91热爆

There are some sporting targets that are iconic... Breaking the four minute mile, Claiming a clean sweep of Grand Slams in tennis in the same season or taking all 10 wickets in a cricket innings.

All of those have of course been done, but one that remains tantalisingly close, but as yet unattainable is running a marathon in less than 2 hours.

It's a subject that journalist and author Ed Caesar has poured years of his life into investigating. The result of which are in his book "Two Hours: The Quest to Run the Impossible Marathon"

PHOTO: Ghirmay Ghebreslassie of Eritrea celebrates winning the men's marathon at the 15th IAAF World Athletics Championships Beijing 2015 August 22, 2015 (CREDIT: ChinaFotoPress/ChinaFotoPress via Getty Images)