It's Science - Fitter legs means fitter brains

I guess this belongs in the category, "We knew it all along."

Researchers at King's College London have found that muscle fitness as measured by power in the legs is strongly associated with an improved rate of ageing in the brain. 

Scientists studied a sample of 324 healthy female twins from the TwinsUK volunteer registry over a ten-year period from 1999, measuring various health and lifestyle predictors. Researchers were, therefore, able to control for genetic factors affecting changes in cognitive function. 

Thinking, learning and memory were measured at both the beginning and end of the study and it was found that leg power was a better predictor of cognitive change than any other lifestyle factors tested. Generally, the twin who had more leg power at the start of the study sustained their cognition better and had fewer brain changes associated with ageing measured after ten years.

 Here's the article, and you can pat yourself on the back, you smarty.