Strength training is as important as cardio – and you can do it from home during COVID-19



Shutterstock

Jason Bennie, University of Southern Queensland; Jane Shakespear-Druery, University of Southern Queensland, and Katrien De Cocker, University of Southern Queensland

We often get bombarded with the message “regular physical activity is the key to good health and well-being”. To most of us, when we hear “physical activity”, we typically think of aerobic exercise such as walking, jogging, and cycling.

But recent evidence suggests muscle-strengthening exercise is very beneficial to our health. In our study, published today, we argue muscle-strengthening exercise deserves to be considered just as important as aerobic exercise.

And the good news is strength training can be done by anyone, anywhere — and you don’t need fancy equipment.

Strength is just as important as cardio

Muscle-strengthening exercise is also known as strength, weight or resistance training, or simply “lifting weights”. It includes the use of weight machines, exercise bands, hand-held weights, or our own body weight (such as push-ups, sit-ups or planking). It’s typically performed at fitness centres and gyms, but can also be done at home.

More than 30 years of clinical research has shown that muscle-strengthening exercise increases muscle mass, strength and bone mineral density. It improves our body’s capacity to clear sugar and fat from the bloodstream, and improves our ability to perform everyday activities such as walking up stairs or getting in and out of a chair. It can also reduce symptoms of depression and anxiety.

In our research, we reviewed the evidence from several large studies and found muscle-strengthening exercise is associated with a reduced risk of early death, diabetes, cardiovascular disease and obesity. Importantly, these health benefits remained evident even after accounting for aerobic exercise and other factors such as age, sex, education, income, body mass index, depression and high blood pressure.

Compared with aerobic exercise like jogging, clinical studies show that muscle-strengthening exercise has greater effects on age-related diseases such as sarcopenia (muscle wasting), cognitive decline and physical function.

This is particularly significant considering we have an ageing population in Australia. Declines in muscle mass and cognitive function are predicted to be among the key 21st-century health challenges.

Most of us don’t even lift — but we should

While the health benefits of muscle-strengthening exercise are clear, the reality is most adults don’t do it, or don’t do it enough. Data from multiple countries show only 10-30% of adults meet the muscle-strengthening exercise guidelines of two or more days per week. Australian adults reported among the lowest levels of strength training in the world.

Our data from more than 1.6 million US adults show nearly twice as many do no muscle-strengthening exercise at all, compared with those who do no aerobic exercise.

The reasons fewer people do strength training than aerobic exercise are complex. In part, it might be because muscle-strengthening exercise has only been included in guidelines for less than a decade, compared with almost 50 years of promoting aerobic exercise. Strength training therefore has been considered by some physical activity and public health scientists as the “forgotten” or “neglected” guideline.

Other factors that may contribute to fewer people doing strength training include the fact it:

  • involves a basic understanding of specific terminology (sets and repetitions)

  • often needs access to equipment (resistance bands or barbells)

  • requires confidence to perform potentially challenging activities (squats, lunges and push-ups)

  • and risks the fear of judgement or falling foul of social norms (such as a fear of excessive muscle gain, or of getting injured).

Here’s how to get started

Unlike most aerobic exercise, strength training can be done at home. It can also be done without extensive equipment, using our own body weight. This makes it a great form of exercise during the COVID-19 pandemic, when many people are confined to their homes or otherwise restriced in where they can go.

If you are currently doing no muscle-strengthening exercise, getting started, even a little bit, will likely have immediate health benefits. Guidelines recommend exercising all major muscle groups at least twice a week: legs, hips, back, chest, abdomen, shoulders and arms. This could include bodyweight exercises like push-ups, squats or lunges, or using resistance bands or hand-held weights.

Here are some excellent free online resources that provide practical tips on how to start a muscle-strengthening exercise routine:

An elderly lady lifting some small weights at home
Muscle-strengthening exercise can be performed by anyone, anywhere. And its health benefits rival, and often exceed, aerobic exercise.
Shutterstock

Governments need to step up

Many people find aerobic exercise difficult, impossible or simply unpleasant. For these people, strength training provides a different way to exercise.

The evidence supporting the health benefits of muscle-strengthening exercise, coupled with its low participation levels, provides a compelling case to promote this type of exercise. But historically, physical activity promotion has generally focused on aerobic exercise.

If governments expect more people to do muscle-strengthening exercise, they need to provide support. One strategy may be to provide affordable access to community fitness centres, home-based equipment and fitness trainers. And media campaigns endorsing muscle-strengthening exercise could also be important for challenging negative stereotypes such as excessive muscle gain. It’s unlikely any of these strategies will be successful individually, so we’ll have to tackle the problem on a few different fronts.The Conversation

Jason Bennie, Senior Research Fellow, University of Southern Queensland; Jane Shakespear-Druery, Accredited Exercise Physiologist, PhD Candidate, University of Southern Queensland, and Katrien De Cocker, Senior Research Fellow, University of Southern Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How much exercise is too much?



Pexels

Paul Millington, University of Bradford; Ally Briggs, University of Bradford; Colin Ayre, University of Bradford, and Jamie Moseley, University of Bradford

The COVID-19 pandemic has made many of us reevaluate our health and take up new exercise regimes. Running and cycling have become increasingly popular as activities that can be carried out by most people without much equipment, while observing social distancing.

There are, of course, a wealth of benefits to cycling and running, but a sudden change in activity levels can put people at increased risk of injury. Muscles, tendons and bones all need time to adapt to increases in activity. And if too much stress is applied strains, tears and even bone injuries – such as stress fractures – can occur.

This shock to the tissues often leads to painful conditions, can thwart people’s well-intentioned plans to exercise and may lead to long-term injury. This can happen anywhere in the body – particularly if you suddenly decide to play two hours of tennis, take an extra-long yoga class or go out for an extra-long run after months of decreased activity.

Injury risk and training loads

Your training should maximise health outcomes while limiting negative consequences, such as injury, illness or fatigue. So how do you know if you are doing too much?

This is where the concept of training loads comes in – which is essentially the impact your training has on the body. Training loads can be affected by lots of things and include factors like how far you run, how long you spend doing yoga or the intensity of your zoom boxercise class.

Young man training in the gym.
It is possible to do too much exercise.
pio3/Shutterstock

To start off, it’s important to think about the amount of energy your new exercise regime requires. This is because the energy available to the human body is like currency – there is a finite supply. And it’s the brain’s job to prioritise how this energy is spent.

Tissues and organs that keep us alive need a constant energy supply and so take priority. The rest of the energy can then be distributed between other bodily functions such as physical activity, mental stress, healing and recovery.

Excessively demanding exercise regimes that don’t allow time for adequate recovery demand high volumes of energy, and this can leave you with an “energy debt”. This is when there is a lack of energy to support the recovery, healing and adaptation of muscles, tendons, the heart, blood vessels and the brain. This puts your body at increased risk of injury.

How to avoid overload

For many, lockdown has been a fantastic opportunity to incorporate regular exercise into their lifestyle and the benefits of this should not be underestimated. But, of course, while it’s generally believed that when it comes to exercise more is better, there can be too much of a good thing.

To try to reduce your risk of injury it’s important to track and analyse your average daily workload. This should be over the course of a week that you can then compare to the previous four weeks This could be in distance or time and is referred to as the acute:chronic workload (ACWL).

There are two methods to analysing the ACWL – one method is to calculate the percentage difference of the most recent week workload average (acute workload) compared to the past four weeks workload average (chronic workload). The second method divides the one-week acute workload by the four-week chronic workload to provide a ratio. This is known as the acute:chronic workload ratio (ACWR).

To reduce the risk of injury, it’s recommended that novice athletes keep any increase in load within a 5% margin over the course of the month. This could extend to a 10% increase for more experienced or higher-performing athletes.

If using the ACWR method, the recommendation is to keep the ratio in the sweet spot between 0.8 and 1.3 and avoid the danger zone of greater than 1.5, as shown in the graph below.

Figure 1. The U Shape relationship between ACWR and injury risk.

The table below shows three examples of both methods with a traffic light system of green for ideal, amber for borderline – with a relatively higher risk of injury – and red for the highest risk.

Table 1. Example workloads.

It’s also important to consider the intensity of your workouts and where possible use your heart rate as a guide to drive a mixture of low- and high-intensity exercise over the course of a week.

You should aim for around four to five low-intensity workouts for every high-intensity workout. This is the training practice of most elite athletes across multiple sports. This allows for better recovery from intense workouts which probably contribute to consistency of training and reduced risk of injury.

Wearable tech, such as Apple watches, Fitbits, Garmin devices, along with apps such as Strava and Runtastic, are also fantastic tools to help you monitor your activity levels and help manage training loads.The Conversation

Paul Millington, Lecturer in Physiotherapy, University of Bradford; Ally Briggs, Lecturer in Sport and Exercise, University of Bradford; Colin Ayre, Lecturer in Physiotherapy, University of Bradford, and Jamie Moseley, Clinical Lead and Lecturer in Physiotherapy, University of Bradford

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Ten tips for looking after your back while you’re sitting down



Shutterstock/LightField Studios

David Byfield, University of South Wales

Working from home is challenging. Apart from reduced social interaction and the domestic juggling involved, homes are not usually designed to replicate a workplace environment when it comes to employees’ health.

Instead, improvised work stations have become the norm for many people, whether it’s a dining table, a sofa, or even a corner of floor space. None of these are ideal for posture or avoiding back and neck pain. In recent weeks, we have had numerous inquiries at the Welsh Institute of Chiropractic from people seeking advice as a result of their new working conditions.

One of the main challenges facing clinicians dealing with these problems is the number of myths and misunderstandings that exist around low back pain – for example, that it is caused by a weak core (it isn’t) or that it will become persistent and get worse in later life (most cases improve).

This is not to say that low back pain is not a serious health issue, because it most certainly is. It is the most common musculo-skeletal condition in the world, with an estimated 577 million cases at any point in time – and is the leading cause of absenteeism from work. This makes low back pain one of the major public health concerns in most countries throughout the world, with a huge impact on their economies.

On the plus side, there are some encouraging facts about the condition that are well supported by clinical research. For example, we now know that a negative mindset and poor coping strategies are associated with persistent pain, while flare-ups are usually related to changes in activity, stress and mood rather than structural damage.

Also, effective care for low back pain is relatively cheap and safe, and can be improved by better physical and mental health, as well as healthy sleep habits and body weight.

When it comes to ideal sitting positions, these are likely to be different for different people – simple generalisations don’t work for everyone. But studies have demonstrated that “postural variability” (changing your position) and regular subtle movements while sitting are important. This could be as simple as regularly crossing and uncrossing your legs – at both the thigh and ankle – or moving to the edge of the chair and back, or side to side. Think of it as fidgeting to stay fit.

This particular point was addressed in a recent investigation, which recruited 90 participants (61 with no history of low back pain, 29 with) who were asked to sit for one hour, while data was collected on back muscle activity, spine posture and pain.

The researchers concluded that sitting-induced back pain does not appear to be due to posture or muscle activity. Instead, it may be related directly to “micro-movement” – such as fidgeting while sitting (what we call “dynamic sitting postures”). Those who developed pain did not sit differently – but they did move less.

Back to work

So what do these findings mean for those of us working from home or sitting for long periods? Wherever you are sitting – at home or in an office – it is vital to keep moving regularly. And, while sitting itself does not actually damage the spinal structures directly, there are significant benefits from limiting uninterrupted sedentary time to around 20 minutes.

Yoga helps.
Shutterstock/fizkes

Equally important is the fact that prolonged sitting reduces blood flow to the brain and decreases cerebro-vascular function, which is associated with lower cognitive ability. Reduction in cerebral blood flow is offset when frequent short-duration walking breaks are included in a sitting period.

Here are ten tips courtesy of the US therapist Kelly Starrett to think about before you next sit down to work.

  1. Learn to breathe from your stomach.
  2. Sit on the edge of your chair.
  3. At home, sit on the floor some times instead of a chair or sofa.
  4. Sit cross-legged when you can (but keep changing the position and leg regularly).
  5. Get up from your chair every 20 minutes.
  6. Stay hydrated to keep your body cool, and assist muscle and joint function.
  7. Try “man-spreading” (stretching your legs outwards while sitting) which helps to maintain and improve hip function and mobility.
  8. Stand up at your desk or elevate your workstation using items such as books or boxes at home.
  9. Take the time to perform a full-range hip movement (using the legs for support) and brace the lower back when standing up and sitting down – this avoids placing stress on the lower back and distributes the movement throughout the entire body
  10. Try yoga and pilates to supplement your exercise regime – both help to maintain and improve flexibility.

The key message is that regular movement of any kind is important for your health – even when you are sitting down.




Read more:
Back pain: four ways to fix bad lockdown posture – by copying astronauts


The Conversation


David Byfield, Professor of Professional Practice, School of Health, Sport and Professional Practice, Faculty of Life Sciences and Education, University of South Wales

This article is republished from The Conversation under a Creative Commons license. Read the original article.

For older people and those with chronic health conditions, staying active at home is extra important – here’s how



Shutterstock

Rachel Climie, Baker Heart and Diabetes Institute and Erin Howden, Baker Heart and Diabetes Institute

Fitbit recently released data showing a global decrease in physical activity levels among users of its activity trackers compared to the same time last year.

As we navigate the coronavirus pandemic, this is not altogether surprising. We’re getting less of the “incidental exercise” we normally get from going about our day-to-day activities, and many of our routine exercise options have been curtailed.

While we don’t know for sure how long our lifestyles will be affected in this way, we do know periods of reduced physical activity can affect our health.

Older people and those with chronic conditions are particularly at risk.




Read more:
How to stay fit and active at home during the coronavirus self-isolation


Cardiorespiratory fitness

To understand why the consequences of inactivity could be worse for some people, it’s first important to understand the concept of cardiorespiratory fitness.

Cardiorespiratory fitness provides an indication of our overall health. It tells us how effectively different systems in our body are working together, for example how the lungs and heart transport oxygen to the muscles during activity.

The amount of physical activity we do influences our cardiorespiratory fitness, along with our age. Cardiorespiratory fitness generally peaks in our 20s and then steadily declines as we get older. If we’re inactive, our cardiorespiratory fitness will decline more quickly.

As we get older, our cardiorespiratory fitness declines.
Shutterstock

One study looked at five young healthy men who were confined to bed rest for three weeks. On average, their cardiorespiratory fitness decreased 27% over this relatively short period.

These same men were tested 30 years later. Notably, three decades of normal ageing had less effect on cardiorespiratory fitness (11% reduction) than three weeks of bed rest.

This study demonstrates even relatively short periods of inactivity can rapidly age the cardiorespiratory system.




Read more:
5 ways nutrition could help your immune system fight off the coronavirus


But the news isn’t all bad. Resuming physical activity after periods of inactivity can restore cardiorespiratory fitness, while being physically active can slow the decline in cardiorespiratory fitness associated with normal ageing.

Staying active at home

Generally, we know older adults and people with chronic health conditions (such as heart disease or type 2 diabetes) have lower cardiorespiratory fitness compared to younger active adults.

This can heighten the risk of health issues like another heart disease event or stroke, and admission to hospital.

While many older people and those with chronic health conditions have been encouraged to stay home during the COVID-19 pandemic, it’s still possible for this group to remain physically active. Here are some tips:

  1. set a regular time to exercise each day, such as when you wake up or before having lunch, so it becomes routine

  2. aim to accumulate 30 minutes of exercise on most if not all days. This doesn’t have to all be done at once but could be spread across the day (for example, in three ten-minute sessions)

  3. use your phone to track your activity. See how many steps you do in a “typical” day during social distancing, then try to increase that number by 100 steps per day. You should aim for at least 5,000 steps a day

  4. take any opportunity to get in some activity throughout the day. Take the stairs if you can, or walk around the house while talking on the phone

  5. try to minimise prolonged periods of sedentary time by getting up and moving at least every 30 minutes, for example during the TV ad breaks

  6. incorporate additional activity into your day through housework and gardening.




Read more:
Why are older people more at risk of coronavirus?


A sample home exercise program

First, put on appropriate footwear (runners) to minimise any potential knee, ankle or foot injuries. Also ensure you have a water bottle close by to stay hydrated.

It may be useful to have a chair or bench nearby in case you run into any balance issues during the exercises.

  • Start with five minutes of gentle warm up such as a leisurely walk around the back garden or walking up and down the hallway or stairs

  • then pick up the pace a little for another ten minutes of cardio – such as brisk walking, or skipping or marching on the spot if space is limited. You should work at an intensity that makes you huff and puff, but at which you could still hold a short conversation with someone next to you


The Conversation, CC BY-ND
  • next, complete a circuit program. This means doing one set of six to eight exercises (such as squats, push ups, step ups, bicep curls or calf raises) and then repeating the circuit three times

    • these exercises can be done mainly using your own body weight, or for some exercises you can use dumbbells or substitutes such as bottles of water or cans of soup
    • start with as many repetitions as you can manage and work up to 10-15 repetitions of each exercise
    • perform each exercise at a controlled tempo (for example, take two seconds to squat down and two seconds to stand up again)
  • finish with five minutes of gentle cool down similar to your warm up.




Read more:
Every cancer patient should be prescribed exercise medicine


If you have diabetes, check your blood sugar levels before, during and after you exercise, and avoid injecting insulin into exercising limbs.

If you have a heart condition, it’s important to warm up and cool down properly and take adequate rests (about 45 seconds) after you complete the total repetitions for each exercise.

For people with cancer, consider your current health status before you start exercising, as cancers and associated treatments may affect your ability to perform some activities.The Conversation

Rachel Climie, Exercise Physiologist and Research Fellow, Baker Heart and Diabetes Institute and Erin Howden, Group Leader, Baker Heart and Diabetes Institute

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Should you avoid meat for good health? How to slice off the facts from the fiction



Meat is a very popular food for most Americans. Its nutritional value is a topic of much debate.
puhhha/Shutterstock.com

Dariush Mozaffarian, Tufts University

More than half of Americans who make New Year’s resolutions resolve to “eat healthier.” If you’re one, you might be confused about the role meat should play in your health.

It’s no wonder you’re confused. One group of scientists says that reducing red and processed meat is a top priority for your health and the planet’s. Another says these foods pose no problems for health. Some of your friends may say it depends, and that grass-fed beef and “nitrite-free” processed meats are fine. At the same time, plant-based meat alternatives are surging in popularity, but with uncertain health effects.

As a cardiologist and professor of nutrition, I’d like to clear up some of the confusion with five myths and five facts about meat.

First, the myths.

Red meat, while very popular, has not been shown to have health benefits.
Natalia Lisovskaya/Shutterstock.com

Myth: Red meat is good for health

Long-term observational studies of heart disease, cancers or death and controlled trials of risk factors like blood cholesterol, glucose and inflammation suggest that modest intake of unprocessed red meat is relatively neutral for health. But, no major studies suggest that eating it provides benefits.

So, while an occasional serving of steak, lamb or pork may not worsen your health, it also won’t improve it. And, too much heme iron, which gives red meat its color, may explain why red meat increases risk of Type 2 diabetes. Eating red meat often, and eating processed meat even occasionally, is also strongly linked to colorectal cancer.

Myth: You should prioritize lean meats

For decades, dietary guidance has focused on lean meats because of their lower fat, saturated fat and cholesterol contents. But these nutrients don’t have strong associations with heart attacks, cancers or other major health outcomes.

Other factors appear more important. Processed meats, such as bacon, sausage, salami and cold cuts, contain high levels of preservatives. Sodium, for example, raises blood pressure and stroke risk, while the body converts nitrites to cancer-causing nitrosamines. Lean or not, these products aren’t healthy.

Myth: Focus on a ‘plant-based’ diet

“Plant-based” has quickly, but somewhat misleadingly, become a shorthand for “healthy.” First, not all animal-based foods are bad. Poultry and eggs appear relatively neutral. Dairy may have metabolic benefits, especially for reducing body fat and Type 2 diabetes. And, seafood is linked to several health benefits.

Conversely, many of the worst foods are plant-based. Consider white rice, white bread, fries, refined breakfast cereals, cookies and so on. These foods are high in refined starch and sugar, representing 42% of all calories in the U.S., compared to about 5% of U.S. calories from unprocessed red meats, and 3% from processed meats.

Either a “plant-based” or omnivore diet is not healthy by default. It depends on what you choose to eat.

Myth: Grass-fed beef is better for your health

Conventional livestock eat a combination of forage (grass, other greens, legumes) plus hay with added corn, soy, barley or grain. “Grass-fed,” or “pasture-raised,” livestock eat primarily, but not exclusively, forage. “Grass-finished” livestock should, in theory, only eat forage. But no agency regulates industry’s use of these terms. And “free range” describes where an animal lives, not what it eats.

“Grass-fed” may sound better, but no studies have compared health effects of eating grass-fed versus conventional beef. Nutrient analyses show very modest differences between grass-fed and conventionally raised livestock. You might eat grass-fed beef for personal, environmental or philosophical reasons. But don’t expect health benefits.

Myth: Plant-based meat alternatives are healthier

Products like Impossible Burger and Beyond Meat are clearly better for the environment than conventionally raised beef, but their health effects remain uncertain. Most nutrients in plant-based alternatives are, by design, similar to meat. Using genetically engineered yeast, Impossible even adds heme iron. These products also pack a lot of salt. And, like many other ultra-processed foods, they may lead to higher calorie intake and weight gain.

So, what are the facts?

Sausages wrapped in bacon are a double whammy of unhealthy meat, as both bacon and sausage are processed meats.
MShev/Shutterstock.com

Fact: Processed meats are bad for health

Processed meats contain problematic preservatives. Even those labeled “no nitrates or nitrites added” contain nitrite-rich fermented celery powder. A current petition by the Center for Science in the Public Interest asks the FDA to ban the misleading labeling.

Besides the sodium, nitrites and heme, processed meats can contain other carcinogens, produced by charring, smoking or high-temperature frying or grilling. These compounds may not only harm the person who eats these products; they can also cross the placenta and harm a fetus.

Fact: A meatless diet is not, by itself, a healthy diet

Most diet-related diseases are caused by too few health-promoting foods like fruits, nuts, seeds, beans, vegetables, whole grains, plant oils, seafood and yogurt. Additional health problems come from too much soda and ultra-processed foods high in salt, refined starch or added sugar. Compared to these major factors, avoiding or occasionally eating unprocessed red meat, by itself, has modest health implications.

Fact: Beef production is devastating the environment

In terms of land use, water use, water pollution and greenhouse gases, unprocessed red meat production causes about five times the environmental impact of fish, dairy or poultry. This impact is about 20 times higher than that of eggs, nuts or legumes, and 45 to 75 times higher than the impact of fruits, vegetables or whole grains. A 2013 UN report concluded that livestock production creates about 15% of all global greenhouse gas emissions, with nearly half coming from beef alone.

Fact: Plant-based meats are better for the environment

Production of plant-based meat alternatives, compared to conventional beef, uses half the energy, one-tenth of the land and water, and produces 90% less greenhouse gas. But, no studies have yet compared plant-based meat alternatives to more natural, less processed options, such as mushrooms or tofu.

Fact: Many questions remain

Which preservatives or other toxins in processed meat cause the most harm? Can we eliminate them? In unprocessed red meats, what exactly increases risk of Type 2 diabetes? What innovations, like feeding cows special strains of seaweed or using regenerative grazing, can reduce the large environmental impacts of meat, even grass-fed beef? What are the health implications of grass-fed beef and plant-based meat alternatives?

Like much in science, the truth about meat is nuanced. Current evidence suggests that people shouldn’t eat unprocessed red meat more than once or twice a week. Grass-fed beef may be modestly better for the environment than traditional production, but environmental harms are still large. Data don’t support major health differences between grass fed and conventional beef.

Similarly, plant-based meat alternatives are better for the planet but not necessarily for our health. Fruits, nuts, beans, vegetables, plant oils and whole grains are still the best bet for both human and planetary health.

[ You’re smart and curious about the world. So are The Conversation’s authors and editors. You can read us daily by subscribing to our newsletter. ]The Conversation

Dariush Mozaffarian, Dean of Nutrition Science and Policy, Tufts University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Hot and bothered: heat affects all of us, but older people face the highest health risks



Older people’s bodies can’t regulate their temperature as well as younger people’s.
From shutterstock.com

Arnagretta Hunter, Australian National University

Australian summer temperatures have risen by 1.66℃ over the past 20 years. In the past century we’ve seen a significant increase in the number, intensity and duration of heatwaves during our summers.

Heat is the natural hazard associated with the highest mortality in Australia. When heatwaves occur, the death toll routinely reaches into the hundreds. For example, the 2009 heatwave across southeast Australia resulted in close to 500 deaths.

Heat is more likely to endanger the health of people with pre-existing conditions, people who are socially isolated, and people who have limited access to air conditioning. These are often older members of the community.




Read more:
How rising temperatures affect our health


Heat affects people of different ages in different ways

Human body temperature is set at 36.8℃, although our normal temperature can vary slightly and may marginally decrease as we age.

Ambient temperatures well below this prompt us to keep ourselves warm, and as the temperature rises we look for ways to keep ourselves cool.

An important mechanism of cooling is perspiration. As sweat evaporates, it cools our skin. However, humid weather impedes our capacity to cool ourselves in this way.

Heat stress occurs when the body can’t cool itself and maintain a healthy temperature. Heat stress can begin at temperatures around 30℃ when the humidity is high, and at temperatures closer to 40℃ in dry heat.




Read more:
Extreme heat in sport: why using a fixed temperature cut-off isn’t as simple as it seems


Babies and young children are highly vulnerable to the heat because of their small size. They can become dehydrated and develop heat stress more quickly than adults.

This is because they absorb heat faster, and often cannot remove themselves from hot environments. So little ones need to be kept cool and well hydrated (with milk for babies and water for small children) during hot periods.

Babies and young children can become dehydrated more quickly than adults.
From shutterstock.com

While young people and adults face lower health risks from the heat, extended periods of hot weather can adversely affect our mood. One recent study pointed to increased intimate partner violence during heatwaves.

This effect appears to be exacerbated when night time temperatures are also high. High overnight temperatures are associated with increased crime rates, decreased productivity and poorer academic results.

But generally, it’s people over 65 who are at highest risk from the heat.

How does heat affect older people’s health?

The ageing body doesn’t cope with sudden stresses as quickly or effectively as a younger body. For example, an elderly person’s skin does not produce sweat and cool the body as efficiently as a younger person’s skin.

Importantly, heat stress can exacerbate existing health conditions common in older people, such as diabetes, kidney disease, and heart disease. Many heat deaths are recorded as heart attacks.

In short, this is because heat requires our hearts to work harder. In very hot conditions, our blood vessels dilate, increasing our heart rate. For people with abnormal heart function, these hot periods can lead to worsening of their heart failure.

With severe, prolonged heat stroke, heart failure can even develop in people without pre-existing heart disease.




Read more:
To keep heatwaves at bay, aged care residents deserve better quality homes


For people with pre-existing kidney disease, dehydration during hot periods can impact their kidney function. So people with kidney disease need to take extra care to stay hydrated during hot periods.

Dehydration can also affect older people’s blood pressure, making falls more likely.

Further, hot weather can affect blood sugar control for people with diabetes. Heat stress can increase blood sugar levels even in people without diabetes, but is most concerning in those with the condition. Poor blood sugar control is associated with many different diabetes complications including increased risk of infections.

Hot weather can indirectly affect health if the heat means not being able to exercise.
From shutterstock.com

Older people with chronic medical problems usually take regular medications. Some medications can hinder the body’s ability to regulate temperature and make people more susceptible to heat stress.

For example, people with heart failure often take diuretic medications to manage symptoms like swelling and shortness of breath. But increasing diuretic medications in hot weather can cause dehydration, worsening heart failure and often affecting the kidneys.

Added to this, heat stress may cause disorientation, confusion and delirium. This risk is more pronounced for older people with cognitive conditions and dementia.

Social factors and exercise

Socioeconomic factors and isolation can magnify the risk of heat exposure among older people. For example, some pensioners may not be able to afford air conditioning at home.

Being part of social networks can help. One person may recognise if another is unwell, increasing the likelihood of their friend getting medical attention.




Read more:
Health Check: how to exercise safely in the heat


Further, extended periods of hot weather can interrupt our exercise routines. This can be particularly problematic for older people who may be using exercise to manage chronic health conditions.

Regular exercise correlates with improved quality of life in many conditions, including heart failure, chronic obstructive pulmonary disease, depression, diabetes, cognitive impairment and osteoporosis.

When our activity is disrupted for weeks at a time it can be hard to regain previous fitness. This can be especially true for older people, as muscle mass is commonly lost as we age. Periods of inactivity accelerate muscle loss, and regaining strength and endurance is often more difficult in this context.




Read more:
A hot and dry Australian summer means heatwaves and fire risk ahead


Australia’s climate is changing. We’re likely to experience longer periods of hot temperatures, with hotter summers and some extraordinarily high temperatures. This will test our health and our health-care systems. Understanding the challenge ahead can help to reduce the risks.

On a practical level, be aware of spending too much time in hot temperatures, stay hydrated, and know where you can access air conditioning – particularly if power fails. Consider vulnerable relatives, friends and neighbours, especially those of advanced age.The Conversation

Arnagretta Hunter, Physician & Cardiologist, The Canberra Hospital; Clinical Senior Lecturer, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What causes hangovers, blackouts and ‘hangxiety’? Everything you need to know about alcohol these holidays



There’s no way to cure a hangover, even with ‘hair of the dog’.
Louis Hansel

Nicole Lee, Curtin University and Brigid Clancy, University of Newcastle

With the holiday season well underway and New Year’s Eve approaching, you might find yourself drinking more alcohol than usual.

So what actually happens to our body as we drink alcohol and wake up with a hangover?

What about memory blackouts and “hangxiety”, when you can’t remember what happened the night before or wake up with an awful feeling of anxiety?

Let’s look at what the science says – and bust some long-standing myths.

What happens when you drink alcohol?

It doesn’t matter what type of alcohol you drink – or even whether you mix drinks – the effects are basically the same with the same amount of alcohol.




Read more:
Do different drinks make you different drunk?


When you drink alcohol it goes into the stomach and passes into the small intestine where it’s quickly absorbed into the bloodstream.

If you have eaten something, it slows the absorption of alcohol so you don’t get drunk so quickly. That’s why it’s a good idea to eat before and during drinking.

It takes your body about an hour to metabolise 10g, or one standard drink, of alcohol.

(There are calculators that help you estimate your blood alcohol level but everybody breaks down alcohol at a different rate. So these calculators should only be used as a guide.)

What causes memory blackouts?

We all have that friend who has woken up after a big night out and not been able to remember half the night. That’s a “blackout”.

It’s different to “passing out” – you’re still conscious and able to carry out conversation, you just can’t remember it later.

The more alcohol you drink and the faster you drink it, the more likely you are to experience blackouts.

Once alcohol in your blood reaches a certain level, your brain simply stops forming new memories. If you think of your brain like a filing cabinet, files are going straight to the bin, so when you later try to look for them they are lost.

How do I sober up?

If you’ve had too much, there’s no way to sober up quickly. The only thing that can sober you up is time, so that the alcohol can be eliminated from your body.

The caffeine in coffee may make you feel more awake, but it doesn’t help break down alcohol. You will be just as intoxicated and impaired, even if you feel a little less drunk.

The same goes for cold showers, exercise, sweating it out, drinking water, and getting fresh air. These things might help you feel more alert, but they have no impact on your blood alcohol concentration or on the effects of alcohol.

What causes hangovers?

Researchers haven’t identified one single cause of hangovers, but there are a few possible culprits.

Alcohol is a diuretic, so it makes you urinate more often, which can lead to dehydration. This is especially the case if you’re in a hot, sweaty venue or dancing a lot. Dehydration can make you feel dizzy, sleepy and lethargic.

Alcohol can irritate your stomach lining, causing vomiting and diarrhoea, and electrolyte imbalance.

An imbalance of electrolytes (the minerals our body need to function properly) can make you feel tired, nauseated, and cause muscle weakness and cramps.

Hangovers can leave you tired, dehydrated, and with an irritated stomach.
Adrian Swancar/Unsplash

Too much alcohol can cause your blood vessels to dilate (expand), causing a headache. Electrolyte imbalance and dehydration can also contribute to that thumping head the next morning.

Alcohol also interferes with glucose production, resulting in low blood sugar. Not producing enough glucose can leave you feeling sluggish and weak.

Alcohol also disrupts sleep. It can make you feel sleepy at first but it interrupts the circadian cycle, sleep rhythms and REM (rapid eye movement) sleep, so later in the night you might wake up.

It can stop you from getting the quality of sleep you need to wake feeling refreshed.

Why ‘hair of the dog’ doesn’t work

There’s no way to cure a hangover, even with “hair of the dog” (having a drink the morning after). But drinking the next morning might delay the onset of symptoms, and therefore make you feel better temporarily.




Read more:
Monday’s medical myth: you can cure a hangover


Your body needs time to rest, metabolise the alcohol you have already had, and repair any damage from a heavy night of drinking. So it’s not a good idea.

If you drink regularly and you find yourself needing a drink the next morning, this may be a sign of alcohol dependence and you should talk with your GP.

Suffering from hangxiety?

Alcohol has many effects on the brain, including that warm, relaxed feeling after a couple of drinks. But if you’ve ever felt unusually anxious after a big night out you might have experienced “hangxiety”.

Over a night of drinking, alcohol stimulates the production of a chemical in the brain called GABA, which calms the brain, and blocks the production of glutamate, a chemical associated with anxiety. This combination is why you feel cheerful and relaxed on a night out.

Your brain likes to be in balance, so in response to drinking it produces more glutamate and blocks GABA. Cue that shaky feeling of anxious dread the next morning.

What can you do if you wake up with hangxiety?

To ease some of the symptoms, try some breathing exercises, some mindfulness practices and be gentle with yourself.

There are also effective treatments for anxiety available that can help. Talk to your GP or check out some resources online.

If you’re already an anxious person, drinking alcohol may help you feel more relaxed in a social situation, but there is an even greater risk that you will feel anxiety the next day.

Prevention is better than a cure

Have a drink of water between alcoholic drinks.
Marvin Meyer/Unsplash

If you choose to drink this holiday season, the best way to avoid hangovers, hangxiety, and blackouts is to stick within recommended limits.

The new draft Australian alcohol guidelines recommend no more than ten standard drinks a week and no more than four standard drinks on any one day.

(If you want to check what a standard drink looks like, use this handy reference.)




Read more:
Cap your alcohol at 10 drinks a week: new draft guidelines


As well as eating to slow the absorption of alcohol, and drinking water in between alcoholic drinks to reduce the negative effects, you can also:

  • set your limits early. Decide before you start the night how much you want to drink, then stick to it

  • count your drinks and avoid shouts

  • slow down, take sips rather than gulps and avoid having shots.

If you’re worried about your own or someone else’s drinking, call the National Alcohol and other Drug Hotline on 1800 250 015 to talk through options or check out resources online.The Conversation

Nicole Lee, Professor at the National Drug Research Institute (Melbourne), Curtin University and Brigid Clancy, PhD Candidate (Psychiatry) & Research Assistant, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Can you die from a common cold?



shutterstock.
Estrada Anton/Shutterstock

Peter Barlow, Edinburgh Napier University

Most people know that the flu can kill. Indeed, the so-called Spanish flu killed 50 million people in 1918 – more than were killed in the first world war. But what about the common cold? Can you really catch your death?

The cold is a collection of symptoms – coughing, sneezing, a runny nose, tiredness and perhaps a fever – rather than a defined disease. Although it shares a lot with the initial symptoms with the flu, it’s a very different infection.

Rhinovirus causes about half of all colds, but other viruses can cause one or more of the symptoms of a cold, including adenovirus, influenza virus, respiratory syncytial virus and parainfluenza virus.

The rhinovirus causes about half of all colds.
Maryna Olyak/Shutterstock

The common cold is normally a mild illness that resolves without treatment in a few days. And because of its mild nature, most cases are self-diagnosed. However, infection with rhinovirus or one of the other viruses responsible for common cold symptoms can be serious in some people. Complications from a cold can cause serious illnesses and, yes, even death – particularly in people who have a weak immune system.

For example, studies have shown that patients who have undergone a bone marrow transplant can have a higher likelihood of developing a serious respiratory infection. While rhinovirus is not thought to be the main cause of this, other viruses that are associated with symptoms of the common cold, such as RSV, adenovirus and parainfluenza virus, are.

There is, of course, more than one way for someone to become very sick after infection with a respiratory virus. Some viruses, such as adenovirus, can also cause symptoms throughout the body, including the gastrointestinal tract, the urinary tract and the liver.

Other viruses, like the influenza virus, can themselves potentially cause severe inflammation in the lungs, but they can also lead to particularly serious conditions, such as bacterial pneumonia.




Read more:
We have a good chance of curing the common cold in next ten years – a scientist explains


A virus-induced bacterial infection is one way a cold or flu virus can lead to death. While the exact mechanisms of how bacterial infections can be primed by viral infection are still being investigated, a possible way it can occur is through increased bacterial attachment to cells of the lung. For example, rhinovirus has been shown to increase the presence of a receptor called PAF-r in lung cells. This can allow bacteria, such as Streptococcus pneumoniae, to bind more effectively to the cells, increasing the likelihood of it leading to a severe condition like pneumonia.

Higher risk in some people

Unfortunately, a cold can also have more severe symptoms in the very young and the very old. Older people are more likely to develop a more serious infection compared with adults or older children. And people who smoke – or who are exposed to second-hand smoke – are also more likely to get a cold and have more severe symptoms.

Another group of people who are more severely affected by infection with cold-causing viruses are people with an existing lung condition. They can include people with asthma, cystic fibrosis or chronic obstructive pulmonary disease (COPD). Infection with a virus that causes inflammation of the airways can make breathing much harder. People with COPD who catch a mild cold virus are also at risk of developing a bacterial infection.




Read more:
Your lungs are full of microorganisms … and that’s a good thing


While the bacterial infection in these patients can be treated with antibiotics, there is no effective antiviral treatment against all types of rhinovirus. For other respiratory viruses, such as influenza, there is an effective vaccine that can help protect vulnerable people from the flu virus, including asthmatics, the very young and the very old.

There is not one single element that dictates how severe an infection with a cold virus will be, but there are many conditions or factors that can raise a red flag.




Read more:
Flu jab: for asthmatics, avoiding the flu vaccine could be a fatal mistake


One of the best ways to avoid catching a cold is to wash your hands properly. This can prevent the spread of many different infections, not just the viruses that cause the common cold. And everyone, not just those classed as vulnerable, should get the flu jab. For viral infections, prevention is key.The Conversation

Peter Barlow, Professor of Immunology and Infection and Head of Research of the School of Applied Sciences, Edinburgh Napier University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Feeling sick is an emotion meant to help you get better faster



The emotion of lassitude might help your body fight off infection by making certain adjustments.
Kalinka Georgieva/Shutterstock.com

Joshua Schrock, University of Oregon

You know what it’s like to be sick. You feel fatigued, maybe a little depressed, less hungry than usual, more easily nauseated and perhaps more sensitive to pain and cold.

The fact that illness comes with a distinct set of psychological and behavioral features is not a new discovery. In medical terminology, the symptom of malaise encompasses some of the feelings that come with being ill. Animal behaviorists and neuroimmunologists use the term sickness behavior to describe the observable behavior changes that occur during illness.

Health care providers often treat these symptoms as little more than annoying side effects of having an infectious disease. But as it turns out, these changes may actually be part of how you fight off infection.

I’m an anthropologist interested in how illness and infection have shaped human evolution. My colleagues and I propose that all these aspects of being sick are features of an emotion that we call “lassitude.” And it’s an important part of how human beings work to recover from illness.

Your body sets priorities when fighting germs

The human immune system is a complex set of mechanisms that help you suppress and eliminate organisms – such as bacteria, viruses and parasitic worms – that cause infection.

Activating the immune system, however, costs your body a lot of energy. This presents a series of problems that your brain and body must solve to fight against infection most effectively. Where will this extra energy come from? What should you do to avoid additional infections or injuries that would increase the immune system’s energy requirements even more?

Fever is a critical part of the immune response to some infections, but the energy cost of raising your temperature is particularly high. Is there anything you can do to reduce this cost?

To eat or not to eat is a choice that affects your body’s fight against infection. On one hand, food ultimately provides energy to your body, and some foods even contain compounds that may help eliminate pathogens. But it also takes energy to digest food, which diverts resources from your all-out immune effort. Consuming food also increases your risk of acquiring additional pathogens. So what should you eat when you’re sick, and how much?

We humans are highly dependent on others to care for and support us when we’re sick. What should you do to make sure your friends and family care for you when you’re ill?

My colleagues and I propose that the distinctive changes that occur when you get sick help you solve these problems automatically.

  • Fatigue reduces your level of physical activity, which leaves more energy available for the immune system.
  • Increased susceptibility to nausea and pain makes you less likely to acquire an infection or injury that would further increase the immune system’s workload.
  • Increased sensitivity to cold motivates you to seek out things like warm clothing and heat sources that reduce the costs of keeping body temperature up.
  • Changes in appetite and food preferences push you to eat (or not eat) in a way that supports the fight against infection.
  • Feelings of sadness, depression and general wretchedness provide an honest signal to your friends and family that you need help.

Of course these changes depend on the context. Any parents reading this article are likely familiar with the experience of being sick but pushing through it because a child needs care. While it may make sense to reduce food intake to prioritize immunity when the sick individual has plenty of energy reserves, it would be counterproductive to avoid eating if the sick person is on the verge of starvation.

Your body needs you to do (or avoid) a few things so it can concentrate on getting better.
tommaso79/Shutterstock.com

Sickness as an emotion

So how does your body organize these advantageous responses to infection?

The evidence my colleagues and I reviewed suggests that humans possess a regulatory program that lies in wait, scanning for indicators that infectious disease is present. When it detects signs of infection, the program sends a signal to various functional mechanisms in the brain and body. They in turn change their patterns of operation in ways that are useful for fighting infection. These changes, in combination with each other, produce the distinct experience of being sick.

This kind of coordinating program is what some psychologists call an emotion: an evolved computational program that detects indicators of a specific recurrent situation. When the certain situation arises, the emotion orchestrates relevant behavioral and physiological mechanisms that help address the problems at hand.

Imagine you’re walking through the woods, thinking you’re alone, and suddenly you are startled by sounds suggesting a large animal is in the underbrush nearby. Your pupils dilate, your hearing becomes attuned to every little sound, your cardiovascular system starts to work harder in preparation for either running away or defending yourself. These coordinated physiological and behavioral changes are produced by an underlying emotion program that corresponds to what you might think of as a certain kind of fear.

Some of these coordinating programs line up nicely with general intuitions about what makes up an emotion. Others have functions and features that we might not typically think of as “emotional.”

Some psychologists suggest these emotion programs likely evolved to respond to identifiable situations that occurred reliably over evolutionary time, that would affect the survival or reproduction of those involved.

This way of thinking has helped researchers understand why some emotions exist and how they work. For instance, the pathogen disgust program detects indicators that some potentially infectious agent is nearby. Imagine you smell the stench of feces: The emotion of disgust coordinates your behavior and physiology in ways that help you avoid the risky entity.

Another example is the emotion of shame, which scouts for signs that you’ve done something that causes members of your social group to devalue you. When you detect one of these indicators – a loved one rebukes you for doing something that hurt them, say – the experience of shame helps you adjust your mental map of what kinds of things will cause others to devalue you. Presumably you will try to avoid them in the future.

Drawing from the emerging discipline of evolutionary medicine, my colleagues and I now apply the idea of these emotion programs to the experience of being sick. We call this emotion “lassitude” to distinguish the underlying program from the outputs it generates, such as sickness behavior and malaise.

We hope that our approach to lassitude will help solve problems of practical importance. From a medical perspective, it would be useful to know when lassitude is doing its job and when it is malfunctioning. Health care providers would then have a better sense of when they ought intervene to block certain parts of lassitude and when they should let them be.

[ Deep knowledge, daily. Sign up for The Conversation’s newsletter. ]The Conversation

Joshua Schrock, Ph.D. Candidate in Anthropology, University of Oregon

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Hangovers: this is what happens to your body when you’ve had one too many



Elur/Shutterstock

Hal Sosabowski, University of Brighton

Having a few drinks at Christmas is, for some people, as much a part of the festive tradition as presents, decorations or carols. So if you find yourself nursing a hangover on Boxing Day, you might be interested to know what’s actually going on inside your body and why you feel so bad.

We tend to drink because in low doses alcohol is initially a euphoriant, it makes you feel happier. It does this by causing the body to release dopamine and endorphins, chemicals that stimulate the brain’s reward system. But, after a while and as you drink more, it ultimately suppresses some brain activity and slows down your heart and breathing.

The effects of the initial intake of any alcohol is the first of many stages of narcosis, the last of which is death. There just happens to be a large window between an effective dose (which has you thinking you are far more witty and handsome than you actually are and, later, running down the street with a traffic cone on your head) and a lethal dose (which has you on a mortuary slab).




Read more:
Alcoholic? Me? How to tell if your holiday drinking is becoming a problem


Note that even before you arrive at the typical drink drive limit, you might experience excitement, uncoordination, impairment, speech slurring, swaying and loss of inhibition. And yet you’ll still legally be able to drive a car. Small amounts of alcohol affect the limbic system in the brain, which result in aggression and the Friday and Saturday night melees common in many town centres.

Alcohol is also a vasodilator, which means it widens blood vessels, diverting blood from the body’s core to its extremities. This results in the characteristic flushed cheeks you can get from consuming alcohol and also the red nose often sported by dyed-in-the-wool drinkers.

What could possibly go wrong?
Wave break media/Shutterstock

Initially, drinking alcohol is self-reinforcing. What might seem a good idea initially seems an even better idea after you’ve had a few. Alcohol is absorbed quicker than most things since some is absorbed in the stomach (rather than the small intestine). It then spreads throughout the body and is distributed to all organs including the brain and the liver, where the body makes a valiant attempt to break down and dispose of the alcohol.

To do this, the liver produces enzymes, small molecules that help either make or break down important molecules. In this case, the enzyme alcohol dehydrogenase breaks down the alcohol (ethanol) into acetaldehyde (ethanal), which is then further broken down into acetic (ethanoic) acid and then to carbon dioxide.

Energy is also released at all stages of the breakdown, which explains why heavy drinkers can sometimes be overweight. In fact, long-term alcoholics often get most of their calories from alcohol and eat very little. This can make them overweight but curiously undernourished because they are consuming empty calories and no vitamins or protein, which can produce a general appearance and feeling of illness.

Why you vomit

The first stage breakdown product, ethanal, is an emetic, which means it makes you want to vomit. As you drink and become more euphoric, your blood ethanol level is being monitored by the area postrema, the part of your brain which checks your blood for things that shouldn’t be there. If you eat some food which causes vomiting and diarrhoea, it’s your postrema that has instructed your body to get rid of the offending comestibles.

Ethanal has the same effect. The postrema works to very fine tolerances, and as soon as your body contains enough ethanal, and the threshold that nature has set is reached, the postrema instructs your stomach to contract and makes you sick. Trying to stop this is like trying to hold back the tide. You may have noticed the very short time between drinking enthusiastically and realising that it’s a question of when, and not if, you are going to vomit.

Disulfiram (Antabuse) is a drug used to treat chronic alcoholism that stops the subsequent breakdown of ethanal after you drink, causing an immediate hangover and explosive vomiting. It’s effectively a form of aversion therapy.

Hangover causes

Unfortunately, there’s no drug to treat drunkenness itself – or a hangover. Once you are intoxicated you just have to wait it out. The liver can metabolise between 8g and 12g of alcohol in an hour and the only way to become less drunk is to stop drinking so the alcohol can diffuse out of your brain and your liver can complete the breakdown.

Aside from the vomiting, we don’t know exactly why we feel so terrible when we’re hungover, but it is thought to be another effect of ethanal and congeners, the non-alcoholic chemical clutter that is a by-product of fermentation. These include oils, minerals and other forms of alcohol such as methanol (wood alcohol), which can cause you to go blind in high doses.




Read more:
Lining your stomach with milk before a big night out – and other alcohol myths


Darker drinks have higher amounts of congeners. Red wine also causes a particularly vicious hangover since it contains a vasoconstrictor, which constricts your blood vessels and causes that throbbing headache. Meanwhile, vodka might be more forgiving since “pure” vodka is just alcohol and water.

The only other thing that might help reduce your hangover after a heavy drinking session is a glass of water before bed. Alcohol stops your pituitary gland producing the anti-diuretic hormone vasopressin, which normally restricts urine production. This means you end up losing more water than you take in, causing dehydration that irritates the blood vessels, leading to headaches.

Otherwise, you’ll just have to console your post-Christmas blues with roast dinner leftovers and your favourite holiday film.The Conversation

Hal Sosabowski, Professor of Public Understanding of Science, University of Brighton

This article is republished from The Conversation under a Creative Commons license. Read the original article.