Your latest PR in trail running could actually be a world record—here's the fitness sub-culture that tracks the stats
Corbis Images

To win a race, you usually have to register, show up at the starting line, and dash with hundreds or thousands (or hundreds of thousands) of other runners. But not always: There's a sub-culture in trail running that's making it possible for runners to set time records on routes that aren't "official" race courses. (Find out the pros and cons of trail running vs road running.) It's called setting a Fastest Known Time or an Only Known Time (FKT and OKT, respectively.)

Here's how it works: There's a website, where you log in, peruse routes from others, and attempt to beat their FKT or challenge people to run your route and beat your OKT. "An FKT attempt offers the competitive nature of a race, while still preserving the basic nature of why we got into trail running to begin with," says Craig Lloyd, an Altra athlete who owns an FKT for the Zion Double Crossing, a series of trails in Zion National Park strung together to cover 48 miles with 10,000 feet of elevation.

And some of the courses-like the Zion Double Crossing-are seriously grueling. "With fewer (or no) aid stops available, the runner has to understand the course better, know where to obtain water (and if it should be filtered), and be more aware of when to pull back and when to push, since failure along the course rarely allows for an easy exit or rescue," says Lloyd.

But you don't have to be a trail runner (or an elite athlete), or even become a member of this site to set a record. Think of it this way: If you have a route you do from your house, you already own the (unofficial) OKT. is solely for more advanced trail running. You can also use tools like MapMyRun to challenge others to try your OKT and beat your time. Or you can search other new routes near your zip code and try to beat the fastest time. (And since 81 percent of you get competitive even with the woman next to you on the treadmill, we're thinking you'll get a kick out of this!)