Participants with high total tau concentrations with medium physical activity had a 58% slower rate of cognitive decline (estimate, –0.028 standard deviation unit [SDU] per year [95% CI, –0.057 to 0.002 SDU per year]; difference, 0.038 SDU per year [95% CI, 0.011-0.065 SDU per year]), and those with high physical activity had a 41% slower rate of cognitive decline (estimate, –0.038 SDU per year [95% CI, –0.068 to –0.009 SDU per year]; difference, 0.027 SDU per year [95% CI, –0.002 to 0.056 SDU per year]), compared with those with little physical activity. Here, MAPT is linked to Mental deterioration.