Endurance fueling · Brown Family Sports
Train the gut. Rehearse the plan.
It builds your race-day fueling plan out of things already in your kitchen — table sugar, maltodextrin, table salt — and tells you what to mix, how much to carry, and when to drink it.
Then it writes the part almost nobody does: a week-by-week gut-training block that takes you from what your stomach handles today to what the plan asks for on race morning. The gut adapts to what you feed it, repeatedly, over weeks. That adaptation is the product.
Sixteen ingredients in the catalogue, every one of them something you can buy as itself. No proprietary blend.
01
Field studies of marathon and ultra fields keep finding intakes well under the 60–90 g of carbohydrate an hour that the work demands. The wall at 32 km gets blamed on fitness or on pacing. Often it was an empty tank, and the split chart shows it.
02
A new gel from the expo bag, a sports drink at an unknown concentration handed over an aid-station table, double the caffeine because it is the big one. The gut has never seen any of it at race pace. It objects at the worst possible moment.
03
Carbohydrate absorption is trainable. Feed the gut more, regularly, for a few weeks and it moves more — transporter density and gastric emptying both shift. That takes weeks, not days, which is why the plan and the training block have to be the same document.
Four claims. Each one is checkable inside the app.
Other apps let you record that your stomach hurt. This one writes a progressive block of sessions that moves you from what you tolerate now to what race day needs — and rewrites next week based on what your gut actually did in the last one. Tolerated it clean, the target goes up. Struggled, it holds or backs off.
Tap any figure in a plan and you get the formula, the inputs it ran on, and the study behind it, with an evidence grade attached. Carbohydrate rate is well studied. Sodium is argued about. Where the evidence is thin the app says so instead of rounding the uncertainty away.
Real glucose-to-fructose algebra so you clear more than one transporter can carry, real osmolality arithmetic so the drink empties from your stomach instead of sitting in it, and quantities you can actually measure with a kitchen spoon. Ingredient cost comes in under a tenth of what the same carbohydrate costs as gels.
It will not plan a race carbohydrate rate above what you have proven in training, however keen you are. It will not tell anyone to drink more than they sweat. Caffeine is capped by body mass and by what you are used to. The safety clamps are in the engine, not in a disclaimer.
This is an illustration of the shape of an answer, not a prescription. Your plan is built from your mass, your sweat rate, your caffeine habit and what you have already proven you tolerate — so your numbers will differ, sometimes a lot.
Inputs
Plan
| Target | Per hour | Why |
|---|---|---|
| Carbohydrate | 75 g/h | Inside the 60–90 g/h band, at a 2:1 glucose-to-fructose ratio |
| Fluid | 720 mL/h | Estimated sweat rate for this mass, pace and heat — never more than that |
| Sodium | 650 mg/h | Replaces a moderate share of sweat losses over a 3–4 hour effort |
What that means in the kitchen
75 g of carbohydrate in 720 mL would be a syrup that sits in the stomach, so the hour gets split rather than served as one bottle: a 250 mL concentrate holding 50 g of table sugar and 26 g of maltodextrin, drunk with 470 mL of water carrying 1.7 g of table salt.
Ingredients for that hour cost about CAD 0.45. The same carbohydrate and sodium bought as gels and electrolyte tablets is nearer CAD 12.
Start with your next race and the weeks you have left. You get the plan, the mixing instructions, and the sessions that make your gut ready for it.
What this is not: NOTHING NEW ON RACE DAY gives general information about endurance fueling. It is not medical or dietetic advice, and it cannot account for a condition it has not been told about. If you have a health problem, are pregnant, or take medication, speak to a clinician before you change what you eat and drink around exercise.
