Breathing exercises, such as Pranayam, keep you healthy by various means. In normal course we do what may be called shallow breathing. The lungs are neither fully expanded nor contracted. Therefore the air flow in the lungs is restricted. Breathing exercises generally increase the volume of air flow providing more oxygen and removing carbon dioxide more efficiently.

In many breathing exercises you are told to hold your breath for some time. Depending upon the exercise you may be required to hold your breath either after inhaling, or after exhaling.

How does holding the breath help?

It is not possible to empty the lungs entirely; some amount of air will be there even after exhaling fully. Normally there are some small pockets inside the lungs in which air tends to remain stagnant. Air inside those pockets does not join the main flow of air. It gets depleted in oxygen and fresh supply does not reach there. Blood coming in contact with air in those pockets does not get fresh oxygen and carbon dioxide is not removed from that part of blood.

When you inhale air and hold your breath in that position, the air drawn inside the lungs gets more chance of mixing with stale air in those pockets. As more time is made available for air mixing, stagnant stale air is removed and supply of fresh air goes inside those pockets. Similar action takes place when you exhale air out and hold your breath. There is reduced pressure inside the lungs which draws out the stale air. The overall effect of these actions is that entire surface of alveoli, or air sacs inside the lungs gets larger amount of fresh air.

In Pranayam as you continue regular practice you are expected to increase the duration of holding the breath as well as number of times you do the exercise. You should increase both, not one at the cost of the other.

Holding the breath also helps you to concentrate better. In many breathing exercises, I will again take example of Pranayam, you are required to concentrate on breathing and visualize the flow of air. For example as you inhale, you may be asked to visualize that you are drawing in life-force or Prana along with fresh oxygen. While holding the breath you may be directed to visualize that Prana is getting absorbed in greater quantity. When you exhale you throw out toxins as well as bad thoughts and at the same time Prana gets distributed in the body. Visualization has remarkable influence on the effectiveness of breathing exercises.

When you are holding your breath it is difficult to think of anything except your breathing. To that extent it helps you in directing your concentration towards yourself.

The diaphragm, like any other body muscle also needs exercise. Breathing deeply and holding your breath provide exercise for the diaphragm.

I would strongly recommend that any breathing exercise, particularly Pranayam, should be done under the guidance of trained persons only.

Any exercise will work better for you when you know how the exercise is helping you. Next time when you do breathing or any exercise, just be conscious of what is happening in your body and you will get better results for the same effort.