Comparator
The placebo control was matched to the active intervention in all domains but pace of breathing. This group received attention-placebo CB at 12 bcpm (with equal inhale/exhale durations of 2.5 s each) recorded by the same breathwork facilitator as for the intervention. This metric was chosen in line with guidance from the Royal College of Physicians, British Journal of Nursing and Johns Hopkins University which state that the average, healthy bcpm ranges from: 12–20, 12–18 and 12–16 at rest, respectively