In this context, our present study showed that aerobic exercise improved the cardiac structure and function through inhibiting oxidative stress and ER stress-induced apoptosis by activating the FGF21/FGFR1/PI3K/AKT pathway in post-MI heart, but fgf21 knockout partially weakened the cardioprotective effect of aerobic exercise in mice with MI. The gene discussed is FGF21; the disease is myocardial infarction.