WHAT IS PRANA?
Prana is the life energy that sustains us every moment of our life. Understand, it is not the same as the air you breathe in and out. Prana is the life energy that is carried by the air. For example, if you have to carry a truck of mud from one place to another, the truck is just the carrier. The mud is the real content you are interested in. Similarly, air is the carrier which carries the real content, prana. We don't need air to survive; prana is what is needed.
Prana is associated with five different types of movements or circulation in the body. They are: prana – inhaling of prana, vyana – prana staying inside the body, udana – prana spreading all over the body to every nook and corner, samana – prana leaving the body*, and apaana* – cleaning of the system.
Please understand that when your desires change, your prana flow or your air flow will change.
For example, if you are caught in lust or any intense desire, your inhaling and exhaling will become intense. The prana going in and coming out will increase.