Exercise is known to increase neurotrophic factors such as vascular endothelial factor, brain-derived neurotrophic factors (which increase the growth of new neurons, synapses, and blood vessels) and decrease overall inflammation (which increases brain aging).

This study (on 150 twin pairs) showed that the link between leg power and brain aging were not explained by genetics or shared environment. Additionally, other developmental, lifestyle and health measures indicated that reverse causation is not likely, and the effect is not likely to be mediated through frailty (as measured by telomere length), or disease. Finally, other fitness measures, such as forced expiratory volume or grip strength, were not associated with brain aging when leg power was excluded.