Exercise Is Medicine for the Brain

Wordle may be a step in the right direction, but did you know that physical fitness can also create new neurons and even restructure the shape of your brain? A local brain health professional breaks it all down. (Spoiler alert: 15 minutes a day keeps the gray matter away.)

by Mpls.St.Paul Magazine 

For a long time, the scientific community held the belief that our big, beautiful brains were unchangeable. At some point, they said, we would just stop growing neurons and, well, the pathways we carved along the way were there permanently. Fixed in place. With no room for growth.

But research and studies recently overturned this long-standing theory. “In neurology, [for years] we always talked about how the brain couldn’t change and that we didn’t grow new neurons … but at the same time, we could learn new hobbies or language. There was such a disconnect there!” says Michael Hennes, DC, of Northwestern Health Sciences University’s Sweere Clinic. “If we learn something new, then our brain has to have changed in some way.”

A specialist in traumatic brain injuries, Hennes has been an eyewitness to this phenomenon in his practice. “Neurological rehab is cool because we can make changes [to the brain] really fast; but if something is only done once, it’s a party trick,” he says. It takes 15 consecutive minutes of activity for your brain to learn something new, the threshold for neuroplasticity (i.e., the brain’s ability to form new neural connections over time). If we only engage in flashcards or mind maps or Duolingo every once in a blue moon, it doesn’t really leave a lasting effect.

“If we do something over and over the course of weeks or months, we get long-term potentiation—meaning, permanent changes happening within the brain,” Hennes says. “It takes some time and patience, but that’s how we make things stick.” If we don’t make a point to stimulate neurons or individual brain cells, they’re going to essentially die off or prune themselves away.

What’s Good for the Body Is Good for the Mind

Wordle, reading, and crossword puzzles aren’t the only way to get your brain to open up new file cabinets. Another surefire way to keep brain matter stimulated is through actual physical movement. Exercise is considered a form of mental stimulation, garnering positive mind-body effects.

One of the biggest benefits of exercise for the brain is that it promotes brain-derived neurotrophic factors (BDNF), which, Hennes says, basically works like fertilizer for our brains and neurons, promoting connections between those different cells. “One neuron talking to another is really cool, but when neurons start talking to 400 or 4,000 other neurons, that’s when we start to see resilience in the brain,” he says. “Or having more complex or learning abilities, because that network is growing. By engaging in exercise, BDNF allows our brain to do some interesting things. That’s the basis of plasticity, the ability for your brain to change.”

Any type of movement—from a wall sit to a plank, or even a short walk—counts as a brain booster. Hennes says, “All we’re after is getting your body to move … nothing happens to your brain ‘til something moves. Whether you’re cracking a book open or moving a limb, it’s all about stimulation. Electricity, sensory input, that is what we’re after.”

Exercise not only protects brain health by promoting cell regeneration, it does a host of other things that link back to stronger cognitive function: it reduces inflammation, improves blood flow to the brain (and everywhere else), and lowers levels of cortisol, the stress hormone that can be a precursor to dementia and other cognitive disorders. Several studies even show that repeated movement can thicken the cerebral cortex, which is positively associated with intelligence.)

While the prospect of literally growing our brains (okay, thickening the cortex!) is electrifying, we don’t have to go hard to see results. “When it comes to your brain, the way you know you’ve pushed too far is like when your muscles get sore from working out too much, needing that extra three days to recover,” Hennes says. “You’ll feel tired or a little more irritable, signs that your brain got overworked.” To sum it all up: stay active, dust off those puzzles you used in the early pandemic days, and stay connected with your loved ones. There’s plenty of evidence out there that suggests social interaction is associated with slower rates of cognitive decline.