Like some other breathing techniques, the method behind box breathing revolves around counting the span of your breaths. If you want to give it a try, close your eyes and do the following. First, take a deep inhale while counting to four. Hold that breath for another four seconds, then exhale through your mouth — also on a count of four. Finally, wait four seconds with your lungs empty before taking your next inhalation, then repeat the cycle (via Anahana). In other words, breathe in for four, hold for four, breathe out for four, and hold for four again. Try this pattern for five minutes, or however long feels right to you.
If four seconds feels too challenging, you can start by doing each count for two or three seconds and working your way up as your lung capacity improves. Or, on the reverse, you can also extend this timing up to eight seconds per step. Ultimately, the length of time you use is less important than the rhythm and mindfulness inherent to the pattern of box breathing.
As Dr. Young says, "It allows you to slow your breath, and it also has an aspect of meditation. As you're breathing, you're also silently counting, which is a kind of mantra meditation that, again, calms the nervous system and brings you into the present moment."