The format is secondary; the job is delivering carbohydrate early enough for your gut to absorb it.Stack-kit editorial
Gels, chews, and drink mix are just delivery systems. The source evidence is about carbohydrate dose, glucose-fructose transport, sodium-fluid balance, caffeine timing, and gut training. Pick the format that lets you execute those without stomach rebellion.
The comparison table
| Option | Best for | Dose | Evidence | Caveat |
|---|---|---|---|---|
| Energy gels | Running, compact carry, precise carb pulses | Maurten Gel 100 is 25 g carbs; 2-3/hour fits the source target | Source supports dual-carbohydrate fueling and Maurten's hydrogel/gut-tolerance rationale | Needs water; too many concentrated gels without fluid can backfire |
| Chews | Athletes who tolerate chewing and want slower intake | Count grams toward the same 60-90 g/hour target | Evidence is inherited from carbohydrate delivery, not a named chew trial in the source | Harder at race effort; can be sticky, slow, and easy to underdose |
| Drink mix | Cycling, triathlon bike leg, athletes carrying bottles | Maurten 320 gives 80 g/500 ml; SiS Beta Fuel 80 gives 80 g/600 ml | Source names Maurten 320 and SiS Beta Fuel 80 as practical dual-carb formats | Carbs are coupled to fluid; do not overdrink just to hit fuel |
| Electrolyte-only drink | Sodium-fluid management when carbs come from gels | PH 500 or PH 1000 at 45-60 minute intervals in the source protocol | Source supports sodium with fluid to reduce dehydration and hyponatremia risk | Not fuel; low-carb electrolyte drinks cannot replace carbohydrate intake |
| Real food | Lower intensity training or athletes with practiced tolerance | Use only if grams can be counted and practiced | Source evidence does not anchor on real-food trials; it anchors on carb throughput | Fiber, fat, protein, and chewing can tax the gut at race intensity |
Carb density is not optional
The source protocol targets 60-90 g carbohydrate per hour for 3-6 hour race-intensity events. The physiology is transporter-limited: glucose or maltodextrin alone queues at SGLT1 around 60 g/hour, while adding fructose opens GLUT5 and supports the higher combined ceiling. That is why serious endurance fuels use glucose-fructose or maltodextrin-fructose systems.
Start at 30-45 minutes, not when you feel hungry. Gut absorption has lag time. Waiting until the bonk is visible means the correction is already late.
Hydration coupling is the trap
Gels separate fuel from fluid. That is useful when aid stations are frequent or your sweat rate is low. Drink mix couples the two. That is useful on the bike, but dangerous if you force fluid to hit a carb number in cool conditions. Exercise-associated hyponatremia is usually too much plain water without enough sodium; the opposite error is under-drinking in heat and paying extra heartbeats for the same pace.
Caffeine and gut training
Caffeine is not a format; it is a dose. The source uses 3-5 mg/kg 45-60 minutes pre-start, with optional on-course caffeine later in longer events. Maurten Gel 100 CAF 100 is one source-backed way to pulse 100 mg on course, but only if you have practiced it.
Train the gut for 3-8 weeks. If long runs never exceeded 40-50 g/hour, do not debut 90 g/hour at an A-race. The source explicitly tells GI-sensitive athletes to stay lower until tolerance is built.
When to skip
Skip the upper carb range if you have fructose malabsorption, no gut-training history, or a stomach that goes sideways at race intensity. Skip sodium loading if you have hypertension, kidney disease, heart failure, prior exercise-associated hyponatremia, or physician-directed sodium restriction. Skip new products on race day, even if the label looks perfect.
Evidence notes
- Currell and Jeukendrup 2008: glucose-fructose multiple-transporter carbs improved performance versus glucose alone.
- Jeukendrup 2008, Nutrition Reviews: summarized the transporter logic behind the 90 g/hour dual-carb ceiling.
- Montain and Coyle 1992 plus the ACSM Position Stand: fluid deficit and sodium-fluid balance affect heart rate, thermoregulation, and endurance performance.
Where to go next
The full endurance protocol turns this format choice into a race-week and on-course schedule.
FAQ
Which fueling format is best?
The best format is the one that lets you hit the source protocol's 60-90 g carbohydrate per hour target without GI distress. On foot that is usually gels with water; on the bike, drink mix is often easier.
Can I use drink mix only?
Yes, if it delivers the carbohydrate and sodium you need without forcing extra fluid. If hydration needs and carb needs diverge, separate fuel from fluid.
How do I avoid race-day gut problems?
Practice for 3-8 weeks, start fueling at 30-45 minutes, use familiar products, and stay near 60 g/hour if you have not trained higher intake.
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We do not sell our own SKUs. We do not have a house brand, a premium tier, or a founder's discount. If a better evidence-backed option replaces a recommendation, the protocol changes.