Race · Ultra
Over 174 km and 10,195 m of ascent, the total you need to take in does not follow from the distance but from the hours you spend on your feet. Set your target time and your carb rate: the figures below are the ones you would work out by hand, faster.
Figures from the 2026 edition. The course changes most years — check the official regulations before committing to these values.
Computed from the official track, not from the advertised figures. The flat-equivalent distance translates the ascent into the unit you already work in: the real effort of the race, expressed in kilometres of flat ground.
Demonstration
The engine is running here on the event's official track, not on an average. Move the carb rate: the intakes tighten or spread out along the profile, exactly as they will on race day.
One solid intake every 1.89 km on average — but never at a regular interval: the spacing follows the gradient.
Target time is the setting that makes the plan genuinely yours. Create an account to adjust it
The official course, drawn from the same GPX file as the profile and the intakes. To scale: what the profile flattens into a line, the route puts back into its geography.
Zoom in for the detail of the course. The scroll wheel does not zoom, so the map never holds on to your scrolling as you pass.
and 243 more intakes — solids and hydration sips alike — each placed on the terrain.
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This demonstration is computed on generic products — a gel at 25 g, a drink at 40 g/L. The planner works from your actual products and their exact values.
Three steps
The one setting locked here. It drives everything else: at 26 h or at 44 h on this course, neither the number of intakes nor their spacing is the same.
Your gels, bars and drinks — picked by brand from the catalogue or entered by hand. The plan works from their real values, not from the averages used in this demonstration.
You declare what you are carrying: the plan tells you what time each stock runs out, and exports as a GPX with one waypoint per intake.
UTMB is run largely at night and at altitude, across two nights for most of the field. That shifts the problem: over those durations the limit stops being the energy requirement and becomes your stomach's ability to keep accepting food, hour after hour, as the temperature drops and the appetite goes.
The same time interval covers very different distances depending on gradient. On a course with 10,195 m of ascent, a "gel every 5 km" plan arrives too late uphill and too early downhill. To know what hour and what kilometre you will be at, start from your split times.
Work out my split timesThe total above is a target, not a load. Part of it comes from aid stations, the rest you carry. The planner starts from what you are really taking — gels, bars, bottles, refills — and tells you what time each one runs out, instead of promising an intake your pack cannot deliver.
The official aid stations and their cutoff times are set out in the organiser's regulations, which are authoritative and change from year to year. The plan's job is not to copy them but to tell you what you still have to carry between two of them.
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Between 70 and 100 g/h for most runners, bearing in mind that over a race of this length the limit stops being the energy requirement and becomes digestive tolerance. At 80 g/h over 34 h — a mid-pack time at UTMB — that comes to roughly 2,720 g of carbohydrate in total. Spreading it across gels, drink, bars and aid stations is what makes that total manageable.
Over 34 h of racing, 60 g/h comes to 2,040 g of carbohydrate. It is a conservative rate, appropriate if you have never trained your gut for racing or if your goal is simply to finish. The risk is not immediate: it shows up in the closing hours, when the accumulated deficit is paid for in lost pace. Set the slider above to 60 to see the total and its product equivalent.
This is the most common rate on an ultra for a runner who has prepared their nutrition. Over 34 h, 80 g/h means 2,720 g. From this level upwards a glucose-fructose blend absorbs better than a single sugar: past roughly 60 g/h the glucose transporter saturates, and fructose takes a different route. Most modern sports products are formulated in that ratio.
Some runners manage it, after specific gut training, and almost always by leaning heavily on drink rather than solids. Over 34 h, 100 g/h comes to 3,400 g. Race day is not the time to test it: a high intake attempted without preparation ends in digestive trouble, which costs far more than the grams gained.
From 400 to 800 mL per hour depending on heat and how much you sweat. Volume does not follow from carbohydrate: at the same rate, running on gels and water or on a concentrated drink changes how much you drink twofold. That is why the tool treats hydration as a separate target, with its own curve.
Indirectly, and the distinction matters. The nutrition plan is built on the time you are aiming for: if you aim for 44 h, it spreads the intake across 44 h. Whether that time clears the cutoffs is a different question, answered by the split-time calculator from the real elevation of the track.
Yes, and this is where hand-made plans most often go wrong. What you take at an aid station counts towards your hourly intake exactly like your own gels. That is the point of starting from the total: it tells you how much you still have to carry once you subtract what you plan to take on the way.
The method does, the totals do not: they depend on your duration, not on the name of the race. Set the time slider to your goal for the distance concerned and the arithmetic still holds. The same is true of any other ultra.
