Did you know many endurance gels pair glucose and fructose because they use different intestinal transporters (SGLT1 and GLUT5)? That combo can raise carbohydrate oxidation versus single-source glucose — one lab protocol measured about 1.7 g/min — part of why labels often show a 2:1 mix…
Pairing glucose+fructose is like opening two lanes on the carb highway — if you’re targeting about 90 g/h, try a 2:1 mix, sip water, and “train the gut” in workouts since fructose tolerance varies. Nice explainer: https://www.mysportscience.com/post/why-multiple-transportable-carbohydrates; I’ve seen plenty land closer to 1:0.8 in long races.
Cool tidbit on SGLT1/GLUT5 — that “1.7 g/min” is usually lab-perfect; I’m closer to about 1.3–1.5 outside. What’s worked for me is micro-dosing every 10–12 min and adding a bit of sodium so glucose co-transport pulls water; if 2:1 feels rough, try nearer 1:0.8 (think Beta Fuel). @OP, have you noticed fewer gut grumbles with shorter feed intervals?
Fun angle: SGLT1 is sodium‑dependent, so if you’re pushing higher carb rates, don’t skimp on electrolytes — think of sodium as the bouncer letting glucose in. Try A/B testing a maltodextrin+fructose gel vs straight sucrose at the same effort to see which your gut likes, then scale the total per hour gradually. Solid primer here if anyone wants the lab side: https://www.mysportscience.com/post/multiple-transportable-carbohydrates.
But that “1.7 g/min” comes from multi-transportable carbs, but a small tweak: pick maltodextrin+fructose instead of straight glucose+fructose — the lower osmolality often empties faster at the same grams. And FWIW, 2:1 isn’t sacred; 1:0.8 has tested well too.