Nasal Breathing

Sigmund Freud found that menstrual cramps were often related to an inflammation and discoloration of specific areas in the lining of the nose. When these are anesthetized, the menstrual pains disappeared until the effects of anesthesia wore off.
Modern research is also finding that emotional states are related to an over dominance of either right or left nostril activity. For example preliminary research indicates that some forms of depression are related to over-activity in the left nostril, while excessive airflow in the right nostril has been found to be associated with hyperactivity. This does not necessarily mean that a constantly overactive left nostril causes depression, or that an overactive right nostril leads to hyperactivity. What it does show is the connection between the way we breathe, certain neural conditions, and physical and emotional states.
Yoga science states that when you are doing active work, the right nostril should be open and dominant. Consciously working with your breath in this way gradually allows you to establish control over your breathing with your mind. The goal is to be able to establish sushumna, the ability to willfully direct both nostrils to be open equally at the same time.
The purpose of sushumna is to allow the mind to be deeply concentrated without effort.

THE COMPLETE BREATH

In this exercise all three mechanisms for breathing – diaphragm, chest, and collarbones – are brought into use. When you first practice this exercise, place your right hand on your upper stomach area and your left hand on your upper chest. When you breathe with the diaphragm, the right hand will rise on the inhalation and fall on the exhalation. The left hand will rise when you inhale with the chest mechanism. Once you are sure of the proper movement of the diaphragm, chest and clavicles, you can do the breathing without using your hands.
Inhale first, using the diaphragm and expanding the belly; then continue the inhalation by expanding the chest; then let the inhalation continue to the very top of the lungs. At which point a slight upward movement of the clavicles may be experienced. The exhalation is done in reverse motion, letting the clavicles drop slightly then letting the chest wall collapse slightly, then letting the belly collapse as the diaphragm moves upward, pushing the air out of the lungs. The breath should be slow and smooth, without any pauses or jerks.

BENEFITS:

The complete breath is a very useful technique to use when you are sitting at your desk and feel a lot of tension in your shoulders.
A few minutes of practice will be very helpful in reducing not only muscle tension but also mental fatigue.
The complete breath is an energizer and can be used any time you feel mentally dull, or need to be more alert. For instance, when you have been driving for some time and are beginning to feel a little tired, you can energize yourself by taking six or seven complete breaths.