BDNF and Alzheimer disease: RE applied in old animals or animal models of AD, using exercise programs lasting between 4 and 12 weeks, increased BDNF levels in the hippocampus (Özbeyli et al., 2017; Vilela et al., 2017; Jafarzadeh et al., 2021; Kim et al., 2021; Lee et al., 2022; Rahmati et al., 2022).