The December issue of Trail Runner is on news stands now. For the “Faces” feature, I interviewed Colorado ultra runner Brooks Williams. He’s as tough as the come. The beginning of the piece is below. For the rest check out “Embracing Adveristy” in Trail Runner.

Brooks Williams, 28, of Colorado Springs, Colorado, is hoofing his way out of the May Queen aid station on his way to the 11,071-foot summit of Sugarloaf Pass in Colorado’s 2011 Leadville Trail 100-Mile Run. It is the first major climb, less than 20 miles into the race, and Williams has just hacked up a wad of mucus that resembles an olive-green cinnamon gummy bear in both size and consistency.

The phlegm is an indicator of the infection that has permanent residence deep in his lungs. For the next 86 miles he will continue to cough up secretions, first in this gummy stage, than as something that resembles tapioca pudding, and, finally, as common, stringy snot. Despite all sounds and appearnaces, the chest-rattling hacking is good for him: some mucus in his lungs is emptying.

When he was five-and-a-half-months old, Williams was diagnosed with cystic fibrosis (CF), a chronic life-threatening respiratory and digestive disease…