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The Healf Source
The Science Of High-Carb Fuelling, And How To Build Up To It
New fuelling technology has rewritten what's possible in endurance sport — provided the gut can keep up. Here's the science behind it, and where Maurten's Gel Mix 480 fits in.
Written by: the Healf Editors
Written on: September 2, 2026
Ask any endurance athlete where a race is won or lost, and most will point to the legs or the lungs. But our biology and physiology tell a different story. The real ceiling on performance sits lower down — in the gut. An athlete can build enormous aerobic capacity over seasons of training and still come undone on the day, not for want of physical capacity but because their body is burning through fuel faster than they can consume more. Cramps, nausea, the slow fade of running on empty: the limiting factor during your marathon PB attempt becomes your body's ability to absorb carbs in the moment, while under stress.
This is where Maurten Hydrogel Technology comes in. It tackles the fundamental fuelling problems that limit performance head-on, using hydrogel technology that makes high concentrations of carbohydrates more tolerable during high-intensity training and racing. And the results speak for themselves — you’ll find Maurten hydrogel fuels behind the fastest marathon times in history, multiple world records, world champions, and gold medals.
Fuelling basics
To maintain performance, endurance athletes require carbohydrates — the most efficient source of fuel for the body. The greater the load — exercise intensity, duration, or frequency — the more carbohydrates are required.
The body already holds a finite reserve of fuel in the muscles and liver, and it starts drawing on it the moment an athlete begins to move. As the session or race wears on, that reserve depletes, until eventually there isn't enough left to sustain the effort, even if that person has the aerobic capacity for more. The further you go and the longer you're pushing, the more fuel — which comes from carbohydrates — you need. But there's a catch.
During exercise, blood is diverted away from the stomach to supply the working muscles. Digestion becomes harder at precisely the moment you're asking more of it, and the risk of gastrointestinal (GI) discomfort rises.
Maurten sports fuels are designed to optimise the delivery and absorption of carbohydrates during exercise, while staying gentle on the gut. Stomach aches and nausea can quickly derail a race or a training session, but Maurten Gels, Drink Mix, and the new Gel Mix 480 all harness Hydrogel Technology to reduce the risk of GI distress, which naturally makes that refuelling period much easier and more effective. By encapsulating the carbohydrates in hydrogel, the fuel is protected from stomach acid and carried through to the intestines where they can actually be absorbed.
Get used to it
Elite marathon runners and cyclists now target 100 to 120 grams of carbohydrates per hour. And while high-carb fuelling can have a dramatic impact on performance at every level, it is something you need to slowly work up to. Building tolerance matters: fuelling is not a skill you save for race day, which means you train the gut alongside the legs and lungs. By rehearsing your race-day fuel in training, you get used to the sensations and the logistics while priming your gut to absorb more carbohydrate on the move. Research indicates that training the gut with measured amounts of sports nutrition reduces the likelihood of gastrointestinal distress on race day.
Frequency matters too. A sustained block of regular training is physically demanding, and recovery should begin before you finish a session. Holding an appropriate fuelling strategy right to the end keeps the body from finishing in a depleted state. Feeling tired is appropriate — feeling empty is not.
Take it personally
Fuel with the same products often enough and flavour and texture fatigue start to bite. Maurten hydrogel fuels come in three formats to work around that. The Gel is a single-serve, semi-solid sachet. The Drink Mix is a liquid that converts to a gel in the stomach. And Gel Mix 480 is a third consistency that also forms a stronger hydrogel once it's there. Its soft, flowing texture pairs with a soft flask to deliver up to 120 grams of carbohydrates per serving. Take it all in one session or keep it in the fridge to fuel more training — either way, Gel Mix provides athletes of all levels with better fuelling support, flexibility, and control.
Flavour fatigue is a real thing when you're using the same fuel week in, week out — so you can mix the Gel Mix with Maurten Additions to keep it interesting: Cola, Menthol, Orange, or Apple.
Mixing up texture and taste — while still getting the benefit of Hydrogel Technology — makes it easier to stick to your fuel plan. And the more sessions you fuel properly, the better your recovery, adaptation, and results.
This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Healf
Healf's editorial team works hard to produce science-backed, expert-vetted stories to break down trends and cut through the noise in the wellbeing ecosystem. Our team of writers and editors specialise in everything from nutrition, to exercise science, women's health, skincare, sleep, and more.
