In the study comparing sighing, breathwork, and mindfulness meditation, the sighing group — who performed something called cyclic sighing — was told to inhale through the nose slowly, then inhale a little more to fill the lungs, then sigh out through the mouth. The box breathing group inhaled for a specific number of seconds, held the breath for that same duration, exhaled the same duration, and then held the breath for an equal duration. The cyclic hyperventilation group was instructed to breathe in deep through the nose then allow the air to fall out of the mouth and repeat 30 times. After the 30th breath, they paused at the end of the exhale for 15 seconds, then resumed the 30-breath set for two more rounds. The mindfulness meditation group focused on a point on their forehead between their eyebrows for five minutes.
After each breath practice or mindfulness meditation, participants felt that their positive feelings improved and their negative emotions had reduced. They also felt less anxious after their five-minute practices. The three groups that practiced breathwork had reduced their respiratory rate more than the mindfulness group.
What's more, the sighing group had better improvements in feeling positive over the month-long practice. In other words, as that group practiced their cycling sighing each day, their positive emotions continued to increase. This wasn't the case with the other breath practice groups or the mindfulness group.
