How Much Carbohydrate Do Cyclists Need Per Hour? Fuelling for the Ride

How Much Carbohydrate Do Cyclists Need Per Hour? Carbohydrates are the primary fuel for high-intensity endurance exercise, making them essential for athletes aiming to optimize performance during races or intense training sessions.

This is especially true for cyclists, where sustained efforts, varied terrains, and the need for quick bursts of power demand consistent energy input. However, the amount of carbohydrate required per hour depends on exercise duration, intensity, and individual tolerance.

It's not just about fuelling; it's about fuelling smart. This is an article specifically focussing on cycling as a sport. Andy Blow from Precision Fuel & Hydration has written several in depth articles regarding this subject. We highly recommend you check out Andy’s article for detailed insights into this topic, including visual guides and practical tips for carb intake during ultra-endurance events.

Key Takeaways

Why Carbohydrates Matter for Cyclists: The Glycogen Connection

During intense cycling, glycogen—stored carbohydrate in muscles and the liver—is the primary energy source. Glycogen is formed of chains of thousands of glucose molecules, acting like your "current/checking bank account for energy," as opposed to fat, which is more like your "savings for a rainy day." Glycogen stores are finite and typically deplete after 90-120 minutes of hard riding, which can significantly impact performance. This is where exogenous fuelling comes in. Cyclists rely on carbohydrate sources like energy gels, drinks, or bars to maintain energy levels during prolonged rides. These provide "extra cash" for energy expenditure while racing or training at high intensities. Relying solely on fat to fuel high-intensity exercise simply doesn't allow for the levels of output needed for racing or pushing hard.

Carbohydrate Intake Guidelines by Duration for Cyclists

A visual guide to how much carbohydrate to take in per hour

*When ingesting more than 60 grams of carbohydrate per hour there can be advantages to using a 2:1 glucose/fructose mixture

Here’s a breakdown of recommended carbohydrate intake based on exercise duration, tailored for cyclists:

1. Less than 1 Hour:
   • Cyclists starting well-fuelled generally don’t need additional carbs for activities under an hour. This is suitable for short, intense criteriums or hill climb repeats. As the provided text highlights, athletes who are starting exercise with robust glycogen stores typically don’t need to worry about ingesting carbohydrates during activities lasting less than an hour.
   • Cyclist-Specific Tip: A quick swig of an energy drink during a short, sharp climb can provide a mental and physical boost.
   • For short, high-intensity efforts (45–60 minutes), a small amount of carbohydrate or even a carb mouth rinse may enhance performance, especially during sprint intervals or intense group rides. This is because when exercise is of slightly longer duration (45-60 minutes) and of an "all-out" intensity then there is some evidence that performance may benefit from a small amount of carbohydrate ingestion or a carb mouth rinse, which might be more convenient during intensive racing when swallowing is hard.
2. 1–2 Hours:
   • Consuming 30–60 grams of carbohydrates per hour significantly benefits performance.
   • This can be achieved through 500ml–1L of isotonic energy drink or 1-2 energy gels.
   • Cyclist-Specific Tip: Consider the terrain. Uphill sections may require the higher end of this range, while flatter sections might allow for slightly less. Practice consuming fuel while riding in different positions to avoid discomfort. For bouts lasting between 1-2 hours, it can be beneficial to consume ~30-60 grams of simple carbs per hour. This equates to about 500ml-1l (16-32oz) of a ‘standard’ isotonic (~6% carb) energy drink, or about 1-2 standard energy gels per hour.
3. More than 2 Hours:
   • Higher intake levels of 60–90 grams per hour are recommended.
   • Elite cyclists often consume even more during long races like Grand Tour stages or long-distance cycling events. We’re routinely impressed with the high levels of carb intake reported hour after hour by the Tour De France riders and IRONMAN winners.
   • Using multiple transportable carbohydrates (e.g., glucose-fructose blends) can improve absorption and reduce gastrointestinal distress. Significantly, this rate of carb consumption is where there may be some benefit in paying attention to the source of carbohydrate ingested.
   • Cyclist-Specific Tip: For long rides, vary your carb sources to prevent taste fatigue. Alternate between gels, chews, and real food like bananas, rice cakes, or even small sandwiches.
   • Cyclist-Specific Tip: Plan your fuel stops strategically based on terrain and accessibility. Use downhills to consume larger items or adjust gear.

Body Size and Carb Intake: Grams Per Hour vs. Grams Per Kilogram

Interestingly, body size has minimal influence on carbohydrate absorption rates. All the recommended carbohydrate intakes during exercise we’ve discussed so far are expressed in simple grams per hour, not grams per kilogram of bodyweight per hour. The reason for this is that body mass isn’t a hugely relevant factor because the amount of carbohydrate our muscles can use is primarily dictated by the rate at which sugars can be absorbed through our gastrointestinal tract. Research shows that athletes of varying sizes absorb carbs at similar rates, making grams per hour a universal guideline rather than grams per kilogram of body weight. As such, the ballpark advice is essentially the same for a 50kg (110lbs) athlete as it is for a 90kg (198lbs) athlete because, for both, the limiting factor in the process is how much carbohydrate they can move through the gut into their bloodstream per minute - and that is very similar no matter their total body size.

Practical Examples: What Does 30, 60, or 90 Grams Look Like for Cyclists?

Cyclists can achieve their carbohydrate targets through various options:

• 30g/hour: One standard energy gel or ~500ml of isotonic drink.
• 60g/hour: Two gels or ~1L of isotonic drink.
• 90g/hour: Three gels or a combination of chews and drinks.
• Cyclist-Specific Tip: Consider your bike's storage options. Frame-mounted bags or jersey pockets can carry gels, chews, and small snacks. Ensure you can easily access and consume your fuel while riding.

Here’s a table with the typical carb content you’d expect to find in a few common energy products:

*Always check the packaging on products as different brands contain different types and amounts of carbohydrates.

Training the Gut for Cycling: Adaptation is Key

For cyclists aiming to consume higher carb doses (above ~60g/hour), gradual adaptation is key. Training the gut over several weeks helps improve tolerance and reduces gastrointestinal distress during long events. Practice your fuelling strategy during training rides to ensure it works on race day. This is an area where the research is currently playing catch-up with what elite athletes appear to have been doing for some time, and so it probably represents the next area in which our collective understanding will continue to improve. In the meantime, if you’re seeking to increase your carb intake, gradually tweaking your consumption upwards from whatever your current tolerable limit is during one or two hard sessions per week over a period of 4-6 weeks seems to be the recommended approach to training your gut from those who have tried it successfully in the field.

Beyond Carbs: Hydration and Electrolytes

While carbohydrates are crucial, remember the importance of hydration and electrolyte balance. Combine your carb intake with appropriate fluid and electrolyte replacement to prevent dehydration and cramping. Consider using electrolyte tablets or drinks, especially in hot weather.

Experiment and Personalise

Ultimately, the best carbohydrate intake strategy is one that's tailored to your individual needs and preferences. Experiment with different fuel sources, intake rates, and timing strategies during training to find what works best for you. Keep a record of your fuelling during rides and races to identify patterns and adjust as needed.

Frequently Asked Questions (FAQs)

Q: Why is carbohydrate so important for cyclists?
A: Carbohydrates are the primary fuel source for high-intensity endurance exercise. Cyclists need carbs to maintain energy levels, especially during long rides or races.

Q: How do I know how much carbohydrate I need per hour?
A: The amount depends on the duration and intensity of your ride. Generally, for rides under an hour, you may not need additional carbs. For 1-2 hours, aim for 30-60 grams per hour, and for rides over 2 hours, aim for 60-90 grams per hour.

Q: What are some good sources of carbohydrates for cyclists?
A: Energy gels, drinks, chews, bananas, rice cakes, and even small sandwiches are all viable options. Experiment to find what works best for you.

Q: How do I "train my gut" to tolerate more carbohydrates?
A: Gradually increase your carbohydrate intake during training rides over several weeks. This helps your gut adapt and reduces the risk of gastrointestinal distress.

Q: Does body size affect carbohydrate requirements?
A: Body size has minimal influence on carbohydrate absorption rates. Focus on grams per hour rather than grams per kilogram of body weight.

Q: What about hydration and electrolytes?
A: Hydration and electrolyte balance are also crucial. Combine your carb intake with appropriate fluid and electrolyte replacement to prevent dehydration and cramping.

Q: Can I consume too many carbohydrates?
A: Yes, consuming too many carbohydrates can lead to gastrointestinal distress. Start with lower amounts and gradually increase as tolerated.

Q: Should I only use sports-specific fuel products, or can I eat real food?
A: Both sports-specific products and real food can be effective. The key is to choose options that are easily digestible and practical for your cycling activities.

Q: How often should I practice my fuelling strategy?
A: Practice your fuelling strategy regularly during training rides, especially before important races or events.

Q: Where can I learn more about personalized fuelling strategies?
A: Check out Andy Blow's article and accompanying video, which includes tools like the Fuel & Hydration Planner to help athletes calculate their personalized nutrition needs.

Explore More

For detailed insights into this topic, including visual guides and practical tips for carb intake during ultra-endurance events, check out Andy Blow's article and accompanying video. The article also includes tools like the Fuel & Hydration Planner to help athletes calculate their personalised nutrition needs. This is especially useful for cyclists preparing for multi-day events or particularly challenging routes, like our Tour of the Swiss Alps and our Dolomites trip.

If you wish to talk to us about this or any of our tours, please feel free to call us on +44 7442798257, or email us at info@portvelo.co.uk