Introduction

When we think of someone who works out a lot, we typically think of a marathon runner with sinewy legs or a body builder with bulky, bulging muscles. Both of these body types are displaying a phenomenon know as muscle plasticity. Muscle plasticity is the ability of muscle to change to meet the demands that are placed on it.¹

The Diaphragm Muscle

Muscle can change in a variety of ways; either it grows in mass, like the body builder's muscle, due to heavy loads placed on it for a short period of time. Or, muscles can adapt in efficiency so they can be used for a long period of time for low stress loads, like running.

Muscle plasticity works in the opposite direction too. Since muscle tissue is expensive for the body to maintain and repair, muscles that aren't challenged will diminish in size and efficiency resulting in muscle loss or muscle atrophy.²

One set of muscles in the body that are used most includes the muscles of the respiratory system. Researchers estimate that finger muscles are in use about 2% of the time. Lower leg muscles like the calf are in use about 15% of the time. Respiratory muscles like the diaphragm, which makes us inhale, are in use about 40% of the time. Thus, managing and maintaining healthy respiratory muscles is priority.

The Uniqueness of Respiratory Muscle

The respiratory muscles are like other muscles in most ways. For example, the jaw muscles have a wide range of pressure they can induce, the difference between trying to bite a thread with our incisors versus chomping on an ice cube with our molars. Respiratory muscles also display a dynamic range, from the slow steady breaths we exhibit while whispering, the huge gasping breaths we need for hard exercise or the short, percussive exhales we use to sing a Fa-la-la-la-la, La-la-la-la. Thus, just like all the other voluntary muscles in the body, we have control over our breath.

However, respiratory muscles also can function automatically, completely without conscious control. We keep breathing even when we're doing something engaging and not consciously thinking about breathing, like when we're reading a book or sleeping. In this instance, the need to inhale is triggered by sensors in the brain measuring the oxygen, carbon dioxide and acid/base balance in the blood3. This is a completely involuntary system that occurs without conscious thought, just like the heart beating, or food being digested. The standard mode of breathing is this automatic control of the breath. When we speak, shout, hold our breath, sing or play the flute, we are overriding the automatic system with the voluntary system of breath.³

The Science of Conscious Breath

The autonomic nervous system is the branch of the nervous system that controls non-conscious breathing. This system has a 'gas pedal' and a 'break' which vie for control and leave the body in either a more elevated 'fight or flight' state or a calmer 'rest and relax' state. Most people experience chronic stress and fall on the side of the 'fight or flight' state and spend relatively less time in the 'rest and relax' state. This is implicated in a variety of chronic disorders, both physical, like heart disease and high blood pressure, and mental, like depression and anxiety.³

Controlled breathing exercises have been studied as a way to engage the 'rest and relax' part of the nervous system and reduce the effects of chronic stress. Studies show that short bouts of deep breathing have an immediate, transient affect on heart rate, an indicator of degree of stress and 'fight or flight' response.⁴ Further practice of deep breathing exercises, can reduce the overall degree of 'fight or flight' and increase the 'rest and relax' control of the body.⁴

Control of Breath, Control of Stress

Most people are unfamiliar with methods of deep breathing; yet deep breathing practices have been around for thousands of years and have been heavily studied as a wellness intervention. Below are two common deep breathing techniques that have documented evidence for engaging the 'rest and relax' part of the nervous system to counter the affects of chronic stress in modern society in both our body and our mind.^{3, 4}

Victorious Breathing Technique (also called Darth Vader Breathing Technique): This deep breathing technique creates intentional airway resistance in the back of the throat to slow the breath. Most of us aren't aware we can do this until we attempt to mimic Darth Vader. We use the same constriction in the back of the throat to do make the audible sustained inhale and exhale in this deep breathing technique as we do when we imitate Darth Vader. The trick is to continue to using the same constriction with the inhale as with the exhale. This technique can dramatically lengthen the breath cycle. We usually inhale and exhale about 12 and 20 times per minute but with practice, this technique can yield 2 to 4 breaths per minute.

Alternate Nostril Breathing: In this breathing technique we use our fingers to open and close our nose when we are breathing, as if we were plugging our nose due to a stinky smell. However, instead of closing both nostrils at once, we close one nostril at a time, alternating back and forth between each nostril after the inhale. This helps keep us consciously engaged with the breath rather than spacing out and forgetting that we are doing deep breathing practices.

The directions for alternate nostril breathing include:

• The right nostril is closed with the thumb. Air is exhaled through the left nostril, and inhaled back through the same nostril
• The left nostril is closed with the ring finger. Air is exhaled through the right nostril, and inhaled back through the same nostril.

Regular practice of these deep breathing techniques for as little as ten minutes per day confer health benefits to both the physical conditions like heart disease and blood pressure and mental health conditions like anxiety and depression.