Is Running Aging Your Brain? Here’s What a New Study Says

Scientists are making progress in understanding the exact role that physical activity plays in brain health and aging.

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As a neuroscientist—and a runner—I spend a lot of time thinking about how our daily habits shape the brain. One of the most exciting tools we now have is the ability to estimate a person’s “brain age” using MRI scans. Unlike our chronological age, brain age reflects the actual health and resilience of your brain tissue.

Researchers have used brain-age models to study everything from dementia to depression. But until now, few have explored how lifestyle factors, like physical activity, affect our brain’s health.

That’s precisely why a new study published in Health Data Science caught my attention. Using accelerometers to measure movement and advanced neuroimaging, the researchers posed an interesting question: What is the relationship between physical activity and brain age?

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For runners, this question feels especially relevant. We already know running enhances cardiovascular health, boosts mood, and supports longevity. But what is its impact on the aging brain? Could the intensity or duration of your workouts influence whether your brain stays “younger” for longer?

The purpose of this study was simple, but its methods were complex. So, let’s break it all down.

Tracking Movement, Scanning Brains

For this study, the research team tapped into the UK Biobank, one of the world’s largest population-based collections of brain imaging and physical activity data. From 16,972 participants, they analyzed two key data streams: structural MRI scans and accelerometer readings. The UK Biobank is also the largest database to measure physical activity with accelerometers, making it uniquely suited to reveal how movement patterns—captured with the same type of wearable tech many runners already use—relate to brain age.

The structural MRI scans were used to identify 1,425 unique image-derived phenotypes (IDPs), or structural and functional characteristics of the brain, that can be used for comparison purposes. Researchers combined these IDPs with chronological age to generate a brain age prediction model, which then calculated the brain age gap (BAG). BAG is the participant’s estimated brain age minus their chronological brain age. If BAG is positive, then this suggests accelerated aging of the brain.

The physical activity data tracked the intensity of movement and researchers broke the accelerometer data into three categories of physical activity intensity: light-intensity physical activity, moderate-intensity physical activity, and vigorous-intensity physical activity. In runner terms, light intensity might look like walking the dog or light cross-training, the moderate activity could equate to an easy-paced run where you can hold a conversation, and the vigorous intensity would be the kind of running that spikes your heart rate–think intervals, hill sprints, or racing all-out. Researchers also tracked duration and frequency of activity.

What the Data Showed About Brain Age

The results indicated a U-shaped relationship between physical activity and brain age gap (BAG), irrespective of intensity, and showed that moderate amounts of physical activity correlated with reduced brain aging.

Low and high amounts of physical activity in terms of frequency and duration correlated with accelerated brain aging, while moderate amounts correlated with slower aging. In other words, too little movement or too much movement throughout the week was linked to older-looking brains, whereas the middle ground seemed to be the sweet spot for brain youthfulness. The intensity of the activity itself—whether light, moderate, or vigorous—did not appear to be a modifying factor.

It’s not yet clear what’s happening at the biological level to cause these results, but previous research illuminates several possibilities. Light physical activity alone may reduce blood flow to the brain, resulting in tissue being deprived of optimal nutrients. This reduced blood flow may also limit the production of brain-derived neurotrophic factor (BDNF), a protein that supports the growth and maintenance of brain cells. On the other hand, exercising too often may increase inflammation in the brain, which might accelerate aging.

These results may suggest that easy movement every day may not be enough to reap the full neurological benefits of training, and stacking too many hard workouts back-to-back could also work against brain health.

Limitations of This Study

While the results are interesting, they only suggest correlation, not causation. As the researchers highlighted, long-term studies should be conducted to better understand any causal effects between physical activity and brain aging.

Another limitation of this study is that participants averaged 62 years old and were predominantly White, which limits the generalizability of these results. Younger, more diverse, and more athletic populations—like competitive runners—might show different patterns altogether. It’s also worth noting that the accelerometer data only captured a single week of activity, which may not fully represent participants’ typical training styles or seasonal changes in volume and intensity.

Why the Study Matters

Overall, though, this study is a promising step in the study of running and brain health.. First, researchers used objective, accelerometer data versus subjective, self-report measurements. This is notable because self-reports are always subject to recall bias, which can lead to overestimating the amount or intensity of exercise performed. Or, in the case of runners, conveniently “forgetting” those extra rest days.

Second, this study promotes BAG as a potential way for researchers (and athletes) to understand how lifestyle factors, such as exercise intensity and duration, affect brain age and overall brain health—not just cardiovascular health. This and subsequent studies might eventually lead to personalized training recommendations not just for peak race performance, but also for keeping the brain sharp over the long haul.