Breathing, the Center of Life

The quality of the breathing determines the quality of the life. Breathing is unique among body functions in that it can be entirely involuntary and unconscious, or it can be almost entirely voluntary, or a mix. Voluntary control can be automatic, forgotten and unrecognized, and it is this automatic but voluntary over-control that is the culprit in most dysfunctional breathing.

For the most part, it is generally thought that improving breathing means increasing breathing in every way, but this may be too simple an idea. The mere admonition to breath deep, or breath "more" often leads to a willy nilly increase in both rate and volume of breaths, and a large increase in minute volume (the number of liters of air exchanged between lungs and atmosphere in a minute.) What is most important, is the smooth flow of the breath wave through the chest, abdomen and pelvis.

Breathing has four general functions: 1) Taking oxygen into the body 2) Regulating the level of carbon dioxide in the body, 3) Starting and maintaining pulsation in the body, and 4) Balancing the autonomic nervous system between sympathetic and parasympathetic. Mainstream healthcare concerns itself largely with the first and marginally with the second (at least in the context of 'disease') but ignores the latter two. For bodywork, however, these functions are equally important.

Breathing also regulates the metabolism. One way it does it may do this through the thyroid that is placed around the trachea (windpipe). The mechanism by which it does this not known, but the placement of the thyroid cannot be random. The amount of air intake seems possibly to be a candidate for driving the thyroid but velocity or some other factor may be operative. Having a relatively tight or narrow throat is a common condition in our age. Reichian vegetotherapy put a strong emphasis on opening the throat. A common pattern for the thyroid (as with the adrenal) is to become fatigued at midlife, and perhaps less dynamically responsive to breathing.

Some also believe that breathing acts to take in energy (in addition to oxygen) from outside the body. This is perhaps the most controversial way to look at the function of breathing. With Wilhelm Reich, this idea was subsumed into the larger idea of life energy, or orgone. Alexander Lowen did not emphasize this concept, and this article will not pursue it.

Autonomic Effects

Breathing high in the chest with shoulder and accessory muscles leads to sympathetic dominance. Using the diaphragm to push (or 'let') down into the abdomen and pelvis balances autonomic tone back toward the parasympathetic. Pausing after the inhale (also known as holding the breath) leads to sympathetic dominance and also reduced feeling. Pausing after the exhale (rather than gasping or quickly 'sucking in' a breath) allows the involuntary inspiratory reflex to initiate the breath which has a parasympathetic effect. The relationship between breathing and autonomic tone is truly bidirectional, as will become clearer as this discussion continues.

Respiratory Sinus Arrhythmia (RSA) is the reflex in which heart rate speeds during inhalation and slows during exhalation. This is prominent in children but almost disappears in most adults. Since RSA seems to represent autonomic flexibility, this disappearance is not healthy. It is perhaps through this reflex that breathing regulates autonomic state. Stephen Porges has based his research techniques on poly-vagal theory around this measurement.

The most common misunderstandings about breathing deal with gas exchange, and so this page discusses it at length, but gas exchange is just part of healthy breathing. The energetic, nervous, and emotional regulation of the body provided by the 'wave' of deep smooth natural breathing, from head to pelvic floor and back, (what Reich called the orgastic reflex) is basic to health.

Oxygenation and Carbon Dioxide Exchange

One main goal of improved breathing is in fact making oxygen available to the body. Good feelings in the body rely on plentiful oxygen in the tissues. However getting more oxygen to the tissues is not as simple as a naive understanding might make it. Of course, the start of oxygenation is the exchange of gases between the lungs and the bloodstream. Because the concentration (known as partial pressure) of oxygen is approximately the same in the atmosphere as it is in plasma leaving the lungs (of any reasonably healthy person), it is often stated by skeptics that it is not possible to take in more oxygen by improving breathing or changing breathing patterns in anyway. This is partly true in that mere increase of air exchange in the lungs will not increase plasma oxygen levels much unless the increase in ventilation is in response to an oxygen deficit in the blood. But Alexander Lowen felt that if ventilation increased consistently, metabolism increased and oxygen consumption increased, so that while the average content of oxygen in blood did not change much, the turnover of oxygen was greater and the body had more energy. But oxygen is only a back up regulator of breathing, and carbon dioxide exchange is the fine tuned primary regulator of breathing.

The real site of oxygen deprivation is the tissues, not the lungs. This deprivation has three mechanisms, a weakened 'Bohr' effect, anemia, and constriction of the blood flow to the tissues. The first two have something to do with hemoglobin in red blood cells. Hemoglobin is an immense storage buffer for oxygen within the blood, otherwise the oxygen merely dissolved in the plasma would be used up quickly at the tissue level. However hemoglobin, to load and unload in the right places, needs a switch to control the binding of oxygen. This switch is carbon dioxide. Where carbon dioxide is low (at the capillaries in the lungs, because of rapid diffusion out of the plasma into the alveoli), oxygen is bound to hemoglobin, and where carbon dioxide is high (the capillaries in the tissues, due to metabolism) oxygen is unbound. This is known as the Bohr effect. Nitric oxide is also involved in tissue respiration but this is poorly understood at present.

Anemia (low red blood cells and hemoglobin) greatly reduces the amount of oxygen available at the tissues. The oxygen detectors in the large blood vessels do not stimulate attempts at better breathing in any way with anemia because they respond to the partial pressure of oxygen and not the total content of oxygen in the blood, but it is the latter that determines the amount of oxygen at the tissue level. Chronic anemia, chronic illness, and chronic poor breathing are all correlated, but the cause and effects relationships are undelineated. Could chronic anemia sometimes be an adaptation to poor breathing? A way to protect a constricted body from the pain of more life force? Almost all folk traditions associate life force both to blood and to breathing.

Constriction of blood flow is caused by sympathetic shift and low carbon dioxide. Carbon dioxide is a vasodilator. Also chronically tight muscles restrict blood flow. Much of the pain experienced in connective tissue and muscle may in fact be from low blood flow, especially low back pain. Also capillaries, the tiny blood vessels that deliver blood to the actual tissue, may be more or less plentiful depending on the oxygen dynamics in the body. Oxygen availability to the tissue decreases sharply as the distance to the nearest capillary increases.

So it is a serious error to consider carbon dioxide purely a waste product. Because metabolism constantly produces more carbon dioxide, it is true that some carbon dioxide must constantly be removed from the body. However in physiological concentrations, carbon dioxide acts like a hormone. Besides the Bohr effect, carbon dioxide dilates blood vessels and bronchioles, and soothes nerves. Of course if over retained, carbon dioxide becomes toxic, but retention of carbon dioxide is actually very difficult unless there is advanced lung disease. The following distinction will help explain why:

The diffusion of oxygen from the lung to the blood benefits from a pressure gradient as well as a concentration gradient. That is why most blood oxygenation occurs during exhalation, when there is positive pressure in the lungs. This alone is good reason for longer slower exhalations. Carbon dioxide, however, diffuses easily from blood to lung, and of course inspired air has almost no carbon dioxide, so the concentration gradient is very steep as well. As a result, short breaths favor the loss of carbon dioxide in the process of oxygenation. Short breaths probably guarantee rapid breathing because the body suffers at least tissue hypoxia, but rapid breathing makes the imbalance worse

So if carbon dioxide builds up in the plasma, in reasonable healthy lungs it will rapidly diffuse into the alveoli in higher concentrations, and since inspired air has almost no carbon dioxide, it will wash out strongly when the next breath occurs. This is a rare event however, since the body is very intolerant of increased carbon dioxide levels. Even in vigorous so-called aerobic exercise, the tendency is hyperventilate (which can be 'combated' by breathing through the nose).

But carbon dioxide depletion is very easy, as described in the sections below on hyperventilation.

In fact, the regulation of breathing is more organized around the close regulation of carbon dioxide than around the immediate regulation of oxygen. The breathing center in the brain paces breathing according mainly to carbon dioxide level. Peripheral 'chemosensors' monitor oxygen partial pressure but they kick in activate breathing only secondarily. The the sympathetic nervous system has the role of decreasing carbon dioxide level. It does this by 1) faster breathing, 2) broncho-dilation. The parasympathetic nervous system has the role of retaining carbon dioxide. It does this by 1) slower breathing, and 2) broncho-constriction. Contrary to some assertions, the function of broncho-constriction is not to limit oxygen but to retain carbon dioxide (and also enhance oxygen diffusion by creating 'back pressure' on exhalation.) It makes sense to 'start dumping' carbon dioxide when beginning strenuous activity, but sympathetic shift keeps many people dumping it all day and all night, as detailed below in the section on chronic hyperventilation. Short of extreme exertion it is optimal to breath through the nose because the airway resistance is additive between the bronchial system, throat, and the nose.

Aerobic Exercise

During sustained vigorous exercise, the muscles use up much more oxygen and produces much more carbon dioxide. This is the one situation in which rapid breathing and increasing the amount of air exchange per minute in the lungs is warranted. Still it is possible to breath dysfunctionally while exercising. Rather than pushing the effort to the extreme and gasping willy-nilly, it is beneficial to keep the pace to the point where one can still breath through the nose, as discussed in the section above.

Aerobic exercise has from the 1970s to the present day become very popular as a path to health. One thing to keep in mind, is that aerobic exercise induces hypoxia at the tissue level, which is dysphoric. However in response to this hypoxia and pain there is a strong release of endorphins, which provide a much stronger euphoria. This is 'runner's high' which is not from oxygen! During aerobic exercise, blood is shunted to the muscles away from the surface, which is also what happens in 'fight-or-flight. Heavy aerobic exercise regimens produce a sympathetic-shift and hard shortened muscles. Of course, some of the training effects of aerobic exercise, such as increased hemoglobin and decreased heart rate, benefit resting oxygenation somewhat.

Acute Hyperventilation

Reichian and neo-Reichian therapy is 'famous' for instructing clients to lie down and hyperventilate greatly. It is often thought that this is about increasing oxygen, but as the above discussion shows, this is not the case. Many writers in the Reichian tradition, have attributed the effects brought by acute hyperventilation to an increase in body oxygen, but I can only conclude this is an error in understanding. Not only does this not increase oxygen, but is probably the effect of brain tissue hypoxia and blood alkalosis from hyperventilation as described above. Alkalosis causes vasoconstriction, so that while the autonomic system usually responds very promptly to correct brain hypoxia, in the case of hyperventilation it cannot. An important consideration, is the possibility that over many reasonable sessions of increased breathing, metabolism may be stimulated, and oxygen consumption and carbon dioxide production increases. Alexander Lowen suggested this based on his experience that over time his symptoms of alkalosis like tingling and cramping stopped. As described under the section below on chronic hyperventilation below, this adaptation doesn't seem to happen if there is not attention on the quality and shape of the breath

Actually the therapeutically pertinent effects of acute hyperventilation are: 1) developing a sympathetic based charge in the muscles and nerves in anticipation of discharge, and 2) disinhibiting emotional expression and increasing emotional arousal, 3) loss of control over the musculature through cortical dimming.

Traditional Reichian based work consisted of building charge through deliberate hyperventilation, working with discernable blocks in the distribution of charge over the body, and bringing about discharge. Charge in this sense related to a build up of nerve impulses producing contraction of the muscles in anticipation of discharge. A psychological correlate of this situation is usually the urge to do or express something. The 'charging' or sympathetic-tending state was intensified by bending the hip flexors. Discharge came through straightening the hips and letting breathing go, which with a healthy autonomic system allowed a compensatory swing to the parasympathetic. 'Charge' is not identical to vitality, life force, or libido but is rather a temporary physiological state. Charge is uncomfortable if held without the ability to discharge, but a healthy pleasure function requires the ability to build charge and hold it for deep discharge. Acute hyperventilation occurs spontaneously before the sexual climax, and this is a charging function. There is also the idea that blocks can be 'attacked' from 'underneath' by building a strong charge and 'blowing the top off.'

Second, hyperventilation allows the more ready perception and expression of emotion. For anyone relatively distanced from his or her emotions, this can be very informative. There is also a cathartic release (a release is not the same as a discharge) and there will be a sense of calm and well-being afterwards.

Third, because of hypoxia, the baseline muscle control that the brain constantly conducts, slips away. This makes the person much less able to deliberately use muscles, but makes the muscles response to involuntary discharge much more intense. Brain imaging has shown that in low oxygen states the cerebral cortex activity (thinking) dims considerably more than the limbic system activity (feeling). This cortical dimming, along with muscle disinhibition can produce euphoria and a sense of freedom.

Acute hyperventilation is not well suited to self-help or homework because the likelihood of dissociating and losing grounding and contact is high. While Wilhelm Reich used this practice, Alexander Lowen largely dropped it, using the bioenergetic stool instead to increase depth and excursion at normal rates of breaths per minute.

Acute hyperventilation has been used traditionally in religious and other movements to create an 'oceanic' less earth-bound feeling. While this may have some utility in freeing work, the insights from these moments certainly are not a reliable guide to growth or living! In this day and age where chronic hyperventilation is becoming the norm, one wonders whether this acute hyperventilation is still as effective in providing a 'different' experience.

Many variations of 'rebirthing' movements developed in the 60s and 70s entirely around the subjective effects of severe acute hyperventilation, which was pursued almost in a competitive fashion. This seems to be the misguided confusion of an intensely altered state with a profoundly meaningful state. The naive idea also arose that carbon dioxide was a toxin, and that ridding the body of it was all good.

In recent years, a medical technology pulse oximetry has become more widely available.. Oximetry measures, using infrared light shone through a nail bed, the percent saturation of hemoglobin, since hemoglobin turns a brighter red when bound to oxygen. In medical settings this is used as a screening test to non-specifically catch catastrophic issues of gas exchange. It has been used at times by breathing hobbyists to try to validate their undertakings. What must be made clear is that oximetry indicates nothing about carbon dioxide and nothing about oxygen availability at the tissues. It is completely uninformative about non-immediately life threatening aspects of breathing.

Blood alkalosis/brain hypoxia is horribly misused in the incredibly dangerous fainting or choking game of children, and the incredibly dangerous autoerotic asphyxia. The misguided goal is to achieve new sensations or a stronger involuntary muscle discharge due to cortical dimming. To do this, hyperventilation, which by itself would usually be self-limiting, is used with strong vagal maneuvers to delay the return of breathing, and/or strangulation to decrease blood to the brain. This creates an often fatal combination responsible for many deaths a year. This sadly shows perhaps, how strong the craving is for non-ego-mediated good feeling.

Chronic Hyperventilation

Chronic hyperventilation, on the other hand, is increasingly common in our fast-paced culture. The sympathetic system when activated tends to increase air exchange in the lungs in anticipation of greatly increased carbon dioxide production through physical activity. If this does not happen, hyperventilation ensues. In our keyed up lifestyle the hyperventilation becomes chronic. The blood maintains its necessarily narrow pH range by kidney excretion of bicarbonate. This makes the buffer system more shallow however, so that a chronic hyperventilator, if he or she should have an acute episode of overbreathing, will experience more severe symptoms, like panic attacks. Seemingly the carbon dioxide set point in the brainstem is reset, and changing back to better breathing may feel wrong at first. This resetting of the 'carbo-dioxide-stat' may be a contributor to sleep apnea, which is becoming epidemic.

Ironically, the capacity for physical exertion is reduced. For one this is because there has developed a maladaptive intolerance of 'higher' levels carbon dioxide as are caused by physical work, and so breathing becomes very uncoordinated and gasping with even semi-strenuous activity because the body feels it is asphyxiating. For another, the stymied Bohr effect as described above is unable to 'turn on the spigot' at the tissue level. It is unclear what the relationship is between chronic hyperventilation and thyroid function.

The brain has the time to compensate through some unique mechanisms, so brain hypoxia is less than in acute hyperventilation, and there is no cortical (mental) dimming, but tissue hypoxia is chronic and affects feeling and function negatively. Mouth breathing greatly accelerates hyperventilation. Talking forces mouth breathing. It is interesting that chronic hyperventilation is a taboo-ish subject in allopathic medical circles. Opposition to moderating ventilation rates and volume seems to have a moral fervor to it. Perhaps in our culture the over-riding worry about 'getting enough air', a fear-driven sensation, is very prevalent subconsciously. Here is a link to a .pdf on the chronic hyperventilation by Patrick McKeown with medical references.

A Russian physiologist Konstatin Buteyko recognized in the 1950s the impact chronic hyperventilation was having on health and disease. He developed a method of reducing air exchange that is effective in reducing the symptoms it targets. From a Reich and Lowen point of view however, the Buteyko method seems oblivious to the other functions of breathing besides gas exchange. Despite working with the breath, the Buteyko method is more allopathic than holistic.It seems to actually teach respiratory holding and ignores the role of diaphragm and rib excursion.

An interesting tweak is the Frolov device that re-acclimates one's modern 'capnostat' to a higher more healthy carbon dioxide level, at the same time slowing breath rate, strengthening the diaphragm and deepening respirations (by mildly decreasing the concentration of oxygen). The genius of the device is that it uses blood chemistry and not deliberate control, and so overcomes the obstacle of conscious 'voluntary' breathing habits not transferring over to unconscious. 'involuntary' breathing habits. This is holistic in that it seeks to re-regulate a dysregulated system, but will seem too mechanical and unemotional to many. Other methods of improving breathing are described later in this page.

Deliberate Improvement of Breathing

What is always problematic for therapeutic traditions that work with breath, is how to employ a 'student's' conscious use of voluntary mechanisms to 'loosen' the inhibitory effect of 'forgotten' voluntary mechanisms. It is not possible to even pay attention to one's breath without changing it.

Alexander Lowen (like the earlier Elsa Gindler led tradition that has descended through Carola Spreads and Charlotte Selver) also made good breathing primary in his method, but somewhat paradoxically did not think deliberate breathe exercises were of real benefit. I believe that that was because he was thinking of the 'last step' of improvement from fairly balanced but 'held back' breathing to fully free natural breathing. No manipulation of breathing can lead to fully free breathing. Lowen's emphasis, besides stretching the torso, was on freeing emotional expression, which would bring about strong natural breathing indirectly. This is one of the many bootstrapping paradoxes in bodywork, since restricted breathing restricts emotional expression, and restricted emotional expression restricts breathing!

However, what I see around me in the present era is such universally rapid, shallow, and high-in-the-chest breathing that I am convinced tremendous betterment can be had reliably and fairly easily by some non-elusive deliberate practices. While I do not believe that breathing exercises alone are sufficient for permanent change, it does seem to me that the need for better breathing is so great, and the effect of even partial improvements are so large, that this area represents the 'low hanging fruit' of bodywork. Below are some general principles of improving breathing. The reader is strongly encouraged to find in this website and other sources specific exercises that he or she finds practical and do them!

Improving breathing does not necessarily mean increasing breathing. The main task for most people is actually slow their breathing rate--breaths per minute-- to about six. If shallow breathing is also an issue (and it almost always is) then slowing the rate tends to enlist more basic breathing reflexes that take care of 'deepening.'

The response to a simple request to breathe "deeper" usually intensifies whatever pattern a person already uses, and increases the rate. The result is hyperventilation at some level. That is why uninstructed 'self-help' is sometimes insufficient in this area. Better breathing can benefit from a skilled enough observer who can point out what type of breathing is actually going on, and perhaps cue doing something different in the cause of breaking a habit.

Breathing consists of an inhale, an exhale, and a pause. All three must be considered. As a rule, inhales need to be made 'lower' in the torso, all the way to the pelvic floor. Exhales need to be spread out much longer and not forced. Importantly, the pause needs to be placed at the end of the exhale instead of at the end of the inhale. The pause should last until the breathing reflex 'kicks in', that is the inspiration should not be initiated prematurely by the will or by fear. If the above three things are accomplished, the rate tends to take care of itself. An optimal breath rate is said to be around 5-8 per minute. Although some breathing exercises use pauses or 'holding' this is best thought of as for the purpose of training respiratory muscle control and not breathing control.

Many breathers are in the habit of cutting the exhalation short (as if afraid of losing too much air) by initiating voluntarily a shoulder- and accessory- led inbreath, and then pausing before exhalation.. This is in fact the startle response made chronic. The shortened exhale, the will-based inhalation, and the holding of the breath all contribute to rapid shallow sympathetic-increasing breathing.

Also, there is a tendency, when breathing deliberately, to tighten the throat a bit, as if the throat made inhalation and exhalation happen (not true). This seems to be a manifestation of 'trying.' It is greatly lessened with nose-breathing, possibly because sensory input from the nose is enough to quell the urge control the breath.

Despite a tendency to simplify better breathing into 'belly breathing', the chest below the shoulders must participate. The ribs must be able to lift slightly and spread apart. This speaks to 'vital capacity.' While sheer air exchange per minute is not an element of health as described above, the chest excursion within a single breath is. The Framingham Study concluded that the best predictor of life expectancy was the amount of air that could be expired in one second (FEV1 (which is a reflection, albeit slightly reductionistic, of vital capacity)).

The tight back and rib muscles that are endemic in our culture prevent the ribs from moving in their articulations with the spine. Some people have a ribcage stuck in expansion and others have a ribcage stuck in collapse. While this has some characterological implications, in the mechanics of breath they pose a similar issue. All stretching techniques that increase spinal flexibility especially twists and side bends will be helpful to free these joints

While perhaps only 30 percent of a good breath is from chest excursion, this portion is important for co-ordination and unity. A rigid thorax may 'lose' more than the 30 percent of potential breath by undermining the functioning of the diaphragm--the extreme form of this situation is paradoxical breathing described at the end of this page. If the ribs form a rigid tube, then even if increased inhalation causes the belly to expand, the shoulders will rise anyway by pressure. The rigid tube will cause air to blow out both ends ('mushroom form'). If the ribs expand like a cone, widest at the diaphragm, they have a role in holding the shoulders down. The best and most direct way to loosen rib movement is a thorough program of regular stretching of the torso.


Pranayama is the practice of breathing exercises within the larger yoga tradition. As such, in its practices, it deals both with the goal of restoring basic health and the goal of spiritual development, without any clear dividing line. They are not intended to be stand-alone practices apart from the other elements of yoga. Still these are time-tested techniques that are probably safe with a qualified teacher. Pranayama has both energizing (arousing or sympathetic increasing) and quieting (parasympathetic) techniques. The goal seems to be increasing autonomic range and flexibility. When taught in the West as something exotic it seems very possible that the hyperventilating maneuvers of pranayama have been over-emphasized due to the seductiveness of the altered states.

The Role of the Nose

A simple but remarkably effective practice is simply to always breath through the nose, even during exercise. Because the nose is very rich in nerves, this stimulates ventral vagal centers, and tends to slow and balance the parts of breathing naturally. Formerly it was folk wisdom to avoid mouth breathing, but these days mouth breathing is very common, and somehow considered rude to comment upon. Since talking causes mouth breathing, an implication is to avoid excessive talking.

Although nasal congestion is thought to be a reason not to nose breath, breathing through the nose decreases nasal congestion. Nasal congestion is not always caused by mucus or allergies as commonly thought. Rather the nose contains turbinates with erectile tissue that swells or shrinks. The turbinate system is often dysregulated due to stress or tension, and can be often re-regulated simply by persevering with nose breathing for a time. The nasal turbinates are not only rich in autonomic innervation, but they lateralized with the right side promoting sympathetic functions and the left side promoting parasympathetic functions

The Role of the Diaphragm

The diaphragm is rigid in many people. A tight diaphragm reduces feeling and emotion immensely, and that is usually why it develops. A tight diaphragm is also usually very weak, and needs strengthening. The diaphragm is the dividing line between the ventral vagal system above and the dorsal vagal system below. For the diaphragm to be able to move down into the abdomen, two things are important. First, the abdominal wall and flanks--the entire lower torso on all sides, must be supple and able to expand. Otherwise, effort to breath more deeply will likely just affect the upper chest. Second the pelvis must be loose and flexible so that abdominal contents can move down into the pelvis. The pelvic floor should actually drop and the angle of the pelvic bowl widen. Attempts to get breath into the belly when the pelvis is narrow and tipped forward may help partially, but will cause a ballooning that probably never feels natural enough to become permanent. A 'packed' abdomen from sluggish swollen intestines and bowel, or from abdominal fat will also limit the capacity of the diaphragm to sink

If the diaphragm has come to have a high starting position above the floating ribs, it will limit the expansion of the ribs, even with a good downward excursion of the diaphragm during inhalation. It can be valuable during the pause before inhalation, to try pushing the diaphragm downward without taking breath in yet, then proceed with a normal deep slow inhalation. Brief experimentation will show if this makes the ribcage feel freer. .

Paradoxical Breathing

This is the situation in which the diaphragm actually rises during inhalation. This occurs when there a very weak or frozen diaphragm. The breather will attempt to inhale by raising the shoulders and elevating the ribs. At the same time the diaphragm is 'sucked' upwards canceling most of the potential space and resulting in a shallow breath despite the effort. Paradoxical breathing at rest may not be obvious but it results in a higher rate per minute of shallow breathing. During exertion, the sucking in of the abdomen will be more visible, and a lack of respiratory reserve is made evident.