Born in 1987, and raised in the mountains of Catalonia, Spain, Kilian Jornet learned to ski before he learned to walk. “Before taking the first steps on foot, we had our first kilometers on skis,” he wrote of his sister’s and his first experience outdoors on snow. Today, Jornet, age 23, is an elite ski-mountaineer and a competitive ultra runner. His resume cites victories in North America and Europe as significant as the 166km Ultra-Trail du Mont-Blanc in France, and California’s Western States Endurance Run, a 100-mile ultra that he won last month in 15 hours, 34 minutes. We caught up with Jornet to talk gear, the Western States, and the limits of a human body on the run. —Stephen Regenold

Gear Junkie: Congrats on the Western States! What did you do differently this year than last year?
Kilian Jornet: All! Last year, I didn’t take water, I just drank at the aid stations, and I didn’t eat enough. Just two sandwiches and some gels. And I did not eat salt pills last year. This year, I ate and hydrated differently, and I ran at an easier pace. I didn’t force myself all the way. I fought to control legs cramps.

What was the most difficult part this year?
No real difficult points this year! I ran very conservatively, and I ran very stable and finished well. I kept some energy in case someone was coming [from behind trying to pass] or if I was to have any physical problems [later in the race].

What did you eat during the race?
Gels every 30 minutes from the Foresthill checkpoint to the finish. I took Aliment Liquide [liquid food] two times. Salt pills at one or two an hour for most of the race. And a few sandwiches at aid stations with tomatoes, ham and cheese.

I heard that by the finish line you had gained a kilo of weight. Was this all water?
No water because I peed a lot of times, all the way! But I was eating a lot!

How much did you drink per hour on the event?
A half-liter to one liter per hour.

Head to toe, what gear and apparel stood out?
Salomon made me special gear for the race. I wore custom shorts and T-shirt that were prototypes. Very light and breathable. My custom Salomon shoes were 170 grams each, lightweight. And I had a cap with neck protection.

Most interesting gear?
My Salomon “hand bottles”! These were prototype gloves with a soft bottle built in on back. They carry a half-liter of water each and collapse as you drink.

In broad terms, what does it take to be an ultra-runner?
A lot of motivation, love of the mountains, and a love to run.

Is ultra-running more physical or mental?
It is impossible to separate physical and mental — if you have mental, you construct the physical. It’s not just a percentage of one or the other.

How does your body feel after running 100 miles nonstop?
Bad! Legs and feet hurt. But also the bio-rhythm changes, and I need two days to sleep and eat normal again!

Is 100 miles a limit for most people, or will ultra athletes continue to up the distances in years to come?
My longest run was 280 kilometers. Some races in Europe are more than 300k in very technical areas and with lots of elevation, like the Tor de Geans. For first place, you need a time of more than 70 hours! But for anyone, the distance is not the issue. It is how to increase your best distance or longest run, from 10 kilometers to ultra.

—Read more about Kilian Jornet at www.kilianjornet.com and on a new micro-site by Salomon, “Kilian’s Quest.”