“Box breathing is a technique that helps you take control of your automatic breathing patterns to train your breath for optimal health and performance,” says Mark Divine, former US Navy SEALs Commander, NYT bestselling author of The Way of the SEAL and founder of SEALFIT. “It combines the practice of optimal breathing with para-sympathetic activation, concentration and mindfulness training,” he adds.

All you need to do is picture a box with equal sides, where the inhale, the holding of the breath, and exhale are all four counts (four seconds approx.). “As you take in a breath, for four counts, visualize traveling up one side of the square. Next, imagine moving across the top of the square during the four counts of holding your breath. Then follow the breath down the right side of the box on the exhale and watch it travel across the bottom of the square on the breath hold, following the exhale. Repeat the pattern,” says Dr. Symington.

“This visual provides a helpful anchor for your attention and quickly allows you to get into the flow of rhythmic breathing,” adds the clinical psychologist.

When we box breathe, we do so through our nostrils. “This helps us draw the air deep into our lungs, slowing down the breathing rhythm and stimulating the vagal nerve – which runs throughout the central nervous system,” says Divine. The vagal nerve affects heart rate, digestion and releases neurotransmitters that activate the parasympathetic nervous system (PSNS). “The calming and focusing effects of this technique are noticeable within just a few minutes of practice,” he points out.

To better understand this technique, contrast the box breath with what happens during a panic attack. Your body goes full-on ‘fight or flight’ with fast, shallow breathing and pounding heart. “It signals your brain to panic which signals your body to breathe even more shallowly and your heart to beat even faster,” tells Everatt. “The deep conscious breath of the box breath is the opposite of panic. It’s a relaxation response that you can trigger at any place, any time,” says the wellness expert.

“Box breathing allowed me to perform exceedingly well in the SEALs,” says Divine.

“It was instrumental in saving my life several times in crises,” says Divine. “I was able to remain calm and focus clearly to avoid reactionary thinking, or worse, panic,” tells the former Navy SEAL. “I also used the practice to extend my dive duration when using a closed-circuit re-breather – from the customary four hours to nearly five,” he adds.

This is why, in 2006, Divine began teaching this technique to other SEAL and Special Ops candidates as well – through his fitness and training program, SEALFIT. Now, the Basic Underwater Demolition-SEAL and Air Force Pararescue training commands are bringing the practice into their military training programs, he tells.

So, are you ready to try it out yourself? Good! Here’s a step-by-step guide on how to box breathe correctly:

• Start by sitting with your spine as straight as possible.
• Close your mouth and eyes. And exhale all of the air out of your lungs.
• Next, inhale slowly through your nose, counting 1-2-3-4.
• Now close the valve at the back of your throat and hold your breath for that same count. “When you do this, keep a slight lifting sensation as opposed to clamping down, causing pressure on your heart and lungs,” Divine suggests.
• Next, exhale slowly through your nose to that same count. Hold your breath again after the exhale.

“If you feel agitated at all on the exhale hold, you can shorten it to a two or three count. If four count is easy, consider doing it for five or six counts,” Divine recommends. “Unless you are doing this to extend your breath hold duration as well – for spearfishing or SEAL training – there is no significant benefit to doing more than a six-count hold,” he points out.