Whole food fueling ultramarathon: why ultrarunners are ditching gels

 

Whole food fueling during an ultramarathon means: real ingredients as fuel, no synthetic gels, no artificial flavors. It's not a lifestyle choice. It's race management. If you want the full picture of fueling for long endurance efforts, first read the complete guide to energy bars and endurance sports. Here I will address one specific question: why are more and more ultrarunners moving away from gels?

What is whole food fueling and why do ultrarunners choose it?

Whole food fueling is an approach where, during exercise, you opt for food based on recognizable, minimally processed ingredients instead of synthetic gels or isolated sugars. In the ultra world, races from 50 km to 100 miles and more, this approach is growing rapidly. Not because it's a trend, but because practice demands it.

A fruit performance bar is a compact fuel source during exercise, built for race conditions. I designed my 25g bar specifically for that moment: enough carbs to be relevant, small enough to eat while running. Per bar, you make a direct contribution to your carbohydrate intake without stopping, without forcing chewing, without pushing a brick down your throat.

The switch is not a matter of taste. It is a performance decision driven by one specific problem: stomach complaints. Nausea, cramps, and vomiting during long endurance efforts are among the most reported reasons why runners do not finish their race or significantly lose pace.

Why do gels cause so many stomach problems during an ultramarathon?

A standard energy gel typically contains 20 to 25g of carbohydrates in concentrated form. The sugar concentration of many gels is high. This means your stomach has to draw water from surrounding tissue to process the gel. At kilometer 5, that's manageable. At kilometer 60 of a 100km race, with a stomach already under pressure, that's a real risk of cramps and nausea. If you want to clearly see the trade-off between the two products, read energy bar vs. energy gel: when to use what.

Then there's the composition. Many gels contain artificial colors, flavors, and preservatives. After four, six, eight hours of exercise, the sensitivity to these substances increases in many athletes. The stomach becomes more selective. What worked in training no longer works on race day. I work exclusively with fruit and without artificials. That's not a marketing choice, that's functionality. More and more cyclists are making the same switch, for the same reason: why cyclists are swapping gels for a clean fruit energy bar.

Whole food fueling reduces the burden on your stomach. Real fruit ingredients naturally contain fiber, water, and a different sugar structure than isolated synthetic carbohydrates. Digestion proceeds differently. Not necessarily faster, but more stable, with less chance of acute reactions during prolonged exercise. Moreover, a 2:1 glucose/fructose mix demonstrably accelerates gastric emptying and fluid absorption versus glucose alone, a mechanism that Jeukendrup and Moseley recorded in a controlled study in 2010.

How does the 2:1 glucose/fructose ratio work?

Your gut uses two separate transport channels to absorb sugars. Glucose goes through one channel, fructose through the other. Two separate routes mean that your absorption capacity is higher than with a product that burdens only one channel. With a 2:1 ratio, two parts glucose to one part fructose, you work both routes simultaneously without overloading either. This is not theory. It is the basis behind the entire shift from single to multiple carbohydrate products in sports nutrition.

Currell and Jeukendrup showed in 2008 that a 2:1 glucose/fructose mix improved time trial performance by approximately 8% versus glucose alone, because your body burns more external carbs and spares your internal glycogen reserve. Rowe and colleagues confirmed the same picture in runners in 2022: better performance AND significantly fewer stomach complaints than with a standard carbohydrate solution. That second part, fewer stomach complaints, is precisely why this matters to ultrarunners.

My 25g fruit performance bar delivers, based on 80g of carbohydrates per 100g, about 20g of carbs per bar, divided over these two routes. Concrete, measurable, and built on fruit instead of powder.

How many carbohydrates do you need, and how do you distribute that?

For endurance exercise longer than 2.5 hours, the recommendation is between 60 and 90g of carbohydrates per hour for trained athletes who use both transport channels. King and colleagues found in 2019 that 90g per hour in a 2:1 ratio was the optimal dose over three hours of cycling. More was not better: higher doses impaired performance. In ultra-endurance, it's less about the peak per hour and more about consistency over the entire distance.

Important: you don't get those 60 to 90g from bars alone. The setup that works:

• Sports drink as the main source. A drink with 6 to 8% carbs, 500 to 800 ml per hour, provides 30 to 60g per hour and keeps you hydrated at the same time.
• 1 to 2 fruit performance bars per hour. Each 20g carbs, in the same 2:1 ratio. This is your regular, solid-form component that your stomach recognizes.
• Possibly 1 gel in the final. At high intensity at the end, if you need a quick boost.

Together, you easily reach your 60 to 90g per hour, without overloading one channel or one texture. That's a workable protocol for an ultramarathon, and it relies entirely on whole food fueling.

What makes a fruit performance bar suitable for trail and ultra?

Trail running places different demands than a road race. The terrain is unpredictable, your heart rate varies more, climbs and descents alternate. This affects blood flow to your intestines, and thus how stably your fueling is processed. A fruit performance bar scores concretely on four points here:

• Size. 25g fits in any vest pocket. No wrapper fuss on technical terrain.
• Consistency. No liquid, no gel that spills or sticks to your gloves.
• Digestibility. Fruit-based without artificials reduces the risk of stomach complaints during long exercise.
• Carbohydrate density. 80g carbs per 100g. Functionally compact, without fillers.

The combination of clean ingredients and a functional 2:1 carb structure makes the bar a direct competitor to the gel. Not as a snack, not as a treat, but as fuel during exercise. That's the category. That's the position. By the way, the same logic works just as well on a training ride: the ideal fuel for your bike ride.

How does a fruit performance bar compare to other race options?

Product	Carbs per 100g	2:1 ratio	Without artificials	Risk of stomach problems
Standard energy gel	60-70g	Variable	Rarely	High
Energy bar (commercial)	50-65g	No	No	Medium
Dates / dried fruit	60-70g	No	Yes	Low-Medium
Eagle fruit performance bar	80g	Yes	Yes	Low

The bar performs better than dried fruit in carbohydrate density, has the 2:1 ratio that commercial bars lack, and combines that with a clean ingredient list that synthetic gels cannot match. That difference between clean and artificial is clearest when you compare fruit energy bar with classic candy. No overclaim, just a product specification you can check on the label. My bars are made by a certified Belgian production company (BRCGS Food Safety, ACS), 100% vegan, gluten-free, and lactose-free.

No gel. No brick. Fuel.

Fruit as a raw material for sports nutrition is not nostalgia. It is a functional choice. Fruit naturally contains glucose and fructose together with fiber, moisture, and a sugar structure that your body processes differently than isolated synthetic carbohydrates. I build on that: fruit × effect. The ingredients are not decorative. They are the fuel.

Whole food fueling in an ultramarathon is not the easy way. It requires planning, a protocol, and knowledge of your own stomach. But the runners who do it, do it for one reason: it works. Fewer stomach problems. More control. A stronger second half. No gel. No brick. Fuel during exercise, which still works at hour ten. Fuel your flight.

 

Choose your fuel