I love yoga, and I love hot yoga even more. I was fortunate to enjoy practice at my local studio twice this week, being still and in the moment for an hour each time and listening to the rhythmic voice and centering words of my instructors. Breathe. It's something we all take for granted, myself included. But our breath deserves far more understanding and appreciation than we give it: breath is a powerful biological tool that not only sustains life but also can profoundly enrich our health in a variety of ways.
Yogis have valued breath for thousands of years calling its practice pranayama meaning control of the life force. But how exactly does breath yield life? What makes breath our prana? It gives us oxygen - that's a given - but why is oxygen required for survival? Here is the answer - be ready to love your biology : )
Oxygen is what enables metabolism to occur - that's right, the same metabolism we associate with diet and exercise! In its most basic form metabolism is the breakdown of dietary carbohydrates and fats and the conversion of these molecules into energy. While many of us imagine energy as as invisible force directing the world, in our bodies energy is a tangible molecule called adenosine triphosphate, abbreviated ATP.
ATP is a form of chemical energy. Through removal and transfer of its terminal phosphate groups (the P and OH atoms at the end of the molecule), it drives the molecular reactions of our cells. Cells make-up our tissues and organs. Therefore, as cells carry out their unique functions using ATP as a power source, our organs are driven to perform their life-sustaining roles. Our heart beats. Our digestive tract moves water and nutrients into our blood. Our neurons fire and send signals to our periphery. Cells must synthesize on average 68 million ATP molecules per second to keep their tissues and organs functioning.
So how does oxygen support ATP synthesis? ATP is produced through cellular respiration, the biochemical process that consumes the oxygen we breathe in and yields the carbon dioxide we breathe out. In addition to oxygen, one of two other molecules is required to make ATP: glucose or fat. This is how dietary carbohydrates and fats fuel our bodies; they take part in cellular respiration as reactants enabling energy production. The net equation for cellular respiration using glucose as a starting reactant is:
1 glucose + 6 oxygen (O2) --> 6 carbon dioxide (CO2) + 6 water (H2O) + 38 ATP
The equation using fat is slightly more complicated but oxygen is still a reactant, carbon dioxide is still a product, and the number of ATP produced is in the hundreds. Thats right, fats yield significantly more energy than carbohydrates do because of their complex molecular structures. This is also why, on a nutrition label, fats contain more 'calories' per gram than carbohydrates or proteins: because calories are a measure of a nutrient's potential for generating ATP in our body.
In the absence of oxygen, termed anaerobic (without oxygen) respiration, our cells can make only a very small amount of ATP (two to be exact): a level that is insufficient to support prolonged use or function of our cells. Neurons in the brain can survive only three to six minutes without oxygen before they begin to necrose or die; the approximate amount of time a person can be revived from a heart attack without significant brain damage.
So breath is responsible for providing the oxygen necessary for ATP production that drives cell function and survival; it is what sustains life. But the benefits of our breath go far beyond this basic biological need. Yogis have appreciated this far longer than we have, but science and western medicine are catching up!
We know, for example, that slow, deep breathing relieves stress. It stimulates the parasympathetic arm of our nervous system that is responsible for physiological rest and relaxation. Through activation of our vagus nerve, deep breathing decreases our heart rate and blood pressure, relaxes our muscles, and dampens stress hormone production. It also increases attention, including alertness and orientation, and improves task performance. Deep breathing is so effective at improving emotional well-being and focus that it is often used in the the treatment of anxiety, depression, and attention disorders.
We also know that deep breathing is a physical act that increases muscle strength, cardio-respiratory fitness, and pulmonary function. Combined these serve to improve heart and lung output and therefore delivery of oxygen and nutrients to our cells. Even persons suffering from chronic disease can improve their heart and lung function through breath! Mladen Golubic, a physician at Cleveland Clinic's Center for Integrative Medicine, notes the profound impact intentional breathing has on his patients' health: "You can influence asthma; you can influence chronic obstructive pulmonary disease; you can influence heart failure."
Also fascinating to me is data from a recent Harvard Medical School study that shows deep breathing changes our cells' gene expression patterns, the control of when and where proteins get made. Breath-induced rest and relaxation turned on genes that control energy metabolism and cell-longevity (think anti-aging) and turned off genes involved in inflammation and stress signaling. In short, a few deep breaths will increase your cells' energy production, lengthening their lifespan and fitness, and dampen inflammatory and stress pathways in your body.
The last biological quality of breath I'd like to mention is the impact it has on our mitochondria, the tiny cellular organelles that are the site/machinery of ATP synthesis. Mitochondria are our cells' powerhouses (or generators for those of us living through winter in the northeast right now), and mitochondrial heath dictates our tissues' health. In fact, much of what we think of as natural age-related decline is, in fact, related to diminished mitochondrial function: changes in cognition and memory, muscle strength, fatigue... even susceptibility to cancer. But guess what? You can slow or even reverse these processes by being active and incorporating breath work into your life. Studies show that even a single session of exercise or deep breathing will increase the number of mitochondria in your cells and their ability to produce ATP - particularly in your muscles and neurons. So whether you enjoy walking, dancing, gardening, or even chair yoga, activity and the practice of breath will make you stronger, healthier, and wiser for years to come.
So I encourage you to love your breath a little more today and to embrace all the ways in which it promotes your well-being. I even suggest you try a hot yoga class if you've never taken one before. Yoga is cardiovascular, it is cleansing, it aids in balance and strength; but more than anything it is a quiet opportunity for you to breathe. To focus on what matters most in your life: love. self. others. And as you breathe in on your mat just think for a moment of the beautiful biology that sustains you, and as you breathe out, feel the release of your tensions and a deep sense of gratitude. Namaste.