Fuel Guide
Plan your fueling for one session, a race or your regular training.
How many carbs per hour do you need?
During endurance exercise, your body runs largely on carbohydrate. You store roughly 400 to 600 g of it as glycogen in your muscles and around 100 g in your liver. That tank is limited. The emptier it gets, the heavier your legs feel and the harder it is to stay focused. At worst, you hit the wall, or bonk: your stores are close to empty and your performance suddenly drops off. Carbs during the session keep your blood glucose steady. That makes your stores last longer.
Carbs often get a bad rap in everyday eating. In endurance sport, they are what keeps your pace up. In a large cycling study, performance rose with intake, up to about 80 g per hour. In elite mountain runners, 120 g per hour led to less muscle damage than 60 or 90 g. For you, that means holding quality for longer, an easier last hour and better recovery.
Still, there is no single number. For shorter sessions, reasonably full stores are usually enough. For long efforts, the guidelines recommend up to 90 g per hour, from glucose and fructose together. With a trained gut, many athletes get to 120 g or more. Two patterns come up a lot. Either easy sessions get too little and you finish flat. Or intake jumps to very high amounts before your gut is ready.
The RocketFuel Fuel Guide turns all of this into your personal plan. It works with your duration, intensity, gut tolerance and conditions. You get grams per hour and which gel to take when, plus sodium and fluid. These are starting points, not rules. Use them to build up step by step in training.
That is also why we built three gels instead of one for everything, after asking 6,457 endurance athletes how they fuel. TRAIN (25 g, 2:1) is built for lower to moderate carb targets. Part of its carbohydrate is isomaltulose. It is fully digested, just more slowly. So the energy comes in more evenly, and the gel tastes less sweet. RACE (40 g, 1:0.8) is built for 90 to 120 g per hour and above, with fewer gels to get there. The highly branched cyclic dextrin in RACE is a very large molecule. Fewer dissolved particles pull less water into your gut. So the gel sits lighter, even at high intake. RACE+ adds caffeine, L-theanine and taurine to RACE.
How your gut absorbs carbohydrate, what 2:1 and 1:0.8 mean and how to train your gut: we explain it with 31 sources on our page about the science behind the gels.
Any questions?
Reach out, we are happy to help with your strategy.
General guidance for healthy adults, not medical advice. Carbohydrate tolerance is trainable and individual: build up gradually and test everything in training before you use it in a race. RACE+ contains caffeine, max 4 per day. More on the science behind it