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Tuesday, June 25, 2013


 While staying in Chang Mai, I encountered beautiful, intelligent beings living in captivity in two separate and very different circumstances. The first was at the Chang Mai Women's prison and the second was at an elephant riding attraction. It may not be completely correct to compare humans and elephants living in captivity, but the two experiences evoked similar emotions and stimulated significant consideration and contemplation.

I visited the women's prison on my first day in Chang Mai, and really my first true day in Thailand. I was still adjusting to the climate and was fairly jet lagged, so I was exploring the city in a bit of a fog. I read in Lonely Planet that the prison has a progressive vocational training program that aids in the transition from prison to freedom. Before release, inmates are taught Thai massage from a prestigious local school along with other handicraft skills. The women then perform massages for tourists and sell their crafts at a very pleasant facility across the street from the prison. They receive a portion of the proceeds, which they can save so they are not completely broke upon their release.

When I arrived at the massage and craft center, I walked through a garden to a reception area and made a massage reservation with the female prison guard at the front desk. There was a two hour wait for a massage, so I sat at a table in the garden and ordered lunch. Pad Thai and a coconut smoothie were delivered promptly and as I sat enjoying my lunch, I also enjoyed the many native plants and sculptures that adorned the garden. The ground was covered in decorative brick work and above me was a thick canopy of green trees with orchids growing on their trunks. This setting surely did not feel like a prison. The only reminders that I was on the property of a prison were signs with pretty script spelling out "Prison Products," where there were soaps, change purses, and small dolls on display for sale, and of course the prison guards.

I was impressed even further when my number for a massage came up. I left my shoes outside and slipped on complimentary slippers. Once I was shoeless, I was led inside by the guard and given a set of scrubs to change in to in the bathroom. This was fairly comical because I was given size XXXL bottoms, but I tied them on tight and was led to a sitting area to wait to have my feet washed. The prison guard went back to attend to another guest outside and I was now in the care of the prisoners.

All of the prisoners were young and pretty with kind eyes and loads of patience. The first girl I interacted with simply washed my feet and did a pretty good job disguising her disapproval of the state of my feet and legs (walking around a city in flip flops is messy!); I was a little embarrassed, however. I sat back down in the waiting area for hardly a moment when a girl with a warm childlike face asked if my feet had been washed already and then led me to her massage table. When I laid down, she looked at my feet and asked again if my feet had been washed. Apparently, they still didn't look clean. After skeptically accepting that this was as clean as my feet would get, she began her massage.

As I looked around the room, I noticed that the sequence of the massage was the same on each table but that each girl had a personal style. My masseuse was not rough, perhaps overly gentle, and as the massage proceeded, she would catch my eye and smile shyly. As I lay there enjoying being stretched and pulled, popped and prodded, I could only think about what crime my masseuse could possibly have committed. I was too shy to ask, so I will never know, but she seemed too gentle and kind to have done anything very punishable. 

I left feeling happy and warm and the feeling lingered as I walked through the evening streets watching the day's business wind down. The post massage glow did not fade until much later: probably after stuffing myself sick at the vegetarian buffet at my guest house. And as it did, I began to wonder if I felt like I had taken advantage of the girls at the prison massage parlor or if I had paid them a service by visiting the facility. Months later, I still don't know. I don't know exactly what was the girls' cut of the minuscule fee I paid. And, how many hours did they work? How many days a week? Did they enjoy it? Did it feel like slavery to them? Being too timid to ask, I won't know. But, I can imagine how I would feel in their circumstances. 

Two days later, I visited an elephant camp on a full day tour I had booked through a tour company a block from my guesthouse. The elephant riding was the first activity of the day and I was a little apprehensive about what I might witness. These poor beings had just as little say in performing their services as the women prisoners. Elephants in Thailand are revered, but currently are in a bad spot. They had been in high demand during the height of the logging boom. But as the number of trees dwindled, the king proclaimed a moratorium on logging in Thailand and the elephants found themselves unemployed. Eating several tons of food does not make an animal a likely or welcome pet, so the elephants soon found themselves homeless, as well. Tourism in Thailand is the only thing that supplies enough income to support elephants these days, and many elephant camps that give tourists elephant rides and the opportunity to care for elephants have sprung up throughout the country. The camps have varying reputations, with some taking very good care of the animals and others being rather cruel. 

The camp I visited this day fell somewhere in the middle, but closer the humane side than the cruel. The mahouts, the men that trained the elephants, seemed well connected with the animals and were skilled in directing them. The mahout that led the elephant I rode invited me out of the tourist seat and instructed me to sit on the elephants neck. He failed to give me any further instructions, however, so I had a bumpy ride (I later learned that it is important to sit as close to the head as possible to have a stable ride). As we rode along a quaint forest trail, I fed the elephant a banana each time he reached his trunk back to me. Occasionally we would stop at little shops on stilts so that I could purchase another bunch of bananas for 20 Baht (less than a dollar), and we would be on our way - walking along the trail with me hanging on for dear life, the elephant munching bunches of bananas and easefully ambling forward, the mahout snapping pictures from the ground as he walked beside us and occasionally giving the elephant an order.

Most of the ride was very pleasant, only once was I forced to consider the well being of the elephants. The elephants wear chains around their ankles that attach them to trees or buildings. Someone later told me that the elephants are fully able to break their chains whenever they wish, but that they stay because they are satisfied; they have food and water and are cleaned up after and given daily exercise.  That seems reasonable, but after noticing an elephant chained to a tree quietly swaying back and forth with a bored, crazed look in its eyes, I had to wonder if the elephants were happy and fulfilled. They are so smart and soulful, surely walking in large circles and begging for bananas all day cannot be enough. 

It occurred to me that as I enjoyed a massage and a delightful ride through the forest, the humans and elephants involved were enduring indignity and simply smiling and performing a service because they had no other choice. Would I do it again? Would I go back to these places and have another $7 massage from a prisoner or $10 elephant ride? I can't say. But, I would encourage others to visit and come up with their own conclusions. 

                              The elephant that carried me through the woods.
                                 Another captive elephant walking up to meet its next rider.
The mahout who has trained and cared for the elephant I rode.
Another mahout with his elephant. 

Wednesday, June 12, 2013

Your Water Footprint is Bigger Than You Think

Before I went out of town for summer instructor training, a friend and fellow Air Force wife asked me if I would be interested in volunteering at an upcoming event she was organizing. Amanda is the education coordinator for the 4H program in Valdosta and visits county classrooms delivering environmental and agricultural lessons and organizes camps and workshops at the cooperative extension (yes, I am very envious of her job...). The upcoming event was a "Water Day," with educational presentations and activities relating to water in the morning and water games such as relay races and a slip-n'-slide in the afternoon. Obviously, Amanda did not have to ask twice for my participation.

In thinking about what I would teach on Water Day, I considered several lessons I had prepared and taught previously, but each was focused on a particular (non-Georgian) location. I decided to write a new lesson based on topics drawn from several previous water conservation lessons that I had taught. Truly, this lesson was born from one tiny aspect of a lesson prepared by the Albuquerque Water Utility that I used in my middle school classroom. That lesson was primarily focused on how much water is involved in producing electricity for Albuquerque, but they included 3 or 4 slides containing the amount of water that goes into the production of some common products like jeans and sodas. These amounts are staggering and surprising, enough so that it makes one wonder about other products and may even inspire lifestyle changes. And so, I wrote this lesson expanding on the concept of a "Water Footprint."

Lesson Plan: Your Water Footprint is Bigger Than You Think
Grades: 6-9
Time: 45 minutes

Objective: Educate students about the "hidden" water used in the production and transportation of products and food and to inspire consideration of alternative choices that could decrease the size of an individual's water footprint.

Materials: Apple, Knife, 1 gallon of drinking water, printed slides and handouts (Water Footprint Powerpoint)


  1. Start off with the well-known "apple as the world" activity to demonstrate that despite the earth being 75% water, water (and land) resources are limited. Cut the apple into quarters, one quarter represents the land component of earth. Cut the quarter representing land in half, put one half to the side - this represents deserts, mountains, tundra, swamps and other areas that are uninhabitable. The other 1/8 sized piece is land that people inhabit. Cut this piece into fourths, making 1/32 sized sections and set three aside. These three 1/32 pieces represent places people live but are too steep, rocky, cold, wet, dry, or have poor soil, or are covered with cement and development and therefore cannot produce food. The single 1/32 sized remaining piece is land that produces food. So, it is obvious land is scarce, but 3/4 of earth is water! How can water be scarce? Well, only 3% of all that water is freshwater. Of that 3%, 2/3 is frozen... so only 1% of all the water on Earth is available for drinking and food production.
  2. Discuss desalination with students. Some people may point out that salt can be removed from water and therefore we cannot run out of water. But, desalination requires large amounts of energy, so one scarce resource (water) is being produced by using up another scarce resource (energy), making the process an unsustainable solution to water scarcity. Additionally, desalination plants are on coasts and the water must be transported inland, using up even more energy.
  3. Fresh water is scarce - availability is shrinking, demand per person is growing, and the human population is really growing! The consumption of water by humanity is no longer sustainable and places around the world are suffering; rivers are running dry, water levels in lakes are dropping, and species are becoming endangered and extinct.
  4. So, how much water is each of us really using? It doesn't feel like very much because most of the water we use is "hidden." As humans, we need to drink 8 glasses of water a day, but we actually consume 25,600 glasses per day. This equates to 583,000 gallons per year! Pass around the gallon of drinking water for students to feel and see how much water a gallon really is. It is difficult to visualize and grasp how much water 583,000 gallons really is. Try to picture thousands of gallon containers stacked up. How much space would they take up? Does it feel like you use that much water? No! That is because 95% of water consumed is "hidden water."
  5. Where is all this hidden water? There are two categories of hidden water: your direct water footprint and your indirect footprint. The direct footprint is much easier to see and understand. This is water that you use directly, like flushing the toilet, washing dishes, taking a shower, watering the lawn. Have students brainstorm components of their direct footprint. 
  6. The indirect footprint is more difficult to see and understand; this includes all the water involved in manufacturing, producing, packaging, and transporting our food and goods. Have students brainstorm specific sources of indirect water usage (watering crops, extracting fuel, producing vehicles and machines, producing pesticides and fertilizers, etc.). These things add up... to big numbers.
  7. Show slides (product printed on one side and the water footprint printed on the reverse side) of foods and goods and have students guess how much water went into making them. After doing a couple and they start to get the hang of it, they can use thumbs up, thumbs to the side, or thumbs down to vote if the product will have a larger or smaller water footprint than the previous product. See examples below (more slides are included in the full slide show):


  8. Students will likely notice a pattern as your go through these slides. But as you reach the last slide, ask students if they notices things that products with large water footprints have in common. Animal products and processed products generally have larger footprints. Discuss all the steps that go into producing processed foods. Ask which will have a larger footprint, corn chips or corn? Animal products use more water because they are higher on the food chain. They include the water foot prints of each of the organisms that they consume. So which would have a larger water footprint, a carnivore or an herbivore? A carnivore or an omnivore? A plant or a plant-eater? If students are not seeing these patterns on their own, show them this graph that I made to help students visualize the pattern: Water Foot Print Bar Graph
  9. Calculating an individuals water foot print is actually quite complicated and uses computer models (think lots of calculus). You can use these models to calculate your water footprint using the quick or extended water footprint calculator provided provided by You can also do a quick calculation of the water you use in the bathroom in an average day (see handout from slideshow). Have students calculate how much water each of them uses in the bathroom each day and then have a student collect everyone's totals and add them up to find out how much the class uses in the bathroom in one day! It will be a lot. 
  10. Now it is time to consider how to reduce our water footprint and use fresh water more sustainably. Have students get into groups to work together to brainstorm ideas for reducing their direct and indirect water footprints. Remind students to come up with realistic ideas; it is probably not realistic to suggest replacing your home toilets (expensive!), but it is feasible to replace shower heads!
  11. Bring the class back together and have each group read their two best ideas. Discuss ideas as your go around. Some ideas I have heard include: turn off water when brushing teeth, xeriscaping, don't water lawn during the day, turn off the water when washing dishes, use a dishwasher, make sure dishwasher is full, take shorter showers, eat local food, eat more vegetables, have hens to for eggs, keep goats or cows for milk, hunt for your own meat, eat vegetarian or vegan, eat organic, shop at thrift stores, shop less, use products and foods that have smaller water footprints, use local products (soap, honey, jams from farmers' market)
  12. Debrief: Was it difficult to come up with ideas to reduce your footprint? Was it harder to come up with direct or indirect water saving ideas? Was there anything you knew would reduce your footprint, but you don't want to do (take shorter showers, drink tea instead of coffee)? Are some uses of water more important/better than others? Will you actually carry out any of the ideas you came up with? Should products be labeled with their water footprints? 
Extension: Students can write a detailed action plan to reduce the water footprint of their school or camp. The action plan can be presented to the principal or camp director and suggested changes can be implemented and enforced by students.

This lesson went really well with the group I presented it to. The students were shocked by how much water was used in the production of food and manufactured goods and appeared really interested in minimizing the amount of freshwater they consume. We had an interesting discussion about actions we could take, but don't really want to - like taking shorter showers; sometimes doing good takes sacrifice. 

I also came to some realizations about eating and culture in the south. Despite our conversations about trophic levels and the water footprints of animal products, not a single group of students wrote down vegetarianism as a means to reduce their indirect footprint. Amanda suggested this idea to a group when I was close enough to overhear, and their response was as comical as it was disturbing. Overall, the students were shocked and appalled at the suggestion and wondered aloud how or why anyone would be vegetarian. I told them that I am a vegetarian and they looked at me like an alien and asked how I ever feel full. The most vocal girl in the group declared that a meal is not a meal if it does not have meat, that she eats meat at every single meal, and that salads are only side dishes. The truth is that I was just as horrified by her diet as she was by mine. When I relayed this story to Jamie, he was unsurprised. He also noted how many overweight people there are in our new town.. 

I feel lucky to have had this opportunity to interact with local students and they really were a great bunch. On the actually "water day," it was pouring and all games had to played inside in the barn. The slip-n'-slide, water guns, and water balloons were left in the closet. Despite this, the kids maintained a really positive attitude, participated actively, and seemed to have a blast playing games inside. I really hope I get to work with this group again sometime. Maybe eventually I will convert an avid Georgian meat consumer into an environmental vegetarian...

Tuesday, June 11, 2013

Breathe Deep: Yoga Meets Science

In attending years of yoga classes, I have heard uncountable descriptions of how yoga benefits the body and mind. I firmly believe that yoga does have many positive effects on the practitioner, but sometimes a yoga teacher will spout a benefit that just does not seem realistic. Claims surrounding one practice in particular, pranayama or breath practices, drove me crazy for years. At the beginning (and end) of most yoga classes, the teacher will instruct some form of breathing practice to help the students get centered and grounded and more able to focus on the class. The teacher will often list the benefits of the practice as he or she instructs, and these can include a huge variety of claims, but the one that I heard most often and most often questioned was "increased oxygenation of the blood." Based on my understanding of biology and human physiology, this just did not seem true. Hearing this in class disturbed me and stole my focus away from the practice at hand. As a result, pranayama would cause more dialogue in my mind instead of less. At the suggestion of my teacher, I finally researched the topic more thoroughly and wrote an essay on the true and fictional effects of pranayama on the body and mind.

“What really happens when we breathe deeply?”

Maggi Mars Brisbin - RYT-200

Pranayama is defined by the meanings of the two Sanskrit roots that make up the word: prana and ayama; prana means respiration, breath, life-force, or animating energy and ayama means to lengthen, stretch, or extend. Taking the definitions of these two words together, pranayama means to lengthen, stretch, and extend the breath or life-force (Dharmashakti, F-18). In Patanjali’s Yoga Sutras, the primary text of yoga, pranayama is only mentioned in sutras 2.49-2.53. In these sutras, Patanjali states that pranayama is the control of the movement of the inhalations and exhalations, that “modifications of the life-breath are external, internal, or stationary” and are “regulated by space, time, and number and are either long or short.” Patanjali advises that if pranayama is practiced and mastered, the “veil over the inner light is destroyed, and the mind becomes fit for concentration (Carrer, 369-370).” Despite the limited amount of information provided by Patanjali, there has been a large repertoire of pranayama practices created to provide an array of physical, mental, and emotional benefits to the practitioner. Several common pranayama practices include Deergha Swasam, Nadi Suddhi, and Kapalabhati and their many declared benefits include, but are not limited to, oxygenation and purification of the blood, improved resistance to infections, calming of the central nervous system, stimulation of the parasympathetic nervous system, relaxation of skeletal muscles, drawing of the mind inward, preparation to enter a meditative state, and improved vitality (Dharmashakti, F-18). Many of these effects are challenging to measure and quantify and it can be difficult for a skeptical practitioner to accept them without scientific experimentation and explanation. As it turns out, some of the purported benefits of pranayama have been medically investigated and validated, while others lack scientific evidence.

In order to understand how the benefits of pranayama, particularly the oxygenation and purification of blood, may or may not occur in the body, it is necessary to examine the physiology of breathing. The respiratory system includes the respiratory airways leading into and out of the lungs and the lungs. Air entering the nasal cavities proceeds to the pharynx, trachea, primary bronchi, secondary bronchi, tertiary bronchi, bronchioles, and then the alveoli of the lungs, which are the site of gas exchange. Gas exchange, the primary function of the respiratory system, is executed through the process of diffusion and therefore relies completely on concentration gradients. At sea level, air pressure is 1atm or 760mm Hg. The air is composed of a mix of gases, mostly oxygen, nitrogen, and carbon dioxide, and the total air pressure is therefore composed of the partial pressures of these individual gas components. In the ambient air, the partial pressure of oxygen (PO2) is about 160 mm Hg or 21% of the total pressure. Inside the alveoli of a normal, resting human being, the partial pressure of oxygen is about 104mm Hg and the partial pressure of CO2 (PCO2) is 40mmHg. Blood returning to the lungs from the body has a PO2 of 40mmHg and a PCO2 of 45mmHg, so there is a large concentration difference between the blood and the air inside the alveoli. Subsequently, oxygen diffuses into the blood and carbon dioxide diffuses out of the blood (

The PO2 gradient described is significant because it necessitates that the blood entering the alveolar capillaries will leave with 100% oxygen saturation (PO2 100mmHg and PCO2 40mmHg). The blood is then pumped through the heart (no gas exchange) and into systemic circulation. Body cells are low in oxygen and high in carbon dioxide from the energy producing process of cellular respiration. Following the concentration gradient, oxygen diffuses into body cells and carbon dioxide diffuses into the blood, where it binds with hemoglobin or is transported as bicarbonate ions. When the blood returns to the alveolar capillaries, it again has a PO2  40mmHg and PCO2 45mmHg, allowing for gas exchange between the alveoli and alveolar capillaries once more. In order for gas exchange to continue, the concentration gradient must be maintained; this is accomplished by breathing and continuously bringing fresh air into the alveoli (

            To aid in understanding the effects of PO2 on the oxygen saturation of hemoglobin, the oxygen-hemoglobin dissociation (saturation) curve visually describes the oxygen saturation of hemoglobin along varying partial pressures of oxygen and different conditions. Under normal resting conditions within the body, hemoglobin is near oxygen saturation (75-80%) at a relatively low partial pressure of oxygen (40mmHg). Keeping resting conditions in the body, the saturation of hemoglobin will increase with increasing PO2 until it reaches 100% saturation; hemoglobin is 97% saturated at PO2 of 60mmHg and 100% saturated at PO2 of about 100mmHg. Remember that the PO2 in the alveoli of the lungs is 104mmHg, so as blood leaves the lungs, the hemoglobin is 100% saturated with oxygen.

Body cells generally have low levels of oxygen (PO2 40mmHg), meaning about 20-25% of hemoglobin molecules passing by will give up their bound oxygen to them. This is extremely adaptive as it allows more oxygen to be released where it is needed if a person becomes more active. Active tissue may have a PO2 much lower than 40mmHg and blood will quickly offload oxygen to active tissue. In addition to a more dramatic PO2 concentration gradient, active cells with increased cellular respiration produce heat along with metabolic waste products such as carbon dioxide. Carbon dioxide undergoes a reaction in the blood that produces free hydrogen ions and lowers the pH. Increased temperature and lowered pH both decrease the affinity of hemoglobin towards oxygen, allowing more oxygen to be released from the hemoglobin molecules. Finally, active cells will produce a substance called 2,3-diphosphoglycerate, which changes the shape of the hemoglobin molecule causing oxygen to be released more readily. Active cells therefore change their immediate environment – increase temperature, increase carbon dioxide levels, decrease pH, and increase 2,3-diphosphogylcerate – to assure that oxygen is delivered exactly it is most needed in the body (

            Pranayama practices that involve long, deep breathing are said to deliver more oxygen to the body and to detoxify the blood. With an understanding of hemoglobin saturation in the body, it is clear that breathing more deeply cannot increase the amount of oxygen in the blood nor would it remove carbon dioxide more quickly. These claims surrounding deep breathing are most likely based on an understanding of respiratory volumes and capacities. Tidal volume (TV) refers to the volume of air moving in and out of the lungs during normal, resting breath and is generally 0.5L in adults. Inspiratory reserve volume (IRV) is the volume of air that can be inhaled after a normal breath and is approximately 2.3-3.2L in adults. Expiratory reserve volume (ERV) is the volume of air that is able to be forcefully expelled after a normal exhalation and is about 1.0-2.0L in adults. The residual volume (RV) is the volume of air that remains in the respiratory system after the ERV has been expelled. The RV, generally 1.2L, is the air that cannot be purged from the respiratory system. The inspiratory capacity (IC) is the TV+IRV or the maximum amount of air that can be inhaled. The functional residual capacity (FRC) is all of the air that is not expelled during normal breathing (ERV+RV). The vital capacity (VC) is the total volume of air that an individual is capable of moving in and out of the lungs (TV+IRV+ERV). In adults, there is also about 150mL of dead space or dead air, which is air that is moved in and out during breathing but does not reach a gas exchange surface and does not participate in gas exchange. While we are breathing normally at rest, we are moving only the tidal volume in and out of the respiratory system. Because of the reserve volume, residual volume, and dead space, there is mixing of inhaled and exhaled air. This is the reason that the partial pressure of oxygen in the alveoli during normal, resting breathing is only 104mmHg instead of equaling the partial pressure of oxygen in the surrounding air, which is 160mmHg. If a person is utilizing the full vital capacity of the lungs while breathing deep slow breaths, they may be able to increase the partial pressure of oxygen in the alveoli by more completely expelling air from the lungs and therefore inhaling a larger amount of fresh air with less mixing. This, however, will not actually provide more oxygen to the body, since hemoglobin is already 100% saturated when the partial pressure of oxygen in the alveoli is only 60mmHg (

             In an experiment illustrating the noneffect of deep breathing on blood oxygenation, Pratap et al. (1978) drew arterial blood from ten volunteers proficient in pranayama breathing techniques before and immediately following pranayama practices. The levels of carbon dioxide and oxygen in the blood were measured and compared; no significant changes in arterial blood gases were found after pranayama breathing practices. Pratap et al. concluded that a neural, rather than chemical, mechanism must be responsible for the reported benefits of pranayama (Pratap et al. 1978).

            The action of breathing consciously and unconsciously is controlled by skeletal muscles regulated by the phrenic nerves, several control centers in the brain, and chemoreceptors and mechanoreceptors in the body. The physical movements of breathing are performed by skeletal muscles. During a normal inhalation, the external intercostals and the diaphragm contact. Contraction of the external intercostals elevates the ribs and sternum and increases the front to back dimension of the thoracic cavity. Contraction of the diaphragm pulls the diaphragm downwards, which increases the vertical dimensions of the thoracic cavity. The contraction of these muscles increases the volume of the lungs by about 0.5L and decreases the pulmonary pressure by 1mmHg, which causes air to enter the lungs. During exhalation, the external intercostals and diaphragm are relaxed and the volume of the thoracic cavity returns to the pre-inspiratory volume, which increases pressure in the lungs and forces air out. The external intercostals and the diaphragm are innervated by the phrenic nerves that originate mostly from the 4th cervical nerve, but also from the 3rd and 5th cervical nerves. The phrenic nerves, with sole motor control of the diaphragm, contain motor, sensory, and sympathetic nerve fibers and are influenced by the respiratory center in the medulla (

The medulla’s respiratory center is divided into the ventral and dorsal group; the dorsal group or inspiratory center is composed of “I neurons” that stimulate the phrenic nerves that bring about contraction of the external intercostals and diaphragm. The dorsal group also contains “E neurons” which inhibit the “I neurons” and allow the external intercostals and diaphragm to relax and therefore allows for exhalation. The ventral group, or the expiratory center, stimulates phrenic nerves and then intercostal nerves that innervate the internal intercostals and abdominals.  The expiratory center produces a “forced exhalation.” There are also two respiratory centers in the Pons: the pneumotaxic center and the apneustic center. The pneumotaxic center slightly inhibits the medulla and causes shorter, shallower, quicker breaths, while the apneustic center stimulates the medulla and causes longer, deeper, slower breaths.  These four centers control normal breathing, but respiratory centers in the hypothalamus can impact breathing based on emotional responses, pain, and sexual arousal and respiratory centers in the cerebral cortex exhibit voluntary control over breathing and can override the medulla during talking, singing, and exercise (

During exercise, there is often an increase in breathing rate and depth. When breathing in this manner, the scalene muscles, the sternocleidomastoid, and the pectorals are recruited to aid the external intercostals and the diaphragm in increasing the volume of the thoracic cavity. These muscles are voluntary and the increased rate and depth of breathing during exercise is due to a conscious awareness of exercise. The cerebral cortex responds to the awareness of increased activity by stimulating the accessory muscles of external respiration and the respiratory center in the medulla. There is a steady state increase in rate and depth, which is gradually altered to match gas exchange needs ( In purposeful deep breathing practices, the cortex is used to override natural resting breath and the muscles recruited for deep breathing during exercise are consciously engaged.

Chemoreceptors in the body respond to chemical changes in the blood and convey signals to the respiratory centers of the brain, which induce changes in breathing rates and depths. The peripheral chemoreceptors in the carotid arteries and the central chemoreceptors in the medulla are very sensitive to the amount of carbon dioxide dissolved in the blood. An increase in carbon dioxide and/or the resulting decrease in pH stimulates the inspiratory center and results in increased ventilation. A severe decrease in oxygen levels in the blood will stimulate increased ventilation, but a moderate decrease in oxygen levels in the blood will not have this effect ( Many people are surprised to learn that the desperate urge to breathe that is experienced during prolonged breath holds is a response to increased carbon dioxide rather than lack of oxygen.

The importance of mechanoreceptors to breathing is seen in the Hering-Breuer Reflex. The Hering-Breuer reflex prevents the over-inflation of the lungs by sending nerve impulses along the vagus nerve to the brain in response to the stimulation of pulmonary stretch receptors in the smooth muscles of the airways. The inspiratory region of the medulla is directly inhibited and the apneustic area of the pons is inhibited, which stops it from stimulating the medulla’s inspiratory area, resulting in exhalation. This neural circuit involves several regions of the central nervous system and utilizes motor and sensory components of the vagus nerve. The lung afferent neurons also send inhibitory projections to the cardiac vagal motor neurons, which send motor fibers to the heart by way of the vagus nerve and cause tonic inhibitory control of heart rate. Therefore, an increase in the Hering-Breuer reflex causes an inhibition of the cardiac vagal motor neurons and an elevation of heart rate. ( This is part of the system that causes an increase in heart rate during inhalation and a decrease in heart rate during exhalation. This normal varying of heart rate is referred to as sinus arrhythmia (Pal et al. 2004). Slow, deep breathing stimulates pulmonary stretch receptors and by initiating the neural loop described by the Hering-Breuer reflex, it is believed that slow, deep breathing tones the vagal nerve, improves autonomic nervous system functions, and shifts the system towards parasympathetic control (Pal et al. 2004, Jerath et al. 2006).

Pal et al. (2004) investigated the effects of pranayama on the autonomic nervous system using several common tests of autonomic function - basal heart rate, heart rate response to standing, the difference in heart rate during inhale and exhale while deep breathing, and the heart rate response to a prolonged Valsalva maneuver – before and after the experiment. In the experiment, 60 volunteers were divided into the slow breathing (n=30) and fast breathing (n=30) groups and the groups were further divided into test and control groups. In the slow breathing test group, volunteers were instructed to inhale through one nostril for 6 seconds, hold the breath for 6 seconds, and then exhale out the other nostril for 6 seconds. This practice was done twice a day (am and pm) for 30 minutes over the course of 3 months. The fast breathing test group was instructed to take deep and fast inspirations and expirations for one minute and then rest for 3 minutes and to repeat this exercise 8-10 times over a 30 minute period twice a day for 3 months. The results showed that the in the slow-breathing group, basal heart rate was significantly decreased, the heart rate response to standing was significantly altered, the difference between heart-rate during a deep inhale and a deep exhale significantly increased, and there was no difference in heart rate during a prolonged Valsalva maneuver. Interestingly, there were no significant changes in the fast breathing group. The study demonstrated that slow deep breathing lowered basal heart rate, which is a function of the parasympathetic nervous system. The study suggests that decreased heart rate and blood pressure is accomplished by improving the tone of the vagal nerve and decreasing sympathetic discharge (Pal et al. 2004).

In another study, Pramanik et al. (2009) investigated the effects of deep slow breathing with and without the administration of hyoscine-N-butylbromide, a parasympathetic blocker drug. Volunteers (n=39) breathed at a rate of 6 breaths/ minute for 5 minutes with a 4 second inhale and a 6 second exhale while sitting in a comfortable seated position. The blood pressure and heart rate of each volunteer were measured before and after the breathing exercise. Another group (n=10) took the parasympathetic blocker drug and performed the same breathing exercise with the same parameters measured before and after the exercise. In the group that did not take the drug, systolic and diastolic blood pressure decreased significantly and the heart rate fell slightly. In the group that was administered hyocine-N-butylbromide, no significant change in heart rate or blood pressure was measured. This study shows a clear connection between slow deep breathing and the parasympathetic nervous system. Benefits from deep, slow, purposeful breath are the result of activation of pulmonary stretch receptors leading to the activation of the parasympathetic system and the inhibition of sympathetic activities. Over time, the activation of the parasympathetic system leads to improved functioning of the autonomic nervous system (Pramanik et al. 2009).

Improved function of the autonomic nervous system and a shift towards parasympathetic control can account for many of the reported benefits of slow, deep breathing, including decreased oxygen consumption, decreased heart rate, decreased blood pressure, improved immune function, and reduced stress levels (Jerath et al. 2006). The increased ability to meditate and the turning inward of the mind may be explained by another result of the activation of pulmonary stretch receptors. Hyperpolarization of neural and non-neural tissue has been observed in response to the stimulation of pulmonary stretch receptor. Hyperpolarization of nueral and non-neural tissue means that a larger stimulus is necessary to trigger an action potential in the tissue. This may mean that small physical disturbances and distractions are less disruptive because they are unable to trigger action potentials (Jeranth et al. 2009).

There is quite a bit of ongoing discussion and research regarding the effects of slow, deep breathing and other pranayama practices. Much of the interest surrounds how reported benefits can be explained in terms of human physiology and the root cause of many benefits have not yet be illuminated. While many will be better understood in the future, it is possible that some reported experiences surrounding pranayama may be a result of the placebo effect. Regardless of the science behind the practice, pranayama has brought physical, emotional, and mental benefits to humans for thousands of years and is a practice worthy of the interest it attracts.

Works Cited

Carrere, Jaganath. “Inside the Yoga Sutras. ” Integral Yoga Publications, Buckingham, Virginia; 2006.
Dharmashakti Yogin “Intensive Study Program and Yoga Intensive & Teacher Certification Program Training Manual.” Nob Hill Yoga, Albuquerque, NM; 2012.

Jerath, Ravinder, Edry, John W., Barnes, Vernon A., Jerath, Vanda (2006) “Physiology of long pranayamic breathing: neural respiratory elements may provide a mechanism that explains how slow deep breathing shifts the sutonomic nervous system.” Medical Hypothesis.

Pal, G.K., Velkumary, S., Madanmohan (2004) “Effect of short-term practice of breathing exercises on autonomic functions in normal human volunteers.” Indian J Med Res. 120: 115-121.

Pramanik, T., Sharma, H.O., Mishra, S., Mishra, A., Prjapati, R., Singh, S. (2009) “Immediate effect of slow pace Bhatrika Pranayama on blood pressure and heart rate.” The Journal of Alternative and Complementary Medicine. 15(3): 293-295.

Pratap, V., Berrettini, W.H., Smith, C. (1978) “ Arterial Blood Gases in Prana Yama Practice” Perceptual and Motor Skills. 46: 171-174.

Websites Consulted


Saturday, June 8, 2013

Dinner at Home

The move into our new house can best be described as fractured. We closed on the house on the Thursday before memorial day weekend. The highlight of the day was the electrical utility worker backing into my parked car while he chatted on his mobile - the first time I ever parked in my new driveway. The final walk through (my first time in the house) was otherwise uneventful and we drove the hobbled Fit to the lawyers office. The signing of papers was long and boring, and the grumbling in my tummy did not help my patience. Dealing with insurance companies and making sure the Fit was safe to drive ate up our allotted time for lunch. There was some hold up in the communication between the loan office and the lawyers office, and we sat for an hour waiting for final clearance to be passed down to issue checks to the sellers and us. I was not pleased. Eventually we gave up, said we would come back later to pick up the checks, and we raced to find something to eat. Jamie and I killed some Moe's Burritos; I even ate all the complementary chips with my burrito and started in on Jamie's chips.

Officially homeowners, Jamie dropped me off at our friends' apartment so I could finish up the lesson plans I created for my summer trip. Jamie graciously brought the Fit to the autobody shop and procured a rental vehicle. After loading up the rental, we drove to our new house for a celebratory champagne toast with friends. Jamie and I fell asleep that night on an air mattress is an empty house, that we owned.

The next morning, Jamie whisked me to the Valdosta airport, which is even smaller than expected. I flew to Atlanta and then on to Raleigh for Broadreach summer staff training. After a week of learning about the other trip leaders, role playing possible trip scenarios, playing games, and finding out about my students and trip itinerary, I flew back to the tiny Valdosta airport. Jamie picked me up with an exuberant little Gnasher pup and we did some house shopping and went out to dinner. This night we fell asleep in a house full of unpacked boxes, but we slept on our own bed (my first time in a real bed in almost a month!)!

The following morning, Jamie's alarm starting complaining at 5:00am. I grudgingly climbed out of bed and drove Jamie to his squadron. He was on his way to N. Georgia for a week of SERE training. I spent the week unpacking boxes, teaching yoga classes, reading about Thailand, and resuming my "Clean" cleanse to get my digestive tract back on track after eating lots of unhealthy (SYSCO) food at Broadreach training. The "Clean" program requires smoothies to be consumed for breakfast and dinner; solid food is only prescribed for lunch, and I usually just have a salad and some almonds.

The point of all this, is that when Jamie got home last night we had technically owned our house for 2 weeks, but I had not cooked dinner in the house once yet and we had not eaten dinner together in our new dining room at all. So, it was a big event! Our very first dinner together in our new home needed to be healthy, filling, and delicious. I decided to try a recipe for veggie pasta that I had seen in "Natural Health" magazine that would allow me to stay pretty close to the regulations of the "Clean" program, which outlaws gluten, soy, corn, sugar, nightshades, dairy, and other things. There were some tomatoes in the recipe, but of the foods eliminated in the clean programs, tomatoes seem to be less toxic to my body than others (dairy is the worst). Now, when I say veggie pasta, that is a bit deceptive, the "pasta" is actually very thinly sliced zucchini and carrots. In the magazine picture, it really looked like multi-colored spaghetti. I think mine ended up looking like just a pile of cooked vegetables, but it did taste pretty good.

Olive Oil
Salt  & Pepper
Freshly Dried basil, thyme, oregano (from the neighbors garden)
Broccoli Florets
Jalapeno pepper (from neighbors garden)
2 yellow zucchini (neighbor!)
1 green zucchini (neighbor!)
2 Carrots
1 Red Pepper
Baby bella mushroom
1 can diced tomatoes

Wash all veggies. Cut the ends off of asparagus and cut into 1 inch pieces, before submerging in boiling water until just soft. Remove soft asparagus with a slotted spoon and drop into a bowl of ice water. Cook broccoli florets in an identical manner.

Slice carrots and zucchini into the thinnest strips your cutting ability allows. Mine ended up a bit thicker than they should of been, which diminished their "spaghettiness." Submerge in boiling water until limp when picked up by the middle and then plunge into a bowl of ice water.

Dice garlic and onion and saute with olive oil in a large pan over medium heat. Sprinkle in salt, pepper, and herbs. Clean and cut mushrooms into bite-sized pieces and add them to the pan. Cut the red pepper and jalapeno pepper and add to pan. Finally, add the can of tomatoes to the pan. Continue to cook over medium heat  until liquid from tomatoes comes to a boil, then lower heat and cover to keep warm.

In a separate pan, saute zucchini, carrots, asparagus, and broccoli with olive oil. Serve the zucchini, carrots, broccoli, and asparagus first and arrange on the plate as if pasta. I used tongs to grasp the veggies and arrange them on the plates. As you can see mine didn't really look like pasta, but it was close.

Use a ladle to heap the tomato and veggie mixture on top of the zucchini and carrot "pasta."  Here it ends up looking like a giant pile of veggies, but with a little more skill it could certainly look like a veggie pasta with multi-colored noodles. 

Since it was our first dinner at home together, I actually set the table. Our table looks rather small in our new, large dining area. We have so much more space in our new house - all of our things look a little dwarfed. 

This recipe was a great first dinner in our new home. It was relatively quick and simple, but most importantly it was made up of all healthy, whole ingredients, with several even being super local (next door). I did have fun preparing it, even if it did not look magazine perfect. I feel happy and contented to have set the tone for many wholesome meals to come! I am excited to start producing more and more food in my own yard and finding creative ways to prepare them. 

Coming up... many adventures in owning our own home (yard and home projects), but first a summer teaching in Thailand!