“I’d gotten a fair share of gasps from friends when I told them about the experiment,” James Nestor recounts, in the first chapter of his most recent book, Breath. “‘Don’t do it!’ a few yoga devotees warned,” me among them as my initial reaction to his Phase I proposal to see what would happen when he keeps himself from nose breathing for ten days. But as a yogi who sees life as basically a long—if we’re lucky—and often dangerous and sometimes disastrous experiment, I inhaled his experiential and wide-ranging research into one of our bodies’ most basic functions. Nestor’s voice in the book is smart, compelling, funny, trustworthy—I wanted him to keep talking, to keep telling me his galloping story, but he paces the length exactly right. I came away from the immersive read with a broader understanding of the evolutionary and social history of our relationship with our breath, as well as an even deeper gratitude for all that yoga, meditation, and prayer have given me.