Modern WisdomHow To Breathe Properly | Brian Mackenzie | Modern Wisdom Podcast 121
CHAPTERS
- 0:00 – 2:28
Aerobic vs. anaerobic: why breathing determines your “default” energy system
Brian frames aerobic metabolism as the body’s most efficient energy pathway and explains anaerobic effort as what happens when you can’t meet demands aerobically. The core performance question becomes how quickly you can return to aerobic dominance after stress or intensity.
- •Aerobic metabolism as the primary, efficient energy conversion mode
- •Anaerobic work as a byproduct of failing to meet demands aerobically (not just a training choice)
- •Performance hinges on returning to aerobic function quickly
- •Example of elite endurance performance (sub-2 marathon) as an aerobic capacity demonstration
- 2:28 – 5:17
Why breathwork is overlooked—and how Brian came to it via yoga and endurance
Chris asks why breathwork rarely comes up even with elite coaches and clinicians. Brian recounts his early yoga exposure where breath cues didn’t “stick,” then his return to endurance coaching before a later breakthrough made breath mechanics feel immediately relevant to performance.
- •Breathwork often isn’t taught in performance-relevant language
- •Yoga included breath control, but it didn’t register for Brian initially
- •Endurance coaching background shaped his performance lens
- •Shift from flexibility/mobility focus to physiology and performance
- 5:17 – 8:22
The training mask “aha”: diaphragm, spine organization, and stress physiology
A training mask experiment triggers a strong sensation of rib expansion, diaphragm engagement, and posture change. Brian uses this to connect breathing mechanics to spinal organization, nervous system activation, and stress responses driven by CO2.
- •Mask didn’t simulate altitude but changed breathing mechanics
- •Diaphragm engagement affects rib cage expansion and spinal organization
- •Chemoreceptor-driven panic can occur without the amygdala
- •Poor breathing patterns can push sympathetic dominance and inefficiency
- 8:22 – 9:48
Nose vs. mouth breathing: your built-in training mask and metabolic differences
Brian argues the nose is a biological filter and regulator that influences breathing rate, immune function, and diaphragm recruitment. He shares early metabolic-cart experiments showing that even an easy dog walk produces different metabolic profiles depending on mouth vs. nose breathing.
- •Nasal breathing filters, humidifies, and conditions air; supports immune function
- •Nasal resistance can promote better diaphragm mechanics
- •Mouth vs. nose breathing changes metabolic output even at low intensity
- •Question becomes when mouth breathing is truly necessary
- 9:48 – 12:49
Pranayama, gas exchange, and why CO2 drives oxygen efficiency
Brian reframes pranayama as energy/breath control and ties it to measurable cellular respiration via gas exchange. He emphasizes that CO2 tolerance governs oxygen utilization efficiency, acid–base balance, and many downstream physiological effects.
- •Pranayama as ‘energy control’ and ‘breath control’
- •Breath is the measurable interface for cellular respiration
- •CO2 relationship determines oxygen delivery/use efficiency
- •Breathing regulates chemistry including acid–base balance
- 12:49 – 14:33
Static vs. working CO2 tolerance: specialists, free divers, and endurance athletes
Brian contrasts static breath-hold ability with performance under workload, noting that specialists can fall apart when work changes the CO2 tolerance demands. He uses free divers/big-wave surfers vs. elite endurance runners to illustrate different respiratory responses and adaptation needs.
- •High static CO2 tolerance doesn’t guarantee performance under exercise stress
- •Workload changes the CO2 tolerance ‘story’ dramatically
- •Specialists may show high respiration rates once work is applied
- •Endurance elites may be strong aerobically yet weak in static breath control
- 14:33 – 19:51
Breath, the brain, and prediction: why respiration drives emotion and heart rate
Brian maps breathing onto neurobiology: neocortex stories, limbic emotion, and brainstem respiration on autopilot. He explains chemoreceptor/baroreceptor prediction loops and why heart rate is ‘late to the game,’ with conscious breathing as the main lever for control.
- •Respiration centers in the brainstem respond to emotion, thought, and workload
- •Chemoreceptors and baroreceptors drive predictive breathing responses
- •Heart rate follows respiratory and CO2-driven signaling
- •Conscious breathing is the practical control mechanism for arousal
- 19:51 – 24:08
Sympathetic vs. parasympathetic: exhale as ‘inhibiting sympathetic’ + HRV manipulation
Brian challenges simplistic ‘exhale = parasympathetic’ framing, calling it inhibition of sympathetic drive. He discusses how breathwork can quickly shift HRV and ‘readiness,’ and how modern high-achievers often live stuck in sympathetic overdrive.
- •Inhale biases sympathetic activation; exhale inhibits sympathetic drive
- •Breath can intentionally shift HRV and readiness metrics
- •Readiness as an optimal arc between parasympathetic and slight sympathetic
- •Most people skew too sympathetic; some collapse into dissociation
- 24:08 – 30:08
The CO2 tolerance test: a fast diagnostic for mechanics, physiology, and panic response
Brian outlines his starting point for assessing breathing: a max-exhale CO2 tolerance test with a specific breathing setup. He explains how the result reflects diaphragm control, aerobic efficiency, and cognitive reactivity, using special forces examples to show how low scores correlate with injury and poor recovery.
- •Protocol: settle breathing → 4-breath pattern → timed slow max exhale
- •Three lenses: mechanical diaphragm control, physiological CO2 response, cognitive reactivity
- •Under ~20 seconds indicates a volatile/reactive system needing cleanup
- •Low CO2 tolerance links to tight/painful tissue, recovery issues, and overtraining
- 30:08 – 37:09
Why one-size breath methods fail: individual fingerprints, protocols, and the State app
Chris asks what’s trainable vs. physiological, and Brian explains why different people respond differently to the same protocol. He critiques universal claims across popular methods (Wim Hof, Buteyko, etc.) and describes building customization via the State app and algorithmic ‘fingerprinting.’
- •Different protocols produce different responses across individuals
- •Many breath methods overclaim or generalize beyond their effects
- •Breathing isn’t ‘the answer’—it’s an indicator of underlying state
- •Customization and progressive programming led to app-based delivery
- 37:09 – 40:26
Practical baseline: nasal-only breathing blocks + daily protocols for calm and sleep
Brian gives actionable guidance: short morning and evening protocols and, when possible, a 3–4 week block of nasal-only breathing across training. He argues this rewires physiology and exposes ego-driven intensity that blocks adaptation, regardless of sport.
- •Start: 5 minutes morning + 5 minutes evening breathing protocols
- •If not peaking for competition, do 3–4 weeks nasal-only in all training
- •Works across strength, CrossFit, MMA, endurance—adaptation takes ~3 weeks
- •Nasal breathing forces aerobic efficiency and better control under stress
- 40:26 – 45:11
Nasal breathing, evolution, and Kipchoge: staying aerobic and reading physiology
Brian returns to evolutionary context: aerobic metabolism as the efficient energy deal, with nasal breathing as a tool to maintain it. He analyzes Eliud Kipchoge’s breathing as primarily nasal during the marathon and connects anatomy, animal physiology, and efficiency signals to performance.
- •Nasal breathing supports aerobic dominance and energy efficiency
- •Aerobic vs anaerobic framed as energy conversion under stress
- •Kipchoge observed with mouth mostly shut; ‘salt marks’ as evidence
- •Animals largely nasal-breathe; mouth breathing appears with overheating/stress
- 45:11 – 54:17
Culture, convenience, and ‘black mouth’: mouth breathing, overstimulation, and sleep issues
Brian argues modern comfort and overstimulation push chronic mouth breathing and sympathetic dominance. He cites historical observations (George Catlin) about indigenous nasal breathing habits, then links mouth breathing to fatigue from talking, sleep disruption, and sleep apnea patterns.
- •Historical claim: indigenous cultures emphasized closed-mouth breathing
- •Mouth breathing ramps arousal and increases CO2 blow-off
- •Talking for hours can be exhausting via respiratory chemistry shift
- •Mouth opening during sleep increases sympathetic activation; ties to apnea patterns
- 54:17 – 59:04
Beyond breath: vision as the second conscious lever + redefining ‘human performance’
Brian introduces vision (peripheral gaze, nature exposure) as the other conscious control for autonomic state, alongside breath. He broadens ‘performance’ from lifting/racing feats to making better decisions under pressure—citing medical and high-stakes contexts.
- •Two conscious autonomic levers: breath and vision
- •Peripheral vision and natural scenes can downshift arousal
- •Human performance = better decisions under stress, not just metrics PRs
- •Training should connect to survival, regulation, and real-world functioning
- 59:04 – 1:06:12
Training for awareness, not winning: hypoxic carries, ego, and CO2 as stress messenger
Brian shares a seminar example (breath-hold farmer carries) where athletes try to ‘win’ instead of noticing internal signals. He closes the loop: training is about learning sensations and improving decision-making under stress, with CO2 as the body’s core stress messenger.
- •Hypoxic farmer carries used to reveal stress responses and sensation awareness
- •Ego-driven competition blocks learning from the exercise
- •Training’s foundation: make better decisions under stress
- •CO2 described as the body’s metabolic stress messenger
