Essentials: Breathing for Mental & Physical Health & Performance | Dr. Jack Feldman

Nov 13, 2025 Episode Page ↗
Overview

Dr. Jack Feldman, PhD, a Distinguished Professor of Neurobiology at UCLA, discusses the mechanics and neural control of breathing. He explains how breathing patterns influence mental states, offering tools like box breathing for performance and magnesium L-threonate for cognitive health.

At a Glance
8 Insights
49m 45s Duration
14 Topics
6 Concepts

Deep Dive Analysis

Breathing Mechanics and Neural Initiation of Breath

Nose vs. Mouth Breathing Differences

Active Expiration and the Retrotrapezoid Nucleus

Diaphragm's Evolutionary Role and Lung Efficiency

Physiological Sighs: Function and Frequency

Drug Overdose, Gasps, and Auto-Resuscitation

Slow Breathing Practice and Fear Conditioning in Rodents

Mechanistic Science Validating Breathwork Benefits

Breathing's Influence on Emotional and Cognitive States

Carbon Dioxide Levels, Hyperventilation, and Anxiety

Breathing, Emotion, and Autonomic Processes Coordination

Practical Breathwork: Box Breathing and Other Styles

Magnesium L-Threonate for Cognitive Enhancement

Clinical Trial Results for Magnesium L-Threonate

Pre-Bötzinger Complex

This is a small region in the brainstem, containing a few thousand neurons, that acts as the primary source for generating the rhythm of breathing. Every breath begins with neurons in this complex becoming active, which then connect to motor neurons controlling the diaphragm and intercostal muscles for inspiration.

Retrotrapezoid Nucleus

This is a second oscillator in the brainstem, located near the facial nucleus, involved in generating active expiration. While initially thought to be a central chemoreceptor sensing carbon dioxide, it appears to control expiratory muscles, a function possibly evolved from facial muscle control in more primitive creatures.

Diaphragm

The principal muscle for inhalation in mammals, located just below the lungs. Its contraction pulls it down, expanding the lungs and creating a pressure drop that draws air in. Mammals are unique among vertebrates in having a diaphragm, which provides an extraordinary mechanical advantage for efficient oxygen exchange.

Alveoli

These are tiny, fluid-lined air sacs in the lungs where oxygen exchange occurs across the alveolar capillary membrane. There are hundreds of millions of alveoli, providing a vast surface area for oxygen to passively transfer from the air into the bloodstream and carbon dioxide to transfer out.

Physiological Sighs

These are involuntary deep breaths that occur approximately every five minutes. Their purpose is to pop open collapsed alveoli in the lungs, maintaining the lung's surface area for efficient gas exchange and overall lung health, as normal breaths are insufficient to re-inflate collapsed alveoli.

Long-Term Potentiation (LTP)

LTP refers to the strengthening of signals between neurons, which is a key mechanism underlying learning and memory. Studies showed that increasing magnesium levels can enhance LTP, suggesting a role in neuroplasticity and cognitive function.

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Why do we need to breathe?

We breathe to take in oxygen for body metabolism and to expel carbon dioxide, a byproduct of metabolism. Regulating carbon dioxide is crucial because it affects the blood's acid-base balance (pH), which all living cells are highly sensitive to.

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What is the primary muscle for inhalation and how does it work?

The diaphragm is the principal muscle for inhalation. When it contracts, it pulls down, expanding the lungs and the thoracic cavity. This lowers the pressure inside the lungs, causing air to flow in from the higher pressure outside the body.

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What is the difference between nose and mouth breathing?

At rest, nasal breathing is typical because the nasal cavities can easily manage normal airflow. However, during exercise or when ventilation needs to increase, mouth breathing is used because the larger airways allow for much greater airflow.

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Why do we sigh, and how often does it happen?

We sigh approximately every five minutes to prevent the collapse of tiny air sacs (alveoli) in the lungs. A normal breath isn't enough to re-inflate collapsed alveoli, but a deep sigh provides the necessary pressure to pop them open, maintaining the lung's crucial surface area for oxygen exchange.

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How does breathing influence emotional and cognitive states?

Breathing influences brain state through several mechanisms, including olfactory signals from nasal airflow, vagus nerve signals from lung expansion, and changes in carbon dioxide levels affecting brain pH. Additionally, the volitional control involved in breath practices sends signals that can influence emotional centers.

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Can carbon dioxide levels affect anxiety?

Yes, hyperventilation can lower carbon dioxide levels, which can lead to anxiety. Training individuals to breathe slower and restore normal CO2 levels has been shown to provide relief from anxiety.

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Can magnesium supplementation improve cognitive function?

Research with magnesium L-threonate suggests it can enhance cognitive function by increasing magnesium levels in the brain, which in turn strengthens synaptic connections (long-term potentiation). A human study showed significant cognitive improvements in individuals with mild cognitive decline.

1. Practice Deliberate Slow Breathing

Engage in deliberate slow breathing practices for 30 minutes a day for four weeks to potentially reduce fear responses, disrupt negative neural circuits, and improve emotional and cognitive function, as shown in mechanistic studies.

2. Supplement with Magnesium Threonate

Consider supplementing with magnesium threonate to potentially enhance cognitive function, improve learning and memory (LTP), slow cognitive decline, and improve sleep, as it effectively crosses the gut-blood and blood-brain barriers.

3. Implement Box Breathing

Practice box breathing (5-second inhale, 5-second hold, 5-second exhale, 5-second hold) for 5-20 minutes, especially after lunch, to improve focus and combat post-lunch cognitive decline.

4. Slow Breathing for Anxiety

If prone to anxiety or hyperventilation, practice slow breathing to restore carbon dioxide levels back to normal, which can provide relief from anxiety.

5. Optimize Nasal vs. Mouth Breathing

Breathe through your nose at rest for normal air flow, and through your mouth during exercise when ventilation needs to increase significantly to move more air.

6. Allow Physiological Sighs

Recognize that your body naturally performs physiological sighs (a deep inhale) about every five minutes to pop open collapsed alveoli and maintain lung health; allow or perform these deep breaths when needed.

7. Drink Matina Yerba Mate

Drink Matina yerba mate as a caffeine source for smooth energy without jitters, and for potential benefits like blood sugar regulation, improved digestion, and mild appetite suppression.

8. Take AGZ for Sleep

Take AGZ 30-60 minutes before sleep to improve sleep quality and depth, and wake up feeling refreshed, as it contains clinically supported sleep-supporting compounds.

My mice don't believe in the placebo effect. And so if we could show there's a bona fide effect in mice, it is convincing in ways that no matter how many human experiments you did, the control for the placebo effect is extremely difficult in humans. In mice, it's a non-issue.

Dr. Jack Feldman

I would say a key step in the ability to develop a large brain that has a continuous demand for oxygen is the diaphragm. Without a diaphragm, you're an amphibian.

Dr. Jack Feldman

I think that the notion is that I would like to see more people exploring this. And to some degree, as you point out, 30 minutes a day, some of the breath patterns that some of these styles like Wim Hof are a little intimidating to newbies. And so I would like to see something very simple that people, what I tell my friends is, look, just try it five or 10 minutes. See if you feel better. Do it for a few days. If you don't like it, stop it. It doesn't cost anything.

Dr. Jack Feldman

At my age, I'm not looking to get smarter. I'm looking to decline more slowly.

Dr. Jack Feldman

Box Breathing

Dr. Jack Feldman
  1. Inhale for five seconds.
  2. Hold breath for five seconds.
  3. Exhale for five seconds.
  4. Hold breath for five seconds.
A few thousand
Number of neurons in human Pre-Bötzinger Complex Located on either side of the brainstem, working in tandem to initiate breath.
400 to 500 million
Number of alveoli in human lungs These tiny air sacs provide a vast surface area for gas exchange.
One-third the size of a tennis court (approx. 70 square meters)
Surface area of lung membrane This large membrane must be expanded with every breath.
Two-thirds of an inch
Diaphragm movement during inhalation Sufficient movement to expand the lung membrane and move air.
Approximately 2.5 liters
Volume of air in lungs at rest Baseline lung volume.
500 milliliters (half a liter)
Volume of air in a normal breath Increases lung volume by 20% with each breath.
From 40 to 100 millimeters of mercury
Oxygen partial pressure in bloodstream (after breathing) Change in oxygen levels due to efficient gas exchange in the lungs.
About every five minutes
Frequency of physiological sighs Involuntary deep breaths to re-inflate collapsed alveoli.
30 minutes a day for four weeks
Duration of slow breathing practice in mice Protocol that significantly reduced fear responses in mice.
8 years on average
Cognitive age improvement with Magnesium L-Threonate Observed in a placebo-controlled, double-blind study of humans with mild cognitive decline after three months.
51 years
Biological age of subjects in Magnesium L-Threonate study Their cognitive age was initially 61 years.