Icon Xtri, high altitude and energy intake – why your nutrition can be crucial

When discussing extreme triathlons like Icon Xtri, it's easy to focus on elevation gain, cycling sessions, and FTP. But after analyzing races with over 5,000 meters of climbing on the bike, marathon running in mountainous environments, and many hours at high altitude, we consistently see the same thing:

The energy and hydration plan can be the difference between a strong finish and a long struggle to the finish line.

Icon Xtri in Livigno starts at an altitude of 1,816 meters and takes participants to significantly higher levels during the day. The combination of altitude, long climbs, and many hours of effort places completely different demands on the body than a traditional long-distance triathlon.

What happens at high altitude?

At high altitude, oxygen availability is lower. The body responds by:

• Breathing more
• Consuming more fluid
• Using more carbohydrates as fuel
• Working harder for the same effect

Even for an acclimatized athlete, the energy cost can be higher than at sea level. This means that nutrition becomes even more crucial.

Days before the race

Many athletes focus on resting before a big race but forget to adequately refuel. The goal for the last 48-72 hours should be to maximize muscle glycogen.

Recommended carbohydrate intake

8-12 grams of carbohydrates per kilogram of body weight per day. A 75 kg athlete therefore needs 600-900 grams of carbohydrates per day.

Suitable foods: pasta, rice, potatoes, white bread, sports drinks, fruit, juice.

It's advisable to reduce the amount of fiber-rich foods, high-fat foods, and foods that typically irritate the stomach.

Hydration balance before start

One of the most common mistakes in high-altitude races is that the athlete arrives at the start slightly dehydrated. A higher breathing rate increases fluid loss even in the days leading up to the competition.

Practical advice: drink regularly, ensure urine is light yellow, supplement with electrolytes or sports drinks in the days before the start, avoid forced drinking of large amounts of water.

Race day – energy must be consumed early

In extreme long-distance races, waiting until you feel hungry rarely works. By the time energy depletion is felt, it's often too late.

Breakfast

Three to four hours before the start: 2-3 grams of carbohydrates per kilogram of body weight. For a 75 kg athlete: 150-225 grams of carbohydrates.

During the bike leg

In a race like Icon Xtri, the bike leg is the longest opportunity to replenish energy. This is also where many races are decided.

Carbohydrates

Ambitious long-distance athletes should aim for 90-120 grams of carbohydrates per hour, provided the stomach is trained for it. Examples: sports drinks, gels, chews, simple energy bars.

Fluid

Normally 500-800 ml per hour. In hot weather, the need may be higher.

Sodium

Approximately 500-1000 mg of sodium per hour. Sodium helps the body absorb and retain fluid during long competitions.

When cramps occur

Many believe that cramps are always due to salt deficiency. The reality is more complex. In extreme mountain races, cramps are often seen despite well-planned energy and salt intake. In such cases, it's often about neuromuscular fatigue – the muscle has simply been working close to its capacity for a very long time.

Long climbs like Stelvio primarily stress the quadriceps, glutes, and calves hour after hour. The feeling many describe is: I wasn't out of energy. I just had no legs left.

The run reveals everything

Many athletes get off the bike feeling like their energy is still there. Then the marathon running begins. If the cycling was too costly muscularly, it shows immediately: no bounce in the step, no power on uphills, difficulty increasing pace even though the heart rate feels controlled.

This is why energy intake on the bike is so important. The marathon often serves as a receipt for how well one succeeded during the first 8-10 hours.

After the finish line

Recovery begins immediately.

First hour

The goal should be: 1-1.2 grams of carbohydrates per kilogram of body weight, 20-30 grams of protein, fluid with electrolytes.

First 24 hours

Prioritize carbohydrates, protein, sodium, and fluid. Many focus on calories but forget to restore fluid balance.

Summary

In races like Icon Xtri, it is rarely the strongest cyclist who performs best. It is often the athlete who starts the race with full energy reserves, consumes enough carbohydrates during the bike leg, maintains fluid balance at high altitude, manages sodium intake throughout the day, and comes to the run with muscles that can still produce power.

When the altitude increases and the hours become many, there are no shortcuts. A well-thought-out nutrition strategy is not a detail in the preparations. It is part of the performance.

Coach's lesson: In extreme Xtri races, we more often see athletes underestimate the total stress from altitude and long climbs than underestimate their FTP. Therefore, the energy and hydration plan should be trained as thoroughly as the intervals leading up to the race.