Life is possible only because of prana. Prana is the universal energy of existence. The word literally means “breathing forth.” It is usually synonymous with the breath or with air (vayu). In the Rig Veda, the oldest Hindu text, prana is claimed to be the breath of the cosmic purusha.  But prana itself is an overarching term with many subcategories. Learning how prana works and how to free this energy is part of the psycho-spiritual practice known as pranayama.
Vayu, meaning air, is another synonym for prana. Inside the body there are five major kinds of prana, or vayus, and five minor ones. The major vayus are:
Prana the upward lifting energy. This can be confusing; the vayu prana is a subset of the overall term for all energies, also called prana. The vayu prana is responsible for the energy of the heart and the breath. When we see a tree’s branches reaching upward to the sun, that is prana energy being expressed. When we feel our inhalations lift our spirit, along with our shoulders, that too is prana.
- Apana the downward, rooting energy. Apana is responsible for elimination, both through the lungs (eliminating carbon dioxide) and the digestive tracts. The roots of a tree searching downward for stability are expressing apana. The rooting downward of our exhalations tap into the same energy.
- Udana the “up breath” or upward moving energy. Udana is responsible for producing sounds and is the energy of the five senses. Some texts place this only in the throat but other texts say that it circulates in all the limbs and in the joints.
- Samana the balancing energy. Samana is responsible for digestion and the metabolism of our cells.
- Vyana the outward moving energy. Vyana is responsible for the movement of our muscles and for balancing the energy flow throughout our body.
None of these energies exist in isolation. One of the challenges in our yoga practice is to detect the presence of all these energies when one of them is most obvious. For example – take a deep breath. The energy of prana is obvious, but can you detect at the same time the subtle rooting energy of apana? More simply put, can you feel the apana in the prana? Try this on the exhalation too. Can you feel the prana in the apana? It may be useful to follow the movement of your diaphragm as you try this. On inhalations, despite the obvious lifting upward of the chest and shoulders, the diaphragm is descending. Following this movement may help you find the apana in the prana and vice versa. Once you can do this for the breath while sitting, try following these energies while you do your asana practice.
Sensing the flow of energy is a meditation practice all on its own. Just sitting for a few minutes watching the apana in the prana and the prana in the apana requires attention. Any time we follow our energies, we are meditating.
The five minor pranas are not important unless the student is going into advanced practices. This is fortunate as different sages describe different and conflicting effects of these minor energies. A generalization of these energies is compiled below, but the reader is warned that some teachers have very different observations:
- Naga causes salivation and hiccups
- Kurma causes opening of the eyes and blinking
- Krikara causes sneezing and sensation of hunger
- Devadatta causes yawning and sleep
- Dhanamjaya pervades the entire body; causes hair growth and lingers even after death.
Energy does not just simply exist; it flows. Just as our nerves channel electrical energy and our blood vessels channel chemical energy, so too prana is channeled in our bodies. These channels are known as nadis.