Effects of brief remote high ventilation breathwork with retention on mental health and wellbeing: a randomised placebo-controlled trial.

High ventilation breathwork with retention (HVBR) has been growing in popularity over the past decade and might be beneficial for mental and physical health. However, little research has explored the potential therapeutic effects of brief, remotely delivered HVBR and the tolerability profile of this technique. Accordingly, we investigated the effects of a fully-automated HVBR protocol, along with its tolerability, when delivered remotely in a brief format. This study (NCT06064474) was the largest blinded randomised-controlled trial on HVBR to date in which 200 young, healthy adults balanced for gender were randomly allocated in blocks of 2 by remote software to 3 weeks of 20 min daily HVBR (fast breathing with long breath holds) or a placebo HVBR comparator (15 breaths/min with short breath holds). The trial was concealed as a 'fast breathwork' study wherein both intervention and comparator were masked, and only ~ 40% guessed their group assignment with no difference in accuracy between groups. Both groups reported analogous credibility and expectancy of benefit, subjective adherence, positive sentiment, along with short- and long-term tolerability. At post-intervention (primary timepoint) for stress level (primary outcome), we found no significant group × time interaction, F(1,180) = 1.98, p = 0.16, η