For many endurance sessions lasting around 1 to 2.5 hours, 30 to 60g of carbohydrate per hour is a useful starting range. For longer events, experienced athletes may work towards higher intakes, often up to around 90g per hour, and a select few can handle even more, but only if they have practised in training.

It's a hot topic right now. The right number depends on duration, intensity, gut tolerance, heat and how easy it is to eat or drink while moving.

The Fuel Finder turns these broad ranges into a practical basket of drink mix, gels, chews, bars and hydration products.

Carbohydrate helps support working muscles and the brain during longer or harder endurance efforts. When carbohydrate availability drops, athletes may struggle to hold pace, make good decisions, climb well or finish strongly.

This is why a fuelling plan matters. The aim is not to eat as much as possible, even although you've heard the joke about it being an eating competition as well as a running one! But he aim is to take in enough carbohydrate to support the body and see the session out, without overwhelming your stomach.

Yes, some easy or short endurance sessions can be done with little or no carbohydrate intake, especially if the aim is aerobic conditioning rather than pace. Some athletes also use fasted or low-glycogen sessions to practise using fat more efficiently and engage the bodies natural mitochondria (the bodies energy making machines).

But this is not the same as saying carbs don't matter.

Higher-intensity sessions, long events, races and hard training blocks typically benefit from carbohydrate availability. Low-fuel training can increase stress on the body, reduce session quality and make recovery harder if it is used too often.

A balanced approach is usually best: use lower-fuel sessions deliberately, but fuel the sessions where performance, intensity, race practice or recovery matter.

The Fuel Finder is designed for the sessions where fuelling has a job to do.

We often get told that someone is beginning to run and what should they take. The answer to this question is a no. Short, easy or low-intensity sessions do not need extra carbohydrate during the session itself.

Longer, harder or race-specific sessions are different.

As a simple guide, the longer and harder the effort, the more useful a structured fuelling plan becomes.

The Fuel Finder helps separate short training sessions from longer endurance work, so you do not overfuel when you do not need to.

Everyone needs electrolytes. They help with normal fluid balance, nerve signalling and muscle function, and most people get them every day through food and drink.

For endurance athletes, the issue is not that electrolytes are unusual or special. The issue is sweat. During long, hot, humid or high-sweat sessions, you lose fluid and sodium through sweat. If those losses become significant, hydration becomes more than just drinking water.

Sodium is usually the main electrolyte to think about during endurance exercise. A short cool run may not need dedicated electrolyte support, but a hot marathon, long ride, ultra or salty-sweat profile may need a more deliberate sodium and fluid strategy.

You may need more sodium if you sweat heavily, finish sessions with salt marks on your kit, train in hot conditions, cramp, or lose a lot of fluid during long sessions.

This does not mean every athlete should take maximum sodium. It means hydration should be matched to the session and conditions.

RSG's Fuel Finder uses these signals to decide whether hydration support should be part of the basket.

Water is, of course, essential, and dehydration can quickly make endurance efforts feel harder. But during longer, hotter or sweat-heavy sessions, hydration is not only about replacing fluid.

When you sweat, you lose water and electrolytes, especially sodium. Sodium helps the body hold and use fluid properly, so simply drinking more water is not always the best solution.

The practical aim is to replace enough fluid while also considering sodium, carbohydrate and gut comfort.

Our Fuel Finder helps decide when water is enough, and when electrolyte support has a job to do.

Now we get a bit more technical - and you thought you only had to run or cycle!

We're kidding, gut training means practising your race-day fuelling plan before race day.

The aim being to get your body get used to taking on carbohydrate and fluid while running, riding or racing.

This matters most when you are aiming for higher carbohydrate intakes.

A plan that looks sensible on paper still needs to work in your stomach, at your pace, in your conditions.

Running, cycling or swimming for hours an end wreaks havoc on your bodies energy systems. Ready Sweat Go understands that we all train hard, often over many months (years?) and spend lots of time and money in getting to our chosen events.

Race day is not the time to discover that a gel, drink mix, chew, bar or caffeine dose does not suit you. Practising in training helps you refine timing, flavour, texture, caffeine and hydration.

Our Fuel Finder gives you a strong starting basket. Your long runs, rides and race-specific sessions help you make it your plan.

This is a more common question than people realise.

If fuel upsets your stomach in training, the answer is not always to stop fuelling. It may mean the format, timing, amount, concentration or product type needs adjusting.

Some athletes struggle with gels but do better with drink mix. Others prefer chews, bars or a mix of formats. Caffeine, strong flavours, highly concentrated drinks or taking fuel too quickly can also get in the way.

It can be quite mind boggling and it can take practise.

We've built the Fuel Finder around practical preferences, not just grams of carbohydrate.

If you already know a format does not suit you, you can choose alternatives that make it easier to stay properly fuelled. And remember when it comes to fuelling practice really does make perfect.

The best endurance fuel is not always the product with the highest carbohydrate number. It's the fuel you can carry, tolerate, absorb and use consistently at the pace and intensity of your event.

For many runners and cyclists, drink mix becomes the foundation because it delivers carbohydrate, fluid (and often electrolytes) together. It is especially useful on the bike, in long runs where you carry soft flasks, and in events where steady fuelling matters more than single big hits of energy.

Gels are useful because they are compact, fast and easy to dose on the move. They work well for running, cycling, triathlon and late-race top-ups when you want carbohydrate without chewing.

Chews sit somewhere between gels and bars. They give measured carbohydrate but with a different texture, which can help when you are tired of gels or sweet drinks.

Bars can be useful in longer, steadier efforts, especially cycling, hiking, ultra-distance events and lower-intensity sections where chewing feels manageable. Runners often find solids harder at higher intensity because of stomach movement and reduced blood flow to the gut.

The Fuel Finder helps match the format to the session, not just the headline carbohydrate target.

As much as it may seem tempting, for a first ultra, the aim is not to eat as much as possible.
The aim is to keep energy steady, protect your stomach and keep moving well for longer than your normal training runs.

Ultra runners often say the sport is “an eating contest with running involved.” There is some truth in that, but it can be misleading. More fuel is not automatically better if it makes you feel sick, bloated or unable to run.

A sensible first-ultra basket usually includes a mix of formats: drink mix for steady carbohydrate and fluid, gels or chews for easier dosing, electrolytes for longer or hotter conditions, and some more solid options if the pace is low enough to tolerate them.

As the event gets longer, flavour fatigue becomes real. What tastes fine at mile 5 may feel unbearable at mile 28. Having a mix of textures and flavours can make it easier to keep fuelling when appetite drops.

RSG's Fuel Finder gives you a starting basket you can test in long runs before race day.

Not always, but often, yes. Runners and cyclists can use the same types of products, but they do not always tolerate them in the same way.

Cyclists usually have more carrying space, less stomach bounce and more chances to drink from bottles. That makes drink mix, bars, chews and gels easier to combine.

Runners usually need lighter, more compact fuel. Gels, chews, soft flasks and drink mix often work better than heavier solid food, especially at marathon pace, trail race pace or higher intensity.

For triathlon, the bike leg is often where the main fuelling work happens. The run needs to be simpler, easier on the gut and already practised.

The Fuel Finder asks about the type of session because format matters. A good basket for a sportive may not be the same as a good basket for a marathon, even if the carbohydrate target looks similar.

Fuel often feels harder to tolerate later in a race because the body is under more stress. As intensity, heat, fatigue and dehydration rise, digestion can become impaired and less comfortable.

During harder endurance efforts, blood flow is prioritised toward working muscles and cooling the body. That can make the stomach less forgiving, especially if you take on too much fuel at once, use very concentrated drinks, ignore fluid intake or rely on products you have not practised with.

This is why experienced athletes do not just ask, “How many grams of carbohydrate can I take?” They ask, “What can I keep taking when I am tired, hot and still moving?”

The practical answer is usually a steady plan, smaller regular doses, enough fluid, sensible sodium and formats you have already tested in training.