UCI CONSENSUS SERIES
Supplementation and Nutrition in Cycling: What Does the Science Say?
The sports supplement market is currently saturated. Practically every week, a new product appears promising to boost performance or accelerate recovery. However, in high-performance sport (and in life in general), decisions should not be based on marketing, but on solid scientific evidence.
I recently had the privilege of contributing as a co-author to the new Consensus Statement on Cycling Nutrition promoted by the Union Cycliste Internationale (UCI), published in the International Journal of Sport Nutrition and Exercise Metabolism under the leadership of world-renowned experts such as Louise Burke, Asker Jeukendrup and Iñigo Mujika (you can read the full article here). In this project, we summarised the most up-to-date evidence to establish which nutritional strategies are genuinely supported by scientific research in cycling.
Before considering any supplement, the document makes one fundamental point clear: the foundations of nutrition are the most important thing. A supplement will rarely compensate for insufficient energy intake, poor hydration or inadequate carbohydrate availability. That said, once these foundations are in place, scientific literature shows that certain strategies can provide an additional performance benefit for cyclists:
The Foundations: Adequate Energy Intake and Carbohydrates
Cycling is one of the most metabolically demanding sports, and glycogen depletion is often a limiting factor. To prevent this, the principle currently guiding nutrition in cycling and sport in general is to “fuel for the work required”. In other words, carbohydrate intake should vary according to the intensity and duration of each training session.
- Day to day: Requirements range from 5–7 g/kg/day on lighter days to more than 8–10 g/kg/day during periods of intense training.
- During competition: For events lasting between 1 and 2.5 hours, recommendations range from 30–60 g/h. However, for events lasting longer than 2.5 hours, particularly at high intensity, recommendations increase to 90 g/h (or even higher amounts for adapted elite cyclists). To tolerate these quantities without gastrointestinal discomfort, it is important to train the gut beforehand and use mixtures of different types of carbohydrates (for example, glucose and fructose), which use different transporters to cross the intestine.
Protein: Essential for Recovery
Although carbohydrates are the best-known nutrient in cycling and endurance sports in general, cyclists’ protein requirements go far beyond simply increasing muscle mass. During prolonged and intense sessions, some protein is oxidised and used as an energy source. To counteract this breakdown, the UCI consensus recommends a habitual intake of 1.6–2.1 g of protein per kilogram of body weight per day. In fact, increasing protein intake to approximately 2.0–2.1 g/kg/day is particularly beneficial during periods of energy restriction aimed at refining body composition, or during sessions with low carbohydrate availability, when catabolism increases. In everyday practice, protein supplements should not replace whole foods, but they are a convenient, fast-digesting way to meet daily targets, especially after a demanding training session or on days when appetite is low following exercise.
Hydration and Electrolytes
Another important factor identified in the consensus is avoiding dehydration exceeding 2% of body weight, particularly in hot conditions, when sweat losses increase sharply. Although some cyclists tolerate higher levels of dehydration without any impact on performance, dehydration exceeding 2% generally has negative effects. And it is not just about drinking water: sodium replacement is crucial for retaining the fluids consumed, maintaining plasma volume and preventing hyponatraemia.
Supplements with Solid Evidence
Although many supplements are available on the market, only a few currently have strong evidence supporting their efficacy and safety. In fact, according to the UCI consensus, only five ergogenic supplements have this level of evidence:
Caffeine
Caffeine is the supplement with the broadest evidence base across the full range of cycling disciplines, from explosive track and BMX events to road or gravel marathons. It acts on the central nervous system, reducing the perception of effort, improving muscle fibre recruitment and enhancing concentration. The standard effective dose ranges from 3 to 6 mg per kilogram of body weight, taken approximately 45–60 minutes before the start of the effort or the decisive stages of the event.
Nitrates
When we consume nitrates (also found in products such as beetroot juice), they are converted into nitrite and subsequently into nitric oxide (NO), a powerful vasodilator that improves blood (and oxygen) delivery to the muscles and enhances efficiency. The usual recommendation is to consume approximately 300–600 mg of nitrate 2–3 hours before the event, or to maintain intake over several days leading up to competition.
Sodium Bicarbonate
During high-intensity efforts, hydrogen ions (H+) accumulate, causing acidity in the muscles. Bicarbonate increases the blood’s buffering capacity, delaying acidosis. It is particularly useful in disciplines involving high-intensity efforts, such as track cycling, cyclocross, mountain biking or explosive finishes in road racing. In general, studies use doses of 0.2–0.3 g/kg of body weight, taken 60–120 minutes before the race. Given its potential to cause gastrointestinal discomfort, split-dose protocols or controlled-release formulations are now recommended.
Beta-Alanine
When we consume beta-alanine, our body produces another compound called carnosine, which is found in the muscles. Just as bicarbonate reduces acidity in the blood, muscle carnosine is the main buffer of acidity inside the muscle cell itself. It is therefore important for high-intensity efforts and has shown benefits particularly in efforts lasting between 1 and 10 minutes (for example, on short climbs or during attacks). Unlike bicarbonate, it does not have an immediate acute effect; it requires consistent supplementation of 3.2–6.4 g/day, divided into several daily doses, for a minimum of 4–8 weeks.
Creatine
Creatine is one of the most popular supplements today. It increases muscle phosphocreatine stores, providing energy for maximal-power, short-duration efforts. Although it is highly effective for sprinters, further evidence is still needed in road cyclists and climbers. It should be used cautiously in these athletes because it is often associated with a slight increase in body weight (1–2 kg) due to water retention, which could negatively affect the power-to-weight ratio (W/kg) on climbs.
Vitamin D and Calcium
Although these compounds are not associated with improved performance, they may be advisable in certain cases for health reasons. Cycling is a sport without direct mechanical impact, which often translates into low bone mineral density, particularly in professional cyclists. Ensuring adequate calcium and vitamin D levels is important to help prevent osteopenia and stress fractures.
Conclusions
In this UCI consensus, we set out nutritional strategies to improve health and performance in cyclists. The most important message is that nutritional deficiencies should be assessed first, whole foods should be prioritised whenever possible, and only supplements supported by robust scientific studies should be selected. Furthermore, to combat so-called “inadvertent doping”, it is essential to use products endorsed by independent certification schemes that rule out cross-contamination, such as Informed Sport. Supplementation should not replace well-planned training or an optimal diet, but once these foundations are firmly in place, choosing the right aids can make a difference to performance.
References
- Burke LM, Dolan E, Gonzalez JT, Mujika I, Jeukendrup AE, Redegeld M, Martins G, Valenzuela PL, et al. UCI Sports Nutrition Project: Position Statement on Nutrition for Cycling. Int J Sport Nutr Exerc Metab. 2026. Ahead of Print. doi:10.1123/ijsnem.2026-0135
