The idea of my heart blowing up in a marathon has been giving me more than a little, er, heartache, certainly since this recent story of Chris Gleason, a 10:00 IM triathlete, and about-to-be 3:00 marathoner, about my age, who left behind his family with only 1/4 mile to go in last fall's Philadelphia marathon.
Of course, I'm conscious of the plane-crash versus car-crash phenomenon, and recognize that the statistics certainly favor us runningprofs over the "Duh Bears" guys from SNL.
A member of a triathlon list-serv to which I belong just shared this Runner's World article, which summarizes a New England Journal of Medicine study. Time reported it as well. Apparently, we're OK, no longer being 22. The only problem is running triathlon.
Here are a few more links to reports on studies (1, 2, 3), which the same list-serv group member shared. (I'd like to attribute, because it's really interesting stuff and I appreciate her sharing it, but I have a rule against naming people by name, so I won't.) A one-sentence summary: everything you know is true -- you shouldn't run long if you aren't properly trained (I've violated this injunction more than once); you need to hydrate (I'm getting much better at this); digging deep at the end isn't healthy (fortunately, I'm really good at walking at the end!).