Athlete summary
In-ride carbohydrate targets are usually population bands: how long you are riding, how hard the session is, and (when justified) a gut-trained 100–120 g/h race rate. Athletes vary widely in how much exogenous glucose they can oxidise at a fixed 90 g/h dose — some around 42 g/h, others around 66 g/h.
If you have a lab peak exogenous glucose oxidation (GLUexo) report — the Birmingham FuelSync-style 13C test — Koyaro can use that number instead of a blanket 90 g/h glucose-only target. In the proof-of-concept study the personalised dose was 28 ± 11% lower than 90 g/h (mean 65 ± 10 g/h, range 49–80) while peak oxidation stayed the same and stomach fullness / RPE were lower.
| Situation | What we do |
|---|---|
| No lab GLUexo | Existing ACSM + intensity/role + Wilson bands |
| Lab GLUexo + glucose-only 90 g/h target | Personalised dose = peak ÷ 0.80 |
| Easy long ride already stepped to 60 | Leave 60 — do not raise to the personalised dose |
| Dual-source / gut-trained race 100–120 | Keep 100–120 — never cap at the glucose dose |
| Body mass / fitness only | No invented oxidation |
This is not daily carbohydrate periodization (that is a different model) and it does not replace the session burn estimate.
Literature
- Podlogar T, Cooper-Smith N, Gonzalez JT, Wallis GA. Personalised carbohydrate feeding during exercise based on exogenous glucose oxidation: a proof-of-concept study. Performance Nutrition. 2025. doi 10.1186/s44410-025-00003-9.
- University of Birmingham FuelSync (2026) — commercial protocol availability (product note, not a formula source).
- Ijaz et al., Int J Sport Nutr Exerc Metab 2024 — body size relates to exogenous glucose oxidation but does not justify inventing a dose from mass alone.