APOE and Alzheimer disease: We found: (1) no association between physical activity and plasma Aβ42/Aβ40 or plasma p‐tau217 cross‐sectionally; (2) physical activity was not associated with PET‐derived SUVR Aβ 7 years later; (3) age, sex, and APOE4 did not modify the relationship between physical activity and AD biomarkers; and (4) accounting for the intercorrelation among activities through compositional analysis did not alter the results.