Periodically, I'll come across a knuckleheaded report like this one from Minneapolis:
Marathon Man’s Heart Damaged by Running?
Of course, the obligatory story about how a cardiologist came to the rescue and "saved his life" with a stent follows. In other words, a stent purportedly saved the life of this vigorous man with no symptoms and high capacity for exercise.
Does vigorous exercise, whether it's marathon running, long-distance biking, or triathlons, cause coronary disease? Should all vigorous athletes run to their doctor to see if they, too, need their lives to be "saved."
Let me tell you what's really going on here. People with the genetic pattern lipoprotein(a), or Lp(a), tend to be slender, intelligent and athletic. For genetic reasons, these people gravitate towards endurance sports like long-distance running. Lp(a) is a high-risk factor for coronary disease. It is the abnormality present in the majority of slender, healthy people who are shocked when they receive a high heart scan score or have a heart attack or receive a stent. (I call Lp(a) "the most aggressive known coronary risk factor that nobody's heard about.")
The association between endurance exercise and heart disease is just that: an association. It does not mean that exercise is causal. Having seen coronary plaque detected with heart scans in many runners, virtually all of whom demonstrated increased Lp(a), I believe that Lp(a) is causal.
Unfortunately, the man in the Minneapolis story, now that his life is "saved," will likely be advised to take a statin drug and follow a low-fat diet . . . you know, the diet that increases Lp(a).