Exercise Is Good For The Aging Brain

In this study that included brain scans, working memory tests, and physical activity older participants were found to experience the same cognitive benefits and improved memory from a single exercise session as they did from longer regular exercise. 

"One implication of this study is you could think of the benefits day by day," says Michelle Voss. "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.' 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 at it day by day to gain those benefits."

In the past, exercise has been shown to confer a mental boost with varying results such as one may experience improved cognition, while another may have improved memory, and another person may experience very little to no gain. 

The researchers wanted to examine how a single session of exercise may affect older people. 34 adults between the ages of 60-80 were involved in this study who were healthy but not active on a regular basis. Each subject rode stationary bikes for 20 minutes on 2 separate occasions with light resistance and then with more strenuous resistance; each subject underwent a brain scan and completed memory tests before and after each session.

Bursts of brain activity in regions known to be involved in the collection and sharing of memories were examined in participant brain scans. During working memory tests subjects looked at a set of 8 young faces that rotated every 3 seconds on a computer screen, and had to decide when a face previously viewed 2 images ago matched the one currently being viewed. 

After one session some individuals were found to have increased connectivity between the medial temporal and the parietal cortex and prefrontal cortex; the same subjects also performed better during memory testing, while some subjects showed little to no gain. These cognition and memory boosts from a single session only lasted a short time for those with gains.

"The benefits can be there a lot more quickly than people think," Voss says. "The hope is that a lot of people will then keep it up because those benefits to the brain are temporary. Understanding exactly how long the benefits last after a single session, and why some benefit more than others, are exciting directions for future research."

Additionally subjects also rode stationary bikes 3 times a week for 50 minutes for 3 months; one group with moderate intensity pedaling, and another group with a lighter workout in which the pedals moved for them; those in the moderate and light intensity groups displayed mental benefits based on brain scans and working memory testing before and after the study, but gains were no greater than those from when the had a single session. 

"The result that a single session of aerobic exercise mimics the effects of 12 weeks of training on performance has important implications both practically and theoretically," the authors write.

The study was limited by a small pool with a population excluding anyone with chronic health conditions or those taking beta-blockers. To address these limitations the participant pool has been expanded in a current 5 year study to follow up and confirm initial findings and investigate more on how exercise may alter older brains.