Fuelling Your Runs: A Complete Guide to Running Gels

Running a marathon? Training for your first triathlon? Or maybe you’re just hitting the trails for your weekend long run. Wherever your journey takes you, staying energised is key to finishing strong. That’s where running gels come in—small, carb-packed powerhouses that keep you going when the kilometres add up.

At ASN, we understand the importance of fuelling your body with the right nutrition, especially during endurance events. That’s why we stock a carefully curated selection of running gels, including industry-leading brands like SIS gel, and Endura gel. These gels aren’t just about getting you across the finish line; they’re about helping you perform your best every step of the way. 

Let’s break it down: running gels are carbohydrate-based supplements designed for athletes who need a quick energy boost during long runs, races, or endurance events. Most gels contain a mix of fast-digesting carbs like glucose, maltodextrin, and fructose, which provide your body with instant fuel.

Why are they so popular? Unlike energy bars or drinks, running gels are lightweight, portable, and easy to consume on the move. Just rip open a packet, squeeze, and you’re good to go. They’re also formulated to be easy on the stomach—important when you’re pushing your limits and need something you can digest quickly.

ASN stocks a range of top-performing gels, like Science In Sport (SIS) Go Energy Isotonic + Caffeine Gel , Endura Energy Gel , and the cutting-edge SIS Beta Fuel Gel , which offers a scientifically optimised carbohydrate ratio for maximum energy delivery. Whether you’re racing a 10K or tackling a marathon, these gels are designed to meet the unique demands of endurance athletes.

So, what makes running gels a must-have for serious runners and endurance athletes? Here are a few key benefits:

When you’re hitting the wall, there’s no time to wait for complex carbs to kick in. Running gels provide a quick energy boost to replenish glycogen stores, keeping you fuelled throughout your run.

You don’t need to carry bulky snacks or stop for a meal mid-race. Running gels are designed for on-the-go energy, so you can fuel up without slowing down.

Whether you’re looking for a caffeine boost from SIS Go Energy + Caffeine Gel or need the extra hydration benefits of SIS Go Isotonic Gel , there’s a gel tailored to your specific needs.

The SIS Beta Fuel Gel takes things to the next level with a 1:0.8 ratio of maltodextrin to fructose, proven to increase the percentage of carbs your body can absorb during intense exercise—from 62% to 74%. This means more energy and less fatigue.

Getting the timing right with running gels can be the difference between finishing strong and hitting the dreaded “wall.” The general rule? Start using gels after the first 45 minutes of your run and then every 30-45 minutes afterwards. This keeps your energy levels consistent and helps prevent that sudden drop in performance.

Here’s a guide on how to best use some of our most popular gels:

With 26g of carbohydrates, this gel is ideal for ultra-marathons and long-distance events. The high-carb content makes it perfect for races where you have access to water stations. Take it every 30 minutes with water to stay fuelled and hydrated.

Need a pick-me-up mid-race? This gel provides 22g of carbs and 150mg of caffeine, giving you both a physical and mental energy boost. It’s great for marathon runners or athletes tackling longer distances. Test it during training to see how your body handles the caffeine.

Hydration and energy in one? Yes, please! This gel’s isotonic formula means you can take it without extra water—perfect for short races or intense workouts where you don’t want to worry about hydration.

If you’re an endurance athlete pushing past the two-hour mark, this gel is a game-changer. With 40g of carbs per serving and a unique 1:0.8 ratio of maltodextrin to fructose, it optimises carbohydrate absorption while reducing the risk of gastrointestinal discomfort. Perfect for marathons, triathlons, and long cycling events.

Always practice with your chosen gel during training. You don’t want any surprises on race day, so use your long runs as an opportunity to dial in your fuelling strategy. That way, you’ll know exactly how your body responds and when you need to refuel.

While bars, chews, and drinks all have their place, running gels are often the go-to for serious endurance athletes. Why? Because they offer fast absorption, are easy to carry, and don’t require chewing—perfect when you’re in the middle of a race and need an instant energy boost.

Another key advantage of running gels is their lack of fibre, compared to energy bars or snacks. High-fibre foods can slow digestion, which may lead to gastrointestinal discomfort during a race—something every athlete wants to avoid. Bars and chews also require more effort to break down, which can be especially taxing when you're already pushing your limits.

In fact, chewing itself consumes energy. It may seem like a small task, but when you’re running a marathon or cycling for hours, every bit of energy counts. Running gels eliminate this extra expenditure by offering a smooth, quick-to-consume option, allowing you to focus solely on your performance, not digestion.

Incorporating running gels into your training and race-day strategy can make a world of difference in how you perform and recover.

ASN has the perfect solution to meet your endurance needs. Whether you’re training for a marathon, tackling a triathlon, or pushing through an ultra, the right gel can keep you energised and focused from start to finish.

Ready to fuel your next adventure? Explore our Running & Endurance Collection online to find the perfect energy gels for your race. Prefer in-person advice? Visit your nearest ASN store, where our experts are ready to help you choose the best products for your goals and get you race day ready.