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