Vayu — wind. Prana — in its broadest sense, the vital principle; in its narrower sense, one of five.
The model is straightforward: one prana, five functions, each with a direction, a seat and a domain. Understanding it is the single most useful thing in the subtle body material, because it is what makes the bandhas and pranayama legible.
A practitioner who does not have this model is being told to seal something they cannot name so that two things they have not heard of will meet.
The Five
Prana vayu — inward and upward. Seated in the chest and the region of the heart and lungs. Governs inhalation, reception, and the taking in of anything — air, food, sensation, impression. The upward-moving one.
Apana vayu — downward and outward. Seated in the pelvis, below the navel. Governs exhalation and everything eliminative and downward: excretion, urination, menstruation, birth. The downward-moving one.
Samana vayu — equalising, balancing. Seated at the navel. Governs digestion and assimilation, and the sorting of what has been taken in. Its movement is inward toward the centre.
Udana vayu — upward. Seated in the throat and head. Governs speech, expression, upward movement, and in the texts, the movement of consciousness at death. The one associated with growth and with what rises.
Vyana vayu — pervading. Seated throughout the body rather than in one place. Governs circulation and distribution — the movement of everything to everywhere. Coordinates the other four.
Notice the structure. Two opposed directions (prana up, apana down), one centralising (samana), one ascending beyond (udana), one pervading (vyana). It is a functional taxonomy of movement, not a description of substances.
Why Prana and Apana Matter Most
The practical core of the model, and the reason the bandha material takes the form it does.
They move in opposite directions and away from each other. Prana rises, apana descends, and in the ordinary state they disperse — one escaping upward, one downward.
The stated aim is to make them meet. The texts describe drawing apana upward and prana downward so that they unite at the navel or below, and this union is what generates the heat that rouses kundalini.
Every bandha follows from this. Mula bandha seals below and reverses apana's descent. Jalandhara seals above and prevents prana's escape. Uddiyana draws upward in the middle. The three locks are one action described three times — containing the two winds so they cannot disperse.
And retention is what creates the conditions. With the breath held, neither wind has its usual route out, which is why the bandhas are applied during kumbhaka rather than while moving — the argument in the three locks.
This is the whole logic, and it is coherent. It is also the thing modern teaching leaves out, which is why "engage mula bandha" survives as an instruction with no stated purpose.
The Directions, and Why They Are the Substance
Worth dwelling on, because the directional scheme is doing more work than the seats and domains.
Two opposed. Prana up, apana down. This is the axis everything else is organised around, and it is the one the practices act on.
One centralising. Samana draws inward to the navel — the sorting function, taking what has come in and distributing it.
One transcending. Udana continues upward past the throat, and it is the one associated in the texts with what leaves at death.
One pervading. Vyana has no direction because it is everywhere, coordinating the rest.
Read as a diagram rather than a list, the model is a vertical axis with two opposed flows, a centre, an exit above, and a field surrounding all of it. That is a compact and rather elegant account of how a body organises movement, and it explains why the practices are so concerned with the vertical.
It also explains the seats. Chest, pelvis, navel, throat — these are not organs but the regions the directions are anchored to, and the bandhas are placed at exactly the transitions between them. Jalandhara at the throat, where udana leaves. Uddiyana at the navel, where samana centres. Mula at the base, where apana descends.
Which is the point worth taking: the three locks are placed where they are because of this diagram. Nothing about the anatomy explains why those three sites; the vayu model explains it completely.
What the Sources Say
The model is older than hatha yoga. The vayus appear in the Upanishads, and the five-fold scheme is well established in the Vedantic literature before the hatha texts adopt it. The Prashna Upanishad discusses prana and its divisions at length.
Ayurveda uses the same scheme, with the vayus as subdivisions of vata dosha, and applies it to physiology and pathology in its own terms.
The hatha texts assume it rather than expounding it. The Hatha Yoga Pradipika refers to prana and apana constantly and does not stop to explain the five-fold model, which tells you the framework was taken as known.
And the number varies. Five principal vayus is standard; the minor or upa vayus — naga, kurma, krikara, devadatta, dhananjaya — are given as five more, with some variation in the lists.
How to read all this. It is a framework with a long, consistent history across several Indian systems. It is not a description of substances moving in channels, and translating prana into oxygen or the vayus into autonomic functions is a modern move rather than a reading — the general point is in the subtle body.
Using It Without Believing It
The practical section, because the model is useful whatever your view of its status.
It is a vocabulary for felt experience. "Apana feels heavy today" is a compact way of describing a downward, sluggish, eliminative quality that English has no single word for. That is what a phenomenological vocabulary is for, and it does not require anything to exist.
It explains why the practices are shaped as they are. A student who knows the prana-apana account understands immediately why the bandhas are applied on retention, why they are three rather than one, and why inversions are grouped with them. Without it, none of that is legible.
It gives a coherent account of the tradition's priorities. Why so much emphasis on the pelvic floor and the throat, why exhalation is treated as significant, why the navel keeps appearing — these follow from the model.
And it is testable in the only sense that matters here: does using the vocabulary help you notice things? For many practitioners it does, and that is a modest and defensible claim.
What not to do. Do not assign vayus to organ systems. Do not diagnose. Do not tell a student their apana is disturbed. The moment the model is used to make claims about a person's body, it has been converted into bad physiology.
The Modern Mappings to Avoid
Prana as oxygen. The most common, and it fails immediately — apana would have to be carbon dioxide, samana digestion, and the scheme collapses.
The vayus as autonomic functions. Occasionally proposed and it does not fit; the five do not map onto sympathetic and parasympathetic divisions in any consistent way.
Vayus as specific organ systems. Samana is not the digestive system. It is described as governing digestion, which is a functional attribution within a framework, not an identification.
Apana as the pelvic floor. A common shorthand in yoga teaching and a category error — apana is a described direction of movement, and the pelvic floor is a muscle group.
The general test: if a statement about the vayus could be checked with a scan, it has been translated rather than reported.
Where the Vayus Turn Up in Practice
In the bandhas, as above — the entire rationale.
In pranayama, where the practice is described as regulating prana with the breath as the handle rather than as a breathing exercise.
In the names. Apana in Apanasana, the knees-to-chest posture, named for the downward wind it is said to assist. Prana throughout.
In sequencing logic. Grounding practices are described as working with apana, energising ones with prana, and this is the framework behind a great deal of teaching language that otherwise floats free.
And in the mudra material, where viparita karani reverses the ordinary direction of the winds by inverting the body — the connection set out in jalandhara bandha.
The Five Minor Winds
Included briefly, since they are usually listed and rarely explained, and they are covered in full separately.
Naga — governs belching and hiccup.
Kurma — governs blinking and the opening and closing of the eyes.
Krikara — governs sneezing, coughing and the sensation of hunger and thirst.
Devadatta — governs yawning and stretching.
Dhananjaya — described as remaining in the body after death, and associated with decomposition.
The lists vary between sources, and the functions assigned shift somewhat, which is worth noting rather than presenting one version as definitive.
What is interesting about them is what kind of thing they are. These are involuntary, reflexive, slightly odd bodily events — the ones that happen to you rather than being done. The framework has a category for exactly that, which is a more thoughtful piece of taxonomy than it first appears.
They have almost no practical application in the practices, unlike the five principal vayus, and they are best understood as the model being thorough rather than as something to work with.
Frequently Asked Questions
What are the five prana vayus?
Prana (inward and upward, chest), apana (downward and outward, pelvis), samana (equalising, navel), udana (upward, throat and head) and vyana (pervading, throughout). One prana with five functions.
What is the difference between prana and prana vayu?
Prana in the broad sense is the vital principle as a whole. Prana vayu is one of its five divisions — the specific inward and upward movement seated in the chest. The word does double duty, which causes some confusion.
What is apana?
The downward and outward movement, seated below the navel, governing exhalation and everything eliminative. In the practices it is the wind the bandhas are meant to reverse.
Why do prana and apana need to meet?
Because in the ordinary state they move apart and disperse. The texts describe uniting them as generating the heat that rouses kundalini, and every bandha is a way of preventing their escape so that they can.
Is prana the same as oxygen?
No, and the equivalence fails as soon as you extend it — apana would have to be carbon dioxide and samana would have to be digestion. It is a modern translation rather than a reading of the sources.
Are the vayus part of the nervous system?
No. They do not map onto sympathetic and parasympathetic divisions in any consistent way, and proposals to the contrary are modern reinterpretations rather than translations.
Where does the vayu model come from?
It is older than hatha yoga. The five-fold scheme appears in the Upanishads and is well established in Vedantic literature, and Ayurveda uses the same divisions as subdivisions of vata. The hatha texts assume it rather than explaining it.
What are the upa vayus?
Five minor winds — naga, kurma, krikara, devadatta and dhananjaya — governing functions like belching, blinking, sneezing, yawning and what remains after death. The lists vary between sources.
Is the vayu model useful if I don't believe in prana?
Yes, in two ways. It is a compact vocabulary for qualities of felt experience that English does not name well, and it explains why the practices take the form they do — which makes the bandhas and pranayama legible rather than arbitrary.
The Model That Makes the Practices Legible
Five directions of movement, two of them opposed, and a set of practices designed to stop them dispersing. That is the whole of it, and it is the missing piece for anyone who has been told to engage a lock with no explanation of what it is locking or why. Whether the winds exist is a separate question from whether the model explains the tradition — and it does, completely.
Rohit Yoga Academy's residential 200-hour Yoga Teacher Training in Swargashram, Rishikesh teaches the subtle body framework alongside the practices it explains, in groups capped at fifteen.