Dustin Joubert, M.A.
Changes in the normal structure and size of the heart and its various chambers can indicate exercise training adaptations or disease. Of particular concern is the size and shape of the left ventricle, the hardest working chamber of the heart, which is responsible for ejecting blood through the entire body. It is generally accepted that the type of exercise training causes specific changes in characteristics of the left ventricle. Endurance exercise tends to increase the volume or internal diameter of the left ventricle, whereas strength training may increase the mass or thickness of the left ventricular walls. Increased left ventricular mass is considered a cardiovascular risk factor in the general population and may be associated with increased work of the heart related to excess body mass and blood pressure. Ultrasound imaging technology allows cardiologists to measure these heart structures in individuals and compare them to healthy norms. There has been some concern whether or not former professional football athletes are at increased risk for cardiovascular complications due to larger body and heart sizes. This is a particular concern with retired National Football League linemen, who have been shown to have a higher rate of cardiovascular death than both non-linemen and the general population. In these retired athletes, increased heart size was significantly associated with football position as well as body size and systolic blood pressure. In our review of freshmen Division I collegiate football athletes, it appears that over 30% have cardiac measures that exceed normal, absolute ranges. However when presented relative to body size, fewer athletes show heart structure measurements outside of normal, healthy ranges. Changes in cardiac structure have not been determined in football athletes throughout the active course of their collegiate and professional careers. The adverse changes in cardiac structure in retired professional players were observed many years following retirement and were primarily present in athletes with excess body mass and high blood pressure. Therefore heart structure and function should be a concern not only during a football athlete’s active playing career, but even more importantly into retirement.
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Croft L, Belanger A, Miller M, Roberts A, Goldman M. Comparison of national football league lineman versus nonlinemen of left ventricular mass and left atrial size. Am J Cardiol. 2008;102:343-347. http://www.ncbi.nlm.nih.gov/pubmed/18638599