If vigorous exercise is good for you, why have so many former world-class athletes died of heart attacks?
The most likely cause is previous use of anabolic steroids and human growth hormone (HGH). Doctors at the Massachusetts General Hospital found that apparently healthy, older former long- term users of anabolic steroids have weaker left ventricles, the major pumping chamber of the heart. This markedly increases their risk for heart failure and heart attacks (Circulation: Heart Failure, July 2010).
Many world class athletes in sports requiring extreme strength took anabolic steroids from the early 1960s on. When these athletes were in competition, their training made their hearts stronger than those of other people their age, and available tests failed to show any heart muscle damage. With aging, the hearts of all people weaken because they lose muscle fibers. As these former users of anabolic steroids reach middle and older age, tests can detect the heart muscle weakening that increases their risk for sudden death from heart attacks.
Taking large amounts of HGH can cause sudden death from irregular heart beats. HGH causes heart muscle to grow far more than its nerves do, and everyone loses nerves with aging. The effect of former HGH use on the hearts of older athletes has not been documented, but we do know that people who have acromegaly, a brain tumor that produces large amounts of HGH, are at increased risk for sudden death from irregular heart beats.