MAPT and Mental deterioration: Among participants with low total tau concentrations, medium physical activity was associated with a 2% slower rate of cognitive decline (estimate, –0.050 SDU per year [95% CI, –0.069 to –0.031 SDU per year]; difference, 0.001 SDU per year [95% CI, –0.019 to 0.021 SDU per year]), and high physical activity was associated with a 27% slower rate of cognitive decline (estimate, –0.037 SDU per year [95% CI, –0.055 to –0.019 SDU per year]; difference, 0.014 SDU per year [95% CI, –0.007 to 0.034 SDU per year]), compared with little physical activity.