In the 70s the idea become that if you could run a marathon you would be immune to heart attack: this is a urban myth.
Risk? 1 to 100 000. The presenter enters a discussion with friend and editor in chief Amby Burfoot at Runner's World.
Perhaps endurance running does not add years to your life, nor adds life to your years. This is the possible conclusion that the presenter is showing.
No single step you can take in your life to ensure robust health and remarkable longevity than a habit of daily exercise.
Like any potent drug:
Troponin level goes up at the end of marathons: heart muscle has died, micro stretches from growth. A sacred component for cardiologists. Not a big deal once in a while. It heals. But along the decades ... Phidippides cardiomyopathy.
Finding: After a 15-30 year study, it does not add longevity if you run further than 25 miles a week. On speed same thing: at 8 miles per hour same happens, the benefits went away.