Just a few months of aerobic exercise can help middle-aged and older adults — even former couch potatoes — improve their memory and thinking skills, according to a Canadian study published recently in the journal Neurology.
The study also found that aerobic exercise improves blood flow to the brain, particularly to areas associated with mental agility and memory.
These findings may not be surprising, but they are encouraging, for they suggest that it may never be too late to start exercising — for your brain as well as for your body.
“As we all find out eventually, we lose a bit mentally and physically as we age. But even if you start an exercise program later in life, the benefit to your brain may be immense,” says Marc Poulin, the study’s senior author and a neuroscientist at the University of Calgary, in a released statement.
How the study was done
For the study, Poulin and his co-authors recruited 206 middle-aged and older adults (ages 50 to 83) from the Calgary metropolitan area. All were in general good health, with no cognitive problems or uncontrolled cardiovascular illnesses. They were also relatively inactive, spending no more than two hours a week doing any kind of moderate-intensity exercise.
The participants were instructed to follow an aerobic exercise program for six months. It involved supervised workouts three days a week. They were also asked to work out on their own once a week. In addition to the aerobics, each session included a five-minute warm-up and a five-minute cool-down (with stretching). Over the course of the six months, the length of the workouts increased from an average of 20 minutes to at least 40 minutes.
The participants were given a series of tests at the start of the study that assessed their cognitive abilities, including executive function (skills that include working memory, planning, problem-solving and self-control) and verbal memory (the ability to retrieve verbal information stored in short-term memory). They also underwent a VO2 max test on a treadmill to determine their cardiovascular fitness and an ultrasound test to measure blood flow in their brain. The treadmill test was repeated halfway through the study, and all the tests were repeated at the end.
After the six months of regular aerobic activity, marked improvements were observed not only in the participants’ cardiovascular health, but also in their cognitive abilities. Their scores on the tests that measured executive function had improved by an average of 5.7 percent, for example, while their scores for verbal fluency had increased by 2.4 percent.
In addition, the ultrasound tests showed that the participants’ average peak blood flow to the brain had increased by 2.8 percent.
Those increases may seem small, but they’re significant, says Poulin.
“[The] change in verbal fluency is what you’d expect to see in someone five years younger,” he explains.
Limitations and implications
The study comes with several important caveats. The participants were white, well-educated and generally healthy Canadians. The findings may not be generalizable to broader, more diverse populations.
In addition, the study did not include a control group of participants — ones not assigned to an exercise regime. This lack of a control group “does not allow us to exclude the possibility that other factors (i.e., social or cognitive stimulation from the exercise intervention) may have played a role in the observed cognitive improvements,” the researchers point out.
Still, the study’s findings are supported by previous research, including a recent study that found people who improved their cardiorespiratory fitness over a two-year period tended to show improvements in their brain’s executive function and processing speed.
“Our study showed that six months’ worth of vigorous exercise may pump blood to regions of the brain that specifically improve your verbal skills as well as memory and mental sharpness,” says Poulin. “At a time when these results would be expected to be decreasing due to normal aging, to have these types of increases is exciting.”
FMI: You’ll find an abstract of the study on Neurology’s website, although the full study is behind a paywall.