20-minute bursts of exercise are hugely beneficial for the over-60s

A 20-minute burst of exercise performed regularly is all it takes to help keep the brain sharp into old age, a new study suggests. Scientists at the University of Iowa have discovered that the over-60s do not have to complete long stretches of activity in order to feel the benefits.

They analysed 34 people between the ages of 60 and 80 to see how short periods of riding a bicycle impacted their brains. Scans showed it led to increased connectivity between the hippocampus and the parietal and prefrontal cortexes.

This is particularly important as these areas are responsible for memory and cognition, which are known to deteriorate as individuals age. Keeping them connected and active can mean leading an independent life for longer and not having to rely on others to perform everyday tasks.

Dr Michelle Voss, lead author of the study, said: “One implication of this study is you could think of the benefits day-by-day. In terms of behavioural 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 study, the participants who were healthy but didn’t exercise regularly, rode an exercise bike for 20 minutes at a time. In the first instance, the bike was set up to have light resistance, which was then upped to strenuous for the second stint.

As well as a brain scan after each bout of exercise, the individuals were also given a memory test. This consisted of a series of eight faces being rotated every three seconds and the participants being asked if the one they were shown matched with the example they saw two cards previously.

What the scientists found was that the subjects performed better on these tests after a workout, although the benefits did not last a long time. To continue seeing surges in connectivity and improved cognition, individuals need to ensure that they’re exercising regularly.

Dr Voss added: “The hope is a lot of people will then keep it up because those benefits to the brain are temporary.”

A second phase was then introduced to the study and participants were asked to use an exercise bike for 50 minutes three times a week for three months. The results of this showed improvements in brain scans and memory tests, reinforcing the importance of keeping up an exercise regime.

When compared to the effects of a 20-minute burst of exercise straight afterwards, the 50-minute stints were not any better. This shows that shorter spells of physical activity can be just as effective for improving brain performance than shorter ones.

The researchers summarised: “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.”