APOE and Alzheimer disease: Our research (Smith et al., 2011; Woodard et al., 2012; Smith et al., 2014; Smith et al., 2016), and those of others (Head et al., 2012; Galle et al., 2023), suggest that exercise may be particularly beneficial for cognitively intact, healthy older individuals (ages 65–80 years) who are at genetic risk for AD based on having one or both apolipoprotein E4 (APOE ε4) alleles.