NOVA· Season 35 · Episode 3Marathon ChallengeS35E03·October 30, 2007·1h·PBSExplore what it takes—physically and mentally—for novice runners to make it through a classic test of endurance.Streaming on (US) See allSharePreviousGhost in Your GenesS35E02NextSputnik DeclassifiedS35E04 · 6.5Keep going