For people age 55 and older, the benefits of exercise — not only physical, but cognitive — are clear. Numerous studies have documented the benefits of physical fitness in reducing the risk of dementia, heart disease and mental health issues, among other conditions.
But what about exercise's mental impact on younger adults?
A new study revealed that daily aerobic exercise significantly improves cognition and brain health in people as young as 20 years old.
The study’s senior author, Dr. Yaakov Stern, said that to the extent of his knowledge, the study is the first to show cognitive benefits of aerobic exercise in people under age 55.
“It’s not just older people who benefit, it’s people as young as age 20 who are benefiting. The evidence is there,” said Stern, a Columbia University professor of neuropsychology.
Improved executive functioning
The study, published in the journal Neurology, followed a group of 132 people, aged 20 to 67, who disclosed they did not exercise regularly, if at all. (It should be noted 70 percent of the group was female, an unintentional result that was based on who completed the trial.)
The group was split into two groups, one that went to the gym and did aerobic exercise (like jogging on the treadmill, cycling or doing the elliptical) for approximately one hour, four times each week. The other group went to the gym and did stretching and toning exercises for the same duration.
The researchers wanted both groups to go to the gym to make sure the simple act of going to the gym and any socializing that happens there weren’t factors that contributed to the difference in results.
After 24 weeks, the group that did aerobic exercise performed significantly better on tests of executive function than the group that simply did stretching and toning.
Examples of executive functions include a the ability to solve problems, to unconsciously shift attention between tasks, to adapt mentally to new or different situations and to plan things. Executive functions, as you can deduce, are crucial to living a quality life.
The evidence is there.
"I think the takeaway is people should really work to build some form of aerobic exercise into their daily routines. There’s more and more evidence that it’s good for all components for health, so here’s even more evidence that it’s good for your brain as well, it’s good for cognitive function," said Stern, who also leads Columbia Cognitive Neuroscience Division.
The research should not discourage people from stretching and toning, as those exercises are known to help in a number of ways, including building strength, preventing injury and reducing stress. Though, the results point to the real benefits of aerobic exercise in the brain.
Improved brain health
The study also reported another impressive finding: Those who did aerobic exercise were actually able to reverse a common effect of aging, the thinning of the frontal cortex, which signals improved brain health.
“We gave people MRI brain scans before and then at the end, and we actually saw the thickness of the cortex, the outer layer of the brain in the frontal area, increase with exercise,” Stern said.
“So it seems that we’re not only seeing a cognitive benefit, the brain itself was responding as a function of exercise. And that wasn’t just for older people,” he added.
But the older the participants were, the more improvements they saw.
"I think the most surprising was the fact that the improvement in cognition differed as a function of age. From year to year, the older you were, the more you improved,” Stern said.
He said he believes this is because older people were able to reverse the effects aging has on cognition and brain health.
Stern admitted that he was “never an exerciser” until the research became more and more clear.
“It’s just convinced me that you really have to try to exercise.”