Intervention
The intervention group received CB at ~ 5.5 bcpm (with equal inhale/exhale durations of ~ 5.5 s each), pre-recorded and guided by a trained breathwork facilitator from the organisation Othership (othership.us). Participants were asked to practise their randomly allocated breathwork session daily for four weeks: ~ 10 min/day for 28 days. The average cadence for teaching coherent breathing in the general population is around 5–6 bcpm, hence 5.5 bcpm was chosen for the intervention. The duration of ~ 10 min was deemed as a manageable time for participants, and several studies (ranging from days to weeks) on meditation have suggested benefit can be derived from this short length of practiseAt the start of the breathwork sessions, to get participants ready for the paced breathing, they were instructed to sit up straight or lie down in a quiet place with no disturbances, eyes closed or gaze lowered with headphones on. They were then instructed to soften their face, neck and shoulder muscles and take two deep breaths into the abdomen/diaphragm and let each one go with a sigh, softening the whole body. In order to control for as much variation as possible among participants’ respiration patterns and styles, throughout the paced breathing they were instructed to breathe softly and gently through the nose and abdominally/diaphragmatically in a balanced, rhythmic way. At the end, participants were instructed to resume normal breathing and take a moment to tune into how they felt. No loaded language pertaining to the speed of the breathing was used, nor how participants were supposed to experience the breathwork.