Fastest Known Time

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

Informal, unverified speed records have long existed on named trails, but the invention of handheld GPS devices, such as GPS watches or personal locator beacons, made it significantly easier and more reliable to collect and compare fastest times on a route even in the backcountry. The modern FKT movement has been cataloged on a tracking website, fastestknowntime.com, founded by outdoor enthusiasts Pete Bakwin and Buzz Burrell, who coined the term "FKT" in the year 2000.

FKT popularity increased most recently due to trail races being cancelled due to the COVID-19 pandemic. While there is no governing body for certifying FKTs, the site acts as an informal arbiter, sometimes requiring additional certification like photographs and pre-announcing your intent to attempt a record. In March 2022, FastestKnownTime.com was sold to Outside Inc., the parent company of Outside magazine and other outdoor media companies.