A documentary following two attempts by Gary Robbins to finish the Barkley Marathons (2016 and 2017). I recommend first watching the documentary titled "The Barkley Marathons: The Race That Eats Its Young" (available on Netflix) to get an idea of what the race is all about.

Robbins ran again this year (2018) and was the only person to finish the fun run (but didn't make the cutoff for lap 4).

The best VDOT calculator I've found (for finding suitable training paces according to Jack Daniels' running formula).

A calculator which uses the result of a recent race to "generate training paces, race prediction, with adjustments for temperature, body weight and altitude. This calculator works by estimating your V̇O2max and using that to predict your race times and training paces."

It's a shame Jack Daniels requested to have the vdot calculation removed from this calculator in an attempt at commercializing his research to the detriment of the wider running community.

"In 1880, Frank Hart wowed audiences at New York’s Madison Square Garden by walking 565 miles in six days."

A nice overview of Jack Daniels' training method.