A decade ago, 60 g/h was the gold standard. Today, the pros are pushing double that, and it’s changing how races are won. Let’s take a closer look at the UCI Sports Nutrition Project to find out how this happened.
The carb intake arms race
Modern road cycling is faster, more aggressive, and decided earlier than ever. Teams now deliberately elevate the pace from the start, forcing selections and creating fatigue long before the finale. This tactical evolution has a metabolic consequence: riders burn through glycogen stores faster, making carbohydrate availability the limiting factor in performance.
Carbohydrates are the body’s preferred fuel for high-intensity efforts. While fat stores are nearly limitless, carbs provide faster ATP resynthesis and greater oxygen efficiency. This is critical for attacks, breakaways, and sprints. When glycogen runs low, power output drops, and races are lost. The solution? More carbs, delivered smarter.
The science: How 120 g/h became possible
For years, sports scientists hit a wall: single-carb sources (like glucose or maltodextrin) maxed out at ~60 g/h oxidation. The bottleneck? The glucose transporter (SGLT1) in the intestines could only handle so much at once. But in the early 2000s, researchers discovered a workaround: multiple transportable carbohydrates.
By combining glucose + fructose (which use different absorption pathways), riders could bypass the bottleneck and absorb far more. Studies by Jentjens and Jeukendrup (2004–2006) proved that glucose-fructose blends allowed oxidation rates of 90–120 g/h with direct performance benefits in endurance tests (Currell & Jeukendrup, 2008). This wasn’t just theory; it was a game-changer for racing.
The real-world adoption followed quickly:
Pre-2010: Most riders consumed 30–60 g/h (García-Rovés et al., 1998; Pfeiffer et al., 2012).
2010–2020: 90 g/h became standard in the peloton (Muros et al., 2019).
Today: 120 g/h and above is now common on hard mountain stages, where energy demands are extreme.
The performance impact
Why does this matter? Because carbs delay fatigue in three key ways:
- Glycogen sparing: High carb intake suppresses liver glycogen depletion (Gonzalez et al., 2016), keeping energy reserves topped up.
- Blood glucose stability: Exogenous carbs maintain euglycemia, normal blood sugar.
- Oxygen efficiency: Carbs produce more ATP (units of energy) per oxygen molecule than fat, allowing riders to sustain higher power outputs in decisive moments (Lim et al., 2011).
There’s another key benefit: recovery. Carbs absorbed during exercise are available immediately post-ride, accelerating glycogen replenishment (Jeukendrup et al., 1999). In stage races, this can be the difference between bouncing back and fading away.
The catch: Tolerance and practicality
Of course, shovelling down 120 g of carbs per hour isn’t as simple as it sounds. Early attempts often led to gastrointestinal distress. But modern pros have cracked the code:
Gut training is non-negotiable: Riders gradually increase carb intake in training to adapt their digestive systems (Jeukendrup, 2017).
Form doesn’t matter much: Drinks, gels, chews or even solid foods (like rice cakes) all work as long as they’re low in fat, fibre, and protein (Hearris et al., 2022).
Not a free-for-all: While 90 g/h is well-supported, the benefits of 120 g/h+ are less clear. Some studies show no additional performance gain (Podlogar et al., 2022), but riders still use it for recovery advantages in multi-day events.
Key takeaways for competitive amateur cyclists
For competitive cyclists looking to adopt these strategies, start by mastering 60 g of carbs per hour, using a glucose + fructose blend for optimal absorption. Gradually train your gut by increasing carb intake during long training rides to build tolerance. And remember: hydration is key, pair your carbs with 500–750 ml of fluid per hour to maximise absorption and performance.
The 120 g/h carb revolution isn’t just about eating more. It’s about eating smarter. The UCI’s project proves that nutrition is no longer just fuel – it’s a strategy. And the message from the scientists and WorldTour teams is clear: whether you’re a pro or an amateur, the rewards of getting it right are undeniable.
