I've Run 947km This Year Already—5 Best Running Gels For Seamless, Supercharged Miles

They say you never forget your first marathon, and I'll certainly never forget mine - the London Marathon 2018. It was 28 degrees, despite us having trained in snow, sleet, and hail; the crowds came out in their thousands; and I completed a distance that 24 hours prior, I wasn't entirely convinced I'd be able to finish.

For a first timer, I got so many things right that day: I'd prepared my body for the distance by ticking off nearly every training run, I'd tested my kit again, and again, and again in training to ensure nothing chafed or caused discomfort, and I had an unforgettably good playlist. But one thing I didn't quite nail? My fuelling.

As a woman who grew up in the Special K diet generation, constantly being told to shrink ourselves and eat less, I'd convinced myself that I didn't "need" as many gels as sports dietitians recommended and that I'd be A-okay just powering through.

And sure, I made it to the end in one piece, but two carb gels for a 4-hour marathon did teach me a very simple life lesson: if you're doing endurance sport, where you're depleting your body's energy stores, you need to be returning that energy in real time. Or you'll end up like me at mile 20 of my first one: tackling the dreaded wall with all my might and clinging on for dear life.

As more and more people globally get into running, I've made it my mission to spread the fuelling message and importance of giving your body what it needs far and wide. Which is why, below, I've deep dived into my all-time favourite fuelling brands and gels, with helpful insights from Dr Jamie Pugh, Scientific Advisor at Puresport and Co-founder of ExoAnalytics.

Ready to fuel your best runs yet? Keep scrolling.

What is a running gel?

Let's start at the beginning, for those of you who've heard the term bandied around but aren't familiar with what a gel actually is. According to Dr Pugh, "Carbohydrate gels are a concentrated source of simple, easy-to-digest sugars (like glucose, maltodextrin, or fructose) made up into sachets in a gel-like texture."

If you're running, cycling, or doing endurance sports for 45 minutes or more, their purpose is simple: to supply fast-acting carbs that, once consumed, are rapidly absorbed and converted into usable energy.

"Many gels have as much carbohydrate as an entire bottle of sports drink - helping you to fuel without needing to carry lots of extra weight or drink too much fluid," he goes on.

Why do we need gels?

As I touched on in my intro, because when we workout for long periods of time (think 45 minutes or more), our body starts to rely on carbohydrate (glycogen) stores to fuel our mileage. "However, stored carbohydrate is limited and can begin to run low within 60-120 minutes of sustained effort," Dr Pugh explains. "As this happens, blood glucose levels can fall, muscles have less readily available fuel, and exercise starts to feel harder - often described by runners as ‘hitting the wall’."

That's where gels come in - a simple and convenient way to boost your carbohydrate stores and energy levels, providing an immediate energy source for your muscles.

Are gels science-backed?

In a nutshell - yes, and extensively. One landmark review by sports nutrition researcher Asker Jeukendrup concluded that carbohydrate intake during endurance exercise both improves performance and delays fatigue, especially in events lasting longer than an hour, and there's been plenty of research proving the same sentiment since.

"Research has shown again and again that taking on carbohydrates during exercise helps us maintain pace, makes it feel easier to run at the same pace, delays fatigue, and improves performance," Dr Pugh concludes.

Are gels essential?

According to Dr Pugh, they’re not strictly “necessary” for short efforts, but become increasingly important as duration and intensity rise. "Some of the first research ever looking at carbohydrate and long-distance running took place over 100 years ago at the Boston Marathon, where it was shown that consuming sources of simple sugars during the race helped runners maintain their blood glucose levels," he goes on.

If you'd rather opt for more natural sources of energy, like bagels or bananas, make sure you try it in training - each fuel type has it limitations. "Whole-food options like bananas or energy bars contain fibre and solid food parts that are slower to digest, especially during exercise," Dr Pugh. "Sports drinks, on the other hand, require larger volumes of fluid to deliver the same amount of carbohydrate. These factors can make these options more likely to cause digestive issues like bloating and stomach fullness."

Gels, on the other hand, aim to avoid these issues by "delivering a high amount of carbohydrate in a small, concentrated format that’s easier to tolerate." Speaking from personal experience, they're also super practical - easy to carry, lightweight, and simple to open when you're mid run.

As a general rule of thumb, aim for 30–60g carbs an hour.

How many should I take and when?

There is a lot of advice on how many gels to take. Some of the world’s fastest athletes will take anywhere up to 4 or 5 gels an hour (over 100g of carbohydrate every 60 minutes). However, for most people, this amount is unnecessary and can increase the risk of digestive issues rather than improve performance. For the majority of people, 60-90 g per hour provides all of the performance benefits. If you are new to taking gels, 60g per hour, one gel every 30 minutes, is a simple, easy-to-follow strategy that has been shown to be very well tolerated.

The key is to start early and be consistent, rather than waiting until you feel fatigued.

5 best running gels, tested by a Health Editor and 11x Marathon Runner