Long runs aren’t only about kilometers and pace. They’re also about how you plan your energy intake along the way, so you can better support performance all the way to the last meter. When you’re out for more than two hours, a well-thought-out carbohydrate strategy can help you maintain a more stable pace and avoid a significant energy dip.
In this overview, you’ll get a concrete, practical guide to carbohydrate intake for runs over two hours. The focus is on how you can plan your intake on long training runs, half marathons, marathons, and ultraruns, so your fueling plan matches your goals and experience.
Why carbohydrates become more important after around two hours
The body’s glycogen stores—carbohydrate reserves in muscles and liver—typically last for about one to two hours of running at moderate to high intensity. After that, stores can gradually be depleted if you don’t top up continuously.
If you don’t take in carbohydrates along the way, many runners experience, among other things:
- A drop in pace, even though heart rate is high
- Heavy legs that may feel less responsive
- Harder to maintain focus and motivation
- Increased risk of a pronounced energy crash after 2.5–3 hours, often referred to as “the wall” in the marathon
It can be difficult to compensate for a large energy deficit late in the run. That’s why many choose to start early and refuel steadily, so they continuously support the work the body needs to deliver.
How many grams of carbohydrates per hour for running over two hours
Guidelines for endurance training often indicate ranges for carbohydrate intake per hour that can be used as a starting point:
- Runs of one to two hours, typically around 30–60 g of carbohydrates per hour
- Runs over two hours, for example half marathons, marathons, or ultras, often 60–90 g of carbohydrates per hour as a starting point
Where you should fall within the range depends, among other things, on intensity, training level, and what your stomach is used to. For many recreational runners, 40–60 g per hour can be a realistic place to start and adjust from.
The higher level around 75–90 g per hour can typically be most relevant for runners who:
- Train purposefully and run at a high average speed
- Are accustomed to long training sessions with energy intake
- Have deliberately worked on training their stomach to handle a higher carbohydrate intake
A good first step is to ask yourself: How many grams of carbohydrates per hour will I aim for in this specific run? Once you have a number, it becomes easier to make a simple plan you can remember, even when your heart rate is high.
Timing and rhythm of intake during running
Many wait to take carbohydrates until they can clearly feel their energy dropping. For runs over two hours, that can be a challenge for some if the goal is to support a stable pace all the way.
A more planned approach to timing could be:
- For runs over 60–75 minutes, start carbohydrate intake after about 20–30 minutes
- For runs over two hours, take the first gel about 40–60 minutes in
- Continue thereafter with carbohydrates about every 30–45 minutes
The most important thing is to find a rhythm that is easy to execute in practice. For example, you can aim for a smaller intake every half hour—either as a gel, chews, or carbohydrate drink—and use your watch with alarms or fixed kilometer markers.
A steady rhythm often provides a more stable carbohydrate intake, can feel gentler on the stomach, and may help reduce large swings in energy along the way.
Gels, chews, and a bottle as tools in your plan
Once you’ve set a target in grams of carbohydrates per hour, it’s about translating it into specific products. During running, the most commonly used sources are typically gels, chews, and carbohydrate drink in your bottle.
Energy gels often provide around 20–30 g of carbohydrates per gel and are developed to be easy to consume during activity. That’s why many runners use gels as a practical part of the plan on longer outings. You can see the selection of energy gels for running here: energy gels for running.
Energy chews work in practice the same way as a gel, but in small, chewable pieces. A pouch is roughly equivalent to a gel, but can be spread out over 20–30 minutes. For some, that can make it easier to keep an even rhythm and avoid large portions at once. See the selection here: energy chews as an alternative to gel.
Carbohydrate drink such as Carbo Race combines fluid, carbohydrates, and typically electrolytes, so you get both energy and salts in the same solution. That can be practical on hot days and for long sessions where you need to carry fluids anyway. You can see an example of Carbo Race Electrolyte here: Carbo Race Electrolyte for your bottle.
Examples of simple carbohydrate plans per hour
The exact numbers depend on which products you use, but here are three simple ways to hit about 60 g of carbohydrates per hour.
- Strategy 1, Gel as the base with two gels per hour and water according to thirst
- Strategy 2, Carbohydrate drink as the base with one gel on top per hour
- Strategy 3, Chews spread out over an hour combined with carbohydrate drink
A gel-based strategy could, for example, be two gels per hour at about 25–30 g of carbohydrates each, supplemented with water at aid stations or in a handheld bottle.
A combination of drink and gel could be 500 ml of Carbo Race per hour, which typically provides around 30–35 g of carbohydrates, plus one gel with about 25 g. That totals around 55–60 g of carbohydrates per hour split between both drink and gel.
A strategy with chews and drink could be one pouch of chews spread over an hour, equivalent to about one gel, along with 300–500 ml of carbohydrate drink per hour. Here you distribute both fluid and energy in small bites and sips, which many prefer for stomach comfort.
Choose the combination that is easy to remember, suits your preferences for taste and texture, and works practically in terms of what you can carry or access on the route.
Electrolytes and fluids on long and hot runs
Carbohydrates are only one part of your fueling plan. When you run long—especially in hot or humid weather—you also lose fluid and electrolytes such as sodium, potassium, magnesium, and calcium through sweat.
Electrolytes, including magnesium, contribute to electrolyte balance. Potassium contributes to normal muscle function. Magnesium contributes to normal muscle function and to reducing tiredness and fatigue. Therefore, many runners choose to combine carbohydrates with electrolytes on long and hot runs.
For example, you can use a carbohydrate drink such as Carbo Race Electrolyte as the base in your bottle, or supplement with electrolyte tablets in water if you want to keep carbohydrate intake lower but still support fluid balance. You can see the full selection of electrolytes for long and hot runs here: electrolytes for long and hot runs.
For runs over two hours, you can drink according to thirst and be extra attentive in hot weather. Spread fluid intake out in small sips and avoid making the drink too concentrated. A high carbohydrate concentration without a corresponding amount of water can, for some, increase the risk of stomach issues.
How to train your stomach for higher intake
Some runners can, over time, tolerate up to 90 g of carbohydrates per hour with an appropriate mix of sources. However, that isn’t the starting point for everyone, and it can require that you gradually get your stomach used to it—not just your fitness.
A practical way to work on it could be:
- Start around 25–40 g per hour on your long runs
- Increase gradually by about 5–10 g per week on selected key sessions
- Test new products and higher doses in training—never for the first time in a race
- Distribute intake so you get a little every 15–20 minutes rather than large doses once per hour
- Adjust the mixing ratio in your bottle if your stomach reacts, and if necessary move some of the carbohydrates from the drink to gels or chews
If you have specific health conditions—for example diabetes—are pregnant, or take medication, it’s a good idea to talk to a professional before making major changes to your carbohydrate intake.
Concrete examples of carbohydrate plans for long runs
Below you’ll find three examples of what a carbohydrate plan can look like in practice. The numbers are indicative and can be adjusted based on intensity, experience, and stomach comfort.
For a half marathon training run of about 2:15–2:30 hours with a goal of around 40–50 g of carbohydrates per hour, you could, for example, eat a carbohydrate-rich meal two to three hours beforehand and during the run take a gel after about 40–45 minutes, another gel around 1:30, and supplement with water according to thirst. That can provide a simple plan for you if you’re getting started with your first longer runs.
For a marathon around 3:30 hours with a goal of about 60 g per hour, you can arrive with topped-up stores from an appropriate pre-race meal and during the run take about one gel every 30–35 minutes combined with 300–500 ml of Carbo Race Electrolyte per hour, depending on temperature and thirst. The total amount can be adjusted as you get to know your stomach and your needs.
For marathons and ultraruns over 4:30 hours with a goal of 50–75 g per hour and extra focus on stomach comfort, it often comes down to variety and steady intake over many hours. A typical approach can be Carbo Race as the base in your bottle, alternating between gels and chews to vary taste and texture, and possibly small bites of a bar or banana on the calmer sections of the route. Here, many choose to start eating early and continue in small, regular amounts.
After the run and focus on recovery
When you stop the watch, recovery begins. After a long run, the body typically needs carbohydrates to rebuild glycogen stores and protein to support maintenance and building of muscle mass.
It can be relevant to get both carbohydrates and protein after the run as part of an overall meal or snack. Here, a recovery product can be a practical solution because you get a combination in one drink. You can see PurePower’s selection of recovery after long runs here: recovery after long runs.
With a clear carbohydrate strategy in grams per hour, a conscious choice of gels, chews, and drink, and a gradual adaptation to the intake, you can increase the likelihood of maintaining a more stable energy level on runs over two hours. It doesn’t change the demands of the distance, but it can make energy planning more predictable in practice.