Practice the physiological sigh—a double quick inhale through the nose followed by a long exhale through the mouth—to instantly calm the heart rate and diffuse stress.

noli's read

This breathing reflex is based on solid scientific foundations, notably validated by a randomized controlled trial (RCT) led by the team of Melis Yilmaz Balban and David Spiegel at Stanford University, published in Cell Reports Medicine in 2023. This high-quality study compared several breathing exercises over one month and proved that this 5-minute daily 'cyclic sighing' is the most effective for improving mood and calming the mind. Physically, the double inhale allows for maximum opening of the small air sacs in our lungs, which helps to efficiently expel accumulated carbon dioxide during the long exhale. By exhaling slowly, one naturally signals our body's relaxation system to activate, which allows for a gentle slowing of the heart rate. The claim of an instant effect is accurate, as a single sigh immediately triggers this calming reflex, even if research shows that repeating the exercise for a few minutes provides much more lasting benefits for tension management. It is a perfectly rigorous and accessible piece of advice, ideal for regaining one's balance in a few seconds.

the sources

1. 1NIH Office of Dietary Supplements 2026
2. 2Manson JE et al. 2019
3. 3Bhatt DL et al. 2019
4. 4Khan SU, Lone AN, Khan MS, et al. 2021
5. 5Liao Y, Xie B, Zhang H, et al. 2019
6. 6hubermanprotocols.com (fan reference guide)