长期大强度耐力运动对心脏的不利影响

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

长期耐力运动能防治慢性疾病,尤其是与心血管相关的慢性疾病,如心衰、冠心病和高血压等,这一点已经被广泛认可。很多人都积极参与大强度耐力运动,如半程/全程马拉松、超级马拉松、铁人三项和山地自行车等。但越来越多的研究表明,"运动员心脏"并不完全是有利变化,大强度耐力运动给身体带来有利一面的同时还对心脏有不利影响。一次大强度耐力运动时需氧量持续增加,心输出量长时间保持在较高水平,心脏负荷增大,心脏的4个腔室会过度伸展,导致心肌纤维撕裂,造成微损伤,而且,运动时儿茶酚胺持续升高,再加上运动时产生的自由基增多,两者通过诱发和增加炎症反应来恶化这一损伤。这些损伤虽然在1周内可以恢复,但长期重复损伤则会形成"瘢痕",造成不利的心肌重塑,为心律失常和心脏功能障碍建立了结构基础,进而诱发心源性猝死。

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.