When preparing your race pack for the UTMB®, do not forget your nutrition and hydration strategy. Beyond choosing products, it is above all how you consume them, in terms of quantity and frequency, that makes the difference in such a long event.
How much and how often should you eat?
Aim for between 60 and 90 grams of carbohydrates per hour for a long-distance race such as the UTMB®, from all sources combined (isotonic drink, gels, bars). Trained runners can even reach 90–120g/h by combining glucose and fructose, two sugars that use different intestinal absorption pathways and help push back the digestive limit. This amount supports the effort without causing digestive issues, provided you have trained your digestive system for it beforehand: studies of 100-mile races show that finishers consume an average of around 70g/h, compared with less than 45g/h for runners who withdraw. Try to consume some every 20 to 30 minutes for a steady energy supply and to avoid major energy dips.
Favour small, regular doses over large, widely spaced amounts: the aim is never to feel urgently hungry and to avoid rushing for food at aid stations. If the temptation is strong, take the time to eat enough in small bites, even if it costs you a few minutes: you will regret it less than indigestion a few kilometres later.
Digestive training (gut training)
Between 30 and 90% of endurance runners report digestive issues during exercise, one of the main causes of withdrawal in ultra events. The good news is that the ability to absorb carbohydrates during exercise can be trained, just like cardiovascular fitness or muscles. Find the full protocol (gradual increase over several weeks, products to use, time required) in our dedicated article: gut training for ultra-trail.
Isotonic drink
An isotonic drink, containing mineral salts and carbohydrates, is essential for your hydration during the race. Find our complete guide to choosing one and getting used to it in our article Energy drink for the UTMB®: how to choose?.
Energy gels and bars
For the solid part of your nutrition, energy gels and bars are the backbone of your race. The balance between solid and liquid intake is not set by a strict rule; it mainly depends on your digestive tolerance and the stage of the race. Find all our advice on choosing them and knowing when to consume them in our article Energy gels and bars for the UTMB®.
At aid stations
The event's aid stations complement your personal strategy with water, drinks and solid food, sometimes including hot meals. Find full details in our article Aid stations and nutrition during the UTMB®.
Frequently asked questions
How many carbohydrates per hour should you consume during the UTMB®?
Between 60 and 90 grams per hour in total, up to 90–120g/h for trained runners combining glucose and fructose, using an isotonic drink, gels and bars, provided you have trained your digestion for this effort before the race.
Should you eat at set times during the race?
No, it is better to aim for an intake every 20 to 30 minutes in small, regular amounts rather than large, widely spaced intakes, to avoid digestive issues.
How can you train your digestive system before the UTMB®?
This is known as gut training: gradually increasing your carbohydrate intake during long runs over several weeks. Find the full protocol in our dedicated article.
Find out more
- Gut training for ultra-trail
- Energy drink for the UTMB®: how to choose?
- Energy gels and bars for the UTMB®
- Aid stations and nutrition during the UTMB®
- Preparing your race pack for the UTMB®
Photo credits: Clément Dumas.
