The Oxygen Advantage: The Simple, Scientifically Proven Breathing Techniques for a Healthier, Slimmer, Faster, and Fitter You

by Patrick McKeown

  Getting his breathing right was the key to changing everything for Don. Breathing is natural and involuntary. We don’t have to remember to breathe in and out. If we did, either we would have to devote all of our time and energy to it, or we would have stopped living a long time ago. But while breathing is our most instinctive act, many factors of modern life negatively affect our breathing—and worse still, we’re highly misinformed about how our breathing affects our bodies during physical exertion. During a presentation to a group of runners who were due to compete in the Dublin city marathon the next day, I posed this question: “Who here believes that taking a large breath into the lungs during rest will increase oxygen content of the blood?” Without hesitation, 95 percent of the runners raised their hands. They were wrong, but they aren’t alone—this belief is widespread in the world of sports and fitness. But taking a large breath into the lungs during rest will not increase oxygen content. It is exactly the wrong thing to do if you seek greater endurance.

  Based on this misconception, many athletes adopt the practice of intentionally taking deep breaths during rest and training, and especially when their bodies are overtaxed. By doing so, however, they in fact limit and sometimes even diminish their performance.

  As I will explain, however, it is possible to reverse these negative influences of modern life and to condition our body to breathe healthy amounts of air during resting periods. By doing so, we ensure that the right amount of oxygen is powering our muscles, lungs, and heart. This will lead to reduced breathlessness during physical exercise, which in turn will make improved fitness more attainable. Better breathing is the gateway to a new realm of health.

  Breathe Right to Maximize Oxygenation of Your Brain, Heart, and Other Working Muscles

  Before you start the Oxygen Advantage exercises, it is important for you to have a basic understanding of the respiratory system and the role of carbon dioxide in your body. If you would like to bypass the science, you can go straight to chapter 2, but the more you know, the more you can work with your body and not against it.

  The Respiratory System

  Your respiratory system comprises the parts of your body that deliver oxygen from the atmosphere to your cells and tissues and transport the carbon dioxide produced in your tissues back into the atmosphere.

  Your respiratory system contains everything you need to adequately oxygenate your body for exercise and high-performance sports . . . so long as you allow it to function properly. When we breathe, air enters the body and flows down the windpipe (trachea), which then divides into two branches called bronchi: One branch leads to the right lung, the other to the left. Within your lungs, the bronchi further subdivide into smaller branches called bronchioles, and eventually into a multitude of small air sacs called alveoli. To visualize this complex system, imagine an upside-down tree. Your trachea is the trunk, and the bronchi form two large branches at the top of it, from which the smaller branches of the bronchioles grow. At the end of these branches are the “leaves”—the round sacs of the alveoli, which transport oxygen into the blood. It is quite a striking example of evolutionary balance and beauty that the trees around us that give off oxygen and the trees in our lungs that absorb it share a similar structure.

  The lungs contain approximately 300 million alveoli, each of which is surrounded by tiny blood vessels called capillaries. To put this immense number in context, the area of contact between your alveoli and blood capillaries is equivalent to the size of a tennis court. This large, impressively contained surface provides the potential for an extremely efficient transfer of oxygen to the blood.

  As I’ve explained, oxygen is the fuel that muscles need to work efficiently. It is, however, a common misconception that breathing in a larger volume of air increases the oxygenation of the blood. It is physiologically impossible to increase the oxygen saturation of the blood in this way, because the blood is almost always already fully saturated. It would be like pouring more water into a glass that is already filled to the brim. But what is oxygen saturation exactly, and how does it relate to properly oxygenating our muscles?

  Oxygen saturation (SpO2) is the percentage of oxygen-carrying red blood cells (hemoglobin molecules) containing oxygen within the blood. During periods of rest the standard breathing volume for a healthy person is between 4 and 6 liters of air per minute, which results in almost complete oxygen saturation of 95 to 99 percent. Because oxygen is continually diffusing from the blood into the cells, 100 percent saturation is not always feasible. An oxygen saturation of 100 percent would suggest that the bond between red blood cells and oxygen molecules is too strong, reducing the blood cells’ ability to deliver oxygen to muscles, organs, and tissues. We need the blood to release oxygen, not hold on to it. The human body actually carries a surplus of oxygen in the blood—75 percent is exhaled during rest and as much as 25 percent is exhaled during physical exercise. Increasing oxygen saturation to 100 percent has no added benefits.

  The idea of taking bigger breaths to take in more oxygen is akin to telling an individual who is already eating enough food to provide their daily caloric needs that they need to eat more. Many of my students initially have a hard time grasping this. For years they have been indoctrinated with the “benefits” of taking deep breaths by well-meaning stress counselors, yoga practitioners, physiotherapists, and sports coaches, not to mention the Western media. And it’s easy to see why this belief is perpetuated: Taking a large breath can actually feel good, even if it can actually be bad for you. Just as a cat enjoys a good stretch following a midday nap, taking a big breath into the lungs stretches the upper part of the body, allowing a feeling of relaxation to follow. But this leads many to believe that with breathing, bigger is better.

  Regulation of Breathing

  There are two main aspects to the way you breathe: the rate or number of breaths you take in the space of 1 minute and the volume or amount of air drawn into your lungs with each breath. Although the two are separate, one generally influences the other.

  The volume of each breath of air we inhale and exhale is measured in liters, and measurements are usually taken over 1 minute. In conventional medicine the accepted number of breaths a healthy person takes during that minute is 10 to 12, with each breath drawing in a volume of 500 milliliters of air, for a total volume of 5 to 6 liters. To visualize this amount of air, imagine how much air would be contained in about three empty 2-liter soft drink bottles. If a person is breathing at a higher rate—at 20 breaths per minute, for example—then the volume will also be higher. But overbreathing doesn’t just come from an elevated rate. A lower rate can have the same effect if the individual is taking in too much air with each breath; 10 large breaths of 1,000 milliliters would also be evidence of overbreathing. In the next chapter, you will be able to measure your own relative breathing volume using a breath-hold test called the Body Oxygen Level Test, or BOLT.

  So how do we ensure that we breathe correctly so as to make optimal use of our amazing respiratory system? As odd as this may seem, it’s not oxygen that exerts the primary influence on your breathing efficiency, but carbon dioxide.

  The rate and volume of breathing is determined by receptors in the brain that work in a way similar to a thermostat regulating the heating system in a home. However, instead of monitoring fluctuations in temperature, these receptors monitor the concentration of carbon dioxide and oxygen in your blood, along with the acidity or pH level. When levels of carbon dioxide increase above a certain amount, these sensitive receptors stimulate breathing in order to get rid of the excess gas. In other words, the primary stimulus to breathe is to eliminate excess carbon dioxide from the body.

  Carbon dioxide is an end product of the natural process of breaking down the fats and carbohydrates we eat. CO2 is returned from the tissues and cells to the lungs via blood vessels, and any excess is exhaled. Crucially, however, part of your body’s quotient of carbon dioxide is retained when you exhale. Correct breathing both relies on and results in the right
amount of carbon dioxide being retained in your lungs. Understanding this is just as important for serious athletes as it is for anyone interested in basic fitness or in weight management.

  Think of it this way: CO2 is the doorway that lets oxygen reach our muscles. If the door is only partially open, only some of the oxygen at our disposal passes through, and we find ourselves gasping during exercise, often with our limbs cramping. If, on the other hand, the door is wide open, oxygen flows through the doorway and we can sustain physical activity longer and at a higher intensity. But to understand how our breathing works we must dig a bit deeper into the crucial role carbon dioxide plays in making it as efficient as possible.

  Chronic hyperventilation or overbreathing simply means the habit of breathing a volume of air greater than that which your body requires. It does not necessarily manifest as dramatic symptoms, such as the panting a person might experience during a panic attack. When we breathe in excess of what we require, too much carbon dioxide is exhaled from the lungs and, hence, is removed from the blood. It forces that door to a more closed position, making it harder for oxygen to pass through. Breathing too much for short periods of time is not a significant problem, as no permanent change in the body occurs. However, when we breathe too much over an extended period of days to weeks, a biochemical change takes place inside us that results in an increased sensitivity or lower tolerance to carbon dioxide. With this lower set point, breathing volume remains above normal as the receptors in the brain continuously stimulate breathing in order to get rid of carbon dioxide that is perceived to be in excess of the receptor’s programmed limits. The result is the habit of chronic overbreathing or chronic hyperventilation, with all its negative manifestations. In other words, certain circumstances can train our body to breathe in such a way that goes against its own interests. To counteract these bad habits, you must retrain yourself to breathe better.

  I often ask my groups of students this question: “Who feels that they are more tired than they should be?” Usually about 80 percent raise their hands. My job is to help them understand why. With the aid of a pulse oximeter, I have measured the oxygen saturation of thousands of people, and the vast majority display normal blood oxygen saturations of between 95 and 99 percent.* Why would this be? Their blood oxygen saturations are normal, yet they constantly feel tired. The problem is not a lack of oxygen in the blood, but that not enough oxygen is being released from the blood to tissues and organs, including the brain, resulting in feelings of lethargy and exhaustion. This happens because too much carbon dioxide has been expelled from the body. As we shall see further on, habitual overbreathing influences the release of oxygen from red blood cells, the consequences of which can affect day-to-day well-being as well as performance during exercise. This ties back to the Bohr Effect, which I touched on in the introduction and will expand on in a few pages.

  One’s breathing volume can be two or three times the required amount without it being overtly noticeable. Once the pattern of overbreathing is established, it is often maintained by an occasional deep breath or sigh. When such a habit becomes ingrained both mentally and physically, you will breathe in excess of what is required every minute, every hour, and every day. This subtle alteration to your body’s natural functioning can hinder you greatly. And it doesn’t just happen while we’re conscious; many people sleep with their mouth open, and whether they realize it or not, this drags down their physical and mental energy.

  So why is it that the benefits of light breathing are relatively unknown? It is difficult to know the exact answer, although a number of points are worth bearing in mind. The first is that air is weightless and therefore difficult to measure, and breathing can change quickly and effortlessly during the measuring process. The second is that doctors learn how oxygen is released from the red blood cells early on in their studies—the Bohr Effect is described in most basic medical school physiology textbooks—so it is possible that this information is simply forgotten by the time of graduation. Another reason may be that overbreathing affects each person individually, resulting in a wide variety of problems that may not necessarily appear to be connected, from cardiovascular, respiratory, and gastrointestinal issues to general exhaustion. To add even more confusion, not everyone who overbreathes will develop obvious symptoms, as the effects of hyperventilation depend on genetic predisposition.

  Finally, given the lack of awareness of the relationship between breathing volume and health, so many chronic overbreathers have learned to tolerate the stunted levels of energy and fitness incorrect breathing leaves them with in day-to-day life. But shaking ourselves out of this complacent attitude toward our breath and putting it at the center of our health often produces more dramatic changes than any diet.

  So how can we regulate the amount of air we breathe in order to optimize our fitness and athletic performance? As you know by now, the vital ingredient is carbon dioxide.

  Carbon Dioxide: Not Just a Waste of Gas

  The concentration of carbon dioxide in the earth’s atmosphere is very low, which means that we don’t carry it into our lungs when we breathe. Instead we produce it in tissue cells during the process of converting food and oxygen into energy. Maintaining a correct breathing volume ensures that the ideal amount of carbon dioxide remains in the lungs, blood, tissues, and cells.

  Carbon dioxide performs a number of vital functions in the human body, including:

  • Offloading of oxygen from the blood to be used by the cells.

  • The dilation of the smooth muscle in the walls of the airways and blood vessels

  • The regulation of blood pH.

  Delivery of Oxygen from the Blood to the Muscles and Organs

  Hemoglobin is a protein found in the blood, and one of its functions is to carry oxygen from the lungs to the tissues and cells. A fundamental element of the Oxygen Advantage technique is to understand the Bohr Effect—the way in which oxygen is released from hemoglobin and delivered to the muscles and organs. This process forms the core of unlocking your body’s true fitness potential, allowing you to raise your game and achieve the results you really want.

  The Bohr Effect was discovered in 1904 by the Danish physiologist Christian Bohr (father of Niels Bohr, the Nobel Prize–winning physicist—and footballer). In the words of Christian Bohr, “The carbon dioxide pressure of the blood is to be regarded as an important factor in the inner respiratory metabolism. If one uses carbon dioxide in appropriate amounts, the oxygen that was taken up can be used more effectively throughout the body.”

  The crucial point to remember is that hemoglobin releases oxygen when in the presence of carbon dioxide. When we overbreathe, too much carbon dioxide is washed from the lungs, blood, tissues, and cells. This condition is called hypocapnia, causing the hemoglobin to hold on to oxygen, resulting in reduced oxygen release and therefore reduced oxygen delivery to tissues and organs. With less oxygen delivered to the muscles, they cannot work as effectively as we might like them to. As counterintuitive as it may seem, the urge to take bigger, deeper breaths when we hit the wall during exercise does not provide the muscles with more oxygen but effectively reduces oxygenation even further. In contrast, when breathing volume remains nearer to correct levels, the pressure of carbon dioxide in the blood is higher, loosening the bond between hemoglobin and oxygen and facilitating the delivery of oxygen to the muscles and organs. John West, author of Respiratory Physiology, tells us that “an exercising muscle is hot and generates carbon dioxide, and it benefits from increased unloading of O2 [oxygen] from its capillaries.” The better we can fuel our muscles with oxygen during activity, the longer and harder they can work. In light of the Bohr Effect, overbreathing limits the release of oxygen from the blood, and in turn affects how well our muscles are able to work.

  Dilation and Constriction of Airways and Blood Vessels

  Breathing too much can also cause reduced blood flow. For the vast majority of people, 2 minutes of heavy breathing is enough to reduce blood circulation
throughout the body, including the brain, which can cause a feeling of dizziness and light-headedness. In general, blood flow to the brain reduces proportionately to each reduction in carbon dioxide. A study by Dr. Daniel M. Gibbs, which was published in the American Journal of Psychiatry to assess arterial constriction induced by excessive breathing, found that the diameter of blood vessels reduced in some individuals by as much as 50 percent. Based on the formula πr2, which measures the area of a circle, blood flow decreases by a factor of four. This shows you how radically overbreathing can affect your blood flow.

  Most people will have experienced constriction of blood flow to the brain resulting from overbreathing. It doesn’t take very long to feel the onset of dizziness from taking a few big breaths in and out through the mouth. Similarly, many individuals who sleep with their mouths open may find it difficult to get going in the morning. However long they sleep, they are still tired and groggy for the first few hours after waking. It is well documented that habitual mouth breathing during waking and sleeping hours results in fatigue, poor concentration, reduced productivity, and a bad mood. Hardly an ideal recipe for quality living or a productive exercise program.

  The same can also be true of individuals whose occupation involves considerable talking, such as schoolteachers or salespeople. People in these professions are often all too aware of how tired they feel after a day of work, but the exhaustion that follows endless business meetings is not necessarily due to mental or physical effort—more likely it is a result of the effects of elevated breathing levels during excessive talking. It is normal for breathing to increase during physical exercise as the body demands more oxygen to convert food into energy. However, in the case of talking, breathing increases without an actual need for more oxygen, causing a disturbance to blood gases and reducing blood flow.