The Supramentalised state of existence involves a completely different state of physical bodily consciousness. Unlike most other yogas and realisations, which involve discarding or transcending the physical, the Supramental Yoga involves the Divinization of the very body itself. There is already the beginnings of this in Tantra and in the practice of Taoist Internal Alchemy, both of which are incredibly profound by the standards of ordinary everyday consciousness, full of light and shakti and bliss, but Mirra's (the Mother's) experiences are of an even higher order again. The following text illustrates this:
From the Agenda, January 24, 1961:
In the middle of the night before last, I woke up (or rather I returned to an external consciousness) with the feeling of having a much larger (by larger I mean more voluminous) and much more powerful being in my body than I usually have. it was as if it could scarcely be held inside me but was spilling over; and SO COMPACTLY POWERFUL that it was almost uncomfortable. The feeling of: what to do with all this?
It lasted the remainder of the night and all day long I had considerable trouble containing an overwhelming power that spontaneously created reactions utterly disproportionate to a human body and made me speak in a way that.... When something was not going well: wham! Such an instantaneous and strong reply that it looked like anger. And I found it difficult to control the movement - it had happened already in the morning and it very nearly happened again in the afternoon. 'That last attack has weakened me terribly!' I told myself, I don't have the strength to contain this Power; it's difficult to remain calm and controlled.' That was my first thought, so I insisted upon calm.
Then yesterday afternoon, when I went upstairs to walk,  a couple of things occurred - not personal, but of a general nature - concerning, for instance, certain old-fashioned conventions having to do with women and their particular nature (not psychological, physical) - old ideas like that which had always seemed utterly stupid to me suddenly provoked a kind of reprobation completely out of proportion to the fact itself. Then one or two other things  happened in regard to certain people, certain circumstances (nothing to do with me personally: it came from here and there). Then suddenly, I saw a Force coming ('coming,' well, 'manifesting') which was the same as that 'thing' I had felt within me but even bigger; it began whirling upon the earth and within circumstances ... oh, like a cyclone of compact power moving forward with the intention of changing all this! It had to change. At all costs, it must change!
I was above, as usual (Mother points above her head, indicating the higher consciousness), and I looked at that (Mother bends over, as if looking down at the earth), and said to myself, 'Hmm, this is getting dangerous. If it continues like this, it will result in ... in a war or a revolution or some catastrophe - a tidal wave or an earthquake.' So I tried to counteract it by applying the highest consciousness to it, that of a perfect serenity. And I saw especially that this consciousness has been missioned to transform the earth through the Supermind and by the supramental Force, avoiding all catastrophes as far as possible: the Work is to be done as luminously and harmoniously as the earth would allow, even by going at a slower pace if need be. That was the idea. And I tried to counteract that whirlwind power with this consciousness.
I must say that after this, when I read The Secret of the Veda as I do each evening.... In fact, I am in very close contact with the entire Vedic world since I've been reading that book: I see beings, hear phrases.... It comes up in a sort of subliminal consciousness, a lot of things are from the ancient Vedic tradition. (By the way, I have even come to see that the pink marble bathtub I told you about last time, which Nature had offered me, belongs to the Vedic world, to a civilization of that epoch. ) There were - there are always - Sanskrit words coming up, sentences, bits of dialogue.... This is of interest, because I realized that what I had seen the other day (I told you about it) and then what I saw yesterday - that whole domain - was connected to what the Vedas call the dasyus - the panis and the dasyus  - the enemies of the Light. And this Force that came was very clearly a power like Indra's  (though something far, far greater), and at war with darkness everywhere, like this (Mother sketches in space a whirling force touching points here and there throughout the world), this Force attacked all darkness: ideas, people, movements, events, whatever made stains, patches of shadow. And it kept on going, a formidable power, so great that my hands were like this (Mother clenches her fists). Later when I read (I happened to be reading just the chapter concerning the fight against the dasyus), this proximity to my own experience became interesting, for it was not at all intellectual or mental - there was no idea, no thought involved.
The remainder of the evening passed as usual. I went to bed, and at exactly a quarter to twelve I got up with the feeling that this 'presence' in me had increased even further and really become rather formidable.... I had to instill a great deal of peace and confidence into my body, which felt as though ... it wasn't so easy to bear. So I concentrated, I told my body to be calm and to let itself go completely.
At midnight I was lying in bed. (And I remained there from midnight until I o'clock fully awake. I don't know if my eyes were open or closed, but I was wide awake, NOT IN TRANCE - I could hear all the noises, the clocks, and so forth.) Then, lying flat, my entire body (but a slightly enlarged body, exceeding the purely physical form) became ONE vibration, extremely rapid and intense but immobile. I don't know how to explain this, because it did not move in space but was a vibration (that is, it wasn't motionless); yet it was motionless in space. And the exact form of my body was absolutely the most brilliant white Light of the supreme Consciousness, the consciousness OF the Supreme. It was IN the body and it was as though in EACH cell there was a vibration, and it was all part of a single BLOCK of vibration. It extended this much beyond the body (gesture indicating about six centimeters). I was absolutely immobile in my bed. Then, WITHOUT MOVING, without shifting, it began consciously to rise up - without moving, you understand: I remained like this (Mother holds her two joined and motionless hands at the level of her forehead, as if her entire body were mounting in prayer) - consciously ... like an ascension of this consciousness [The body-consciousness. ] towards the supreme Consciousness.
The body was stretched out flat.
And for a quarter of an hour, the consciousness rose, rose, without moving. It kept rising up, up, up - until ... the junction was made.
A conscious junction, absolutely awake, NO TRANCE.
Thus the consciousness became the ONE Consciousness: perfect, eternal, outside time, outside space, outside movement ... beyond everything, in ... I don't know, in an ecstasy, a beatitude, something ineffable.
It was the consciousness OF THE BODY.
I have had this experience before in exteriorization and trance, but this time it was THE BODY, the consciousness of the body.
It remained like that for a certain time (I knew it was a quarter of an hour because the clock chimed), but it was completely outside time. It was an eternity.
Then, with the same precision, the same calm, the same deliberate, clear and concentrated consciousness (absolutely NOTHING MENTAL), I began to come back down. And as I was descending, I realized that all the difficulty I had been fighting the other day and which had created this illness was absolutely ended, ANNULLED - mastered. Actually, it was not even mastery but the non-existence of anything to be mastered: Simply THE vibration from top to bottom; yet there was neither high nor low nor any direction.
And it went on like that. After this, Slowly, Still WITHOUT MOVING, everything went back into each of the different centers of the being. (Ah, let me say parenthetically that it wasn't AT ALL the ascent of a force like the ascent of the Kundalini! It had absolutely nothing to do with the Kundalini movement and the centers, it wasn't that at all.) But while re-descending, it was as though WITHOUT LEAVING THIS STATE, without leaving this state which remained conscious ALL the time, this supreme Consciousness began to reactivate the different centers: first here (Mother points to the center above the head and then touches the crown of the head, the forehead, throat, chest, etc.) then there, there, there. At each there was a pause while this new realization organized everything. It organized and made the necessary decisions, sometimes down to the most minute details: what had to be done in this case or said in that case; and all of that TOGETHER, at once, not one by one but seen entirely as a whole. It kept on descending - I noted many things, it was extremely interesting - down and down, farther and farther, right to the depths. Everything went on at the same time, [Later, Mother added: 'All the experiences took place one after the other, but the new experience did not cancel the preceding one. The Consciousness - this supreme Unity that I had - remained all the time, to the very end, even while the other centers were awakening. And each center that awakened was a kind of addition, taking away nothing from what had come before. So at the end it was all simultaneous: a kind of global consciousness - total and simultaneous - of everything.... You see, while rising up (one is obliged to say "rising" and "descending" for otherwise one would never be understood), while "rising up" to reach this supreme Consciousness, all the rest was annulled, there was only That. When the supreme Consciousness was realized, it remained ALL the time, continuously, to the very end, it did not move; but meanwhile, the other centers began to awaken one after another. And each awakening center assumed its place but canceled nothing either of what had come before or of what was about to come, so that when I reached the end, all of it together was a simultaneous whole - the Supreme Consciousness.' When Satprem asked if this Supreme Consciousness was the 'New Consciousness,' Mother replied, 'Not "new!" One can't say "new" - Supreme Consciousness.' ] simultaneously, and at the same time this supreme Consciousness was organizing everything separately. 
This descending reorganization ended exactly when the clock struck one. At that moment I knew that I had to go into trance for the work to be perfected, but until then I was wide awake.
So I slipped into trance.
I came out of this trance two hours later, at 3 a.m. And during these two hours I saw ... with a new consciousness, a new vision, and above all a NEW POWER - I had a vision of the entire Work: all the people, all the things, all the systems, all of it. And it was ... it was different in appearance (this is only because appearances depend upon the needs of the moment), but mainly it differed IN POWER - A considerable difference. Considerable. The power itself was no longer the same. [Later, Mother added: 'The Power that was acting was no longer the power that had been acting previously.' ]
A truly ESSENTIAL change in the body has occurred.
I see that the body will have to - how can I express it? ... It will have to accustom itself to this new Power. But essentially the change has been accomplished.
It's not ... it is far, very far from being the final change, there's a lot more to be done. But we may say that it's the conscious and total presence of the supramental Force in the body.
When I got up today, I was going over all this to myself, and my first instinct was not to speak of it, to observe and see what would happen; but then I received a distinct and precise Command to tell it to you this morning. The experience had to be noted down just as it occurred, recorded in its exact form.
In the body now, there is a very clear ... not only a certitude, but a feeling that a certain omnipotence is not far away, and that very soon when it sees ('it' sees ... 'it'! There is only one 'It' in this whole affair, which is neither 'he' nor 'she' nor ... ), when it sees that something must be, it automatically will be.
There is still a long, long way to go. But the first step on the way has been taken.
Footnotes: (by Satprem)
1. Mother did her japa (mantra) while walking back and forth in her room.
2. Satprem later asked Mother what she meant by these 'things,' and Mother replied: 'For example, there was a certain man's attitude with respect to life and to the Divine, and what he thought of himself, and so forth. You see, what came was a whole range of characters and one particular action of one man, and then something else came up.... How to explain? ... These are POINTS OF WORK which come to me, things that present themselves in the atmosphere for me to see - things I see and which have to be acted upon.'
3. A few days later, Mother rectified: 'I have looked at the experience again and realized that it's not Vedic but pre-Vedic. The experience put me into contact with a civilization prior to the Vedas - the Rishis and the Vedas are a kind of transition between that vanished civilization and the Indian civilization which grew out of the Vedic Age. It was yesterday [January 26] that I perceived this, and it was quite interesting.'
(MAK: this theme of a civilization "prior to the Chaldeans and the Vedas" the Mother first acquired during her time with Theon (who calimed access to this Tradition), although she refers to past incarnations which seem to date to this period. It may be equivalent to Atlantis)
4. In the Vedas, the panis and dasyus represent beings or forces hidden in subterranean caves who have stolen the 'Riches' or the 'Lights', symbolized by herds of cows. With the help of the gods, the Aryan warrior must recover these lost riches, the 'sun in the darkness,' by igniting the flame of sacrifice. It is the path of subterranean descent.
5. Indra represents the king of the gods, the master of mental power freed from the limitations and obscurities of the physical consciousness
6. This entire experience and Mother's insistence that it all happened 'without moving,' unlike the experience of the ascent of the Kundalini, suggests that it is the supramental consciousness concealed in the depths of the cells, that somehow emerges and traverses all the layers until the junction is made with the most material body-consciousness.