Physical activity trajectories and their associations with health outcomes in older adults with mild cognitive impairment or dementia: a national cohort study.

"Declarations Conflict of interestThe authors have no conflicts of interest to declare. Ethics approvalThe ethical approval and experimental protocols for this study were obtained from the institutional review board of Peking University (IRB00001052-11015). Consent for publicationAll authors have approved publication. Human and animal rightsAll data used were following the ethical standards of the institutional review board/international ethics committee for each center and with the 1964 Helsinki Declaration and its later amendments. Consent for publicationAll authors have approved publication. Informed consentPrior to participation, informed consent was obtained from all participants. Conflict of interest The authors have no conflicts of interest to declare."

"Funding None."