Amazon link
Official book site
The Tim Ferriss podcast interview where I learned of Wood

This book, subtitled “Future-Proof Your Brain from Dementia and Stay Sharp at Any Age”, shares the latest academic research on how to improve your brain’s performance while combining it with the practical tips Wood has developed as a coach to world-class athletes. Dr. Wood has both a medical degree and a PhD in neuroscience, and is an athlete himself in strength and endurance competitions.

The not-so-surprising conclusion: if you want to lower your chances of dementia, you need to improve your brain’s performance today, which comes from stimulating both your body and your brain.

The need for stimulation arises because of two separate phenomena:

• The brain and body are efficient. If you stop using a function, the body adapts to invest less resources in that function. So if you use your brain less, the brain gets less blood and oxygen because the body doesn’t want to waste precious resources on something that’s not valued.
• Growth and adaptation comes from the cycle of stress and recovery. Our muscles grow when we rest after pushing them through weight-lifting or exercise. Our brains grow when we sleep after pushing them to learn new things or tackle difficult cognitive problems. Admittedly, perpetual stress with no recovery will be damaging, but no stress will lead to deterioration as the brain and body aren’t used. As he puts it, “The stress response is the body reacting to the internal or external environment when it notices that something needs to change. It then kicks off the processes required to create that change, resulting in adaptation.” That’s how our muscles grow, how our immune system fights off infections, and how our brains learn new skills. In other words, stress can be a good thing, leading to growth and change.

Wood recommends a Three-S approach to improving the brain’s functionality:

1. “Stimulate – cognitive demand or challenge through social or mental activities
2. Supply – the energy, oxygen, and important nutrients that allow us to respond to stimuli
3. Support – the processes of neuroplasticity, maintenance, and repair that occur during rest and sleep”

This creates “a virtuous cycle: if you improve function, you’re able to expose yourself to a wider range of stimuli. By exposing yourself to more stimuli, you improve function even further. Just like lifting weights – the stronger you get, the more you can lift, and the more you can lift, the stronger you get. Repeat.”

The rest of the book is pretty standard health advice, and echoes Peter Attia’s advice in Outlive.

Exercise. You need a balance of strength training (2-3x/week), cardiovascular activity (every day), high-intensity aerobics (30 minutes 1-2x/week). But he reminds us that everything counts. He recommends sprinkling movement “snacks” throughout the day: a minute of jumping jacks or squats between meetings, taking the stairs, standing instead of sitting during a meeting. Use your body for movement more (aka “Propel”). It’s not about doing max effort workouts every day – in fact, that won’t work because your body will not have a chance to recover and adapt. But it’s about shifting the balance towards more activity (aka “Sit less”).

One particular recommendation that stuck with me is the Norwegian 4×4. This is an activity where you run all-out (90+% of your max heart rate) for 4 minutes, then rest and recover for 4 minutes (walking), then repeat for 4 total cycles (32 total minutes). When a group of senior citizens did this three times a week for six months, they had measurably improved heart functioning (and memory improvements) even four years later. He notes that any kind of sprint training, even for 20-30 seconds at a time, will have benefits. That has encouraged me to commit to running more consistently to get those heart and memory benefits.

Wood summarizes his diet advice as “Maximize brain-boosting nutrients” (vitamin B, vitamin D, Omega-3, folates, zinc, iron, polyphenols, choline) and “Fuel for your needs” (“You need enough energy to build brain buffers and maintain cognitive function with age, but taking too much fuel on board can impair long-term health and performance”). The latter is particularly important as you exercise more; again, the body is efficient, so if you don’t have enough fuel, it will route the energy towards the functions that have the greatest need, which means your brain may get starved. Eat enough for your level of activity, but try to minimize the processed food and sugars, and eat more protein instead.

With those basics in place, improving your brain functionality depends on stimulation, such as learning new skills and social connection (tracking social interactions requires a lot of brainpower!). He particularly recommends activities that combine brain and body and social stimulation e.g. group dancing or team sports, as those stimulate many aspects of the brain and body at once and create synergistic effects as a result. He says one of the dangers of retirement is that people whose primary mental stimulation came from work can have their brains start to shut down without deliberately seeking new experiences to replace that stimulation; “If we stop giving the brain those inputs, it thinks those functions aren’t needed anymore. Our brains then stop maintaining themselves, and their function deteriorates.”

But it doesn’t really matter how we stimulate the brain: “Dancing, martial arts, music, brain training, video games, etc. — it probably matters less what you pick, so choose a creative art, physical activity, or complex skill that requires focused attention and rapid information processing. The goal is to progressively challenge your cognitive muscles and then maintain practice to keep those skills and networks sharp.”

One last recommendation that I found helpful is to intentionally design your day to spend time in different gears. High-gear stimulation would be deep thought work, or sprinting or weightlifting. But for that stimulation to translate into growth and adaptation, we need significant rest and recovery time for our brains and bodies to respond to those stressors. This is consistent with the deliberate practice research of Anders Ericsson, who observed that professional athletes and musicians practiced 2 hours in the morning (stimulate), then ate lunch and napped (supply and support), then 2 hours in the afternoon (stimulate).

As an aside, Steve Yegge, who’s pushing the edge of what’s possible with AI orchestration, came to a similar conclusion: AI is “automating the easy work, and leaving us with all the difficult decisions, summaries, and problem-solving. I find that I am only really comfortable working at that pace for short bursts of a few hours once or occasionally twice a day, even with lots of practice. So I guess what I’m trying to say is, the new workday should be three to four hours. For everyone.”

What Wood warns against is spending too much time in middle-gear stress, which, unfortunately, is most jobs involve. Not deep thought, not relaxation, just constant meetings and emails and Slack messages keeping us constantly on edge: “a classic signature of the middle gear is constantly switching between tasks. Though much of this sort of cognitive work is ultimately important, most of our middle-gear time is spent doing work that makes us feel busy but isn’t actually work.”

Instead, “A good workday or workweek, just like a good training program, should include a balance of activities – with different intensities that drive different adaptations while providing enough time for recovery.” “The goal is to balance stimulus with recovery while minimizing the factors that interfere with those processes” so that we can build “a foundation for focused work or performance”.

While I appreciated Wood’s advice, I can’t recommend reading the book. This summary gives you most of what you need to know, and Wood’s guest post on Ferriss’s blog on what you can do to reduce your chances of developing dementia will fill in the rest. I ended up skimming a lot of the second half of the book, as it reiterated the recommendations I’ve read in other books and have mostly implemented in my own life (exercise more, eat more vegetables and protein and less carbs, keep challenging yourself, sleep better, etc.). If scientific studies would be convincing to you, this might be a good book to read (check out his exhaustive list of references online), but I didn’t find his writing that engaging, even though I appreciate his perspective.