Breath and life span
Ancient seers measured life by the number the breaths (inhale plus exhale) we take. On an average a normal human being breathes at a rate of 15 breaths per minute or 21,600 breaths per day. Now, the maximum life span allocated to an individual is:
15 breaths/min x 60 mins x 24 hours x 365 days x 120 years = 9,46,080,000 breaths.
The total number of breaths allocated to each individual is fixed, however, the rate at which these breaths are consumed varies dramatically from individual to individual. Because of the stress associated with unfulfilled desires of the modern materialistic world, humans always breathe at a much higher rate. As the mind is more subtler, stress immediately affects the breathing rate. This causes breathing to be shallow and the number of breaths allocated are consumed at a much faster rate. When a human being is under stress, along with the reduced time of each breathing cycle, the space up to where the breath is projected from the nostril increases e.g. fear causes quick shallow breathing and one can feel the breath reach up to the navel. This dramatically reduces the lifespan of humans in the modern age. So, the first way to increase life is to spend time alone with the senses internalized , and take deep long rhythmic breaths to relax the mind.
You need not learn any advanced technique just yet. Just sit or lie on the ground with the spine straight and take deep long breaths without using force, but with full awareness of every breath. The best time for this is before sunrise, at the junction of day and night,called the Sandhi Kala. As you proceed with this breathing, the time span of each breath continuously increases and after a some time you will achieve a rate of 5-6 breaths per minute or even lesser. Now, you will feel completely relaxed and closer to the center.
It is very difficult to remain aware of the breath while doing work, as the mind along with the senses, being externalized, continuously distracts the individual. This method of breath awareness is the first dharana or method mentioned in the Vijnana Bhairava Tantra and was also used by the Buddha in the form of Anapanasati yoga.
As the Manomaya Kosha or the mental body is more subtle than the breath or the Pranamaya Kosha , breathing alone is not sufficient. This breathing must be accompanied with mind awareness for faster results. It seems too simple a method to be just aware of every inhale and exhale. Try it for thirty minutes and see the results. Very few people are relaxed and aware enough to focus on each breath for more than 3-4 minutes. So, the secret to a long life is deep,long rhythmic breathing and with awareness, liberation.
Now more on breath. Even though we feel only the air we breathe, this is at a gross level. Air is just the medium through which Maha-prana or cosmic consciousness enters the human being. The Prana Shakti or life force, at the individual level assumes the five sheaths from the physical sheath to the bliss sheath , which is closest to the spirit or the supreme self. Now, the Pranamaya Kosha or the vital energy sheath divides into sub-pranas:
Prana , functions in the thoracic region
Apana , functions below the navel
Samana , located between the heart and navel
Udana , functions in the throat and face region
Vyana , pervades the whole body
One of the keys is to retain this middle breath between inhale and exhale and lengthen the retention time though various techniques.
The universal prana which is now individualized is spread through the entire body by 72,000 subtle channels called nadis. Out these 72,000 nadis, 10 are important. They are:
Ida ,Pingala, Sushumna, Gandhari ,Hastijihva ,Poosha ,Yashaswini, Alambusha ,Kuhu and Shankhini. Now Ida ,Pingala, Sushumna the negative, positive and neutral channels,are the most significant. Ida is the negative or female channel responsible for cooling and relaxation. Pingala is the positive or male channel which energizes the body. Ida is related to the conscious mind, Pingala to the sub-conscious and Sushumna to the un-conscious mind.
Ida runs on the left side of the spine, Pingala on the right and Sushumna in the center. All these three nadis join together at the level of the third eye and then proceed together as one.