The concept of ischemic preconditioning was first put forward by Dr. murry in the United States in 1986. Simply put, it means that repeated, short-term, non-invasive and harmless ischemic preconditioning training can stimulate the emergency mechanism of human immune system and produce and release endogenous protective substances (such as adenosine, bradykinin, nitric oxide, etc.). Participate in myocardial protection and energy metabolism) to alleviate and resist longer-term ischemia. Effectively avoid cardiovascular and cerebrovascular diseases such as cerebral infarction and sudden cardiac death.