Kilian Jornet, a 29-year-old trail runner, skier and mountaineer from the Catalan region of Spain, has been acknowledged as of one of the greatest endurance athletes of this generation. The 5-foot-7, 128-pound Salomon-sponsored athlete has won countless trail running races around the world (including the Western States 100, Pikes Peak Marathon, Mt. Marathon and Hardrock 100 in the U.S.) and set numerous Fastest Known Time records going up and down mountain peaks, including two ascents of Mt. Everest in May.

On Sept. 1, he’s racing the Ultra-Trail du Mont-Blanc, a 103-mile loop around the Mt. Blanc massif that begins and ends in Chamonix, France, and also goes through Italy and France. Kilian Jornet has won the race three times but hasn’t competed in it since 2011. [Editor’s note: Jornet finished second in the 2017 UTMB behind François D’Haene.] We caught up with Jornet recently to get his views on trail running, racing and mountaineering.

How has trail running changed in recent years?

“It’s interesting to see the changes that have happened in the last 10 years in the sport. My generation was the first to start running longer ultras before turning 20 and in our early 20s. Before that, it was not very common. In the U.S., there are a lot of athletes who have come right from college with a background in track and field like Sage Canaday or Jim Walmsley or Zach Miller or Rob Krar and have a strategy that’s about going fast from the very beginning. And that creates a challenge for everyone else to realize we need to train more on flat terrain so we can keep running fast. And that’s really created a interesting races and strategies.”

How do you train now?

“When I was young, I had a coach who told me what I should be doing. That was good because normally I wanted to do much more, but she taught me the importance of doing less before races. Since I was 17, though, I have trained on my own. I have tried to follow the science of training. It’s important to know the basics of what you’re doing and why. But I also like to try a lot of different things in training, like to go out for a long time without eating. So, for example, I stopped eating one day but I just keep training, for four hours in the morning and in the afternoon. In those situations your speed and power disappear but you keep your endurance, I learned how my body reacts in situations like that. It’s good to explore the extremes in training so you can know your body.

“My training from November to May is only on skis, about 2-4 hours in the morning and one hour in the afternoon. In the summer, from May to October, it’s all about running and climbing in the mountains, from as little as 2-3 hours in the morning but it could be as much as 9 or 10. If I do less than 5 hours, I’ll normally do an hour or so in the afternoon. But if I go longer in the morning, I’ll only train once that day. That’s about 1,200 hours of training per year and about 600,000 to 700,000 meters per year.”

Is there a doping problem in trail running?

“I don’t think there are many people who are doping in trail running, but I think it’s important for the next generation to be able to show that it’s under control and it’s not something that normally happens. And that’s why it’s important to have anti-doping controls. I think it’s sad that people are doping to try to reach their goals. I think it means they put their goal ahead of a strategy of how to get there, and I think it means they’re unhappy somehow with something. If all elite athletes will be tested at least, once, it will help to stop it and stop athletes who are thinking about it.” (Jornet has been an advocate of the WATTS volunteer clean sport initiative that tests athletes and makes results public. He has also been regularly tested through WADA-sanctioned testing in ski mountaineering.)

Have you developed a tolerance for suffering?

“Suffering is never the objective. It’s a feeling that you experience, and there are a lot of different ways to suffer: mentally or physically. But you learn to overcome that suffering. For example, you can suffer once from the cold, but then you think afterwards ‘I didn’t get frostbite or didn’t die, so it’s not that dangerous.’ And the next time you’re in that situation, you might not be entirely comfortable, but you know it’s not bad either and you don’t suffer the same way you did before. You can’t always push harder in those conditions, but you can feel confident in situations in which you were suffering or afraid previously.

“When I was going up Mt. Everest, I was suffering from my stomach but I knew that was like suffering from stomach anywhere, so it was OK. I knew I didn’t have edema or hypothermia and so I knew I wouldn’t die because you don’t die when you’re sidelined with stomach problems. So I knew I had to go slower and needed to stop more times. No, it’s not a good feeling, but you’re already up there and it’s closer to go to the summit than to go down so you keep pushing.”

How have your cumulative experiences helped you adapt?

“Everything you do and experience can make you feel more comfortable in those situations. It’s important to go through that so you can draw from it. The last two years I have been trying to put myself in situations in the mountains where before I was afraid or not confident. I would try to to 20-30 hours alone, and not in perfect conditions, pushing my limits in technical situations. What happens is you get used to being in those situations.

“At the moment you are able to take away any emotion, it’s when you are ready and best prepared to push your limits. If you have euphoria and are happy, you would make bad decisions because you would not see all the risk. If you have panic and are scared, you will panic and start to not control yourself. You need to take the emotion away and just be rational and think about the technical and physical aspects of whether you can do it or not. If it’s “no,” it’s best to go home or not go on. If it’s “yes,” you have to decide whether you want to accept the risk or not. It’s about spending hours and hours in those situations. Maybe there is a way to do it through meditation, but I think you become more confident if you have more knowledge of the conditions like that and experiences like that. When you get back you can let the emotion come back and you can think, ‘I am well, I am alive and I am happy from the journey and am done.'”

What are your thoughts about this year’s UTMB?

“It’s not because I want to win the race that I want to go to an event. It’s more that it’s a competitive field or a good race. Racing always puts you in that situation. When you go to a race, you have to ask if you are training as hard as the others and that motivates you. I just love racing, it’s fun, it’s a game. When you are a kid, you want to beat the other kids, and it’s the same in ultrarunning or mountain running.

“The cool thing about UTMB is that there are 15 guys who are strong and I don’t think there has ever been a field in a 100-mile race like that before. Usually it’s 2 or 3 or 4 runners that are that strong, but never a big big field like this. That’s interesting to me. All the people in the race know how to run 100 miles. So technique, tactics and being competitive will vary. Everyone will bring their own strategy and that will make for an interesting race. Some will start super strong, some will start slower. Some are better on uphills, some better on downhills or on flats. That’s what will make the race interesting.”

In 2016, you and American Jason Schlarb tied for the victory at the Hardrock 100, but most people felt you could have beaten him. Why were you OK with finishing together?

“It’s a nice feeling to win a race, but it’s also a good experience to finish second or third or to finish with someone. With Jason, I did’t know him before. I only met him during the race, and we started talking and we knew we had a lot of common friends and I learned about the things he was doing. It was a cool journey. In a long distance race like that, we chatted and ran together for 20 hours, so it didn’t make sense to finish in a sprint. That didn’t feel right. It’s more of a journey.”

“In other races, I would give everything to have the victory. This past winter in ski mo, we were sprinting to have the victory by 1mm. And that’s cool too. It depends on how the race goes. Every race is different. If you have been fighting with someone, it’s fun to sprint to the finish. If you’ve been sharing the race together, it’s nice to share the victory.”

Kilian Jornet won the Hardrock 100 in Colorado for the fourth straight year in July, doing so after dislocating his left shoulder near mile 13.

Do you still have the same competitive fire you did 10 years ago?

“I am still very competitive. The way I have changed is that I used to be training more specifically for ski mountaineering races in the winter and trail running races in the summer. If I am starting a race and have the possibility to win it, I want to win it. But before I was more focused on that so I used to train in a way that would mean taking it easy the day before a race so I was able to win it. Now if there are very good conditions in the mountains the day before a race, I would still go climbing or running and wouldn’t worry about what would happen the next day. I like to enjoy more things and based on my experience I think I can do more things can keep my fitness. It’s more that I see races now for staying in shape and being able to do a lot of things in the mountains.

“What I like to do is always evolving. The more you do things, more things you want to do. I don’t like to specialize in anything, I am happy to do a big expedition in the Himalaya or a technical climb or fast ascent in Chamonix and then be able to run a short race and one week after an ultra race the next week, and then go in the winter and focus on skiing or doing skimo races. When you do different things and put yourself in different situations, you know yourself in different ways and you have different emotions. So I like to do different things to feel different. In the future, I will still race because I think that is fun, but I don’t put as much of a priority on that. Instead I put the priority on everything at the same level.”