Your nutrition strategy for the UTMB® will also rely on energy gels and bars for solid fuelling. With the massive variety available on the market, choosing can feel overwhelming. Beyond brand preferences and flavours, here is our advice for getting it right.
How to fuel during the race?
Solid food satisfies the need to chew while supplementing your caloric intake. You need to strike a delicate balance across several factors: gastrointestinal tolerance, energy requirements, the craving for solid and savoury food, and maintaining a consistent intake rhythm.
The overall goal is to achieve 60 to 90 g of carbohydrates per hour across all sources (gels, bars, isotonic drinks), and up to 90 to 120 g/hr for trained runners combining glucose and fructose—two carbohydrates that use distinct intestinal transport pathways to raise digestion limits. The proportion of solid food is not set in stone: it mainly depends on your gut tolerance and the race phase. As a benchmark, studies on 100-mile races show that finishers consume an average of around 70 g/hr compared to less than 45 g/hr for runners who DNF, highlighting just how critical it is never to underfuel your effort.
Solid intake can consist of half a ripe banana, a fruit paste, an endurance energy biscuit or a small energy bar every 60 to 90 minutes. Alternatively, fuel at aid stations during lower-intensity stops with cooked rice, potatoes, a small sandwich or broth. After eating solid food, drink plain water rather than energy drink to avoid overloading the stomach with overly concentrated fuel.
Make sure to chew thoroughly and take small mouthfuls. Chewing eases the workload on your stomach: food swallowed too quickly sits longer in the gut and diverts blood flow away from working leg muscles. Sluggish digestion can also trigger stomach distress during exertion. Practice chewing slowly and thoroughly during training, and test your carbohydrate intake beforehand to train your gut to tolerate higher amounts.
Should you choose energy bars or gels?
It is partly a matter of personal taste, but the optimal strategy is to carry a mix of both. Opt for well-balanced bars formulated for long endurance efforts: eat them when stationary or during lower-intensity sections when you have time to chew thoroughly. Gels are better suited to high-intensity efforts or towards the end of the race when chewing and digestion become harder. Vary flavours while sticking to a brand or product line you have already tested and tolerated well: never switch products at the last minute, even if a race partner is handing out free samples.
A key logistical detail to keep in mind: at the UTMB®, only one sports nutrition brand is provided along the course, and its gels are available at just five aid stations. If your plan relies on gels, carry your own. Full details can be found in our article on aid stations.
Frequently asked questions
How many grams of carbs per hour should you target on the UTMB®?
Between 60 and 90 g of carbohydrates per hour in total, combining solids and liquids, up to 90 to 120 g/hr for well-adapted runners using a dual glucose-fructose source. The balance between gels, bars and energy drink depends on your digestive tolerance, which must be tested beforehand in training.
Can you try new nutrition products on race day?
No, it is best to stick strictly to products already tested in training, even when free samples are handed out along the course.
Gel or energy bar: which is best in the final stages?
Gels. After hours of intense effort, chewing and digestion become increasingly difficult, and liquid or semi-liquid fuels go down much more easily.
Find out more
- Nutrition and hydration strategy for the UTMB®
- Energy drinks for the UTMB®: how to choose?
- Aid stations and race nutrition during the UTMB®
- Gut training for ultra-trail
Photo credits: Clément Dumas.
