life improvements using the World Health Organization Quality of Life questionnaire, which uses 26 questions to evaluate quality of life in four aspects: physical, psychological, social and environmental health. The participants completed the questionnaire at enrolment, as well as at 24 weeks and 48 weeks of follow-up. According to the researchers, the study showed participants in the yoga group had improvement in endurance, strength, balance, symptom stability and quality of life. They also observed that while patients improved physically and psychologically, there was no improvement in social and environmental health.

Echocardiographic parameters did not show any significant differences between the two groups at baseline. At both the six- and 12-month follow-up, improved biventricular systolic function was seen in the interventional (yoga) group compared to the control group. The interventional group also showed substantial improvement in functional outcomes as assessed by NHYA classification.

“This study proves that the addition of yoga therapy to standard medical management of heart failure leads to an improvement in left ventricular systolic function and quality of life in heart failure patients,” Singh said. “Hence, yoga therapy may improve physical well-being and left ventricular function among heart failure patients on guideline-directed optimal medical therapy.”

Source: American College of Cardiology

Even Moderate Physical Fitness Protects Against Atrial Fibrillation and Stroke

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A study in more than 15 000 people has found that even moderate physical fitness is linked with a lower likelihood of developing atrial fibrillation and stroke. Progressively higher levels of fitness also reduced the risk of cardiovascular events. The research is presented at ESC Congress 2023.

Atrial fibrillation is the most common heart rhythm disorder, and patients with the condition have a five-fold higher risk of stroke than their peers. This study examined whether fitness was related to the likelihood of developing atrial fibrillation.

The study included 15 450 individuals without atrial fibrillation who were referred for a treadmill test between 2003 and 2012. The average age was 55 years and 59% were men. Fitness was assessed using the Bruce protocol, where participants are asked to walk faster and at a steeper grade in successive three-minute stages. Fitness was calculated according to the rate of energy expenditure the participants achieved, which was expressed in metabolic equivalents (METs).

Participants were followed for new-onset atrial fibrillation, stroke, myocardial infarction and death. The researchers analysed the associations between fitness and atrial fibrillation, stroke and major adverse cardiovascular events (MACE; a composite of stroke, myocardial infarction and death) after adjusting for factors that could influence the relationships including age, sex, cholesterol level, kidney function, prior stroke, hypertension and medications.

During a median of 137 months, 515 participants (3.3%) developed atrial fibrillation. Each one MET increase on the treadmill test was associated with an 8% lower risk of atrial fibrillation, 12% lower risk of stroke and 14% lower risk of MACE.

Participants were divided into three fitness levels according to METs achieved during the treadmill test: low (less than 8.57 METs), medium (8.57 to 10.72) and high (more than 10.72). The probability of remaining free from atrial fibrillation over a five-year period was 97.1%, 98.4% and 98.4% in the low, medium and high fitness groups, respectively.

Study author Dr Shih-Hsien Sung of the National Yang Ming Chiao Tung University, Taipei, Taiwan said: “This was a large study with an objective measurement of fitness and more than 11 years of follow up. The findings indicate that keeping fit may help prevent atrial fibrillation and stroke.”

Source: European Society of Cardiology

Mediterranean Lifestyle Linked to Lower Risk of All-cause and Cancer Mortality

in Mayo Clinic Proceedings.

People who adhere to a Mediterranean lifestyle, which involves a plant-rich diet, adequate rest, physical activity and socialisation, have a lower risk of all-cause and cancer mortality, according to a new study in Mayo Clinic Proceedings. People who adhered to the lifestyle’s emphasis on rest, exercise, and socialising with friends had a lower risk of cardiovascular disease mortality.

While many studies have established the health benefits of a Mediterranean diet and lifestyle, there are few studies on the diet outside of its region of origin. “This study suggests that it’s possible for non-Mediterranean populations to adopt the Mediterranean diet using locally available products and to adopt the overall Mediterranean lifestyle within their own cultural contexts,” said lead author Mercedes Sotos Prieto, Ramon y Cajal research fellow at La Universidad Autónoma de Madrid and adjunct assistant professor of environmental health at Harvard Chan School. “We’re seeing the transferability of the lifestyle and its positive effects on health.”

Led by La Universidad Autónoma de Madrid and Harvard T.H. Chan School of Public Health, the study analysed the habits of 110,799 members of the UK Biobank cohort, a population-based study across England, Wales, and Scotland using the Mediterranean Lifestyle (MEDLIFE) index, which is derived from a lifestyle questionnaire and diet assessments. Participants, who were between the ages of 40 and 75, provided information about their lifestyle according to the three categories the index measures: “Mediterranean food consumption” (intake of foods part of the Mediterranean diet such as fruits and whole grains); “Mediterranean dietary habits” (adherence to habits and practices around meals, including limiting salt and drinking healthy beverages); and “physical activity, rest, and social habits and conviviality” (adherence to lifestyle habits including taking regular naps, exercising, and spending time with friends). Each item within the three categories was then scored, with higher total scores indicating higher adherence to the Mediterranean lifestyle.

The researchers followed up nine years later to examine participants’ health outcomes. Among the study population, 4247 died from all causes; 2401 from cancer; and 731 from cardiovascular disease. Analysing these results alongside MEDLIFE scores, the researchers observed an inverse association between adherence to the Mediterranean lifestyle and risk of mortality. Participants with higher MEDLIFE scores were found to have a 29% lower risk of all-cause mortality and a 28% lower risk of cancer mortality compared to those with lower MEDLIFE scores. Adherence to each MEDLIFE category independently was associated with lower all-cause and cancer mortality risk. The “physical activity, rest, and social habits and conviviality” category was most strongly associated with these lowered risks, and additionally was associated with a lower risk of cardiovascular disease mortality.

Source: Harvard T.H. Chan School of Public Health

Optimum Heart Rate for Fat Burning can Vary Widely among Individuals

The study uncovered individual variations in fat burning during exercise. Graphs of two people’s fat burning curves highlight differences in fat burning rates at varying exercise intensities and demonstrate that fatMAX falls outside the predicted ‘fat burning zone’. Credit: Hannah Kittrell, Mount Sinai Physiolab and AIMS Lab at Icahn Mount Sinai

The ‘fat burning zone’ on commercial exercise machines often does not line up the best heart rate for burning fat as it differs for each individual, Icahn School of Medicine at Mount Sinai researchers report.

Instead, the researchers said, clinical exercise testing (a diagnostic procedure to measure a person’s physiological response to exercise) may be a more useful tool to help individuals achieve intended fat loss goals. The study, which used a machine learning-based modelling approach, was published online in Nutrition, Metabolism and Cardiovascular Disease.

“People with a goal of weight or fat loss may be interested in exercising at the intensity which allows for the maximal rate of fat burning. Most commercial exercise machines offer a ‘fat-burning zone’ option, depending upon age, sex, and heart rate,” says lead author Hannah Kittrell, MS, RD, CDN, a PhD candidate at Icahn Mount Sinai. “However, the typically recommended fat-burning zone has not been validated, thus individuals may be exercising at intensities that are not aligned with their personalised weight loss goals.”

The term FATmax is sometimes used to represent the exercise intensity and associated heart rate at which the body reaches its highest fat-burning rate during aerobic exercise. At this point, fat is a significant fuel source and therefore this intensity may be of interest to those seeking to optimize fat loss during workouts.

As part of the study, the researchers compared heart rate at FATmax, as measured during a clinical exercise test, to predicted heart rate at percentages of maximal effort within the typically recommended ‘fat-burning zone’. In a sample of 26 individuals, the researchers found that there was poor agreement between measured and predicted heart rate, with a mean difference of 23 beats per minute between the two measures. This suggests that general recommendations for a ‘fat-burning zone’ may not provide accurate guidance.

Next, the researchers plan to study whether individuals who receive a more personalised exercise prescription demonstrate more weight and fat loss, as well as improvement of metabolic health markers that identify health risks like type 2 diabetes, obesity, and heart disease.

“We hope that this work will inspire more individuals and trainers to utilise clinical exercise testing to prescribe personalised exercise routines tailored to fat loss. It also emphasises the role that data-driven approaches can have toward precision exercise,” says senior author Girish Nadkarni, MD, MPH, Professor of Medicine at Icahn Mount Sinai.

Source: The Mount Sinai Hospital / Mount Sinai School of Medicine