Hello Reader!

I wonder if Sudoku would've become my habit (minor obsession?) if I hadn't believed it was helping keep my brain sharp.

For decades we've been told to protect our brains by doing brain things—crossword puzzles, Sudoku, brain-training apps, and learning another language. Not only do they help, I’ll admit to enjoying all of them (except Lumosity’s spatial orientation game—my poor penguin spends most of its time shuffling in a corner).

But what if we've been thinking about brain health too narrowly? A growing body of research suggests that your brain is paying just as much—if not more—attention to what's happening in your muscles, metabolism, and overall physical health. ​
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If that’s true, then I believe we need to stop asking, "How do I exercise my brain?" and instead ask, "How do I build the healthiest body I can?"

Your brain isn't floating around by itself We tend to think of the brain as the command center that tells our body what to do, but the communication goes both ways. Your muscles, hormones, immune system, blood vessels, and metabolism are constantly sending information back to your brain. Researchers are discovering that these signals influence far more than physical health—they also affect how well our brains age. ​ One recent study looked at thousands of adults and found that people with low handgrip strength had significantly higher odds of cognitive impairment and probable dementia than those with stronger muscles.​ ​ Certainly this doesn't mean squeezing a tennis ball all day will protect your memory. But grip strength is a proxy for estimating overall muscle strength and it’s a surprisingly powerful snapshot of what's happening throughout the body.

Your muscles may be doing much more than helping you stand up from a chair

Another fascinating study took an entirely different approach. Researchers analyzed thousands of tiny molecules circulating in people's blood and found patterns that predicted whether someone's brain appeared biologically older or younger than expected.

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One of the strongest signals came from glucose metabolism. People whose bodies handled glucose less effectively tended to show signs of faster brain aging and greater risk for several neurological diseases.

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That caught my attention because one of the biggest "users" of glucose in your body isn't your brain—it's your muscles. Healthy muscle tissue helps pull glucose out of your bloodstream and put it to work, which means every time you build and maintain muscle, you're doing something that supports your metabolic health—and metabolic health appears to matter quite a bit to your brain.

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Scientists are still figuring out exactly how all these pieces fit together. But the message is becoming increasingly consistent: Your brain pays attention to what's happening in the rest of your body.

This changes the goal

I'm still going to encourage you to learn a new language (I’ve been practicing French with Sudoku for years), read novels, play an instrument, and do Sudoku if you enjoy it. In other words, challenge your mind in every way you can.

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But don't overlook what research is showing is a very important way—build and maintain your muscles. Do resistance training. Practice getting up off the floor. Take walks. Jump up and down. Build muscles that help you carry your groceries, climb stairs, and say yes to the life you want. Because those same muscles may also be helping create the conditions for a healthier brain.

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I think that's a much more exciting reason to get stronger than fitting into smaller pants.