A Fastest Known Time (FKT) is the speed record for a running, hiking or cycling route.[1] Unlike most endurance sports competitions such as marathon world records, FKTs are self-organized and done alone or in small groups.[2] FKTs are most popular on long trails suitable for thru-hiking or ultramarathon trail running such as the Appalachian Trail,[3] the Pennine Way,[4] and the John Muir Trail.[5]