For rapid anxiety relief I learned of this highly effective technique from Dr. Andrew Huberman. It takes only one to three reps and can be used in the moment of experiencing a heightened state of anxiety. Take a deep breath in, followed by a second rapid inhale, then an extended exhale.

Referred to as a physiological sigh, this technique maximizes the offloading of carbon dioxide. It has a calming effect in relation to heart rate variability. Just one to three repetitions of this method has been shown to be highly effective. This allows us to reduce stress in the moment, as it is occurring, without having to pause life or step away from the task at hand.

For a demonstration watch "Breathing Techniques to Reduce Stress and Anxiety | Dr. Andrew Huberman on the Physiological Sigh" interview with Tim Ferris. Since learning of this technique my stress level has greatly reduced overall. I hope this method brings you relief from anxiety with an experience of more calmness throughout your day.