A randomized clinical trial suggests that a year of guideline-level aerobic exercise was associated with small but measurable reductions in an MRI-based estimate of “brain age,” leaving participants’ brains looking close to one year younger than those of a usual-care control group.
New research from the AdventHealth Research Institute suggests that consistent aerobic exercise may help keep the brain biologically “younger,” as measured by an MRI-based biomarker.
Published in the Journal of Sport and Health Science, the randomized trial enrolled 130 healthy adults ages 26 to 58 and assigned them either to a moderate-to-vigorous aerobic exercise program or to a usual-care control group.
Participants in the exercise group completed two supervised 60-minute sessions each week in a laboratory and added home-based exercise to reach roughly 150 minutes of aerobic activity per week—an amount that matches American College of Sports Medicine physical-activity guidelines. Brain structure was measured by MRI and fitness was assessed using peak oxygen uptake (VO2peak) at the start of the study and again 12 months later.
Researchers estimated “brain age” using a measure known as brain-predicted age difference, or brain-PAD, which compares how old a brain appears on MRI with a participant’s chronological age. Prior research has linked higher brain-PAD values to poorer physical and cognitive performance and a higher risk of death.
After 12 months, the exercise group’s brain-PAD fell by about 0.6 years on average, while the control group’s brain-PAD rose by about 0.35 years; the change in the control group was not statistically significant. The net difference between groups amounted to a gap close to one year in favor of the exercise group.
“We found that a simple, guideline-based exercise program can make the brain look measurably younger over just 12 months,” said lead author Dr. Lu Wan, a data scientist at the AdventHealth Research Institute. Senior author Dr. Kirk I. Erickson, a neuroscientist and director at AdventHealth Research Institute who is also affiliated with the University of Pittsburgh, said prior studies suggest each additional “year” of brain age is associated with meaningful differences in later-life health.
To explore why exercise might affect brain-PAD, the researchers examined potential pathways including changes in fitness, body composition, blood pressure and levels of brain-derived neurotrophic factor (BDNF), a protein involved in brain plasticity. While fitness improved in the exercise group, none of those factors statistically explained the brain-PAD changes observed in the trial, leading the authors to suggest additional mechanisms may be involved.
The researchers emphasized that the observed changes were modest and noted limitations, including the study’s relatively small sample size and the characteristics of the volunteer group. They said larger studies with longer follow-up are needed to determine whether reductions in brain-PAD translate into lower risks of conditions such as dementia or stroke.
The study was funded by the National Institutes of Health and the National Heart, Lung, and Blood Institute.
