Adverse Effects of Long-term Intensity Endurance Exercise on the Heart

It's well established that long-term endurance exercises are highly effective for prevention and treatment of many common chronic diseases,especially cardiovascular relative chronic diseases such as heart failure,coronary heart disease,hypertension and so on.So,many of them engage in intensity endurance exercise,including half-marathon,marathon,triathlon,mountain cycling and so on.However,an accumulating body of circumstantial evidence suggests that the athlete's heart is not completely benign.There is no doubt that intensity endurance exercise is benefit to body health,but it's also have adverse effects on cardiac.A bout of intensity endurance exercise requires increasing oxygen consumption,and sustained high-level outputs in a long time,and these increase the cardiac load.However,with protracted efforts,these high volumes can overstretch the chambers,eventually disrupting cardiac muscle fibres and causing micro-tears in the myocardium.The presence of sustained exercise-induced elevations in catecholamines and pro-oxidant free radicals worsen the situation by adding inflammation to the injury,leading eventually to scarring and remodel of the cardiac structures.These changes result in a substrate for arrhythmogenesis and myocardial dysfunction,and even induce sudden cardiac death.