Humans and our ancestors have been running for millions of years. Back then, it helped us capture – or avoid becoming – prey. Now, we do it to keep fit, boost mental health, unwind in nature, or play our favourite sport.

But while many of us were taught how to ride a bike, throw and catch a ball, or kick a footy, it seems very few people are ever taught how to run. You might’ve wondered: am I running wrong?

Well, the truth is there’s no one right way to run. Your ideal technique depends on factors such as leg and foot length, muscle mass, and even how springy your tendons are.

It also depends on whether you’re out for your Sunday run or running full pelt in a sprint.

That said, thinking a little more about how to run can make it feel easier and faster, and reduce injury risk.

Here are five basics to keep in mind.

1. Feet: how you land matters

Some of us land on our heels, others on the balls of our feet. If you grew up running barefoot, you’ll more often land towards the forefoot.

Debate rages on which is best. The truth is heel-first striking stresses the knees a bit more while forefoot landing places more impact on the calves and Achilles tendon.

So, if you’re injury prone in one of those areas, it might be worth adjusting your style.

But for healthy runners, there’s no strong evidence one technique is better for injury.

If you’re considering a change, do it slowly over several months, ideally with expert help.

As you run faster, you’ll bounce more in each step. You’ll naturally land more on your forefoot, especially when sprinting.

2. Legs: softer landings and smoother strides

Three things are worth focusing on:

• minimise the twisting of the legs under your body as you land, to reduce strain on knees and ankles
• keep your pelvis level during landings (dropping or rotating it increases injury risk)
• don’t bounce too high; a smooth, low trajectory uses less energy and keeps impacts manageable.

These principles are perfectly demonstrated by Ethiopian former long-distance runner Haile Gebrselassie:

Just keep relaxed, and allow the knees and ankles to flex normally.

If you find your landing style causes stress or pain, consider running with slightly shorter strides.

Then there’s the “leg recovery phase” – when your leg swings forward after push-off. During jogging, we pull the leg forward briefly with our hip muscles, but otherwise it’s a pretty passive task.

In sprinting, however, the faster leg recovery powered by your hip can contribute about 25% of your forward propulsion in each step. So make sure you flex at the hip while you push back into the ground, so your legs act like scissors as they swing.

Also, the faster you run, the more your knee should flex, and the more the foot should rise under you. This helps the leg swing forwards faster.

In other words: pick your feet up more as you pick up the pace.

3. Arms: built-in shock absorbers

During jogging, your arms help with balance, absorbing bumps or stumbles, especially on uneven ground, as seen here: https://www.youtube.com/embed/ifctluuNkXE?wmode=transparent&start=0

They swing mostly passively and act as shock absorbers during jogging; they can’t do their job when they’re stiff. Relaxation is key.

To keep energy cost low, try bending your elbows to keep their mass closer to your shoulder and keep your shoulders relaxed.

When sprinting, your arms become more active. They help stabilise your whole body in the short time your feet are on the ground.

Top sprint coaches often insist the “drive arm” (the arm swinging backwards) contributes to forward propulsion, thanks to physics.

But the limited studies to date suggest the effect on propulsion is moderate; future studies might shed more light.

That said, the fastest sprinters, like Usain Bolt, are renowned for their aggressive backwards arm drive: https://www.youtube.com/embed/D09QkQ8Cyow?wmode=transparent&start=0

See how his drive arm whips backwards with rapid extension of the shoulder and elbow? Meanwhile, the recovery arm – swinging forwards – is more flexed and moves much slower.

4. Torso: lean just a little

When we run, the torso naturally rotates left and right. That’s fine, although when we run faster there should be less rotation. A more aggressive arm swing helps balance out these rotations.

Our pelvis then rotates in the opposite direction to the torso. The twisting helps us balance, but also contributes a little to forward force.

But as we run faster, these rotations should become smaller as we use our arms to balance better. As your speed increases, swing your arms a bit harder and your body, legs and other arm will follow.

Finally, it’s generally accepted that we keep our torso upright when we run relaxed, with only a very slight forward lean.

But if we want to speed up, leaning forward is a great way to accelerate quickly without doing too much tiring muscle work.

And for those with knee troubles, leaning forward a bit might help reduce impact on the knees.

5. Head: a balancing act

You might be tempted to tilt your head down when you run, to watch your feet or in an effort to accelerate forwards.

But during upright (non-sprinting) running, try to keep it in normal position. Rest your head quietly on the top of your shoulders, just as as evolution intended.

During sprinting, try looking about 20 metres in front of you (a slight chin tuck is fine). When jogging, try looking ahead toward the horizon.

Not sure what your own technique looks like? Try asking a friend to take a quick video of you running. Compare it to an experienced runner running at the same speed.

You might be surprised what you notice.

Anthony Blazevich, Professor of Biomechanics, Edith Cowan University

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

Australia has often been called the “allergy capital of the world”.

An estimated one in ten Australian children develop a food allergy in their first 12 months of life. Research has previously suggested food allergies are more common in infants in Australia than infants living in Europe, the United States or Asia.

So why are food allergies so common in Australia? We don’t know exactly – but local researchers are making progress in understanding childhood allergies all the time.

What causes food allergies?

There are many different types of reactions to foods. When we refer to food allergies in this article, we’re talking about something called IgE-mediated food allergy. This type of allergy is caused by an immune response to a particular food.

Reactions can occur within minutes of eating the food and may include swelling of the face, lips or eyes, “hives” or welts on the skin, and vomiting. Signs of a severe allergic reaction (anaphylaxis) include difficulty breathing, swelling of the tongue, swelling in the throat, wheeze or persistent cough, difficulty talking or a hoarse voice, and persistent dizziness or collapse.

Recent results from Australia’s large, long-running food allergy study, HealthNuts, show one in ten one-year-olds have a food allergy, while around six in 100 children have a food allergy at age ten.

In Australia, the most common allergy-causing foods include eggs, peanuts, cow’s milk, shellfish (for example, prawn and lobster), fish, tree nuts (for example, walnuts and cashews), soybeans and wheat.

Allergies to foods like eggs, peanuts and cow’s milk often present for the first time in infancy, while allergies to fish and shellfish may be more common later in life. While most children will outgrow their allergies to eggs and milk, allergy to peanuts is more likely to be lifelong.

Findings from HealthNuts showed around three in ten children grew out of their peanut allergy by age six, compared to nine in ten children with an allergy to egg.

Are food allergies becoming more common?

Food allergies seem to have become more common in many countries around the world over recent decades. The exact timing of this increase is not clear, because in most countries food allergies were not well measured 40 or 50 years ago.

We don’t know exactly why food allergies are so common in Australia, or why we’re seeing a rise around the world, despite extensive research.

But possible reasons for rising allergies around the world include changes in the diets of mothers and infants and increasing sanitisation, leading to fewer infections as well as less exposure to “good” bacteria. In Australia, factors such as increasing vitamin D deficiency among infants and high levels of migration to the country could play a role.

In several Australian studies, children born in Australia to parents who were born in Asia have higher rates of food allergies compared to non-Asian children. On the other hand, children who were born in Asia and later migrated to Australia appear to have a lower risk of nut allergies.

Meanwhile, studies have shown that having pet dogs and siblings as a young child may reduce the risk of food allergies. This might be because having pet dogs and siblings increases contact with a range of bacteria and other organisms.

This evidence suggests that both genetics and environment play a role in the development of food allergies.

We also know that infants with eczema are more likely to develop a food allergy, and trials are underway to see whether this link can be broken.

Can I do anything to prevent food allergies in my kids?

One of the questions we are asked most often by parents is “can we do anything to prevent food allergies?”.

We now know introducing peanuts and eggs from around six months of age makes it less likely that an infant will develop an allergy to these foods. The Australasian Society of Clinical Immunology and Allergy introduced guidelines recommending giving common allergy-causing foods including peanut and egg in the first year of life in 2016.

Our research has shown this advice had excellent uptake and may have slowed the rise in food allergies in Australia. There was no increase in peanut allergies between 2007–11 to 2018–19.

Introducing other common allergy-causing foods in the first year of life may also be helpful, although the evidence for this is not as strong compared with peanuts and eggs.

What next?

Unfortunately, some infants will develop food allergies even when the relevant foods are introduced in the first year of life. Managing food allergies can be a significant burden for children and families.

Several Australian trials are currently underway testing new strategies to prevent food allergies. A large trial, soon to be completed, is testing whether vitamin D supplements in infants reduce the risk of food allergies.

Another trial is testing whether the amount of eggs and peanuts a mother eats during pregnancy and breastfeeding has an influence on whether or not her baby will develop food allergies.

For most people with food allergies, avoidance of their known allergens remains the standard of care. Oral immunotherapy, which involves gradually increasing amounts of food allergen given under medical supervision, is beginning to be offered in some facilities around Australia. However, current oral immunotherapy methods have potential side effects (including allergic reactions), can involve high time commitment and cost, and don’t cure food allergies.

There is hope on the horizon for new food allergy treatments. Multiple clinical trials are underway around Australia aiming to develop safer and more effective treatments for people with food allergies.

Jennifer Koplin, Group Leader, Childhood Allergy & Epidemiology, The University of Queensland and Desalegn Markos Shifti, Postdoctoral Research Fellow, Child Health Research Centre, Faculty of Medicine, The University of Queensland

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