Elite American ultramarathoners treat race aid stations like NASCAR drivers use pit stops: in, out, and on the trail again as fast as possible. While a runner may drink their way through an aid station or grab a handful of snacks as they head out, they consume the vast majority of their food and water on trail.

In longer and more technical American ultramarathons, elite runners sometimes spend a little extra time at one or two aid stations. There, they eat more than usual and change their clothing, shoes, or other crucial gear. Even at these stops, which last four, five, or perhaps 10 minutes, time is still of the essence.

Elite European ultramarathoners have an alternate aid-station ethic. Even at a long race’s early aid stations, they linger for a couple minutes, eating and drinking as much as they can in that short period of time. Most elite Euros carry some food and water with them on trail to enhance their aid-station intake. That said, these runners still consume most of their calories while in aid stations.

I’ve had the opportunity to closely watch Catalan endurance freak Kilian Jornet race the 100-mile distance three times. At the 2010 Western States 100 (WS100), I watched him race Euro-style, eating and drinking in aid stations, leaving only a couple of them with a water bottle. The day was hot and he became dehydrated before slowing to a third-place finish.

At the 2011 WS100, he ran with some sweet, custom-made water bottles, a half liter for each hand. He raced American-style, taking his food and drink on the trails. He stayed on top of hydration and won.

At the 2011 Ultra-Trail du Mont-Blanc (UTMB), Kilian chowed down in the aid stations. When it was time to leave, he headed out with a small pack containing the race’s mandatory equipment and little in the way of food and water. Sometimes, I saw him leave with a small, plastic flask containing liquid. That’s all it took for victory there.

Late this summer, I chatted with a group of runners about Kilian’s ability to adapt to this array of racing conditions. That is, they said, to consume hundreds of calories at once and to consume those same calories over a few hours of running are two different, digestive animals. And, to run 100 miles without carrying water must mean that Kilian drinks less liquid than most runners. What gives, we all asked?

My interest was piqued, so I chatted with Kilian about his nutrition strategies. I trust that what he shared, especially what he ate and drank during his first win at the 2008 UTMB, will surprise you as much as it did me. There’s inherent value and fascination in learning how one elite man propels himself to victory. Though I know that you’re going to eat and drink more than Kilian does, some of his general principles are also applicable to each of us who takes to the trail.

iRunFar: I gotta’ know, during a mountain ultramarathon, how many calories do you consume? Are there certain foods you rely on?

Kilian Jornet: I have no idea. I never count calories. I eat a lot more now than when I first started. At my first UTMB, I drank maybe three liters and ate two sandwiches!

For food, I eat Overstim’s Aliment Liquide 640, a glass every four hours. I eat small sandwiches with jam and Nutella. And I eat gels during the last four or five hours of racing.

iRunFar: That’s pretty crazy, your first UTMB! Do you ever have stomach issues in getting certain kinds of food to digest or in food not tasting good?

Jornet: If I eat normal food, for me, it is not a problem. Too many gels are not good for my stomach. I sometimes have a problem with hydration if I drink a lot of very cold water. That gives me digestion problems.

iRunFar: How much fluid do you take in during a mountain ultramarathon? Do you drink just water? Or do you drink some sort of sports drink?

Jornet: For the drink, it depends on the conditions of the race. This year, I drank 13 liters of water at WS100 and five liters at UTMB.

I drink just water in long distance. How much depends on climatic conditions. Under normal, cool, European racing conditions, I drink one liter every two or three hours. The maximum I will drink if it’s very hot is between .7 liters and one liter per hour.

If I’m racing at night or in the last hours of a race, I maybe also have Coca Cola or Red Bull.

iRunFar: A Red Bull-amped Kilian is a fun image. At some races, you don’t carry much food or water with you between aid stations. And, once you’re in an aid station, you eat and drink a lot. What’s up with this?

Jornet: When I train, I never carry water or food. The mountain gives me everything I need, the rivers and fruits. Normally, I train for five or six hours with nothing. I am used to not having it.

In races I eat a lot at aid stations! They are every one to two hours on the trail. This is not long time to go without eating.

iRunFar: At this year’s WS100, you carried water and food between aid stations. How did that work out?

Jornet: Yes, that race is really different than Europe’s races. Really hot. It is for the heat that I carried one liter of water between every aid station. I also took salt pills every one hour at first and every 30 minutes at the end.

Why? I remembered every moment of last year’s experiences!

iRunFar: Do you notice that runners in the US and runners in Europe use different fueling and hydrating tactics? When you go to different places to race, is it hard to adapt?

Jornet: Is important to study every single race, the temperatures, rivers, aid stations. It is important to plan a strategy and to adapt to what happens in the race.

European races are more cold and you don’t need so much water, and the backpack is mandatory. In the USA, there is no mandatory equipment but you need to carry a lot of water.

Call for Comments (from Bryon)

What do you think of Kilian’s fueling and hydration strategy? Any lessons that you’ll take from it?