From The You Know Not The Hour Department:

Asbury Park Press: Runner who collapsed and died during Olympic marathon trials had enlarged heart

Elite distance runner Ryan Shay, who collapsed and died Saturday during the U.S. men's marathon Olympic trials, had been diagnosed with an enlarged heart but cleared by doctors, his father said. "The thing that made him such a great runner may have killed him," Joe Shay told The Associated Press. An enlarged heart like Ryan's translated into extra endurance — crucial for a distance runner.