At 8am (the top of the hour) everyone starts the 4.25-mile course. Everyone is allotted 1 hour to complete the loop. Thus, for example, if you finish in 45 minutes, you rest and recover until the top of the next hour at 9am and you start the 4.25-mile loop again. You must be at the start line at the top of the hour or you are out of the competition. This continues until the Last Man or Woman standing.