Women with stronger legs have better cognitive function and sharper mind

This 10-year study of 324 female twins (ages 43-73) found women with stronger legs had 18% less cognitive decline. Comparing identical twins with different leg strength ruled out genetics. Brain scans showed stronger women had more grey matter. The study measured processing speed and visual memory only. The evidence shows that leg strength predicts cognitive aging trajectory rather than a simple snapshot comparison - brain ages less. Limitation: observational design cannot prove building leg strength improves cognition—only that they're associated. Effect is real but modest. The most important limitation is that this observational design leaves open the possibility that some unmeasured third factor (like overall better health, higher motivation, or subclinical metabolic differences) causes both stronger legs and better cognitive aging.