Speaker
Tommy Wood
Appearances over time
1 episodes
Episodes
1
Podcasts
Quotes & moments
The 10,000 hours figure was simply the average practice time of expert violinists by age 20 — they weren't even experts yet, and the number doesn't translate to a universal rule of expertise.
Expert violinists in the Ericsson studies tended to practice in 2 sessions of 60–90 minutes per day — a rhythm Wood says is about as much hard cognitive work as most people can sustainably do.
Older adults who did the Norwegian 4x4 HIIT protocol 3 times a week for 6 months showed superior hippocampal improvements over zone 2 exercisers, and maintained those benefits 5 years later.
The Lancet Commission on Dementia Prevention identified 14 modifiable risk factors that together account for approximately 45% of dementia cases — and some analyses suggest the figure could be as high as 70%.
In a dataset of ~1.2 million people, reaction time declined slowly from the 30s onward, but processing speed remained relatively stable until about age 60, then dropped sharply.
Aerobic exercise primarily benefits gray matter structures like the hippocampus (memory), while resistance training primarily improves white matter structure and executive function.
Natural experiments in Wales, Australia, and Canada consistently showed that people who received the shingles vaccine had a significantly lower risk of dementia compared to those who did not.
While lab normal ranges for homocysteine go up to 15–16, cognitive decline risk is elevated above 13 and likely above 10–11 μmol/L — a meaningfully lower target than standard reference ranges.
At least 3 randomized controlled trials show that omega-3s and B vitamins are interdependent — supplementing one without adequate status of the other produces no measurable cognitive benefit.
A pediatric TBI trial used 0.4 grams of creatine per kilogram of body weight per day — roughly double a standard loading dose — and showed significant benefits after concussion.
The Adult Changes in Thought study showed that cognitive decline is not linear with age but occurs in stepwise drops after significant illness, with hospitalization causing the largest decrements.
Meta-analyses of interventions in older adults show that ballroom and line dancing have the greatest effect on cognitive function among activity-based interventions, combining motor skill, social interaction, and music.
White matter makes up approximately 60% of the human brain — a higher proportion than any other species — and its degradation with age is one of the best predictors of cognitive decline.
Studies comparing Bolivian hunter-gatherers to industrialized populations found a bell-shaped curve between caloric availability and brain volume — both chronic caloric restriction and caloric excess shrink the brain.
Data on sleep and dementia risk consistently show that the threshold for elevated risk is approximately 6 hours of nightly sleep — those consistently below this level face significantly increased dementia risk.
The adult brain does not meaningfully grow new neurons — but it constantly rewires existing ones. Neuroplasticity is the brain's core survival mechanism, and conflating it with neurogenesis has misled people into thinking the adult brain can't change.
Continuing hobbies you already know slows decline, but randomized trials show that only genuinely novel cognitive challenges actually improve function. Crosswords have a meditative effect; learning a new language or dance has a plasticity effect.
Visual processing speed training — where flashed images must be remembered in decreasing millisecond windows — with booster sessions at years 1 and 3 significantly reduced dementia risk 20 years later. This is one of the strongest long-term cognitive training results ever published.
Meta-analyses of interventions in older adults show that ballroom and line dancing produce the greatest improvements in cognitive function. Unlike digital brain training, dancing combines motor skill acquisition, social interaction, musical timing, and physical exercise — hitting multiple neural networks simultaneously.
Expert violinists practiced in two sessions of 60–90 minutes per day — that's about the sustainable limit for hard cognitive work. The brain can only genuinely focus for 20–30 minute chunks, which is why the Pomodoro technique accidentally got it roughly right.
People become so habituated to a pattern of constant interruption that when no distraction arrives, they reach for their phone anyway to create one. The good news: you can train yourself out of this pattern with sustained distraction-free periods.
Aerobic exercise primarily benefits hippocampal gray matter and memory through BDNF and lactate. Resistance training primarily strengthens white matter and executive function through IGF-1. These are complementary, not interchangeable — you need both.
A study of older adults compared low-intensity exercise, zone 2 cardio, and the Norwegian 4x4 HIIT protocol. HIIT produced far superior hippocampal improvements — and those benefits persisted 5 years after the 6-month intervention ended. More cortisol released meant better outcomes.
Natural experiments in Wales, Australia, and Canada — where eligibility switched based on birth date — consistently showed lower dementia rates among shingles vaccine recipients. The newer Shingrix vaccine appears more protective than the older Zostavax. The leading hypothesis is an immunomodulatory effect that may also suppress other neurotropic herpesviruses.
The Adult Changes in Thought study and the Rush Memory and Aging Project both showed that cognitive decline is not smooth — it drops in steps after major illnesses, with hospitalizations causing the largest drops. Minimizing severe illness is a genuine brain-preservation strategy.
For mild-to-moderate concussion: avoid heat, avoid alcohol, control blood sugar. Creatine at loading doses, magnesium 400mg 1–2x/day, and omega-3s have the best evidence. CDP-choline at 1–2g/day and Boswellia extract also have clinical trial support. Return to aerobic activity as soon as tolerated — rest is no longer the standard of care.
Three randomized controlled trials show that omega-3s and B vitamins are synergistically dependent — neither produces cognitive benefit without adequate status of the other. Most omega-3 and B vitamin trials fail because they don't account for this interaction, leading to false conclusions that neither nutrient works.
Studies using the N-back task show caffeine users feel like they're performing better while actually making more errors. The same dissociation appears with methylphenidate in non-ADHD individuals. Exercise-induced arousal doesn't create this problem — which makes it the superior cognitive enhancer.
Elite performers know that a third of training sessions feel great, a third are average, and a third are terrible — and that's normal, not a sign of failure. Expecting learning to feel effortless all the time is what gets people to quit.
Tommy Wood — neuroscientist, brain health expert, and drug-tested Masters strongman — describes competing in natural World's Strongest Man at 41: farmer's walks at 264 lbs per hand, 700-lb yoke walks, and log press at 264 lbs. His own life is an argument for the combination of physical and cognitive challenge across the lifespan.
Analysis
What they talk about
- Health & Fitness 55%
- Education 18%
- Sports 18%
- Society & Culture 9%
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