This is one of those rare videos that gets better every single time you watch it. First time through - waiting for the fall the entire time, thinking this next step it's surely coming. Second time through - watching in utter fascination. Third time - getting out to the stopwatch to see how long he lasted.
I'm not sure if this guy is a marathon runner or not but he covered some distance on this video. In the end, the black ice wins. It always wins.
Some would call this surface the perfect texture for running. Very low impact and it's dry snow so your feet don't get wet.