Cardiovascular health, metabolic balance, and improved mood are well-established outcomes of regular exercise. But an expanding body of neurobiology research reveals that the most remarkable benefits may occur in the brain – where physical activity enhances neuroplasticity, promotes cellular repair, and supports cognitive longevity.
Rong Zhang, Ph.D.
That’s why every evening Rong Zhang, Ph.D., laces up his sneakers and walks along quiet neighborhood paths with his wife. It’s a ritual he follows for 45 minutes to an hour every day – and up to twice daily on weekends. For Dr. Zhang, who studies the effects of regular physical activity on the brain, aerobic exercise is part of routine upkeep for cognitive health, and he’s become a leading voice in bringing the evidence to the forefront.
“I would like people to talk about exercise like hygiene,” said Dr. Zhang, a Professor of Neurology, Biomedical Engineering, and Internal Medicine at UT Southwestern Medical Center and Director of the Cerebrovascular Lab at the Institute for Exercise and Environmental Medicine, a joint project of UT Southwestern and Texas Health Presbyterian Hospital Dallas. “We can see the results – people who engage in regular exercise for just one year improve their brain perfusion and slow down arterial aging.”
Aerobic exercise is not just something to be measured with a fitness tracker; it’s a way to care for the body’s vascular health and improve brain function. His research supports a medical observation made over 300 years ago – Thomas Sydenham’s famous dictum, “a man is as old as his arteries” – a statement that continues to hold true in modern science. Supported by the National Institutes of Health (NIH), Dr. Zhang’s work has shown that aerobic exercise reduces central arterial stiffness – a hallmark of arterial aging – and improves brain perfusion and white matter integrity.
Lessons from space
Dr. Zhang brought his engineering and physics background along with this passion for the topic to UT Southwestern after studying the effects of microgravity on the cardiovascular system as part of the NASA Neurolab’s “Decade of the Brain,” a national initiative formed in 1990 to recognize advances in understanding the basic structure and function of the brain. Dr. Zhang and his team developed new technologies to measure what happens to brain blood flow during spaceflight.
The researchers found that brain blood flow in space is maintained at a level similar to that on Earth, but when back on the ground, the opposite was observed: The effect of gravity on the cardiovascular system can lead to dysfunction of blood pressure regulation, instability of brain blood flow, and syncope, a mechanism related to falls and brain injury in older adults.
These early findings inspired Dr. Zhang to shift his focus to cerebrovascular function and the decline of brain health in older adults. Perhaps most surprising is the evidence showing that meaningful gains in cognitive and vascular health can come from remarkably modest effort – including a routine as simple as walking regularly for a year.
“We found that exercise improves the brain blood flow linked with the slowdown of arterial aging,” he said. “The bottom line: Exercise is good for brain health.”
A multidisciplinary approach is essential
Expertise in cerebrovascular function is only one part of the puzzle. Modern medicine tends to silo specialties, but not at UT Southwestern. Dr. Zhang’s research teams intentionally span many disciplines to focus on understanding the whole body and how the organs communicate to each other through blood circulation and autonomic neural activity to maintain brain health.
“We need to understand how these things integrate together,” said Dr. Zhang, who is also an Investigator at the Peter O’Donnell Jr. Brain Institute at UT Southwestern. “Each person on our team has their strengths, so we learn from each other. Taking a cross-disciplinary approach has had the most important impact on my research career.”
One example he shared is the research suggesting that treating blood pressure aggressively by following Life’s Essential 8 guidelines, key measures for improving and maintaining cardiovascular health, as defined by the American Heart Association (AHA), resulted in a reduced risk for dementia and Alzheimer’s disease. Following these findings and using cutting-edge imaging and biomarkers, Dr. Zhang is working with a multidisciplinary team to study how addressing hypertension can slow down the buildup of beta amyloid plaques in the brain, a hallmark of Alzheimer’s disease.
“We know hypertension is bad for your brain because of stroke,” he said. “But what is the optimal blood pressure level to slow neurodegenerative disease progression such as Alzheimer’s disease, and how much exercise is needed to make a difference? This is the evidence we’re trying to add to this guidance.”
Modest activity, measurable impact
Exercise is an important step in AHA’s Life’s Essential 8 guidelines for lowering blood pressure. While the effects of exercise on muscle fibers can be felt after three to six months of increased fitness, the effect on brain health is less clear. This is a question Dr. Zhang and his team are looking to answer as they study the long-term effects of exercise on neurocognitive function.
“When people think about their heart, they don’t think about their brain; and when they’re thinking about their brain, they don’t think about their heart,” he said.
His team is examining how physical and cardiovascular fitness translate into healthier neurons. Decades of cardiovascular research show that aerobic exercise benefits the heart, but its role in protecting the brain – particularly in preventing dementia – is far less understood. The focus of Dr. Zhang’s current work centers on how vascular changes drive neuronal health and how long it takes for those changes to translate into measurable cognitive improvements.
The future of cognitive health
Although today’s neuropsychological tests and imaging tools may miss the earliest changes, a growing body of evidence shows that even modest, consistent exercise measurably benefits the brain. And those gains begin early. That’s why establishing long-term habits around physical activity and cardiovascular health – well before symptoms appear – is critical.
While the finer molecular and cellular pathways are still being mapped out, one conclusion is unmistakable: Prevention works. Prioritizing exercise even at the most basic level doesn’t just strengthen the heart and body; it supports healthier brain function too. As research advances and multidisciplinary teams continue to deepen understanding, the connection between physical activity and cardiovascular and brain health becomes increasingly undeniable.