A step towards personalized sports nutrition: carbohydrate intake during exercise.
Level 5 - mechanism / opinion, no new human data
Narrative review presenting expert guidelines without systematic review methodology
PubMed 24791914 · doi:10.1007/s40279-014-0148-z
What was done
This narrative review synthesized evidence on carbohydrate metabolism during exercise to propose updated, personalized guidelines for intra-exercise carbohydrate intake tailored to exercise duration, intensity, and carbohydrate type.
What was found
For exercise lasting approximately 1 hour, a carbohydrate mouth rinse or small amounts of carbohydrate confer performance benefits. For exercise lasting 2–3 hours, a single carbohydrate source can be oxidized at rates up to approximately 60 g/h (recommended intake ~60 g/h). For ultra-endurance events, intake up to approximately 90 g/h is recommended using multiple transportable carbohydrates to enable high oxidation rates and prevent intestinal accumulation. Recommended carbohydrates may be liquid, semisolid, or solid. Intake recommendations are independent of body weight and training status, but require downward adjustment when absolute exercise intensity is low.
Why it matters
This paper provides a tiered, physiology-based framework for endurance fueling that aligns intake targets with exercise duration and intestinal transport capacity.
Limits
The abstract describes a narrative guideline paper and does not provide primary experimental data, participant numbers, or systematic search and synthesis methodology.
Cited by
- supports Scientific data indicate that consuming 60 to 100 grams (specifically 80 to 100 grams) of carbohydrates per hour during prolonged exercise maximizes endurance performance.