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The Power of Breath to Energize, Calm, Shift Your Mood and More. With James Nestor

April 7, 2026·43 min·3 clips

Breathing only through his mouth for 10 days gave James Nestor instant sleep apnea and skyrocketed his stress.

1. Untangle hosts an encore episode in which Arielle interviews James Nestor, journalist and author of Breath: The New Science of a Lost Art, about the overlooked science of how humans breathe. 2. Nestor is a San Francisco-based science journalist who initially suffered from chronic bronchitis and minor pneumonia; Arielle serves as co-host and conducted the original interview. 3. The episode argues that the pathway through which air enters the body — nose versus mouth — has measurable, significant effects on sleep, blood pressure, stress, and lifespan. 4. Nestor's interest began in a San Francisco breathing class where he sweated without exercising, an effect his doctor could not explain, which led him to investigate freedivers who hold their breath for 5-8 minutes. 5. Working with Dr. Jayakar Nayak at Stanford, Nestor and a Swedish breathing therapist blocked their nostrils with silicone for 10 days, forcing exclusive mouth breathing. 6. During those 10 days, Nestor went from not snoring at all to immediately snoring and developing sleep apnea, with blood pressure rising approximately 20 points. 7. He reports that 25-50% of the population habitually breathes through their mouth, and Stanford is running a 200-person study on mouth breathing, nasal breathing, and sleep apnea. 8. Nestor describes a simple hack — a small piece of micropore surgical tape placed at the center of the lips at night — which he says trains the jaw closed without hermetically sealing the mouth. 9. Italian researchers found that breathing at 5.5 seconds in and 5.5 seconds out — approximately 5.5 breaths per minute — brings the body into physiological 'coherence,' where heart and nervous system function in smooth sine waves. 10. This 5.5-breath rhythm matches the recitation rate of the Catholic Ave Maria rosary and the Buddhist Om Mani Padme Hum, a cross-cultural convergence Nestor treats as evidence of ancient empirical knowledge. 11. Nestor explains that exhaling more than inhaling activates parasympathetic relaxation, while inhaling more activates sympathetic stimulation, forming the basis of most named breathing systems across cultures. 12. A 1980s Framingham-linked study tracking roughly 5,000 patients over three decades found that lung volume and respiratory health predicted lifespan more strongly than genetics, diet, or exercise. 13. A separate study Nestor cites found that lung transplant recipients given larger lungs lived longer lives than those given smaller ones. 14. Lung capacity begins shrinking around age 30 at approximately 15% per decade, but Nestor says free divers demonstrate it can be expanded — some have 12-liter lung capacity versus an average adult male's 6 liters. 15. Holotropic breathwork, developed by LSD researcher Stan Groff after LSD was banned in 1968, involves three hours of hard breathing to deliberately induce CO2 depletion and extreme stress as a therapeutic purge. 16. Wim Hof's method — 30 rapid breaths followed by a held exhale and a 15-second inhale hold — was adapted from ancient pranayama techniques and is used to compress chronic low-grade stress into a short session. 17. Breathing too many breaths per minute (over 18) during exercise puts most air into 'dead space' — the throat, bronchi, and upper nose — reducing actual oxygen delivery to the lungs. 18. The episode is conversational and educational, with Arielle asking Nestor to explain mechanisms and occasionally testing techniques live on air. 19. People who snore, have sleep apnea, high blood pressure, or want practical tools for managing stress and energy would find this episode directly applicable. 20. Listeners who prefer abstract wellness philosophy or are skeptical of biohacking-adjacent content may find the episode's emphasis on physiology and specific metrics less engaging.

As heard by us

Breathwork is treated as practice and puzzle, with just enough skepticism to keep it grounded.

Breathwork is treated here as something sturdier than a wellness fad, and the strongest stretch is the one on holotropic breathwork. The piece walks through where it came from, what happens in a session, and why the explanation seems to lean more toward carbon dioxide than a…

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Why you'd press play

When you want holotropic breathwork explained without the usual woo.

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