Research paper · RP12

Six Breaths a Minute

Slow-paced breathing is a countable daily practice, not a personality change. The last published random-effects pool of breathwork versus control for self-reported stress was Hedges g = -0.35 (95% CI -0.55 to -0.14) from 12 randomised trials and 785 adults. That figure comes from Fincham and colleagues, search closed February 2022. This paper updates that review, and Laborde’s 2022 heart-rate-variability (HRV) review, with trials published through September 2026. The question is narrow. In non-clinical adults, and in employed samples where they exist, how large is the effect of paced breathing at ten breaths a minute or fewer, and what is the shortest session that still works? We searched PubMed, PsycINFO, Scopus, Web of Science, Google Scholar, CTRI, ClinicalTrials.gov and OSF. Eligibility was restricted to non-clinical adults, paced breathing at <=10 breaths per minute with or without HRV biofeedback, any control, and outcomes of perceived stress, HRV or mood. A de-novo study-level re-pool of only employed, non-clinical samples with complete extractable means and standard deviations is not yet possible without inventing numbers. We therefore report the published pools, then narrate the 2023-2026 trials that change how those pools should be read. The largest subsequent trial, Fincham, Strauss and Cavanagh 2023, randomised 400 adults to coherent breathing at about 5.5 breaths per minute or a matched 12-breath placebo, ten minutes a day for four weeks. The group-by-time effect on stress was etap2 < 0.001. Both arms improved. Against a well-matched paced control, the extra calm of “six breaths a minute” is not demonstrated. Against wait-list or usual care, earlier small-to-medium effects remain. During the practice itself, vagally indexed HRV rises with a medium effect (Laborde g = 0.53 for RMSSD). After multi-week programmes the resting-HRV rise is small and unstable (g = 0.32; several newer trials found no resting change). Five minutes is the floor for a useful session. Ten minutes a day for four weeks is the best-tested daily dose. No published randomised trial of isolated slow-paced breathing in Indian working professionals could be verified. Certainty for questionnaire stress in working adults is low to moderate. A null against an active placebo is a result, not a failure of the file.