Biohacking Methods

Cyclic Sighing

The double-inhale, long-exhale breathing pattern, tested against mindfulness in a Stanford randomised trial.

Cyclic sighing is a breathing exercise built on the physiological sigh: two inhales through the nose — one full, one short top-up — followed by a long, slow exhale through the mouth, repeated for about five minutes.

What published research reports

A randomised controlled study from Stanford published in Cell Reports Medicine (2023) compared five minutes daily of cyclic sighing, box breathing, cyclic hyperventilation and mindfulness meditation over one month in 108 participants. All groups improved, but cyclic sighing produced the greatest increase in daily positive mood and a significant reduction in resting respiratory rate, outperforming mindfulness meditation on mood measures. The authors report that exhale-emphasised slow breathing engages the parasympathetic “brake” on physiological arousal, and that effects grew with more days of practice.