Glucose-Plus-Fructose Ingestion Improves Endurance Time-Trial Performance (RCT)
Currell K, Jeukendrup AE
Evidence is still building up
Summary
A crossover RCT in trained cyclists comparing glucose-plus-fructose, glucose-only, and water (placebo) beverages during 120 min of moderate-intensity cycling (55% Wmax) followed by a time trial. At the same carbohydrate delivery rate (1.8 g/min), the glucose-plus-fructose condition completed the time trial approximately 8% faster than the glucose-only condition.
Key findings
- 1
Trained cyclists performed a time trial after 120 min of moderate-intensity cycling (glucose-plus-fructose / glucose-only / water crossover)
- 2
Carbohydrate delivery rate was matched between beverage conditions (1.8 g/min)
- 3
The glucose-plus-fructose condition was approximately 8% faster than glucose-only in the time trial
- 4
Participants were trained endurance athletes, and the result applies to prolonged (2+ hour) exercise conditions
Related research
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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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