In news that you shouldn’t take sitting down, a recent study published in JAMA finds that people who stay seated for long hours at home and work are at much higher risk of developing dementia than those who sit less. Researchers found that the adverse effects of extended sitting can be so strong that even people who exercise regularly face higher risk if they sit for most of the day.

Andrew Budson, a professor of neurology at Boston University, said the study, which involved 48,841 women and men aged 60 or older, “supports the idea that more time spent in sedentary behaviors increases one’s risk of dementia.” It should be noted that Budson was not involved in the study. The results also emphasize how extensive the consequences of sitting can be, affecting our minds and bodies, and they hint that exercise by itself might not be enough to protect you.

The downsides of over-sitting are well-known to scientists and most of the rest of us. Past research shows that people who sit throughout the day, accumulating multiple hours of sedentary time at the office, commuting, and at home, in front of televisions and computers, are more likely to develop heart disease, obesity, diabetes and other illnesses, and die prematurely compared to people who often get up and move around.

Sitting can even undermine the exercise. According to other recent research, people who work out but then sit for the rest of the day wind up erasing some of the expected metabolic benefits of their exertions. But whether sitting likewise affects brain health hasn’t been as clear. Some studies have linked sitting and later memory problems, including Alzheimer’s disease and other forms of dementia. But they’ve primarily relied on people’s recall of how much they sit, which can be inaccurate.

So, for the new study, scientists at the University of Southern California and other universities sought objective measures of sitting and found it in the UK Biobank, an extensive repository of data about the lives, health and deaths of hundreds of thousands of British men and women. Many Biobank participants wore a sophisticated activity tracker for a week after joining the study to minutely record their movements and stillness throughout the day.

The scientists pulled records for almost 50,000 of these men and women aged 60 or older who didn’t have dementia when they joined the study. With the help of artificial intelligence algorithms that could interpret the tracker readouts, the scientists identified every minute during the day when people were moving or sedentary — meaning they were sitting or lying down but not sleeping.

The best way to reduce dementia risk is to find ways to sit less overall. People in the study who were sedentary for 9.5 hours a day had no increased risk. If your job requires a lot of desk and computer time, look for opportunities to be in motion during the day. Stroll around your office while you’re on the phone, schedule walking meetings, or pick up your lunch instead of having it delivered.