Your Brain Is Not Getting What It Needs From You.

← Back to Insights Jacqueline Valk

August 18, 2026 · 4 min read

Your brain is looking for a reason not to help you reach your goals.

Don't give it one.

Here's what that actually looks like, in numbers. A study published last year, using decades of health data on tens of thousands of people, the kind of research that doesn't get done twice, found that if you live past 55, your lifetime risk of developing dementia is 42%. Not the "one in three" figure you've probably heard before. Higher. More than double what researchers thought a few years ago. For women specifically, it's 48%. Just under one in two.

Sit with that for a second, because most people skim straight past a statistic like this. Just under half. Of women. Who live past 55.

Maybe that's your mother. Your sister. You.

Picture the version where you're at your granddaughter's wedding, smiling because everyone around you is smiling, and you can't actually remember why. Picture forgetting the argument you had, so you have it again. Picture your partner explaining, again, gently, who the people in the photos are.

That's not a scare tactic. That's the plain, researched, published cost of doing nothing differently.

Now Here's The Part Your Brain Doesn't Want You To Hear

There's a lever. It's not a drug. It's not a supplement. It's not expensive.

In 2011, researchers took a group of older adults, split them in two, and had one group walk briskly three times a week for a year while the other group stretched. Afterward, they scanned everyone's brains.

The walkers' hippocampus, the part of your brain that runs memory, had grown. About two percent. The stretchers' had shrunk, which is what you'd normally expect with age.

Two percent doesn't sound dramatic until you hear how the researchers described it: reversing one to two years of age-related brain shrinkage. Not slowing it down. Reversing it.

With walking. Three times a week.

So Why Isn't Everyone Doing This?

Because your brain is very, very good at finding you a reason not to. It's tired today. It's raining. You'll start Monday. You've heard "exercise is good for you" so many times it's stopped registering as information and started registering as noise.

That's the trick. Not that you don't know. That knowing has stopped feeling like it applies to you specifically, today, right now.

It does.

Here's The Actual Ask

Not a lifestyle overhaul. Not a gym membership you'll resent by February.

Three walks this week. Just brisk enough that talking is a little harder than usual. That's the entire dose that produced the result above.

Do it today, if you can. Not because I said so, because in five years, you either did or you didn't, and only one of those versions of you gets to say the numbers above weren't about them.

Don't let your brain talk you out of this one. If you want the research and the reminders landing in your inbox instead of relying on willpower alone, join the list, I'll send you what's actually worth acting on, nothing else.

Sources
Nichols, E. et al. (2025). "Lifetime risk and projected burden of dementia." Nature Medicine.
Erickson, K.I. et al. (2011). "Exercise training increases size of hippocampus and improves memory." PNAS.
"Aerobic Exercise Increases Hippocampal Volume in Older Women with Probable Mild Cognitive Impairment" (6-month RCT). PMC.

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