I cranked my ankle a few times out west and it still hurts so I tested it on the treadmill. I watched Jamil Coury's "Run Steep Get High" vlog from the Hardrock 100 miler. If you've ever wanted to see inside this race, this is a terrific video. He managed to record a clip every mile for the first 56 miles and he finished 9th overall.
https://youtu.be/Kvjd9sEVv-k