The Importance of Pranayama:
Pranayama, refers to the practice of mastering Prana, the life element in the body. Pranayama holds the key to tapping this Bio-energy to attain improved physiology and spiritual elevation.

As a result of the everyday stresses of modern, urban life, the increased air pollution, the increased levels of radioactivity in the atmosphere, and the depletion of the ozone layer, breathing has, in response, become much more shallow and rapid. This in itself, is a precursor to many chronic respiratory ailments.

Slow, relaxed, and deep breathing is a prelude to learning Pranayama. Although the total length of time required for a single cycle of breathing will vary with different persons, certain ratios of the periods needed for inhaling, pausing and exhaling are recommended. The period occupied by exhaling should be about twice as long as that occupied by inhaling. Practice inhaling and exhaling without a full pause. Then, when you feel ready, hold your breathing for a pause which is comfortable. With continued practice, this pause can be extended to a duration which is double that of the inhalation or equal to that of the exhalation. Advanced practitioners of yoga hold their pauses to four times the duration of inhalation and double the duration of exhalation. This helps to alleviate some of those ailments, improves the body's respiration and increases oxygen to aid cellular respiration. The process requires that you inhale, hold and exhale to allow freshly oxygenated blood to reach your neck muscles, tongue, throat, nose, ears, eyes and brain, and the entire sensitive area of your skull. This is especially helpful if you have a mild headache, or are overworked, tired, tense or experience sleeplessness five minutes of this relaxed breathing even has an impact.
Scientific proof of this cause-effect relationship has yet to be established within Allopathic medicine. However, there are several observational cases of chronic ailments where Pranayama has brought about considerable relief.

Guidelines for Breathing Exercises:
To understand the logic behind these breathing exercises, it is best to understand the state of breathing when you are asleep. The frequency of breathing decreases significantly when you are asleep. Almost every hour, the right or the left nostril alternately becomes more active and permits the other nostril to rest and let the mucus secretions clean up allergy causing particles trapped in the membrane. In Yoga speak, the right nostril represents the 'Sun Channel'. This is the side for activity and sports. The left nostril indicates the moon and is good for mental activity and creative work.
The breathing process can be divided into inhaling (Puraka), exhaling (Rechaka), holding air in the lungs, and maintaining a gap between exhaling and inhaling for another breath (Bahya -Kumbhaka).
The objective of breathing exercises which should only be practiced under the guidance of a qualified, experienced yoga instructor, reduce the rate of respiration from 16 cycles per minute to just 4 per minute. An average adult breathes 16 to 18 times per minute, varying according to age, state of health, physical activity, body weight, etc. In order to do reduce the rate, the breathing cycle has to be prolonged from 4 seconds to 15 seconds. This should be done without any strain on the lungs, the diaphragm or the chest muscles.

An ideal place to begin breathing exercises is a clean quiet room facing East or North. The best time to practice Pranayama is early in the morning or at sunset. The room should have adequate ventilation of fresh air, yet it should be draught-free. Avoid open places with lots of dust or a strong breeze. Make sure that you are not constipated or under any severe physical or mental strain when practicing these exercises.

Beginners are advised to avoid seasons that are too cold or too hot and the rainy season with its high relative humidity.

A person who is more advanced would typically follow an intensive routine of 4 sessions a day - morning, noon, evening and midnight. For a comfortable experience, one can use a folded woolen mat or a floor exercise mat - the sort a local gym or aerobics class might have.

Pranayam Kapalbhati :
Kapalabhati is a breathing technique used specifically for cleansing. It removes mucus from the air passages, relieves tension and clears blockages in the chest. This is achieved via deliberately breathing faster, and at the same time using only abdominal breathing, not chest breathing. The breath is short, rapid, and strong using the lungs as a pump, and creating so much pressure to clear air passages, from the lungs up through the nostrils. Kapala means "skull," and bhati means "that which brings lightness." Kapalabhati is a good thing to do when feeling heavy or dizzy in the head. For problems with the sinuses or numb feeling around the eyes, kapalabhati can also be helpful.

The kapalabhati and bhastrika breathing techniques share the same general principle, namely that we clear the nasal passages with the force of the breath. As mentioned under bhastrika, we must be very careful with these techniques because there is a danger of creating tension in the breath. We may also become dizzy when we breathe rapidly; for this reason we always conclude the practice of kapalabhati with some slow breaths. It is important not to breathe rapidly too many times, but after a few rapid breaths take several slow ones in which we emphasize the long exhalation.