The Diary of a CEOThe Breathing Expert: Mouth Breathing Linked To ADHD, Diabetes & Child Sickness!
CHAPTERS
- 0:00 – 14:20
Breathing As The Missing Pillar Of Health
Nestor introduces the idea that dysfunctional breathing underlies many modern diseases and that most people are unaware of how badly they breathe. He recounts his own history with chronic respiratory issues and how a single breathwork class transformed his health and curiosity as a science journalist.
- •Most people assume breathing is automatic and inconsequential, but Nestor argues it’s a core pillar of health alongside diet, exercise and sleep.
- •His own bronchitis, pneumonia, dry mouth at night and exercise-induced wheezing were dismissed as ‘aging’ until a doctor friend flagged his breathing.
- •A skeptical visit to a ‘new age’ breathwork class led to extreme physiological responses (profuse sweating in a cold room) and complete resolution of his respiratory issues.
- •This experience launched a decade-long investigation into breathing science, free-diving, and the limits of human physiology.
- 14:20 – 26:50
From Free-Diving Feats To Questioning Human Limits
Covering a free-diving championship in Greece showed Nestor that humans can do seemingly impossible things with a single breath. These feats convinced him that mainstream views of our physiological limits—and of breathing itself—are far too conservative.
- •Free divers routinely descend ~120 meters and stay underwater for around five minutes on one breath, then recover quickly.
- •Watching bodies shrink to specks in clear water and return alive shattered Nestor’s assumptions about the limits of human lungs and oxygen use.
- •He frames free divers as ‘experts in lung capacity’, able to access every available cubic centimeter of their lungs.
- •These observations reinforced his conviction that we’ve been ‘sold short’ on what our bodies can do through breathing.
- 26:50 – 44:00
How Modern Life Broke Our Breathing
The discussion shifts to how environmental and lifestyle changes have warped our facial structure, posture and automatic breathing patterns. Nestor argues that diseases like diabetes, asthma, autoimmune disorders and anxiety are deeply intertwined with dysfunctional breathing, especially at night.
- •Modern sitting, working, sleeping positions, processed foods, and pollution collectively ‘conspire’ against healthy breathing.
- •Research links poor night breathing and sleep apnea to metabolic breakdown, including the onset of type 2 diabetes and autoimmune conditions.
- •Chronic over-breathing and slouched posture keep people in low-grade sympathetic activation, contributing to inflammation and immune dysfunction.
- •Indigenous and traditional populations with minimal processed foods rarely have crooked teeth, asthma, or heart disease; they breathe efficiently and have broad faces with large airways.
- 44:00 – 56:20
The Stanford Mouth vs Nose Breathing Experiment
Nestor describes his self-experiment at Stanford comparing 10 days of enforced mouth breathing to 10 days of nasal breathing. The rapid deterioration in sleep, cognition and inflammation during the mouth-breathing phase gave objective data to back up traditional warnings.
- •He and breathing researcher Anders Olsson plugged their noses for 10 days, then did 10 days of mostly nasal breathing, keeping diet, steps and activity constant.
- •Within days of mouth breathing, both went from zero snoring to full snoring and sleep apnea, with severe fatigue despite 9–10 hours in bed.
- •Data showed major declines in sleep quality and increases in markers of inflammation and dysfunction.
- •Nestor emphasizes many people unknowingly live like this for months (e.g., allergy season), accumulating similar damage.
- 56:20 – 1:02:50
How Widespread Is Dysfunctional Breathing?
Drawing on respiratory therapists and elite athletic trainers, Nestor estimates that the vast majority of people breathe poorly. He introduces the idea of a spectrum of dysfunction, from severe asthmatics to high-performing athletes who still have suboptimal patterns.
- •Experts he interviewed estimate 95–99% of their clients breathe dysfunctionally in some way.
- •There’s a continuum: from asthma and panic attacks to elite athletes who perform well but over-breathe or mouth-breathe under load.
- •Nestor stresses that no one is a ‘perfect breather’, similar to how almost no one eats perfectly all the time.
- •Despite this, he believes everyone can become a ‘good breather’ with simple, free interventions that retrain unconscious habits.
- 1:02:50 – 1:11:40
Industrial Food, Small Jaws, And Lost Ancestral Breathing
Nestor links industrialized food to drastic changes in human skulls: smaller jaws, crooked teeth, and narrower airways. He explains how reduced chewing and altered infant feeding practices have reshaped faces in just a few generations, making efficient breathing structurally harder.
- •Pre-industrial skulls show straight teeth, wide palates, and large nasal passages; crooked teeth were virtually nonexistent.
- •Within one generation of canned/bottled/soft foods, about 50% of a population can develop crooked teeth, which signal a mouth too small for the face and an undersized airway.
- •Our ancestors chewed for three to four hours daily on tough meat, roots and fibers; modern diets demand minimal chewing.
- •Extended breastfeeding (around two years) and then transition to adult-textured foods help pull the face forward and widen airways; bottle-feeding is easier and often involves less orofacial stress.
- •He emphasizes this is environmental, not ‘evolutionary progress’: evolution simply means change, and in this case, it’s maladaptive.
- 1:11:40 – 1:25:50
Practical Mechanics: Diaphragm, Posture, And Everyday Office Life
The discussion becomes hands-on as Nestor teaches how to feel proper diaphragmatic movement and shows how modern sitting compresses breathing. He suggests simple workplace adaptations like standing desks and walking breaks to restore natural breathing mechanics.
- •The diaphragm is an umbrella-shaped muscle under the lungs; its descent creates a vacuum to draw air in, and ascent pushes air out.
- •Slumped sitting prevents proper diaphragm descent, forcing shallow chest breathing and reducing gas exchange efficiency.
- •He demonstrates self-checks: hands above hip bones to feel lateral expansion, fingers across the upper chest to feel subtle outward movement, and hands at the neck to ensure no tension or shrugging.
- •Proper breathing should be soft, almost invisible, with expansion starting low and then moving gently upward through the ribcage.
- •Standing desks, phone calls taken while standing or walking, and posture awareness are low-friction ways to improve breathing during long workdays.
- 1:25:50 – 1:39:30
Nasal Breathing, Nitric Oxide, And Immune Defense
Nestor explains why the mouth is a backup breathing system and the nose is primary. He details the nose’s many functions—from moisture recapture to nitric oxide production—and introduces simple humming as a cheap immune-support tool.
- •In nature, animals like cheetahs and horses run at full speed breathing only through their noses; mouth breathing appears primarily when they’re sick.
- •The nose filters particulates, warms and humidifies air, and recaptures roughly 40% more moisture than mouth breathing, reducing the need for constant drinking.
- •Nasal breathing increases nitric oxide production up to sixfold compared to mouth breathing; this gas supports vasodilation, circulation, and has antiviral and antibacterial properties.
- •Humming through the nose can increase nitric oxide levels up to 15-fold and has been shown in at least one study to resolve chronic rhinitis when done frequently.
- •Nestor argues that consistent nasal breathing likely lowers susceptibility to some infections, though large-scale trials on colds/flu are unlikely to be funded.
- 1:39:30 – 2:06:00
Children, Sleep-Disordered Breathing, And ADHD
The conversation delves into the alarming prevalence of mouth breathing and poor sleep in children, and its strong association with behavioral diagnoses like ADHD. Nestor relays research suggesting many such cases are fundamentally breathing and sleep problems, not primary brain disorders.
- •Many children have retrognathic (set-back) jaws and narrow airways from early in life, predisposing them to snoring and obstructed sleep.
- •A longitudinal study of 11,000+ children found those with sleep-disordered breathing had 50–90% higher risk of hyperactivity, aggression, depression and anxiety.
- •Some researchers he interviewed claim ADHD is ‘100% related to your breathing, at night especially’, though Nestor personally considers that somewhat overstated.
- •Surgical removal of tonsils/adenoids may help but often fails long-term if underlying breathing habits and airway structure are not addressed.
- •He urges parents to observe kids sleeping: audible breathing, open-mouth posture, or even subtle resistance sounds are red flags that should be evaluated urgently.
- 2:06:00 – 2:22:10
Breathing, Lung Capacity, And Longevity
Nestor presents evidence that lung size and function are among the strongest predictors of lifespan. He explains how lung capacity declines with age but can be preserved or expanded through exercise and targeted breathing practices.
- •The Framingham study and others found that larger, healthier lungs strongly predict longer life—better than many standard medical markers.
- •Transplant patients given larger donor lungs live significantly longer than those with smaller or normal-size lungs, regardless of original size.
- •Lung function typically starts declining after age 30, with acceleration around 50–60, especially in women.
- •Regular cardiovascular exercise, yoga, chest-opening stretches, and conscious deep breathing can maintain or increase lung capacity by 15–20%.
- •Nestor advocates using simple breath holds as a daily check-in of respiratory health and nervous system state.
- 2:22:10 – 2:31:00
Stress, Anxiety, And Using Breath To Hack The Nervous System
Nestor connects everyday stress responses—like holding the breath over emails—to ancient threat responses, and shows how deliberate breathing can quickly shift us between sympathetic ‘fight or flight’ and parasympathetic ‘rest and digest’.
- •Modern ‘email apnea’ mirrors ancient responses to predators: hold the breath to stay silent, then over-breathe to mobilize for action.
- •Chronically living in sympathetic activation due to work stress and notifications drives high blood pressure, metabolic issues and autoimmune problems.
- •He demonstrates the ‘physiological sigh’ (two inhales + long exhale) as an in-the-moment reset that’s subtle enough to do in public.
- •Slow, low, nasal breathing with slightly longer exhalations (e.g., 4 in, 6 out) measurably reduces heart rate and increases HRV.
- •He explains the physiology: inhalation slightly speeds the heart, exhalation slows it; emphasizing exhale amplifies the ‘safety’ signal to the nervous system.
- 2:31:00 – 2:48:40
Transformational Breathwork: Holotropic Practices And Emotional Release
The host and Nestor discuss intense breathwork sessions (holotropic, Kundalini, pranayama) that can feel psychedelic and emotionally cathartic. Nestor differentiates their deliberate stress mechanism from foundational breathing habits and calls for more research on their brain effects.
- •Vigorous breathing protocols often use fast mouth or nose breathing to deliberately induce a strong stress response and CO₂ drop, then integrate holds and slow breathing.
- •Physiological effects include reduced blood flow to the brain (up to ~40%), finger and hand cramping (‘tetany’) from calcium/CO₂ shifts, and altered consciousness.
- •Nestor likens them to ice baths or intense exercise: brief, deliberate stress bursts that recalibrate what feels threatening and discharge accumulated tension.
- •Participants frequently report ego softening, perspective shifts, and emotional breakthroughs—such as feeling compelled to reconcile conflicts.
- •He cautions that people should first establish solid basics (nasal, slow, diaphragmatic breathing) before experimenting with such powerful techniques.
- 2:48:40 – 3:14:00
CO₂, Indoor Air, Masks, And Hidden Cognitive Costs
The conversation turns to indoor air quality, COVID-era masking, and CO₂ as an overlooked indoor pollutant. Nestor demonstrates with a CO₂ meter how quickly levels rise in sealed rooms and cites compelling evidence that modest elevations impair cognition and health.
- •Outdoor CO₂ is around 418 ppm; indoors, 800 ppm is already associated with ~20% declines in test performance.
- •At 1,000–1,500 ppm, people report eye irritation, sore throats and other symptoms; studies show cognitive scores and decision-making degrade significantly.
- •Typical schools, offices, planes, and hotels often reach 1,500–2,700 ppm, meaning a large fraction of each breath is recycled exhaled air.
- •Nestor distinguishes between high-quality, correctly worn masks (which can reduce viral spread) versus the false security of poor masks combined with high-CO₂, poorly ventilated environments.
- •He predicts a coming push for buildings that provide genuine fresh air (e.g., openable windows, outside air intake) as people recognize the performance penalty of bad air.
- 3:14:00 – 3:32:10
Diagnostic And Training Tool: The BOLT / Control Pause
Nestor teaches a specific breath-hold test (BOLT/control pause) that acts both as a diagnostic of respiratory and nervous system health and as a way to train CO₂ tolerance over time.
- •Procedure: take a normal inhale, exhale to a neutral ‘just empty’ point, then start timing as you hold; stop at the first definite discomfort (swallow, diaphragm flick, mental urge to breathe) and resume normal breathing.
- •Target functional score is ~40 seconds with a relaxed, unforced first inhale after the hold; most people start near 15 seconds.
- •Elite athletes commonly record ~20 seconds when they first test; people with severe asthma or panic often manage only 3–5 seconds.
- •He stresses it’s not a maximal willpower test but a sensitivity gauge, and that scores vary by time of day, sleep quality, and meals—so weekly averages matter more than single readings.
- •Progressively improving this score through slower nasal breathing and gentle holds typically corresponds to reduced anxiety and better breathing efficiency.
- 3:32:10 – 4:08:20
Asthma, Medication, And Reversing ‘Diseases Of Civilization’
Nestor challenges the assumption that asthma is an inborn, lifelong condition and shares how breathing retraining has dramatically improved or resolved asthma in many cases. He critiques purely pharmaceutical approaches that ignore underlying breathing behavior.
- •He rejects the purely genetic, lifelong framing of asthma for most patients, likening it to type 2 diabetes, which can be reversed with dietary change.
- •He describes a 3‑year‑old with asthma facing tonsil/adenoid removal and lifelong steroids/bronchodilators whose nocturnal breathing is open-mouthed and noisy—an obvious but ignored factor.
- •Clinical trials for methods like Buteyko breathing show reduced symptoms and medication needs in asthmatics when they retrain their breathing.
- •He argues the root causes—airway structure and dysfunctional breathing patterns—must be addressed rather than just removing tissue or escalating drugs.
- •While not claiming universal cures, he insists that nearly every asthmatic can significantly reduce severity through proper breathing practice.
- 4:08:20
Closing Reflections: Simplicity, Responsibility, And Accessible Tools
Nestor ends by reiterating that the most powerful breathing interventions are simple, free and available to everyone. He hints at his upcoming BBC Maestro course as a structured toolbox and emphasizes curiosity as his driving motivation.
- •Key habits—nasal breathing, slower rates, better posture, sleep-focused interventions—require no equipment or expensive courses.
- •He wants people to master these foundational tools before chasing exotic methods or gadgets.
- •Breathing dysfunction, especially in kids, is serious and urgent, not a fringe wellness topic.
- •His BBC Maestro series aims to systematize practical techniques, along with additional science and historical material that didn’t fit in the book.
- •Asked what drives him to be his best, he answers simply: curiosity, and the privilege of having a job that lets him keep asking questions.
