Best energy gels for a marathon and half marathon: how to choose by use

There is no single best energy gel for a marathon. The best gel is the one that gives you your hourly carbohydrate target, in a texture your stomach accepts at race pace, with caffeine you have practised. For most runners that is a 22 to 30 g gel every 20 to 30 minutes. If you want 75 to 90 g per hour, pick a gel that mixes glucose and fructose. If your stomach is the problem, pick a thin gel that needs no extra water. Then test it on long runs before you trust it.

This guide groups gels by what you need them for, not by brand. Every number comes from the brand’s own product page. Where the page did not show a number, the table says “not listed”. Recipes and prices change, so check the label of the exact flavour you buy. For a wider table of 25 gels and the basics of when to take them, see our energy gel comparison guide.

The short answer: best gels by use

• High-carb racing (75 to 90 g per hour): Precision Fuel PF 30 or Neversecond C30 (30 g, three an hour gives 90 g), Maurten Gel 100 (25 g, three an hour gives 75 g), or SiS Beta Fuel (40 g, two an hour gives 80 g). All mix glucose and fructose.
• Sensitive stomach or no water handy: SiS GO Isotonic (22 g) or HIGH5 Energy Gel Aqua (23 g). Both are thin and the brands say you need no extra water.
• Caffeine you can dose: GU (20 or 40 mg), HIGH5 Energy Gel Caffeine (30 mg), SiS GO Energy + Caffeine (75 mg), Neversecond C30+ (75 mg), Maurten Gel 100 CAF 100 and PF 30 Caffeine (100 mg each).
• Budget: compare price per 10 g of carbohydrate. Among the brand stores checked, HIGH5 Energy Gel and GU Energy Gel cost the least per gram.
• Real food: Spring Energy, with fruit, rice, and maple syrup. Fewer carbs per packet, so you need more of them.
• Half marathon: any 22 to 30 g gel you have tested. Most runners need one to four.

The numbers: 10 gels from the brand’s own pages

Values are per gel. “Not listed” means the number was not on the brand’s product page when we checked; it may be on the pack. Ratios are written the way each brand writes them.

Two things stand out. First, the carbohydrate column runs from 21 g to 40 g, so “one gel” can mean almost twice the dose of another. Count grams, never packets. Second, most brands do not show sodium on the product page, and the ones that do range from 45 mg to 200 mg. Gels are rarely a full sodium plan on their own.

For high-carb racing: 75 to 90 g per hour

World Athletics’ consensus statement suggests trained runners can try up to 90 g of carbohydrate per hour in races over two and a half hours. Research on multiple transportable carbohydrates explains why the gel matters here: glucose and fructose use different routes into the body, so a blend lets you absorb more per hour than glucose or maltodextrin alone. Above about 60 g per hour, pick a gel that lists both.

• Bigger gels mean fewer packets but a bigger dose each time. If a 40 g gel sits heavy at race pace, take half, then the other half 10 to 15 minutes later.
• Neversecond C30 is the only gel in this group that shows sodium on its page, at 200 mg. That helps salty sweaters but counts toward your sodium total.
• High intakes are a trained skill. If you have never gone above 60 g per hour in a long run, race day is not the place to start.

For a sensitive stomach

Most gel trouble comes from three things: too much carbohydrate at once, too little water with a thick gel, and no practice. Thin gels help with the first two. SiS GO Isotonic (22 g in 60 ml) and HIGH5 Energy Gel Aqua (23 g in a 66 g sachet) are made to be taken without extra water. The trade-off is bulk: you carry more weight and volume for the same grams of carbohydrate.

• Choose a smaller dose and take it more often. A 22 g gel every 22 minutes is 60 g per hour in gentler steps than a 40 g gel every 40 minutes.
• Single-carb gels such as SiS GO Isotonic and HIGH5 are fine at moderate intakes. Above about 60 g per hour, move to a glucose and fructose blend.
• Maurten says its hydrogel does not need water to go down, and Neversecond says the same of C30. Both are worth a test if thick gels make you gag.
• Caffeine upsets some stomachs. Test caffeinated gels on their own, not on the same day as a new product.
• If gels never sit well even after practice, a mix of drink mix, chews, and real food can carry the same grams. See our guide to moving between gels and real food.

For caffeine

The ISSN position stand supports 3 to 6 mg of caffeine per kg of body weight for performance, usually taken about an hour before exercise. For a 70 kg runner, 3 mg per kg is 210 mg. Caffeinated gels let you spread that dose through the race. The problem is that they range from 20 mg to 200 mg per gel, so two “caffeine gels” can mean 40 mg or 400 mg.

• Low-dose gels (20 to 40 mg) are easy to spread over a race without a big hit at any one time.
• High-dose gels (100 mg or more) suit one planned dose late in the race, if you have tested it.
• Count every source: coffee at breakfast, a pre-race product, and each caffeinated gel. Stay within the amount you have practised.

On a budget

Price per packet hides the real cost, because packets hold different amounts. Divide the price by the grams of carbohydrate. The prices below are box prices on each brand’s own store when this guide was last updated, in the currency of that store. They change often and differ by country, so treat them as a guide to the gap, not a quote.

• Buy boxes, not single gels, once you know a gel works.
• Save your race gel for race-pace sessions and the last few long runs. Easy long runs can use a cheaper gel with similar carbs, as long as you still rehearse the race gel.
• If the race hands out a gel you can tolerate, it saves you carrying and buying a few packets. Our race guides list the course gel for each race.

For real food

Some runners want fewer processed ingredients or simply cannot face another sweet gel. Spring Energy makes gels from fruit, rice, maple syrup, and in some cases nuts. Spring’s own nutrition table shows the trade-off: fewer carbs per packet than most sports gels, and in one case most of the energy from nuts and oil rather than carbohydrate.

At 17 to 19 g per packet, a 60 g per hour plan needs three to four packets an hour, which is a lot to carry over a marathon. Many runners mix real food with a standard gel: real food early when the stomach is calm, simpler gels in the last hour when effort is high. Count the carbs, not the packets, and test the mix on long runs.

Best gels for a half marathon

A half marathon asks less of a gel. Most runners need one to four, and the hourly target is usually 30 to 60 g. That means gel choice is more about comfort and convenience than absorption. A 22 to 25 g gel taken about every 25 to 30 minutes covers most finish times, and a thin gel that needs no water lets you fuel between stations. Runners finishing in about 1:15 or less may not need a gel at all.

• Under about 1:15: no gel, or one before the start or around 25 to 30 minutes in.
• 1:30 to 2:00: two to four gels of 22 to 25 g, the first at about 20 to 25 minutes.
• 2:15 and over: four to five smaller gels, or three to four 30 g gels.
• See our half marathon gel chart for times by finish target.

How many gels you need by finish time

Gel size changes the count. The table multiplies hours on course by a sensible hourly target and divides by the carbs in each gel. In practice you take the first gel about 20 minutes in and stop 20 to 30 minutes before the finish, so the real count is often one fewer. Carbs from a course sports drink also reduce it. For full charts with timing, see our guides on how many gels you need for a marathon and a half marathon.

How to test gels in training

Research on training the gut shows that the stomach and intestine adapt to carbohydrate during exercise when you practise. A gel that bloats you in week one can sit fine by week six. Testing is also how you find out which gel you actually like at race pace, which matters more than any table.

• Pick two or three candidates from the group that fits you. Buy small packs first.
• Test one new gel per long run, not three at once, so you know which one caused a problem.
• Start near your current comfortable intake, often 30 to 60 g per hour, and add about 10 g per hour every week or two.
• Take at least one test gel during a race-pace session. A gel that is fine at easy pace can fail at marathon pace.
• Test caffeine on its own day, at the dose and timing you plan to use.
• If your race hands out a gel, buy a box and test it too. Then decide whether to use it or carry your own.
• Lock in your race gel three to four weeks out. No new gels in race week, including the free one at the expo.

Frequently asked questions

Sources and update notes

1. 1Gel 100Maurten25 g carbohydrate, 0.8:1 fructose to glucose, hydrogel; Gel 100 Caf 100 has 100 mg caffeine; Gel 160 has 40 g carbohydrate; box price
2. 2GO Isotonic Energy GelScience in Sport22 g carbohydrate per 60 ml, maltodextrin, no extra water needed; US price
3. 3GO Energy + Caffeine GelsScience in Sport22 g carbohydrate and 75 mg caffeine per gel
4. 4BETA Fuel GelsScience in Sport40 g carbohydrate, 1:0.8 maltodextrin to fructose
5. 5BETA Fuel + Nootropics GelsScience in Sport200 mg caffeine; one per day
6. 6PF 30 Gel and PF 30 Caffeine GelPrecision Fuel & Hydration30 g carbohydrate; ingredients maltodextrin and fructose; caffeine version has 100 mg
7. 7Energy GelGU Energy Labs21 to 23 g carbohydrate, 60 to 125 mg sodium, 20 or 40 mg caffeine by flavour, maltodextrin and fructose; box price
8. 8Energy Gel Mixed Flavour and Energy Gel CaffeineHIGH523 g carbohydrate per 40 g gel; caffeine version 30 mg; ingredients; UK price
9. 9Energy Gel AquaHIGH523 g carbohydrate per 66 g sachet, caffeine free, no extra water needed
10. 10C30 Energy Gel and C30+ Caffeine Energy GelNeversecond30 g carbohydrate, 200 mg sodium, 2:1 maltodextrin to fructose; C30+ has 75 mg caffeine, no more than one per hour; box price
11. 11What’s In ItSpring EnergyCarbohydrate, sodium, and caffeine per gel for Awesome Sauce, Long Haul, Canaberry, and Speednut
12. 12Nutrition for Athletics: 2019 IAAF Consensus StatementWorld AthleticsRace carbohydrate ranges, up to 90 g per hour for trained runners
13. 13A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During ExerciseSports Medicine (Jeukendrup, 2014), PMID 24791914Multiple transportable carbohydrates and intakes above 60 g per hour
14. 14Training the Gut for AthletesSports Medicine (Jeukendrup, 2017), PMID 28332114The gut adapts to carbohydrate intake during exercise with practice
15. 15International Society of Sports Nutrition Position Stand: Caffeine and Exercise PerformanceJISSN (2021), PMID 333880793 to 6 mg per kg dosing guidance
16. 16Nutrition and Athletic Performance: Joint Position StatementACSM, Academy of Nutrition and Dietetics, Dietitians of Canada (2016), PMID 26891166Carbohydrate intake during endurance exercise