To Breathe is to live
It is possible to live without food for many days, without water for several days but without air, normally, not more than a few minutes. Thus breathing is the great vital source of energy. It is life. Each and every activity of life is intimately connected with the process of breathing.
'Breathe is life'. This aphorism states that our life is controlled by breath. In the Preksha system of Meditation it has been taken as a basic principle. We inhale oxygen and convert it into vital energy, by the process of internal respiration. Proper breathing, therefore, can become an important tool for physical as well as mental health and happiness.

Supreme importance of proper breathing cannot be over-stressed. Many of the symptoms of poor health are caused by insufficient oxygenation of blood, and slow circulation. Not only are the nerves, glands and vital organs inadequately nourished, but the excretory systems cannot function properly and the bodily waste- products are not removed efficiently. Not only do we breathe badly, but often the purity of the air leaves much to be desired. Consequently, our nervousness and irritability increases and even the slightest physical effort may leave us exhausted. Worst of all, our resistance to diseases is reduced drastically and we develop greater susceptibility to germs and infections. Correct breathing, by ensuring complete ventilation of the lungs, immunizes us against diseases like Tuberculosis.

In a single day we breathe about 23000 times. Depending upon one's posture as well as physical and emotional state, the average volume of air taken in a single breath is 1/2 to 1 litre. With proper attention, this volume may be increased upto 4 to 5 litres. In other words, careful reorientation of our breathing system can increase at least five-fold our ability to use oxygen and eliminate carbon dioxide. However, we can train ourselves to breathe more slowly and more deeply. The rate can be easily reduced by 4 to 5 breaths a minute. Slower rate results in reduction of wear and tear in the entire body, less work for the heart, lower blood-pressure and quieter nerves.

Exhalation
Scientific breathing begins with a slow, calm and complete exhalatioa Contraction of the abdominal muscles helps to reduce evacuate the lungs by raising the diaphragm. More complete the evacuation, greater the volume of fresh air to enter the lungs and purer the air in contact with alveolar surfaces. Unless we first breathe out fully, it is impossible to breathe in correctly.

Inhalation
Having emptied the lungs, the next step is to fill them upto the maximum extent The total volume of air which the lungs are able to contain is known as the vital capacity, which is about 6 litres. Before one can contemplate to increase this capacity, full use must be made of what is already available. Scientific breathing enables the practitioner to do this.
Adequate supply of oxygen is essential for the proper functioning and vitality of the cells, it is therefore vitally important to breathe correctly so that every cell can receive oxygen. The optimum interchange of gases in the lungs occurs when the breathing is deep, complete and slow.

"To breathe is to live" undoubtedly a good adage but to breathe correctly that is slowly, silently and deeply is to live long and keep healthy. Once the technique of complete breathing is learnt, it can be practiced anywhere and at any time. In fact, it could and should become the habit rather than an exercise. Way of complete breathing should become the normal way.

In the following chapters, the reader will find the way of practicing complete breathing. Having regulated one's breathing, the practitioner will increase one's operational efficiency by practicing perception of breathing because this exercise trains the mind to concentrate and mental concentration is the key to efficiency.