Stowe, Vermont

Held every two years because of the complexity of the course, the Mozo Double Up challenges runners to climb up and over Mount Mansfield TWICE over the course of 11 miles. This is not your average trail run. You will be going up or down most of the time, with zero opportunity to lose your focus. There are no-fall zones (meaning if you fall, serious injury or death may result), and quad-busting descents over some of the most technical terrain you can find. If you don’t run hills, don’t consider this race. If you do run hills, run more of them, and run them often.

Learn more here: https://www.ironwoodadventureworks.com/mozo-double-up