A few thousand daily steps could help keep Alzheimer’s and memory loss at bay for years. Credit: Shutterstock

A new study found that walking just a few thousand steps daily can significantly delay Alzheimer’s symptoms.

Participants who were more active showed slower accumulation of harmful tau proteins and preserved cognitive function for years longer. Researchers believe these findings highlight how small lifestyle changes can help protect the brain, especially in those at risk for Alzheimer’s.

Small Steps, Big Impact: Walking to Slow Alzheimer’s

Adding even a modest number of steps to your daily routine could make a meaningful difference in slowing the progression of Alzheimer’s disease for those at higher risk, according to new research. In a study published in Nature Medicine, scientists from Mass General Brigham discovered that older adults who were more physically active showed slower cognitive decline, particularly among those with elevated levels of amyloid-beta, a protein linked to Alzheimer’s.

People who walked 3,000 to 5,000 steps per day experienced an average three-year delay in cognitive decline, while those who walked 5,000 to 7,500 steps per day saw an average delay of about seven years. By contrast, individuals with sedentary lifestyles showed a faster buildup of tau proteins in the brain, which correlated with steeper declines in memory, thinking, and daily functioning.

Why Some People Resist Alzheimer’s Longer

“This sheds light on why some people who appear to be on an Alzheimer’s disease trajectory don’t decline as quickly as others,” said senior author Jasmeer Chhatwal, MD, PhD, of the Mass General Brigham Department of Neurology. “Lifestyle factors appear to impact the earliest stages of Alzheimer’s disease, suggesting that lifestyle changes may slow the emergence of cognitive symptoms if we act early.”

To reach these conclusions, researchers analyzed data from 296 participants aged 50 to 90 years old enrolled in the Harvard Aging Brain Study. None of the participants showed signs of cognitive impairment at the study’s start. Their physical activity was tracked using waistband pedometers, while PET brain scans measured amyloid-beta plaques and tau tangles. Participants underwent annual cognitive testing over a period ranging from two to 14 years (average = 9.3 years), and a subset received additional PET scans to monitor tau changes over time.

The Power of Movement Against Tau Buildup

Participants with higher step counts and elevated amyloid-beta levels experienced slower cognitive decline and less tau buildup. Statistical analyses suggested that the cognitive benefits of physical activity were primarily due to reduced tau accumulation. In contrast, individuals with low amyloid-beta levels showed minimal cognitive decline or tau buildup over time, regardless of their activity levels.

“We are thrilled that data from the Harvard Aging Brain Study has helped the field better understand the importance of physical activity for maintaining brain health,” said co-author Reisa Sperling, MD, a neurologist in the Mass General Brigham Department of Neurology and co-principal investigator of the Harvard Aging Brain Study. “These findings show us that it’s possible to build cognitive resilience and resistance to tau pathology in the setting of preclinical Alzheimer’s disease. This is particularly encouraging for our quest to ultimately prevent Alzheimer’s disease dementia, as well as to decrease dementia due to multiple contributing factors.”

Unraveling How Exercise Protects the Brain

The research team plans to further explore which aspects of physical activity are most effective, such as intensity, consistency, and long-term patterns. They also aim to uncover the biological mechanisms that connect physical activity, tau buildup, and cognitive health. These findings could help shape future clinical trials testing whether exercise-based interventions can slow cognitive decline in older adults who are at greater risk for Alzheimer’s disease.

“We want to empower people to protect their brain and cognitive health by keeping physically active,” said first-author Wai-Ying Wendy Yau, MD, a cognitive neurologist in the Mass General Brigham Department of Neurology. “Every step counts — and even small increases in daily activities can build over time to create sustained changes in habit and health.”

Reference: “Physical activity as a modifiable risk factor in preclinical Alzheimer’s disease” by Wai-Ying Wendy Yau, Dylan R. Kirn, Jennifer S. Rabin, Michael J. Properzi, Aaron P. Schultz, Zahra Shirzadi, Kailee Palmgren, Paola Matos, Courtney Maa, Jeremy J. Pruzin, Stephanie A. Schultz, Rachel F. Buckley, Dorene M. Rentz, Keith A. Johnson, Reisa A. Sperling and Jasmeer P. Chhatwal, 3 November 2025, Nature Medicine. DOI: 10.1038/s41591-025-03955-6

In addition to Yau, Chhatwal, and Sperling, Mass General Brigham authors include Dylan R. Kirn, Michael J. Properzi, Aaron P. Schultz, Zahra Shirzadi, Kailee Palmgren, Paola Matos, Courtney Maa, Stephanie A. Schultz, Rachel F. Buckley, Dorene M. Rentz, and Keith A. Johnson. Additional authors include Jennifer S. Rabin, Jeremy J. Pruzin.

This study was funded by the National Institutes of Health (K23 AG084868, K01 AG084816, P01 AG036694, K24 AG035007, R01 AG062667, R01 AG071865, P41EB015896, S10RR021110, S10RR023401, S10RR023043), the Doris Duke Charitable Foundation Clinical Scientist Development Award, and the Massachusetts Life Sciences Center.

Never miss a breakthrough: Join the SciTechDaily newsletter. Follow us on Google, Discover, and News.