“Here’s how to do it: First, sit down, get comfortable, and close your eyes. Make sure you’re in a position where you can freely expand your lungs. Wim suggests doing this practice right after waking up since your stomach is still empty. Warm up by inhaling deeply and drawing the breath in until you feel a slight pressure. Hold the breath for a moment before exhaling completely, pushing the air out as much as you can. Hold the exhalation for as long as you can, and then repeat this fifteen times. Next, inhale through your nose and exhale through your mouth in short, powerful bursts, as if you’re blowing up a balloon. Pull in your belly when you’re exhaling and let it expand when you inhale. Do this about thirty times, using a steady pace, until you feel that your body is saturated with oxygen. You may feel light-headed or tingly, or you may experience a surge of energy that’s literally electric. Try to get a sense of which parts of your body are overflowing with energy and which ones are lacking it—and where there are blockages between these two extremes. As you continue breathing, send the breath to those blockages. When you’re done, take one more big breath in, filling your lungs to maximum capacity, and then push all of the air out. Hold this for as long as you can and try to feel the oxygen spreading around your body. When you can’t hold it anymore, inhale fully and feel your chest expanding. Hold it again, sending energy where your body needs it. Bonus points if you do what Wim had me do when we demonstrated this technique onstage at our Bulletproof conference—as you are holding your lungs empty, count how many push-ups you can do before you have to breathe again. I got to twenty! It seems impossible, but you can do it, and that short bit of low oxygen forces your body to better deal with lower-oxygen environments. I recommend you research Wim’s work and watch one of his many videos online demonstrating his breathing technique. I don’t think it works as well as mechanically filtering oxygen out of the air you breathe, but the Wim Hof technique is absolutely free, totally portable, and Wim is capable of things I could never do! His breathing method helps your body adapt to bursts of oxygen and puts you more in tune with the way your body uses your breath to create energy. It also makes you more resilient to cold temperatures, but there is evidence that cold temperatures themselves are good for your mitochondria.”