Glucose Fructose Ratio in Energy Gels Explained

Glucose–fructose ratio in energy gels matters because the small intestine uses different transporters for each sugar. Glucose (and glucose polymers such as maltodextrin) rely heavily on SGLT1, which saturates near about 60 g of carbohydrate per hour in classic endurance guidance. Fructose uses GLUT5. Combining both pathways is why published targets rise from roughly 30–60 g/h toward about 90 g/h for prolonged events — when the gut is trained (Jeukendrup 2011; Jeukendrup 2014; ACSM 2016).

Being vegan does not change transporters. It changes which packets you may buy. This is educational fueling science, not a promise that any ratio guarantees a PR.

Packet counts still come from how many gels for a marathon. Format choice (pouch vs bottle) is gels vs sports drink.

The physiology in one paragraph

Exogenous carbohydrate oxidation is limited by intestinal uptake and downstream metabolism. When athletes consume only glucose-type carbohydrate, oxidation rates commonly plateau near the SGLT1-limited range discussed in sports-nutrition reviews. Adding fructose opens a second absorptive route (GLUT5), allowing higher total exogenous carbohydrate use in trained athletes during prolonged exercise — the practical ceiling often discussed around ~90 g/h, not unlimited packing of single-source gels (Jeukendrup 2014). Gut training improves tolerance and oxidation (Cox et al., 2010; Jeukendrup 2017). GI distress still rises with heat, dehydration, high concentration, and unpractised intake (de Oliveira et al., 2014).

What “ratio” means on a label

Brands advertise 2:1, 1:0.8, or “multiple transportable carbohydrates.” Translate that into four questions:

1. Does the product contain both a glucose-type carbohydrate and fructose (or sucrose, which is glucose+fructose)?
2. How many grams of total carbohydrate are in one serving?
3. Have you practised that serving rate at race intensity?
4. Is the SKU vegan-status checked? Honey gels fail regardless of ratio.

A maltodextrin-only gel can be excellent at 45–60 g/h. Stacking it to “90 g/h” often means unused carbohydrate sitting in the gut — a common nausea pattern at 28 km.

Sucrose is already a 1:1 glucose:fructose disaccharide; some products blend maltodextrin with fructose to hit a target ratio. You need the panel and a trained rate, not a chemistry degree.

| Your practised race rate | Carb system to prefer | What fails | | --- | --- | --- | | ~30–45 g/h | Almost any practised gel; single-source is fine | Buying a “90 g/h formula” you never used | | ~60 g/h | Single-source or dual; consistency wins | Jumping to 90 g/h on race morning | | ~75–90 g/h | Glucose + fructose products you gut-trained | Maltodextrin-only stack “to hit 90” | | Unknown | Start lower; build across long runs | Expo samples as physiology upgrades |

plantbaes.net’s working default for many gut-trained marathoners is 60–75 g/h, with ~90 g/h as a trained dual-source capacity.

How to pick gels without brand hype

1. Write the hourly carbohydrate target you will actually practise.
2. Divide by packet size and subtract drink-mix carbs. Catalog examples (August 2026): Maurten Gel 100 25 g, Neversecond C30 30 g, SiS Beta Fuel Gel 40 g — all manufacturer-confirmed vegan on this site, not Certified Vegan.
3. Read whether fructose or sucrose is present if your target is above ~60 g/h.
4. Check vegan status per SKU in the gels and chews catalog. Honey Stinger is honey.
5. Gut-train the exact flavour and timing (gut training guide).

Ratio myths that waste money

• “1:0.8 is magic; 2:1 is obsolete.” Formulation choices inside the same dual-transport idea.
• “Hydrogel bypasses physiology.” Delivery format may change comfort; it does not delete transporter limits.
• “More fructose is always better.” Excess unabsorbed fructose is a classic GI risk, especially with dehydration.
• “Vegan gels absorb worse.” Absorption is sugars and practice, not animal ingredients.

Dual-source gels do not fix a colon full of lentil residue. Race week still uses the ~15 g fiber/day heuristic while food carbohydrate rises to 8–12 g/kg (carb-loading guide). Build the belt in the vegan race fuel planner so bottle carbs and gel carbs do not double-count into nausea.