This is an excellent exercise for balancing the nervous system. Practicing it can calm you down when you feel hyperactive, stimulate you when you feel lethargic, and center you when you feel distracted. The prolonged exhalations release tension, the deep inhalations draw prana into the solar plexus, and, when you retain the breath, prana is directed to the area of the third eye, bringing about mental poise.
Pranayama should feel pleasant and never stressful. Beginners will find the ratio of inhalation to retention and exhalation in the complete technique too challenging, so start with Single Nostril Breathing before progressing through the levels. You will feel the benefits, no matter which level you practice.
Place your right hand in front of your face in Vishnu Mudra. Close your right nostril with your thumb. Inhale for three seconds and exhale for six seconds through your left nostril. This is one round. Practise up to 10 rounds. Repeat on the other nostril: close your left nostril with your ring finger and inhale and exhale through your right nostril. Practise 10 rounds on each side regularly over a few weeks. Gradually increase the ratio of the exhalation to the inhalation—first inhale for four seconds and exhale for eight, then lengthen the ratio to 5:10, and finally to 6:12.
After mastering the 6:12 ratio of Single Nostril Breathing, move on to Simple Alternate Nostril Breathing. Closing your right nostril with your thumb, inhale through your left nostril for four seconds, close your left nostril with your ring finger, open your right nostril and exhale through it for eight seconds. Inhale through your right nostril for four seconds, then exhale through your left nostril for eight seconds. Practise up to 10 rounds. Gradually increase the inhalation:exhalation ratio to 5:10, then to 6:12, and finally to 7:14.
Once you have mastered the 7:14 ratio of the simple Alternate Nostril Breathing, move on to Alternate Nostril Breathing with Breath Retention. Inhale through your left nostril for four seconds, close the nostril, hold your breath for eight seconds, then exhale through your right nostril for eight seconds. Then inhale through your right nostril for four seconds, hold your breath for eight seconds and exhale through your left nostril for eight seconds. Practice up to 10 rounds. Increase the inhalation:retention:exhalation ratio to 5:10:10, then to 6:12:12, and finally to 7:14:14.
Using a mudra, or energetic seal, like Vishnu Mudra helps to contain prana within the body, but is useful on a purely physical level, too, providing a tangible aid to concentration.
As you improve, try a longer breath retention—complete Alternate Nostril Breathing. Inhale through your left nostril for four seconds, hold the breath for 16 seconds, and exhale through the right nostril for eight seconds. Then inhale through the right nostril for four seconds, hold the breath for 16 seconds, and exhale through the left nostril for eight seconds. Practice up to 10 rounds. Increase the inhalation:retention:exhalation ratio to 5:20:10, then to 6:24:12, and finally to 7:28:14.