Reference
The Science of Endurance Fueling
Every formula decision — which sugars, what ratio, how much sodium — is dictated by intestinal transporter kinetics, gastric emptying thresholds, and osmolality. This page is the citation layer: each concept below ties back to the research it comes from. New to the topic? Start with the playbook on /how-it-works.
Ready to put this into practice?
The builder shows transporter utilization, osmolality, and ratio analysis in real time as you design your mix.
Open the BuilderThe exact equations, constants, and a worked example you can check by hand against any commercial product.
How many carbs per hour, gel vs. drink, gut training, electrolytes, DIY safety — with each answer linked to the science.
Gatorade in 1965 to modern hydrogels — the research milestones that actually moved the needle.
References
The physiological claims above rest on three peer-reviewed sources. Each links out to a Google Scholar search for the full text — Scholar surfaces the journal page, the DOI, and any open-access PDFs.
- Jeukendrup, A. (2014). A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Medicine. Google Scholar →
The dose-rate framework — 30, 60, 90 g/hr by exercise duration — that the entire sports-nutrition industry now uses.
- O'Brien, W.J., Stannard, S.R., Clarke, J. & Rowlands, D.S. (2013). Fructose-Maltodextrin Ratio Governs Exogenous and Other CHO Oxidation and Performance. Medicine & Science in Sports & Exercise. Google Scholar →
Twelve-cyclist sprint-performance study (10 × 2-min maximal sprints after 2 hours of steady-state riding at 57% peak power) that established 1:0.8 glucose-to-fructose as superior to 2:1 on oxidation efficiency, power output, and GI tolerability.
- Podlogar, T. & Wallis, G.A. (2022). New horizons in carbohydrate research and application for endurance athletes. Sports Medicine. Google Scholar →
The current consolidated review of high-carb fueling — pushes the modern ceiling to ~120 g/hr, and reviews the matched-dose hydrogel literature that has not reproduced a benefit over standard 1:0.8 drinks.
The ingredients in every formula
Each ingredient gets its own deep-dive: chemistry, dose guidance, and the cheapest credible bulk source we've found.
- Maltodextrin
The glucose-polymer workhorse in almost every high-carb sports drink — same energy as dextrose, far lower osmolality, nearly tasteless.
- Fructose
The GLUT5-transported sugar that lets you push past the 60 g/hr glucose ceiling — pair with maltodextrin at ~1:0.8 for the modern dual-transporter formula.
- Cluster Dextrin (HBCD)
An ultra-low-osmolality glucose polymer engineered for the highest carb intakes — premium price, real (but situational) benefit.
- Table Salt (Sodium Chloride)
The cheapest, most-bioavailable sodium source in your kitchen — pennies per gram and chemically identical to what's in any electrolyte tab.
- Sodium Citrate
A smoother-tasting sodium source than table salt — the alkalising buffer commercial drinks use to dose sodium without the bite.
- Potassium Chloride
The cheapest, densest source of potassium for sports drinks — same form LMNT, Tailwind, and Precision Fuel use.
- Magnesium Malate
The magnesium form LMNT chose for Recharge — highest elemental-Mg fraction of any common powder, clean taste, well-tolerated.
- Magnesium Citrate
A perfectly fine alternative to magnesium malate — the form Walker 2003 used to settle the citrate-vs-oxide bioavailability question.
- Sodium Alginate
The seaweed-derived gelling agent in Maurten's hydrogel — fascinating chemistry, contested performance benefit.
- Pectin
The fruit-derived gelling agent that pairs with sodium alginate in Maurten-style hydrogels — the second half of the encapsulation chemistry.
See the science applied to real products
Each DIY teardown below walks through a specific brand's formulation choices — which ratio they chose, why, and whether the research actually supports the premium.
- DIY MaurtenDrink Mix 320
The 1:0.8 glucose-to-fructose ratio taken to its marketing extreme — plus the hydrogel evidence that's weaker than the branding implies.
- DIY Science in SportBeta Fuel Powder
The most research-forward 1:0.8 formula on the market, with a near-public recipe. The cleanest research-backed product to copy at home.
- DIY NeversecondC30 Energy Gel
An Asker Jeukendrup–led collaboration that uses 2:1 for its 30g gel — here's why the ratio changes with carb density, straight from the research lineage.
- DIY Skratch LabsSuper High-Carb Sport Drink Mix
An outlier 12:1 design that bets on HBCD's low osmolality over dual-transporter absorption — a useful counterpoint to the 1:0.8 orthodoxy.
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