Karl Meltzer

Ultrarunner Karl Meltzer has long dreamed of setting the speed record for crossing America's Appalachian Trail. Now he sets out for his third and final attempt to run the 3,523km (2,188 miles) in less than 46 days, 8 hours, 6 min.

In 2010, ultramarathoner Karl Meltzer embarked on his attempt to run the Pony Express route, crossing the Rocky Mountains from Sacramento, California to St Joseph, Missouri, USA. This is his story.

An inside look at Scott Jurek's 2021 attempt at breaking the Appalachian Trail speed record.