Energy gels are widely used in sport, from tennis to cycling and rowing to football. As a quick, convenient source of carbohydrate, energy gels have become a go-to of elite athletes as part of their performance nutrition strategy. But how do energy gels work? Science in Sport recently sat down with Dr Emily Jevons to get the low down on the science behind energy gels. What Do Energy Gels Do? When cycling, for example, your body will primarily use two different fuel sources depending on the intensity and duration of your ride, carbohydrate and fat. Whilst our fat stores are often more available than our carbohydrate stores, fats are slower to break down into usable energy. Carbohydrates can be broken down much quicker than fat stores, as a general rule of thumb the faster you ride, the more your body will fuel through your carbohydrate stores. Carbohydrates are mostly stored as glycogen within the muscle and liver with some circulating in the blood as glucose. However, your body can only store so much carbohydrate (this will vary between individual depending on body mass, diet and training status), meaning we need to top up our energy stores with external carbohydrate sources. Energy gels provide a quick accessible solution that can be used on the go, providing 22-40g of carbohydrate per gel depending on which type of gel you choose. Consuming these carbohydrates will maintain your blood glucose levels and hopefully prevent fatigue allowing you to ride at your best for longer. What makes an energy gel better than generic carb/fat-rich snacks? When you need energy fast, energy gels provide a quick, easy-to-digest and convenient supply of energy. They can be used as part of your fuelling strategy without the excess liquid volume which can leave you feeling bloated. They also come in practical packaging which can easily fit in the back of your jersey or in a nutrition box on your top tube. Energy gels often also contain other additional ingredients to aid performance that you won’t find in generic carbohydrate heavy snacks. For example, electrolytes, caffeine or nootropics. Electrolytes are often added to aid hydration by replacing the electrolytes we lose when we sweat. Caffeine and nootropic (substances to aid with cognitive enhancement) additions are used to provide that mental boost and are especially beneficial toward the end of a race or ride. Are there any downsides to using energy gels? You need to have time to practice with them before an event, both in terms of practicality and to give your gut time to get used to them. You should never try anything new on race day, so if you’re reading this article and racing next weekend it’s probably not the best time to put energy gels in your fuelling strategy! Practice using them on training rides or on the turbo first. The market is also highly saturated now, so it can be hard to identify which energy gel would be best for you. Not everyone’s stomach can handle energy gels which can lead to some gastrointestinal distress but try to use the energy gels that don’t require you to also drink water (i.e. Science in Sport GO Isotonic Energy Gels). With other gels, you might find them to be thick and sticky. What differentiates isotonic gels from other energy gels? The tonicity of a solution is referring to the concentration affecting water and carbohydrate transportation across our cell membranes and importantly, the movement from our gut and into the bloodstream, which will ultimately affect how quickly we can use the energy gels we have just consumed. Solutions can be classed as hypertonic, hypotonic or isotonic. For a solution to move easily through our cell membranes it needs to be isotonic, this means the solution has the same concentration as the fluid within our cells meaning the risk of gastrointestinal discomfort is much less! Traditional energy gels often advised you to consume water alongside the energy gel, as otherwise it can’t be absorbed quickly and efficiently do its job! The Science in Sport GO Isotonic Energy Gel was the world’s first isotonic gel providing 22g of carbohydrate. As the gels are isotonic, they can be consumed without water, this helps minimise the risk of bloating or general gastrointestinal discomfort which can sometimes occur with over-drinking. Since developing their first isotonic energy gel, Science in Sport have continued to develop numerous gels in different flavours and different concentrations of carbohydrate, including their recently optimised high-carbohydrate (40g per gel!) Beta Fuel range. To find out more about Science in Sport’s range of energy gels, click here. Written By Kimberley Bull - Brand Manager Kim joined the SiS team in 2021 and has a long-standing passion for team sports. She started out as a broadcast assistant and match summariser at the BBC and has gone on to work with brands, teams and organisations to engage audiences in the world of sport. Outside of work, Kim is a supporter of digestive health charity, Guts UK, and will take on the London to Paris Bike Ride in July 2022 to raise funds.