Every number below is in the course with its sample size attached. Where a finding is preliminary, the lesson says preliminary.
Slow breathing47 healthy participants. Breathing at 5.5 a minute with an equal in-to-out ratio raised several heart-rate-variability measures and subjective relaxation. Lin et al., 2014.
Resonance17 studies, 810 participants. Broadly favourable psychological and physiological changes - alongside heterogeneous protocols and a stated need for more data. Vukojević et al., 2024.
Box breathing66 participants. Box breathing and prolonged exhalation both softened subjective anxiety and heart-rate rise before a stress test; HRV and cortisol did not separate. McAllister et al., 2026.
InteroceptionFour online sessions, 85% completion. The RISE programme improved noticing, not-worrying, self-regulation and body trust, holding at three months. Smith, 2023.
Panic38 participants, randomised. An interoceptive-exposure component beat breathing retraining on panic frequency and severity - with notable attrition in the follow-up.
Dose120 participants. Intense interoceptive exposure outperformed low-dose; some low-intensity variants were followed by more frequent fear sensitisation.
Uncertainty76 fMRI studies, meta-analysed. Especially consistent anterior-insula involvement under uncertainty - which is not the same as anxiety living in the insula.