Best Energy Gels for Runners UK 2026: 7 Tested for Marathon and Long Runs

A note on advice: This is general guidance, not personalised nutrition or medical advice. Fuelling needs vary a lot between runners. For a plan tailored to you, especially if you have a medical condition or a history of gut trouble, see a registered dietitian or sports nutritionist.

Why energy gels matter on long runs

Your body stores carbohydrate as glycogen, but those stores are limited. On short easy runs you have plenty. On efforts beyond about 90 minutes you start to run low, and that is when the wall hits: legs heavy, pace dropping, brain foggy. Topping up carbohydrate as you run keeps your blood sugar stable and your muscles fuelled, so you hold pace later into a race.

Energy gels are a concentrated, portable dose of fast-acting carbohydrate, usually 20 to 30g in a small sachet. They are easy to carry, quick to take, and absorb fast. For marathons, hard half marathons, long runs, and ultras, a good gel strategy is one of the biggest performance levers you have.

How much carbohydrate do runners need per hour?

The widely accepted guidance for endurance exercise is 30 to 60g of carbohydrate per hour once you are going beyond about 90 minutes. That suits most recreational runners well. Trained athletes with practised guts can absorb more, up to around 90g per hour, but only if the carbohydrate uses a mix of glucose and fructose.

The 2:1 glucose to fructose trick

Your gut absorbs glucose and fructose through different transporters. Glucose alone tops out at roughly 60g per hour. Add fructose and you open a second pathway, letting you absorb more total carbohydrate without overwhelming your stomach. That is why high-carb gels use a 2:1 glucose to fructose ratio: it lets well-trained runners reach 80 to 90g per hour with less GI distress than glucose alone would cause.

For most runners, do not jump straight to 90g per hour. Start at 30 to 60g, see how your gut copes, and build up gradually in training if you want more. The right number is the most you can take comfortably, not the most on the label.

How to use energy gels without GI distress

GI distress, the cramping, bloating, and worse that can strike mid-run, is the number one reason runners give up on gels. Almost all of it is avoidable.

• Take most gels with water. A concentrated gel needs fluid to dilute it so your gut can absorb it. A few sips with each gel makes a huge difference. The exception is isotonic gels, pre-diluted to go down without water.
• Practise in training. Your gut is trainable. Use your gels on long runs so race day is a known quantity, never an experiment.
• Space them out. Take a gel every 30 to 45 minutes rather than several at once, for a steady supply without flooding your stomach.
• Avoid caffeine early. Save caffeine gels for the back half of a race when you need the lift.
• Mind fibre and fat before a race. What you eat beforehand also affects your gut. Keep pre-race food simple and low in fibre.

If gels never sit well for you despite practice, chews, drink mixes, and real food like bananas are valid alternatives carrying the same carbohydrate.

The 7 best energy gels for runners UK 2026

Here are seven gels widely available in the UK, with what each is best for, what it does well, where it falls short, and the typical UK price. Carb figures are per gel and approximate.

1. Maurten Gel 100 (around 3.50 pounds) - Best for sensitive stomachs

Best for: Runners who suffer GI distress with normal gels.

Does well: A hydrogel technology encapsulates the carbohydrate, so it sits lightly in the stomach and many runners tolerate it when nothing else works. Around 25g of carbohydrate, clean taste, no strong flavours. A favourite of elite marathoners.

Does not: Easily the priciest gel here, and the texture is unusual, a slightly jelly-like blob that divides opinion.

2. SiS Go Isotonic (around 1.50 pounds) - Best no-water gel

Best for: Runners who hate carrying water or forget to drink with gels.

Does well: SiS Go Isotonic is the classic isotonic gel: pre-diluted so you can take it without water and it still goes down easily. Around 22g of carbohydrate, light texture, widely stocked in UK shops, and good value. A sensible default for first-time gel users.

Does not: The isotonic format means a larger, slightly heavier sachet, and the carbohydrate per gel is a touch lower than concentrated rivals.

3. Precision Fuel 30 (around 2.50 pounds) - Best for high-carb fuelling

Best for: Runners pushing toward higher carb intakes per hour.

Does well: The PF 30 delivers a clean 30g of carbohydrate in a 2:1 glucose to fructose ratio, making it easy to hit precise fuelling targets. Neutral, not too sweet, and easy on the gut for many. Precision also publish clear fuelling guidance, which helps you plan.

Does not: Best taken with water, and at this carb load you do need to practise to tolerate several per hour.

4. GU Energy Original (around 2 pounds) - Best for flavour variety

Best for: Runners who want lots of flavour choice and a proven gel.

Does well: A long-standing favourite with around 22g of carbohydrate, a huge range of flavours, and added sodium plus small amounts of amino acids. Caffeinated options are available for later in a race. Thicker texture that some runners love.

Does not: The thicker consistency needs water, and the sweetness of some flavours can be much over a long race.

5. Torq Gel (around 1.80 pounds) - Best natural-leaning option

Best for: Runners who want a 2:1 ratio gel with natural flavours.

Does well: Torq uses a 2:1 glucose to fructose blend for efficient absorption, around 28g of carbohydrate, and leans on natural flavours and colours. A smooth, pleasant texture and a strong UK following, especially among trail and ultra runners.

Does not: Take with water, and the natural flavours, while pleasant, are a touch milder than the sweeter mainstream gels.

6. High5 Aqua Gel (around 1.60 pounds) - Best lightest texture

Best for: Runners who find normal gels too thick and sticky.

Does well: The Aqua format is a thinner, more drinkable gel, around 23g of carbohydrate, that goes down easily even without much water. Good value, widely available, and gentle on the stomach for many. A nice bridge between a gel and a drink.

Does not: The watery format means a larger sachet, and the carbohydrate per gel is moderate rather than high.

7. Veloforte (around 3 pounds) - Best all-natural gel

Best for: Runners who want real-food ingredients and no artificial additives.

Does well: Veloforte uses natural carbohydrate sources, fruit, and botanicals, with around 24g of carbohydrate and genuinely pleasant flavours. Great for runners with a sensitive palate who dislike the synthetic taste of mainstream gels, and a 2:1 ratio in many products.

Does not: Premium price, and the real-food base gives a slightly thicker, more textured gel that suits some runners more than others.

Comparison table: all 7 at a glance

When should you take caffeine gels?

Many gels come in caffeinated versions, usually 25 to 100mg per gel. Caffeine can genuinely help endurance performance and reduce how hard the effort feels, but timing matters. Save caffeine for the back half of a race, when fatigue is biting, rather than burning it early. Stacking too many caffeine gels can cause jitters, a racing heart, and gut upset, so know your tolerance and, as ever, practise in training. If caffeine late in the day disrupts your sleep, factor that into evening races.

Common gel mistakes runners make

• Trying a new gel on race day. The classic error. Always rehearse your exact fuelling in training first.
• Taking gels without water. Concentrated gels need fluid to absorb. No water often means a gut ache, unless the gel is isotonic.
• Leaving it too late. Start fuelling before you feel empty. Once you have hit the wall, gels are slow to rescue you.
• Too much caffeine. Stacking caffeine gels can backfire with jitters and gut trouble. Use them sparingly and later.
• Ignoring your own gut. Some runners simply tolerate certain brands better. If one does not agree with you, try another rather than forcing it.

How Edge fits in

Gels fuel the run. They do not tell you what to run, or when, or how to build toward a goal race. That is the job of a structured plan, and it is what Edge does.

With Edge, a real coach builds your starting plan within 24 hours of signing up, then it is enhanced with AI. Your plan blends running with general strength and mobility, pushes structured workouts to your Garmin and Coros watch and imports completed sessions back, and works on a native Apple Watch training app. Flexi Swap moves sessions around your week, and Edge AI answers in about 30 seconds, with the option to speak to coaches too.

To be straight with you: Edge does not have nutrition or fuelling guidance built into the plans. We focus on the training. For your gel strategy, use the general guidance here, practise it on your Edge long runs, and for a tailored plan see a registered dietitian. Edge has 17,000+ UK members, a free 7-day trial, and costs 19.99 pounds a month or 119.99 pounds a year. Our aim is making fitness feel good for everyone.

Frequently asked questions

How many energy gels should I take in a marathon?

For most runners, aim for 30 to 60g of carbohydrate per hour, which usually works out at one to two gels per hour. Over a four to five hour marathon that is often around five to eight gels. Practise your exact number and timing on long training runs first, and take each gel with a few sips of water unless it is isotonic.

Do I need to take gels with water?

Yes, for most gels. Concentrated gels need fluid to dilute them so your gut can absorb the carbohydrate comfortably, so take a few sips of water with each one. The exception is isotonic gels, like SiS Go Isotonic, which are pre-diluted and designed to be taken without extra water.

What is the 2:1 glucose to fructose ratio?

Glucose and fructose are absorbed by different transporters in your gut. Glucose alone tops out around 60g per hour, but adding fructose opens a second pathway, so a 2:1 glucose to fructose blend lets trained runners absorb up to about 90g of carbohydrate per hour with less GI distress. Most runners should still start at 30 to 60g per hour.

When should I take a caffeine gel?

Save caffeine gels for the back half of a race, when fatigue sets in and the lift is most useful, rather than taking them early. Caffeinated gels usually contain 25 to 100mg of caffeine. Avoid stacking too many, which can cause jitters and gut upset, and practise with them in training so you know your tolerance.

Can energy gels cause stomach problems?

They can, and GI distress is the main reason runners abandon gels. Most of it is avoidable: take gels with water, practise them in training so your gut adapts, space them out, go easy on caffeine, and keep pre-race food low in fibre and fat. If one brand never agrees with you, try another, as tolerance is very individual.

How long before I run should I take a gel?

On runs over about 90 minutes, take your first gel around 30 to 45 minutes in, before you feel empty, then one every 30 to 45 minutes after that. Starting early keeps your blood sugar steady. For shorter runs under 90 minutes, most runners do not need gels at all, and water is usually enough.