The discussion revolves around the effects of breathwork, particularly holotropic breathwork, on consciousness and CO2 levels. Users highlight personal experiences where long sessions lead to altered states, while short practices do not yield the same results. There are suggestions for improving research methodology, particularly regarding double-blind studies in breathwork contexts. Concerns over biomarker choices are raised, particularly with regards to measuring DMT release, which some believe is involved in these altered states of consciousness. The overall effects are described as a mix of neurological and psychological changes resulting in euphoric and transformative experiences, akin to those induced by psychedelics. The user comments call for a more medically-sound understanding of these phenomena.