A while back I was researching into the rare cases of heart attacks in runners. The most classic in point was the legend of the marathon runner, Pheidippides.
I read through the wiki page http://en.wikipedia.org/wiki/Pheidippides, which lead me to an article on sudden death in athletes, to http://en.wikipedia.org/wiki/Sudden_death_(athletes)
It seemed that these articles referred to defects that were never diagnosed. In 2012, I saw a TedX video by a Cardiologist runner, explaining that too much running may be unhealthy.
Recently this research popped up again with Dnews.
it basically mentions the same thing, more details were available in the Tedx talk.
I love running, If I can I would do it everyday, But according to research, I might need to drop it down a notch. Darwin was wrong, it is not the survival of the fittest, it is the survival of the moderately fit.
Based on this research, now most of my workout is often not to vigourous, maybe once a week is speed work, once a week long relax run, everything else in moderation, but at least one rest day a week. Generally runners still live 6 years longer than non-runners. But everything in Moderation. I would like to attain and maintain 10km under 1 hour.
I don’t need to run fast, I just need to run, I see myself running even when I am above 60 years. Hope to see you running then 🙂