Is cardio good for you? (marathon runners and heart attacks)

Visit PaNu for an interesting article on some research linking marathon running and an increased risk of heart attacks.

It appears oldish (57) marathon runners are more likely to have experienced myocardial damage than sedants (a word I just invented meaning sedentary controls).

Now, this recent post is just as interesting as it appears that researchers in the US have not only been able to replicate the results, but get statistically significant results. And those results indicate that marathon runners have an increased risk factor compared to people who were going in for this specific heart scan. That is, people who have decided or been told that they should get this scan - obviously that isn't a control group one would expect to have the healthiest results.

Of course, it might not actually be the cardio that causes the increased heart problems, there are many factors which could correlate. For instance, it could be the lifestyle of marathon runners and Harris points this out towards the end of both posts.

The only marathon runner I've read about is Japanese novelist Haruki Murakami. I am fairly certain in his book What I talk About When I Talk About Running (which I loved) he discussed eating only a small amount of red meat, sticking predominantly to vegetables, rice and fish. And as anyone who has spoken to me in the last year will attest this isn't a diet that I believe can be backed up by research.

I also wonder if running, as a high impact sport, causes more inflammation than other long distance cardio. Perhaps this extra load on an athlete's body could have an effect on heart health? Thus, further studies on long distance cyclists and swimmers would be enlightening; I imagine they have similar lifestyles yet use different muscle groups, and, if my wild assumptions are correct, suffer fewer joint injuries.