The majority of people take breathing for granted without realising that it is the most significant and systematic of biological functions. If these people were to read the swara shastras they would be amazed to learn that the breath flows mainly through one nostril at a time. In these texts it explains how each nostril stays open for a period of one ghatika, or 60 minutes, although other sources give the duration to be 90 minutes. The breath flowing in the right nostril is known as the right swara and the flow in the left nostril is called the left swara. The cycles alternate rhythmically throughout the day and night, representing the domination of ida/pingala nadis or the negative/positive influxes of energy and attitude. At the end of each cycle, the breath flows evenly for 1-3 minutes. This signals the period when the energy is neither negative nor positive but neutral, and sushumna nadi is flowing.
These ancient teachings correspond remarkably well with the findings of modern neurophysiologists and neuroanatomists. Investigations into the structure of the brain have revealed that it does not function as a single unit, but as a combination of two bilateral hemispheres. The hemispheres are linked by a thin membrane called the corpus callosum, which conducts energy between them.
The right hemisphere has been found to govern the functioning of the left side of the body, and operates in conjunction with ida nadi. Conversely, the left hemisphere connects to the right side of the body and relates to pingala nadi. Researchers postulate that breathing through the right nostril directly stimulates the left hemisphere and breathing through the left nostril activates the right hemisphere.
Neurophysiologists have found that the brain hemispheres actually do alternate in activity every 60-90 minutes just as stated in the shastras. Also, after each cycle is completed, nerve impulses are discharged in the corpus callosum for approximately 4 minutes. This corresponds to the period when the swara flows evenly through sushumna. Furthermore, the active hemisphere stimulates the corresponding nostril into operation. Therefore, one nostril remains open while the other is slightly blocked, and this is known in physiology as 'alternate rhinitis'. Thus, through the study of the brain hemispheres, scientists have confirmed the descriptions of the alternating positive/negative cycles given in the swara shastras.
These investigations have also shown that during the first half of the cycle, the energy gradually builds up to a peak during which the body and mind become acutely alert and sensitive. After this stage the energy declines for the remaining 30-45 minutes. People who suffer from chronic illnesses may find that they undergo attacks of pain or disturbance during this energy peak. For example, epileptics have been observed to convulse mainly at this particular time.
Discovery of this important link between the brain mechanisms and the breath leads us to wonder whether man is actually responsible for any of his actions, or is just reacting to pre-programmed computer circuits installed in the brain. The answer to this question is given in the Yoga Chudamani Upanishad, which describes how the individual consciousness (jiva) is pulled by the action of the breath. It is also explained in the Hatha Yoga Pradipika (4:21) that: "He who has controlled his breath has also controlled the activities of the mind and controlling the mental activities controls the breath."
Modern researchers have investigated the science of the breath and its influence on the mind, but they have not yet recognised that the nadis and the breath are linked to the movements of the sun and moon, which was well known to the ancient seers. It has been recorded in the Pawana Vijaya Swarodaya that during the dark fortnight of the lunar cycle, when the moon is waning, surya nadi (pingala) becomes active at sunrise on days 1-3, 7-9 and 13-15. The nadis function alternately in 60-90 minute intervals throughout the day and at sunset chandra nadi (ida) begins to function. Then, on days 4-6 and 10-12 chandra nadi flows at sunrise, and surya nadi at sunset. During the bright fortnight, when the moon is waxing, the reverse process takes effect; at sunrise on the first 3 days, chandra nadi opens, and so on. The breath should be checked at these times to make sure that the appropriate nadi is functioning.
If the right or left swara happens to function out of rhythm with the solar/lunar cycles, then any one of the following methods can be used to synchronise the breath:
The state of our body and mind is reflected in the alternation of the breath cycles. If either nadi predominates for too long, this is a sign that one of the branches of the autonomic nervous system is being over stressed, and only one of the brain hemispheres is being fully utilised. The physical and mental energies are unbalanced, the personality is only half developed, and sickness of some type is inevitable. In order to avoid this situation, there must be regular alternation of nasal activities.
The type of sickness which occurs indicates which nadi and energy has been flowing excessively. Many problems resulting from poor digestion, such as flatulence, indigestion, diarrhoea, dysentery, cholera and dyspepsia, as well as respiratory disorders and male impotence, are associated with excessive flow of ida.
On the other hand, such stress related problems as hypertension, acidity and ulcers arise from the over-activation of pingala.
The Shiva Swarodaya states that for good health and long life the sadhaka or yoga aspirant should maximise the flow of ida during the day and the flow of pingala at night. This counterbalances the natural tendency of the body to become overheated during the day, and overly cool at night, and can easily be accomplished at night by sleeping on the left side. Now, research into this subject has revealed that incorrect sleeping position is an important factor contributing to many physical disturbances.
An investigation carried out in India by doctors showed that out of 48 dyspeptic patients, 2/3 slept on their right side as opposed to their left. The control group consisted of 7 healthy people who normally slept on the left side. When they were made to sleep on the right side, after one week they began to show signs of sluggish digestion. When they were allowed to resume their left sided sleeping position, their stomach disorders were rectified. Another survey of asthmatic patients showed that 7 out of 10 slept on their backs. Even if we do not suffer from any chronic physical ailments, we can benefit most by sleeping on the left side.
Once any disorder has set in, a change in the flow of the breath can bring some relief. If there is too much heat in the body, lying on the right side can help cool it and conversely, when the body is cold, lying on the left side can help warm it. During a fever, the active nostril can be blocked to balance the temperature.
Before the onset of any disease, the flow of the swara becomes disturbed, and if this is noted beforehand, the imbalance can be rectified and the sickness averted. Asthmatics feeling an attack coming on, can block the active nostril to help prevent or lessen the severity of the attack. Those who suffer from headaches should check their digestion, make sure they sleep on the left side, and when the headache occurs, block the active nostril.
Yoga talks about merging and harmonising, because that is the very meaning of the word. Swara yoga, therefore, brings about a state of total harmony through mediating the flow of the breath. How exactly is this to be accomplished?
The Hatha Yoga Pradipika (2:10) suggests a particular method of breathing so that all aspects of the body become balanced: "If the air is inhaled through the left nostril, it should be retained and then expelled through the right, and again inhaled through the right nostril, retained and exhaled through the left. Breathing through alternate nostrils rids the whole nadi system of impurities" and directly stimulates the brain hemispheres. This practice is called nadi shodhana pranayama. Thus, swara yoga also involves the practice of pranayama.
Swara is the breath, and prana is an essential factor of swara; therefore, the swara yogi will need to utilise the practices of pranayama. But pranayama should not be confused with swara yoga. Pranayama is primarily concerned with increasing prana through breath retention, whereas swara yoga is concerned with the nature of inhalation and exhalation. The practice of pranayama enables the swara yogi to directly influence and attune his awareness to the nature of his swara.