Whether Running is good to your health?

For the runners, we debate all the time:
How many miles per week is good enough?

Wall Street has an article last Friday:
The Exercise Equivalent of a Cheeseburger.
Basically this article says that too much
running is not good for you, especially if you
run more than 30 miles per week.

From my own experience, 6-7 mile run, 10 mile
run and hal marathon run is very esay and comfortable.
I will feel a little bit pain somewhere if I
ran over 15 miles. So I think I will find
my comfortable zone.

I do know that exercise is different from health.
It is very similar to: investment will not all
make money. And over-training will injury the body
body as well.

Though I ran 2.5 hours Monday, I spent 2 hours
on foam roller. And yesterday, I rode bike for
one hour and walked for two hours for the
cross-training. Seems like that I spent too much
time on the exercise now.