Fast

A better article about Karl Meltzer who is going to attempt a speed record of the Appalachian Trail.

Running the Appalachian Trail won't be a walk in the park by any means. Meltzer says about 2,000 of the 2,200 miles are rough and rocky, more difficult to navigate than the smooth trails he knows in Utah and the West.
That's partly why he chose the trail.
"It's not necessarily running hard, it's a lot of hiking. The [trail] is technical, it's hard, it's hilly, and it's not going to work that way. It's time spent on your feet just moving forward," Meltzer said.

Best of luck to you Karl!