Long distance runners being healty and fit is a MYTH.
it need not be unhealthy.
These 3 deaths are a numbers game. Big marathon event, tens of thousands of athletes. Every year otherwise healthy (often young!) men drop dead, on the soccer field, in a skiff etc. A bad year means a number will die during a big event, one or two deaths are very common. There's a small percentage of people that have an undetected congenital heart anomaly that can lead to sudden death.
