Most of know that exercise is good for the brain, but how frequently do you have to exercise to benefit your memory—and how long do the effects last?
Researchers from the University of Iowa wanted to know the answers to these questions, so they created a study to better understand how exercise can benefit the cognitive abilities of older people.
The instant benefits of exercise
For the first part of the study, the scientists instructed 34 older participants (ages 60-80) to use a stationary bike for two separate sessions. Overall, the participants were healthy but didn’t exercise on a regular basis.
For the first session on the stationary bike, the cycling was light. But the second session required a more strenuous pedaling for 20 minutes.
All the participants took memory tests and underwent MRIs before and after each session so the researchers could monitor their brain activity in regions associated with working memory.
Some of the participants showed increased brain connectivity in the regions connected to memory. They also did better on working memory tests, but the benefits only lasted for a short time.
Comparing the results to 12 weeks of exercise
Next, the participants followed a 12-week aerobic training program that involved riding a stationary bike for 50 minutes, three times a week.
Half the group was told to pedal lightly (and the pedals rotated on their own automatically) and the other half was told to pedal moderately.
Again, both groups took memory tests and underwent MRI scans.
Although both groups in the 12-week study improved their brain connectivity and performed better on the memory test, there was no difference in the benefits compared to the group that only exercised twice.
“In terms of behavioral change and cognitive benefits from physical activity, you can say, ‘I’m just going to be active today. I’ll get a benefit,’” explains lead researcher Michelle Voss, Ph.D. “So, you don’t need to think of it like you’re going to train for a marathon to get some sort of optimal peak of performance. You just could work on it day by day to gain those benefits.”
