Unlike many ultramarathons that are defined by their distances, a “backyard” ultra is a race that has no end distance; The winner of the race is the last runner standing. The Quarantine Backyard Ultra will begin at 7 A.M. MDT on April 4th, 2020 and by nature of the race’s unusual format could end at any time. SI"s Jessica Smetana Breaks down the Quarantine Backyard Ultra and how Dave Proctor has amassed such a following willing to go virtual.