At Trudvang community center in Lånke, Lunder Backyard 12t starts at 09:00 as a backyard-style ultramarathon built around one repeated loop. Each runner has one hour to cover 6.706 km, or 4.167 miles; anyone who finishes faster uses the spare minutes to eat, change layers, sit down, or get ready before the next hourly start.
The race ends only when a single runner completes a full loop alone, which is the Last Man Standing format in its bluntest form. Hell Ultraløperklubb organizes the event, with Lars Erik Gylland as race director. The course record stands at 40 rounds, set by Børje Cato Moen, for a total of 268.24 km.