The 2026 London Marathon witnessed a remarkable milestone when Sebastian Sawe tore open a carbohydrate gel sachet just five minutes before the race began. After a mere hour, he consumed another gel, propelling him through the sub-two-hour marathon barrier.
Although Sawe became the first runner to break this impressive record, he isn’t the first to harness the power of energy gels. In fact, it’s estimated that over 70% of marathon runners utilize gels for energy during competition.
Long before the advent of energy gels, endurance athletes relied on a variety of foods to sustain their performance. Options ranged from sugar cubes and coffee to chocolate, beer, wine, and even egg whites and brandy.
Beginning in the 1970s, scientific research began to align with these athletic practices. Studies showed that carbohydrates were effective for fueling prolonged endurance exercise, with foods containing glucose and fructose identified as the most effective energy sources.
Owing to decades of research, athletes now have access to energy gels—scientifically formulated carbohydrates crafted from maltodextrin and fructose blends, encased in a hydrogel.
Despite the advantages of modern gels, not all experts are convinced they deliver on their promises. For many athletes, these gels can also result in uncomfortable side effects.
This raises an important question: Are gels genuinely beneficial, or should athletes consider simpler, albeit less glamorous, alternatives for fueling their performance?
Fuelling with Energy Gels
When we consume a meal, our bodies gradually break down carbohydrates in the stomach. These carbohydrates convert into glucose (a simple sugar) that enters the bloodstream.
Glucose is then transported to the muscles and liver, where it is stored as glycogen, allowing for easy energy access during physical activity.
However, glycogen stores typically deplete within about 90 minutes. When this occurs, athletic performance can suffer, which is why endurance athletes often need to consume carbohydrates during lengthy races or training sessions.
In practical terms, energy gels provide a rapid, convenient, and concentrated source of carbohydrates that can be consumed on-the-go. Compared to whole food options, they are easier to digest and dosed precisely, helping runners maintain a consistent energy level.
However, this convenience comes with a price. Energy gels can be costly, some athletes may find them unappealing, and they are frequently linked to gastrointestinal distress, especially when consumed in large quantities or without enough hydration.
Alternative options like sports drinks or sugary snacks may offer similar energy levels, but they often lack the convenience and specific dosing found in gels.
Research indicates that there’s significant variation among different gel products. A survey of 31 gel product ranges (covering 51 flavors across 23 brands) identified wide discrepancies in serving size, carbohydrate content, free sugars, and especially osmolality (the concentration of a solution). This varied composition can influence how and when gels should be used and their effects on performance.
Moreover, gels may not provide any unique advantages over other fueling options such as sports drinks.
A 2010 study revealed that gels and drinks transport carbohydrates to the muscles at equivalent rates. This conclusion was later reinforced by a 2022 study, which found no significant differences in benefits from gels, drinks, or chews.
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Ultimately, the main advantage of gels lies in their convenience, easily stored and consumed while running.
That said, gels may not be without their drawbacks. Gastrointestinal distress is a commonly reported issue, affecting approximately 10-20% of users, according to one study.
Hydrogel drinks and products create gels in the stomach, aiming to minimize the amount of water crossing the intestinal barrier. This approach is intended to reduce bloating and cramping while enhancing carbohydrate absorption into the bloodstream.
However, studies have not consistently demonstrated improved performance or reduced gastrointestinal distress compared to standard carbohydrate sources, even when calories remain consistent.
Due to their concentrated nature, gels migrate to the small intestine, where their sugar concentration may exceed that of surrounding blood and tissue. This can lead to water being drawn into the gut, which could contribute to bloating and cramping unless consumed with adequate hydration.
How to Use Gels Effectively
If your workout lasts under 60 minutes, gels are probably unnecessary.
For runs lasting 60-90 minutes or more, aim to refuel before you feel depleted. A target of 30-60g of carbohydrates per hour is advisable.
Even if you don’t feel hungry, try to consume small, regular amounts of carbohydrates—like a few sips or half a gel every 15–20 minutes—to maintain energy levels and stave off fatigue.
During longer races, aim for about 60-90g of carbohydrates each hour. A combination of glucose and fructose may be particularly beneficial when running at higher intensities.
Testing gels during training is crucial; don’t wait until race day to try them for the first time. This allows you to determine how well your body tolerates them and whether they enhance your performance.
Some runners are more susceptible to gastrointestinal issues, so switching brands can make a difference if you’re affected.
If gels consistently cause discomfort, consider reverting to traditional fueling methods—like bread, fruit, sugar cubes, bananas, dates, and rice cakes. Just remember to practice with these foods during training to observe their effects on your body.
While these alternatives may work well at lower intensities, gels persist as popular options because they offer standardized dosages and are convenient for quick consumption.
