How many carbohydrates per hour during a marathon and other endurance sports?
In marathons, ultrarunning, and other endurance sports, the amount of carbohydrates consumed per hour can significantly affect how well energy lasts until the end of the performance. For many runners and cyclists, a good target is about 60–90 grams of carbohydrates per hour, but at the elite level, amounts can exceed 100 grams per hour.
Our sponsored ultrarunner Juha Jumisko has now systematically started aiming for at least 90g per hour, primarily using Nduranz 90 sports drink. Juha placed fifth in the 8h category of the Mustavuori Uphill Challenge, and his next challenge is NUTS Karhunkierros 166km. We will later share Juha's energy plan for Karhunkierros. It is based on Nduranz sports drink and 45 gels.
In recent years, fueling in endurance sports has changed a lot. Whereas before, people often talked about 30–60 grams of carbohydrates per hour, nowadays, in targeted marathon running, cycling, and triathlon, 60–90 g/h or higher amounts are increasingly used.
The examples of elite marathoners have brought the topic even more to the forefront. At the London Marathon, Sabastian Sawe reportedly consumed about 115 grams of carbohydrates per hour. Other top-level runners have also used very precisely planned fueling strategies.
But what should an ordinary runner, gravel cyclist, or other endurance athlete think about this?
Does everyone need to fuel over 100 g/h?
The short answer: no.
But many would benefit from more systematic fueling. I myself only realized after a long break that I had been taking in far too little energy in my own ultrarunning races.
In cycling, carbohydrates can be consumed with fewer stomach problems in race situations, even up to 120-150g per hour, because there is no impact of running. We will later make a similar article more from a cycling perspective.
Why are carbohydrates important in marathons and endurance sports?
Carbohydrates are the most important fuel for high-intensity endurance sports. As the pace increases, the body uses more and more carbohydrates as an energy source.
There is enough fat in the body for a long time, but using fat for energy is slower. Carbohydrates, on the other hand, are quickly available energy, and therefore they are especially important when the performance is hard, long, or both.
In practice, this is evident, for example, in a marathon, a long trail run, a gravel ride, or a cycling race. If there is not enough energy, the pace easily starts to fade towards the end.
Typical signs of insufficient fueling include:
- a clear drop in pace towards the end of the performance
- a heavy and empty feeling
- decreased concentration
- strong cravings for sweets after the performance
- a feeling that "the legs are giving out," even if breathing is not at its maximum
Of course, not all fading is due to energy. But if the same pattern repeats in long runs or races, it's worth taking a closer look at fueling.
How many carbohydrates per hour should you consume?
For most endurance athletes, a good target is about 60–90 grams of carbohydrates per hour. However, this does not mean that everyone should start immediately with 90 grams.
The appropriate amount depends on, among other things, the duration and intensity of the performance, how accustomed your stomach is, the sport, and how much energy you have practiced consuming during the performance.
| Performance or goal | Suitable carbohydrate amount |
|---|---|
| Light long run | 30–60 g/h |
| Marathon or hard long training | 60–90 g/h |
| Goal-oriented race performance | 75–90 g/h |
| Very high-intensity endurance race | 90 g/h or more |
| Elite-level precisely practiced fueling | 100–120 g/h |
If you haven't fueled much before, 60 g/h can already be a big step forward. If you are an experienced endurance athlete and your stomach handles it well, 75–90 g/h can be a good target for tougher performances.
Amounts over 90 g/h can work, but they should not be introduced directly on race day.
Why do elite marathoners fuel over 100g/h?
Elite marathoners run extremely hard. When a marathon is run at a pace of about two hours, energy consumption is enormous, and the intensity remains very high throughout.
In such a performance, the availability of carbohydrates can affect how well the pace is maintained until the end. When enough carbohydrates are consumed during the performance, the body can use more quickly available energy.
High carbohydrate intake can also help spare the body's own glycogen stores. Glycogen refers to carbohydrates stored in muscles and the liver. When these stores decrease too much, performance deteriorates rapidly.
This doesn't mean that over 100 g/h is automatically better for everyone. For elite athletes, fueling is a precisely planned and practiced part of the overall strategy. They don't just decide to take more gels on race day.
Is 90–120 g/h necessary for an ordinary runner?
For most ordinary runners, 90–120 g/h is not the primary goal.
It's much more sensible to ask:
Am I currently getting enough energy during my performance?
If you're only getting 20–30 g/h of carbohydrates during a long run or marathon, jumping straight to 100 grams might be too much. In that case, a better approach is to gradually increase the amount.
For example, like this:
- Start at 40–50 g/h
- Increase to 60 g/h
- Test 75 g/h on longer or harder runs
- Try 90 g/h if your stomach handles it and performance intensity requires it
For many recreational athletes, even 60–75 g/h can significantly improve performance if previous fueling has been low.
Why is gut training important?
Fueling is not just about choosing a product. It's a skill that needs to be practiced.
In running, stomach problems are common because the impact, high intensity, and redirection of blood flow to working muscles can make energy absorption difficult. The same amount of carbohydrates that works well for cycling may not feel as easy when running.
That's why we talk about gut training.
In practice, it means accustoming your body to receive energy during performance. This is done during training, not on race day.
A good way to practice:
- take energy with you on long runs
- start with a moderate amount
- use the same product multiple times
- gradually increase the amount
- test drinks, gels, and energy chews in different combinations
- record what works and what doesn't
If the goal is a marathon, long gravel rides, or other endurance events, fueling should be practiced as systematically as pacing.
Example: how to build 60–90 g/h fueling
60–90 grams of carbohydrates per hour may sound like a lot, but in practice, it can be built quite simply.
For example, 60 g/h can mean:
- a sports drink with about 45 g of carbohydrates
- plus one small gel or energy chew
Or:
- two gels per hour
- water as needed
75–90 g/h can mean, for example:
- a stronger sports drink
- one gel per hour
- or several small energy portions evenly distributed
The most important thing is that fueling is not left to chance. If energy is only taken when you start feeling bad, it's often already too late.
A good rule of thumb is to start fueling early and continue consistently.
When can high carbohydrate intake be a bad idea?
More is not always better.
If the performance is extremely long, for example an ultra, a long hike, several hours of gravel riding, or a touring day, the goal of fueling is not just the highest possible carbohydrate intake per hour. In such cases, stomach comfort, consistent energy, and keeping eating enjoyable for hours are also important.
Very high carbohydrate intake can cause some people to experience:
- stomach problems
- nausea
- aversion to sweets
- problems with energy absorption
- difficulty continuing to fuel during the latter part of the performance
For long and lower-intensity performances, it may be sensible to combine sports drinks, gels, energy chews, and more solid foods.
In short:
Hard and shorter performance: higher carbohydrate intake can help.
Longer and calmer performance: consistency of energy and stomach comfort are emphasized.
Race day: only use fueling you have tested in training.
Best products for marathon and long run fueling
You can build your fueling strategy in many ways. For some, a sports drink works best, others prefer gels, and some combine several different products.
FuturePeaks' selection includes several vegan options for fueling marathons, running, cycling, and other endurance sports.
Nduranz Nrgy Drink
Nduranz Nrgy Drink is an excellent choice when you want a clear amount of carbohydrates in your drink bottle. It's a practical option for running, cycling, triathlon, and gravel rides, for example.
Nrgy Drink 45 provides 45 grams of carbohydrates per serving, and Nrgy Drink 90 contains 90 grams per serving, making it easy to build a 60–90 g/h fueling strategy around them by adding a gel or another energy source. Nrgy Drink 90 contains fewer electrolytes, making it more suitable for larger doses.
Tailwind Endurance Fuel
Tailwind Endurance Fuel is an easy option for long runs and races if you prefer to get energy in liquid form. It is especially suitable for situations where gels don't feel right or you want to keep fueling as simple as possible. It works similarly to Nduranz drinks, but all Tailwind drinks have the same amount of electrolytes, and some also contain caffeine.
Maurten Gel 100 and Gel 160
Maurten gels are popular in goal-oriented endurance sports. They are especially suitable for harder performances and situations where a precise fueling plan is desired. Maurten's hydrogel technology is stomach-friendly and optimizes absorption.
SIS Beta Fuel
SIS Beta Fuel products are especially suitable for targeting higher carbohydrate intakes. They can be a good option when you want to increase your fueling towards 80–90 grams per hour. One gel contains 40g of carbohydrates.
Näak gels and drinks
Näak offers options especially for longer performances where, in addition to energy, variety in taste and mouthfeel is desired. Näak products can be well suited for trail running, gravel cycling, and very long endurance events. Unlike many others, Näak's Ultra series drinks and gels contain BCAA branched-chain amino acids. The idea is to maintain muscle condition with a small dose of protein during long performances.
How to start developing your fueling?
If you want to improve your fueling, don't start by copying an elite marathoner's 115 g/h plan.
Start by finding out what you are doing now.
From your next long run, record:
- how long the run lasted
- what you ate and drank
- how many carbohydrates you consumed per hour
- how your stomach felt
- if your pace faded towards the end
After this, you can start to gradually increase the amount.
A good progression model could be:
| Phase | Goal |
|---|---|
| First tests | 40–50 g/h |
| Base level for long runs | 60 g/h |
| Harder long workouts | 75 g/h |
| Targeted race fueling | 90 g/h |
| Advanced, tested fueling | 90+ g/h |
This way, fueling develops in a controlled manner, and your stomach isn't surprised by too large an amount at once.
Summary: how many carbohydrates per hour should you consume?
For most marathon runners, ultra-runners, and other endurance athletes, a good target is approximately 60–90 grams of carbohydrates per hour. For a beginner or someone who has fueled little, a suitable starting level might be 30–60 g/h, while experienced athletes can, through training, reach 90 g/h or higher.
Elite marathoners fueling with over 100 g/h does not mean everyone should do the same. The most important lesson is that fueling should be planned and practiced.
In endurance sports, small differences matter. Sometimes the difference comes from training, sometimes from equipment – and sometimes from a bottle or gel.
Start moderately, test during training, and build your fueling plan so that it works specifically for you.
Products for practicing fueling
Explore FuturePeaks' endurance sports products:
