Some recent research published in the
Journal of American College of Cardiology has been reported as saying that too much running is bad for you. The research looked at about 1000 runners and 3000 non exercisers and found that all cause mortality did improve with exercise. It also found that high intensity running did not necessarily improve mortality rates. You have to subscribe to read the whole article but as with all research I am sure there is more to this than just the headline. What worries me more is that the headline is likely to put people off running at all despite the evidence.
It does seem that someone has read the article fully and it seems that this is reheated research from 2012 and is co-authored with a well known "running kills you" academic. The Runners World article http://www.runnersworld.com/health/the-supposed-dangers-of-running-too-much picks some good holes in the data that seems unbalanced and takes no account of gender.
