If you're trying to find Chris Garcia on a Saturday morning, focus your search dozens of miles deep in the Santa Cruz Mountains or halfway up nearby Mount Diablo. He'll be on foot, but if you want to catch him you'll have to move fast.

Garcia, an HHMI investigator at Stanford School of Medicine, reserves his Saturday mornings to train for ultramarathons, grueling tests of endurance that stretch between 30 and 100 miles. On an average Saturday, he runs 20 to 30 miles—on narrow, winding, mountainous trails—with a handful of training partners. During the peak of his training season he follows up with another 20-miler on Sunday and shorter runs throughout the week, for a total of 70 to 80 miles.

Garcia wasn't always a runner: in high school he was on the tennis team, and during graduate school he rowed a single scull with the Baltimore Rowing Club. Then a postdoctoral fellowship took him to San Diego, where he competed in triathlons and marathons.

“Then one day, I'm flipping through the channels on my TV and see this story on ultramarathons,” says Garcia. “I just remember being totally transfixed. When you hear about people running 100 miles, you have one of two reactions: you either think it's completely crazy, or you think ‘Hey, I should go do that.’ For me, it made complete sense.”

In the past decade, Garcia has run more than 75 ultramarathons, including nine 100-milers, all over the United States. Races usually start around 4:00 a.m. to take advantage of cool morning temperatures. The 100-milers take Garcia between 20 and 30 hours to finish, depending on the elevation and how mountainous the terrain is. He wears a headlamp and runs through the following night, pausing only at food and water stops offered every 10 or so miles.

Illustration: Peter Arkle

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