Researchers are beginning to understand the precise impact various forms of exercise have on the heart. 

    Scientists at Massachusetts General Hospital have found that 90 days of athletic training produces significant changes in cardiac structure and that the type of change varies with the type of exercise performed. Their findings – which may some day benefit heart disease patients – appear in this month's Journal of Applied Physiology. 

    The researchers studied two groups of student athletes at Harvard: endurance athletes – 20 male and 20 female rowers; and strength athletes – 35 male football players. 

    Echocardiography studies – ultrasound examination of the heart – were taken at the beginning and end of the period. Participants followed normal training regimens. 

    Both groups had significant overall increases in the size of their hearts. For endurance athletes, the left and right ventricles – the chambers that send blood into the aorta and to the lungs, respectively – expanded. The heart muscle of the strength athletes, however, tended to thicken, a phenomenon that appeared to be confined to the left ventricle. 

    The most significant functional differences related to the relaxation of the heart muscle between beats – which increased in the endurance athletes but decreased in strength athletes. 

    研究人員已經開始了解不同運動形式對心臟的確切影響。

    馬薩諸塞州總醫院(Massachusetts General Hospital)的科學家們發現，90天的運動訓練會對心臟的結構產生明顯影響，并且變化的形式與運動形式相關。他們的這一發現刊登在了本月的《應用生理學雜志》(Journal of Applied Physiology)上，或許未來會有助于心臟病患者的治療。

    研究人員以哈佛(Harvard)的兩組學生運動員為研究對象：一組是耐力運動員，20名男性賽艇運動員和20名女性賽艇運動員；一組是力量運動員，35名男足運動員。

    在研究期的始末都對心臟進行了超聲波檢查。研究對象均按正常訓練計劃進行訓練。

    兩組運動員的心臟大小總體上都有明顯的增加。耐力運動員的左右心室（分別負責將血液輸送到大動脈和肺）均有所擴張；力量運動員的心肌則有所變厚，這似乎僅限于左心室。

    不過，最顯著的功能性差異在于心跳之間的心肌放松——耐力運動員的心肌放松增加了，而力量運動員則減少了。