A recent study indicates that engaging in regular aerobic exercise during midlife can make the brain functionally younger, potentially altering the trajectory of brain aging. The research involved 130 sedentary men and women, primarily in their 40s, who were divided into two groups: one that participated in a simple aerobic exercise program and a control group that remained inactive. After one year, brain scans revealed that the exercisers’ brains appeared more youthful compared to their baseline measurements, while those in the control group showed signs of slight aging.

Kirk I. Erickson, director of translational neuroscience at the AdventHealth Research Institute in Orlando and the study’s senior author, emphasized that the findings demonstrate the brain’s capacity for change and highlight exercise as a powerful tool for modifying brain health. Erickson suggested that midlife, approximately between ages 35 and 55, might be a critical period during which physical activity can significantly influence brain aging.

The concept of brain “biological age” was central to the study. This measure estimates how well a brain functions compared with others of the same chronological age, using machine learning algorithms to analyze structural brain features such as white and gray matter, blood vessels, and lesions through MRI scans. Participants who exercised not only improved their overall fitness but also showed reductions in brain age equivalent to about seven months. While modest, Erickson noted that such reductions could accumulate over time to produce more substantial benefits.

Interestingly, the study found no direct link between improved fitness markers—such as blood pressure, body weight, or cardiovascular health—and changes in brain age. This suggests that other factors, possibly inflammation, insulin sensitivity, or stress hormone levels altered by exercise, may underlie the brain’s response.

Experts not involved in the study acknowledged its importance but noted that brain age alone might not fully capture the impact of exercise on cognitive health. Jennifer Heisz, director of the NeuroFit Lab at McMaster University, pointed out that brain age estimates do not specify which brain regions have changed, nor do they indicate improvements in cognitive function or reductions in dementia risk. Erickson concurred, indicating that forthcoming research will investigate specific brain areas such as the hippocampus, memory and thinking skills, and aim to determine optimal types and amounts of exercise for reducing brain age.

This work builds on earlier findings that link aerobic exercise to increases in brain volume and neurochemical processes beneficial for brain health, predominantly studied in older adults. By focusing on midlife, the current study highlights a potentially pivotal period for interventions to maintain cognitive resilience later in life.

For now, Erickson concluded, the evidence reinforces that regular aerobic exercise remains one of the most effective non-pharmaceutical approaches to fostering brain health across the lifespan.