FNDC5 and Alzheimer disease: This study aimed to investigate the effects of 8 weeks of pretreatment with coenzyme Q10 (CoQ10) and high‐intensity interval training (HIIT), both individually and in combination, on FNDC5, irisin, BDNF, and amyloid‐beta (Aβ) plaque formation in the hippocampus of Aβ‐related AD rats.