Running Gels, Supplements And Carb Loading: What Every Distance Runner Needs To Know

If you spend any time on social media, you'd be forgiven for thinking you need a suitcase full of gels, supplements and expensive nutrition products just to complete a half marathon. Every week there's a new influencer promoting the latest miracle product, while brands compete to convince runners that they're missing out if they don't buy the newest formula.

On our Bitten By The Running Bug podcast series we recently sat down with sports nutrition researcher and endurance specialist Matt Carpenter, a lecturer in Sports Science at the University of Northampton who is completing a PhD in performance nutrition, to separate the science from the marketing. His advice was refreshingly straightforward: focus on training first, nutrition second and don't overcomplicate things.

HAVE A LISTEN TO THE PODCAST HERE

Gels Are Convenient, Not Essential

One of the biggest misconceptions among new runners is that gels are some kind of performance-enhancing product. They're not. A gel is simply a convenient way of consuming carbohydrates while you're running. There's nothing magical about them. They don't contain secret ingredients that suddenly make you run faster or further. They simply replace energy that your body is using during exercise.

For someone training for a 10K, you almost certainly don't need gels at all. Your body already stores enough carbohydrate to comfortably cover the distance, assuming you've eaten normally beforehand. Buying expensive gels for a race that lasts under an hour is, for most runners, completely unnecessary.

How Many Gels Do You Need For A Half Marathon?

Half marathons are where runners often start questioning their nutrition. According to Matt, most runners only need one or two carbohydrate intakes during the race. That could be gels, but it doesn't have to be. Sports drinks, jelly sweets, Turkish Delight or homemade carbohydrate drinks all achieve the same basic goal. They're simply providing carbohydrate.

The important point is that whatever you choose, you should practise with it during training. Race day is never the time to experiment with a new flavour, brand or nutrition strategy. If your stomach doesn't agree with it, you'll discover that far too late.

Marathon Nutrition Is More Important, But More Isn't Better

The marathon is where carbohydrate intake becomes much more relevant.

Most runners will be exercising for well over three hours, meaning their body's stored carbohydrate is likely to become depleted. That's why some form of carbohydrate replacement during the race makes sense. However, this doesn't mean you should consume as much as possible.

One of the biggest mistakes runners make is assuming that if a couple of gels are good, six or seven must be even better. Unfortunately, that's often the quickest route to stomach problems and an uncomfortable visit to the nearest portable toilet. Instead, use your long training runs to work out what works for you. Every runner is different. Some people tolerate higher carbohydrate intakes extremely well, while others perform much better on smaller amounts.

The goal isn't to consume the most carbohydrate. It's to find the amount that allows you to run comfortably without upsetting your stomach.

Don't Forget About Hydration

With so much attention on gels, hydration is often overlooked. Many runners tear open a gel, swallow it whole and carry on without taking any water. That can increase the chance of digestive problems, especially during warmer races. Sports drinks can often be an excellent alternative because they provide both fluid and carbohydrate at the same time.

As spring marathons increasingly take place in warmer conditions, maintaining hydration may be just as important as replacing carbohydrate.

Can You Run A Marathon Without Gels?

Surprisingly, yes. Many experienced runners have completed marathons without taking a single gel, while some ultra runners complete astonishing distances using very little carbohydrate at all. That doesn't mean it's the best strategy for everyone, but it does demonstrate just how capable the human body is when it's well trained.

Your ability to burn fat improves dramatically through consistent endurance training. The fitter you become, the less reliant you are on stored carbohydrate during easier running.

Nutrition should support your training, not replace it.

Which Supplements Actually Work?

The supplement industry is worth billions, but surprisingly few products have strong scientific evidence behind them. According to Matt, only a handful consistently demonstrate performance benefits for endurance athletes.

Caffeine

Caffeine remains one of the best researched performance supplements available. It can reduce the feeling of effort and help runners maintain pace during longer events. The key is understanding your own tolerance. Some runners thrive after a coffee, while others become anxious or experience stomach problems. If you normally drink coffee before training, there's little reason to change your routine before race day.

Beetroot Juice

Beetroot juice also has solid scientific evidence behind it. It works by increasing nitric oxide availability, improving blood flow and helping oxygen reach working muscles more efficiently. The catch is that the benefits are relatively small. It isn't a miracle drink that suddenly transforms your marathon time, but it may provide a slight performance advantage if you've already tested it in training.

Creatine

Creatine is hugely popular among gym users, but what about runners? While the evidence isn't as strong for endurance performance, creatine may help support recovery and improve strength training sessions, both of which can benefit marathon runners over time. It's also inexpensive and well researched for safety, making it one of the lower-risk supplements for runners who regularly include strength training alongside their running.

Electrolytes?

Electrolytes are another area surrounded by confusion and for most runners, they're unnecessary during normal training. However, if you're completing very long sessions, training in hot weather or undertaking particularly heavy marathon training weeks, replacing sodium through electrolyte drinks may become more important. Like everything else, context matters.

Is Carb Loading Worth It?

Few topics generate more debate than carb loading. Many runners interpret it as permission to eat enormous bowls of pasta the night before a marathon, but that's rarely the best approach. In reality, your taper naturally helps increase carbohydrate stores because you're training less while often maintaining similar food intake. Instead of dramatically increasing the amount you eat, think about eating smarter.

Replacing higher-fibre foods with lower-fibre alternatives during the final couple of days may reduce digestive issues on race morning. Swapping brown rice for white rice or wholemeal bread for white bread can achieve this without forcing yourself to overeat. Most importantly, don't suddenly introduce foods you never normally eat. If your pre-race nutrition worked before your longest training run, it's likely to work again before race day.

Practise Everything During Training

Perhaps the biggest lesson from our conversation wasn't about supplements at all. Practise your breakfast, your hydration, your carbohydrate intake, your clothing, your shoes and even your timing. By the time you reach the start line, nothing should be new. Every long run should be treated as a rehearsal for race day. That's how confidence is built.

The Bottom Line On Gels, Supplements And Carb Loading

Running nutrition has become far more complicated than it needs to be. Gels have their place, but they're simply convenient carbohydrates. Supplements can offer small advantages, but they won't compensate for poor training. Carb loading can help, but only if it's sensible and practised beforehand. The runners who consistently perform well aren't usually the ones buying every new product on the market. They're the ones who train consistently, fuel appropriately and avoid changing anything on race day. When it comes to distance running nutrition, keeping things simple is often the smartest strategy.

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HAVE A LISTEN TO THE PODCAST HERE