PacingCarbs

Race · Ultra

TDS nutrition plan: how much to carry, and at what rate

Over 148 km and 9,441 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.

148km
Distance
9,441m D+
Ascent

Figures from the 2026 edition. The course changes most years — check the official regulations before committing to these values.

The terrain, in numbers

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.

217km
Flat equivalent
9,629m
Descent
40%
Uphill
42%
Downhill

Demonstration

Your plan on the real course

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.

80g/h
Carbohydrate
2,240g
Total carbohydrate
76
Solid intakes
14.0L
Fluid

One solid intake every 1.95 km on average — but never at a regular interval: the spacing follows the gradient.

Target time28 h

Target time is the setting that makes the plan genuinely yours. Create an account to adjust it

148.2 km+9,441 m−9,629 mAlt. 721–2,589 m
26781653628020406080100120140
Distance (km) · elevation (m)solid intakeGradient<5%5-10%10-15%15-20%>20%

The route

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.

StartStartFinishFinish10 km
© OpenStreetMap · SRTM | © OpenTopoMap (CC-BY-SA)

The first intakes

  • +0:060.7 kmSports drink (500 mL bottle)150 mL
  • +0:101.4 kmEnergy gel (25 g of carbs)1 gel
  • +0:242.7 kmSports drink (500 mL bottle)100 mL
  • +0:323.2 kmEnergy gel (25 g of carbs)1 gel
  • +0:363.4 kmWater (500 mL flask)100 mL

and 199 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

What happens once you sign up

  1. 01

    Your target time

    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.

  2. 02

    Your products

    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.

  3. 03

    Your pack, and your watch

    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.

What this race does to your stomach

The TDS is the most technical course of the week, and that is what shifts the nutrition problem. Over much of the route your hands are on poles or on rock, not opening a wrapper: eating stops being something you slot between two strides and becomes a decision — stop now, or wait for the next runnable section, which may be forty minutes away.

The parts of the course that change the plan

  • The Passeur de Pralognan is climbed on fixed ropes, through rock: neither the place nor the moment to pull out a flask, so you need to arrive there already fuelled.
  • There is more descent than climb — 9,629 m down against 9,441 m up — and it comes on broken ground: your quads take the damage while the carbohydrate requirement does not drop by a single gram.
  • Poles stay in your hands almost throughout. Every intake means stowing them or trapping them under an arm, and that one gesture is enough to make you skip every other feed once fatigue sets in.

The total does not tell you when to eat

The same time interval covers very different distances depending on gradient. On a course with 9,441 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 times

What your pack can actually hold

The 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.

Aid stations

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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From the total to the plan

Upload the race GPX, set your target time and your products, and you get every intake at its kilometre, with the export to your watch.

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Frequently asked questions

› How many carbs per hour at TDS?

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 28 h — a mid-pack time at TDS — that comes to roughly 2,240 g of carbohydrate in total. Spreading it across gels, drink, bars and aid stations is what makes that total manageable.

› What does a 60 g/h plan look like at TDS?

Over 28 h of racing, 60 g/h comes to 1,680 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.

› And at 80 g of carbs per hour?

This is the most common rate on an ultra for a runner who has prepared their nutrition. Over 28 h, 80 g/h means 2,240 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.

› Can you sustain 100 g of carbs per hour at TDS?

Some runners manage it, after specific gut training, and almost always by leaning heavily on drink rather than solids. Over 28 h, 100 g/h comes to 2,800 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.

› How much should you drink per hour at TDS?

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.

› Does the plan account for cutoff times?

Indirectly, and the distinction matters. The nutrition plan is built on the time you are aiming for: if you aim for 38 h, it spreads the intake across 38 h. Whether that time clears the cutoffs is a different question, answered by the split-time calculator from the real elevation of the track.

› Should aid stations count towards the total?

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.

› Do these figures apply to the other distances of this event?

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.

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