Could just one exercise session be enough to boost brain function?

The researchers concluded that fatigue and a reduction in cognitive capacity may constitute the first step in burn-out

New US research has found that even a single exercise session appears to give the brain a boost in older individuals, suggesting that working out could help maintain brain function as we age.

The small-scale study by researchers at the University of Iowa looked at 34 adults between 60 and 80 years of age who were healthy, but did not do regular physical activity.

Each participant was asked to ride a stationary bike in two separate exercise sessions for 20 minutes, starting with a light level of pedaling before increasing to moderate intensity with a more strenuous resistance.

Participants underwent a brain scan before and after each session to look at activity in regions known to be involved in collecting and sharing memories, and completed a memory test.

They also took part in a regular exercise program, involving pedaling on a stationary bike for 50 minutes three times a week for three months. One group engaged in moderate-intensity pedaling, while the other had a lighter workout in which the bike pedals moved for them.

The findings, published in the journal Medicine & Science in Sports & Exercise, showed that even after a single exercise session, some participants' brain scans showed increased connectivity between the medial temporal, which surrounds the hippocampus, the part of the brain involved in memory, and the parietal cortex and prefrontal cortex, two regions involved in cognition and memory.

These participants also performed better on the memory tests, with individuals in both the moderate and lighter-intensity exercise groups showing mental benefits.

The team also found that the participants experienced the same amount of cognitive benefits and improved memory from a single session as they did from the longer, regular exercise program. 

However, the boost in cognition and memory from a single exercise session lasted only a short while for those who showed improvement.

The study also showed that some participants showed little to no gain in cognition and memory, a finding backed up by previous research which has shown that the benefits of exercise can vary.

"One implication of this study is you could think of the benefits day by day," said Michelle Voss, the study's corresponding author. "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."

"The benefits can be there a lot more quickly than people think," she added. "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."