Brain health: Harvard expert says this is the best way to boost memory and thinking ability

If you have been wondering whether there's something you can do right now to protect your memory and thinking skills, a Harvard neurologist has news. The answer isn't a pill or some expensive brain-training app. It's something you can start today, and it doesn't require spending anything at all.

According to Dr. Scott McGinnis, an assistant professor of neurology at Harvard Medical School, many studies have shown that the parts of the brain controlling thinking and memory are actually larger in people who exercise regularly compared to those who don't.

Exercise changes your brain in concrete ways

The science here is pretty straightforward, though the results are remarkable. McGinnis explains that engaging in regular exercise of moderate intensity over six months or a year is linked to an increase in the volume of selected brain regions.

And then there's the indirect boost. Exercise can also improve memory and thinking indirectly by boosting your mood and sleep quality, and by reducing stress and anxiety—problems that frequently cause or contribute to cognitive decline. So exercise becomes this compound effect. You're not just changing your brain directly. You're also fixing the other stuff that damages your thinking.

Which type of exercise actually matters most

Here's where it gets tricky. Almost all the research on exercise and brain health has focused on walking. But McGinnis notes that it's likely other forms of aerobic exercise that get your heart pumping might yield similar benefits.

That said, some surprising findings have emerged. A study published in the Journal of the American Geriatrics Society found that tai chi may enhance cognitive function in older adults, especially in executive function—the mental processes that handle planning, working memory, attention, and problem solving. The reason? Tai chi requires you to learn and remember new movement patterns while staying focused. It's a different kind of brain workout than just pounding pavement.

You need to stick with it

Here's the thing McGinnis wants people to understand: this isn't a quick fix. It takes about six months to start seeing the cognitive benefits of exercise, and he recommends aiming for 150 minutes per week of moderate intensity exercise, like brisk walking.

The practical advice is solid. Start small, a few minutes a day, and then add five or ten minutes each week until you hit that 150-minute target. The key is treating exercise like a prescription you can't skip. McGinnis recommends establishing exercise as a habit, almost like taking a prescription medication, and then continuing it for life.

The bottom line: your memory and thinking skills aren't fixed. They're changeable. And the tool to change them is something you can access whenever you want to walk out the door.