When we go for a run or we are dedicated to lifting weights in the gym, we usually worry regarding what clothing and footwear to wear, how to warm up the muscles or even how many beats we must reach for the training to be effective.
However, we tend to ignore the effect of breathing on physical performance.
We are all aware that the mission of the respiratory system is gas exchange. That is, it is responsible for both obtaining oxygen (O₂) from the outside to produce energy and eliminating the waste product, carbon dioxide (CO₂). Therefore, it allows us to live.
But, let’s break down the process more technically. ANDThe air enters through the nose, circulating through the airways to the pulmonary alveoli.where gas exchange takes place.
From there, oxygen passes into the blood to be transported to all cells. At the same time, the CO₂ they produce is transported to the lungs for elimination.
This is how it works under normal conditions, but what regarding when we exercise? muscles work much more intenselyconsuming more oxygen and producing more CO₂.
The frequency goes from 15 breaths per minute at rest to 40-60 per minute in full activity. As a consequence, the amount of air that enters increases, which goes from 12 to 100 liters.
During this extra exchange of gases, our respiratory system is in charge of keeping the acidity of the blood constant, which is measured by the Ph, through the expulsion of CO₂.
Another detail to take into account is that oxygen reaches the muscles through the blood thanks to the red blood cells (the “carriers” that carry it from the lungs), specifically from the hand of a macromolecule called hemoglobin.
Well, for an oxygen molecule to be taken up by hemoglobin in red blood cells passing through the lung, another CO₂ is needed that allows the hemoglobin to release oxygen at the destination site.
Ultimately, it is the amount of CO₂ in the body which conditions the correct supply of O₂ to the muscles.
Now that we know regarding hemoglobin, we cannot forget regarding a key property: the Bohr effect. It refers to the fact that when we activate our body, there is an increase in CO₂ and, therefore, in hydrogen ions, causing the pH to become acidic.
This causes the hemoglobin absorb oxygen with greater affinityachieving a greater contribution of O₂ in those areas of our body where more CO₂ is released.
Therefore, exercising, our body generates more CO₂, and the Bohr effect kicks in. In short, the Bohr effect allows our friend hemoglobin to release more oxygen the higher our activity.
For this reason, when it comes to breathing, we should not only be guided by intuition. Although one might think that for physical exercise it is better to breathe through the mouth, if we expel the air through the mouth we run the risk of losing too much CO₂.
In fact, when we get out of breath while exercising, it is not because our muscles get tired, but because they are not receiving oxygen well because they do not have enough CO₂ to exchange.
After reviewing the scientific works of recent years, a recent publication concluded that it is not so clear that it is good use the mouth to breathe during sports.
Furthermore, the evidence suggests that theexclusively nasal breathing is feasible for most people at moderate levels of aerobic exercise without specific adaptation, and that this breathing approach can also be achieved during intense levels of aerobic exercise.
Another reason to breathe through the nose is nitric oxide (NO), a vasodilator that is produced in the epithelial cells of the nasal cavity as air passes through.
It is known that nitric oxide, among other functions, participates in chronic inflammation processes and in the modulation of lung function. AND it is also a potent vasodilator that diffuses very quicklyachieving a greater opening of the airways.
This is very important for people who suffer from exercise-induced asthma. In fact, it was shown that this pathology greatly improves by breathing through the nose.
We have explained that nasal breathing helps athletes to obtain better performance, especially when the effort is sustained and moderate.
Although breathing through the nose takes less air into the lungs, the air supply is sufficient to maintain activity and does not seem to cause problems.
However, things change when more demanding conditions are reached. With maximum effort, athletes automatically switch their breath to the mouth.
Interestingly, scientists have shown that this change occurs earlier in women than in men by increasing the intensity of the exercise, and they explain it because women tend to have smaller noses.
In the most demanding and fastest race, the 100-meter dash, athletes breathe through their nose and mouth simultaneously. Of course, in just 10 seconds. It is enough to observe Carl Lewis or Usain Bolt in the Olympic finals to verify it.
There are two exceptions to the cases we have considered above: yoga and pilates. In these two modalities of physical exercise, breathing is a very important part, and its technique is the first thing that is learned.
This is always of the nose-mouth type (that is, it is inhaled through the nose and exhaled through the mouth). This is especially important in the case of Pilates, with a very determined execution that involves (and shapes) the muscles that surround the rib cage, exercising them both when breathing in and out.
Using a technique called EMG or “electromyography” to measure muscle activation in real time, the beneficial effects of Pilates breathing were demonstrated.
Specifically, in elderly people there are studies that show the great benefit of Pilates breathing to encourage muscle activation when exercising.
And the benefits go further: the alignment of the spine is also improved and loss of balance is avoided. There is, therefore, no single answer to the question regarding how we should breathe during physical exercise: it depends on the type of activity.
What we are convinced of is that the next time you listen to the explanations of your instructor or coach on how to breathe, you will not think: “what a heaviness” or “what else does it matter”. Because a good breathing routine will influence your performance.
*By Matilde Cañelles López, Mercedes Jiménez Sarmiento and Nuria Eugenia Campillo
