I mentioned several times that broccoli is good for you. But, odds are, you could guess that means that you shouldn’t switch your diet to one of just broccoli. Everything in moderation……right?
I’ve also suggested, on occasion, that exercise is good for you. But is there such a thing as over-exercise? A new study that appeared in The Journal of Applied Physiology and mentioned in The New York Times, suggests that you can go a little too far.The researchers studied a group of subjects who had all trained very extensively for Olympic and National competition as well as members of a group known as the 100 Marathon Club– membership, as the title suggests, is reserved for individuals who have competed in 100 marathons or more. The subjects were divided by age categories and compared to a group of older subjects, none of whom were endurance athletes.
Using MRI technology, the researchers found that the older group of endurance athletes showed some heart muscle scarring, known as fibrosis, that none of the younger athletes or older non-athletes had shown. The fibrosis can lead to a hardening of the heart muscle which can, in turn, create irregular heart function and heart failure.
In a related study, another group of researchers found that they could create the same results in mice. They also found that when they removed the mice from their training regimens, their hearts returned to normal and the scaring disappeared after a matter of weeks.
So does this mean you should stop exercising Absolutely not. The results are for endurance athletes who are training, over many years, for one endurance event after another. Casual exercise, two or three times a week, will still provide heart-healthy benefits.
I think the lesson to be drawn from the study is that, while cardiovascular exercise is beneficial for the heart, it is also necessary to rest and perceive rest as part of the normal training cycle. Think of it as a cardiovascular Yin and Tang effect– if you go in one particular direction, it is also necessary to go in the opposite direction in order to achieve balance. Rest is good.
Too much of a good thing isn’t necessarily a good thing.