TL;DR: Caffeine and carbohydrate can be combined as part of an energy plan for longer training sessions and competition.
- Many aim for about 30–60 g of carbohydrate per hour for sessions over 60–90 minutes.
- For healthy adults, up to about 200 mg of caffeine per dose and up to about 400 mg per day are often mentioned.
- Timing can be planned before the start, right before the start, and during the session, depending on tolerance and stomach comfort.
- Always test gels, drinks, and chews in training before using the strategy in competition.
- People with sensitivity, sleep issues, pregnancy/breastfeeding, or relevant diagnoses should be extra cautious with caffeine.
The coffee cup on the table, carbohydrates in the bottle, and a gel in the pocket are everyday life for many endurance athletes. The question is whether it makes sense to combine caffeine and carbohydrates when you train or compete—and how you can do it in a way that feels manageable and fits your body.
In this guide, you’ll get practical advice on how to use the combination as part of your energy plan, which amounts are typically used, and when it may be relevant to dial it back or choose caffeine-free alternatives.
Why it can be beneficial to combine caffeine and carbohydrates
During prolonged exercise, carbohydrates are an important energy source. Carbohydrates contribute to replenishing glycogen stores after physical activity, and during activity many use a strategy of ongoing intake to support energy availability. That’s why many choose to aim for around 30–60 g of carbohydrates per hour during longer sessions, often via sports nutrition designed to be practical to consume during activity.
Caffeine is a stimulant that affects the central nervous system. Studies suggest that for many, caffeine can:
- Contribute to a feeling of increased alertness
- Contribute to increased attention
- Is typically used in connection with endurance training, where some experience performance support at appropriate doses
If you combine the two, you can get:
- Carbohydrates as part of a plan for energy supply during longer sessions
- Caffeine as a possible supplement that some use to support focus during periods of high strain
That’s why it’s common for sports nutrition to combine both in the same product—for example a caffeine gel, where you get carbohydrates and caffeine in one solution. If you want an easy way to test this in training, consider starting with a single caffeine gel on a long session day.
How much caffeine and carbohydrate is typically relevant
For healthy adults, European authorities typically cite the following levels as a starting point:
- Up to about 200 mg of caffeine per single dose
- Up to about 400 mg of caffeine over the course of a day
These levels are often described as ranges where many may have a lower likelihood of unwanted effects such as restlessness, sleep problems, and palpitations, but tolerance varies from person to person.
In practice, this means that some endurance athletes typically aim for:
- Around 3 mg of caffeine per kg of body weight before competition, which is about 200 mg for a 70 kg person
- Possibly a smaller intake during the session, still with a focus on staying below about 400 mg on the day
When it comes to carbohydrates during training and competition, typical recommendations are:
- For durations over 60–90 minutes, about 30–60 g of carbohydrates per hour, for example via gels, chews, or a carbohydrate drink
Here it can be relevant to have a fixed carbohydrate base in your bottle, so it’s easier to maintain a steady intake. A simple option is using a carbohydrate-electrolyte drink mix like Carbo Race Electrolyte. Also remember to account for fluids and electrolytes based on sweat loss, temperature, and intensity.
Timing caffeine and carbohydrates in your energy plan
Timing is about both when you experience the greatest benefit and how your stomach responds. Thinking in phases can help when planning your intake.
A simple way to structure it is:
- Before the start, about 30–60 minutes: A light, carbohydrate-rich meal or snack that doesn’t sit heavy. Some also choose a moderate caffeine dose of about 150–200 mg, depending on body weight, habit, and tolerance.
- Right before the start: A smaller amount of carbohydrates, for example a gel, can be a practical part of the plan. Here you can choose with or without caffeine, depending on how much you’ve already had.
- During longer sessions from about 90 minutes: Steady carbohydrate intake via drink, gels, or chews. Many choose a caffeine gel in the final part if they want caffeine later in the session.
A simple example for a two- to three-hour event could look like this:
- Before the start: Carbohydrate-rich meal and possibly 150–200 mg caffeine, for example via coffee or a pre-workout shot
- During: 30–60 g of carbohydrates per hour from sports drink and gels
- Final part: One caffeine gel as a possible supplement, followed by water
If you want to find the solution that suits you best, it’s a good idea to test different combinations of gels and chews with and without caffeine in training sessions where you can evaluate how your stomach and energy feel. A practical approach is to compare a regular gel like Energy Gel versus a caffeine option on similar sessions.
How to reduce the risk of stomach issues
When both intensity and duration increase, the stomach can become more vulnerable. Both carbohydrates and caffeine can cause challenges if you take too large amounts at once or choose a form that’s hard to handle at a high heart rate.
Typical causes of stomach issues are:
- Doses that are too large in a short period of time
- Highly concentrated products without sufficient water
- Completely new products or doses first tried on race day
You can increase the chances of a stomach that works better by:
- Splitting intake into smaller portions, for example one gel every 30 minutes instead of two at once
- Washing gels down with water so the concentration in the stomach doesn’t get too high
- Testing your strategy in training several times before using it in competition
- Matching product form to intensity, where gels and drinks are often easiest at high heart rate, while chews and bars typically work better at a slightly lower pace
If you have a sensitive stomach, you might consider limiting caffeine to one well-chosen source—for example a single caffeine gel late in the session—and letting the rest of your energy come from caffeine-free products.
Choosing gel, drink, or chews
The most important thing is to choose a solution that fits you and your plan. The format should match your sport, your pace, and your personal preference, and it’s completely normal to have to test and adjust before it really clicks.
- Carbohydrate drink as a base: A sports drink can be a practical cornerstone because you can get fluids, carbohydrates, and electrolytes in the same solution. Small sips regularly can make it easier to maintain a stable intake, especially on the bike or during longer running sessions.
- Gels with and without caffeine: Gels provide a concentrated carbohydrate source that’s easy to consume during activity. A common strategy is to use caffeine-free gels early and save one to two caffeine gels for the final part, depending on race length and your tolerance.
- Chews for variation: Chews can be a good supplement when you have the capacity to chew, for example on moderately hard sessions or in the calmer part of a long race. They can add variety if you get tired of exclusively liquid energy. For quick, easy-to-dose carbs in a chewable format, some athletes also use products like Dextrose Bites.
If you want to understand caffeine even better, it can be helpful to read more about how it affects the body and how it typically fits into sports nutrition. That can make it easier to adjust both doses and timing so it fits your training and your races.
Who should be extra cautious with caffeine
Caffeine is widespread, but it isn’t necessarily the right choice for everyone, and higher doses aren’t automatically better. Too much can increase the risk of discomfort and can affect both your stomach and sleep.
You should be especially cautious if you:
- Often experience restlessness, palpitations, or sleep problems after coffee or energy drinks
- Already drink a lot of coffee, tea, cola, or energy drinks in everyday life
- Train late in the day, because caffeine can affect your sleep several hours later
- Are pregnant or breastfeeding, where a lower maximum for caffeine intake is usually recommended
- Have cardiovascular issues or another relevant diagnosis and therefore should talk to a healthcare professional before using high caffeine doses
For children and adolescents, authorities generally recommend keeping caffeine intake very low. Caffeinated sports nutrition is typically aimed at adults who can take responsibility for dose, timing, and possible side effects.
How to get started step by step
If you want to use caffeine and carbohydrates more intentionally in your training, it can be relevant to view it as part of your overall energy planning—on par with your training program, recovery, and goal setting.
- Get an overview of your caffeine tally by counting everything, including coffee, tea, cola, energy drinks, gels, and pre-workout products. The goal is to know your total intake and, for many, to stay under about 400 mg per day.
- Build a carbohydrate base by using a sports drink or other carbohydrate sources so you typically hit 30–60 g of carbohydrates per hour for sessions over 60–90 minutes.
- Add one caffeine source at a time and start, for example, with one caffeine gel in the final part of a long training session. Then assess both how you experience focus/energy and how your stomach responds.
- Adjust based on your experience by increasing or decreasing the dose, shifting the timing, or switching between gel, drink, and chews until you have a strategy that works for you—even at high intensity.
The combination of caffeine and carbohydrates can be used as a tool in an overall strategy for energy and focus during endurance training. The effect and tolerance depend on dose, timing, and individual factors. Use training days to test your plan so you know what works for you when it matters.