Link: https://youtu.be/bPd9NnOzx78

Duration: 161 min

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Short Summary

This Huberman Lab podcast features an interview with Dr. Tommy Wood, a physician and neuroscience researcher at the University of Washington, chief science officer of BetterBrain, and a 41-year-old master's strongman competitor. Hosted by Stanford neurobiology professor Andrew Huberman, the wide-ranging conversation explores how the brain maintains plasticity and cognitive function with age, covering exercise types, novel cognitive activities, the difference between flow and clutch states, diet/supplementation strategies, dementia prevention (including the surprising shingles vaccine connection), and protocols for concussion recovery.

Key Quotes

1. "They just published a secondary analysis of the active trial that showed that um those who did processing speed training with uh booster sessions at one and three years had a significantly decreased risk of dementia 20 years later." (00:19:18)
2. "what they showed was that that high-intensity interval training group, they improved their fitness just as well as the zone 2 group, interestingly, but they had much better improvements in hippocample function and maintenance of hypocample structure on an MRI scan. And they maintained that benefit for 5 years after the six-month intervention." (01:45:21)
3. "aerobic exercise is gray matter and memory and resistance training is um white matter and more sort of executive type decision-m processing speed type functions." (01:57:53)
4. "stress is actually really important because it's the fundamental driver of adaptation." (01:53:18)
5. "If you want to get better at that skill, you have to work even further beyond your current capacities which which will move you out of flow, right? because of like the friction, the mistakes and the errors that come from that." (00:40:45)

Detailed Summary

Huberman Lab Podcast: Dr. Tommy Wood on Brain Health, Exercise, Nutrition, and Cognitive Aging

Episode Overview and Guest Background

This Huberman Lab podcast features Dr. Tommy Wood, a medical doctor and neuroscience researcher at the University of Washington in Seattle, chief science officer of BetterBrain, and author of The Stimulated Mind. Hosted by Stanford neurobiology professor Andrew Huberman, the wide-ranging conversation explores how to maintain and enhance brain function across the lifespan, with a closing discussion of Dr. Wood's upcoming strongman competition.

• Dr. Wood is a 41-year-old master's strongman competitor, 6'2", typically 210–215 lbs, who competes in masters (40+) and lightweight (under 200 lb) classes requiring a water cut.
• He has competed in 6–7 strongman competitions since starting during COVID at roughly 1–2 per year.
• Huberman announced his first book, Protocols: An Operating Manual for the Human Body, based on more than 30 years of research and 5+ years of writing, available for pre-sale at protocolsbook.com.
• The host suggested inviting Dr. Wood back to discuss recovery from brain injury and stroke in a future episode.

Neuroplasticity Foundations

The conversation opens with the foundational mechanisms of brain change, then builds toward practical protocols. Dr. Wood defines neuroplasticity as the brain responding to inputs by forming new synapses, strengthening existing ones, and pruning or weakening others, with pruning being just as fundamental as addition.

• The adult brain finishes producing new neurons around 2–3 years of age; afterward, refinement happens primarily through removal of connections in response to language, motor, and social exposures.
• Adult neurogenesis is limited to the olfactory bulbs and the dentate gyrus of the hippocampus, and even there the numbers are tiny relative to the whole brain.
• Huberman proposes a developmental theory of aging: late-life cognitive loss partly reflects reduced cognitive and motor inputs that let pruning proceed unchecked.

Aerobic Exercise and the Brain

Different exercise modalities open distinct windows for different types of neuroplasticity and learning. A randomized study of older adults compared three groups: low-intensity work, zone 2 treadmill sessions (3x/week), and HIIT using the Norwegian 4x4 protocol (4 minutes at 85–95% max heart rate, 3-minute rest, four rounds, 3x/week for 6 months).

• The HIIT group improved cardiorespiratory fitness comparably to zone 2 but produced much better gains in hippocampal function and structural preservation on MRI.
• Hippocampal benefits from the six-month HIIT intervention were maintained five years after the study ended, a striking long-term persistence signal.
• Meta-analyses find the best-evidenced protocol for plasticity and learning is a 20–30 minute jog; brief very hard efforts (e.g., 6-second max-effort sprints) produce similar cognitive and arousal benefits, suggesting an area-under-the-curve effect.
• An older-adult aerobic study used brisk walking 3x/week, 40 min/session, for one year, finding increased hippocampus volume, VO2 max, circulating BDNF, and improved memory.
• A standard resistance training protocol cited: 2–3 times/week, 5–6 multi-joint exercises, 3 sets of 8–12 reps at ~80% of max.

Resistance Training and White Matter

Wood emphasizes that 20–30 minutes of resistance training produces acute cognitive bumps similar to a 20–30 minute jog, via mild arousal pathway activation. The longer-term effects diverge markedly from aerobic work.

• 6–12 months of resistance training in older adults produced significant white matter structural changes and improved executive function.
• White matter makes up approximately 60% of the human brain, more than any other species; changes in white matter structure with age are among the best predictors of cognitive decline.
• Aerobic exercise particularly benefits gray matter (including the hippocampus); resistance training particularly benefits white matter.
• IGF-1, elevated by resistance training, is critical for white matter development throughout the lifespan.
• Exercise opens a plasticity window by elevating adrenaline, norepinephrine, and dopamine, regardless of modality (jump rope, sprints, or deadlifts).
• Truly exhaustive exercise (e.g., a 2K rowing test at VO2 max) leaves the brain not working afterward, unlike brief efforts.
• Lactate from high-intensity exercise readily crosses into the brain and stimulates BDNF production, supporting neuroplasticity as the proposed mechanism.

Cognitive Training and Major Trials

Cognitive decline is associated with reduced engagement in demanding activities (lectures, volunteering, reading, crosswords), though such evidence is observational and subject to reverse causation. Several landmark randomized trials anchor the evidence base for brain-protective multimodal interventions.

• The POINTER trial (US, older adults in their 60s–70s) replicates Finland's FINGER trial with diet, exercise, cardiovascular risk monitoring, and brain training.
• The Maintain Your Brain study (Australia, midlife participants in 50s–60s) covers four domains including diet, physical activity, CBT, and brain training.
• The ACTIVE trial (US, 1990s) included memory, reasoning, and processing speed training arms; secondary analysis showed processing speed training with boosters at 1 and 3 years significantly reduced dementia risk 20 years later.
• Processing speed training also improves cholinergic signaling in the forebrain.
• The Brain HQ platform (developed from Mike Merzenich's work) primarily targets processing speed, flashing stimuli in increasingly small windows (hundreds of milliseconds) requiring participants to remember both what and where.
• A Nature-journal analysis of ~1.2 million Implicit Association Test participants found reaction time slowly decreases from around age 30 and further past 60; processing speed is more stable until about 60 before declining.

Novel Activities That Drive Plasticity

Effective cognitive training requires tasks that are both focused and demanding. Per Gloria Mark's work, crosswords and Sudoku are more meditative than cognitively challenging.

• Meta-analyses show ballroom and line dancing have the greatest cognitive effect among activities in older adults because they combine skill learning, social interaction, physical activity, and a musical/timing component.
• Martial arts like Brazilian jiu-jitsu combine physical, complex motor, social, and reactive components.
• Creative and visual arts, language learning, and video games appear to affect brain network stability similarly; visual arts in particular affect the frontoparietal network important for focus and attention.
• No research compares cognitive effects of different musical instruments, so the recommendation is to pick one the person is motivated to learn.
• Wood and colleague Josh Tan propose that cognitive decline partly results from adults ceasing to provide brains with novel and complex inputs; adults' aversion to being bad at things is a major reason they stop seeking such challenges.

Flow vs. Clutch States and Skill Acquisition

Csikszentmihalyi's original flow definition describes being engaged in a task where skill is just below the task's difficulty, producing striving and well-being. Modern usage erroneously equates flow with effortless performance.

• Wood defines flow as maximal expression of a complex learned skill performed at the edge of capability while maintaining function, while a "clutch state" combines optimal arousal with hard cognitive/physical work.
• Flow is not required for learning; learning requires mistakes, friction, and stress, which are not conducive to flow.
• Huberman coins "limbic friction" for the push at the edge of challenge during a clutch state.
• A friend from the special operations community outlined a four-tier skill framework: unskilled, skilled, mastery, and virtuosity (mastery inviting in the unknown at the edge of effort).
• Examples cited include Andy Stumpf (former Tier 1 SEAL, wingsuit pilot, Red Bull High Performance), the Dean Potter documentary The Dark Wizard, Ayrton Senna's Monaco quote, and Twyla Tharp's dancers spending hours on basic drills before formal practice.
• Wood offers a "training thirds" rule: a third of sessions feel great, a third are average, a third just suck and you have to show up.

Focus, Practice, and Cognitive Work Patterns

Hard cognitive work is sustainable in chunks of 20–30 minutes with breaks; the Pomodoro technique (25 minutes work, 5-minute breaks) approximates this rhythm. Published authors reportedly cap solid writing at about four hours per day, with marathon 6–12 hour sessions followed by compensatory output drops.

• Eliminating phone notifications and reducing habitual checking improves focus; even a phone in a bag under a chair unconsciously reduces cognitive flexibility.
• Expert violinists averaged ~10,000 practice hours by age 20, practiced in two 60–90 minute daily sessions, and were still not considered true experts at that point.
• Regular exercise produces cross-stressor adaptation, making people more robust to psychological stress.
• Chronic stress is harmful because the body never gets to adapt; intermittent exposure to stressors drives adaptation while hypostress prevents building function.
• Sleep erosion signals stress levels need adjustment because there is a limit to absorbable stress.
• An athlete's subjective self-reported feeling is a better predictor of performance than HRV or blood tests; the RESTQ questionnaire assesses perceived recovery and motivation.

Subjective Feelings vs. Objective Performance

There is a notable dissociation between subjective feeling and actual performance, particularly relevant when considering stimulants and cognitive enhancers.

• Caffeine makes people feel better but perform worse on complex working memory tasks like the N-back.
• Methylphenidate shows a similar effect in non-ADHD individuals; cannabis users feel more creative but aren't actually more creative.
• Stimulants like caffeine, modafinil, and ADHD medications likely act indirectly by setting the stage for learning rather than directly enhancing learning.
• There is no "plasticity pill"; arousal, alertness, and focus appear to be prerequisites for plasticity rather than direct causes of learning.
• Catecholamines (not endorphins) are the active cocktail behind the "I feel great post-workout" effect, alongside a short-term cortisol bump.

Diet for Brain Health

The MIND diet (Mediterranean Intervention to Prevent Neurodegenerative Delay) emerged from Rush University's memory and aging project, blending Mediterranean and DASH diets and emphasizing seafood, vegetables, berries, whole grains, while limiting saturated fat and animal protein.

• The SMILES trial was the first RCT to show Mediterranean-pattern diets significantly improve depression symptoms.
• A New England Journal of Medicine trial found the MIND diet produced similar cognitive benefits to standard caloric restriction, suggesting the caloric-restriction arm's benefits may reflect overall health improvements rather than specific food choices.
• A UK Biobank study removing individual Mediterranean diet foods (olive oil, meat) found no single component altered the diet's relationship with dementia risk; overall dietary pattern matters more than any one food.
• Energy availability and brain volume form a bell-shaped curve across populations (Bolivian Tsimane hunter-gatherers, intermediate Metan, and industrialized US/Europe), with both chronic caloric restriction and chronic excess linked to smaller brain volume; excess acts via metabolic disease, inflammation, and high blood pressure.

Key Nutrients and Brain Function

Strongest-evidence nutrients for brain health include vitamin D, iron, omega-3 fatty acids, and B vitamins involved in methylation (B12, folate, with possible roles for B6 and riboflavin). Antioxidant polyphenols (berries, coffee, tea, chocolate) and carotenoids (lutein, zeaxanthin, astaxanthin from shrimp/salmon) have supportive evidence.

• Dietary fiber, magnesium, zinc, and structural lipids like choline and ethanolamine (nuts, seeds, eggs) also have supporting evidence.
• Adipose tissue stores long-chain omega-3s and releases them during lipolysis (sleep, exercise) for brain use; consistent seafood consumption across life builds this depot.
• Phospholipid-form omega-3 (krill) gets more into the brain per dose than triglyceride-form (fish), but differences wash out over multiple days because triglyceride-form cycles through fat stores.
• A USC trial showed long-term omega-3 supplementation reached the brain via CSF but produced no cognitive or MRI changes, likely because participants weren't deficient at baseline.

Supplementation Strategy and Blood Tests

The recommended baseline blood tests for brain-relevant nutrients are: vitamin D, hemoglobin/iron, omega-3 levels, and homocysteine. Lab "normal" homocysteine can extend to 15–16, but dementia and cognitive decline risk rises above 13 and probably above 10–11.

• Three RCTs (VITOG/Oxford, B-proof, Omega-AD) show omega-3 and B vitamin status interact: B vitamins lower homocysteine but produce no cognitive benefit unless omega-3 status is adequate.
• Conversely, omega-3 supplementation fails in people with elevated homocysteine.
• The COSMOS study in older adults found a basic multivitamin (Centrum Silver at 100% RDA, no megadoses) produced cognitive improvements; cocoa flavonols only benefited participants with poor baseline diets.
• Omega-3 EPA at 1 g/day is commonly considered good; 3 g/day may be better even within the upper reference range.
• Wood frames a two-tier approach: (1) raising population-level brain health via food quality and equitable access, and (2) pushing individual function higher through targeted testing and supplementation.
• The nutrition and supplementation discourse is characterized as "prehistoric," with the last 40 years focused mainly on harms (trans fats, fried foods, excess calories, alcohol) rather than benefits.

Peptides and Injections

Three popular peptide categories are identified: microdosing retatrutide/tirzepatide for weight/fat loss, BPC-157 for injury repair, and GHK copper for skin appearance (especially popular with women). Most peptides lack quality human evidence of efficacy, with GLP-1s being the main exception.

• BPC-157 specifically has no good human evidence for its recovery thesis.
• Growth hormone secretagogues carry a risk of insulin resistance and diabetes at higher doses.
• Peptide adverse events are largely attributed to botched injections or black-market sources rather than the peptides themselves; melanotan is flagged as especially dangerous.
• Creatine is cited as the best-evidenced supplement: very safe even at high doses in frail older individuals, with potential cognitive or physical performance benefits.
• Omega-3s and magnesium also have reasonable evidence of efficacy.
• A framework from Jeffrey Bland is recommended: ask whether a substance is safe first; documented safety data makes trying it low risk even if efficacy is uncertain.

Dementia Prevention Landscape

Alzheimer's makes up 60–80% of dementia cases; vascular dementia is the next most common and overlaps heavily with Alzheimer's. Potentially half of dementia cases are preventable, with most preventable risk falling into Alzheimer's and vascular dementia.

• Monogenic dominant Alzheimer's mutations in presenilin 1/2 or the amyloid precursor protein gene account for less than 5% (perhaps as little as 1%) of cases.
• APOE is the most common risk gene for late-onset Alzheimer's, but thousands of genes contribute polygenic risk; late-onset Alzheimer's is more related to lifestyle and environment.
• The Lancet Commission (overseen by Professor Jill Livingston) identified 14 modifiable risk factors accounting for ~45% of dementia cases, including early life education, high blood pressure, diabetes, hearing/vision loss, brain trauma, high cholesterol/LDL, low physical activity, and social isolation.
• The Commission omitted sleep deprivation despite comparable evidence; dementia risk rises when people consistently sleep fewer than 6 hours/night due to loss of REM-enriched final cycles (~90 minutes each).
• The Commission also omitted nutrient status (omega-3s, B vitamins); some analyses suggest up to 70% of dementias may be preventable when including socioeconomic factors.

Shingles Vaccine and Dementia Risk

Three natural experiments in Wales (UK), Australia, and Canada showed people eligible for the shingles vaccine had lower dementia risk than those born one day earlier and ineligible, exploiting date-of-birth cutoffs that determine vaccine eligibility.

• A US study found Shingrix (recombinant) associated with lower dementia risk than Zostavax (live attenuated), though both were protective versus no vaccine.
• The protective signal is slightly bigger in women than men; study populations were in their 70s and 80s, while US guidelines recommend vaccination in the mid-50s.
• Kaplan-Meier curves diverge within a couple of months, faster than expected for dementia's natural course, suggesting residual confounding remains a possibility.
• Hypothesized mechanisms include immunomodulatory effects and suppression of herpes simplex virus, which has been associated with Alzheimer's.
• A randomized controlled trial is being planned to test causality more rigorously.

TBI and Concussion Recovery

After concussion, the immediate guidelines are: prevent hyperthermia (cool down quickly, use Tylenol if fever develops), avoid sugary refined carbs (elevated blood sugar correlates with worse outcomes), and avoid alcohol and caffeine (both impair sleep, critical to recovery).

• Hyperthermia worsens brain injury because it widens the gap between energy requirements and production, triggering cell death and neuroinflammation.
• The best creatine trial after concussion was a pediatric study (ages 1–18) at 0.4 g/kg/day; typical gym doses are 3–5 grams (about six capsules).
• Choline (CDP/citicoline) 1–2 g/day has the best evidence among non-creatine supplements.
• Boswellia has been tested in 3 clinical trials showing benefit; Enzogenol (pine extract) has slightly less evidence.
• Ibogaine has emerging data on TBI and brain recovery via neuroplastic effects at macro/psychedelic doses but is illegal in the US.
• Post-TBI guidance has shifted from resting in a dark room to early low-level aerobic activity 2–3 times per week, just below the threshold that worsens symptoms.
• Standard return-to-play sequence: non-specific aerobic → skill-specific exercises → full training → return to play.
• Physical therapy (including vestibular and ocular motor training) is the standard of care for ongoing symptoms a month or more after TBI; eye tracking is increasingly used in professional sports to establish baselines.
• The Adult Changes in Thought study at the University of Washington in Seattle and the Rush Memory and Aging Project showed cognitive function declines stepwise after periods of significant illness, with larger drops after hospitalization.

Strongman Competition Details

Dr. Wood's upcoming strongman competition is scheduled for the end of August and will not be available online, though content may appear on Instagram. Standard regional competitions have 5 events; the Natural World's Strongest Man qualifier has 7 events.

• Farmer's walk: 120 kg (264 lbs) per hand, carried for maximum distance within a 60–90 second time cap.
• Yoke walk: 700 lbs carried for roughly 30 m (90 ft); if completed within the time cap, competitors perform circus dumbbell reps at 110 lb then 135 lb.
• Loading medley: sandbags and kegs over a platform, implements ranging 200–300 lb that increase over time.
• Maximum squat (axle bar): 170 kg (~374 lb) or 200 kg (~440 lb), with shorter athletes potentially gaining an advantage due to less distance traveled.
• Log press: 100 kg (~220 lb) or 120 kg (~264 lb) for reps.
• Sled event with a 275 lb sandbag drag within a time cap.