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Build your own endurance fuel
Whatever you build here, train with it. Run this exact fuel in your sessions for at least two weeks before you race it — that is how your gut learns to take it at speed. Practice the fuel, not just the pace.
NOTHING NEW ON RACE DAY!
Build direction
You set the total and the split. The calculator solves the amounts, and holds them there while you pin individual sources.
Your drink
You set thisCarbohydrate sources
Orange is glucose, pink is fructose.
Electrolytes
Hydrogel
Gel-formers that stay liquid in the bottle and set in your stomach. The evidence →
What that builds
Delivers
2 : 1G : F
Transporter mix
- Carbs
- 89.9 g
- Concentration
- 12%w/v
- Osmolality
- 354hypertonic
- Energy
- 353 kcal
DIY race drink
SolvedFor one 750 mL bottle. Weigh the solids; add water to the mark.
With two sources at a fixed total and ratio, the amounts are determined — there is nothing to fine-tune. Add a third source and the sliders come alive: pin one, and the rest re-solve to hold your carbs and your split. Or switch to freehand and set every amount yourself.
Cost to make
CAD 1.18
About 11.5× cheaper than the equivalent in gels (CAD 13.61).
Send this formula to someone
A link that opens on this exact bottle, the recipe as text, or a card to post.
How to mix it
- You need a scale, a jug that holds more than 750 mL, and a whisk.
- Weigh the dry ingredients into the jug: 63 g maltodextrin, 30 g crystalline fructose, 1.3 g table salt (sodium chloride).
- Add about a third of the water (15–25 °C — cool tap water, not warm) and whisk until nothing is left on the bottom — a whisk clears lumps far faster than shaking does.
- Top up to the 750 mL line, whisk again, then pour into your bottle.
- Taste it. If it is too sweet or too salty to finish, that is a real problem and not a small one — a bottle you cannot drink is fuel you did not take. Dilute it and carry more.
Is the hydrogel worth it?
The idea is elegant: sodium alginate and high-methoxyl pectin stay liquid in your near-neutral bottle, then set to a soft gel the moment they hit stomach acid — in theory wrapping the sugar, emptying the stomach faster, and letting you carry very high carbohydrate with less distress.
The pooled evidence says no. The 2022 meta-analysis in Sports Medicine – Open came back null on all three of performance, carbohydrate oxidation and blood glucose — measured against the same drink without the gelling agents. One running trial reported the gel about 2.1% faster than a matched drink; it sits inside that pool, and the pool is still null. Even the study that imaged the gel forming in a human stomach found it gone by 60 minutes with blood glucose no different from the control. Whatever gain people feel from these drinks, the evidence points at the drink — a high, well-tolerated glucose:fructose blend — and not at the gel.
The question we are working on at Brown Family Sports is a sharper one: can a runner with a sensitive gut — a low fructose tolerance, say — use the gellers to take in more carbohydrate without the GI distress that normally caps them? If it works, the gel is not the performance ingredient itself — it is what lets that runner reach a high carbohydrate intake, and with it the well-documented gains in performance and next-day recovery that come from fuelling high. The raw materials cost pennies, so it is cheap to test — and training is where you find out whether it helps you.
Why a high carbohydrate intake aids performance and recovery →
Mix cool, and other rules
You cannot “denature” a carbohydrate by making a sports drink — sugars are heat-tolerant. The thing you can wreck is the gel. Heat, and especially heat plus acid, shortens the alginate and pectin chains and leaves you with a weaker gel.
- Mix at 30–40 °C. Cool water is ideal. Nothing here needs hot water; boiling water is the one thing to avoid.
- Beat the clumps. The usual home failure is not heat — it is “fish eyes”. Whisk the dry polymers into the dry maltodextrin first, then sprinkle that into the water while stirring, and let it hydrate 15–30 minutes.
- No acid in a hydrogel drink. Lemon, lime and citric acid can set the gel early — in the bottle — and speed the breakdown.
- Make it fresh. Mix the day you use it rather than storing a hydrogel batch for weeks.
A plain sugar-and-salt drink is far more forgiving — these rules matter once you add the polymers.
The ingredient stat sheet
What each carbohydrate does, which transporter carries it, and where it sits on the glucose–fructose axis.
The ingredient stat sheet
What each carbohydrate does, which transporter carries it, and where it sits on the glucose–fructose axis.
Maltodextrin
The professional base. A glucose polymer, so it carries a lot of glucose with barely any osmotic load — the least sweet, easiest-drinking way to raise glucose.
Dextrose
Pure glucose — the clean control. It reaches the blood a touch faster than maltodextrin, but that is not the bottleneck in endurance (the gut transporter is), and every molecule counts osmotically.
Our take: We strongly suggest maltodextrin over dextrose for any endurance event. Same glucose, but maltodextrin is a polymer: far fewer dissolved particles, so lower osmolality, less water pulled into the gut, better tolerance, and a higher carbohydrate concentration in the bottle. Dextrose barely enters the blood faster — and a high-molecular-weight glucose polymer was oxidised no faster (in one study, slower) than glucose during cycling. Keep dextrose for short, explosive efforts, post-workout glycogen refill, or as a control drink in your own testing — not as your race base.
Table sugar
Sucrose is already a 1:1 glucose-fructose blend and cheap. The middle lever — add it to move toward more fructose without honey flavour.
Maple syrup
Basically a natural liquid table sugar — mostly sucrose, so it splits to a clean ~1:1 glucose-fructose. Predictable and mild-flavoured; lower carb density than table sugar because a third of it is water. The tidy centre lever.
Coconut sugar
Mostly sucrose, so it behaves close to table sugar, plus a little potassium and a flavour. Carries inulin (a FODMAP fibre) — fine in small amounts, a GI risk at a full dose.
Honey
A natural, fructose-rich glucose-fructose mix with flavour. Already free monosaccharides (not sucrose), so it leans fructose and is osmotically heavier — the fructose knob with taste.
Crystalline fructose
Pure fructose on its own transporter — this is what lets total intake climb past ~60 g/h. Alone it is poorly tolerated; it belongs alongside glucose, never on its own.