If some is good, then more is better.  It’s the American way, right?  A society of excess.  From money (“The root of all evil.”), to possessions (“You can’t take it with you.”), to food (3rd highest obesity rate in the world).  Well, apparently the same is true of exercise.  I preach to my clients all the time about excess in the negative.  Encouraging down time and the fact that sometimes less is more.  A new study by Dr. James O’Keefe at St. Luke’s Hospital in Kansas City, and confirmed by review at the Mayo clinic does, in fact, say that too much is too much.  Specifically targeted at chronic aerobic training and the phenomenon of “Ultra” sports.  I have written before about the oxidative damage that these things can cause and the links to premature aging, and hypothetical (however, unproven) possibilities of the cancers and early heart problems.  Well, this seems to confirm it.  The condition, as currently named, is called Phidippides Cardiomyopathy.  It’s named after the Greek soldier who ran the first 26.2 miles to deliver information about the battle of Marathon.  He died.  Well, it appears that extreme endurance training (over 60 minutes) creates significant structural and biochemical alterations in the cardiac muscle of the heart.  These markers return to normal fairly quickly when you stop exercising, but over the course of time are showing to leave areas of patchy scarring on the heart tissue and, in some cases, abnormal heart rhythms.  Extreme runners have shown better than 1/10 to have evidence of this scarring and a 5-fold increase in risk of cardiovascular disease than runners of non-extreme status.  There also seems to be a law of diminishing returns with exercise.  That after about an hour, you get less out of it than you put in.  So, really, you are working backwards.  So just like with anything, moderation is the key.  Yes, exercise is good.  But even a good thing in excessive quantities can be turned into a bad thing.  Be smart.