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It has been a pretty hot topic since the start of the pandemic; What are the comorbidities of Covid-19? The further we go into this pandemic, the more we know about who is at risk. More importantly, we know how we can help alleviate that risk. However, the warning signs have been there before when it comes to our general health. All of the research is showing the escalating risk of hospitalisations and deaths from Covid-19 to those overweight or obese. So why is the topic still the elephant in the room? Rather than honest and open conversations about the risks of living with obesity.

There is, and always has been, a huge stigma around the words ‘fat’, ‘overweight’ and ‘obese’. We are in an industry that is trying to tackle obesity and unhealthy lifestyles, and yet even writing this blog outlining the risks of obesity in the current pandemic, we run the risk of it being taken the wrong way.

This just outlines the uphill battle we face as a society in tackling obesity.

The purpose of this blog is to not only highlight the risk. It is also to understand why being overweight or obese increases the risk of hospitalisation and death from Covid-19. If we truly want to help and get our message across, there’s no point highlighting it without helping to understand why this occurs. So, if you think being obese is just about how someone looks, it is far from that.

We don’t judge people for how they look on the outside. Our concern is what is happening inside the body, where the real damage is occurring. 


NHS statistics in 2018 showed that over a quarter of UK adults are obese and 63% are overweight or obese. This number has doubled since 1993. This has resulted in obesity costing the UK £6.1 billion per year, and £27 billion as a wider society. This is taking into account the further health risks of obesity on issues like type 2 diabetes, hypertension and certain cancers.

In 2019, there were 876,000 hospital admissions where obesity was recorded as the primary or secondary diagnosis. That is 2,400 hospital admissions per day.

The most concerning numbers are the rise in child obesity. According to Public Health England 2015 statistics, 28% of children between ages 2-15 are either overweight or obese. Even children aged 4 to 5, nearly 10% are obese and another 12.8% are overweight.

The amount the UK spend is astronomical. How they spend that money could be criticised, as strategies time and time again have been delivered to almost zero effect.

However, the general changes in our lifestyles since 1993 that have contributed to obesity levels doubling should be on us. 




Firstly, let’s start with how obesity is measured in most scientific studies. The simplest way of measuring is through BMI (body mass index). A calculation of a persons weight compared to height is how BMI measurements are taken. Every PT reading this is rolling their eyes at the mention of BMI. It is a measurement that has received a lot of criticism. Mainly because it does not take into account what amount of our body mass is fat, and what is our skeletal system (muscle and bone).

This is where the measurement can certainly be improved. As the population of people lifting weights and sports people may have a relatively low amount of body fat with higher muscle mass, but still be classed as overweight on a BMI scale. This can be improved slightly by taking a waist measurement. The NHS recommend a weight loss strategy if your waist is 94cm+ for men and 80cm+ for women. So, if your BMI classes you as overweight but you have a good amount of muscle mass and your waist is below these numbers, then there is a good chance you are not overweight.

Despite this, BMI is a useful measurement for the general population. As it is so simple to measure and very non-invasive. This makes it relevant to research studies that require hundreds or even thousands of participants, particularly if the cohort are mainly the general population. Below are the classifications of BMI from underweight to extremely obese.


The effect of being overweight or obese is a health issue regardless of Covid-19. The metabolic stress it puts on the body puts us at risk of many illnesses and diseases. We store excess fat in the wrong places, mainly around key organs such as the liver and lungs. This impairs their function and makes them have to work harder. The extra fat in skeletal muscle and liver can disturb our metabolic function by increasing insulin levels in the blood. This reduces our ability to control those insulin levels, hence why it makes us more at risk of diabetes.

The information we have on Covid-19 is only going to be as strong as it can be after 12 months. We will start with what we have learnt from other outbreaks such as SARS-CoV from 2002 and Swine Flu (H1N1) from 2009. This shows that the warning signs have been here for a long time.

Studies on Swine Flu showed that both the amount of virus shed within the body and the duration of virus shed increased in obese individuals compared to lean individuals (graph below).

An American study in 2009 revealed that in California, 51% of all adult Swine Flu cases were in those with obesity. This resulted in 61% of all deaths occurring in obese individuals.

The main mechanisms behind why overweight and obese individuals may suffer more from these types of viruses are mainly based around the bodies inflammatory state. This can inhibit the immune systems response to the virus. We will go into the mechanisms in a little more detail later.


Now for the main event. So far, we have found the most common comorbidities associated with severe symptoms and mortality to be older ages (65+), obesity, hypertension, diabetes and various cardiovascular diseases. Out of these, I think it’s safe to say that obesity is the one that we can do something about. Especially as obesity also makes someone more susceptible to hypertension, diabetes and many CV diseases.

In a study on the first wave of the pandemic (see graph below), it showed that of the critically ill patients with Covid-19, over 70% of those patients were either overweight or obese (BMI >25). This was a bigger contributor than age (being 50+). 

Another Spanish study on the traits of patients admitted to ICU due to Covid-19, found obesity to be the most common comorbidity out of everything (48% of patients).

A systematic review of 75 different studies on Covid-19 was completed last year and the numbers showed the substantial risk for individuals with obesity:

  • 46% more likely to contract Covid-19
  • 113% more likely to be hospitalised from Covid-19
  • 74% more likely to be admitted to ICU from Covid-19
  • 48% more likely to die from Covid-19

The below illustration from a Southern California study also shows the increasing risk ratio associated to a higher BMI. Patients with a BMI measurement of 40-44 had a risk ratio of 2.68 and patients with a measurement greater than 45 had a risk ratio of 4.18. This means they were over 4 times more at risk of death compared to someone with a BMI of 18.5-24. This study also showed that obesity was a big risk factor even for younger adults. Particularly in men under the age of 60, the risk increased significantly and was the most common comorbidity. 


The fact that obesity is a risk factor for contracting Covid-19 and mortality means it can no longer be ignored. It is not about fat shaming; it is about understanding that obesity has far more implications on a persons health than how they look. The main point of this blog is for you to understand why there is an added risk, and what having excess fat can do to your immune system both short-term and long-term.

Firstly, being obese increases our risk of the majority of other comorbidities; Type 2 diabetes, hypertension, cardiovascular disease and heart disease. That increases the risk alone.

Obesity is a metabolic disease. Hormones and nutrients are not controlled appropriately. Hormones like leptin are increased and hyperglycaemia (excess blood glucose) occurs. Both of which have been shown to increase Covid-19 mortality. This lack of blood glucose control can impair immune cell function and blunt the response to a virus or disease. 

We also discussed previously that virus is shed for longer and more intense in obese individuals. The mechanisms by which excess fat affects our immune system, however, is mainly due to inflammation and ‘cytokine storms’.

Interferons (IFNs) are protein molecules and are a type of cytokine. We have anti-viral interferons in our body protecting our immune system. They quite literally “interfere” with viruses in the body and help to stop them taking over our immune cells. One of the reasons obese individuals have a decreased immune response is because they have reduced numbers of these IFN’s protecting their immune system. This coupled with them have an increased number of cytokines like IL-6, which are a pro-inflammatory cytokine (and therefore increase inflammation in cells), put them at a much higher risk of severe infection.

This increase in inflammation is happening in the lungs in particular, especially during infection of a respiratory disease. Hence why obesity is linked to a reduced lung function and chronic obstructive pulmonary disease (COPD).

Cytokine storms are an uncontrolled inflammatory reaction of the immune system to virus or infection. When a person is carrying excess fat, IL-6 cytokines and C-reactive protein levels are increased. These are both signs of inflammation in the body and cells and are very prominent in cytokine storms. If an immune system reacts to infection with these uncontrollable cytokine storms, the response to the virus is elevated and significantly more severe. With obese individuals having higher levels of both of these cytokines circulating, there is more chance of them creating a cytokine storm when they have been infected by a virus. This puts them in danger of hospitalisation and mortality.

All of this coupled with excess fat tissue can put a huge strain on the immune system and cardiovascular system, in particular. Just increasing the amount of fat stored around essential organs, such as lungs, can put the organs under increasing stress. If they are struggling to function already, the increased fat putting pressure on them can exacerbate the issue.


Unfortunately, given the current situation and obesity levels rising year on year, there is no easy way out of this. We have already gone through the crippling costs on the NHS and the number of hospital visits per year due to obesity (876,000 in case you had forgotten).

Over the coming months and possibly years, we will see obesity levels worsen before there’s any chance of improving.

During the first UK lockdown of 2020, a study on 1.6 million people showed the following outcomes.

  • 29% of people increased in weight
  • 34% decreased the amount of exercise they did
  • 35% increased their amount of snacking
  • 19% were eating less healthy than before
  • 27% were drinking more alcohol
  • 29% of smokers were smoking more
  • 42% admitted to being worried about their physical and mental health

That was in a lockdown in spring/summer, I would take a guess to say these numbers have gotten worse in a winter lockdown. These changes in habits are tough to get out of if you have been doing them for months at a time. Pair that with the fact that people have consumed more processed foods during the lockdown too, and it makes a very difficult scenario to just simply snap out of it when restrictions are lifted. Many people have lost jobs and even more have had their earnings reduced. Unfortunately, this lower income is associated with a lower quality of food supply. Partly because these ultra-processed alternatives are cheaper and have a longer shelf life.

The other knock-on effect of obesity is the potential for the Covid-19 vaccines to be less effective. In influenza vaccines this is certainly the case, but hopefully Covid-19 vaccines can still be effective. The main mechanism for why they may not be as effective in obese individuals is because T cell production in response to infection is the key to the vaccines being effective. Unfortunately, T cell responses have been shown to be impaired in obese individuals.


Again, what’s the point in writing this if we didn’t want to try and help in some way. What can we do right now to help this situation, protect our own health, our family’s health and of course our NHS?

Other than the obvious “we need to lose weight”, there are things we can start doing. But it all starts with taking responsibility for our own health.


I would love to see more research done on this side of things, but there a few studies out there. One study showed that in men who were of normal BMI, those that had a low level of CRF had a 163% higher mortality risk than men who were fit.

Other evidence points at CRF improving the inflammatory response of our immune system to Covid-19 infection, even in obese individuals. Exercise and CRF have a positive effect on lung function for starters and help to lower risk of respiratory infections. Exercise can lower chronic inflammation, and also elicit an anti-inflammatory response in the body that combats the usual pro-inflammatory markers you see with infections and viruses.

Therefore, just increasing our fitness levels can help to put our body and immune system in a better state to fight infections and viruses.


We discussed this in a blog right at the start of the pandemic. There is some really promising evidence showing that higher levels of vitamin D in our bodies are associated with a greater protection against Covid-19. Having insufficient levels increased the risk of hospitalisation and mortality greatly. Why we are not doing more to encourage vitamin D intake off the back of this is beyond me. Especially with the evidence of vitamin D improving immune system function in general, but that’s another subject entirely. If you are interested in learning more about this, have a read of our previous vitamin D blog.

One thing is for sure, having sufficient levels of vitamin D along with living an active lifestyle and a good diet will put you in a far better position to fight off the majority of illnesses and viruses. Our digestive system and gut are closely linked to both our brain and immune system. The better we take care of our nutrition, the better our nutrition takes care of our brain and immune system.


This may be slightly controversial to discuss. We touched on it in the introduction but trying to mask this comorbidity is a very dangerous thing to do. We need to be completely open and honest about the people that are risk and encourage them to do something about it. Otherwise, this issue will only worsen.

Mainstream media are partly the culprits here, too. We often see stories of younger adults suffering in hospital with Covid-19, and the headlines will be that the patient has no comorbidities. Unfortunately, when you see the photo of the individual, more often than not that person is obese or at least overweight. This isn’t helping anyone and in fact feeds the problem further.

However, encouragement is what is needed here, not just being blunt and telling people they are at risk. Helping each other to understand that it is more than just how they look, it’s the unbearable pressure it is putting on their body and organs. Despite it being tough to lose a significant amount of weight, it is very possible when people have the right support, and truly want to do something about it.


Now for what we as a health and fitness industry can do. I’m sure this probably isn’t what you’re expecting to hear. We can shout from the rooftops about how gyms help to keep people healthy, both physically and mentally. That is absolutely true, and we are the biggest advocates of that, so please bear with me why I think we need to do more.

There are roughly 10 million people in the UK using gyms, which is around 15% of the population. 63% of the population are either overweight or obese currently, which is about 42 million people. The gym industry has boomed over the last 30 years, yet obesity levels have also soared in that time.

The easiest thing for gyms to do is to get young and fit people to attend. The emergence of budget gyms has made getting fit more affordable for everyone. However, the only ones benefitting from this gym model are generally already healthy and not overweight, they also have an idea of what to do when it comes to exercise and nutrition.

Gyms will always market their product to look cool and modern, to attract that demographic. The people that need gyms the most aren’t even in their thoughts. This is why beginners and overweight individuals feel too intimidated to even start. They feel like they don’t belong there and won’t get any support whatsoever.

Overweight or obese individuals are the ones that need to be coached through the whole process to make positive long-term changes to their health. Budget gyms and health clubs do not do that.

This is just creating a larger gulf between unhealthy, obese individuals and the regular gym-goers.

For this reason, I truly believe our industry is doing the general public a disservice. This could possibly be a reason why the government have dismissed us as part of the solution to this pandemic. All of the data is there to show why staying fit, healthy and not overweight can help to fight Covid-19 and save the NHS billions of pounds per year.

Even before the pandemic, the fitness industry has never been an integral part of a government scheme to promote keeping fit and healthy. There is a lack of trust there that is deeply ingrained.

In order to really make a difference, our industry needs to change for the better. There absolutely is a place for these types of gyms to give people cheap access to great facilities. But are they the right service for the 42 million or so people who are overweight or obese and most likely don’t like going to the gym?

Quality coaching is the answer. Supportive coaches that educate rather than just make clients sweat for an hour. Coaches that help people that don’t necessary like training, or don’t know where to start.

Health and fitness is about living the lifestyle, not about being the strongest or the fastest. It is our job to help people make these positive lifestyle changes, that they can then pass onto their children and improve the next generations health as well as their own.

We also need to make a welcoming environment to all walks of life. Something I am most proud of at GWD Performance is creating that environment to help people to excel, no matter how inexperienced, unfit or struggling mentally. Everyone is running their own race with their own obstacles.

The people that need the fitness industry the most, are the ones least likely to use gyms. We need to do everything we can to make it a positive experience for them. 

We are on a mission to help those that need it most. It is the health and fitness industry after all, it’s about time we stepped up the health side of it and made a difference.




We have heard it all before about how important hydration is to so many aspects of life; health, body composition, performance, concentration. But for some reason it always seems to get neglected. Humans can survive weeks without food but cannot normally go without fluids for more than a few days.

The overall weight of the human body will be on average around 60% water (age & gender dependant). Yet we still underestimate the importance of hydration. In some ways it’s a similar scenario to sleep and recovery. We’ve all heard the dangers of a lack of sleep, yet we still stay up binge watching Netflix.

The purpose of this blog isn’t to scare people into glugging down 8 litres of water a day. It is to understand the basics of the importance of hydration on fat loss, general health and our brains abilities, and understand how we can make some quick improvements.

Water plays a vital role in a number of essential bodily functions. It is present in the process of most chemical reactions in the body, swallowing, lubricating joints, regulating body temperature, hormonal balance, helping the nervous system function and getting rid of waste products. And of course, we have all had a horrible headache before, then once we have some water it disappears.

If Adam Sandler has taught us anything from his movies, it’s the importance of high-quality H2O!


Sounds like a silly question. “Well it’s water, isn’t it?!”.

The main component in maintaining hydration levels is of course water. Water or fluid is also the craving we get when we are thirsty. But there are other components involved in maintaining a healthy hydration status. For example, we get on average around 20% of our fluid intake through food (depending on what food we eat). Many of the nutrients in our intake also have a significant effect on hydration status.

The main components involved are salt (sodium chloride and bicarbonate), potassium, magnesium and calcium. These solutes are what determine our osmolality, which is essentially the concentrations of these solutes in our intracellular and extracellular fluid.

Intracellular fluids are the fluids found inside our body’s cells, extracellular are the fluids found outside our body’s cells. We won’t get too into this detail, but the concentration levels of the solutes mentioned, or osmolality, is also a very important part of our hydration status. Too much or too little of them can also lead to dehydration of some kind.

Therefore, hydration isn’t just about drinking lots of water, it’s also about getting the appropriate amount of these nutrients. This has a vital role to play in the function of the skeletal system, and the moving of fluids and nutrients into and out of cells.


The human body is defined as mildly dehydrated when there is 1% or greater loss of body mass due to fluid loss. Therefore, for a 90kg person, they would be considered dehydrated if they lost 0.9kg of body weight, during exercise for example.

This may sound like quite a lot, particularly if you were trying to lose 0.9kg of fat! But research has shown that the human body can lose this 1% of mass after just 13 hours of consuming no fluids. Research has also shown that we can lose up to 2% in just 24 hours. I imagine at one point or another we have got to the end of the day and realised we have barely eaten and not even had a drink.

That 2% body mass loss from lack of fluids can have some pretty negative effects. Headaches and symptoms of fatigue begin, cognitive function is impaired, so we struggle to perform day to day tasks and concentrate on work. Physical performance begins to reduce too, which we will discuss further.

The long-term consequences of chronic dehydration have also been researched. Maintaining good hydration levels has been shown to reduce the incidence of kidney stones, coronary heart disease, asthma and hypertension. Although more research is required on the long-term effects of dehydration, particularly on certain cancers. It can also be tough to measure long term fluid intake, but the warning signs are there.


The biggest effect we see from lack of hydration is in physical performance. The 2% drop in body mass we discussed earlier has been shown to reduce endurance performance, increase fatigue, decrease motivation and an increased perceived effort. On top of this, during exercise, just drinking when you are thirsty is not enough to stay adequately hydrated. That is why it is important to keep sipping away at fluids throughout the day prior to exercise, but also continue to drink during intense exercise, regardless of whether you feel thirsty or not. This is most relevant when it comes to training in warmer climates of course, and environments where we lose more fluids through sweat and heavy breathing.

Our cognitive performance is also compromised through dehydration. This is possibly the area that affects our day to day living most. Mild dehydration (2-3% loss) can disrupt our mood, decrease concentration, alertness and short-term memory function, particularly in the young and elderly.


As previously mentioned, fluid has a vital role to play in many bodily functions. Did you know that having low fluid levels can even increase your chance of constipation? It is a common treatment to be recommended to those suffering. However, increasing fluid levels only helps this scenario if you are dehydrated.

There is a broad association between chronic dehydration and an increased level of the hormone angiotensin II. An increase of this hormone is linked to many chronic diseases, such as obesity, diabetes, cancer and cardiovascular disease.

Our kidney function also becomes impaired through lack of hydration. The kidney is a key component in removing waste from the body, and regulates the bodies water balance. Adequate fluid is vital for the kidney to perform its task of filtering waste from the bloodstream and excreting it from the body.

Next up, the heart. The way in which the heart may be affected by dehydration is through a decrease in blood volume. Blood volume may be lowered by a loss of body water, normally seen through exercise or lack of fluid ingestion. This, along with moving from laying down to upright, can lead to an increased heart rate and a drop in blood pressure. Fluid intake can help to alleviate this pretty quickly.

Dehydration can also have an effect on our mental health too. The main mechanism for this is the direct link to the stress hormone (cortisol), where it has been shown that even mild dehydration can increase levels in the body. The indirect repercussions of this can be just as harmful, however. This increased feeling of stress can lead to making poor decisions when it comes to nutrition, lower our motivation to exercise and eat well, and make us feel more tired in general.


This is something we regularly stress to clients when they start working with GWD Performance, and it is possibly the point that gets met with the most scepticism. How can consuming more water help with fat loss?

A 2014 study was conducted on overweight females. The participants were instructed to continue their food and fluid intake as normal, but to drink an extra 1.5L of water per day; 0.5L 30 minutes before breakfast, lunch and dinner.

Despite the increase in fluid intake, at the end of the 8-week study on average there was a significant reduction in body mass, body fat percentages, BMI, and there was also a reported suppression of appetite.

Another 2003 study looked at the effect of having water with a meal compared to various different beverages, including milk, juice and sugar sweetened beverages. Having the various beverages increased total energy intake by anything between 5 and 25% compared to having just water.

There are other mechanisms by which staying hydrated can help with fat loss and body composition levels. The study discussed above showed that consuming more water prior to eating can help to suppress appetite and help prevent overeating.

For someone that tends to consume calories from fluids (fizzy drinks, juice etc.), consuming more water can prevent you from doing just that. The more water you consume, the less thirst you will feel for these calorific drinks, and therefore can naturally reduce daily calorie intake, all by just making a slight change to a habit.

As discussed previously, our kidneys are vital to us removing waste from the body. Adequate hydration is very important in keeping our kidneys working effectively. The simple process of urinating is a removal of waste, and of course water intake has a huge role to play in that, too. This, combined with all of the general health benefits of staying hydrated, are going to keep the body optimal for exercise and energy levels. The more we feel motivated and energetic, the more we are going to want to train and stay active. That raised activity level can help to create a more effective energy balance for fat loss.

The healthier you are, the more your body and mind is prepared to stay active, positive and motivated.


This is a tough one because every persons fluid intake will be unique to them. But there have been a few changes to recommendations over the years, mainly due to poor guidelines previously.

US guidelines, for example, were based on the average amount of fluid intake of the population and did not take into account whether that population were dehydrated or not! We always say as a general rule of thumb, on an average day, females should consume at least 2.5L of water per day and males at least 3L per day.

If we take weight into it, I would recommend consuming 20ml per pound of body weight. So therefore, if you weigh 150lb (around 68kg), then you should be drinking 20mlx150, which equals 3L per day. This may work out a little more than our general numbers above but is a little more accurate based on a persons weight.

However, there are so many factors involved in hydration levels. Activity levels can be a factor, how much we sweat, air and body temperature, what type of foods are consumed, the list goes on.

With all the technology out there these days, the best way to self-measure hydration levels is the good old-fashioned way; urine colour! You can get colour charts to do a daily check to make sure you are hydrated, it’s not the prettiest way but it’s great instant feedback to make changes quickly if you need to.


  1. Always have a water bottle with you. It’s so easy to not drink when you don’t have one available all the time.
  2. Try the water bottles with time markers on. They may look a bit gimmicky, but it gives you a target to aim for all the time.
  3. Keep chipping away at your daily target. Don’t rely on glugging down 1L at a time, keep sipping throughout the day.
  4. Start your day with a glass of water and get ahead of your target from the off. Sip down 500ml when you wake up, it may also help to wake you up (especially if it’s cold).
  5. Have a glass of water 30 minutes before your main meals, it may help to suppress appetite.
  6. If you’re exercising, take that into account and try to get more fluids in BEFORE you exercise, rather than trying to play catch-up after.
  7. Add some flavour. Squeeze a citrus fruit into your bottle or add some berries to add a bit of taste. Even a little bit of squash is fine if it means you drink more.
  8. Don’t forget your electrolytes. We mentioned it in the blog, these are vital to keeping hydrated too.
  9. Keep checking your urine! If it ain’t clear, it ain’t right.
  10. Caffeinated drinks and alcoholic drinks can have a slight diuretic effect. If you’re drinking them, make sure you have a glass of water along with them.
  11. Try and drink most of your fluids before the evening. Nobody wants to be getting out of bed 5 times a night!




At a time when we are doing anything we can to stay on top of our health, we like to pass on anything we feel can help. We look at all aspects of health and wellbeing both practically and in research, try and find what works best and deliver this information to you that we really feel you could benefit from. So please, can I ask that you read this with an open mind. Really start thinking about small changes you can make for your health, fitness and performance just by slightly altering something you already do every minute of every day. If somethings worth doing, it’s worth doing right.

Our respiratory system is a hot topic currently with Coronavirus having such a big impact on our lungs. So other than exercising to make our respiratory and cardiovascular system healthy and strong, what other small changes can we make day in, day out to give us the best possible foundation to stay healthy?

The way we breathe is one of those aspects we feel can help at the moment and is so often overlooked. Obviously, it is too early to have any evidence of the effect of breathing techniques on Covid-19. But as always, we listen to the leaders in their field and make our logical conclusions. The information below, however, can be beneficial in both current circumstances and long-term.

I have discussed breathing techniques in previous blogs and posts. They are something I use every day; they are simple enough for anyone to do and with the current circumstances they have just gone up on my priority list! I’m sure some of you are reading this thinking “I know how to breathe; if I didn’t, I wouldn’t be alive”. Touché, but what most people are doing now is exactly that – they are breathing to survive, not for better health and performance. There are subtle changes we can all make instantly to both improve our mental and physical health, but also make a marginal gain that may well be very important to our immune system.

So, would it be ok if I ask you to stop reading and just breathe for 30 seconds before you read the rest of this article? Really pay attention to how you breathe, how quick your breaths are and if you’re using your nose or mouth.


You have just taken 30 seconds to concentrate on your breathing. How did you breathe, was it exclusively through your nose or was some of it through your mouth?

Did you know that how you breathe as a child can have a big impact on both your looks and cognitive function? We have always been told to breathe in through our nose and out through our mouth, but there is no significant evidence of why this is recommended. We should ALWAYS be breathing through our nose, whether inhaling or exhaling. Even when we are training, the goal should always be to breathe through our nose. The mouth performs zero breathing functions, no medical textbooks identify the mouth as breathing apparatus.

Chronic mouth breathing in children has shown to narrow the upper jaw (maxilla) into a V-shape rather than a wider U-shape. This results in a change in aesthetic and function, the mouth becomes crowded and too small for the tongue. This results in crooked teeth and also forces the lower jaw to be pushed back. Children who breathe solely through the mouth have also been shown to be daydreamers in school and have reduced cognitive ability. In the extreme, a systematic review of literature in 2016 showed that 80% of research has shown chronic mouth breathers to have a higher incidence of learning difficulties.

Having a well-developed maxilla improves the nasal airway and breathing performance. Breathing solely through the nose helps to activate the diaphragm breathing muscles (more on diaphragmatic breathing later). It also has been shown to increase oxygen uptake in the blood, and in turn increase oxygen uptake in the cells by 10%. Now think of the impact that could have on performance and recovery alone.

A 2018 study took recreational athletes for 6 months. 50% of the group were taught to nasal breathe even during exercise, the other 50% did not. The nasal breathing group had an average breathing rate of 39 breaths per minute compared to the other groups 49 breaths per minute. They were able to complete the same amount of exercise and intensity with 22% less breathing ventilation.


When the World Health Organization call stress “The health epidemic of the 21st Century” and it costs USA businesses around $300 billion per year, you know things need to change! Certainly, more things need to change than the way we breathe, but let’s look at how it can help.

Breathing through the mouth initiates our fight or flight response. The shallow and fast breathing that we perform when mouth breathing is what triggers this response. This in turn triggers the release of cortisol, also known as the stress hormone. If we are at work or training and already stressed and releasing cortisol, what do we think is going to happen to our stress levels when we increase that even further just by the way we breathe?

Breathing slow and deep through the nose and initiating the diaphragm can help to calm the mind and reduce the release of cortisol. In turn helping to reduce stress levels and improve sleep performance. If you have read and watched our previous posts, you know how highly we value sleep in health and stress management.

You may think that it’s too late for you to change as you have been breathing the way you have for 30,40 or 50 years. But changing your breathing habits NOW can have a huge impact on how you manage stress. People aged 40+ are most likely to breathe through their mouth whilst sleeping, which reduces oxygen uptake in the time that it’s most important to help recover. If you wake up regularly with a dry mouth, chances are it is because you are mouth breathing all night, which dries your mouth up. There are techniques that can be done to decongest the nose and reduce mouth breathing at night, which we will go on to later. And if you get used to just nasal breathing in the day, you will have a better chance of not doing it in your sleep.


On this topic of breathing techniques, the most renowned in the field that you may have heard of is Wim Hof. He is known as the Iceman for various feats in freezing conditions, such as the world record for distance swimming under ice.

Despite Wim Hof’s achievements and best-selling books, I have recently favoured another leader in the field in Patrick McKeown. I was made aware of him by a friend a while back and have been reading his work ever since. Both have similar breath holding techniques, but I have found Patrick McKeown’s methods to be a little more practical and evidence based. The main difference being that McKeown appreciates the positive role carbon dioxide has to play in breathing performance, as it is the main stimulus for our breathing, not oxygen.

Patrick McKeown recently put his perspective on the role breathing has to play on our immune system and fighting viruses.

Firstly, the facts we all know about nasal breathing;

  • The nose is the first line of defence against airborne viruses
  • It acts as a filtration device for air entering the body
  • Regulates air temperature coming into the body

The biggest effect nasal breathing can have on our immune system is based around its ability to generate nitric oxide, however. Nitric oxide produced in the nasal cavity is carried into the lungs, it helps to open up your airways and redistributes blood around the lungs. Nitric oxide is important for our immune system because it sterilises the air coming into the body, which could help with fighting viruses being inhaled. If we do not breathe through our nose, the nitric oxide in the nasal cavity goes unused, and therefore the first line of our bodies defence against the virus is breached without even a fight.

As stated previously, it is too early for any research to be done on Coronavirus and nasal breathing, but a 2013 study on influenza stated that nitric oxide production through nasal breathing had been proven to prevent influenza viruses. Another study in 2005 was published just after the SARS outbreak, and found that Nitric oxide had a key role to play in stopping the virus being spread when the body first comes into contact with the virus.

Therefore, we cannot conclude that nasal breathing can have the same positive effect on Coronavirus, but if Influenza and another similar virus that affects the respiratory system can be inhibited by it, then we should be taking notice at the very least.


Breathing techniques and exercises are a great way to improve the quality of your breathing, and also get used to breathing through your nose solely.

Mentally they are a great way to unwind, also. If like me you struggle to switch your brain off enough to meditate, then breathing techniques are the next best thing. In fact, they are a form of meditation, as they take your mind away from all the days stressors and get you thinking in the present, concentrating on breathing and only breathing.

Measurement – Bolt Score:

First of all, let’s go with a measurement technique called the Bolt score. It measures breathing volume and breathlessness. This works slightly differently to other tests, where you hold your breath AFTER you breathe out. This is to test your tolerance to carbon dioxide, as I said earlier this is the main driver behind our breathing. The longer you can hold your breath in this test, the more tolerant you are to carbon dioxide and the less air your lungs will need to breathe in.

The International Journal of Sports Physical Therapy found that if you can hold your breath in this test for 25 seconds or higher, there is an 89% chance that dysfunctional breathing is not present.

Below is a link to an instructional video to perform the test:

Diaphragmatic Breathing:

You have probably heard me talk about this one quite a lot. Take a second to watch your body as you breathe. Is it your chest that’s moving the most or is it your stomach/trunk?

Your diaphragm is a thin muscle at the bottom of your lungs and top of your abdomen. Using our diaphragm to breathe allows a greater capacity for the lungs and creates intra-abdominal pressure, which is essentially what is required for us to brace our core. That’s why it transpires over to our training too as bracing of the core is key to our strength in so many ways.

It is also a great stress reliever too. If you take 10 minutes out of your day to practice this, it can be a really positive way to reduce stress. It is as close as I can get to meditation, it clears the head and has been shown to lower our stress hormone levels (cortisol).

Below is a very simple illustration of how to start practicing diaphragmatic breathing, although it takes some time to get used to. We will do our own video on this soon to give you a better idea, but take a look at this one for now. The only thing I would change from the video is to make sure you breathe through your nose in both inhalation and exhalation.

Nasal Decongestion:

Some of you may be thinking that this is all well and good but you often have a blocked up or congested nose. Me too!

Here is a great little tool to decongest the nose, and only takes a few minutes.

Breath Holding:

This is potentially the most powerful for our fitness and performance and fighting off any long-term respiratory problems. 

Hypercapnic-hypoxic training is where we reduce the amount of oxygen in our body and increase the amount of carbon dioxide. We do this by taking a deep breath in followed by a deep breath out. At the very end of our deep breath out, we hold our breath until we feel starved of breath and go back to normal breathing.

This can help to increase our tolerance of carbon dioxide in the body and lower the breathing volume required when we are low on oxygen. Perform this process, then calm your breathing down after and try it again when your breathing is back to normal. Repeat this 5 times, and add on 1 more round after a few days.

This has been shown to increase our Haemoglobin by 5% and increase our capacity to take in oxygen.

I hope you read this with an open mind, and found it useful. If you would like to know more on any of the techniques, or you want the references to any papers I have mentioned then let me know. I don’t like to bombard you with references in a blog like this!