A new study suggests long-term sedentary behavior is linked to brain health…and it appears exercise can’t undo its damaging effects.
Research: If You Sit For This Long Daily, Your Brain Might Be Shrinking
Published on Jun. 18, 2025
We might list hobbies like hiking or surfing in our dating profiles, but if we’re honest, most of our favorite things to do involve sitting. Whether we’re binging the latest Netflix hit, playing video games, or reading a new book, chances are we’re parked on the couch.
And if you work a desk job, you’re probably sitting most of your waking hours.
But too much sitting is bad for our health. According to the Mayo Clinic, extended sitting has been linked to obesity, high blood pressure, high blood sugar, and high cholesterol. Now new research suggests that sitting for too long could affect the size of your brain, too.
The medical journal Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association published a study from a research team associated with Tennessee’s Vanderbilt University Medical Center about a potential connection between sedentary behavior and the risk for Alzheimer’s disease.
In this cohort study, researchers selected 404 participants who were at least 50 years old. Most participants were not cognitively impaired when the study began, but a third were APOE-ε4 positive, meaning they had at least one copy of a gene that raises their risk of developing Alzheimer’s disease, explains the Cleveland Clinic.
Reviewing the data collected, the research team noted that most patients (87%) performed at least 150 minutes of moderate-to-vigorous physical activity each week. This satisfies the recommended time presented in the Physical Activity Guidelines for Americans that the U.S. Centers for Disease Control and Prevention promotes.
How much a person exercises each day can vary, so long as the total weekly number is met. This is presumably why the study’s results indicated that participants spent an average of 61 minutes each day doing moderate-to-vigorous physical activity.
The study does not detail how it defines moderate-to-vigorous activity, but health experts say, “Moderate-intensity aerobic physical activity means you’re working hard enough to breathe harder, raise your heart rate, and break a sweat.” Exercises may include brisk walking, riding a bike, and even pushing a lawn mower.
“Vigorous-intensity aerobic activity,” on the other hand, is described as when a person “won’t be able to say more than a few words without pausing for a breath.” This could include exercises like jogging, running, swimming laps, and riding a bike on hills.
So, in contrast, how long did the participants spend displaying sedentary behavior? Results indicated that they spent an average of 13 hours (807 minutes) sitting each day.
This information and the data gathered from brain scans and cognitive assessments before and after a seven-year follow-up period suggested that greater sedentary behavior was linked to “cortical thinning” in areas of the brain associated with Alzheimer’s disease, as well as a decline in episodic memory.
Further, participants with the APOE-ε4 gene experienced a loss of gray matter in the brain’s frontal and parietal lobes, which researchers theorized made memory and recall tasks more difficult. Additional exercise did not appear to mitigate this cognitive decline.
In a press release published by Vanderbilt University Medical Center News, the study’s lead author, Marissa Gogniat, PhD, cautioned, “Reducing your risk for Alzheimer’s disease is not just about working out once a day.”
She added, “Minimizing the time spent sitting, even if you do exercise daily, reduces the likelihood of developing Alzheimer’s disease.”
Though further research is needed for more reliable data, researchers concluded, “From a personalized medicine approach, healthcare professionals might consider assessing not only a patient’s exercise regimen but also the amount of time they are sedentary throughout the day, recommending a reduction in such sedentary behavior in addition to increasing daily physical activity.”
So, even though caring for your brain requires more than just being active, it might not be a bad idea to save up for a standing desk.
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