Exercise on the Brain

Smith, who watched his own grandmother succumb to Alzheimer’s disease, has explored the link between exercise and brain health for over 20 years. His team at UMD’s Exercise for Brain Lab is now mining high-quality MRI data from hundreds of subjects to help further understand the brain’s response to exercise—and to offer diagnostic proof that movement is medicine for memory.

Below, Smith offers a peek inside the aging brain and explains why we should all be lacing up our sneakers.

What’s happening in the brain as we age?
Inflammation intensifies and challenges the neural systems and how they operate. Our metabolic health plays a role too: If the brain isn’t getting enough energy, cells begin to die off in areas like the hippocampus. Not only will you have problems recalling short-term memories, you can’t transform them into long-term memory.

How does exercise affect that process?
What we’re finding is that exercise can strengthen, even regenerate the connections between brain networks responsible for a person’s ability to think clearly and recall memories. After just one session of exercise, subjects are able to learn better, but we see improvements in many different functions. People are faster and more accurate on testing, their executive functioning is improved, and they have better memory recall.

Could your findings translate to other issues, like mental health?
Oh, of course. We find that exercise impacts areas of the brain that regulate your mood; it’s protective against depression. A study by a former doctoral student on mood after exercise found that exercise quieted a brain network that is overactivated with depression and anxiety. So that’s an area we’re also studying. It has a lot of appeal because many people struggle with mental health.

Can exercise be protective?
I think we’re a far cry from saying it’s a cure for anything, but for Alzheimer’s, it certainly can be useful as an adjunct to other treatments, and it might protect people from getting it for a certain amount of time.

Who should care about this?
We all should. After the age of 35, cognitive abilities start to decline. Exercise is a lifestyle behavior that works across age, sex and genetics. Yet it’s inaccurately prescribed; it’s not paid for by health plans or insurers as a treatment. But you can give a dose of exercise, and it has a real effect on these brain networks that could, over time as those doses are repeated, generate changes in the brain that would be good for you.