The Best Sedentary Activity For Your Memory

Could your favorite evening habit be quietly altering your brain’s future? While many of us equate all sitting with mental stagnation, new research flips that assumption on its head. It turns out that the way you spend your downtime—whether you’re scrolling, watching, or reading—could be the difference between preserving brain health and increasing your risk of dementia. What if staying mentally sharp was less about moving more and more about thinking while you sit?

Key Takeaways

• Not all sedentary activities affect the brain equally. Passive behaviors like TV watching are linked to a higher risk of dementia, while cognitively engaging tasks like computer use or reading may lower that risk.

• Cognitively active leisure matters – Activities that stimulate mental effort, even while sitting, can counteract some of the negative effects of sedentary time on the brain.

• Physical activity is still vital – While active sitting helps, it doesn’t replace the need for physical movement, which remains a proven protective factor against dementia.

Watching TV Might Shrink Your Brain Power

We’ve long known that endless time spent watching mindless television is not exactly a recipe for good brain health.¹

Now a new study underscores this notion, adding a caveat that what we do while we sit matters.² In fact, researchers say that, when it comes to our brain, certain sedentary activities are better than others. Here’s the story…

In the latest study, researchers found that older adults who curl up with a laptop have a lower risk of dementia than those who opt for countless hours of Netflix bingeing.

The observational study was based on data from 145,000-plus participants aged 60 and older in the U.K. Biobank. Each of these participants had a diagnosis of dementia at the start of the study.

During their study researchers explored two types of sedentary behavior: leisure-time computer use, and TV watching.

Interestingly, the researchers found that it wasn’t the time sitting, per se, but the type of sedentary activity conducted during leisure time that impacts dementia risk.

While this study doesn’t give you a free pass to be a couch potato, it does offer some interesting results.

All Sitting Is Not Created Equal

Researchers found that when it comes to reducing dementia risk, it’s all about shifting from passive to active sedentary behaviors.

Confused by that statement? I was too.

David Raichlen, the study's lead author and professor of biological sciences and anthropology at the University of Southern California, helped clear it up.

"We know from past studies that watching TV involves low levels of muscle activity and energy use compared with using a computer or reading," he remarks.

“And while research has shown that uninterrupted sitting for long periods is linked with reduced blood flow in the brain, the relatively greater intellectual stimulation that occurs during computer use may counteract the adverse effects of sitting."

Which Activities Are Cognitively Active?

The study shows that you can get brainy benefits by reducing the hours spent in “cognitively passive” sedentary behaviors – such as TV watching – and bumping up the time spent in “cognitively active” sedentary behaviors – such as playing a board game, reading, or browsing the internet.

Moreover, you can enjoy these same brain benefits even if you’re already physically active.

According to Prof. Raichlen, because the study is observational, the researchers can’t determine causality. However, the author believes the study forms a strong foundation for future interventions to determine the best ways to alter sedentary behavior to improve brain health and reduce dementia risk.

Plenty of research has focused on the link between brain health and physical activity. This research charts new territory as it examines whether all inactivity is created equal.

"We found that sedentary behaviors were associated with dementia risk, but surprisingly, what we do when we're sedentary impacts the direction of that risk," Prof. Raichlen said.

The Takeaway

This study is interesting, but I’m concerned that folks will take it as a hall pass for sedentary behaviors and staring at a screen for hours on end. Increasing daily activity has been proven to protect against dementia.³ Conversely, inactivity can negate the protective effects of a healthy set of genes.

We all need some sedentary leisure time; just try to avoid too much of it. Recruit some friends to play card or board games, which have been found to support brain health in older adults.⁴

Not a game fan? Try taking up a new hobby like knitting, which involves problem-solving skills.

And whether you’re glued to the TV or playing a video game, remember to get up and walk around frequently. Those minutes of inactivity and activity add up!

Summary

A large observational study of over 145,000 older adults in the U.K. found that the type of sedentary behavior, not just the amount, matters when it comes to dementia risk. Those who spent more leisure time using a computer had a lower risk of developing dementia than those who watched TV for long periods. The key difference lies in cognitive engagement: mentally stimulating activities may counterbalance the brain’s reduced blood flow during sedentary periods. While these findings are observational, they suggest that choosing active over passive forms of sitting, like reading, online learning, or puzzle-solving, could be an effective way to support brain health in aging populations.

Frequently Asked Questions

Does watching TV increase the risk of dementia?

Yes, prolonged TV watching is considered a passive sedentary activity and has been associated with a higher dementia risk.

Is using a computer better for brain health than watching TV?

According to the study, computer use involves more cognitive engagement, which may help lower dementia risk compared to passive TV viewing.

What are examples of cognitively active sedentary behaviors?

Reading, doing puzzles, using a computer, playing board games, or engaging in mentally challenging hobbies like knitting or writing.

Can physical activity still reduce dementia risk?

Absolutely. Regular physical movement remains a powerful way to protect brain health and complements cognitive activity during sedentary periods.

Should I stop watching TV altogether?

Not necessarily—but it’s wise to limit passive screen time and balance it with more mentally stimulating and physically active routines.