The Gravity Doctors

In this reflective "backyard" session in Los Angeles, Brennan and his co-host discuss the current state of BiogravitationalMedicine (BGM) and the Mental Gravity theory. They explore the challenges of introducing a physics-based framework into the traditional silos of medicine and psychology, the excitement of early adopters, and how a simple shift in perspective—viewing the body as a "physics-fighting engine"—can empower individuals to take control of their health.

Key Takeaways:

Physics First, Biology Second: The core of BGM is the understanding that our minds and bodies are a directconsequence of evolving under Earth's gravity.

The Hub of the Wheel: Gravity is presented not as a new "spoke" of medicine, but as the hub that connects all physiological systems and illnesses.

Mental Gravity as a Practice: The "Mental Gravity" app translates these theories into pragmatic, intuitive steps for mental fitness, moving away from abstract psychologicalterms toward grounded physical principles.

Breaking the Silos: Despite pushback from specialists who prefer to stay in their "lanes," BGM seeks to bridge the gap between physics, gastroenterology, neuroscience, and psychology.

The "Space Science" Connection: The ill effects astronauts experience from a lack of gravity serve as a powerful "AHA!" moment for skeptics to understand why gravity is essential for terrestrial health.

Timestamps:

00:00 – Reflective Mood in LA: Assessing the progress of Biogravitational Medicine one to two years in.

01:30 – Understanding the Framework: Why people resonate with the idea that life emerged to manage physics.

03:00 – Mental Gravity & Intuitive Health: Launching the Mental Gravity company and app to describe feelings in grounded, physical terms.

04:00 – Mainstream Endorsement: Discussing the deep-dive conversation with Mel Robbins and the pragmatic side of BGM.

06:00 – Closing the Knowledge-Action Gap: Empowering individuals to correct their perception of "mental weight" through action.

07:30 – Aristotle vs. Plato: Moving from the "Platonic realm" of abstract ideals back down to the grounded "Aristotelian" reality of the body.

09:30 – Language vs. Reality: Why "feeling down" is more than just a metaphor—it’s a physical consequence.

12:00 – "Off the Deep End": Dealing with skepticism and the stigma of mixing physics with clinical medicine.

15:30 – Universal Principles: Drawing parallels between BGM and models used in economics and chaos theory.

17:00 – The Free Energy Principle: How neuroscience is already beginning to use physics-based tools like active inference.

19:30 – The Space Medicine Niche: How the peer-review process is opening up through the lens of astronaut health.

21:00 – Interrelated Systems: Lessons from gastroenterology on how the brain, gut, and microbiome are all physically connected.

23:30 – The Goldilocks Zone: Achieving balance between sedentary living and overtraining within 1G of force.

25:30 – The "Let Them" Mindset Shift: Why BGM is a powerful psychological tool for health promotion.

26:45 – Wrapping Up: A look toward the next year of evolution for the theory.

Resources

The Gravity Doctors: ⁠https://thegravitydoctors.com⁠

Dr. Brennan Spiegel: ⁠https://brennanspiegelmd.com⁠

Dr. Lachlan Kent: ⁠https://lachlankent.au⁠

Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health

In this episode, we dive into the surprising science of "gravity intolerance" and why lying in bed might be one of the worst things you can do for your recovery. Whether you're dealing with a common flu, recovering from major surgery, or managing a long-term illness, the simple act of gettingvertical can be a "physics-fighting engine" for your body and mind. We explore NASA’s "Pillow-naut" studies, the link between inactivity and depression, and how hospitals are using "Art Tours" and gamification to get patients back on their feet.

Key Takeaways:

The Danger of Deconditioning: Staying flat for too long leads to "gravity intolerance," affecting everything from your cardiovascular system to your gut health (Ileus).

The NASA Lesson: Lessons from simulated space environments show that lying down causes fluid shifts that lead to headaches, vision issues, and a "shock to the system" when finally standing up.

The 1,000 Step Rule: Patients who can manage just 1,000 steps the day after surgery are significantly more likely to be discharged faster.

MentalGravity: Physical inactivity and depression aren't just cause-and-effect; they are a feedback loop. Standing up is a literal and metaphorical way to fight mental "pull".

Timestamps:

00:00 – The "Hit by a Bus" Feeling: Personal memories of COVID and the exhaustion of illness.

01:22 – The Hospital Dilemma: Why we put our sickest patients in bed and the risks of being "risk-averse".

02:15 – What Happens to Your Body When You Stay Flat: Gut slowing (Ileus), skin breakdown, and cardiovascular deconditioning.

03:00 – Lessons from NASA: The "Pillow-naut" studies and what happens when gravity stops pulling blood to your ankles.

04:30 – The Shock of Getting Vertical: Why the first walk after a long illness feels like the Earth is a magnet.

05:30 – Fighting for Your Life: The story of Harman Clark and the mindset shift required for recovery.

07:30 – Gamifying Recovery: Using Fitbits and "Art Tours" at Cedars-Sinai to encourage patient movement.

09:40 – Moving Beyond "Standing Orders": The importance of walking vs. just sitting in a chair.

11:15 – Being an Active Participant: Why you shouldn't wait for recovery to happen—you have to give it a nudge.

12:30 – The Connection to Mental Health: How inactivity heightens the risk of depression and helplessness.

14:30 – "Mental Gravity": A new way to look at the feedback loop between the mind and body.

16:00 – Final Thoughts: Next time you feel down, think about standing up.

Resources

The Gravity Doctors: ⁠https://thegravitydoctors.com⁠

Dr. Brennan Spiegel: ⁠https://brennanspiegelmd.com⁠

Dr. Lachlan Kent: ⁠https://lachlankent.au⁠

Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health

In this episode, Dr. Brennan Spiegel (physician, gastroenterologist, and author of Pull) and Dr. Lachlan Kent(cognitive scientist and founder of Mental Gravity) explore the physical, psychological, and existential implications of humanity's return to the moon.

They examine how the Artemis mission acts as a "Global Unifier," shifting the narrative from territorial conflict to a collective human achievement.

Broadcasting as a "crew of two," they reflect on the transition from the stoic, emotionally restrained era of Apollo to the joyful, diverse, and deeply "human" experience of modern space exploration. They connect the physics of "untethering"from Earth to the metaphysics of "mental gravity," arguing that space travel is the ultimate expression of humanity's anti-gravity mission.

One Giant Leap for Humanity: The ArtemisPerspective

• A Global Unifier: A 21st-century mission that transcends national borders, bringing the world together to witness one of humanity's greatest achievements.
• The Physics of Fragility: An exploration of the "immense forces" required to fight gravity and the vulnerability of the human body in zero-G environments.
• The Overview Effect: The profound psychological realization that occurs when astronauts look back at the planet and see it not as a collection of countries, but as a single "crew" on Spaceship Earth.
• Humanizing Space: A shift from the "stoic" pilots of the 1960s to a mission characterized by visible joy, big hugs, and diverseleadership.

Space Travel as a Biogravitational Mission

• Breaking the Tether: Humanity’s evolutionary history is defined by standing up and using intelligence to build machines that allow us to fly and eventually "blast off" from the planet.
• The Two Portals: Space travel forces a confrontation with two realities: the "awe-inspiring" view of home and the "existential dread" of the black void.
• Inner Space vs. Outer Space: The lessons learned from reaching the moon are applied to "inner space," helping individuals navigate the gravitational pull of their own minds.

Timecodes

• 00:04 — Introduction to the Artemis mission and its global significance.
• 00:30 — Exploring the social and spiritual implications of overcoming gravity.
• 01:38 — Artemis as a "Global Unifier"transcending national borders.
• 02:14 — The physics of untethering and the fragility of the human body.
• 02:43 — Reflections on looking back at "SpaceshipEarth".
• 04:24 — Humanizing space: Comparing modern joy and diversity to Apollo-era stoicism.
• 05:56 — The nuance of falling and fighting gravity as alife force.
• 07:34 — Standing up as humanity's existential mission.
• 08:41 — The anti-gravity mission: Breaking the tether to bring consciousness beyond Earth.
• 10:11 — Space travel as a driver for new scientific and experiential understanding.
• 12:37 — Pioneering, science, and the phenomenology of the unknown.
• 14:56 — Mental Gravity: Elevation and perspective vs.the "stuckness" of depression.
• 16:11 — The Astronaut's Perspective: De-centering tofind meaning and universal connection.
• 18:43 — The Two Portals: Navigating the "OverviewEffect" (awe) and the black void (dread).
• 22:16 — The spiritual dimension of gravity and the physical induction of awe.
• 22:39 — Oceanic consciousness, ego dissolution, and the transient self.
• 25:26 — Choosing a portal: Naturalistic spirituality and the news of a "cosmic whole".
• 27:00 — The evolution of the "crew":Interconnection as a strategy for mutual survival.
• 28:42 — Selflessness vs. Selfishness: Finding hopeful signs of social cohesion.
• 32:00 — Convergence: Biogravitational medicine as a holistic approach to humanity's future.
• 34:56 — Closing: Inviting others into the"crew" and future launch of Mental Gravity.

Resources

• The Gravity Doctors: https://thegravitydoctors.com
• Dr. Brennan Spiegel: https://brennanspiegelmd.com
• Dr. Lachlan Kent: https://lachlankent.au
• Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health

Dr Lachlan Kent is joined by Dr Mats Niklasson, developmental psychologist, visiting Research Fellow at the University of Greater Manchester, and co-founder of Sensorimotor Therapy, to explore how early vestibular development shapes both physical coordination and the narrative sense of self.

Drawing on nearly 40 years of clinical work with children and adults experiencing coordination and concentration difficulties, Mats explains how early reflexes—especially the Moro (startle/falling) reflex—connect infants to gravity. When these developmental processes are disrupted, the result may be delayed motor patterns, emotional dysregulation, learning challenges, and even later-life identity instability.

Using the life of Kurt Cobain as a psychobiographical case study, the conversation explores how gravitational insecurity may influence creativity, mental health, and the lifelong struggle to feel “at home” in one’s own body.

Check out Mat's book on the topic: "The discovery of international autoethnographical psychobiography"

https://bookstore.emerald.com/the-discovery-of-international-digital-collaborative-autoethnographical-psychobiography-hb-9781837083817.html

1. Sensorimotor Therapy & Gravity

A developmental approach grounded in movement and balance

Focuses on vestibular activation and early motor patterns

Links physiology and psychology through embodied development

Works by re-engaging early fetal-style movements

The goal:Reconnect the nervous system with gravity to release arrested development

Primary Reflexes & Early Development

All infants are born with survival reflexes

The Moro reflex is closely tied to the vestibular system

If not properly integrated:

• Crawling patterns may be skipped
• Walking and speech may be delayed
• Concentration and coordination may suffer

Vestibular development sits on a continuum—not simply “normal” vs “impaired”

Reconnecting to Gravity

Therapy works by:

• Recreating early fetal movement patterns
• Engaging attachment between child and caregiver
• Stimulating vestibular systems

Observed outcomes include:

Return of expected motor patternsImproved regulationReduction in headaches and stomach achesThis suggests a deep link between vestibular development and whole-body wellbeing

From Body to Biography

Mats connects early vestibular insecurity to later psychological outcomes:

Development is trajectory-based

Small early deviations may compound over time

Identity itself may emerge from embodied stability.

Kurt Cobain as Case Study

Niklasson’s analysis suggests:

Possible early developmental difficulties

Verified diagnoses included scoliosis and chronic bronchitis

Chronic stomach pain remained unexplained

He may have suffered from IBS—undiagnosed in his lifetime

Vestibular instability may have influenced:

• Sensitivity
• Withdrawal
• Creativity
• Search for equilibrium

Niklasson proposes Cobain may have been “a victim of his time,” lacking modern frameworks to understand syndrome-like conditions

Creativity & Instability

Drawing on Coleridge’s distinction between:

Fancy imagination (common)

Secondary imagination (rare, generative)

Some creative individuals may channel instability into talent.

Therapeutic balance is key:

Stability may reduce suffering

But may also alter creative expression

Resources

The Gravity Doctors: https://thegravitydoctors.com

Dr Brennan Spiegel: https://brennanspiegelmd.com

Dr Lachlan Kent: https://lachlankent.au

Dr Brennan Spiegel (physician, gastroenterologist, and author of Pull) and Dr Lachlan Kent (cognitive scientist and founder of Mental Gravity) explore how seasons, sunlight, serotonin, and gravity shape mood, attraction, and human connection.

Broadcasting from opposite hemispheres—Brennan in winter in Los Angeles and Lachlan in summer in Melbourne—they examine why people often feel more “down” in winter, why this is linked to reduced sunlight and serotonin, and how this helps explain the phenomenon known as “cuffing season”—the seasonal urge to pair up.

They connect dating, love, posture, breath, yoga, serotonin, oxytocin, and even planetary orbits into a single biogravitational story: human connection is shaped by the same gravitational cycles that shape the seasons themselves.

Seasons as Gravitational Cycles

Seasons arise from Earth’s orbit around the sun
Not just temperature cycles, but gravitational and light cycles

Mood follows seasonal gravity:

Summer = outward, expansive, light

Winter = inward, heavy, contracting
Breath mirrors this cycle: in/up, out/down

Winter, Serotonin, and Mental Gravity

Sunlight boosts serotonin
Low winter sunlight → lower serotonin → heavier mood
Seasonal Affective Disorder (SAD) as a gravity-related mood state
Serotonin as a “gravity management molecule” that supports:

• Muscle tone
• Circulation
• Upright posture
• Mental elevation

Love, Attraction, and Gravity

“Falling in love” uses gravitational language
Uprightness—physical, emotional, moral—is attractive
Winter dating favors depth over display
Spring favors peacocking; winter favors bonding
Long-term connection as gravitational alignment of values

Winter Practices for Gravity Resilience

Movement & Posture
Yoga as a winter-friendly anti-gravity practice
Inversions, posture, alignment, balance
Low-intensity movement over intense training

Light &Environment
Maximize sunlight exposure
Use light boxes in high-latitude winters
Get outside when possible

Diet & Chemistry
Tryptophan-rich foods: turkey, avocado, chicken, chickpeas, kidney, beans, eggs, tofu, nuts
Support serotonin production through diet

Connection
Cuddling, closeness, bonding
Oxytocin release
Oxytocin → vagus nerve → serotonin
Parasympathetic “rest and digest” state

Neurochemistry of Winter Bonding

Oxytocin primes vagus nerve
Vagus nerve regulates serotonin release
Cuddling + calm = anti-gravity physiology
Parasympathetic tone matches seasonal slowing

Biogravitational Medicine in Daily Life

Human health reflects planetary physics
Sun, moon, Earth, and orbit shape biology
Mood, love, and seasons are not mystical—just natural
Gravity as the hidden organizer of emotion, posture, and connection

Timecodes

00:00 — Welcome & hemispheres
01:15 — Seasons and gravity
02:15 — What is cuffing season?
03:15 — Mood, winter, and seasonal affect
04:40 — Sunlight, serotonin, and heaviness
06:05 — Planetary cycles and breath cycles
07:15 — Love as anti-gravity
08:15 — Depth vs display in dating
09:20 — Uprightness and attraction
10:45 — Winter activities and posture
11:35 — Yoga and winter gravity
13:15 — Balance, breath, and alignment
15:40 — Light therapy and sunlight
16:40 — Diet and serotonin foods
16:55 — Cuddling, oxytocin, vagus nerve
18:15 — Parasympathetic winter mode
19:05 — Biogravitation and planetary life
20:35 — Falling in love & falling physically
21:00 — Closing reflections

Resources

The Gravity Doctors: https://thegravitydoctors.com
Dr Brennan Spiegel: https://brennanspiegelmd.com
Dr Lachlan Kent: https://lachlankent.au
Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health

Dr Lachlan Kent and Dr Brennan Spiegel are joined by Elisa R. Ferrè, professor of cognitive neuroscience at Birkbeck, University of London, and one of the world’s leading experts on graviception and the vestibular system.

Together, they explore how the brain senses gravity without a single “gravity receptor,” why the vestibular system has no primary cortex, and how gravity is computed as a distributed, multisensory model integrating vestibular, visual, proprioceptive, and visceral signals. The conversation spans neuroscience, emotion, aesthetics, culture, spaceflight, and mental health—revealing gravity as the hidden scaffolding of perception, meaning, and wellbeing.

1. What Is Graviception?

The brain’s ability to sense and model gravityNot driven by a single receptor or cortical areaConstructed through multisensory integrationFundamental to embodiment, orientation, and survival

Why the Vestibular System Is Unique

No unimodal “vestibular cortex”
Projects broadly across the brain
Does not produce a clear conscious sensation
Becomes noticeable mainly when something goes wrong (dizziness, vertigo, nausea)

The vestibular system acts as the glue binding mind and body, anchoring us in a single embodied perspective.

How the Brain Computes Gravity

Gravity is not perceived directlyThe brain integrates:

• Vestibular otolith signals (head tilt, linearacceleration)
• Visual cues (verticality, alignment)
• Proprioception (joints, muscles, posture)
• Visceral signals (internal organs)

Each signal is weighted by reliability to form an internal model of terrestrial gravity.

Gravity, Meaning, and Culture

Preferences for verticality (upright lines, tall buildings)
Vertical = power, stability, positivity
Downward tilt = unease, disorder
Gravity shapes art, architecture, language, and metaphor

Up = good, free, elevated
Down = heavy, negative, constrained

Emotion, Fear, and the Vestibular System

Vestibular pathways connect directly to:

• Amygdala
• Insula
• Hypothalamus

This explains why vestibular disturbances are emotionally chargedDizziness and vertigo trigger fear, nausea, and autonomic responses
Gravity sensing is deeply tied to survival systems

Weightlessness and Freedom

Parabolic flight (“vomit comet”) as a unique graviceptive state
Weightlessness described as profound freedom
Also physiologically challenging
Post-flight “down” feelings mirror return to gravity

Freedom comes with a cost: sensory conflict and adaptation demands.

Space Adaptation & Neuroplasticity

Astronauts experience space motion sickness
Symptoms: nausea, disorientation, brain fog
The brain can adapt through neuroplasticity
Adaptation takes time, energy, and training

Implicationsfor long-term space travel and Mars exploration.

Gravity, Mental Health, and Everyday Life

Anxiety as mis-tuned gravity anticipation
Depression as altered temporal and bodily grounding
Mental fitness as trainable gravity resilience

Tools discussed:

• Yoga and posture
• Breath awareness
• Grounding through the feet
• Weighted blankets
• Music, rest, and multisensory regulation

Practical Graviceptive Tip

Stand still and feel the pressure through the soles of your feet
Notice the security of 1G
Use grounding as a way to reduce anxiety and reset expectations

Timecodes

00:00 — Introduction & guest welcome
02:00 — What makes the vestibular system unique
05:00 — Why gravity is mostly unconscious
06:30 — How the brain computes gravity
09:30 — Homunculus vs gravity computation
11:30 — Gravity as a prior for perception
14:00 — Semantics, aesthetics & verticality
17:00 — Architecture, art & meaning
20:00 — Vestibular system & emotion
22:00 — Parabolic flight & weightlessness
24:00 — Freedom, addiction & the cost of zero-G
28:30 — Space adaptation syndrome
31:00 — Can humans adapt to Mars?
35:30 — Everyday graviception & grounding
38:00 — Closing reflections

Resources

The Gravity Doctors: https://thegravitydoctors.com
Dr Brennan Spiegel: https://brennanspiegelmd.com
Dr Lachlan Kent: https://lachlankent.au

Dr Brennan Spiegel (physician, gastroenterologist, and author of Pull) and Dr Lachlan Kent (cognitive scientist and founder of Mental Gravity) drop an emergency episode to unpack one of the most extreme acts of gravity defiance ever witnessed: Alex Honnold climbing a 100-plus-storey skyscraper without ropes.

Using Honnold as an “extreme phenotype,” they explore what his remarkable calm reveals about fear, anxiety, graviception, and mental gravity. Drawing on neuroscience, psychology, and lived experience, they examine how Honnold’s quiet amygdala, finely tuned salience network, and relentless present-momentfocus allow him to operate where most humans would be paralysed by fear.

The episode bridges elite performance and everyday mental health, asking: what can the rest of us learn—safely—from someone who literally does not fear falling?

1. Why Alex Honnold Matters

A real-world example of ultimate gravity resilienceFree-solo climbing as the most literal test of mental gravityAnxiety, fear of falling, and bodily panic stripped awayA window into the far edge of human psychological capacity

Fear, Falling, and the Brain

Amygdala
Honnold’s amygdala shows minimal activation to fear-inducing stimuli
Contrast with anxiety, chronic pain, IBS, and fibromyalgia, where the amygdala is hyper-vigilant

Salience Network & Anterior Insula
Detects what matters in the body and environment
Simulates graviceptive cues without triggering panic
Anchors awareness in the present moment

Being in the Moment—Taken Seriously

Honnold’s survival depends on microsecond-level presence
No anticipatory anxiety, no future projection
Finger placement, balance, and movement solved in real time
Presence as an adaptive skill—not a slogan

Gravity Sensitivity as a Continuum

Humans vary widely in tolerance for heights, G-forces, and risk
Too much fear → paralysis
Too little fear → danger
Healthy functioning lies in the middle of the curve

Mental Gravity, Anxiety, and Depression

Anxiety = anticipation of falling
Depression = being stuck or weighed down in the present
Honnold represents the opposite extreme: calm within gravity
Insights help reframe everyday anxiety as mis-tuned gravity perception

Training vs Talent

Honnold combines rare inborn traits with years of intense training
Physical: extreme strength, precision, endurance
Mental: emotional regulation, present-moment focus
Fear is not absent—it is managed and contained

What Can We Learn (Safely)?

Not to climb skyscrapers—but to train mental fitness:

• Cognitive Behavioural Therapy as mentaltraining
• Meditation as present-moment conditioning
• Breathwork, yoga, and grounding practices
• Social connection and rest as recovery
• Balancing effort and recovery (noovertraining)

Mental fitness = something you work on, not something you either have or don’t have.

One Percent Rule

You don’t need to be Alex Honnold
Channeling 1% of his presence, calm, and training can meaningfully improve everyday resilience

Timecodes

00:00 — Emergency episode & skyscraper climb
01:10 — Free Solo and gravity defiance
02:15 — Watching the footage & bodily reactions
02:45 — Fear, falling & butterflies
03:30 — Amygdala findings
04:20 — Anxiety, pain & hyper-vigilance
05:10 — Salience network & graviception
06:20 — Courage vs fearlessness
06:50 — Gravity sensitivity across populations
07:50 — Mental gravity & anxiety
08:50 — Training, not recklessness
10:00 — Being truly in the moment
11:10 — Depression, anxiety & time orientation
12:05 — Learning from extreme phenotypes
13:20 — Mental health in a steeper world
14:20 — Training for modern life
15:20 — Mental fitness beyond CBT
16:10 — Meditation, breath & balance
17:35 — One percent of Honnold
18:30 — Closing reflections

Resources

The Gravity Doctors: https://thegravitydoctors.com
Dr Brennan Spiegel: https://brennanspiegelmd.com
Dr Lachlan Kent: https://lachlankent.au
Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health

How do elite athletes use body, mind, joy, and meaning to push beyond physical limits?

Dr Brennan Spiegel (physician, gastroenterologist, and author of Pull) and Dr Lachlan Kent (cognitive scientist and founder of Mental Gravity) explore theOlympics as humanity’s greatest laboratory for defying gravity.

With the Winter Olympics approaching, they examine elite athletes as “physics-fighting engines”—bodies and minds trained to resist, redirect, and sometimes seemingly escape gravity. Through stories of Cathy Freeman, Quincy Hall, Alex Honnold, and modern superstars like Steph Curry and Luka Dončić, they show how peak performance is not just physical—it is mental gravity management.

They introduce Olympic training as a real-world expression of biogravitational medicine, where strength, balance, imagery, joy, poise, team culture, and meaning all shape how far humans can push their relationship with gravity.

1. Why the Olympics Matter to Mental Gravity

The Olympics showcase humanity at the edge of physical limits

Elite sport = everyday gravity management taken to extremes
Athletes model what it means to fight gravity physically and mentally
Peak performance = synchronization of body, brain, and meaning

Athletes as Anti-Gravity Prototypes

Cathy Freeman (Sydney 2000)
“Floating” to gold in the 400m
Home crowd as acceleration, not pressure
Up, light, fast = opposite of depression

Quincy Hall (Paris 400m Final)
Turning failure into flight
Last-minute mental reversal → physical transcendence

Basketball, Ski Jumping, SkatingLeaping, flying, spinning, managing G-forcesAngular momentum and rotational control as gravity mastery

Mental Gravity in Elite Performance

Performance depends on mental poise, not just muscle
Stillness before action
Pressure as fuel, not burden
Crowds as acceleration, not oppression
Joy as a performance amplifier

Examples:
Steph Curry — joy + precision
Luka Dončić — playfulness under pressure
Ash Barty — recovery from “the yips” through joy

Imagery, Rehearsal, and Gravity

Mental imagery as bodily rehearsal
Kyrie Irving visualizing free throws
Alex Honnold mentally climbing El Capitan before climbing it

Mental gravity = using body as template for thought and emotion

Up = energized
Down = heavy
Calm = balanced

Fear, Falling, and Mastery

Fear of falling = gravitational anxiety
Elite athletes train to feel secure within gravity
Butterflies in the belly = falling sensations
Great athletes use fear to prime—not paralyze—the nervous system

Timecodes

00:00 — Welcome & why the Olympics matter
01:00 — Peak athleticism as defying gravity
02:00 — Cathy Freeman & floating to gold
03:30 — Winter sports & G-forces
04:30 — Quincy Hall’s last-minute flight
06:00 — Mental vs physical performance
07:30 — Stillness, pressure & acceleration
09:00 — Joy as a performance tool
10:30 — The yips, anxiety & recovery
12:00 — Mental imagery in sport
13:30 — Kyrie Irving & visualization
14:45 — Alex Honnold & fear mastery
16:15 — Fear, falling & butterflies
17:45 — Biogravitational training stacks
19:00 — Team culture & social gravity
20:30 — VR, the Proteus Effect & training
22:00 — Dead hangs & gravity endurance
24:00 — Olympics as humanity’s gravity experiment
25:00 — Closing reflections

Resources

The Gravity Doctors: https://thegravitydoctors.com
Dr Brennan Spiegel: https://brennanspiegelmd.com
Dr Lachlan Kent: https://lachlankent.au
Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health

Dr Brennan Spiegel (physician, gastroenterologist, and author of Pull) and Dr Lachlan Kent (cognitive scientist and founder of Mental Gravity) explore serotonin as a gravity-management molecule, reframing it not simply as a “happiness chemical,” but as a fundamental biological system that allows life to stand up, move fluids, regulate balance, and remain psychologically buoyant in a gravitational field.

Together, Brennan and Lachlan unpack new research on serotonin’s role across the gut, cardiovascular system, lymphatics, vestibular system, reproduction, and mood—showing how 95% of serotonin is produced in the gut, in symbiosis with the microbiome. They trace serotonin’s evolutionary origins from ocean life to land, altitude, and even space, and discuss practical implications for diet, exercise, sunlight, microbiome care, and mental health.

1. What Is Serotonin?

A whole-body gravity resilience molecule, not just a brainneurotransmitter

Exists in two largely separate compartments: brain and gut
Central to movement, circulation, balance, mood, and vitality
Evolutionarily conserved across plants, animals, and humans

Serotonin as a Gravity-Management System

Gut & DigestionMotility against gravity in any body orientation

Pumps & Tubes
Blood pressure regulation, cardiac contractility, lymphatic return

Balance& OrientationVestibular function; dizziness during SSRI withdrawal

Reproduction
Retrograde uterine contractions that move sperm upward against gravity

Mood &Energy
Mental elevation, vitality, resilience, and time perception

The Microbiome–Serotonin Alliance

Trillionsof microbes are required to trigger serotonin production
The gut as a “dark, sulfurous, hydrothermal” evolutionary niche
A symbiotic bargain: microbes get mobility; humans get serotonin
Changes in altitude, microgravity, and spaceflight rapidly alter serotoninbiology

STACK TEN: The Anti-Gravity Diet (introduced)

A practical framework from Pull for supporting serotonin production via tryptophan-rich foods.

Core principles:Tryptophan as substrateMicrobiome diversityDietary balance rather than supplementation alone

Therapeutic & Self-Care Implications

Dietary modification (tryptophan-rich foods, microbiome-supportive diets)Exercise and movementSunlight and time outdoorsWorking with dietitians for GI and mood conditions (e.g., low-FODMAP when indicated)Understanding limits and side effects of SSRIsNaturally supporting serotonin across body and mind

Metaphor & Meaning

The gutmicrobiome as the “spice factory” of human biologySerotonin as the true “spice of life”—powerful, regulating, and double-edgedGravity as the organizing principle linking biology, psychology, and medicine

Timecodes

00:00 —Welcome & why serotonin matters
01:10 — Serotonin beyond the “happiness chemical”
02:20 — Gut vs brain serotonin compartments
03:20 — Pumps, tubes & whole-body effects
04:25 — Lymphatics, reproduction & balance
06:20 — Evolutionary origins & gravitation
08:10 — Microbiome symbiosis metaphor
10:15 — Altitude, spaceflight & serotonin disruption
11:30 — STACK TEN diet introduced
12:45 — Diet, microbiome & mood disorders
13:50 — Dune, spice & serotonin metaphor
15:45 — SSRIs: benefits, limits & side effects
17:00 — Natural serotonin support & integration
17:45 — Closing reflections & next steps

Resources

The Gravity Doctors website: https://thegravitydoctors.com
Dr Brennan Spiegel: https://brennanspiegelmd.com
Dr Lachlan Kent: https://lachlankent.au
Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health

Dr Brennan Spiegel (physician, gastroenterologist, and author of Pull) and Dr Lachlan Kent (cognitive scientist and founder of Mental Gravity) explore how diet, microbiome diversity, and serotonin production shape your capacity to stand up to gravity—physically and mentally.

They introduce the Anti-Gravity Diet and Brennan’s STACK TEN framework, a simple, evidence-informed way to support the gut’s serotonin “factories” and improve whole-body gravity resilience. Along the way, they unpack how food, fibre, omega-3s, polyphenols, vagus-nerve activation, and mindful rest all participate in the body–mind system that keeps us upright and energised.

Together, Brennan and Lachlan discuss babies as “gravity novices,” leaky gut, the gut–brain axis, evolutionary embodiment, time dilation in depression, and why serotonin—serum tone—is essential for managing the constant downward pull of Earth’s gravity.

• A holistic framework for supporting natural serotonin production—the body’s anti-gravity molecule.
  Grounded in gastrointestinal physiology, microbiome science, and biogravitational medicine.
• Not a restrictive diet — a practical, everyday toolkit for gravity resilience.

A memory device for foods that supply the raw material (tryptophan) for serotonin production:

Salmon
Turkey
Avocado
Chickpeas
Kidney beans
Tofu/Tempeh
Eggs
Nuts

Paired with:

• Fibre → feeds microbes that create short-chain fatty acids

• Omega-3s → shift the microbiome toward serotonin-supporting species

• Polyphenols → found in berries, cocoa, turmeric, and green tea

00:00 — Welcome & overview of the Anti-Gravity Diet
01:20 — Serotonin as the body’s anti-gravity molecule
04:20 — Microbiome diversity & the gut barrier
06:30 — Babies, serotonin & early gravity resilience
09:40 — Tryptophan, fibre & short-chain fatty acids
11:00 — Leaky gut, inflammation & decoherence
13:00 — Food–mood science & depression
16:40 — What to eat: introducing STACK TEN
17:00 — The ten tryptophan-rich foods
18:50 — Polyphenols, omega-3s & microbiome tuning
19:50 — Beyond diet: exercise, nature, sunlight
21:20 — Balancing sympathetic vs parasympathetic tone
23:00 — Vagus-nerve stimulation & rest-and-digest
24:30 — Gravity as the integrator across biological levels
26:00 — Life as a system for managing gravity
27:20 — Closing reflections & future topics

The Gravity Doctors website: ⁠https://thegravitydoctors.com⁠
Gravitype Quiz: virtualmedicine.org/pull
Dr Brennan Spiegel: brennanspiegelmd.com
Dr Lachlan Kent: lachlankent.au
Book — Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health