Energy Gels For Runners: How And When To Use Them

Energy gels for runners are one of the most popular ways to fuel long training runs and races. Walk into any marathon expo or running shop and you'll see shelves packed with different flavours, formulations and brands, while many major races also provide gels at selected points around the course.

For runners covering longer distances, energy gels can provide a convenient source of carbohydrate when the body's own stores are being used heavily. They can help support performance during prolonged exercise, but they aren't essential and they don't suit everyone. Some runners rely on them throughout marathon training, while others prefer sports drinks, chews, sweets or carbohydrate-rich foods.

Understanding what energy gels do, when to take them and how much carbohydrate you actually need can help you develop a fuelling strategy that works for your training and race day.

What Are Energy Gels?

Energy gels are concentrated carbohydrate products designed to provide a convenient source of fuel during exercise. They usually contain carbohydrates such as glucose, maltodextrin and fructose, often in combinations designed to deliver carbohydrate efficiently during prolonged activity.

Their biggest advantage for runners is convenience. A small packet can provide a useful amount of carbohydrate without taking up much space, making gels easy to carry in a running belt, shorts pocket or race vest.

The amount of carbohydrate varies between products, so it's important to check the label rather than simply counting the number of gels you consume. Some gels also contain electrolytes or caffeine, while isotonic or more liquid formulations contain additional water and may have different instructions about whether they need to be taken with fluid.

Why Do Runners Use Energy Gels?

Your body stores carbohydrate mainly as glycogen in your muscles and liver. During running, carbohydrate is an important source of energy, particularly as intensity increases. Those stores are limited, which is why fuelling becomes increasingly important as the duration of a run or race increases.

When carbohydrate availability becomes low during prolonged exercise, maintaining your previous running pace can become increasingly difficult. Marathon runners often describe the resulting dramatic loss of energy as "hitting the wall", although several factors can contribute to late-race fatigue.

Consuming carbohydrate during longer runs and races provides an additional source of fuel and helps maintain carbohydrate availability. Energy gels are simply one convenient way of delivering it.

When Should Runners Take Energy Gels?

Most runners don't need energy gels for an ordinary short run. If you're running for less than around an hour, your existing energy stores will usually be sufficient and taking carbohydrate during the session is generally unnecessary.

Fuelling becomes more important as exercise gets longer. For runs and races lasting beyond approximately 60 to 90 minutes, consuming carbohydrate can help support endurance performance.

Rather than waiting until you feel exhausted, start fuelling before your energy levels begin to fall significantly. Many runners take their first gel somewhere around 30 to 45 minutes into a longer run and then continue consuming carbohydrate regularly.

Exactly when you take a gel will depend on its carbohydrate content, how much carbohydrate you're aiming to consume each hour and what other fuel you're using.

How Much Carbohydrate Do Runners Need?

Thinking about grams of carbohydrate per hour is more useful than simply deciding to take a gel every 30 or 45 minutes because different energy gels contain different amounts of carbohydrate.

For prolonged endurance exercise, around 30 to 60g of carbohydrate per hour is commonly recommended. During longer endurance events lasting more than approximately two and a half hours, higher intakes of up to around 90g per hour may be beneficial for some athletes, particularly when using products containing combinations of carbohydrates such as glucose and fructose.

That doesn't mean every runner should immediately aim for 90g per hour. Higher carbohydrate intakes need to be practised during training because the digestive system may need time to adapt. Your pace, race duration, body size, previous fuelling experience and tolerance can all influence the strategy that works best for you.

How Many Energy Gels Do You Need For A Marathon?

There isn't one correct number of energy gels for every marathon runner. It depends on how long you expect to be running, how much carbohydrate each gel contains and whether you're getting carbohydrate from sports drinks, chews or other foods as well.

For example, if a gel contains around 20 to 25g of carbohydrate, taking two gels an hour would provide approximately 40 to 50g. A runner targeting a higher carbohydrate intake would need either additional gels or another source of carbohydrate.

This is why copying another runner's gel strategy isn't always sensible. Someone completing a marathon in three hours has very different fuelling requirements and opportunities from someone who will be on the course for five or six hours.

Work out your approximate carbohydrate intake per hour and practise that strategy during your longest training runs. Race day should then be a continuation of something your body already knows rather than an experiment.

How To Take Energy Gels While Running

Traditional concentrated energy gels are generally designed to be consumed with water, although instructions vary between products. Taking water alongside a concentrated gel can make it easier to consume and may reduce the likelihood of gastrointestinal discomfort.

Isotonic and more liquid gels are formulated differently and some can be consumed without immediately drinking additional water. Always check the manufacturer's instructions for the particular product you're using.

Water stations can be convenient places to take a gel during a race. They also give you somewhere to dispose of the empty packet rather than carrying it or dropping it on the course. Gel wrappers can be slippery underfoot and should always be disposed of responsibly.

Practise Using Energy Gels Before Race Day

One of the biggest mistakes runners make is trying a new energy gel for the first time during a race. What works perfectly for one runner can cause stomach discomfort for another, and brands differ considerably in texture, sweetness and carbohydrate composition.

If you're planning to use gels during a marathon or half marathon, practise with them during your longer training runs. Test not only the brand and flavour but also the quantity and timing you intend to use on race day.

It's also worth checking which nutrition products will be available at your target event. If you intend to rely on the gels supplied by the organiser, try that particular product during training first. Alternatively, carry your preferred gels so you aren't dependent on what is available on the course. Training your fuelling strategy is part of preparing for a long-distance race.

Read more about how to avoid hitting the wall here.

What About Caffeinated Energy Gels?

Some energy gels contain caffeine as well as carbohydrate. Caffeine can improve endurance performance and reduce perceived effort for some runners, which is why caffeinated gels are particularly popular during marathons and other endurance events.

However, you need to consider your total caffeine intake rather than looking at each gel in isolation. Coffee, tea, energy drinks and other sports nutrition products may also contribute caffeine during the hours before and during a race.

Some runners also find that caffeine contributes to stomach problems, nervousness or an increased urge to visit the toilet. If you're considering caffeinated gels, test them during training and keep track of approximately how much caffeine you're consuming across your entire race-day strategy.

Do You Need Energy Gels For A Half Marathon?

Whether you need energy gels during a half marathon depends partly on how long you'll be running. Faster runners may complete the distance without needing much additional carbohydrate during the race, particularly if they have eaten appropriately beforehand.

For runners who will be racing for considerably longer, taking carbohydrate during the event can become more useful. A gel during the race may help maintain carbohydrate availability, particularly towards the later miles.

As with marathon fuelling, the best approach is to test your strategy during training rather than introducing gels for the first time on race day.

What If Energy Gels Upset Your Stomach?

Stomach problems are one of the main reasons runners give up on energy gels, but the gel itself isn't always the only cause. Taking too much carbohydrate too quickly, consuming concentrated gels without appropriate fluid, dehydration, race intensity and nerves can all contribute to gastrointestinal problems.

Experiment during training with different brands, carbohydrate amounts and timings. Some runners tolerate thinner gels better than very thick products, while others prefer chews, drinks or ordinary foods.

Gradually practising carbohydrate intake during longer runs can also help your digestive system become accustomed to taking on fuel while exercising.

Dried apricots are a great alternative to gels

Are There Alternatives To Energy Gels?

Energy gels aren't the only way to fuel a long run or race. Sports drinks, energy chews, jelly sweets, bananas, dried fruit and other carbohydrate-rich foods can all contribute to your carbohydrate intake.

Some runners prefer a mixture. You might use gels because they're easy to carry during a marathon but occasionally switch to a sports drink or another food to provide a change of taste and texture.

The important factor is the amount of usable carbohydrate you're consuming and whether your chosen foods and drinks are practical and comfortable while running. If you dislike gels, there is no reason to force yourself to use them when another fuelling strategy works better.

For more ideas, read our guide to alternatives to energy gels for runners.

Read more about alternatives to running gels here.

How Much Do Energy Gels Cost?

The cost of energy gels can add up during marathon training. Using a few during a race is relatively inexpensive, but regularly using several gels on long training runs over a 12 to 16 week programme can make sports nutrition another noticeable running expense.

You don't necessarily need to use your complete race day gel allocation on every long run. However, your important marathon-specific sessions provide opportunities to practise your intended carbohydrate intake, gel timing and hydration strategy.

Buying multipacks can reduce the cost per gel, but don't buy a large quantity of an unfamiliar product until you know that you actually like the flavour and tolerate it well.

Are Energy Gels Worth It For Runners?

Energy gels can be one of the simplest ways to consume carbohydrate during long runs, half marathons, marathons and ultra-distance events. They're compact, easy to carry and allow runners to plan their carbohydrate intake relatively accurately.

They aren't essential, though. A successful endurance fuelling strategy is about consuming appropriate amounts of carbohydrate in a form that you can tolerate, not about using a particular product.

If you're new to energy gels, experiment with them during training. Pay attention to the amount of carbohydrate in each gel, how often you're taking them, how much fluid you're drinking and how your stomach responds. By race day, you should have a familiar fuelling strategy that you know works for you.

Energy gels for runners are ultimately a tool rather than a requirement. Used properly, they can make fuelling longer runs considerably easier, but the best strategy will always be the one you've practised and can comfortably maintain from the start line to the finish.

Listen to our podcast on running with gels here.