On March 5, I accepted and took on the David Goggins 4x4x48 challenge. The rules were simple; run four miles, every four hours, for 48 hours. Goggins removed barriers for entry. This made it free, virtual and you didn't even have to run. You could walk, bike, workout, row, stretch, whatever. Ultimately, you just had to do something for 40 minutes every four hours for two days.