Twelve weeks of training produced a significant increase in α-Klotho, brain blood flow, and hippocampus volume, and correlated with an improvement in episodic memory in older adults [190], but another study with a longer duration (26 weeks) in middle-aged adults at risk of AD found no significant increase in α-Klotho and no correlation with cognitive changes [183]. The gene discussed is KL; the disease is Alzheimer disease.