Study: Brief, brisk workout can improve cognition

Adela Talbot // Western NewsMatthew Heath, a Kinesiology professor at Western, teamed up with Ashna Samani, a former graduate student, to see if 10 minutes of exercise – half of the previously documented required duration – would be enough to provide a boost in cognitive function.

Approaching his latest study, Matthew Heath already knew aerobic exercise can be as good for the mind as for the body. What he wanted to find out was how long you need to exercise in order to reap those cognitive benefits.

There’s a well-documented link between exercise and improved executive functions such as working memory and impulse control. But, until now, the brain boost following exercise has been correlated with bursts of activity lasting 20 minutes or more, said Heath, a Kinesiology professor at Western.

He teamed up with Ashna Samani, a former graduate student, to see if 10 minutes of exercise – half the duration previously documented – would provide the same cognitive improvement.

The pair recently published a study, Executive-related oculomotor control is improved following a 10-min single-bout of aerobic exercise: Evidence from the antisaccade task, showing that 10 minutes of exercise was, in fact, sufficient to generate a cognitive boost.

“Exercise is beneficial to this thing called executive control – your ability to remember what I just said, your ability to inhibit what you don’t want to do. It’s very much high-level cognitive processing and it involves a whole bunch of networks in the brain,” Heath said.

“Meta-analyses, or systematic reviews, previously said 20 minutes of exercise was required to elicit any sort of benefit, but the previous studies that looked at that issue used very crude measures of cognitive performance. We had a more sensitive measure to detect more subtle improvements in executive function following exercise,” he added.

In Heath and Samani’s study, participants cycled for 10 minutes at a moderate to vigorous intensity of aerobic output; the pair measured executive performance before and immediately after the exercise session by examining eye movements, Heath explained.

They instructed study participants to look directly at a target in front of them, a function called a prosaccade task. We all do this about 150,000 times a day, Heath said, and it is the most well-learned task one can perform.

The challenge came from asking people to do the opposite, he said. “A target flashes on a screen and instead of looking at it, people have to look away from it. It seems really simple to do – but because we prosaccade so often and so many times a day, it’s actually cognitively very complex and involves activation of the same networks in the brain that have shown long-term benefits from long-term exercise.”

Heath and Samani used this antisaccade task to measure an individual’s eye movements and, by extension, measure the speed of cognitive function. The pair found 10 minutes of exercise significantly improved volunteers’ antisaccade performance.

The work is particularly relevant to people with early signs of Alzheimer disease, who haven’t yet been diagnosed but who have a high transition rate towards the disease.

“We’ve shown when these people participate in a 24-week exercise program, they actually have improvement to their executive control,” Heath said.

But not all of them are physically or cognitively capable of exercising for the recommended 30-60 minutes of the exercise program he added. This study shows even short exercise periods can benefit participants’ brains.

“It’s not to say we advocate people should exercise for only 10 minutes; it’s just in the cases where people can’t go for more than 10 minutes. Next, we want to be able to find out what the intensity should be, how vigorously they should be exercising and if there is an age associated with that,” he continued.

“It’s probably the case that all people need to do is go for a brisk walk and that will probably provide sufficient threshold for the benefit and we are determining whether there is an age specificity with the (exercise) intensity.”