People Who Want To Keep Their Brains Sharp & Strong As They Get Older Often Do 3 Casually Basic Things

Last updated on Oct 07, 2026

A close-up portrait of a fit mature woman with blonde hair smiling directly at the camera while wearing a purple tank top during a home workout.oneinchpunch | Canva
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If only there were a way to reverse or even just stop the aging process. Sadly, that will probably never be a thing (no matter what that one weird billionaire says), but one expert insisted that we have more control over this than we think we do, at least where our brains are concerned.

It's not just that you slowly (or sometimes not so slowly) begin losing mental capacity as you age; your brain actually gets smaller as you get older, shrinking about 5% per decade after 40, especially in learning- and memory-related regions like the hippocampus and frontal lobe.

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"Most people talk about doing Sudoku puzzles or crossword puzzles, but that is not the key to preventing this shrinkage," said Dr. Kay Linker, a neuroscientist who specializes in the science of aging and longevity.

So what stops this brain shrinkage? Well, it turns out it has a lot more to do with how you exercise your body than how you exercise your intellect. Dr. Linker shared three things you can do to slow down this shrinkage process and hopefully stay spry well into your golden years.

People who want to keep their brains sharp and strong do a few basic things:

1. They exercise in heart-rate zone 2

@dr.kay.longevity Here's how Zone 2, Zone 5, and racket sports can help protect against brain shrinkage:⁠ ⁠ 💧 Zone 2 (low-intensity cardio): Steady-state aerobic exercise promotes the creation of new mitochondria in your cells, improving energy metabolism and overall brain resilience. It also enhances blood flow, providing your brain with essential nutrients and oxygen.⁠ ⁠ ⚡ Zone 5 (high-intensity bursts): Pushing your heart rate to the max triggers the release of brain-derived neurotrophic factor (BDNF)—a protein that supports neural connections and strengthens brain function.⁠ ⁠ 🎾 Racket sports: These activities combine aerobic exercise, quick decision-making, and hand-eye coordination. Research shows they help preserve brain volume in key areas linked to memory and cognition.⁠ ⁠ Together, these forms of exercise target different mechanisms to protect your brain from shrinkage and support lifelong cognitive health. 💪✨⁠ ⁠ ⁠ #BrainHealth#Neuroplasticity#Exercise#Longevity#Cognition#Fitness#Tennis#Zone2#Zone5#BDNF#Mitochondria#Aging#Health♬ original sound - Dr.Kay Linker

Exercise has five heart-rate zones, with zone 2 equating to 60% to 70% of your maximum heart rate capacity. You can calculate your maximum heart rate by subtracting your age from 220 (though note that this can vary, so you should consult your doctor, and this does not constitute medical advice).

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What kind of activity gets you to 60% to 70% of your maximum heart rate depends on myriad factors, but for most people a brisk walk, cycling, swimming, rollerblading, or a machine like an elliptical trainer will usually do the trick. Dr. Linker said women should shoot for 90 minutes to two hours a week, while men should aim for two-and-a-half to three hours. 

"What this does is that it increases mitochondrial biogenesis," and that, in turn, will "improve your hippocampal function," one of those aforementioned brain regions that govern learning and memory.

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2. They exercise in zone 5

As beneficial as zone 2 can be, we also need some of that full-throttle Zone 5 physical activity too; the kind that puts us at 90% to 100% of our maximum heart rate. (Again, capacity varies from person to person, and you should speak to your doctor before starting an exercise habit like this.)

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Thankfully, we only need a little bit. Dr. Linker suggested two 15-minute sessions per week, with 30-second sprints as fast as you can go and one-minute rests in between. Depending on your fitness level and your individual situation, you may need to work up to this, so listen to your body and, again, consult your doctor.

Keeping it to a minimum, however, is key. Too much high-intensity exercise will increase your production of cortisol, the main stress hormone that wreaks havoc on the body and brain when secreted at excessive levels.

"Zone 5 is really important for the brain because it produces something called lactate," Dr. Linker explained, "and it's really useful for neurons to produce more BDNF." That stands for Brain-Derived Neurotrophic Factor, a protein that plays a vital role in growing and maintaining neurons, especially in the hippocampus and prefrontal cortex.

RELATED: 11 Daily Habits Of Women Who Age Slower Than Their Friends

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3. They play racquet sports

If you're looking for a hobby that will help you live longer, join the pickleball craze (or tennis, racquetball, or even badminton). Racquet sports have been repeatedly shown to correlate with longevity. They also correlate with wealth, which also correlates with longevity, for the record.

However, racquet sports and other activities that involve complex motor skills — all that hand/eye coordination, basically — are like a muscle-toning program for your brain, especially as you age.

"[They] really stimulate the cerebellum," Dr. Linker said, "which, although volumetrically, is a small structure, it actually contains quite a lot of neurons. In fact, 80% of our neurons reside there, so when this is functioning at a high level, the rest of your brain is going to follow." See you at the pickleball court, then!

RELATED: Brain Doctor Reveals That People Who Have This One Specific Hobby Tend To Live Longer Than Everyone Else

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John Sundholm is a writer, editor, and video personality with 20 years of experience in media and entertainment. He covers culture, mental health, and human interest topics.

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