Effort-matched fueling.
Easy session, hard intervals, race day: not every effort needs the same fueling. Let's make fueling more intuitive, not more complicated. This page explains how our gels work, what is inside and the studies behind it.
Tap a gel to jump straight to its section.
01
Not every session has the same fueling demands. An easy endurance session does not need the same carbohydrate intake as a long, demanding one, hard intervals or a race. And plenty of athletes want caffeine at specific moments rather than in every gel.
Most athletes will recognize one of these two: they underfuel easy sessions, finish flat and recover slowly. Or they jump from very little to very high carbohydrate intake before their gut is ready, and pay for it with stomach trouble.
So we surveyed 6,457 endurance athletes across sports and performance levels on how they actually fuel. Almost nine in ten fuel hard efforts differently from everyday training. So instead of building one gel to cover every situation, we built three and matched each one to a different kind of effort.
Our goal: make fueling more intuitive. You reach for the gel that fits the effort ahead: more carbohydrate for hard and long efforts, less for easy ones. The decision is made before you leave the house. And if you want to, you can still plan your intake with TRAIN, RACE and RACE+ down to the gram.
TRAIN, RACE and RACE+ are named after the effort they were built for, not after when you are allowed to use them. RACE means high intensity and high-carbohydrate fueling, whether that is a race or the hardest session of your week. TRAIN means lower to moderate carbohydrate targets, in training and on race day alike. What matters is intensity, duration and your planned intake.
02
Every RocketFuel gel is built on maltodextrin and fructose. That is the standard base in endurance nutrition, and for good reason.
Glucose and glucose-type carbohydrates (maltodextrin is a chain of glucose units) are absorbed mainly through a transporter in the intestinal wall called SGLT1. Think of it as a doorway with fixed capacity: at roughly 60 g per hour it is working at its limit. Anything beyond that gets through more slowly, sits in your gut longer, and can cause bloating, cramping or nausea.
For a long time that was the ceiling in the guidelines: around 60 g per hour, more was thought to go to waste. Then studies showed that fructose uses a completely separate doorway, GLUT5, and that glucose plus fructose lets you absorb and use considerably more carbohydrate. The guidelines were updated: for long efforts they now recommend up to 90 g of carbohydrate per hour, provided it comes from multiple sources, meaning glucose and fructose.
One important detail: fructose on its own, in large amounts, is poorly absorbed. Taken together with glucose it is absorbed almost completely. That is why every one of our gels pairs the two. What matters in the end is not how much carbohydrate you eat, but how much of it is absorbed, tolerated and actually used for energy. Sports scientists call that the oxidation rate.
Maltodextrin and fructose do the heavy lifting in every RocketFuel gel. On top of that base, each gel gets a third carbohydrate chosen for the job that gel has to do: , . More on both below.
Illustration for explanatory purposes
03
The carb ratio is simply how a gel's carbohydrate splits between glucose-type sources and fructose. 2:1 means two parts glucose-type to one part fructose. 1:0.8 is close to half and half. The ratio matters because the two sides use different transporters. It helps decide how much you can absorb per hour and how the gel feels.
At 60 to 90 g per hour SGLT1 still has capacity, so leaning toward glucose-type carbohydrate delivers the energy quickly. The fructose is still there so GLUT5 gets used too, but deliberately in a smaller share: less fructose per gel means less sweetness and, for most people, a gel that is easier to keep taking across a long session. There is another reason: if you are not used to high carbohydrate or fructose intakes in everyday life, the smaller fructose share is usually much better tolerated in everyday training.
The glucose door is full at about 60 g per hour. At 2:1 you reach those 60 g of glucose-type carbohydrate at 90 g of total intake. To take in more, you need a higher fructose share so the second transporter comes properly into play. In studies at high intake rates, ratios around 1:0.8 led to more of the ingested carbohydrate being used than 2:1, with gut comfort at least as good, and 120 g per hour has been studied with exactly this ratio. That is what makes 120 g per hour or more realistic rather than theoretical, given a trained gut.
Why we quote the ratio of the finished gel. Maltodextrin and cyclic dextrin are glucose-only. Isomaltulose is built from one glucose and one fructose unit, so it counts on both sides. The ingredient list alone does not tell you what a gel actually delivers. Calculated across every carbohydrate source in the formulation, TRAIN lands at 2:1 and RACE and RACE+ at 1:0.8.
Not everyone needs 1:0.8, and not every session needs 90 g per hour or more. Higher intakes need a trained gut.
Lower fructose, less sweet, quick delivery at 60 to 90 g per hour.
Both transporters in full use at 90 to 120 g per hour and beyond.
04
TRAIN · Everyday Fuel
TRAIN is built for lower to moderate carbohydrate targets: easy to moderate sessions, steady endurance work, and fueling strategies of around 60 to 90 g per hour. It also works as a quick top-up before a shorter session when your stores are not full, when you feel a bit flat, or when you are training on an empty stomach.
Isomaltulose is a disaccharide made of glucose and fructose, found naturally in small amounts in honey and sugarcane. The two units are bonded differently from the way they are in table sugar, and that bond takes longer to break. So isomaltulose is fully digested, just more slowly. In TRAIN it makes up 20% of the carbohydrate, 5 g per gel.
That does not make TRAIN a slow-release gel. The majority of the carbohydrate is still maltodextrin and fructose, so you get the fast, immediately available energy you would expect from any gel. The isomaltulose adds a slower-releasing portion alongside it, which makes the overall delivery more sustained. For a long, steady session that is exactly the right profile. It brings two other things with it: it is noticeably less sweet than table sugar, and because it contains glucose and fructose in equal parts it feeds into the overall 2:1 ratio.
What the research shows: the slower digestion is well established and produces a flatter blood glucose curve. In exercise studies, isomaltulose produced smaller blood glucose fluctuations and better-maintained blood glucose later in prolonged efforts compared with maltodextrin. How energy feels still varies from athlete to athlete.
Based on customer and athlete feedback
Illustration for explanatory purposes
05
RACE · High Carb Performance
RACE is built for higher carbohydrate targets: hard training, long demanding sessions, races, and strategies of 90 to 120 g per hour and above. With 40 g of carbohydrate per gel you need fewer gels to get there. And RACE is not just for race day. Use it deliberately in training, especially in the weeks before an important event, so your gut practices the exact intake and product you plan to use on the day. And if you fuel at 90 g per hour or more in training anyway, RACE can simply be your everyday gel.
Highly branched cyclic dextrin, or HBCD, is a very large carbohydrate molecule made from starch. Molecule size is given as molecular weight in Daltons, the weight of a single molecule. Typical maltodextrin sits at around 1,000 to 4,000 Daltons. HBCD sits at around 150,000 Daltons, and higher depending on the manufacturer's data. So HBCD is roughly 50 to 100 times the size of maltodextrin.
When you swallow a concentrated carbohydrate solution, your gut dilutes it by drawing water out of your body and across the gut wall until the concentration is balanced. That water is missing elsewhere, it delays stomach emptying, and a stomach full of fluid is exactly what makes a gel sit heavy. Concentrated, strongly osmotic carbohydrate solutions are one of the recognized triggers of gut trouble in endurance sport.
How much water gets pulled in depends on the number of dissolved particles, not the number of grams. Scientists call this osmolality. Because HBCD packs so many glucose units into one molecule, the same amount of carbohydrate dissolves into far fewer particles than simple sugars, and fewer than maltodextrin. Less water pulled in means the gel sits lighter. And in a study of carbohydrate drinks, HBCD solutions left the stomach faster than conventional dextrin solutions. Both of those help most when you are taking in a lot of carbohydrate at high intensity.
We narrowed in on that proportion step by step during development. A higher HBCD content changes a gel's texture over time, and not for the better. We tested gels from other brands built on 100% HBCD and they were grainy, heavy and sticky in the mouth. We wanted a gel that is slightly runny without being watery, easy to swallow without interrupting your breathing at intensity, and the same after months on a shelf. At 10%, low osmolality, a pleasant consistency and long-term stability came together.
Together with the ratio, the sodium and the water content, HBCD gives you a gel that goes down easily and stays easy on the stomach when you are taking in a lot of carbohydrate under hard effort.
Based on customer and athlete feedback
Illustration for explanatory purposes
06
RACE+ · Focus Boost
RACE+ has the exact same carbohydrate and electrolyte formulation as RACE and adds a focus stack of caffeine, L-theanine and taurine for moments when alertness and focus matter too: the final hour, the run-in to the finish, or simply a day when you are tired and need a push to get going.
One of the most consistently supported performance aids in endurance sport. It lowers perceived effort and sharpens alertness. Tolerance varies a lot, though, and is partly genetic: some athletes feel sharp and steady, others jittery. Test it in training first and treat it as a tool, not a requirement.
An amino acid from tea, very commonly paired with caffeine. In studies the combination improved attention and alertness beyond caffeine alone, and many people describe it as smoother: the focus you want, with less of the restlessness often associated with caffeine on its own. RACE+ pairs the two 1:1, 100 mg of L-theanine to 100 mg of caffeine, a common dosing for this combination.
An amino acid your body makes itself and a frequent ingredient in caffeine-based performance formulas. A meta-analysis of ten studies found taurine improved endurance performance, and research into its role in sport keeps growing. In RACE+ it rounds out the focus stack alongside caffeine and L-theanine.
Use it deliberately. The labeled maximum is 4 RACE+ gels per day, which is 400 mg of caffeine from the gels alone, before coffee, tea, cola or energy drinks. EFSA, the European Food Safety Authority, considers up to 400 mg per day safe for healthy adults, and single doses of up to 200 mg as well. Those are population figures, and they cover caffeine from all sources combined. How caffeine feels depends on body weight, habitual intake and genetics. What works for you, you find out in training, not on race day. For most athletes RACE+ makes more sense used strategically at the moments that matter rather than as the only gel across a long session. Not recommended for children or during pregnancy and breastfeeding. If you need or prefer to avoid caffeine, RACE is identical apart from the caffeine, L-theanine and taurine.
Based on customer and athlete feedback
Toward the finish
Full focus from the start
Many save the caffeine for later, when alertness and concentration start to matter. Others take it right at the start to be fully there from the first minute, or simply because they are tired. Some do both. In our customer feedback, 60% used RACE+ during a hard session, 48% late in a race or hard session and 34% when they felt low on energy.
07
Sodium is by far the electrolyte you lose most when you sweat. A liter of sweat carries roughly 500 to 1,800 mg of sodium, and endurance athletes sweat about half a liter to two liters per hour depending on intensity, heat and the individual. That means anywhere from around 250 mg to well over 2,000 mg of sodium per hour. Potassium, calcium and magnesium are lost too, in much smaller amounts. The longer, harder and hotter the session, the more you sweat, and the more of everything in it you lose. Sodium is then not the only electrolyte worth replacing.
TRAIN carries 200 mg of sodium per gel. RACE and RACE+ carry 250 mg of sodium plus calcium, magnesium and potassium. The logic is the same as with the carbohydrate: the gels built for the hardest and longest efforts bring more sodium and add the other electrolytes, because that is exactly where the losses are highest.
That makes your fueling and hydration strategy more flexible. You are not relying on the electrolytes in your bottle alone: if it runs low, if you can only top up with plain water, or if you are out without an electrolyte mix, your gels are still bringing sodium with them. Two RACE gels an hour bring 500 mg. At a moderate sweat rate that covers a large part of the hour's loss for many athletes. Heavy sweaters and hot days top up from the bottle or other sources.
Most of the sodium comes from sodium citrate, the rest from sodium chloride, which is ordinary table salt. Sodium chloride is also the form in which you lose sodium through sweat. Sodium citrate brings two advantages. It tastes far less salty for the same amount of sodium. And many athletes find it easier to tolerate than plain salt. The reason is the same as with cyclic dextrin: one molecule of sodium citrate carries three sodium ions, table salt only one. For the same amount of sodium, fewer dissolved particles end up in the gel, and fewer particles means less water pulled into the gut to dilute it. On top of that, citrate buffers the acidity of the gel. That is how the gels can carry a meaningful sodium dose without tasting salty, and stay easy on the stomach.
| Electrolyte | per liter of sweat |
|---|---|
| Sodium | 500 – 1,800 mg |
| Chloride | 700 – 2,500 mg |
| Potassium | 80 – 310 mg |
| Calcium | 8 – 80 mg |
| Magnesium | 0.5 – 10 mg |
Typical ranges per liter of sweat, after Baker 2019.
| TRAIN | RACE / RACE+ | |
|---|---|---|
| Sodium | 200 mg | 250 mg |
| Other electrolytes | – | Calcium, magnesium, potassium |
| Sodium source | Mostly sodium citrate, topped up with sodium chloride (table salt) | |
08
That depends on how long and how hard you are going, and how used to high carbohydrate intake your gut already is. These are starting points, not rules.
| Duration / effort | Carbs per hour | Where our gels fit |
|---|---|---|
| Under 60 minutes | Not strictly needed | One TRAIN before the start as a top-up if you want to begin with energy available |
| 1 to 2 hours | 30 to 60 g | 1 to 2 TRAIN (25 to 50 g), plus a little from your bottle if needed |
| 2 hours and beyond | 60 to 90 g | 2 TRAIN plus a drink mix or other sources, or 2 RACE (80 g) |
| Long or hard efforts | 90 to 120+ g | 2 to 3 RACE (80 to 120 g from gels alone). Swap in RACE+ where you want the caffeine, within the daily maximum |
TRAINbefore the start
TRAIN
TRAINif needed
RACE
RACE
or 2 TRAIN plus a drink mix or other sources
RACE
RACE
RACE+where you want caffeine
Schematic, one hour on the move. Amounts and alternatives are in the table.
Your ability to absorb and tolerate high carbohydrate intake is trainable. A sustained higher intake increases the density and activity of the SGLT1 transporters in your intestine, and a 28-day study measured a real rise in how much ingested carbohydrate athletes could use. Structured exposure has also been associated with fewer gastrointestinal symptoms at high intake rates. Build over weeks, not days, practice under conditions similar to your event, and never use a new product or a higher carbohydrate intake for the first time in competition.
The slightly runny consistency is there so the gels go down easily even without water. A few sips right after are still worth it, especially with several gels or a high carbohydrate intake: water helps move the carbohydrate along and keeps the concentration in your gut lower.
You might use TRAIN through the easier part of a long session and switch to RACE as the intensity or carbohydrate target climbs, and combine either with a drink mix or other sources. What counts is the total across the whole session, and that you have tested the combination in training before you rely on it at an important event.
Not sure which gel to choose?
Get your fuel guide →09
What we leave out, what we insist on, and who checks.
The sweetness comes from the fructose, the flavor from natural flavorings: red fruits in TRAIN, lemon in RACE and RACE+. We do not use dextrose or sucrose: both are very sweet and, being small molecules, push up the osmolality of the gel, which puts unnecessary stress on the stomach. Maltodextrin, isomaltulose and cyclic dextrin all taste far less sweet. Sweeteners and sugar substitutes stay out for another reason too: they can upset some people's stomachs.
No ingredient of animal origin, and none of the 14 allergens that have to be declared in the EU (gluten, milk, nuts, soy and the rest) goes into the recipes. Because no production line can rule out cross-contact 100%, the label says "not intentionally used". If you have a serious allergy, check the pouch of your batch.
Produced under the strictest food safety standards, in small batches, and shipped from our warehouse in Germany. Small batches means every one is checked, and the quality stays the same after months on the shelf.
All RocketFuel products are officially listed on the Cologne List® and have been tested for selected doping substances, without objection. The program combines product testing with manufacturer disclosures to help minimize the risk of contamination with substances prohibited in sport. You can look up product and batch directly in the Cologne List® database.
10
During development we tested more than 50 gels from other brands, and not at a desk but where it counts: can you open the pouch one-handed on the bike? Does the gel still go down in hour three, when your stomach has long turned sensitive? What is the texture like after months on a shelf? Most of them were fine. But almost every one was lacking somewhere: taste, texture, ingredients or packaging.
Those tests are exactly where the details that define RocketFuel come from: the tear tab that stays attached. The slightly runny texture that goes down between two breaths. The 10% cyclic dextrin that keeps the gel easy to tolerate even at high intakes. If "fine" is enough for you, there are plenty of gels that will do. RocketFuel is built for athletes who want the whole experience right: a gel you still look forward to late in a long session, that stays quiet in your gut and delivers exactly the energy the effort asks for. No compromise, no sugar-syrup feeling, nothing to think about.
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 TRAIN |
 RACE |
 RACE+ |
|
|---|---|---|---|
| Built for | Everyday Fuel: easy to moderate sessions, 60 to 90 g/h | High Carb Performance: hard efforts, long demanding sessions, races, high carb intake | Focus Boost: decisive moments, when focus matters too |
| Carb target | around 60 to 90 g/h | 90 to 120+ g/h | 90 to 120+ g/h |
| Carbs per gel | 25 g | 40 g | 40 g |
| Carb ratio | 2:1 | 1:0.8 | 1:0.8 |
| Base | Maltodextrin + fructose (in all three) | ||
| Third source | Isomaltulose (20%, 5 g) | Cyclic dextrin (10%, 4 g) | Cyclic dextrin (10%, 4 g) |
| Sodium | 200 mg | 250 mg | 250 mg |
| Other electrolytes | – | Calcium, magnesium, potassium | Calcium, magnesium, potassium |
| Caffeine | – | – | 100 mg, plus 100 mg L-theanine and 500 mg taurine |
| Flavor | Berry | Lemon | Lemon |
| Volume | 50 ml | 70 ml | 70 ml |
TRAIN
RACE
RACE+
Not sure which gel to choose?
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