Women who want to protect themselves against cognitive decline as they age could get a leg up through legwork, according to a new study that found “a striking protective relationship” between aging women’s leg power and cognitive changes over 12 years.
Researchers in England reached this conclusion after analyzing leg muscle power and cognitive performance among 324 healthy female twins at baseline (average age, 55; range 43-73) and then 12 years later. After controlling for health and demographic variables, they found that the women who had increased leg power at baseline scored better on tests of brain processing speed and visual memory 12 years later than the women with lower leg power at baseline. Overall differences were modest but consistent, with a 40-watt leg explosive power (LEP) increase correlated with an average 3.3 years’ lower cognitive age.
Authors of the study assert that the use of twins further strengthens their conclusions, because they were able to compare 10-year differences among “discordant” twins—twins with similar genetic traits and childhood environmental influences, but whose leg power was different at baseline. As with entire group comparisons, researchers found that the twin with the greater leg power tended to demonstrate slower cognitive decline than her sister. The strongest differences were noted in dizygotic (fraternal) twins; less so in monozygotic (identical) twins.