A new study, reported in the journal Neuroscience, has shown that regular aerobic exercise improves blood flow to the brain and speeds the learning process.
The study led by researchers from the University of Pittsburgh School of Medicine is the first to examine these relationships in non-human primates.
While there is ample evidence of the beneficial effects of exercise on cognition in other animal models, such as the rat, it has been unclear whether the same holds true for people, said senior author Dr Judy Cameron.
Testing the hypothesis in monkeys provides information that is more comparable to human physiology.
“We found that monkeys who exercised regularly at an intensity that would improve fitness in middle-aged people learned to do tests of cognitive function faster and had greater blood volume in the brain’s motor cortex than their sedentary counterparts,” Dr. Cameron said. “This suggests people who exercise are getting similar benefits.”
To reach the conclusion, researchers trained adult female cynomolgus monkeys to run on a human-sized treadmill at 80 percent of their individual maximal aerobic capacity for one hour each day, five days per week, for five months.
Another group of monkeys remained sedentary, meaning they sat on the immobile treadmill, for a comparable time. Half of the runners went through a three-month sedentary period after the exercise period.
In all groups, half of the monkeys were middle aged (10 to 12 years old) and the others were more mature (15 to 17 years old). Initially, the middle-aged monkeys were in better shape than their older counterparts, but with exercise, all the runners became more fit. (It’s never too late to get fit!!)
During the fifth week of exercise training, standardized cognitive testing was initiated and then performed five days per week until week 24.
“Monkeys that exercised learned to do the cognitive tasks twice as quickly as control animals,” Dr. Cameron said. “They were also more engaged in the tasks and made more attempts to get the rewards, even though they made more mistakes.”
She noted that later in the testing period, learning rate and performance was similar among the groups, which could mean that practice at the task will eventually overshadow the impact of exercise on cognitive function.
When the researchers examined tissue samples from the brain’s motor cortex, they found that mature monkeys that ran had greater vascular volume than middle-aged runners or sedentary animals. However, those blood flow changes reversed in monkeys that were sedentary after exercising for five months.
These findings indicate that aerobic exercise at the recommended levels can have meaningful, beneficial effects on the brain.
It also shows that the benefits of exercise only last while the exercise is continued. After five months the benefits were lost.
So once you get fit, do enough to maintain your fitness.
Fortunately, it takes less exercise to stay fit than it does to get fit.
