Decreased CO2 during breathwork: emergence of altered states of consciousness

I've had this described to me as basically the combination of neuro+psychological effects of hyperventilation (respiratory alkalosis) in a peaceful/positive environment (as opposed to anxiety-attack-driven or etc.), plus the meditative effects of deep breathing, plus the meditative/brain-entrainment effects of rhythmic movement of a major central/core muscle (diaphragm). Together, those often cause euphoria, altered states of consciousness, and cognitive shifts not too far off from psychedelics.

Could someone who is more familiar with it affirm, adjust, or deny that as a general (medically-grounded/secular) summary of breathwork?

I've experimented with holotropic breathwork, and was quite amazed at the experience. Unfortunately, as much as I've tried to re-create the experience while not lead, I find my mind just doesn't want to go beyond about 5-10 minutes of breathing, vs the 30 minutes I did in breathwork sessions.

Having said that, I think the design of this study could be much improved. It shouldn't be too difficult to create a double blind group environment using headphones (think like a silent disco) where both participants and researchers don't know who is listening to guided or not.

I'm also not sure if the biomarkers are the best. DMT can apparently be detected in saliva, and I believe the theory is that during holotropic breathwork, the pineal gland releases more DMT than normal.

I wonder if there's a vagal nerve effect from the increased chest pressure while holding your breath in.

I do the 'double sharp inhale' method for the anxiolytic effect occasionally - not really something you can do at the office however.

" find my mind just doesn't want to go beyond about 5-10 minutes of breathing, vs the 30 minutes I did in breathwork sessions."

Same for me. I did a workshop with Wim Hof and the breathing exercises were great with really profound effects. But I couldn't make myself practicing at home with the same intensity regularly. I also developed a pretty bad cough after a few weeks. Probably from the dry air where I live.

I hate getting startled, even when I realize right away that there is nothing to worry about. But the physiological effects, once set in motion, carry on. My heart seems to skip a beat and then rev up to a high rate and it's uncomfortable, taking some time to come back down to normal.

Some years ago, I discovered a technique to suppress the effect of being startled. I just breathe in sharply, using mostly my diagphragm, before my heartrate goes up and it keeps things normal as usual. I wonder if this is also using the vagus nerve to suppress being startled?