Feeling stressed out? Want to know how to lower stress? In just a few minutes, you can restore calm with a simple technique known as “cyclic sighing.”

Researchers as Stanford Medicine say this controlled breathing exercise –which involves exhaling very slowly — can have positive effects in just five minutes, improving mood and decreasing rates of resting breathing. The latter is considered a sign of overall body calmness.

In a randomized, controlled trial, the researchers found that cyclic sighing was more effective in defusing anxiety than mindfulness meditation and other breathing techniques.

Typically, a stressful event causes the body to experience several physiological changes ranging from increased heart rate and quickened breathing to tightening muscles and sweaty armpits.

These physical symptoms can trigger anxious thoughts and fears, particularly for those with anxiety disorders.

Interventions such as cyclic sighing can break the pattern. Here’s how you do it:

1. Breathe in through the nose only until the lungs are comfortably full (about half full).
2. Take another, even deeper breath in through the nose, filling the lungs fully.
3. Very slowly exhale through your mouth until all the air is gone.

You can also hear study co-leader Dr. David Spiegel explain cyclic sighing, and see it demonstrated, in this Stanford Medicine video.

The researchers say you might notice a positive change after doing this just a couple of times, but you are more likely to get the full effect if you continue for five minutes.

Why cyclic sighing works

Why does it work? The researchers say the breathing exercise triggers your parasympathetic nervous system, which causes the heart rate to slow and creates a calming effect throughout your body.

In a summary of the findings, Spiegel — a professor of medicine and associate chair of psychiatry and behavioral sciences at Stanford Medicine — says:

“Most of the time breathing is automatic, like digestion, heartbeat and other bodily functions, but you can very easily take over and control your breath, which then affects your overall physiology and stress response.”

In the trial, cyclic sighing was found to be more effective than mindfulness meditation at boosting positive affect, which includes beneficial feelings such as energy, joy and a sense of peace.

The researchers note that in mindfulness meditation, practitioners are instructed to be aware of their breath. However, unlike with cyclic sighing, individuals are told to avoid trying to control their breath.

The researchers also found that cyclic sighing worked better than two other controlled breathing techniques in enhancing feelings of well-being:

• Cyclic hyperventilation — which emphasizes inhalation instead of exhalation
• Box breathing, also known as tactical breathing — which emphasizes breathing in and out for equal amounts of time, and is used by some military members to regulate stress and improve performance

Those who practice cyclic sighing typically find that their breathing is slower than those using all the other techniques, the researchers say. This impact continues throughout the day, “indicating a lasting effect on physiology,” Spiegel says.