The chaos of rocks offered a challenge that proved too formidable for me. I can handle steep hills as long as I can set a steady pace. Fox Run’s boulders gave me no quarter, no opportunity for rhythm, no chance to stop and enjoy the view. The whole of my concentration was given to getting around the next stony protuberance. So I struggled, resting between outcrops to gather my strength and sweating like I was in Miami. When I conquered the last and relatively easy third of the trail — which was precipitous but smooth — I felt nauseous. Some kind of problem — maybe blood sugar, maybe dehydration — tormented me and I could blame that problem on the path I had just clamored up. Unequivocally.