Ran partway of the MLK 50k Fat Ass. Toughest section was the north side connector to the top of Spencer Butte, more of a climb than a run or hike. My calves were burning by the time we got to the top, not so much from effort but the angle at which they were stretched for such duration. I know I've got to do more of that. Traction was bad, and folks were slipping pretty good. We should not have done that climb as we impacted the trail.