EXERCISE NECESSARY FOR BRAIN HEALTH

Accessibility statementSkip to main content Democracy Dies in Darkness paymentguy Well+Being Fitness Food Mind Body Life Newsletter Ask a Doctor Fitness Want a younger brain? Exercise in your 40s may help. Even if you’ve never worked out, starting in middle age — even with brisk walks — can have a bigger impact on your brain than you think. June 23, 2026 at 5:00 a.m. EDTToday at 5:00 a.m. EDT 7 min Summary 9 Make us preferred on Google (iStock) Column by Gretchen Reynolds Regular exercise during midlife makes brains functionally younger. That’s the bracing conclusion of a new study of 130 inactive men and women, most in their 40s. Some began a simple, aerobic exercise program. Others didn’t. Get concise answers to your questions. Try Ask The Post AI. At the end of a year, the exercisers’ brains appeared more youthful on scans than they had been at the start. The other groups’ brains looked slightly older than before. The results “are telling us that the brain is modifiable, and that exercise is a great way to modify it,” said Kirk I. Erickson, the director of translational neuroscience at the AdventHealth Research Institute in Orlando and senior author of the new study. They also indicate that midlife may be “an important inflection point” for brain health, Erickson continued. Exercise between the ages of about 35 to 55 might “change the trajectory of brain aging” for years to come. “This is important work,” said Jennifer Heisz, the director of the NeuroFit Lab at McMaster University in Ontario, Canada. She studies exercise neuroscience but was not involved with the new study. The findings raise questions, though, about which workouts might be best, how exercise actually slows or reverses brain age and whether it’s ever too late to turn back the clock on your brain. Exercise remodels brains The idea that exercise influences brain health is almost indisputable now. Decades ago, researchers first discovered that aerobic exercise, such as running, doubled or tripled the creation of new brain cells in rodents and presumably in people. Exercise also amplified the production of neurochemicals that promote new blood vessels and cellular connections throughout the brain. And in a seminal exercise neuroscience study from 2011, Erickson and his colleagues found that a year-long program of brisk walking increased the volume of the hippocampus in older volunteers. The hippocampus is an area of the brain essential to memory formation that usually shrinks with age. It grew in the older men and women who started to exercise. Much of this past research focused on older people, understandably, since they tend to be the ones whose brains and thinking falter and fade. But recently Erickson began wondering about midlife. Are our brains aging then in ways that influence our cognitive resilience or decline later? Can we change that process? Would exercise matter? Or, in simpler terms, could midlife exercise affect the biological age of people’s brains? What is biological age? Biological age refers to our bodies’ functioning, or how well it works compared to the bodies of other people who share our birth date. Your biological age can be higher or lower than your chronological age, depending on how healthy you are, and so can the biological age of each of your organs (and probably each of your cells). Your brain, for instance, is believed to have a biological age — known, mundanely, as your brain age — that can be assessed in various ways. One of the simplest is a brain scan that documents its structure, including levels of white and gray matter, lesions, blood vessels, etc. Machine learning algorithms then can compare your brain’s structure to that seen in tens of thousands of scans of other people of all ages to estimate your brain’s biological age. In studies, a low brain age, especially one lower than your actual age, is associated with better cognitive health in old age and less risk of dementia or other conditions caused by neurodegeneration. But it hasn’t been clear how fitness and exercise affect brain age, especially in midlife adults whose brains presumably are about as healthy as they’ll ever be. Most Read in Fitness Next Column Jordan D. Metzl, MD As a doctor, I tell people to do these 4 things to reduce age-related muscle loss As a doctor, I tell people to do these 4 things to reduce age-related muscl... June 15, 2026 Column Gretchen Reynolds This exercise ‘sweet spot’ is linked to greater longevity This exercise ‘sweet spot’ is linked to greater longevity June 16, 2026 Midlife fitness linked to longer, healthier lives, study finds Midlife fitness linked to longer, healthier lives, study finds May 17, 2026 4 minutes of exercise a day could help control blood sugar 4 minutes of exercise a day could help control blood sugar May 28, 2026 At 92, she’s as fit as someone half her age At 92, she’s as fit as someone half her age June 10, 2026 How exercise affects brain age So Erickson and his colleagues recruited 130 men and women, age 26 to 58, who rarely, if ever, exercised. They checked everyone’s aerobic fitness, blood pressure, body mass index and other measures of health, and scanned their brains with magnetic resonance imaging, to find their brain age. Then half of the volunteers started a supervised aerobic exercise program, showing up at a university lab to work out twice a week for about an hour, using treadmills, bicycles or other equipment. The workouts were challenging but not punishing, mostly brisk walking or jogging. People also worked out at home several times a week, until they’d completed at least 150 minutes a week of exercise. The control group continued with their normal routines. After a year, everyone returned to the lab for a second round of health tests and brain scans. As expected, the exercisers were now fitter than before and, in general, fitter than the control group. More surprising, their brains looked different than they had at the start, unlike the control groups’. They looked younger. Seven months younger On average, the exercisers had reduced their brain age by the equivalent of about seven months. That decline isn’t large, Erickson said, but “over time, the cumulative change in brain age” with exercise “could add up to quite a few years’ reduction down the road.” Meanwhile, the brains of people in the control group generally looked older (which makes sense, since a year had passed). Interestingly, the scientists found no correlation between changes in fitness, blood pressure, body weight or other health markers and changes in brain age. “This suggests something else” drove the relationship between physical activity and lower brain age, Erickson said, such as altered inflammation, insulin sensitivity or stress hormone levels after exercise. His group plans to focus on those health markers in future publications and experiments, he said. There also are questions about whether brain age is the best gauge of brain health, Heisz said. “It doesn’t tell us which specific brain regions changed, whether cognition improved, or whether dementia risk was actually reduced.” Erickson agrees and said he and his colleagues will look at individual brain regions such as the hippocampus in upcoming studies. They’ll also track the effects of brain-age changes on thinking skills and memory. And they’re hoping to assess how much and which types of exercise prompt the greatest reductions in brain age, as well as whether those reductions are similar in elderly people who start to exercise. But for now, this study is further confirmation that, “outside of pharmaceutical approaches,” Erickson said, regular exercise seems to be “the most robust” way to keep your brain youthful and strong, whatever your age. Do you have a fitness question? Email YourMove@washpost.com and we may answer your question in a future column. 6 things a neurologist does to keep his brain healthy https://www.washingtonpost.com/wellness/2026/06/23/want-younger-brain-try-brisk-walking-study-suggests/