Being Sedentary for 10+ Hours a Day Is Linked to Higher Dementia Risk, Study Finds

The age-old advice to stand up and walk around every 20 to 30 minutes—or at least once an hour—isn’t something to scoff at. Humans aren’t meant to sit or lie down for long, uninterrupted periods of time (except when we’re sleeping, sick, or injured, of course). And yet we do, and this prolonged inactivity can impact so many facets of our health, including cognitive health.

Sedentary Lifestyle Risks

According to the Centers for Disease Control and Prevent (CDC), more than 60 percent of U.S. adults don’t get the recommended amount of physical activity needed for optimal health—and roughly 25 percent of U.S. adults are sedentary, meaning they get no activity at all. 

Being sedentary—sitting/reclining for extended periods of time and getting insufficient physical activity daily—has been linked to various poor health outcomes, including increased risk of mortality from heart disease, diabetes, high blood pressure, and colon cancer. It also ups the chances of developing mood and mental health disorders like anxiety and depression, as well as sustaining aches, pains, and injuries from poor muscle, joint, and bone health.

Study Suggests Sedentary Behavior a Potential Risk Factor for Dementia

A 2023 study published in JAMA suggests another potential connection between being too sedentary and health—and it has to do with brain health as we age. Looking at past data from nearly 50,000 U.K. Biobank participants who were 60 and older, researchers found that “among older adults, more time spent in sedentary behaviors,” aka not moving at all, “significantly associated with higher incidence of all-cause dementia.” 

Participants, who did not have dementia at the start, wore accelerometers (devices that monitor movement) on their wrists to assess their sedentary behavior (or overall activity levels). After a 6-year follow-up period, 414 of them were diagnosed with dementia. 

Keeping in mind that the results were correlational (vs. causal), researchers noted that participants’ chances of developing dementia increased if a total of 10 hours of their day were spent sedentary—or exerting no energy or being physically active (think: sitting at a work desk or lounging on the couch). The longer the total time spent in sedentary behaviors, the higher the risk for dementia. So those who spent 15 hours of the day total being inactive were three times as likely to develop dementia compared to more active participants.

The study authors also emphasized that the number of times a participant was sedentary throughout the day wasn’t necessarily associated with a higher dementia risk—rather it is the total number of hours of inactivity that were significant.

3 Ways to Be Less Sedentary

Slotting in time for formal exercise—an hour at the gym, a weight-training session, a spin class, a jog—is always encouraged and a fantastic way to help offset all the downsides of sitting for most of the day. But what about the daily movement that doesn’t require a change into athleisure clothes or a shower afterward to rinse off sweat?

Commuting and Transportation  

Think about the way you get from A to B. Can you park a little farther from the office building to get in a few more steps? Get off the bus a stop earlier (safety permitting)? Take the stairs instead of the escalator? Bike to the store instead of driving? There’s no one-size-fits-all advice, and you can only do what you are able and willing to do. But there are countless small, creative ways to make your daily transportation methods a little more active.

Take Frequent Breaks to Interrupt Long Periods of Sitting

Take plenty of breaks throughout the day if you’re sitting at a desk for most of it. Walk to the farthest bathroom, do yoga stretches in your chair, touch your toes, grab coffee with a colleague. You are not a bad employee shirking your work responsibilities—you’re taking care of your body and brain so you can show up long-term in your best form. A 2018 study found that periodically resting during mentally demanding tasks helped decrease fatigue and cognitive overload and boost overall performance—with enhanced benefits when that break included some physical activity or relaxation exercises.

Do More Things for Yourself

Consider the modern conveniences we rely on so heavily—the apps and services we use to sidestep the hassle of actively getting things done ourselves. No doubt they make life easier in the short term, especially when we're sick, busy, injured, or otherwise having a hard time (of course, there’s no use suffering and making your life harder for no reason).

But they also make life way more sedentary. The human body was designed to move, not to have things done for it at all times. Do you get your meals, groceries, prescriptions, or online shopping delivered straight to your door? Can you mix it up every once in a while and go pick up your own food from a restaurant or supermarket? Can you get your online purchase delivered to the nearest store location and pick it up there? Can you try to build that IKEA desk instead of hiring a Task Rabbit—or rake the leaves on your lawn yourself? Can you physically get up to change the thermostat temperature instead of doing it on a phone app? Again, everyone has their own threshold for which conveniences they can and are willing to sacrifice. But if you really want to kick sedentary habits, think about the tasks and errands in your life for which you can sneak in a little more activity (there are probably tons to choose from!).