Breathing is an overlooked gateway to optimal health.  When you breathe better you become more energized, more focused, and more calm.  Spending more time on my breathing has taken my meditation to another level and my aerobic workouts have also improved significantly.  I’m less tired, I’m less breathless with exercise, and my endurance with everyday life and all the stressors that come along with it has improved as a result of my breath work.

In our current COVID-19 environment, I strongly believe that improving our breathing at rest and during exercise can help fortify our defenses against a serious COVID-19 infection.  I blogged back in 2016 here on how the Nobel Prize was awarded to Yoshinori Ohsumi for his work in autophagy, a cellular recycling and cleansing process which is one of the central benefits of fasting.  We all know now what a popular and powerful health trend fasting has become.

I think the next great health movement will be around oxygen and once again, the Nobel Prize might be a bellwether.

The 2019 Nobel Prize was jointly awarded to William G. Kaelin Jr., Sir Peter J. Ratcliffe and Gregg L. Semenza for their seminal work in studying how our cellular machinery senses and adapts to changing oxygen availability.

What both of these Nobel Prizes share in common is the concept of hormesis, which is our body’s ability to adapt to an optimal dose of a physiological stressor.  With fasting, this stressor is a specified period of nutrient deprivation which can trigger the aforementioned process of autophagy.  Similarly, strategic doses of oxygen deprivation can also induce powerful adaptive changes such as triggering your kidneys to produce the hormone erythropoietin (aka EPO), which then stimulates your bone marrow to produce more oxygen-carrying red blood cells.

I call the process of limiting oxygen exposure to stimulate a boost in oxygen-carrying capacity and additional beneficial physiological changes, “Oxygen Fasting or OF.”

Elite athletes and their trainers are well aware of the huge performance benefits of this form of hormesis due to oxygen fasting.  In his book Play On, Jeff Bercovici tells the story of Bob Larsen, elite endurance coach and trainer for champion marathoner Meb Keflezighi, who noted that 95 percent of medals won in international competition went to runners who trained at altitude (lower atmospheric oxygen), especially between 7,000 to 8,000 feet, to boost their red blood cell production and oxygen production.

These athletes were the original oxygen biohackers who “hacked” their training environment to gain a tremendous, but legal physiological advantage.  I say “legal,” because there are athletes like Lance Armstrong who decided to inject the EPO mentioned above, directly as a performance enhancing drug (PED), in a practice known as “blood doping.”

Before we move on, I just released version 2.0 of the free Covid-19 survival guide which can be downloaded here.  It has some new video links and resources and includes breathing practices.

Oxygen and COVID-19

I’ve meant to do a post on breathing and oxygen fasting for some time, but COVID-19 has prompted me to take more immediate action.  Why the motivation?  Because COVID-19’s favorite target for devastation is the lungs and the most concerning symptom has been progressive breathlessness and an inability to provide sufficient oxygen to vital tissues, a process we call “oxygenation.”

I have talked to a few COVID-19 patients and read accounts of how the sensation of a severe COVID-19 infection is similar to being dragged under water, having an elephant sitting on your chest, or being dropped on top of a mountain and being asked to run a marathon.  These are vivid and jarring accounts of sensations of drowning and suffocation.  In medical speak, we call this sensation “air hunger.”

Front line doctors are also reporting an unusual discordance where there are some individuals with very low oxygen levels who are not in severe distress, while others have normal oxygen levels but are critically ill.  Clinical findings range from a pneumonia-like picture to ARDS (Acute Respiratory Distress Syndrome) or a high altitude type lung disease (aka high altitude pulmonary edema).

Regardless of the specific clinical subtype of lung disease, the one central feature is that Covid-19 provokes a severe inflammatory reaction in the lungs (aka “cytokine storm”) which impairs our ability to provide oxygen to vital tissues, and this reaction can spread to other vital organs (heart, brain, etc.) to cause more systemic disease.  Based on this mechanism, it appears reasonable that if we can improve our tolerance to any threat or stressor to the lungs and minimize the reflex outpouring of cytokines, we can lower the risk of a severe complication.  Let’s dig deeper into assessing and improving this tolerance.

Some Signs You Are Not Resilient to Low Oxygen (“Hypoxia”)

Hypoxia is the medical term we use for oxygen deficiency.  Each of us has an individual threshold to how much hypoxia we can tolerate.  As you can imagine, there is probably no greater stressor to our human physiology than the sensation of being deprived of oxygen.  Human beings can generally live for ~3 weeks without food, ~3-4 days without water, but only ~3 minutes without breathing.

Imagine having your head forced under water or someone suddenly putting a bag over your head.  This type of severe stress sends a very strong signal to our immune system that we are under threat, and can cause an outpouring of chemical messengers called cytokines.  One of the specific cellular sensors that causes an outpouring of cytokines with Covid-19 is called NLRP3, and this study shows that hypoxia turns on this specific pathway.

Studies like this also show that hypoxia is a specific trigger that causes fat cells to release inflammatory cytokines and may be one reason why obesity is such a potent risk for severe Covid-19 infections.  To learn more about cytokines, NLRP3, and the role of fat cells, read my covesity blog post.

The amount of cytokines our immune system deploys is generally proportional to the severity of the threat we encounter, with hypoxia being at or near the top of the list.

A conflict with a family member or co-worker might cause a certain amount of cytokine release, but a deprivation of oxygen, especially in someone who is not adapted to hypoxia (low oxygen) would cause a much greater release of cytokines at a potentially toxic level.  This is the dreaded “cytokine storm” of COVID-19 and other similar infections.

So the term I’m going to use to designate whether you are resilient to a low oxygen environment is “Resilience to Hypoxia” or “RH.”  I originally was thinking HR for hypoxia resilience but that would get confused with Heart Rate.  So if you have good or strong RH, that means you can handle low oxygen environments without it feeling like a major threat to your body.

Think of a Himalayan sherpa who effortlessly scales to the top of Everest, while lugging tourist cargo on his back as being someone with phenomenal RH.  On the other hand, someone with poor RH gets severely breathless with the least bit of physical stress (trying to climb a small flight of stairs) or emotional stress.

Himalayan sherpa
A sherpa with phenomenal RH

Despite being an active exerciser for most of my life, I would classify myself as traditionally having poor RH until I made some key lifestyle changes.  I’ve always been comfortable with weight lifting and interval training type exercises, but sustained cardio in the form of running or swimming had been a challenge out of proportion to the amount of training I used to do.

I would also dread the annual test in our clinic where we would be fitted for our N95 masks, an item the world has become very familiar with.  The process would involve us wearing a tight-fitting N95 mask with a giant bag over our head, while being asked to recite silly rhymes and do some light exercises.  I would always pass the test, but it just seemed to require more effort than it should.

Another example is VO2 max testing, which I’ll cover in a separate post, where you are asked to exercise at high intensity on a treadmill while wearing a tight-fitting mask.  Not meant to be a comfortable test, but seemed especially challenging for me.  Below is a picture of me during the warm-up stage of VO2 max testing.

VO2 Max testing
VO2 Max Warm-up

Now all of a sudden, a large percent of the world has access to medical or cloth masks in their home and are being asked to wear these when they are outdoors.  This is also a rough test of RH.  If it is extremely difficult for you to wear a mask for even a few minutes while doing basic house chores or shopping in a grocery store, then that might be a sign that you don’t have great RH.  I’ll discuss “masked cardio” later in this post as a way to improve RH.

So to review, some signs that you may have poor RH are below:

  • Easy Breathlessness: You become easily breathless or fatigued with minimal physical exercise/activity
  • Breath Holding Difficulty: Even short episodes of breath holding (less than 15-20 seconds) are intolerable.  Patrick McKeown, author of the Oxygen Advantage, recommends checking a BOLT (body oxygen level test) score which you can read about here, as a more specific measure of breathlessness.
  • Emotional stress easily triggers breathlessness or hyperventilation and vice versa.  Poor RH is not the root cause of anxiety or panic disorder, but can make the symptoms worse.
  • Claustrophobia:  Not all cases correlate with RH, but I’ve had some patients tell me that after learning to breathe better, they felt more comfortable in closed or crowded spaces.

Some underlying risks and conditions that can predispose you to RH are as follows:

  • Extra body weight, especially around the belly.  We covered this in detail in my covesity post.
  • Underlying lung disease:  Clearly any condition that impairs the airways or lung architecture (asthma, COPD, etc.) will impair RH.
  • Diabetes/prediabetes/insulin resistance:  These conditions are strongly linked to impaired VO2 max, a marker of aerobic function.
  • Sleep apnea:  More on this in a bit, but individuals who have difficulty breathing at night, often have difficulty during the daytime as well.

The good news is that in all of the above conditions, lifestyle changes which emphasize breathing, exercise and diet, can significantly improve or even reverse these risks.

Belly fat interestingly does not just cause a physical barrier to breathing, but also has inflammatory and metabolic impact.

This fascinating study showed that it wasn’t necessarily total weight or BMI that impaired breath holding, but more specifically belly fat measured by waist-to-hip ratio (aka WHR).  Excess belly fat is linked to metabolic disturbances like insulin resistance which can adversely impact aerobic respiration.

Sleep disordered breathing is another key area that needs to be investigated in anyone who is easily sleepy, fatigued or even breathless during the day.  My good friend Dr.Mark Burhenne wrote what I consider a groundbreaking book on sleep, called the 8-hour Sleep Paradox and his website Ask The Dentist has an excellent sleep section here.   He also did a highly informative podcast on Broken Brain which can be found here.  Also keep in mind that conditions like sleep apnea are closely connected to insulin resistance, which I mentioned is another risk for having RH.

The good news is that there are specific techniques and practices that can significantly improve your RH.  I mentioned earlier how champion endurance runners were some of the original oxygen biohackers, but surfers, swimmers, divers and others who play or compete at altitude or under water have also been using many of these techniques for years to improve their breathing and RH.

Engage Your Diaphragm

Before we talk about exercise and breathing, we must focus our attention on a critical breathing muscle, the diaphragm.  This is a parachute-shaped muscle that separates our lungs and chest wall from our abdomen.  See in the image below on the left how during inspiration (breathing in), the lungs expand outwards and the diaphragm contracts and descends straight down.  The net effect is there is an increase in the volume of our lungs which creates a vacuum and sucks air in from the outside.


diaphragm during breathing
Diaphragm during breathing

If you want to get a little more scientific, this phenomenon is supported by the Boyle’s Law equation, PV=nRT, where P is pressure and V is volume.  This equation tells us that pressure and volume are inversely proportional.  So when you “flex” or contract a well conditioned diaphragm during inhalation/inspiration, this parachute-like muscle drops down and flattens, increasing volume and thus reducing pressure in the chest cavity.  The reduced pressure is a vacuum that then sucks in a nice volume of oxygen from the outside.

On the other hand, someone who chest breathes all day and does not exercise regularly is not training their diaphragm.  A weak diaphragm exerts an insufficient contraction with inspiration that creates a weak vacuum in your chest cavity and therefore a smaller dose of oxygen is delivered to your lungs and tissues.

In fact, even regular exercisers aren’t guaranteed to be maximizing their diaphragmatic potential since many of them (including my former self) have learned to just breathe using the upper zones of their lungs.

Apart from having a weaker diaphragmatic muscle, many of us have a taut and contracted diaphragm from years of underuse and emotional tension.  Just like chronic stress can tighten up your neck and back muscles, it can also do the same to your diaphragm.  That’s why many of my patients with chronic stress have extreme difficulty with diaphragmatic breathing.  It’s like asking someone with a muscle spasm in their low back to effortlessly bend from the waist and touch their toes.

One way to remedy a taut diaphragmatic muscle is to roll your abdomen in a prone position (belly down, back up) on a soft ball or something a little squishy and practice breathing into that object while relaxing the diaphragm.  I sometimes do this before getting out of bed.  I turn over onto my stomach and breathe slowly into my mattress, my pillow, or a soft ball.  Mobility specialist, Kelly Starrett, calls this the “gut smash” and you can check out a demo video of this below.  I like to use a bit of a gentler term and call it a diaphragmatic release, but whatever works for you.


An additional benefit of living life to your full diaphragmatic potential is activation of your parasympathetic or relaxation arm of your nervous system, which counteracts our fight-or-flight stress sympathetic system.  This effect happens primarily through the stimulation of the vagus nerve, which is a primary circuit that switches on our parasympathetic system and leads to all of the beneficial effects, including lower blood pressure and heart rate, enhanced digestion, improved cognition, and an overall sense of peace and calm to name a few.

Breathing Simplified

There are a multitude of different breathing techniques and practices to choose from and most originate from the ancient Indian science of breathing known as Pranayama.  To keep things simple, the 2 major changes in breathing pattern that stimulate the vagus nerve while training the diaphragm are a combination of slowing down the breathing (aka respiratory rate) and lowering your inhalation-exhalation ratio by making your exhalation phase longer.

That’s it.  Just breathe slower and exhale a little longer than you inhale, preferably through your nose since that automatically helps you slow down your breathing by providing more resistance than breathing through your mouth.  The intervals you choose will depend on your comfort level.

Maybe start off with 4 seconds in and 8 seconds out.  We’ll call this 4-8 breathing.  Try to make your exhalation twice the length of your inhalation and if that’s too challenging, just make it 6 seconds out, so that would be 4-6.  The interval you start with should feel comfortable and relaxing, not like torture.

If you treat this like a competitive pursuit, trying to max out your breath holding time, then you will overactivate the sympathetic nervous system, which is exactly the opposite of our intent.  If this proves to be too challenging at this stage, I recommend you try the previously mentioned “gut smashing” or diaphragmatic release techniques for a few weeks to make breathing easier.

To keep track of your breathing interval, you can count in your head or use a breath counting App.  I’ve used the Universal Breathing App by Saagara for many years so am partial to that one, but you might find another one you like.  This app is not super user-friendly which is why the reviews aren’t great, so refer to my video tutorial below for help and customize your own intervals.  When you have it set up properly, it becomes an incredibly useful training tool.

Once you get comfortable with the inhalation/exhalation exercise you can add in a breath hold in between.  Dr.Andrew Weil popularized the 4-7-8 interval (inhale 4s, hold 7s, exhale 8s) but I just make it a simple 4-8-8 and with a breathing App like above, it’s easy to customize these intervals.  I’ve been doing this for a long time, so I will often do intervals of 5-10-10 or 8-16-16.

Exhaling over a period of 8, 10 or 16 seconds might seem impossible at first, but what you are really doing is teaching yourself how to precisely control the flow of exhaled air through your nose like a pressure valve.

In the beginning it will be choppy and noisy due to air turbulence, but with greater control the air stream will be smooth, controlled, and silent, and you will experience a deep sense of calm.

Do not rush to extend your exhalation intervals beyond your comfort level.  Really focus on the exhaled stream being as smooth and quiet as possible.  Once you’ve achieved that, you can then increase your exhalation time slightly.  As your breath naturally slows down and quiets, so will your mind.

Oxygen Fasting (OF) Techniques

Now I’m going to introduce you to a concept I call Oxygen Fasting or OF, similar to intermittent fasting or IF.  Just as IF improves our tolerance to caloric hunger, OF improves our tolerance to air hunger which I’ve been referring to as RH (resilience to hypoxia).  Those of us who have spent a large part of our lives, expecting to put food in our mouth every couple of hours have benefited from the effects of nutrient fasting where now we can go several hours without food.

This is not just a development of mental fortitude from fasting.  There is a specific metabolic and physiologic adaptation that allows our body to tap into its internal energy reserves rather than relying on external caloric reserves (i.e. food).

Similarly, to solve the problem of air hunger, we need to gradually train and adapt our bodies to gradually tolerate short periods of time with lesser amounts of oxygen to also trigger powerful physiological adaptations like boosting EPO levels as mentioned at the beginning of this post.  We are literally doing a more natural and legal form of blood doping when we implement some of these practices.  Below are a few OF techniques.

Like any intervention that may be a physiological stressor to the body, use common sense and pay attention to any limitations or underlying conditions you have.

For example, if you have a heart or lung condition, talk to your doctor first and if you get clearance, start very slowly with these techniques.  My other disclaimer is to not practice any challenging OF techniques if you are in a vulnerable position, such as while driving, operating heavy machinery, or lifting heavy weights without support.  Individuals who push their limits can pass out and have a serious or fatal injury.

High altitude exposure

This is the most potent (and legal!) way to get the physiologic benefits of a low oxygen environment, but it’s the least accessible for many of us.  For significant athletic benefits, you would train at a minimum of 7,000 ft elevation above sea level.  For your next getaway or for those of you who can work remotely, you might consider a retreat to a mountain cabin at elevation to take advantage of this benefit.

Nasal breathing

The practice of breathing more often through your nose is one of the simplest ways to calm your nervous system and gently introduce you to the benefits of oxygen fasting.  If it’s hard for you to remember to do this, then simply tape your mouth as you go about your work and household chores.  I’m writing this during our pandemic shelter-in period so this is a perfect opportunity to tape your mouth and entrain this habit.

Once breathing through your nose becomes effortless, start doing it during workouts.  Nasal breathe during walks, runs, interval training, yoga, etc.  If you’re not used to this at first, it will feel challenging, but then it gets easier and more natural which is a sign that you are improving your RH (resilience to hypoxia).

Be sure to read my nasal breathing post here for details which explains the science and techniques in more detail.  Nasal breathing during sleep through the practice of mouth taping was introduced to me again by my good friend and sleep expert, Dr.Mark Burhenne.  This practice can have a very beneficial effect on sleep quality.  Read about it here.

One of my favorite pranayama techniques for nasal breathing is called Nadi Shodhana or Anuloma Vilom (aka “Alternate Nostril Breathing”).  See my video tutorial on this below.  I know it looks strange, but it is profoundly beneficial and I have many patients who are high performing executives and athletes who were initially skeptical but then became believers.

Even Hillary Clinton openly expressed her enthusiasm for this practice as a stress management technique in this short video clip in her interview with Anderson Cooper.  If someone like Hillary Clinton, who is otherwise quite private and has been through her share of stress, is willing to demo an odd looking technique this publicly, you know it must have some definite benefit.

There are some real Pranayama purists who will surely critique my form with this exercise and mention how I’m not using the proper digits to close off my nostrils.  I don’t disregard the details of this technique, but I also don’t want such details to be a barrier to the practice.  Even the great Patanjali, the founder of Pranayama, didn’t emphasize these nuances and instead expressed that the primary purpose is to take in the breath, hold the breath, and then release the breath in a controlled manner.

Like I mentioned earlier with the breathing intervals, in this practice you will practice exhaling a steady and silent stream of air, but this time through a single nostril.  A 4-8-8 alternate nostril breathing interval means breathing through one nostril for 4 seconds, holding for 8 seconds, and then releasing through the other nostril for 8 seconds.  This will require more practice and concentration than doing breathing intervals through both nostrils or through your mouth, but the benefits you gain will be even greater.

I also want to briefly mention the practice of nasal humming which I cover in more detail in my nasal breathing post here.  I cited a study in that post that showed how humming increases nasal nitric oxide 15-fold which can be found here.

Apart from nitric oxide being a major blood vessel relaxer that lowers blood pressure and improves overall circulation, it also has anti-viral properties and nitric oxide is being actively explored as a potential treatment for COVID-19 since studies like this show it can inhibit coronavirus replication (SARS Co-V in this study).

I personally have been incorporating nasal humming into some of my breathing practices and also do it after being in more densely populated areas like grocery stores as I drive home with the thought that the elevation in nasal nitric oxide might reduce viral loads.  Not proven, but humming is a safe and calming practice that doesn’t have any down sides.

Breath holding

I mentioned breath holding earlier in the post.  Again, we are not talking about dangerous breath holding competitions that have resulted in severe medical complications and death.  Rather it’s the practice of brief breath holds (5-10 seconds) during light house chores or lower intensity exercise to gradually improve your RH.  You are not pushing yourself to the point of dizziness or light-headedness.  Just a mild sensation of having to catch your breath.

Once this becomes tolerable, you can extend periods or introduce them into higher intensity workouts like sprints.  There are more specific practices like Buteyko breathing, Wim Hof (combines breath holding and cold exposure), and the Oxygen advantage approach I mentioned earlier.  For my personal experience with Wim Hof and cold exposure, read this post.

Masked cardio

Using a face mask is another way to simulate a lower oxygen environment.  I’ve been using a high altitude training mask for some time and have found it to be beneficial.  It has significantly improved my aerobic endurance and overall RH which I mentioned had been a challenge for many years.  Since doing a few interviews and lectures on this topic during the COVID-19 pandemic, I find these masks are all out of stock on Amazon for now.

Cycling with High Altitude Mask
Cycling with High Altitude Mask

In the mean time, you can use your cloth or medical mask to simulate some of these effects.  It’s nice for a change to be able to walk briskly, run, or bike in my neighborhood with a mask on without my neighbors thinking I’m a weirdo, which I clearly am :).  In fact many have a clear look of “mask envy” as they admire what I call my Kylo Wren (from Star Wars) or Bane (from Dark Knight) mask.

Pay attention to how you feel initially walking or lightly exercising with a mask on.  As you do this more often, you’ll barely notice you have a mask on and will be able to gradually increase the intensity and duration of OF while wearing a mask. This is a sign that you are improving your RH.

Closing Thoughts

In our current pandemic environment, where Covid-19 seeks out and imparts the greatest damage to those of us with compromised immune systems and/or lung function, it has now become imperative that we not only become more physically active, but consciously improve the way we breathe during activity and at rest.  When we improve our RH, encountering an oxygen-constrained environment (intense exercise, high altitude, severe lung infection, etc.) no longer becomes a massive threat to our immune system, but instead allows us to defend ourselves and recover with the least amount of collateral damage.  One side benefit of the Covid-19 pandemic lockdown is that most of us are living and breathing the cleanest air we have ever encountered in our life.  I encourage you to do some of the breathing exercises we discussed outdoors so your lungs can benefit from this upgraded version of oxygen.

Remember, oxygen is the substance of life and a primary fuel for our energy-producing mitochondria, yet so many of us are consuming and utilizing inadequate amounts.  Many of us go through our days feeling anxious, breathless, and lethargic at rest and during exercise, and often a key underlying factor might be the way we breathe.  I hope this post has enlightened you and motivated you to be more breath-conscious in every aspect of your life, and I sincerely hope that breathing better will bring you more inner peace and improve other aspects of your life as it has done for me.

Additional Resources

  • My Covid survival guide has additional specifics on breathing and revised versions will add more breathing exercises.  Download the free Covid-19 survival guide here.
  • I will be adding more breathing videos to my COVIDeo Youtube series which you can find here.
  • Refer to my nasal breathing post
  • Refer to my Covid-19 exercise post here.
  • For sleep-disordered breathing issues, refer to Dr.Mark Burhenne’s site here
  • For my blog post on VO2 max, go here.
  • For a comprehensive guide on improving VO2 max from the Runner’s Blueprint site, go here.