Swami Sivananda, in his book Swara Yoga, states that, Swara yoga is an ancient science that has analysed the working of the life-principle, prana, and the functioning of life within this body. It deals with the various channels along which the prana vibrates within the body animating it. It also prescribes means to regulate the flow of prana to ensure good health and longevity. This science, or yoga of swara, is more subtle than the science of pranayama (yogic breathing), which when compared to the former, is but a bare outline of swara yoga. This yoga of breath should be practised under the guidance of a fully-qualified yogi.
Swara means the air breathed through the nostrils. Swara also means breathing. The breath is not always equal in both nostrils. In fact, it is rarely equal. While it stops functioning in one of the nostrils, it rises in the other. This rising or falling of the breath in one or the other nostril, is called swardaya. The ancient rishis found certain things peculiar in the rise and fall of the breath in each of the two nostrils that affected and governed their various activities. The sustenance of life in this body, the functioning of the various internal organs, fullness of health or appearance of disease, equanimity or tossing of the mind, all depend on the flow of breath in either of the nostrils. They recorded their experiments of this analytical study of the functioning of the breath and termed it swardaya.
Success in life, accumulation of wealth and attainment of mental peace depend upon one’s health and activities. Through the practice of swara yoga, the individual seeks to control both of them. This ancient science cautions about diseases that may appear in the future and prescribes remedies for diseases that may be latent in an individual. It advises proper moments to undertake fresh activities, so as to attain maximum good.
– (Swara Yoga, p. 10–11)
If a person is in normal health, the breath will alternate in each nostril approximately every hour and fifty minutes. In most people, the change of breath from one nostril to the other varies a great deal owing to conditions such as unnatural living habits, wrong diet, disease and lack of proper exercise. All poor habits of living have some effect on the breath, diverting it from its normal flow.
Often one of the nostrils is blocked. The flow of air in and out of the lungs is thus limited to the other nostril. According to swara yoga, the breath in the right nostril is said to be hot, while the flow in the left is cool. Symbolically they named the subtle channel (nadi) which corresponds to right nostril breathing as Sun breath, or pingala. The nadi corresponding to left nostril breathing is referred to as Moon breath or ida. The energy that flows through pingala nadi or Sun breath produces heat in the body which is catabolic, efferent and acceleratory to the organs of the body; while the energy of the Moon breath in ida nadi is cooling, anabolic, afferent and inhibitory to the body organs.
When the breath continues to flow in one nostril for more than two hours, it is a symptom of derangement, caused by an excess of heat or cold. If pingala is more active, the heat of the body increases and there will be mental and nervous disturbances. When ida is more active, the metabolic activity of the body becomes low, producing cold and lethargy and suspended mental activity.
The main purpose of the alternate nostril breathing (anuloma viloma) exercise is to create and maintain an equilibrium in the catabolic and anabolic processes in the body and to purify the nadis.
In the recent past neuroscience and neuropsychology have developed around the discovery of the relationship of different parts of the brain with different mental and physical capacities. One major discovery by researchers is that the brain consists of two very different parts, each part responsible for very different ways of interacting with the world. Researchers found that the left side of the brain which controls the right side of the body, including the right nostril (interestingly, the ancient swara yoga texts assign the pingala, corresponding to the right nostril, to the left side of the spinal cord) works from an approach to life which is logical, sequential, analytical and outer-directed. Activities that are aggressive, physical and mathematical are said to be left-brained.
The right side of the brain, which controls the left side of the body, is working from an approach to life which is intuitive, simultaneous, holistic and inner-directed. Research reported on the rhythmic play between the two hemispheres of the brain measuring brain waves simultaneously on both sides of the brain. When the brain waves were carefully compared it was shown that one hemisphere dominated, giving way to the other, with each dominating for periods ranging anywhere from 25 minutes to 200 minutes with an average of two hours. The nasal cycle—the airflow in the right and left nostrils—was also measured, and it was found that the rhythms of the nasal cycle and the hemispheric cycles were tightly coupled. When the airflow was predominately through the right nostril, greater relative amplitudes of EEG activity were found in the left hemisphere, and vice versa. Shifts in mood can be correlated to shifts of hemispheric dominance. Mental disorders such as manic depression and schizophrenia can be related to the situation where either one or both of the hemispheres are over- or under-activated or somehow dysfunctional.
From a knowledge of the relationship between the flow of the breath through the right or left nostril and corresponding mental states, yogis have made two important applications. The first, as we have seen above, is to balance the mind through equalising the flow of breath. The second is to adapt either the specific activity or the flow of the breath, at any given moment, to be complementary to each other. The rule of thumb according to Swami Sivananda: Do calm acts during the flow of the Moon (ida, left nostril). Do more active work during the flow of the Sun (pingala, right nostril). Do acts resulting in the attainment of psychic powers, yoga and liberation during the flow of sushumna (both nostrils equally, awakened only through intense purification and spiritual practices).
It takes little speculation to realise, even with the predominately left-brain, pingala-dominated Western mind, that the more both sides function in conjunction with their complementary functions, the more creativity, intelligence and balance there is.
Without going too deeply into the practice of swara yoga, which in any case should be done only under the guidance of a qualified teacher, there are some practical applications that can help anyone who makes the effort to regulate the breath.
Eating and sleeping should be done with the pingala or right nostril flowing. Digestive fluids and heat are stronger during pingala. Sleep at this time is deeper. You will thus find that your sleep is more profound if you sleep on your left side, which forces the breath into the right nostril.
In all external activities which are calculated to do good—individual and universal—see that they are started with the ida or left nostril functioning. The following are some of the good acts that can be begun during the flow in ida: entering a new mode of life, starting studies, travelling, meeting friends, erecting buildings, cultivation, taking new appointments, marriage, wearing new clothes, preparing nourishing medicines. Sushumna (breath in both nostrils) should always be reserved for spiritual good, for concentration and meditation, and for kumbhaka (retention of breath).
The evidence brought forth by these studies is encouraging to all of us who have made regular practice of pranayama breathing techniques and who attempt to put into practice the subtle inner science of swara yoga, or mind control through breath control. We await modern neuroscience making the multi-dimensional breakthrough when they ‘discover’ that all bodily functions, including those of the brain, are fueled on a psychic or mental level by prana, and that the mind (intellect, emotions, subconscious and ego) is located in the astral body which is distinct from the physical brain.