A study from Baylor College of Medicine in Houston has compared up to 14 years of Fitbit step counts with scores on thinking tests, and found that people who stayed active and walked more each day tended to do better on tests of attention and decision making1. The researchers also found that keeping blood pressure lower went along with better scores1. The findings appear in the journal Scientific Reports1.
The link was real in the data but small, and the authors say they could not show that walking caused the better results1.
What the study found
The team looked at Fitbit data from 3,093 people aged 18 to 93 who take part in the All of Us program, covering the years 2009 to 20231. Besides daily step counts, the researchers looked at blood pressure records and gave participants a set of thinking tests1.
People who had gradually raised their daily step count, by an estimated 1,000 steps, scored better than less active peers1. The difference showed up mainly on tests of attention and self-control1.
Blood pressure pointed the other way. People with higher blood pressure tended to score lower on tests of impulsivity and self-control1. Each 1-point rise in systolic blood pressure (the top number in a reading, measured in millimeters of mercury) went with poorer scores on one of those tests1. People who were more active also tended to have lower systolic blood pressure, and each of the two measures was linked on its own to better scores on that self-control test1.
How the brain was measured
The thinking tests were not repeated over the years. Each participant took them once, at the end of the study period in 20231. There were four:
- the flanker task, which checks how well a person can focus on one thing and ignore distractions1;
- the delay discounting task, which measures impulsivity and self-control, for example whether someone prefers a smaller reward now over a larger one later1;
- a continuous performance task, which tests visual attention over time1;
- an emotion recognition task, which checks how well people identify basic emotions in faces1.
Most participants were 60 or older (57%), women (68%), white (75%), born in the United States (92%) and had health insurance (98%)1. That mix matters, because results from a group like this may not carry over to younger people, men, or people with less access to health care.
What it does not show
The researchers themselves flag two limits. The effect sizes, meaning how big the differences in scores were, were small1. And the design could not establish cause and effect: it cannot say whether more walking and better blood pressure control were directly responsible for the better test scores1.
Because the tests were given only once, the study measures where people stood in 2023, not how much their thinking changed over 14 years. It also cannot rule out that something else explains both habits and test results.
Experts commenting on similar step studies raise a related problem. Nikhil Satchidanand, a research assistant professor of medicine at the University at Buffalo, pointed out that early brain changes linked to Alzheimer’s could themselves lead people to move less, even before symptoms are noticeable2. He also noted that step counts reveal only one part of physical activity:
They don’t tell us much about walking intensity, cardiovascular fitness, strength training, or other forms of movement that may also influence brain health
He made those comments about a different study, but the same limits apply to any research built on step counts alone2.
Why walking might matter for the brain
The study did not test how activity might affect the brain. Shannel Elhelou, a neuropsychologist who founded Brain Centric Neuropsychology in Westlake Village, California, and was not involved in the work, offered possible explanations to Medical News Today1:
Sustained physical activity likely supports brain health through several overlapping pathways
She said exercise helps maintain heart health and manage conditions such as high blood pressure and diabetes, which can affect the brain’s blood vessels1. She added that exercise may support the brain’s ability to adapt and strengthen connections through growth factors such as BDNF (brain-derived neurotrophic factor), though the exact mechanisms are still being studied1. Activity can also improve mood and sleep, which matter for everyday thinking, she said1. These are explanations offered by an outside expert, not findings of the Baylor study.
How it fits with other step studies
The Baylor work joins several observational studies that tie more movement to healthier aging brains. None of them can prove cause on their own, and they measured different things.
- Harvard Aging Brain Study. Researchers followed 296 people aged 50 to 90 who had no signs of cognitive decline at the start2. Participants wore waistband pedometers, had brain scans for amyloid and tau (two proteins tied to Alzheimer’s), and were tested again about 9.3 years later2. People at high risk of Alzheimer’s who walked 3,000 to 5,000 steps a day had about a three-year delay in cognitive decline, and those walking 5,000 to 7,500 steps saw about a seven-year delay, compared with more sedentary people2. That study was published in Nature Medicine the year before2.
- Women’s Health Initiative. A University of California San Diego team studied 1,277 women aged 65 and over who wore activity trackers for up to a week3. Each extra 1,865 daily steps was linked to a 33% lower risk of mild cognitive impairment or dementia3. The women averaged 3,216 steps a day3.
- Barcelona midlife study. A team followed 337 middle-aged adults, most with a parent who had Alzheimer’s, for about four years4. Those who became more active showed lower levels of amyloid in brain scans than those who became less active, and people who stayed sedentary showed thinning in brain areas affected early in the disease4. Activity in that study was self-reported4.
These studies have fed a public debate over whether the popular 10,000-step goal is needed for brain benefits2. The Baylor study, by its reported findings, linked an increase of about 1,000 steps a day to better scores rather than testing any fixed target1. Satchidanand cautioned that “there’s nothing magical” about any single number, describing the link between activity and health as a continuum2.
Who is behind it and what to watch next
The work comes from researchers at Baylor College of Medicine and uses data from the All of Us program1. The sources reviewed for this article do not describe the study’s funding or any ties to Fitbit.
The main open question is cause and effect. Studies that test cognition repeatedly over time, rather than once at the end, would show whether people who walk more actually decline more slowly. Trials that ask people to raise their step counts and then measure thinking would go further still. Until then, findings like these show that walking, blood pressure and attention scores travel together in large groups of people, with small differences between them.
