When I asked a group of school age yoga students recently if they knew how to breathe, many of them giggled and looked at me quizzically. Adults, realizing that this is partly a rhetorical question often look perplexed. The reason that this is one of the first questions out of my mouth to a new group of students is because American society is plagued by the habit of reverse breathing.

The signs of reverse breathing are easy to spot. If, as we breathe, the belly contracts as the chest expands, we are reverse breathing. A properly drawn breath begins with the diaphragm, the sheet of muscle suspended between the ribs that separates the chest (thoracic) cavity containing the heart and lungs from the abdominal cavity where many of our vital organs reside. The diaphragm is responsible for 75% of our respiratory flow while the intercostal muscles that knit the ribs together take care of 25%.

During reverse breathing the diaphragm’s role is diminished as it retracts impotently in a feeble upward motion. Ideally, the diaphragm should push downward to open the lungs to receive the inhalation.

“So what,” you might say? “As long as air gets into the lungs, what’s the difference?” The difference is huge, Mt. Everest huge. Full activation of the diaphragm and intercostal muscles are essential and fundamental to basic health and well being.

Diaphragmatic breathing stimulates the vagus nerve. This cranial nerve descends in branches through the torso and the diaphragm itself and “supplies motor parasympathetic fibers to all the organs except the suprarenal (adrenal) glands, from the neck down to the second segment of the transverse colon.”[1] It is responsible for heart rate and digestive peristalsis, the motion of the intestines that digests food and eliminates waste. Recent research suggests that the vagus nerve may even respond to signals from bacteria in our intestines, and that signal is then conveyed to the brain. When the diaphragm and intercostal muscles are not fully utilized, these functions are inhibited, and that is seriously bad news.

The vagus nerve controls the parasympathetic nervous system which controls the relaxation response.[2] When the diaphragm is fully utilized, the neurotransmitter, acetylcholine, is released. Acetylcholine not only helps induce relaxation, but stops inflammation from beginning its insidious work of causing disease.

Breathing just into the chest without using the diaphragm does not stimulate the vagus nerve, and leads to stress and chronic tension. Chronic stress and tension are seed beds of disease. Without vagus nerve stimulation, heart rate regulation is inadequate, relaxation is nearly impossible, immune system activity is dampened and the door to disease is wide open.

In my experience as a yoga teacher and yoga therapist, I find that reverse breathing is pervasive in our society. It is no coincidence that some of my most seriously ill clients are chest breathers. The first thing I check when I begin to work with a new client is the breath.

So, what has got us breathing in this abnormal fashion? The word fashion is key to the reason for this disease-courting breathing technique. Somewhere in the past, it became “fashionable” to abandon a normal healthy breath for the plague of reverse breathing. Did it begin when corsets came into fashion? Trying to draw a diaphragmatic breath with your abdomen strangled between whale bone stays and tightly tugged strings is impossible. Chest breathing is the only alternative. Did it start as an evolutionary trait to make our selves look bigger to potential predators? Does the military “suck in your gut, throw out your chest and cock your shoulders back” like a loaded spring have anything to do with it? I’d bet it’s a bit of all these things and more.

But when I ask kids to tell me how to breathe, invariably I get some who tell me that proper breathing begins in the chest. I suspect this instruction is coming from their parents or other adults in their lives.

The obsession to appear attractive and fit in the U.S. and other western countries is a nearly irresistible social pressure that encourages reverse breathing and begins to sow the seeds of poor health, disease and early mortality.

An eight year-old girl in one of my classes this summer told me her mother had instructed her to breath into her chest and suck in her belly. This girl is perfectly height/weight appropriate, but I suspect the mere notice of her belly may well be an affront to her mother’s sense of what’s attractive. I noticed that this child was more anxious and in need of attention and assurance than many of the other children. Breathing into her belly felt “weird” to her.

Perhaps I’m going out on a limb here, but I’d bet that if we could correct this disastrous trend of reverse breathing, we’d see healthier, more relaxed human beings. The implications of that extend into every thread of human endeavor. Think for a moment what a world of relaxed, balanced human beings might be like.