Energy Gels Explained: How Much and When Should You Take Them?
Energy gels are everywhere at running events.
You'll see runners carrying them in belts, stuffing them into shorts and taking them at aid stations throughout half marathons and marathons.
But if you're new to sports nutrition, they can also be confusing.
When should you take your first gel? How many do you need? Do you need water with them? And what's the difference between a normal gel and a caffeinated one?
Here's what runners need to know.
What Is an Energy Gel?
An energy gel is essentially a concentrated and portable source of carbohydrate designed to be consumed during exercise.
Carbohydrate is an important fuel source during running, particularly at higher intensities.
Your body stores carbohydrate as glycogen in your muscles and liver, but those stores are limited.
As exercise becomes longer, consuming additional carbohydrate can help provide fuel while you're running.
Energy gels are simply one convenient way of doing that.
They're popular because they're:
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Small
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Lightweight
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Easy to carry
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Quick to consume
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Easy to measure as part of a fuelling plan
But gels aren't magic.
Ultimately, the important thing is the carbohydrate they provide.
How Much Carbohydrate Is in an Energy Gel?
This varies considerably between products.
One gel might provide approximately 20–25g of carbohydrate, while another larger product may provide substantially more.
That's why simply saying:
“Take one gel every 30 minutes.”
isn't particularly useful without knowing which gel you're taking.
Instead, look at the nutritional information on your chosen product and determine how much carbohydrate it provides.
Then build your strategy around your approximate carbohydrate requirement per hour.
We've covered this in detail in our guide to how to fuel your runs for a 10K, half marathon and marathon.
How Much Carbohydrate Do Runners Need?
Your requirements depend primarily on how long you're exercising.
As a broad guide:
| Exercise Duration | Carbohydrate During Exercise |
|---|---|
| Under approximately 60 minutes | Usually little or none required |
| Around 1–2.5 hours | Approximately 30–60g per hour |
| Longer than approximately 2.5 hours | Around 60–90g per hour may be appropriate if practised and tolerated |
These are guidelines rather than compulsory targets.
Your individual requirements and tolerance matter.
A runner completing a half marathon in 90 minutes has different requirements from someone completing a marathon in five hours.
How Many Gels Is 60g of Carbohydrate?
Let's use a simple example.
If your chosen gel contains 25g of carbohydrate:
1 gel = 25g
2 gels = 50g
3 gels = 75g
So if you were aiming for approximately 50g of carbohydrate per hour, two of those gels would provide roughly that amount.
But if your chosen gel contains 40g of carbohydrate, the calculation changes.
This is why runners should get into the habit of checking the grams of carbohydrate per serving, rather than assuming every gel is nutritionally identical.
When Should You Take Your First Energy Gel?
Don't wait until you're exhausted.
One of the most common mistakes runners make is treating a gel like an emergency energy boost.
They wait until they suddenly feel depleted and then take one.
For longer events, it's generally better to begin fuelling according to a planned schedule before significant fatigue develops.
For example, a runner might begin consuming carbohydrate around 20–30 minutes into a prolonged race and continue at regular intervals according to their planned hourly intake.
The exact timing depends on:
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Your race duration
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Your target carbohydrate intake
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The carbohydrate content of your products
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What you've successfully practised in training
Think of gels as a way of maintaining your fuelling strategy, not rescuing it once things have already gone wrong.
Do You Need a Gel for a 5K or 10K?
Usually not during the race itself.
For many runners completing a 5K or 10K in under approximately one hour, existing carbohydrate stores combined with appropriate pre-race nutrition should generally be sufficient.
That doesn't mean runners never use carbohydrate around shorter races.
Some may consume carbohydrate shortly before the start, particularly for harder race efforts.
But carrying several gels for a 45-minute 10K is generally unnecessary.
As race duration increases, during-run carbohydrate becomes much more relevant.
How Many Gels for a Half Marathon?
It depends on your finishing time and the gel you're using.
Suppose you're aiming for a two-hour half marathon and your chosen gel contains 25g of carbohydrate.
If your target is approximately 40–50g of carbohydrate per hour, you might build a strategy involving several gels throughout the race, potentially alongside carbohydrate consumed immediately before the start.
For example:
Before the start: Optional gel depending on your strategy
30 minutes: Gel
60 minutes: Gel
90 minutes: Gel
Whether you need more or less depends on your total carbohydrate target, finishing time and whether you're also getting carbohydrate from sports drinks or other products.
Don't simply copy this schedule.
Practise it first.
How Many Gels for a Marathon?
This is where planning becomes much more important.
If you're running for four hours and targeting around 60g of carbohydrate per hour, you're potentially looking at approximately:
240g of carbohydrate across the race.
If each gel contains 25g, obtaining all of that carbohydrate exclusively from gels would require a substantial number of gels.
That's one reason many marathon runners combine different carbohydrate sources.
For example:
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Energy gels
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Chews
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Carbohydrate drinks
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Sports drinks
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Other familiar carbohydrate foods
You don't need to obtain every gram of carbohydrate from a gel.
Your stomach — and your taste buds — may appreciate some variety after several hours.
Do You Need to Drink Water With Energy Gels?
This depends on the product.
Many traditional concentrated gels are designed to be consumed alongside water.
Water can make them easier to swallow and helps dilute the carbohydrate entering your digestive system.
Other products have a thinner or more liquid consistency and may be designed to be easier to consume without immediately drinking water.
The safest approach is simple:
Follow the instructions for the specific product you're using.
Don't assume every gel should be consumed in exactly the same way.
This is another reason to test your chosen product during training.
What's the Difference Between Regular and Hydro Gels?
You'll sometimes see products described as hydro gels, aqua gels or similar.
These typically contain more water and have a thinner consistency than traditional concentrated gels.
Some runners find this texture easier to consume while running.
Others prefer the smaller size and thicker consistency of a traditional gel.
Neither format is automatically better.
It's largely about finding the combination of carbohydrate content, consistency and flavour that works for you.
Our energy gels and running nutrition collection contains several different gel formats if you want to experiment during training.
What About Maurten Gels?
Maurten takes a slightly different approach.
Its Gel 100 range uses the company's Hydrogel Technology with a mixture of glucose and fructose.
A standard Maurten Gel 100 provides 25g of carbohydrate, while larger options such as Gel 160 provide more carbohydrate per serving.
This can make the maths relatively straightforward when building a race plan.
For example:
2 × 25g gels = 50g carbohydrate
3 × 25g gels = 75g carbohydrate
That doesn't mean Maurten is automatically the right choice for every runner.
Taste, texture, cost and gastrointestinal tolerance all matter.
You can explore the full Maurten range and test different options during training.
What About Caffeinated Gels?
Some energy gels also contain caffeine.
Caffeine can support endurance performance, which is why caffeinated products are popular during longer races.
But you need to think about your total caffeine intake, not simply how many caffeinated gels you can take.
Your total might include:
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Coffee before the race
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Pre-workout products
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Caffeinated gels
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Caffeinated chews
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Caffeinated drinks
That can add up quickly.
You also don't necessarily need every gel in your race plan to contain caffeine.
Some runners use non-caffeinated carbohydrate products for much of the race and strategically introduce caffeine later.
Whatever approach you choose, test it in training first.
Why Do Energy Gels Upset Some Runners' Stomachs?
Gastrointestinal discomfort during running can have several contributing factors.
The gel itself isn't necessarily the sole cause.
Problems may occur when runners:
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Consume too much carbohydrate too quickly
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Use products they haven't practised with
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Take concentrated products differently from the manufacturer's instructions
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Consume large amounts of carbohydrate while also drinking highly concentrated sports drinks
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Eat too close to running
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Attempt a much higher carbohydrate intake than they're accustomed to
Individual tolerance also varies.
One runner might love a particular gel while another can't tolerate its texture or formulation.
We've covered this in more detail in our guide to cramping, heavy sweating and stomach issues.
Can You Train Your Stomach to Handle More Gels?
To an extent, you can become more accustomed to consuming carbohydrate while exercising.
That's why long runs are so useful.
If your marathon strategy involves consuming carbohydrate regularly for four hours, your first attempt shouldn't be on marathon morning.
Instead, gradually practise your intended intake during appropriate long training sessions.
Use those sessions to determine:
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How much carbohydrate you tolerate
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Which products work best
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Which flavours you prefer
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Whether you prefer gels, chews or drinks
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How frequently you want to fuel
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How much fluid works alongside your nutrition
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Whether caffeine agrees with you
Your race-day nutrition should be something you've rehearsed.
Do All Your Gels Need to Be the Same?
Absolutely not.
In fact, variety can make a long race more manageable.
After several hours, repeatedly consuming the same flavour and texture can become unpleasant.
You might prefer a combination such as:
Standard gels + chews + carbohydrate drink
or:
Thicker gels + hydro gels + a caffeinated option later in the race
There isn't one correct combination.
The goal is to achieve your intended carbohydrate intake using products that you can comfortably consume for the duration of your event.
Gels Aren't Your Only Option
If you don't enjoy energy gels, don't force yourself to use them simply because other runners do.
Alternative carbohydrate sources include:
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Energy chews
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Gummies
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Sports beans
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Carbohydrate drinks
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Energy bars
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Waffles
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Other familiar carbohydrate foods
The Run Hub's energy gels and running nutrition range includes several of these formats alongside traditional gels.
The important question isn't:
“Which gel should every runner use?”
It's:
“Which fuelling strategy allows me to consistently consume the carbohydrate I need without upsetting my stomach?”
Practise Before Race Day
If there's one rule worth remembering, it's this:
Nothing new on race day.
Don't switch gel brands the night before your marathon because someone at the expo told you they're better.
Don't suddenly double your carbohydrate intake.
Don't introduce caffeine if you've never used it during training.
And don't rely on whatever happens to be available at an aid station unless you've already tested it.
Use your long runs to build and refine your strategy.
By race morning, you should know:
What you're taking.
How much carbohydrate it provides.
When you're taking it.
How you're carrying it.
Whether you need water with it.
And most importantly:
Whether your stomach tolerates it.
The Takeaway
Energy gels are simply a convenient way to consume carbohydrate during prolonged exercise.
Instead of blindly following a rule such as “one gel every 30 minutes,” understand how much carbohydrate your chosen product actually contains and build your strategy around your approximate hourly requirements.
For shorter runs, you may not need a gel at all.
For half marathons and particularly marathons, gels can become a very convenient way of consistently consuming carbohydrate throughout the race.
But there isn't one perfect gel or schedule for everyone.
Choose your products, calculate your carbohydrate intake, practise your strategy and find what works for you.
