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Does that gel do the job?
Set the job — the race or session you are fueling — then check any gel, chew, drink mix or bar against it. Job fit is the only score. What is in the product is shown as facts, and your own preferences decide what counts as clean.
1 · The job
- Above 60 g/h a single sugar type saturates its gut transporter — choose dual-source products (glucose + fructose, roughly 2:1 to 1:0.8) for anything past 60 g/h.
- Practise this intake in training 2–3 times a week for 4–6 weeks; the gut adapts, and race day is the wrong place to find out.
- Running jostles the gut — spread doses every 15–20 min rather than one big hit each hour.
- Fluid is a ceiling, not a quota: drink to thirst and never force it — finishing heavier than you started means you drank too much.
Rules for run
- First gel inside the first 40 minutes, not at the first sign of fading — you cannot catch up.
- Take the gel 100 m before the station, water at the table.
- Nothing bigger than 30–40 g at once; running shakes the gut.
- Six to eight gels is a belt; past that, plan on the course drink.
Not medical advice. Everything here is computed from the rules in the FAQ below — no black box.
2 · Check a product
Graded for this job: Run, 3.5 h, race pace, 80 g/h. The same gel grades differently on a different job.
Top 9 of 64 for this job · sorted by grade
3 · Your fuel schedule
Up to three products — a drink mix, a gel or chews, and something caffeinated works well. Salt capsules close any sodium gap; water is what is left of your fluid target.
A gel-first template for 3.5 h. Swap each placeholder for a real product below — the schedule updates as you go.
Placeholders stand in until you pick real products — or add products from step 2 instead.
Why does the glucose-to-fructose ratio matter?
Glucose is absorbed through one intestinal transporter that saturates around 60 g per hour. Fructose uses a second transporter, so a dual-source product (roughly 2:1 to 1:0.8 glucose:fructose) lets you absorb 90 g per hour or more without the surplus sitting in your gut. Below 60 g per hour the ratio barely matters.
Is a gel with a lower "health" score worse?
This tool does not score health. Mid-race fuel is designed sugar, so a Yuka-style score would fail every gel. We grade job fit — whether a product delivers the carbs you need at the rate you can absorb, without gut-irritant ingredients, in a practical number of units — and show the formulation as plain facts so you can apply your own preferences.
How many carbs per hour do I need?
Under an hour, none. Between one and two and a half hours, 30–60 g. Long races, 60–90 g. Past four hours, 90 g, and up to 120 g on the bike with a trained gut. Running tolerates less than cycling, and heat does not raise the carb target — it raises fluid and sodium.
What changes for a triathlon?
The plan follows the legs. Nothing goes in during the swim — a gel about 15 minutes before the gun is the last intake (it is counted in the shopping list). T1 and T2 are for moving, not eating. The bike carries the bottle and most of the carbs: 10 % above the base target, capped at 90 g per hour (110 with a trained gut), first bite 10–15 minutes in, last gel 10 minutes before T2, solid food only in the first three fifths of the ride and never in its last 30–45 minutes. The run takes 70 % of the base rate (80 % gut-trained), capped at 60 g per hour (80 gut-trained), as gels and chews with water from the aid stations — no bottles — from about 15 minutes in until 15–20 minutes before the line. Caffeine goes in on the last stretch of the bike so it peaks as the run starts, then mid-run, and stops near your recommended budget. Enter your own splits and the timeline follows them.
How much should I drink?
The fluid number is a ceiling, not a quota. It starts from body mass (about 650 ml an hour at 70 kg), rises with heat and humidity, drops by a fifth on an easy day, and never passes 1.2 L an hour — roughly what the gut can empty. A measured sweat rate replaces the estimate at 80 % of what you lose, so you always drink less than you sweat. Drink to thirst and never force it: over-drinking, not dehydration, causes exercise-associated hyponatremia, and it mostly catches long, slow days. Plans of 5 litres or more say so first. If you finish heavier than you started, you drank too much.
How much caffeine is too much?
The plan aims for about 3 mg per kg of body mass (4 on days of eight hours or more) and never goes past 6 mg per kg or 400 mg in a session, whichever is lower — per-kg dosing alone would let a heavy athlete reach 700 mg or more. No single dose tops 200 mg (100 mg on the run), and caffeine you take before the start comes off the budget.
How do I measure my sweat rate?
Weigh yourself nude and dry before and after a session of at least an hour, note what you drank and any urine, and the calculator converts the difference into litres per hour. One test describes one set of conditions, so repeat it in the heat.
Targets follow the same deterministic engine as the race guides (ACSM/IOC fluid ranges, Jeukendrup on multiple transportable carbohydrates, ISSN on caffeine, Baker 2017 on sweat sodium). Label facts come from the source named on each product and can change — check the pack. Not medical advice. Not affiliated with any brand.