In a recent survey, I was asked about my preferred running surface:

I was a bit surprised by one of the options provided:

“Road”, “Trail”, and “Track” were standard enough answers, and while “Mountain” is not exactly a surface, I understood what it meant. But “Sky”? If I could run on that, it’d really be something. Would running on the sky count as flying? Either way, I thought it sounded fun.

A bit more research quickly disabused me of that notion. Apparently, skyrunning is specific type of mountain running, about which I was heretofore unaware. Races take place on particularly steep grades, at 6,600 feet or higher. No thanks!