Box Breathing is a spiritual tool I first discovered in the book, Rising Strong by Brené Brown. It can calm the fight or flight response, aid emotional regulation (particularly around anxiety and stress), and center us in the present moment.
I personally use it as a quick-fix tool in stressful moments such as when I am sitting in my car following a difficult conversation with a hospice patient, and I recently taught it to the rest of my hospice team in a presentation about preventing Compassion Fatigue.
Beyond the awareness and emotional/spiritual effects, there is evidence that even a single session of breathing practices like this can create positive physical effects as well (like reducing blood pressure, and increasing heart rate variability and oxygenation)—so why not give it a try?
Inhale. Hold. Exhale. Hold. 4 seconds each, repeat.
Bernardi, Luciano, et al. “Effect of breathing rate on oxygen saturation and exercise performance in chronic heart failure.” The Lancet 351.9112 (1998): 1308-1311; Lehrer, Paul, et al. “Voluntarily produced increases in heart rate variability modulate autonomic effects of endotoxin induced systemic inflammation: an exploratory study.” Applied psychophysiology and biofeedback 35.4 (2010): 303-315; Ma, Xiao et al. “The Effect of Diaphragmatic Breathing on Attention, Negative Affect and Stress in Healthy Adults,” Frontiers in Psychology, vol. 8, 874. 6 June 2017, doi:10.3389/fpsyg.2017.00874; Wang, Shu-Zhen, et al. “Effect of slow abdominal breathing combined with biofeedback on blood pressure and heart rate variability in prehypertension.” The Journal of Alternative and Complementary Medicine 16.10 (2010): 1039-1045.