Long-distance running has repeatedly caused sudden death, which has caused people to worry about the safety of long-distance running. Among the types of sudden death, cardiogenic sudden death accounts for the majority, of which deaths due to heart rate arrhythmia account for 80%. When it comes to causes, acute myocardial infarction is the most common, and there are also congenital abnormal cardiac diseases that can cause arrhythmias. As far as the current medical development is concerned, there is no good means to screen for cardiogenic diseases, especially the underlying diseases are difficult to detect even by physical examination. Therefore, sudden cardiac death is one of the hot research topics in the medical field. The reason why sudden cardiac death occurs after strenuous exercise is that the sudden death victim is unaware of his or her own related diseases, and usually lacks exercise, and sudden strenuous exercise leads to cardiac ischemia and hypoxia, and overload eventually becomes a precipitating factor for sudden death. Some young people suffer from myocarditis, should rest more, strenuous exercise can easily trigger sudden death. Do not say that people with underlying cardiovascular disease, even healthy normal people, once the heart overload may also be an accident.