Exercise may help aging brains perform better

Regular aerobic exercise may do more than strengthen the heart — it could also help aging brains stay nimble, according to new research from NYU Langone Health. In a study of mice roughly equivalent in age to humans in their 50s, scientists found that running boosted levels of dopamine, a key brain chemical tied to smooth movement, motivation, and memory.

The findings challenge the notion that the brain’s ability to respond to exercise fades with age. In fact, the researchers found that middle-aged mice experienced the same — and in some cases even greater — increases in dopamine release as much younger animals.

“Our findings make clear that the impact of exercise on brain health and mobility is not exclusive to the young,” said senior author Margaret Rice, PhD, a professor of neurosurgery and neuroscience at NYU Grossman School of Medicine.

Better coordination, not stronger muscles

In the study, about two dozen mice were given access for a month to either a freely spinning exercise wheel or one that was locked. Afterward, researchers tested the animals’ movement in tasks that required balance, coordination, and speed — such as climbing down a pole and navigating an open arena.

The results were striking. Middle-aged mice that exercised moved more quickly and with greater agility than sedentary mice of the same age. Yet their grip strength did not improve, suggesting the benefits came from better coordination rather than increased muscle power.

“This tells us the brain is playing a major role,” Rice said. “Exercise appears to fine-tune how movements are controlled, not just how strong the body is.”

Dopamine levels jump by 50%

When the researchers examined brain tissue from the mice, they found that those in the exercise group had about 50% higher dopamine release than their inactive counterparts. The measurements were taken from the striatum, a brain region essential for movement and motivation.

Interestingly, female mice ran about twice as much as males but showed similar improvements in dopamine release and motor performance. According to the researchers, this suggests there may be a threshold level of exercise needed to gain brain benefits — once reached, doing more may not add further gains.

Implications for Parkinson’s disease

The study, published in the journal NPJ Parkinson’s Disease, may offer clues for treating Parkinson’s disease, a condition marked by the gradual loss of dopamine-producing brain cells. People with Parkinson’s often experience tremors, slowed movement, and balance problems, and physical activity has long been known to ease some symptoms.

“These results provide neurochemical evidence for why exercise improves everything from memory to movement to mood,” Rice said, noting that all of these functions are affected in Parkinson’s disease.

The research team plans to next test exercise effects in mice genetically engineered to model Parkinson’s disease. Rice emphasized, however, that studies in humans will be needed before firm conclusions can be drawn.

A simple message for older adults

While the research was done in animals, the takeaway may resonate with older adults: staying physically active can benefit the brain as well as the body. Activities that raise the heart rate — such as walking briskly, swimming, cycling, or dancing — may help preserve coordination and mobility well into later life.

“As we age, we don’t lose the ability to respond to exercise,” Rice said. “By getting enough physical activity, we can still help our brains support faster, easier movement.”