After six months of scientifically advanced training, three of the world's most elite distance runners set out to break the two-hour marathon barrier. These pioneers go on a global trek to defy the unthinkable and break the two-hour feat, from testing in wind tunnels and running labs in the United States, to balancing training with their day-to- day lives in eastern Africa, to the final heart-pounding race in Italy.

Release : September 20, 2017

Website : http://channel.nationalgeographic.com/breaking2/

Duration : 55 minutes

Rating : 8.30