David created a challenge known as the 4x4x48 Challenge, or the Goggins Challenge, where your objective is to run 4 miles every 4 hours for 48 hours. I first heard about it last year, and after gaining some popularity within the ultra community, I decided to take a crack at it.

I hadn’t heard of the Shakori 40 until last month when I was telling a couple of running buddies about my recent DNF at the Bull Mountain Epic 100k. It sounded intriguing as the format seemed straightforward: 10 laps around a 4-mile course of trails and hills.