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Fueling performance research

Fueling is performance, not just health: the right carbs at the right time change outcomes.

Last updated/Feb 12, 2026, 10:18 PM

Performance Science Lab

Fueling lab

Fueling is performance, not just health: the right carbs at the right time change outcomes.

Start here

  • • Train your gut like a system: start low, build tolerance, and practice on long runs.
  • • Fueling fails happen early: under-fueling in the first hour is a common error.
  • • Most athletes under-eat on long sessions; fix that before chasing supplements.
Browse all studies in fueling

Best topic pages

Defaults you can actually run for 2–4 weeks.

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Carbohydrate fueling for long runs: a protocol you can practice

Evidence-informed protocol: Carbohydrate fueling for long runs: a protocol you can practice. Practical steps, who it helps, and what to watch out for.

Outcomes this affects

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Time to exhaustion

A lab outcome that can still guide training: it often tracks fatigue resistance.

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Time-trial performance

Practical performance outcome used in many studies: closer to racing than lab-only metrics.

Study library (reference)

Individual studies for deeper reading.

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Creatine supplementation and endurance performance: surges and sprints to win the race.

PMID 37096381 (2023): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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New Horizons in Carbohydrate Research and Application for Endurance Athletes.

PMID 36173597 (2022): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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Carbohydrate ingestion during endurance exercise improves performance in adults.

PMID 21411610 (2011): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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International society of sports nutrition position stand: nutrient timing.

PMID 28919842 (2017): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations.

PMID 31181616 (2019): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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Carbohydrate intake during exercise and performance.

PMID 15212750 (2004): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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Glucose and Fructose Hydrogel Enhances Running Performance, Exogenous Carbohydrate Oxidation, and Gastrointestinal Tolerance.

PMID 34334720 (2022): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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Carbohydrate and exercise performance: the role of multiple transportable carbohydrates.

PMID 20574242 (2010): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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The use of carbohydrates during exercise as an ergogenic aid.

PMID 23846824 (2013): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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A step towards personalized sports nutrition: carbohydrate intake during exercise.

PMID 24791914 (2014): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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Effects of Energy Gel Ingestion on Blood Glucose, Lactate, and Performance Measures During Prolonged Cycling.

PMID 31977833 (2021): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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What Should I Eat before Exercise? Pre-Exercise Nutrition and the Response to Endurance Exercise: Current Prospective and Future Directions.

PMID 33198277 (2020): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

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Performance Science Lab

Research-backed protocols and evidence grades for endurance performance — built for athletes.

Carbohydrate fueling for long runs: a protocol you can practice

Evidence-informed protocol: Carbohydrate fueling for long runs: a protocol you can practice. Practical steps, who it helps, and what to watch out for.

Creatine supplementation and endurance performance: s… (PMID 37096381)

PMID 37096381 (2023): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

New Horizons in Carbohydrate Research and Application… (PMID 36173597)

PMID 36173597 (2022): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

Carbohydrate ingestion during endurance exercise impr… (PMID 21411610)

PMID 21411610 (2011): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

International society of sports nutrition position st… (PMID 28919842)

PMID 28919842 (2017): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).