The Science Behind Breathing

Our autonomic nervous system controls involuntary activities in the body like heart rate and digestion. Broken into two branches that function as dials, the sympathetic nervous system controls and stimulates an activating ‘fight or flight’ response, preparing you for perceived danger or arousal. The other branch, the parasympathetic nervous system, controls and stimulates your ‘rest and relax’ response, guiding you into a calm state.

Breathing is one exception to the autonomic systems in that it functions automatically and you can voluntarily control it. Because all of our autonomic systems are intricately linked, voluntarily changing your breathing rate or pattern can cause windfall effects throughout the entire body. Studies have shown breath practices reduce symptoms of stress, anxiety, insomnia, PTSD, obsessive-compulsive disorder, attention deficit disorder, and schizophrenia.


Breathing exercises have the ability to activate the vagus nerve, a winding cranial nerve that links the brain to organs, letting the heart, lungs, and digestive system know when to beat, breathe, digest, etc. The vagus nerve not only carries messages from the brain but to the brain, connecting and communicating many seemingly disparate autonomic functions that influence stress response and emotion.

As respiration is the only autonomic function we can control, breathing gives us the ability to influence the rate at which these impulses are transmitted, remaining calm yet alert. When we elongate the exhalation, in particular, we stimulate the vagus nerve and direct ourselves into a parasympathetic, relax and renew state.

Another Peak Flow® practice that has an influence on anxiety and panic, in particular, is breathing less—practices that not only slow the breathing rate but actually decrease the amount of air we breathe. Breathing less has the ability to increase our tolerance to Carbon Dioxide which, much like breathing into a paper bag, can short circuit the experience of panic. Increased levels of CO2 can calm your amygdala and synchronize heartbeat and breathing rhythm.


Under stress and anxiety, breathing exercises have the ability to stimulate the parasympathetic nervous system and suppress the sympathetic nervous system, sending messages along the vagus nerve to direct ourselves into a relaxation response. As respiration is the only voluntary function of the autonomic nervous system, we can use the breath to decrease our heart rate, slow respiration, reduce levels of cortisol, and more.


Utilizing different breathing patterns can act as a remote control on your state of being through different physiological pathways; some we are aware of and some we have yet to discover.

Studies show that by incorporating high-frequency breathing, people can increase their ability to sustain attention and direct attention, suggesting an increased state of wakefulness. This state is believed to be achieved through activating the sympathetic nervous system and reducing vagal activity.


The ability to focus your mind is a skill that many face challenges with. There are multiple breathing practices that have shown evidence to increase an individual’s ability to focus, sustain focus, and shift focus.

In one study linked below, researchers at the Feinstein Institute for Medical Research discovered that different breathing patterns affect widespread regions in the brain, far beyond just the brain stem as previously believed. The insula and the anterior cingulate cortex, a brain region involved in moment-to-moment awareness were able to be activated which correlates breathing practices to heightened attention.

Another study found that individuals increased their ability to sustain and direct attention by using high-frequency breathing. This state is believed to be achieved by activating the sympathetic nervous system and reducing vagal activity.


Difficulty sleeping has been correlated with autonomic nervous system dysfunction, specifically in relation to vagal activity and the vagal nerve. When we engage in specific breathing practices we can suppress vagal activity and in turn, improve our sleep. Many of our practices for sleep utilize an elongated exhale to increase vagal tone or even humming on the exhale. These breathing exercises activate our parasympathetic nervous system, the system involved with our rest and repair operations. This parasympathetic activation and sympathetic suppression induces what has been called the relaxation response and helps us fall asleep and stay asleep.


There are clear correlations between sleep apnea and nasal obstruction. Sleeping can emphasize and condition our airways to route our breathing through our mouths, which can lead to chronic over-breathing. We can reduce sleep apnea and snoring by clearing the nasal pathways and consciously directing our breathing through the nose, reducing breathing volume altogether. This may seem counter-intuitive to what we have been conventionally taught but it supports the notion that breathing less is actually a key to greater health and well-being. In one study linked below, improved nasal breathing decreased snoring in 34% of participants and daytime energy levels were improved by 78%.


This is one of our favorite areas to explore: breathing as an intervention for pain perception. In one study we have linked below, pain perception is reduced when the pain is applied during holding the breath in after a deep inhalation, what we call apnea. These results demonstrate that easy respiratory practices can be used to reduce our perception of pain.

In another study, slow and deep breathing was essential in modulating the sympathetic nervous system and our perception of pain. It found that the way we breathe decisively affects our autonomic nervous system and can reduce tension and anxiety surrounding pain.


It is difficult to talk about breathing and cardiovascular health without mentioning Nitric Oxide. Nitric Oxide is a vasodilator gas that is produced in the paranasal sinuses and when we breathe through our nose; it is excreted through our nasal airways. As a vasodilator gas, Nitric Oxide naturally opens our blood vessels when we breathe through our nose.

One review, linked below, suggests that slow, yogic breathing techniques produce a beneficial effect on the cardiovascular system by affecting autonomic variables. This plays a role in cardiac function such as blood pressure and heart rate.


Slow and balanced breathing activates the parasympathetic nervous system. The autonomic nervous system was conventionally thought to function automatically but we have found that through conscious breathing exercises we can influence these systems voluntarily. When we slow our breathing down we suppress the sympathetic nervous system and kick-start our relaxation response. This can decrease the heart rate, dilates our blood vessels, and also reduces our blood pressure.


Heart rate variability is the variation in time between beats of your heart. Low HRV reflects a more constant interval of time between beats and has been shown to improve things from sports performance to asthma symptoms to IBS symptoms. The practice of taking 6 breaths per minute—slow breathing—improves HRV.


Personalized Breath Training is Key

Breath training is not a one-size-fits all approach. 

At Peak Flow we are unique in our ability to prescribe breathwork personalized to your individual needs, psychology, and biology, to directly benefit your health and performance. Using our Peak Flow method and ecosystem of breathing exercises, we meet each human where they are at and build a breath plan inspiring them to reach their goals.

Additional Resources

Additional Resources

“Humans are happiest when they feel in control of their inner thoughts and feelings and experience a ‘flow’ state,” explains pioneering psychologist and researcher Mihaly Csikszentmihalyi, leading to “a sense of purpose, enjoyment and meaning.” 

  • Buteyko Clinic International
  • Oxygen Advantage
  • Wim Hof Method

“Our brains are like muscles,” explains Stanford University researcher Dr. Andrew Huberman of the Huberman Lab podcast. “Regular titrated doses of attention, reward, and reinforcement develop (un)healthy habits and behaviors.” In other words, incorporating the ten elements into daily living and building a healthy foundation to support breathwork leads to lasting transformation over time.

Strategic Breathing Protocols, Breathing Exercises, & Breathwork Info

More breathwork strategies, breathing exercises, and information and resources related to strategic breathing:

Patrick McKeown

“My mission is to empower people to take control of their own health, well-being and fitness using simple breathing exercises proven to improve body oxygenation” – Patrick McKeown.

World- renowned author and breathing practitioner Patrick McKeown was educated at Trinity College in Dublin, before completing his clinical training in the Buteyko Breathing Method at the Buteyko Clinic, Moscow, Russia. This training was accredited by Professor Konstantin Buteyko. Patrick continues to have a tremendous impact on breath and educating millions around the world..