They will run 100 miles.
That's 100 miles through the Wasatch Mountains.
The winner will finish in about 20 hours or so.
The rest of the field, those dedicated to one thing — finishing — hope to complete the run somewhere in front of the official 36-hour cutoff. Many, of course, won't finish.
But at least 22 people have finished the Wasatch 100 Mile Endurance Run 10 or more times — Richard Gates is going for his 21st finish.
Only two people out of five starters finished the first race in 1980. Last year, 230 started, 131 captured that hard-to-describe feeling at race's end.
"I think every one of us would say that every finish is just as surreal as the one before — every finish is just weird," said Phil Lowry, going for his 10th this year. "When you get there, it just blows your mind that you did it — that never gets old."
Derek Blaylock, for example, will try to join his father, David Blaylock, in the elite club of finishers who have completed the Wasatch 100 at least 10 times.
After three failed attempts and then her first finish last year, Wendy Holdaway will be back for another run at it.
Lowry usually finishes the Wasatch in about 28 to 30 hours, that's around 9 a.m. or later at the Homestead Resort in Midway — the race starts near Kaysville and follows mostly trails and dirt roads through the mountains.
Race director John Grobben predicted this year's overall winner will be Karl Meltzer, who has four wins under his belt, including a victory last year.
"He's about the quickest guy in the group," Grobben said.
Nate McDowell, who holds the course record in under 20 hours, is running but he has been injured lately, Grobben said.
Seattle resident Krissy Moehl Sybrowsky took the women's title last year with a time of 23 hours, 49 minutes and 47 seconds.
"I don't see anybody challenging her," Grobben said. Ann Trason's 1998 finish, 22 hours 27 minutes, is still the women's course record.
In year's past the weather has beaten up on runners — sometimes extreme heat in the day or bitter cold and/or wet conditions during the night.
Lowry, an avalanche contract observer for the Utah Avalanche Center, said this weekend's race should only be framed by wind and rain — in between cool, sunny times, nearly perfect running weather, he added. As the unofficial race meteorologist, Lowry will check in with the National Weather Service to give runners a more up-to-date report before Saturday's 5 a.m. start.
One person who plans on being at the finish line Sunday — rain or shine — is Nadine Cook; she's Lowry's mother-in-law. She was at the finish line last year when Lowry crossed.
Lowry admits he knows as much about quilting as Cook knows about why ultra-runners torture themselves. But Lowry said Cook is beginning to understand. "She said, 'You know, I didn't understand what this is all about until now and it's completely different than what I thought,'" Lowry recalled. "That was profound."