Huberman lab is a podcast which covers a wide array of topics, but can be summarized as a “science based self-help podcast”.

Many of the episodes has overlapping information, so I try to summarize everything by topics.

Nervous system & neuroplasticity

• Connection between brain, spinal chord and body. The “puppet master” of all biological processes in our body
• Functions: Sensation, feelings, perception, thoughts, actions
• Reflexive: Automatic responses / actions
• Deliberate: Need to be concentrated / alert
• Neuroplasticity: Change connections between neurons so actions become “reflexive” instead of deliberate
• Plasticity is not the goal, only a step in optimizing, it’s the capacity for our nervous system to change
• Plasticity occurrs in deep-rest or sleep
• Plasticity in adult human nervous system is controlled by neuromodulators (dopamine, serotonin, acetylcholine)
• Epinepherine creates alertness and increased attention (important for learning)
• The goal is to have energy and focus to pursue and energy and focus to suppress action – not flow state

Vision

• Vision involves eyesight but eyes are responsible for mood and level of alertness as well
• To offset nearsightedness: get as much sunlight as you can during the day without sunglasses; avoid light exposure between 10 pm and 4 am, be sure to spend time throughout the day looking off in the distance at farther objects
• Train vision just like you would train other muscles – near/far, smooth pursuit, test eye dominance
• A healthy cardiovascular system delivers blood, oxygen, nutrients to the eyes and brain and supports vision over time
• The brain uses 40-50% of real estate for vision
• Photoreceptors (rods and cones) are responsible for vision: cones are involved in bright daytime vision, rods are involved in dusk or nighttime vision
• You are not actually seeing objects directly – you are making a guess based on the pattern of electricity that arrives in your brain
• Light information is transformed into electrical signals your visual system understands
• Every animal sees the world differently depending on whether they have 1, 2, or 3 cones
• What you experience in the outside world is limited by what wavelengths of light you see
• The most central aspect of our biology is to anchor ourselves in time based on where the sun is
• Protocol for improved alertness: get light in your eyes early in the day and anytime you want to be awake, get blue light exposure early in the day
• Getting two hours per day of sunlight without wearing sunglasses has been shown to have a significant effect on reducing myopia (near-sightedness)
• The brain creates a sense of depth: objects closer look larger and faster objects further look smaller and slower
• Accommodation: eyes dynamically adjust where light lands by moving the lens and changing the shape of the eye
• Eyes and pupils are indicative of things happening deep in the brain
• It’s relaxing to look at things farther away but more work to look at things nearer because the lens have to get thicker to accommodate
• Healthy pupils will dilate when looking at far objects; pupils will shrink when looking at objects up close
• If you are constantly looking at near objects and not allowing muscles to relax, you may be more prone to migraines and are training eyes to look at things close but not far
• Protocol to improve farsightedness: every 90 minutes go to a window and look out at a distance – even better if you can open the window, stand on the balcony, go outside
• Neurons in the brain make it easy or harder to keep eyelids open based on how awake or tired you are
• System of alertness is linked to the position of eyes and can create a wakefulness signal – if you feel tired, look up toward the ceiling and raise your eyes for 10-15 seconds
• Children that sleep in rooms with nightlights are more likely to develop myopia (nearsightedness)
• Viewing light between 10 pm-4 am distorts lens accommodation mechanisms in the eye and suppresses dopamine
• Smooth pursuit: the ability of eyes to track moving objects smoothly through space
• The brain follows eye movements – you can train smooth pursuit to keep muscles strong a few times per week even by watching kids play, watching sports like basketball or tennis
• To improve binocular vision: occlude the healthy eye and force the work to go through the damaged or weaker eye
• Foods rich in vitamin A (dark leafy vegetables and carrots) in raw form can help support vision

Sleep

• Neuroplasticity occurs during sleep
• No deliberate processes - We only work with what’s “inside us”
• Non-sleep deep rest has advantages - 20 min of deep rest accelerates neuroplasticity
• Sleep cycles occur in 90-minute rhythms – you are not in deep sleep immediately, it takes a few minutes of agitation before the body relaxes
• Slow-wave (non-REM) sleep takes place earlier in the night: motor learning, motor skill learning, details about specific events
• REM sleep takes up more time later in sleep: Eye movement, entirely paralyzed
• REM sleep is one of the few times in our life where norepinephrine is absent so there’s no chemical manifestation of fear and anxiety
• may be more important to get consisstent sleep Vs. amount of hours.
• Improve sleep quality: Limit fluids intake before sleep, avoid drugs+alcohol
• Lucid dreaming: Being aware that you dream while you dream
• Ketamine is about becoming removed from the emotion of an experience, mimincs REM sleep
• Light-detecting cells in the eyes => Wakes up naturally if it is light, even if we are not fully rested
• Caffeine right after waking up => endogenous mechanisms for suppressing adenosine are blocked
• Minimize bright light after 10 pm
• The late peak in alertness and activity can last about 45-60 minutes

Learning

• Test learning at different times, to see what works for you. Try to learn in 90-minute blocks
• For learning while alert, the ideal background is quiet or silent, hard task = alertness needed = Learning
• For learning while sleepy or tired: the best scenario is some background noise to trigger autonomic arousal
• Eating shifts us toward state of calm; fasting shifts us toward a state of alertness
• Creativity has two parts: (1) creative discovery mode – more random, facilitated by relaxed and sleepy states; (2) linear implementation mode – facilitated by alertness
• To wake up: get sunlight exposure early, drink water upon waking, exercise within the first three hours of waking

With regards to blocks, this is very common in school, we have 45 minutes blocks and 15 minutes of “freetime”/recess for kids. University lessons are also often structured with pauses. So this is nothing new and common sense.

I do not personally believe that all people learn better at specific times of the day, but it might be the case for some people. I have not experienced learning better at different times of the day.

breathing

• Mouth breathing Vs. Nasal breathing: Nasal breathing better for cosmetics and health
• Nasal breathing is cosmetically optimal for features of the mouth and jaw, and more importantly dilates sinuses, improves lung capacity, and reduces apnea in sleep

Stress

• physiological sigh to calm down: two inhales through the nose followed by an extended exhale through the mouth
• Stress is a system used to make the brain and body to respond
• Stress management: Remain calm when the body is stressed
• Nasal breathing is more advantageous than mouth breathing in many cases
• Short-term stress is good for the immune system
• Stress often comes in the form of bacterial or viral infection so the body’s response is to release epinephrine/adrenaline to combat infection
• Procrastination is how we turn on short-term stress and cue our body to work
• To tolerate medium-term stress, get comfortable with cold shower , sprint and other stress-inducing activities
• Social connection mitigates long-term stress by leveraging serotonin which has positive effects on the immune system and connections in the brain

Hormones - Tetestorone, estrogen etc.

• Hormone: compound released, usually from a gland, that travel and have effects on that gland and other tissues in the body
• Watching sex increases testestorone, having sex increases it even more, being abstinent also increases it
• Becoming a father decreases testestorone, expectant fathers have a 50% decrease in both free and bound testosterone levels
• Aromatase converts testosterone to estrogen => Masculinization of brain, Estrogen sets up masculine circuitry in the brain, testosterone controls the display of behaviors
• Estrogen sets up masculine circuitry in the brain, testosterone controls the display of behaviors
• Testosterone and estrogen can travel into cells and interact with the DNA of cells to control gene expression
• A hormone has to be able to bind the receptor and take action on target cells to be effective
• Wiki: The endocrine system is a messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system
• Hormones have two categories of effects: fast and slow in terms of the effect on genes
• Fast-acting hormones: cortisol, adrenaline
• Slow-acting hormones: testosterone, estrogen – generally long term effects, though can have quick effects as well.
• Pot smokers have a higher rate of development of gynecomastia (male development of breasts)
• Creatine promotes balding in some males because of its effects on dihydrotestosterone
• You have to breathe properly to get sleep to avoid apnea states which can adversely impact sex hormone levels
• Major sources of estrogen and testosterone: ovaries for estrogen and testes for testosterone (though adrenals can also make testosterone)
• Testosterone fluctuations: low pre-puberty, high puberty, drops off at a rate of ca. 1% per year
• Men who have sex have 70% increases in testosterone
• Order of training: when endurance activity is performed first, it leads to decreased testosterone
• Libido in females: increases in estrogen promotes receptivity to mating
• After ejaculation, there’s a release of prolactin which activates a refractory period in which male can’t have sex for a given length of time

Metabolism

• Metabolism is the consumption of energy and use of energy in the cells of the body for growth, repair, and maintenance of tissues
• 75% of metabolic needs come from the brain, Muscle burns more energy than fat
• Metabolic functions include repair of injury and brain tissue, clearance of damaged neurons, and energy for cells – not just BMI and weight-related concerns
• Thyroid and growth hormones have similar pathways and are both critical to metabolism and repair and growth of tissues
• Iodine, L-tyrosine, and selenium (found in Brazil nuts) are all important for proper thyroid hormone production and function
• Some “clean” diets can interfere with thyroid functions by disrupting iodine pathway – plant-rich hard diets make it challenging to get enough L-tyrosine; with a carnivore diet it is hard to get enough iodine
• Growth hormone release peaks in puberty and decreases 2-3 fold between 30s-40s
• Lifestyle activities to increase growth hormone: (1) increase slow wave/deep sleep; (2) exercise 60-75 minutes – but not working to failure which increases cortisol
• Most hormones we make have been synthesized and are available by prescription or on the market but use with caution – any time you intake an exogenous hormone, your body stops producing on its own
• The thyroid hormone controls many features of the face and eyes but its main role is to promote metabolism and convert energy
• Iodine (found in table salt) works with L-tyrosine to produce T3 and T4 thyroid hormones
• Sauna has a profound effect on decreasing cortisol and releasing growth hormone, increasing 16-fold (that’s 1,600%): (1) sauna between 176F-210F; (2) 20-30 minutes in duration then rapid cooling, repeat

Endurance

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Muscles

• The ability to isolate and contract muscle hard will tell you about the ability to grow that muscle
• Weight training and resistance training is used for two distinct purposes: (1) systemic effects or (2) isolating muscle
• To increase muscle growth something needs to happen to trigger muscle tissue to change: either stress, tension, or damage
• One of the most predictive markers of aging is the ability to jump and the ability to stand up quickly
• The better you are at contracting and isolating muscles, the faster you will get desired effects to those muscles
• To get stronger, slow down and increase time under tension to isolate the muscle and encourage hypertrophy
• Change up regime: the nervous system adapts quickly at the beginning but slows with time
• To improve strength training performance and muscle growth: (1) stay hydrated with adequate salt and electrolytes; (2) consume creatine daily; (3) consume beta-alanine; (4) ingest sufficient leucine from high-quality protein
• Three tests to assess systemic recovery: (1) heart rate variability; (2) test grip strength in the morning; (3) test carbon dioxide tolerance first thing in the morning
• Muscles are essential for maintaining how we breathe, how we move, metabolism, and posture
• The more muscle you have, the higher your metabolism
• The nervous system controls muscle through three areas of control: upper motor neurons, lower motor neurons, central pattern generators
• Upper motor neurons: send signals to the spinal cord to direct activity to muscles
• Lower motor neurons: send axons to muscles and cause contraction through acetylcholine
• Central pattern generators: rhythmic, reflexive movements
• Muscles function on glycolysis, the breakdown of glycogen and glucose into energy
• Glucose and glycogen breakdown into pyruvate – in the presence of oxygen (in the muscle), more energy will be generated
• 10% of the time you should exercise to lactic threshold (when you feel the burn) to enhance function of organs
• Benefits of lactate are only in the presence of oxygen so breathing is critical when you reach the point of burn
• Muscles get bigger as myosin (protein) gets thicker
• Muscles can get stronger without getting bigger – however, increasing the size of the muscle almost inevitably increases strength
• Always work within the full range of motion
• Carbon dioxide tolerance is an indicator of whether the system as a whole is working properly and measures your ability to mechanically control the diaphragm
• Cold (cold plunge or ice bath) after resistance training seems to short circuit some of the benefits of training: reduces inflammation and muscle soreness – but does seem to interfere with mTor pathways

Hunger, eating, fasting

• Hormones are involved in both the desire to eat and satiety or reduction in appetite
• Emulsifiers in highly processed foods limit the gut’s ability to identify what is in the food and send satiety signal to shut down hunger
• Neurons in the gut that sense sugar trigger the release of dopamine and encourage you to eat more sugar
• The order you consume macronutrients influences blood glucose levels: carbs and fat early in meal give rise to blood glucose; eating fibrous vegetable first will blunt glucose increase
• Managing blood glucose plays a critical role in managing cholesterol as well
• Over the counter supplements that have been shown to decrease blood glucose: berberine, ginseng, magnesium, apple cider vinegar and acidic foods, yerba mate, chromium
• Ghrelin is released from the GI tract and increases the desire to eat by stimulating neurons that increase hunger and anticipatory signals
• Cholecystokinin (CCK) released by the gut has a powerful effect in reducing appetite
• Blood sugar needs to be kept in a certain range
• If glucose gets too high, neurons can be damaged or killed causing loss of sensation in hands, feet, and eyes
• Blood glucose levels can be heavily modulated by moving and exercise before eating
• cholesterol: Want LDL to be low and HDL to be high

Neuromodulators

• Acetylcholine: tends to modify and amplify brain circuits associated with attention and focus
• Norepinephrine: tends to modify circuits associated with alertness and desire to move
• Serotonin: released and modifies circuits associated with bliss and remaining still
• Dopamine: released and associated with amplification of pursuing goals, pleasure, and reward

Drugs and supplements

• Huberman is very cautious in his recommendations and always give a “disclaimer” if he recommends something
• All drugs have side-effects. Drugs that generates X (for example dopamine), can disturb the natural production of X
• Psychedelics => Areas of brain communicate more broadly, hazardous if not working with a professional
• The drugs given to treat ADD and ADHD in kids (like Adderall) have amphetamine-like properties

My take: Do not use “anything”, not worth the risk. Maybe vitamin D if you know you get too little through food / sunlight.

Immune system

• Acute inflammation response => Allows body to repair tissue
• Tummo breathing => Consciously control autonomous nerve system, Wim Hof example. => Liberate adrenaline
• Wim Hof breathing and ice baths release adrenaline which can counter infection

Injuries

• Ice numbs area of injury, but also has negative effects like restricting movement out of injury site
• Heat can improve the viscosity of tissues and improve blood and damage out of the area
• Sunlight may be as effective as red light

Dopamine and motivation

• Dopamine is involved in wanting – not having – the excitement or anticipation about something increases dopamine firing 30-40x
• Dopamine motivates you to take action toward the thing you want, novelty is the number one trigger
• A subtle feature about the dopamine system: for every bit of dopamine that’s released, there’s a crash associated when prolactin is released
• Dopamine make us focus on things outside of us that we have to chase; serotonin makes us content with the here and now
• To maintain motivation, try intermittent reward: celebrate successes every other time
• Just thinking about the activity can sometimes release as much dopamine as the actual act of whatever you’re craving
• Reward-prediction error = actual amount of dopamine released in response to something – the amount expected. Steering expectations
• Viewing bright light in the middle of the night blunts dopamine and suppresses activation of the reward system