Everyday physical activity, like going for a short walk or playing with the kids, may provide short-term benefits for cognitive health, equivalent to reversing four years of cognitive ageing. That was a key finding for my colleagues and me in our new study, which was published in the journal Annals of Behavioral Medicine.

Prior to enrollment into a study of diet and dementia risk, we asked a diverse sample of 204 middle-aged adults to check in five times per day for a period of nine days, via a smartphone application.

Each check-in involved completing a brief survey that asked about their mood, dietary choices and whether they engaged in any physical activity in the roughly three and a half hours leading up to the survey. In addition, participants completed a few brief brain games — meaning performance-based cognitive assessments that lasted about one minute each — to assess mental speed and short-term memory.

My team found that performance on our measure of cognitive processing speed improved during check-ins when participants reported being physically active in the time leading up to the survey. While we didn’t see improvements in our measure of working memory, the time taken to complete the memory task mirrored what we saw for the measure of processing speed.

We observed these improvements in speed regardless of whether the activity was lighter intensity or moderate-to-vigourous intensity. This led us to conclude that movement, whether it took the form of intentional exercise or part of a daily routine, was the essential ingredient for achieving this benefit.

Why it matters

As a rule, we get slower, both physically and mentally, as we age. While research on exercise and living a healthy lifestyle has demonstrated the long-term cognitive and brain health benefits of remaining physically active, much of this work has focused on the moderate — to vigourous-intensity physical activity — or what most of us think of as exercise — recommended by the Physical Activity Guidelines for Americans.

Still, these guidelines and other experts recommend that adults move more and sit less. My colleagues and I are interested in understanding how moving more can improve our cognitive health or reduce our risk of dementia as we age, at what timescale these benefits show up, and what types of movement qualify.

What still isn’t known

Our study relied on participants to report whether they had been physically active during the time between each check-in. Even though participants were provided training on how to think about the intensity levels, it’s possible that each participant had a slightly different perception of their activities.

For example, a participant may not have believed their recent walk actually qualified as a moderate-intensity activity. Physical activity monitors that can dissociate time and intensity might help future research unravel these associations more clearly.

What’s next

It isn’t yet clear whether these short-term benefits accumulate over time to result in long-term improvements in brain health and dementia risk reduction. Research efforts are underway by our team to better understand these associations over broader timescales.—Borneo Bulletin

Published in Dawn, December 23rd, 2024