MAPT and Alzheimer disease: By contrast, the Wisconsin Registry for Alzheimer's Prevention of cognitively healthy late middle-aged adults suggested that sedentariness was associated with a greater CSF Aβ burden, whereas moderate PA, but not light or vigorous PA, was associated with a favorable profile of CSF biomarkers for AD (e.g., higher Aβ42, lower total tau/Aβ42 ratio, and lower phosphorylated-tau/Aβ42 ratio) [25, 26].