On average, people with stronger, quicker legs tend to maintain healthy brains for longer, which means runners and cyclists can give themselves a pat on the back.
The researchers studied the relationship between leg muscle fitness and cognitive functioning in 324 pairs of identical twins over a 10 year period from 1999 to 2009. This way, all genetic influencers on brain power could be accounted for.
They measured a wide range of lifestyle factors that differed between the twins, and analysed ability to think, memorise and learn both at the beginning and the end of the study.
Out of every influencing factor, including time spent reading and learning, having powerful legs was found to be the most important determiner of ability to think. This, in turn, is directly related to amount of exercise done. More details are published in the journal Gerontology.
Claire Steves, lead author of the study, said: “Everyone wants to know how best to keep their brain fit as they age. Identical twins are a useful comparison, as they share many factors, such as genetics and early life, which we can't change in adulthood.”
It's compelling to see such differences in cognition and brain structure in identical twins, who had different leg power ten years before. It suggests that simple lifestyle changes to boost our physical activity may help to keep us both mentally and physically healthy.