Featuring Improved Respiration (IR)

Anxiety, stress, disruption of sleep…The harmful effects on our body are not inevitable. How we breathe transforms our experience. When we choose to improve the way we breathe, we create our own bilogical power. In 2020 something happened. An invisible enemy, is threatening our vital necessity to breathe. We realized we have to fight back, together as a team. A plan to hook our breath was put into action,. The Warrior Breathing Training Program was launched, evidence based of five different field of expertise in breathing; Triathlon, Freediving, Yoga, science and military special operations forces. At any age everyday of our life we can improve the way we breathe.

«Know Thyself»- One of the Delphic maxims

When I first started my hatha yoga training in 2017 to improve my performance as a freediver I wanted to become better at breathing. I have trained different styles of yoga, namely: Bikram yoga, Ashtanga yoga, and more recently Gravity yoga.

After taking several classes, I realized that all of the yoga teachers always talk about breathing and its positive effects on the body. Every instructor stresses the importance of breathing deeply and slowly. However, the majority don’t explain what the meaning of slow breathing or deep breathing is.

I wanted to find the science behind deep and slow breathing and the reason why this type of breathing is so beneficial for health. I quickly found out it is a question that involves a great deal of technical aspects.

Considering my interest in becoming better in the art of breathing, I studied the science of respiration, and found wonderful, basic, and simple information, and realized most people don’t practice it. Most of the yoga teachers, sports coaches, respiratory therapists, and mindfulness practitioners teach breathing the wrong way. They promote practices that decrease oxygen. The reason is they have paradoxical thinking about the oxygen being good and the carbon dioxide being bad.

In this publication you will find out the explanation of this paradox., In this specific occasion, I will outline the basic respiration concepts, the history of breathing, and will analyze the different type of contemporary breathing techniques.

Just because breathing is a simple act, it does not mean it is easy or unsophisticated. We will learn about the physiological effects of improved respiration, as part of a breathing program, as well as the attributes, objectives, and principles of improved respiration. The goal is to submerge in the sophisticated art of breathing in the simplest way possible.

The Science of Breathing

Breathing is the basic biological function of taking in air, absorbing oxygen, and then exhaling carbon dioxide. Breathing is mostly taught incorrectly. Most of the yoga teachers tend to vilify the carbon dioxide using expressions like “inhale the pure life-giving oxygen and exhale the dirty toxic carbon dioxide”. This concept is a huge mistake. We need both of them in a balanced way as we will understand in this publication.

The Basic Concept of Respiration

Respiration is the process in which food is broken down in the cells with the help of oxygen to release energy, breathing is part of respiration. There are three types of respiration, external, internal, and cellular. External respiration is where gaseous exchange occurs in the nasal level, the oxygen from the surrounding air is brought inside the nasal cavity and the carbon dioxide is given out.

Internal respiration, as the name suggests occurs inside the body, is an exchange of gases in the lungs, blood, and cells. The oxygen from the air reaches the lungs, it´s transported to the blood, similarly, carbon dioxide from the blood is given out to the lungs which travel later to the nasal area. The oxygen then travels throughout the body and is delivered to the cells and the carbon dioxide is taken away. Cellular respiration is the process in which oxygen is used to breakdown the molecules by the cells.

The respiratory system involves the nose (or mouth), the pharynx, the trachea, the bronchi, the lungs, the bronchioles, and the alveoli. A natural healthy breath is inhaling and exhaling through the nose. The exercises of the WBTP, are focused on nose breathing with a couple of exceptions.

Muscles of Respiration

The muscles of the respiratory system are the diaphragm, the intercostal muscles, and the supporting muscles for breathing, the neck, the chest, the shoulders, and the back.

The diaphragm is the most important one; it can get stronger, it can get longer, it can get weak, it can get spasms. The diaphragm contracts down to create a vacuum for the air to come in during the inhalation and relaxes up for exhalation. To support effectively the respiratory process, the diaphragm needs to be strong and flexible. The bad news is that most people have a weak and tight diaphragm, the good thing is that we can train this muscle, we can strengthen and build it, in fact, this is one of the main objectives of the WBTP.

The lungs

Each of the pairs of  organs situated within the rib cage. The right lung has three lobes and is bigger, the left lung is smaller to make room for the heart. Men have an average lung capacity of six liters, and the women’s average capacity is 4,2 liters. The lung capacity can increase through exercise.

The Lung Volumes

	ml
Tidal volume	350-500	The amount of air breathed in or out during a normal average breathing cycle.
Inspiratory reserve volume	2000-3000	The maximum volume of air that can be inhaled in addition to the tidal volume.
Expiratory reserve volume	1000-1500	The amount of additional air that can be exhaled after a normal exhalation.
Residual volume	1000	The amount of air that remains in the respiratory system after a forced exhalation.
Vital capacity	3500-5000	The sum of tidal volume, inspiratory and expiratory reserve volumes.
Total lung capacity	6000	The sum of vital capacity and residual capacity.

Rhythm: The number of breaths per minute.

Ratio: The duration of each inhale, exhale and breath hold in between or at the end, depending on the type of breathing technique.

Dry Air Inhaled

78 % nitrogen

21 % oxygen

0,93% argon

0,04% CO2

Moist Air Inhaled

74,4 % nitrogen

13,6 % – 16 % oxygen

4,0 % – 5,3 % CO2

5,0 % – 6,3 % vapor

Role of Oxygen

Oxygen is the fuel that our body needs to work efficiently. It is essential for every cell in the body. The paradoxical thinking about oxygen being good leads to a common misconception that breathing deep is equivalent to breathing larger volumes of air to increase the oxygenation of the blood. This is not possible.

Oxygen saturation is the percentage of oxygen-carrying red blood cells containing oxygen within the blood. The average lung capacity of a person is 6000 ml. Healthy individual breathing at a natural rhythm has an oxygen saturation between 95 % and 99%. This percentage of saturation can´t increase because oxygen is diffusing permanently from the blood into the cells.

We can assess the effectiveness of oxygenation by knowing the Vo2 max, which is the maximum volume of oxygen that the human body consumes in one minute during exhausting exercise. The WBTP focuses on increasing the Vo2 max of the average person.

Role of Carbon Dioxide (CO2)

Here is the reality of paradoxical thinking concerning carbon dioxide being a “toxic substance” the body exhales to get rid of, the CO2 is a vital gas, necessary to offload oxygen from the blood to the cells. One essential function of CO2 is the dilation of the breathing passageways.  High tolerance of the body to CO2 increases the oxygen release. Therefore, increasing CO2 tolerance is a crucial objective of WBTP.

Breathing is an automatic process we are not aware of. The problem is most people are not conscious of how they breathe. They don’t breathe correctly, they over-breathe.  In other words, they breathe more air than they need without knowing it. The solution for this over breathing issue is to make conscious changes in breathing habits. The result, being able to breathe more efficiently, strengthen both body and mind. Efficient breathing habits may contribute to more positive energy in everyday life. 

One advantage of gaining consciousness of breathing is a better use of carbon dioxide. CO2 is a by-product of the metabolism of carbohydrates, fats, and amino acids, in a process known as cellular respiration. The majority of people think CO2 is just a waste gas. On the contrary, it is a key element, which allows the release of oxygen from the red cells to be metabolized by the body. This is the BOHR effect ** (Discovered by Physiologist Christian 1855-1911). 

Having improved respiration increases the amount of carbon dioxide inside the body, then more oxygen will be delivered to the muscles and organs, including the heart and brain, and thus heighten our physical capacity.  As explained in the book, “The Power of Breathing Techniques”, by Lutz Schneider, breathing is determined by receptors in the brain that monitor the concentration of carbon dioxide and oxygen in the blood, along with the acidity or PH level. 

When levels of carbon dioxide increase above a certain amount, these sensitive receptors stimulate breathing to get rid of the excess gas. In other words, the primary stimulus to breathe is to eliminate excess carbon dioxide from the body. 

In addition to the above, a high concentration of CO2 in the blood produces a contraction of the spleen, increasing the release of red blood cells (stored in the spleen) and therefore the oxygenation of the blood. 

It’s important to train breathing exercises that generate the habit of conscious breathing, especially breath-hold exercises because the body adapts to tolerate a higher concentration of CO2 levels. This is the mechanism that allows the CO2 to spread its protective wings over the oxygen supply to the body (as the quote at the beginning of this article). Higher tolerance to CO2 strengthens the protection granted by the CO2 to the body since there will be  better oxygenation in all organs of the body.

Consequently, the improved respiration virtuous loop is formed; breath hold training, great CO2 tolerance, better oxygenation (high VO2 MAX), peak performance in endurance sports.   

With this information, we can understand that both oxygen and carbon dioxide are essential to improve our respiration. They work together to make breathing more efficient. The goal of the WBTP is to maintain a balance between these two gasses, its exchange is essential for health.

The Concept of Improved Respiration

In the series of Breathe Like a Warrior, we identify improved respiration (IR) with the physiological action of inhaling and exhaling consciously with the greatest possible effectiveness to reach the full potential of the respiratory act. This is, to breathe well and with a high-quality technique. Developing IR means breathing calmly all the time through the nose and making the movements when inhaling and exhaling so subtly that they are imperceptible.

The warrior Breathing Training Program (WBTP) is the vehicle to achieve IR as safety training, with science-based techniques. It is a moderate program, simple, appropriate, and accessible for the average person regardless of age, it is effective for all people.

The WBTP is now available on Amazon Kindle

Safe and Simple

One of the goals of the WBTP is to find simplicity in the practice of pranayama. It is a simple way to practice exercises that anyone can use to activate the autonomic nervous system and induce relaxation. The workouts proposed in the WBTP have specific execution instructions that follow safety ranges of performance. It is important to never force the breath. Always practice breath-hold type exercises with moderation. In water, never train breath holding exercises alone. Never practice any type of breathing workout while operating vehicles.

Scientific

WBTP is based on four principles and 5 objectives that aim to improve the health and wellness of the practitioner safely through scientific-based workouts.

Autonomic Nervous System

The principles and objectives of the WBTP impact the nervous system, either activating the sympathetic nervous system, stimulating the parasympathetic nervous system, or balancing the autonomic nervous system.

In today’s world, emerging events are permanent and cause two effects: generate stress and alter emotional control, which can negatively affect decision-making. Neutralizing the toxic effects of prolonged stress is vital, and stabilizing emotional control is also critical to maintaining mental clarity in the decision-making process in crisis situations. The solution is simple and similar to the advice of our grandmothers; «Count to ten and breathe.» But the reality is that the benefits of breathing are not activated with a magic count to 10 formula and voila!

It is necessary to train systematically and progressively to achieve IR and thus, be able to positively influence the control of emotions and decision-making. The reason, as we will see below, is because through pragmatic breathing practices the mind can be connected with the part of the nervous system that works without our will, and this, in turn, can regulate aspects that help positive management of stress and emotions.

Parasympathetic Branch

The part of the nervous system that works without direct control of the mind is the autonomic nervous system (ANS), which includes the parasympathetic nervous system (PNS) which in turn has a relaxing function for the body. It reduces heart rate and blood pressure and also promotes digestion and absorption of nutrients. The organism enters into what psychologists have baptized the «rest and digest» mode.

It is particularly the PNS, which fortunately can be activated with breathing practices, and especially with those that include apnea (holding the breath). In his book, Breatheology, The Art of Conscious Breathing, Stig Avall Severinsen claims that holding the breath for a short time and then exhaling slowly stimulates the vagus nerve and gives the body and mind a sense of peace. The vagus nerve connects from the brain to various parts of the body including the lungs, heart, and stomach.

Likewise, in the Manual of Freediving, Umberto Pelizzari, refers to an interesting study published in 2009 by Professor Angelo Geminiani, from the Department of Psychological Science at the University of Pisa, based on research carried out during a convention of freedivers in Lignano Sabbiadoro. This publication demonstrates that during a prolonged and controlled exhalation there is a significant change in brain activity that replaces the moving beta waves with the more pleasant alpha waves. This induces a general reduction of the metabolism, starting with a decrease in heart rate, without in any way influencing the state of consciousness.

To take advantage of the practical effects of improved breathing, the fourth principle of the WBTP considers the science-based information described in the previous paragraphs to induce the relaxation response of the organism.  

Sympathetic Branch

When a person is facing a possible dangerous or threatening situation, the sympathetic branch of the nervous system (SNS) activates the fight or flight response and a whole chain of events happens. The digestion stops, the blood goes to the muscles and lungs, as much as twelve times more, adrenaline, cortisol, and noradrenaline go up and heart rate increases.

The body has natural cycles, both branches are necessary for the organism. Finding a good balance between the two branches of the ANS is crucial to maintain  good quality health. People need to recognize the threatening situations that trigger the fight or flight response of the SNS.

Heart Rate Variability (HRV)

The ANS is affected by the way we breathe, and the way we breathe affects the ANS. HRV is simply a measure of the variation in time between each heartbeat. HRV measures the changes of the heart, beat to beat. This variation is controlled by the ANS. HRV reflects the ANS tone, it gives a real precise test of how the ANS is performing.

People who have  high HRV may have greater cardiovascular fitness and be more resilient to stress. A good nervous system is an agile one. A healthy heart has a lot of variabilities. A healthy person (with a healthy heart and ANS) has a high HRV when inhaling the heart rate goes up, when exhaling the heart rate goes down, this is affected by the tone of the ANS.

Vagus Nerve

Is the tenth cranial nerve, is the longest of the ANS. Is largely responsible for the parasympathetic response. The vagus nerve controls the heart, lungs, and digestive tract.

The vagus nerve passes through the opening of the diaphragm, it is stimulated by diaphragmatic breathing, also by humming and singing. IR promotes vagal tone. Having a high vagal tone means having an ANS responsive to the environment, and can adapt. The vagal tone is a clear indication of the condition of the ANS.

Other Physiological Aspects

Also, to the importance of the exchange of CO2 and oxygen in the respiration cycle, another gas is essential in this vital process, the nitric oxide or the miracle molecule.

Nitric oxide (NO), also called the molecule of life, is an activating gas of the cardiovascular system, which has the property of vasodilation. Nasal passages produce NO, in the paranasal sinuses, the gas is inhaled into the lungs and absorbed in the blood for dilation of arteries and arterioles. NO is a strong vasodilator and bronchodilator. This makes NO a powerful factor for improving blood flow.

The first principle of the WBTP, total nasal breathing, targets to build a natural NO booster capability with the respiratory system.

A healthy individual always breathes through the nose. The nose does temperature control, humidifies, and purifies the air. Also, it adds friction and control to the breath that increases breath efficiency. It triggers neuroreceptors in the nostrils and sinuses that signal safety. Also, nose breathing has a big impact on the quality and quantity of sleep. Any sleep doctor will immediately look to the breath as one of the possible causes of disruption of sleep.

 Some possible problems of breathing dysfunctions during sleep are apnea, insomnia, snoring, obstructive breathing, sinusitis. All these conditions could have negative implications on your health. People who don’t sleep well usually have elevated cortisol levels. Poor sleeping is correlated with negative mental and emotional conditions like anxiety and depression disorder.

Endocrine system

The way we breathe has a remarkable impact on several body systems, including the endocrine system. IR balances the production of some vital hormones like erythropoietin (EPO), adrenaline, noradrenaline, and cortisol.

EPO: Erythropoietin, also known as EPO, is a hormone secreted by the kidneys in response to reduced oxygen levels in the blood. EPO is responsible for maturing red blood cells in the bone marrow to release them into the bloodstream. When the concentration of the red blood cells carrying oxygen from the lungs to the muscles is high, the aerobic capacity of an individual grows.

Breath-hold exercises included in the WBTP increase the EPO production naturally, and thus improving oxygenation to the muscles

Adrenaline is a hormone secreted by the adrenal glands that increase rates of blood circulation, breathing, and carbohydrate metabolism and prepare muscles for exertion.

 Noradrenaline is released by the adrenal medulla and by the sympathetic nerves and functions as a neurotransmitter. The general function of noradrenaline is to mobilize the brain and body for action.

Cortisol is a hormone involved in the regulation of metabolism in the cells and helps to regulate stress within the body.

Zone 3 breathing workouts stimulate the secretion of adrenaline, noradrenaline, and cortisol to prepare the body to enter in a fight or flight response to perform better in physical activity.

The Diving Response

Also referred to as the diving reflex, (DR) is a sequence of physiological adjustments that occur in all mammals including humans that involve the nervous, cardiovascular, and respiratory system acting in a manner that promotes oxygen conservation through decreased heart rate and cardiac output and the diversion of blood flow to vital organs such as the brain and heart during underwater submersion.

Aspects of the DR were first described by Edmund Goodwynd in 1786, but it was until a1870 publication by Paul Bert for the physiologic adaptations that it would be recognized.

The exercises involving breath-holding generate the DR to be able to modify the metabolism due to the reduced storage of oxygen. The body needs to find new energy sources as an alternative.

The unique aspect of the DR is it involves the simultaneous effects of both sympathetic and parasympathetic nerve activation on the cardiovascular system.

The DR is the most powerful autonomic reflex known. The mammalian diving response is a remarkable behavior that overrides basic homeostatic reflexes. It is most studied in large aquatic mammals but is seen in all vertebrates. Pelagic mammals have developed several physiological adaptations to conserve intrinsic oxygen stores, but the apnea, bradycardia, and vasoconstriction is shared with those terrestrial and is neurally mediated. The adaptations of aquatic mammals are reviewed here as well as the neural control of cardiorespiratory physiology during diving in rodents. The DR is an amalgam of three independent reflexes inducing physiological changes that counter normal homeostatic control. There is a hypothesis presented in the study “The Diving Mammalian Response” by Michael Panneton which says the purpose of the DR is to conserve intrinsic oxygen stores, no matter what the species.

The DR is based on respiration where the animals are rendered apneic by underwater submersion. The source of the organisms’ oxygen–a mammal cannot breathe underwater or it will drown–is lost underwater. Thus, to survive, underwater mammals must rely on intrinsic oxygen stores bound mostly in the blood to hemoglobin and in muscle to myoglobin.

The conservative use of intrinsic oxygen stores maintains aerobic metabolism; when these stores are depleted, the diving animal has reached its aerobic dive limit, a metabolic threshold where diving duration goes beyond intrinsic oxygen stores and is marked by lactate concentration in the blood increasing above resting levels. The cardiovascular system helps remedy this problem of anoxia.

A controlled reflex of onset bradycardia, a parasympathetic response, is foremost and reduces cardiac output dramatically, which by itself would induce a precipitous drop in arterial blood pressure. Thus, the sympathetic nervous system counteracts the ensuing pressure drop, and massive peripheral vasoconstriction commences redistributing circulating blood by reducing blood flow in cutaneous, muscular, and splanchnic circulations, but a maintained or augmented flow to the central nervous system and heart. These reflex behaviors collectively may be the ultimate weapon organisms possess to maintain life during asphyxia.

An interesting research by Godek Freeman shows that the DR can be used as a quick, simple, and non-invasive clinical maneuver that is effective in eliciting increased vagal tone which induces bradycardia and results in the termination of cardiac disorders.

WBTP Methodology – a SOF Training Approach

The WBTP is a training plan, which preserves the principles of SOF training with a methodological approach focused on specific objectives, defined standards, and a desired end state (effects to be achieved) through 5 categorized breathing zones.

Each breathing workout of the WBTP includes a methodology to be followed that includes:

1. Description of the workout
2. Training objective
3. Execution, specifying the rhythm and the frequency
4. Effects of the practice
5. The breathing zone of the workout

Breathing Zones and Characteristics

Depending on the rhythm and the purpose, each breathing workout is categorized in zones (1 to 5).

Zone 1 Slow Breathing

     1. Rhythm: Less than three breaths per minute.

     2. 1:2 ratio (inhale 4 / exhale 8 is the average standard).

     3. Diaphragmatic breathing.

     4. Nose only, with the exceptions of some exercises that include nose to mouth.

Zone 2 Balanced Breathing

1. Rhythm: It´s half the natural rhythm but keeps the volume up.
2. The breathing is slow but deep.
3. The volume is approximately 4 to 6 liters per minute.
4. Nose only breathing.
5. Is important to focus in diaphragmatic breathing.

Most of the training workouts of the WBTP are done in zone 2. The diaphragm contracts down in the inhale and relaxes in the exhale. During diaphragmatic breathing the muscle of the diaphragm is innervated by the vagus nerve, so it is toned and stimulated.

Zone 2 workouts emphasize rest and digest response toning the nervous system. This type of practices can be done at any time of the day, always good to practice before meals and before bedtime.

Zone 3 Fast Breathing

1. Rhythm: 30 or more breaths per minute.
2. Reduces CO2.
3. Raises blood PH slightly more alkaline.
4. Constricts blood vessels and breathing passageways.
5. A slight increase in blood 02, adrenaline, noradrenaline, and cortisol.
6. Stressful type of breathing.

Zone 3 breathing workouts are recommended to do in the morning, or before any physical activity. These workouts activate the sympathetic nervous system.

Zone 4 Strengthening Workouts for the Breathing Muscles

The muscles of the respiratory system can get stronger with specific training.

Zone 4 breathing workouts’ primary focus is to strengthen the diaphragm, the intercostal muscles, and the breathing supporting muscles.

Zone 5 Breathing Fitness Test (BFT)

Measuring results is fundamental to know the training is working fine. The WBTP has different BFTs scheduled periodically to evaluate the efficacy of the program. BFT exercises are categorized in zone 5.

WBTP is based on 4 principles:

1. Total nasal breathing when inhaling and exhaling, to enhance the natural production of NO. It should be noted there are a few exercises that are the exception to this foundation and in which techniques of inhaling and/or exhaling through the mouth are used.
2. Feeling the diaphragm is essential; it is here where the strength of  breath with good quality and technique reside.
3. Hold your breath.
4. Control exhalation and make it longer than inhalation.

The complementarity of the different approaches to breathing training meets five clearly defined objectives as briefly explained below.

The 5 specific objectives of WBTP:

1. Automate nasal breathing. Accustom the respiratory system to consciously use only the nose to inhale and breathe. (This concept seems very basic, but poor breathing habits and weak diaphragm make many people breathe through the mouth).
2. Strengthening of the diaphragm.
3. Increase tolerance to CO2, increase the capacity of VO2 max and stimulate the release of EPO.
4. Boost the natural production of NO (nitric oxide).
5. Induce the relaxation of the organism.

When maintaining a systematic and progressive training program in different pragmatic techniques of breath-holding and movement meditation like the WBTP, we can develop the IR to its full potential.  The effect obtained is a positive influence on essential aspects of life, defined in BLW series as the 5 distinctive attributes of the individual:

Individual Attributes of IR

1. Mental focus: deep concentration is achieved by programming the subconscious, and in this way, the mind is prepared to function better in future events.
2. Persuasive leadership: the search for the permanent improvement of the personal status quo is one of the proposals of the WBTP, by generating a mentality of competition against itself through superior self-knowledge. This tends towards leadership based on persuasion, in which conviction and intrinsic motivation are the priority.
3. Sharp decision making: WBTP positively activates the parasympathetic nervous system, which ensures an individual has exceptional control of emotions as well as greater clarity in decision making.
4. Good health: with WBTP training higher relaxation levels are obtained and the release of nitric oxide (NO) is enhanced; two vital conditions that help neutralize the toxic effects of stress and anxiety on the body.
5. Peak physical performance: it adapts to the body to tolerate high levels of concentration of carbon dioxide (CO2), this produces an increase in VO2 max, and also increases the production of EPO; these two conditions have a positive impact in the capacity of the blood to transport oxygen, that is, better performance in physical endurance sports.

Bibliography

Escrivá de Balaguer, José María.(|934) Camino.

Manga, Ela and Edward, Viola.(2020) Breath Quotient, Observations of Breath Intelligence,

Yoga, Benefits are in Breathing Less, Measure Progress in Health using DIY Body Oxygen Test to Defeat Symptoms and Diseases with Smart Yoga. Rakhimov, Arthour.

Panneton, Michael.(2013) The Diving Mammalian Response,

US MARINES MCO 1553.3A Unit Training Management, (2016)

PADI Freediver Program Intructor Guide, (2017)

Pelizzari, Umberto. (2016) Manual of Freediving. Underwater on a Single Breath,

Divine, Mark.The way of the SEAL, (2013) Think Like an Elite Warrior to Lead and Succeed,

Cajina, Gregory. (2015) Tu Mente es Extraordinaria.

Vivekananda, Swami.(2012) The Science of Btreathing,

Grinfield, Ben. (2014) Beyond Training, Mastering Endurance Health and Life,

Mcnab, Chris.(2002) Endurance Techniques

Doidge, Norman. (2008) The Brain that Changes Itself, Stories of Personal Triumph from Frontiers of Brain Science,

Sigman, Marino.(2015) La vida secreta de la mente.

Kaheneman, Daniel.(2012) Pensar Rápido, Pensar Despacio

Bryan, Nathan. Ph.D (2010) The Nitric Oxide Solution,

McGonigal, Kelly Ph.D-(2015) Upside of Stress: Why Stress is Good for you, and how to get good at it. 

Cortright, Brant Ph.D- (2015) The Neurogenesis Diet and Lifestyle

Long, Ray. MD. (2014) The Key Poses of Yoga

McKeown, Patrick. (2015)The Oxygen Advantage, the Simple, scientifically proven breathing techniques for a healthier, slimmer, faster and fitter you.

Severinsen, Stig Avall. Breatheology, (2012) The Art of Conscious Breathing.

Chiozzotto, Roberto, Pelizzari, Umberto, Mana, Federico, (2015) Dry Training for Freediving

Mana, Federico.(2013) Breathing Techniques for Freediving

Friel, Joe. (2016) The Triathlete Training Bible

Golding, Dan.(2016) Triathlon Winning at 70.3 How to Dominate the Middle Distance,

Coates, Budd. (2013) Running on air The Revolutionary way to run Better by Breathing Smarter

Grinfield, Ben.(2014) Beyond Training, Mastering Endurance Health and Life

Know, Lee. Life, (2014) The Epic Story of our Mitochondria

Nichols, Wallace.(2014) Blue Mind

Wolfson, Jack. (2015) The Paleo Cardiologist, The Natural  Way to Heart Health

Kaheneman, Daniel. (2012) Pensar Rápido, Pensar Despacio

The Editors of TIME (2016) Mindfulness: The New Science of Health and Happiness.

Habif, Daniel. (2019) Inquebrantables

Strom, Marx. (2010) A life worth Breathing

Donnelly, Darrin. (2016) Think like a Warrior,

Rakhimov, Arthour.(2019) Yoga, Benefits are in Breathing Less

Mac Gregor Kino. (2013) The Power of Ashtanga Yoga

Cohen, Michael.(2020) Neurofeedback, Rewiring the Brain for ADHD, Anxiety, Depression and Beyond.

Elisha Glodstein, (2016) Descubre la felicidad con mindfulness