Respiratory Efficiency

By Casey Adams, Ph.D.

Respiration is not just something the lungs do as oxygen crosses through the alveoli into the bloodstream. Respiration is also what our cells do to produce energy. The most efficient form of cellular respiration utilizes oxygen and glucose to cycle phosphate atoms between ADP and ATP to produce energy. This is called oxidative phosphorylation—also referred to as aerobic respiration. The cells can also produce energy without oxygen (anaerobically), but this gives only about 5% of the energy efficiency of aerobic respiration.

Anaerobic respiration also yields greater levels of acidic (H+ rich) chemistry in the bloodstream, creating a condition called acidosis. While many trainers assume lactic acid causes muscle fatigue, confirmed research indicates that blood acidosis is the more likely culprit in fatigue, while lactic acid is actually re-utilized by mitochondria in energy production.

Oxygen is the greatest nutrient of the body—vital to the operation of every organ and tissue system. Oxygen also provides an environment less hospitable to bacterial or viral invasion. Poorly oxygenated and highly acidic carbon dioxide-blood opens the door to a host of disorders. In other words, our body’s health and performance relates directly to oxygen supply. This is where the lungs come in.

Increasing Lung Capacity

The average lung capacity of an adult is about 6000 cubic centimeters (about a gallon and a half), with variances for age, height and sex. Both capacity and efficiency can be increased with cardiovascular exercise. Most of us breathe only 500 to 700 cc in and out. This means we are utilizing little of our true lung capacity.

One of the best ways to increase lung capacity is through bursting. Bursting is cardiovascular exercise with periodic bursts of speed or intensity. Workouts including running, swimming, climbing, surfing, basketball and biking provide a good platform for bursting. The burst should be sustained until oxygen debt is achieved and heavy breathing is noticeable. This is immediately followed by a return to a sustainable pace. An excellent way to achieve this is running or biking on hilly terrain.

Lung capacity can also be increased through deep breathing exercises as described below, and by short-period breath holding. This means holding the breath for a few extra seconds before breathing out. (Holding the breath as long as possible is dangerous and not advised.) Research has shown that lung capacity and respiration efficiency can also be increased through high-altitude training.

Clearing the Lungs

Efficient oxygen delivery requires our lungs to be clean and clear of obstruction or inflammation. As air moves through the nostrils to the pharynx, larynx and trachea, it passes over mucous membrane cells lined with fluid and tiny hairs called cilia. Cilia capture foreign particles with a web of sticky mucous before they can enter the lungs. Meanwhile bacteria and viruses are caught and attacked by the macrophages that line mucous membranes, and the air is warmed or cooled closer to the body’s core temperature.

Once through this maze of filtering and conditioning, incoming air reaches the two bronchi on its passage to the lobes of the lungs. Because the bronchi fan out through into some eight million tiny branches called bronchioles, this system is called the bronchial tree. Eventually the airflow terminates at tiny air sacs at the end of the bronchioles called alveoli. These little round sacs interface with the bloodstream. They are lined with a thin membrane of water and surfactant. The surfactant prevents the surface tension of the water from collapsing the alveoli during the exchange of oxygen and carbon dioxide.

The delicate chemical balance of both the alveoli surfactant and the mucous lining in the breathing passages can be altered by smoking, air pollution, chemicals and fragrances. Should our filtration systems be unable to remove pollutants before they enter the bronchial passages, our bronchi mucosal membranes will launch an immune response to rid them and repair the damage. This immune response accompanies inflammation. The inflammatory response enlarges the mucous membranes, tightening the air passages. This naturally reduces our lung capacity and oxygen consumption.

Furthermore, most of us leave 1200 to 1500 cc of air standing in the lungs as we breathe. Most adults have the capacity to move 4800 to 5200 cc out with one deep exhalation. This means we can easily clear out most of that stale air, at least periodically, replacing it with fresh, oxygenated air. We refer to this as flooring. Flooring can also be used to cleanse the lungs of any uncaptured pollutants.

Air Quality

Many think air quality has little to do with athletic performance. Yet inflammation caused by air pollution inhibits lung capacity and oxygenation, reducing cellular respiration efficiency.

Our indoor air is often the primary cause of lung inflammation. We should avoid or repair ‘sick’ buildings where old and moldy ventilation systems, carpets and basements circulate fungi-laden air or soot from nearby pollution sources. Meanwhile, furniture built with formaldehydes can outgas into our indoor environment in warm temperatures, and household chemicals can leach volatile organic compounds into our indoor air.

Neither ozone nor ion generator systems have proved to effectively remove chemicals, dust, dander or allergens (other than bacteria in the case of ozone) from indoor air. HEPA (high-efficiency particular air) filters provide a better strategy to help remove these pollutants. HEPA filters are designed to pick up 99.9% of particulates .3 micron or larger. Putting HEPA filters on air duct systems can seriously help remove pollutants that irritate the lungs.

Placing between two and five houseplants per hundred square foot of space can significantly remove carbon and raise indoor oxygen levels. Research from the Mississippi Stennis Space Center concluded that indoor plants also absorbed and broke down formaldehydes, tricholoethylenes, benzenes and zylenes. Better performing plants include lady palms, rubber plants, English ivy, and areca palms. Removal rates can range from 1000 to 1800 micrograms per hour. One study done in Norway found 23% less complaints of fatigue and sinus congestion among workers surrounded by plants.

Breathing in through the nose and out the mouth is also a good strategy to properly utilize sinus and pharynx filtering mechanisms. This also helps acclimate breathing air to the body’s temperature before irritating the lungs. Nose-mouth breathing becomes critical when exercising in polluted areas and in cold or hot temperatures.

There are several natural strategies should our lungs become inflamed or congested. A humidifier can be used to moisten the mucous membranes, assisting in the lung’s detoxification systems. We can also add eucalyptus, camphor and/or methol oils to the humidifier vent. These help expand the bronchi and stimulate the immune system to clear toxins. Herbal teas with eucalyptus, mullein, licorice, marshmallow and flax seeds have been used in traditional medicine to help clear lung congestion.

Deep Breathing Exercises

It is not difficult to utilize the lungs better than most of us do now. With a little practice, we can not only increase lung capacity, but we can increase replacement of carbon dioxide-rich acidic blood with alkalizing oxygenated hemoglobin to improve moods, vitality and immunity.

There are two basic methods of deep breathing: core breathing and diaphramic breathing. Core breathing begins from the lower abdomen. Start by slowly pushing out the abdomen around the belly button, followed by a pushing out the upper abdomen in a slow, two-step fashion. This contracts the diaphragm to expand the intercostals and enlarge the lungs. As the lungs fill with air through the nose, push out the abdomen with a final gentle push and hold to expand the lungs to capacity. After holding for 2-3 seconds while relaxing, slowly push air out the mouth by contracting the upper abdominal muscles. This relaxes and pushes the diaphragm up, changing the lung pressure to empty the lungs. Complete the exhalation with flooring: contract the lower abdominal muscles to empty the bottom of the lungs, and hold for 2-3 seconds before starting the cycle again.

Core breathing is deeply relaxing and often used for meditation. Many of us unconsciously breathe like this when we are sleeping. Core breathing is mostly impractical unless we are lying or sitting still and able to focus and relax. It can also make us sleepy: It isn’t suggested while driving or listening to a lecture.

The more practical method of active deep breathing, one that can be done most anytime, is diaphragmic breathing. Here we focus upon the upper abdominal region. To start, slowly push out at the top of the abdomen, enlarging the diaphragm. After the lungs fill through the nose to balance the pressure differential, hold the pushed out upper abdomen for a second or two. Now begin tightening the upper abdominals, pursing the breath out through the mouth until the lungs are emptied completely.

Diaphragmic breathing can be done throughout the day. It is generally vitalizing, giving us increased energy and clearer thinking. The more we practice diaphragmic breathing the more we will automatically breathe deeper. This will bathe our blood and cells with sufficient oxygen to improve our vitality, increase our athletic performance, and improve our brain health for years to come.