Fueling for Performance: How Cyclists Can Train Their Gut to Handle 120g of Carbohydrates per Hour

Last Updated on 21 August 2026:

Consuming 120g of carbohydrates per hour on the bike would once have sounded extreme, but high carbohydrate intakes have become increasingly common in endurance cycling where athletes need to sustain performance for many hours.

The challenge is that simply deciding to eat more does not mean your digestive system will tolerate it. Large amounts of carbohydrate can cause bloating, nausea and other gastrointestinal problems if your gut is not accustomed to processing that much fuel during exercise.

That is where gut training comes in. By gradually increasing carbohydrate intake during training, cyclists can practise both the practical side of fuelling and their tolerance to larger amounts of food and drink while riding.

In this guide, I’ll explain why cyclists may benefit from higher carbohydrate intakes, what is involved in training your gut, and how to progressively practise your fuelling strategy before relying on it during an important event.

Discussed in this blog:

• Introduction to Carbohydrate Intake in Cycling
  • The significance of carbohydrate consumption for cyclists.
  • Why targeting 120 grams per hour?
• The Science Behind 120 Grams
  • Exploring research on carbohydrate processing during endurance sports.
  • Benefits of high carbohydrate intake for energy and performance.
• Training the Gut for High Carbohydrate Intake
  • Strategies for gradually increasing carbohydrate absorption.
  • Scientific studies supporting these methods.
• Practical Tips for Gut Adaptation
  • Step-by-step guide for increasing carbohydrate intake.
  • Importance of hydration and carbohydrate variety.
• Application for Cyclists
  • Insights into how Tour de France cyclists manage nutrition.
  • Examples from pro cycling.
• Relevance for Amateur Cyclists in Gran Fondos and Sportives
  • Adapting these strategies for long-distance amateur events.
  • The importance of nutrition in enhancing amateur cycling experiences.
• Conclusion
  • Summarizing the importance of carbohydrate intake in cycling.
  • Encouraging a personalized approach to nutrition in cycling.
• References
  • List of scientific studies and articles referenced.

Why 120g Carbohydrates per Hour?

First, let’s address why consuming 120 grams of carbohydrates per hour is a goal for many professional cyclists. During intense exercise, like in the Tour de France, the body primarily uses glycogen, a form of carbohydrate stored in the muscles, for energy. However, these glycogen stores are limited. To maintain energy levels and prevent fatigue, it’s essential to replenish these stores by consuming carbohydrates during exercise.

Recent studies, including one published in the “Journal of Applied Physiology” (Jeukendrup, 2017), suggest that the body can process and utilize up to 90-120 grams of carbohydrates per hour during prolonged endurance exercise. This is a significant increase from the previously recommended 60 grams, highlighting the evolving understanding of sports nutrition.

Adapting the Gut for 120g Carbohydrates Per Hour Intake

Adapting your gut to handle such a high intake of carbohydrates is not an overnight process. It requires a strategic approach that gradually increases carbohydrate intake during training. This adaptation allows the body to improve its ability to absorb and oxidize carbohydrates efficiently.

A study by Cox et al. (2010) in the “Journal of Science and Medicine in Sport” demonstrated that a gradual increase in carbohydrate consumption during training sessions significantly improved gut tolerance and carbohydrate oxidation rates.

Practical Strategies for Gut Adaptation for 120g Carbohydrates Per Hour

1. Gradual Increase: Start by adding an extra 10-20 grams of carbohydrates per hour to your current intake during long rides. Slowly increase this amount over several weeks.
2. Carbohydrate Variety: Use different types of carbohydrates, like glucose, fructose, and maltodextrin. A study in the “European Journal of Sport Science” (Wallis et al., 2005) found that consuming multiple types of carbohydrates can increase oxidation rates and overall carbohydrate absorption.
3. Hydration Balance: Stay hydrated, but be mindful of fluid intake. Overhydration can dilute stomach contents and slow down carbohydrate absorption, as discussed in a study by Smith et al. (2013) in “Sports Medicine.”
4. Real-World Practice: Incorporate these strategies into your regular training rides, replicating race conditions as much as possible. Remember, digestion can be different under stress or at high altitudes, as often experienced in events.
5. Listen to Your Body: Pay attention to how your body reacts. Signs of gastrointestinal distress can indicate that you need to adjust your approach.

Why 120g Carbohydrates Per Hour Matters for Cyclists

For cyclists, especially those tackling events like the Tour de France or other endurance races, mastering carbohydrate intake can be a game-changer. It can mean the difference between hitting the wall and powering through the final stages of a race.

In the professional cycling world, athletes like Chris Froome and Geraint Thomas are known for their meticulous attention to nutrition. Their ability to maintain a high energy output over several hours is partially attributed to their optimised nutrition strategies, including effective carbohydrate consumption.

Implications for 120g Carbohydrates Per Hour for Amateur Cyclists in Gran Fondo’s and Sportive’s

While the focus on carbohydrate intake is often highlighted in the context of professional cyclists, it’s equally important for amateur cyclists, especially those participating in challenging events like Gran Fondos and Sportives. These long-distance, mass-participation events demand a high level of endurance, often resembling the stages of professional races like the Tour de France, albeit at a different level.

For amateur cyclists, mastering carbohydrate intake is not just about enhancing performance; it’s also crucial for maintaining energy levels, preventing bonking (sudden fatigue due to glycogen depletion), and enjoying the ride. A study in the “International Journal of Sports Nutrition and Exercise Metabolism” (Wright et al., 2017) found that amateur cyclists often underestimate their carbohydrate needs during long rides, leading to decreased performance and increased fatigue.

Adapting the gut to process higher amounts of carbohydrates can also help with recovery, a key aspect for amateurs who might not have the same level of fitness as professionals. Efficient carbohydrate consumption during the ride means less muscle damage and a quicker recovery post-event, as indicated by research in the “Journal of Applied Physiology” (Betts et al., 2011).

For amateurs tackling their first Gran Fondo or Sportive, or looking to improve their performance in these events, starting to train the gut to handle more carbohydrates can make a significant difference. Not only does it help in sustaining energy over long distances, but it also enhances overall riding experience, making these challenging events more enjoyable and rewarding.

Summary

Being able to tolerate 120g of carbohydrates per hour is not something most cyclists should expect to achieve overnight, nor does every ride require that much fuel.

The important principle is to match your carbohydrate intake to the demands of your training and events, and practise higher intakes gradually rather than experimenting for the first time on race day.

Long training rides provide an ideal opportunity to refine the amount, timing and type of carbohydrate you consume while learning how your digestive system responds. Just like pacing or fitness, your fuelling strategy is something that can be trained and improved.

If you are preparing for a Gran Fondo, ultra-endurance event or another demanding cycling challenge and would like help integrating your fuelling strategy into a personalised training plan, book a free consultation.

References

1. Jeukendrup, A. E. (2017). Journal of Applied Physiology.
2. Cox, G. R., et al. (2010). Journal of Science and Medicine in Sport.
3. Wallis, G. A., et al. (2005). European Journal of Sport Science.
4. Smith, H. R., et al. (2013). Sports Medicine.
5. Wright, D. A., et al. (2017). International Journal of Sports Nutrition and Exercise Metabolism.
6. Betts, J. A., et al. (2011). Journal of Applied Physiology.