Recent studies question the push for 120 grams per hour of carbohydrates. Learn why master athletes should target a proven 60 to 90 gram strategy instead.
On September 9, 2026, cycling outlet Road.cc published a live blog covering Stage 17 of the Vuelta. The stage was largely flat and expected to finish in a bunch sprint, making it a fast and tactically demanding day for the riders. Matty Brennan won his fifth stage of that Vuelta after strategically using Magnus Cort’s slipstream in the final moments of the race. He passed his competitor in approximately the final 50 metres to take the victory in spectacular fashion.
The live update named several notable riders in the peloton including Brennan, Wout van Aert, and Rasmus Tiller. However, the accessible content of the report did not actually report their carbohydrate consumption or detail any specific team fueling protocols during the stage. This lack of explicit data is a common issue when sports media covers endurance events.
The broader endurance sports community is highly focused on extreme carbohydrate intake trends. Many amateur athletes read race coverage and assume the professional peloton is routinely consuming up to 120 grams per hour. The reality of evidence-based sports nutrition requires a closer look at the actual science behind these massive fueling numbers. We need to look past the hype and evaluate what clinical research actually supports.
Established sports nutrition guidance has traditionally differentiated carbohydrate intake by exercise duration and overall intensity. According to a personalized fueling framework by researcher Asker Jeukendrup, approximately 60 grams per hour is associated with efforts lasting roughly two to three hours. The guidance shifts to approximately 90 grams per hour for longer ultra-endurance events that demand a massive energy output. Reaching this higher intake requires the use of multiple transportable carbohydrates to avoid severe digestive distress. Single-source fueling strategies simply cannot process that massive volume of sugar efficiently during hard physical efforts.
Reendure consistently emphasizes the importance of translating abstract sports science into usable training habits. The Jeukendrup framework is valuable exactly because it treats carbohydrate needs as dependent on exercise duration and intensity. It also heavily weighs the athlete’s individual ability to tolerate and absorb fuel over time. It does not offer one universal number that every single runner or cyclist must blindly hit. This personalized model is a much better guide for long-term performance than continuously chasing the highest possible intake.
The rationale for combining carbohydrate sources comes down to intestinal absorption limits. Glucose and fructose use separate intestinal transport pathways in the human digestive system. This dual-pathway approach allows for a higher rate of carbohydrate oxidation than relying on a single carbohydrate source alone. Athletes cannot simply consume infinite amounts of a single sugar and expect their bodies to process it rapidly. The intestines act as a physical bottleneck when a single transport pathway becomes completely saturated with glucose.
Recent scientific reviews are now rigorously reassessing this historical upper boundary of approximately 90 grams per hour. Some contemporary research argues that highly trained endurance athletes may be able to increase exogenous and whole-body carbohydrate oxidation at intakes up to 120 grams per hour. However, the same contemporary review clearly states that intakes of 120 to 200 grams per hour lack sufficient scientific substantiation at this time. More intake does not automatically equate to better performance on race day.
The performance evidence regarding these massive doses is distinctly mixed. One dose-response analysis evaluated carbohydrate intakes ranging from zero up to 120 grams per hour across various athletic efforts. That analysis estimated that performance benefits actually peaked around 78 grams per hour for the athletes tested. The performance gains diminished when athletes pushed their intake above that specific level. Consuming extreme amounts of sugar may simply burden the digestive system without making the athlete faster.
Another indexed study directly compared an intake of 120 grams per hour against a baseline of 90 grams per hour. The researchers reported greater absorption and oxidation of ingested carbohydrate at the higher intake when the formula contained a higher fructose proportion. Crucially, the study did not report any additional glycogen-sparing benefits in the muscle tissue compared with the 90 grams per hour dose. A higher oxidation rate is interesting in a laboratory setting, but it does not guarantee a meaningful race improvement.
We must carefully examine the exact populations tested in these fueling studies before completely changing our nutritional habits. One recent indexed study evaluated the effects of different single-source carbohydrates on overall endurance performance. The researchers compared a placebo against 60 grams per hour of glucose or 60 grams per hour of fructose during sustained exercise. The athletes cycled to task failure to measure the true physical impact of the different fueling interventions.
The results showed that glucose improved time to exhaustion by approximately 25 percent versus the placebo group. The fructose intervention did not produce a statistically significant improvement versus the placebo in this specific clinical trial. However, this particular study involved only seven young recreationally active participants in a controlled laboratory setting. The incredibly small sample size and the young age of the subjects make direct extrapolation to older amateur cyclists highly uncertain.
These scientific realities directly impact how ambitious athletes aged 35 to 65 should manage their daily training and racing nutrition. The current media focus often highlights the theoretical maximums of human physiology rather than practical application. It is incredibly easy for an amateur marathoner or master cyclist to feel they are failing if they are not ingesting 120 grams of sugar every hour. This mindset ignores the complex reality of human digestion and the clear diminishing returns of extreme fueling protocols. Finding the practical balance is a central theme in our new marathon guide clarifying the evidence-based use of energy gels.
You should treat 60 to 90 grams per hour as an evidence-grounded working range for prolonged endurance cycling or running events. The upper end of this range is more appropriate when the event is exceptionally long and physically demanding. Pushing toward 90 grams requires that you have specifically practiced using multiple transportable carbohydrates in your buildup. You cannot simply double your intake of a standard glucose product without inviting severe stomach trouble on race day.
Do not treat 120 grams per hour as a new mandatory default target for your weekend long rides. The available contemporary review presents this high mark as a possible strategy for highly trained endurance athletes. The evidence supporting performance benefits above 90 grams per hour remains very limited for the rest of the athletic population. Older athletes should prioritize consistency, optimal recovery, and gastrointestinal tolerance over chasing an elite numerical target. Understanding these practical biological limits helps clarify the true gap between elite fueling needs versus recreational reality.
The physical demands of professional stage racing differ wildly from the harsh reality of amateur endurance events. Elite riders manage massive daily training loads, benefit from professional support logistics, and possess highly conditioned digestive systems. A report that elite cycling teams use an aggressive fueling strategy does not automatically prove that the same intake is optimal for ambitious amateurs. Master athletes often face slower recovery times and entirely different metabolic realities as they age.
If you are experimenting with intakes near or slightly above 90 grams per hour, your specific carbohydrate formulation is critical. Use a formula that combines glucose or maltodextrin with fructose rather than simply adding more of one single sugar. This multiple-transportable approach is the documented biological mechanism associated with higher oxidation rates. Progressively test this protocol in training to ensure your gut can actually handle the heavy carbohydrate concentration.
Begin with an hourly intake you can confidently tolerate and increase it only if gastrointestinal symptoms remain entirely absent. You should aggressively test the exact combination of drinks, gels, and bars during your most demanding training sessions. The research heavily supports the importance of carbohydrate formulation and tolerance, but it does not establish one universally validated schedule for gut training. It is also incredibly important to separate the distinct questions of carbohydrate density and overall fluid requirements.
More carbohydrate intake does not automatically mean more fluid is required in your bottles on the bike. The assembled sports science simply does not justify a single universal fluid target for all riders in all conditions. Any intelligent hydration prescription requires an individualized consideration of sweat rate, weather conditions, pace, and sodium losses. Introducing a highly concentrated nutrition plan for the very first time in competition is always a poor choice.
Ambitious veteran athletes should secure a reliable and well-tolerated 60 to 90 grams of dual-source carbohydrates per hour before worrying about the extreme fueling ceilings tested in professional laboratories.
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