Fructose-Glucose Composite Carbohydrates and Endurance Performance: A Critical Review
Rowlands DS, Houltham S, Musa-Veloso K, Brown F, Paulionis L, Bailey D
Evidence is still building up
Summary
A critical review examining how fructose:glucose (or maltodextrin) composite carbohydrate ingestion affects exogenous carbohydrate oxidation, gastrointestinal comfort, and endurance performance compared to single-source carbohydrates. Relative to isocaloric glucose alone, 0.5-1.0:1-ratio fructose:glucose beverages (1.3-2.4 g/min) improved mean power output by 1-9%. Single-carbohydrate oxidation caps around 60 g/h, but composite ingestion can raise oxidation to roughly 90-105 g/h by engaging separate intestinal transporters.
Key findings
- 1
0.5-1.0:1-ratio fructose:glucose beverages (1.3-2.4 g/min) improved mean power by 1-9% versus isocaloric glucose alone
- 2
Single-carbohydrate (glucose-only) exogenous oxidation caps at roughly 60 g/h
- 3
Fructose-plus-glucose ingestion can raise oxidation to approximately 90-105 g/h by using separate intestinal transporters for each sugar
- 4
The evidence base is largely drawn from prolonged (2+ hour) endurance exercise studies
Related research
Glucose-Plus-Fructose Ingestion Improves Endurance Time-Trial Performance (RCT)
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Carbohydrate periodization and its effects on training adaptation and body composition: a systematic review
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Articles featuring this study
- Explainer
Does the Fructose-Glucose Syrup in Sports Drinks Help During Exercise?
Glucose and fructose are absorbed via separate intestinal transporters, so combining them lets the body use more carbohydrate faster than a single sugar source alone. A single carbohydrate's utilization rate (oxidation) caps at roughly 60 g/hour, while a glucose-fructose mix can push this to around 90-105 g/hour. Most of this evidence, however, comes from prolonged endurance exercise lasting over 2 hours, and doesn't necessarily transfer directly to a shorter resistance-training session.
Shingo Yoshizaki
- Research vs Bro-science
"The Fructose-Glucose Syrup in Sports Drinks Boosts Athletic Performance" — Is It True? Marketing vs. Research
Sports drink packaging often implies 'improved athletic performance.' Does the fructose-glucose syrup (a glucose + fructose blend) in these drinks actually boost performance — and under what specific exercise conditions has this been demonstrated? We check the claim against the actual scope of the evidence.
Shingo Yoshizaki
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