In our normal bodily positions like standing or sitting, the head is above the heart. Pumping the blood from the heart up to the head requires fighting the effects of gravity, so blood pressure in the head is higher than other parts of the body.
When we adjust the position of the body, as we often do in yoga practice, the head sometimes goes below the heart. When this happens, gravity pulls blood into the head, raising the blood pressure. Our body adjusts by decreasing the blood pressure in the head to protect the brain and face. This effect can be both positive and negative depending on our health and our bodies' ability to adjust the pressure.
If we are healthy, the shifting of the blood pressure up and down can be beneficial, teaching our systems how to respond to changing conditions. This is why healthy people should put the head below the heart.
If we have high blood pressure we must be very careful. Whenever the head goes below the heart, it is possible that the blood pressure will get dangerously high before the body responds. Or the body may not respond effectively and let the blood pressure stay too high for too long. So those of us with high blood pressure should take care when putting the head below the heart.
We can do gentle "inversions" by bringing the head even with the heart or only slightly below. This can be done in forward folding positions and kneeling positions like Half Tortoise or Child's Pose.
One of the main ways that we breathe is with our chest. The muscles between the ribs cause the ribcage to expand and lift up, drawing air into the lungs. This causes the abdominal muscles to become long as they are pulled by the upward motion of the ribs. The abdominal muscles must be relaxed for the ribs to lift fully.
Our feet are where the body contacts the floor/earth. Every ounce of our body's weight goes through them with each step, whether we have a light step or plod heavily. So they are vitally important to our physical health. Poorly functioning feet lead to a poorly functioning body much the same way that damaged wheels make a poorly functioning car.
We have all heard of "flat feet," where the inside arch of the foot collapses toward the floor, often creating painful repercussions in the ankle, knee, hip and even back. This condition commonly refers to just one of the arches of the foot---of which there are four---the medial longitudinal arch (labeled above, #1). That is a fancy way of saying the lengthwise (longitudinal) arch on the inside (medial) of the foot. Most of us just know it as the "arch."
This well-known arch of the foot is not structured like a weight-bearing arch. It is built more like a spring that bends when we put weight on it and bounces back as we release. This is how some of the "spring in our step" occurs, as the arch recoils. This arch can be bolstered with muscular strength, like lifting the inner ankles up and pulling the ball of the foot toward the heel.
The second major arch of the foot is the lateral longitudinal arch, which means the lengthwise (longitudinal) arch on the outside (lateral) of the foot. It is labeled in the picture above with #2. This arch goes from the heel area toward the pinky toe. It is a very stable arch, with bone structure like a traditional weight-bearing arch. Due to its structure, this arch rarely collapses or gives us trouble, so we don't even realize it's there.
The third arch of the foot goes across the foot, so it is called a transverse arch. Since it is closer to the ankle, it is called the proximal (near to the body) transverse arch, labeled #3 in the picture above. This arch, like #2 above, is structurally very stable and rarely collapses or gives us trouble. This arch is also called the anterior (forward) transverse arch.
The fourth arch of the foot is sometimes not considered an arch at all because it is not formed by arch-like bony structures. Instead, this arch is made of soft tissues like ligaments, muscles and fascia, stretching from the big toe to the baby toe. It is called the distal (far from the body) transverse arch, labeled #4 in the picture above. Since it is not a bony-structured arch, this often gives us trouble due to weakness and under-use, especially since we wear shoes that decrease our body's need to access it. It can be strengthened though simple exercises like making fists with the toes.
Try standing with bare feet. Shift your weight around your feet, from front to back and side to side. Pay close attention and see if you can feel the arches and structures in your feet. They are important!
Most of us know that our breath functions automatically most of the time. This function---breathing without thinking---is controlled by the autonomic nervous system in one of the oldest parts of our brain: the brain stem, located at the base, where the spinal chord turns into the brain.
Most of us also know that we can control our breath consciously, choosing the speed at which we breathe and even stopping it altogether, for a short while at least. This conscious control of our breath is done by the somatic nervous system, the part that controls voluntary functions like walking, writing or playing baseball. It is located on the surface of the brain at the very back of the frontal lobe, in a place called the motor cortex.
Whenever we consciously control our breathing, the motor cortex overrides the brain stem. This process takes a lot of effort from the brain, which is why it has the effect of focusing us. As an experiment, try to control your breath while doing a math problem in your head. It is difficult. When we consciously control the breath, the brain becomes still.
This phenomenon is one of the key principles of pranayama (breath control) and even the most simple breathing exercises. Even for a true beginner, counting the breath or trying to control it at all calms the mind and leaves them feeling very focused.
Uddiyana and Nauli are traditional yogic practices. They date back more than 500 years to at least the Hatha Pradipika.
To do Uddiyana, one holds the breath out and then expands the ribcage as if inhaling. What results is a vacuum in the abdomen which sucks the belly, intestines and organs up. Uddiyana means 'flying up.' "This practice is called Uddiyana because the diaphragm is made to fly up from its original position and held very high in the thoracic cavity." (Yoga Mimamsa, Vol. 1, Oct. 1924)
In the early 1920s, Swami Kuvalayananda began a school and laboratory, using modern scientific equipment to test traditional yogic practices and publish the results. His newsletter is Yoga Mimamsa, which started in 1924 and continues today. The first edition was dedicated to the study of Uddiyana.
They performed two ground-breaking studies, one involving early X-Ray technology to view the intestines, and the other measuring the internal pressure of the abdominal cavity during Uddiyana. "This exercise has been studied under the X-Ray. Very interesting and valuable data have been collected. Two X-Ray experiments are published...and an article discussing the therapeutic value of this Yogic practice is included..." (ibid.)
The pictures above are from the 1960s, when Dr. Gouri Shankar Mukerji performed a similar experiment. These pictures are much clearer than the ones from 1924, which is why we post them here. The x-rays from 1924 are cloudy and difficult to discern. In the above pictures, one can clearly see that Uddiyana pulls the intestines and organs up into the thoracic cavity.
The second test measured pressure in the intestines and rectum during the practice. They found that internal pressure is reduced, creating a partial vacuum. "As soon as the muscles were moved for Nauli, the mercury fell through 40 mm. indicating a clear partial vacuum." (ibid.) The discovery of this vacuum was significant, since scientists of the time hypothesized that Nauli reversed the peristaltic movement of the intestines, which would be detrimental to health. The discovery of the partial vacuum refuted this idea. Kulvalayananda named his discovery the "Madhavadasa Vacuum," after his esteemed teacher.
The Sit-Up that we often do in this lineage of yoga - starting flat on the back with the arms overhead and legs straight, then sitting all the way up and touching the head to the knees - is more complex than it looks. It requires strength in two major muscle groups: those of the abdomen, specifically the rectus abdominis (6-pack) and the psoas, which crosses the hips.
INHALE OR EXHALE
The question often arises, "should I inhale or exhale while doing a sit-up?" The answer is clear: You should exhale.
In a recent New York Times article about the remarkable abs of USA olympian Adam Rippon, Rippon's trainer Steve Zimm said, "Breathing is everything when it comes to abs. If you want ripped abs, you need to allow them to contract. Before every move, breathe out. Pull your belly button into the spine and continue breathing out as you’re contracting, so your abdominal wall is sinking into you."
Not surprisingly, Bishnu Ghosh agrees. In his book Yoga Cure he instructs: "Start from lying position with arms stretched beyond your head, exhale and hold your breath and then raise your upper body..."
Our recent blog about the myth of oxygenation got a big response. Lots of surprise, some disbelief and a lot of requests for more information. Specifically, if deep breathing does not have a positive impact on our oxygen levels, why do we do it?
There are three huge benefits to practices of breathing: activating and balancing the muscles of breathing, which in turn affects the nervous system; balancing the hemispheres of the brain through the nostrils; and awareness and minor control of the breath-regulating parts of the brain.
THE MUSCLES & THE NERVOUS SYSTEM
You may have heard that some people are belly breathers and some are chest breathers. Most of us have at least a slight imbalance between the abdomen and chest, while others have extreme imbalance. This doesn’t necessarily have an effect on our ability to get oxygen, but it does have an impact on our nervous system.
Generally speaking, abdominal breathing that uses the diaphragm and relaxes the abdominal muscles stimulates the parasympathetic nervous system. The opposite is true for chest breathing that uses the intercostal muscles. This stimulates the sympathetic nervous system.
Neither of these is a problem until our breathing patterns become imbalanced and we breathe primarily through only one of the systems. When years or decades go by, one part of the nervous system chronically gets stimulated while the other gets suppressed. Belly breathers will be more relaxed, sleep more, have lower body temperature, be more lethargic. Chest breathers will be more energetic, more stressed, warmer, sleep less.
It is vital for progress in yoga to have balance in the nervous systems. So the first step of breathing practice is to learn to use both parts of the breath, strengthening the muscles and evening the nervous systems.
The olfactory nerves in the nose go straight to the brain. They have the most direct connection to the brain of any of the senses, so their stimulation through the nostrils is potent. The breathing practice of Alternate Nostril, which goes by many names, is one of the oldest yogic techniques. By alternating which nostril we breathe into, we vary the hemisphere of the brain that we stimulate. This has a further effect on the sympathetic and parasympathetic nervous systems, and goes even further to balancing the dual nature of the body and mind.
PARTS OF THE BRAIN
The breath is controlled by the brain stem, the oldest part of our brain. Most of the time, we breathe with no conscious thought. But the newer parts of the brain, specifically the cortex, have the ability to override the brain stem to some extent, especially with practice. This awareness and control is very difficult and not appropriate for beginning practitioners, but it is the ultimate reason for breathing practices. Gradually we come to realize the true nature of the breath, which brings us closer to realizing the true nature of the self. (Apologies for the abstract yogi talk, but I don’t know of a clearer way to put it.)
So breathing is powerful. If we use it correctly it has the ability to balance our nervous system, the hemispheres of the brain, and even put us in touch with some deep and essential parts of our being. To me, this is all way more exciting than oxygenating the body!!
How many times have you heard a yoga teacher tell you that deep breathing "oxygenates the blood?"
It isn't true. At the very least it is misleading.
Our nervous system forces us to breathe at the necessary rate to fully oxygenate our blood at all times. This is true when we're resting as well as when we're running a marathon. The body's oxygen requirements are different depending on our activity, and the nervous system automatically adjusts to oxygenate the blood fully. Normal blood oxygenation is 95-100%.
When we are at rest, we breathe slower since the body's oxygen demands are less. Breathing more or deeper while the body is at rest does not "oxygenate" the blood. It hyper-ventilates, which is just a way of saying breathing (ventilating) more than necessary.
Anytime we breathe more than the body requires, the big change we are causing is the removal of carbon dioxide, one of the body's metabolic wastes. Hyperventilation removes more carbon dioxide than the body produces, and this leads to a whole host of physiological effects. Most significantly, the blood vessels in the brain constrict, limiting blood flow to the brain. This makes us light-headed.
So that light-headed feeling you get when breathing deeply isn't energization or "oxygenation," but constricted blood vessels in the brain. Your brain is actually getting less oxygen than if you were to breathe normally!
The muscles of the body most often use concentric contraction to create movement. This means that a muscle shortens as it contracts, pulling the skeleton into position. For example, in backward bends the erectors of the back contract and shorten, and the spine bends backward. In forward bends, the rectus abdominis (6-pack) shortens and contracts to bend the spine forward. This type of contraction is also how we walk, run, stand up and do many other basic functions.
So why are our legs so sore after poses like Standing Bow, Standing Separate Arms Balancing Stick (pictured) or Standing Splits?
These poses require eccentric contraction, meaning that a muscle lengthens as it contracts. The hamstrings of the standing leg eccentrically contract in these balancing postures, bearing the weight of the upper body as we tilt forward on the hip. The hamstrings must contract to keep the body from collapsing forward. It is a common misunderstanding that the standing leg hamstrings should relax in Standing Bow or the others. This couldn’t be farther from the truth; the hamstrings actually do most of the work.
This complexity—asking the hamstrings to lengthen even as they hold the weight (eccentric contraction)—makes the muscles a lot more sore than concentric contraction.
Scott & Ida are Yoga Acharyas (Masters of Yoga). They are the head teachers of Ghosh Yoga. This blog is about their experience with yoga practice, study and teaching.
- Understanding Chair Posture
- 5 Reasons To Backbend
- Lock the Knee History
- Why Teaching Is Not a Personal Practice
- The 113 Postures of Ghosh Yoga
- When You Take a Class, Take the Class
- Should We Be Teaching Advanced Postures in a Beginning Class?
- The Yogi Becomes Invisible
- Bow Pose (Dhanurasana)
- The Oxygenation Myth