How Much Carbohydrate Do You Actually Need During a Run?

Do you need carbohydrate during your run?

For plenty of runs, the answer is no.

If you're heading out for 30 or 40 minutes at an easy pace, taking a gel is unlikely to make any meaningful difference.

But as the run gets longer, harder or more important, carbohydrate becomes more useful.

The problem is that once you start looking for advice, you quickly find numbers everywhere:

30 grams per hour.

60 grams.

90 grams.

Sometimes 120 grams or more.

That can make something fairly simple feel unnecessarily complicated.

Rather than starting with a number, start with the run:

How long am I running? → How hard? → What did I eat beforehand? → What am I preparing for? → What can I tolerate?

Those five questions will usually get you much closer to the right answer.

A simple starting point

Established sports-nutrition guidance gives us a useful duration-based framework:

• Less than 45 minutes: Normally no carbohydrate needed during the run.
• Around 45–60 minutes: Most ordinary recreational runs still won't need it. Small amounts of carbohydrate or even a carbohydrate mouth rinse may have a role during genuinely hard performance-focused exercise.
• 60–90 minutes: It depends increasingly on intensity, what you've eaten beforehand and the purpose of the session.
• Around 90 minutes–2.5 hours: 30–60 g/hour is a well-established range when fuelling is useful.
• Beyond roughly 2.5–3 hours: A planned strategy becomes increasingly important. Some runners may work towards around 90 g/hour, particularly using glucose + fructose carbohydrate sources.
• Above 90 g/hour: This is specialist, event-specific territory rather than a standard target for recreational runners.

These aren't rigid cut-offs.

A relaxed 61-minute run doesn't suddenly need a gel because you've crossed the one-hour mark.

And a hard race lasting 75 minutes is not the same nutritional problem as a comfortable 75-minute Sunday run after breakfast.

Duration is the starting point, not the whole decision.

Why does carbohydrate become more useful as runs get longer?

Your body stores carbohydrate mainly as glycogen in your muscles and liver, alongside glucose circulating in your blood.

Those stores are limited.

During shorter runs, however, most adequately fed runners already have plenty of carbohydrate available. You don't need to continually replace everything you're using from the moment you start running.

As exercise becomes longer, particularly when the intensity is reasonably high, carbohydrate availability becomes more important.

A 2026 umbrella review by Tarrit and colleagues examined 15 reviews covering 262 randomised controlled trials. The clearest practical support for consuming carbohydrate during exercise was around prolonged endurance work, particularly exercise lasting roughly 1–4 hours.

There is an important limitation here: 11 of the 15 reviews were rated low or critically low quality.

So the evidence doesn't justify pretending there is one precise intake that every runner must follow.

It does support the broader principle that carbohydrate tends to become more useful as endurance exercise becomes longer and more demanding.

Do you need a gel for a normal one-hour run?

Usually, no.

Imagine a normal BE Fit Coach-style group session.

You've eaten normally during the day. The session lasts around an hour. Some parts may be challenging, but you aren't racing flat-out continuously.

There is little reason to automatically add a gel.

Research does suggest that relatively small carbohydrate amounts, and sometimes simply rinsing carbohydrate around the mouth, can affect performance during sustained hard exercise lasting around 45–75 minutes.

That can matter in a hard 10K race or performance-focused session.

It doesn't mean:

“If I'm exercising for an hour, I need a gel.”

The type of hour matters.

What about 60–90 minutes?

This is probably the greyest area.

An adequately fed runner doing an easy 70-minute run may still have little reason to fuel during it.

Change the situation, though, and the answer may change.

For example:

• You're running hard for 90 minutes.
• You're training early after eating very little.
• The session is an important long run during marathon preparation.
• You're preparing for a race and want to practise your fuelling.

Carbohydrate becomes more relevant.

That's why I wouldn't automatically prescribe 30–60 g/hour to everyone the moment their watch ticks past 60 minutes.

Ask what the session is actually trying to achieve.

Around 90 minutes–2.5 hours: 30–60 g/hour is a useful range

Once we're into prolonged endurance running, the case for planned carbohydrate becomes much stronger.

For roughly 90 minutes to 2.5 hours, 30–60 g/hour remains a sensible, well-supported range when fuelling is useful.

You don't necessarily have to start at 60.

A runner who currently takes very little carbohydrate may be perfectly well served beginning towards the lower end and seeing how they respond.

And it doesn't have to come from gels.

Carbohydrate can come from:

• Gels.
• Sports drinks.
• Chews.
• Suitable foods.

The gel is simply a convenient delivery method.

Half marathon fuelling: finishing time matters

This is where advice based only on distance becomes misleading.

One runner might finish a half marathon in 85 minutes.

Another might take 2 hours 30 minutes.

They are doing the same distance, but they aren't facing the same fuelling problem.

A faster runner who has eaten appropriately beforehand may only need a relatively modest amount during the race.

Someone expecting to spend more than two hours on course has a much stronger reason to use a planned carbohydrate strategy, potentially somewhere within that 30–60 g/hour range.

So instead of asking:

“How many gels do I need for a half marathon?”

I'd ask:

“How long will I probably be running, and what intake have I already shown I can tolerate?”

Marathon fuelling needs more planning

For most recreational marathon runners, the duration is long enough that carbohydrate availability becomes an important part of race performance.

It isn't the only reason runners slow down.

Pacing, muscular fatigue, heat, hydration and how well the runner maintains their physical capacities as fatigue builds can all contribute.

I'll look at that wider issue separately in Why Being Fit Enough to Run the Pace Isn't Enough.

But for the marathon itself, simply waiting until you feel empty before taking carbohydrate is unlikely to be a good strategy.

For events lasting beyond roughly 2.5–3 hours, some runners may benefit from building towards higher carbohydrate intakes, potentially up to around 90 g/hour.

This is also where the type of carbohydrate starts to matter more.

Why glucose + fructose?

Glucose and fructose use different transport pathways in the intestine.

Combining them can allow more ingested carbohydrate to be absorbed and used than relying heavily on glucose alone.

A 2026 study by Barney and colleagues again demonstrated higher exogenous carbohydrate oxidation when athletes consumed glucose + fructose compared with glucose alone.

But there is an important distinction:

Using more of the carbohydrate you've eaten is not automatically the same thing as performing better.

Higher oxidation is an interesting physiological finding.

A performance advantage still needs to be demonstrated rather than assumed.

That becomes particularly important when we start talking about very high carbohydrate intakes.

Do runners now need 90–120 g/hour?

No.

90 g/hour is not a minimum.

And 120 g/hour has not suddenly become the evidence-based standard for ordinary runners.

Some elite endurance athletes are using 100–120 g/hour or more, and research shows that the body can sometimes absorb and oxidise impressive amounts of carbohydrate when the right mixtures are used.

But the obvious question is not:

“Can the body use it?”

It's:

“Does taking more make the athlete perform better?”

A 2026 Sports Medicine review by Plews and colleagues examined these ultra-high carbohydrate strategies.

Their conclusion was much more cautious than some of the claims you may see online.

Although carbohydrate oxidation can continue increasing above traditional intakes, controlled evidence has not shown a consistent performance dose-response beyond approximately 90 g/hour.

For recreational runners, that means 100 or 120 g/hour should be treated as specialist experimentation, not a target everybody should gradually work towards.

More isn't automatically better.

Your gut gets a vote

This is one of the most important parts of any fuelling plan.

A theoretically perfect carbohydrate intake is useless if it leaves you feeling sick, bloated or urgently looking for a toilet.

Gastrointestinal tolerance varies considerably between runners.

There is evidence that repeated practice with carbohydrate during training can improve tolerance.

A 2023 systematic review of gut-training strategies found some evidence for improved gastrointestinal comfort and reduced signs of carbohydrate malabsorption, although the research base was relatively small and there wasn't strong evidence that gut training itself directly improves performance.

The practical message is simpler than the phrase gut training makes it sound:

Practise what you plan to eat and drink on race day.

Find out:

• Which products work for you.
• How much you can tolerate.
• How often you prefer taking it.
• How much fluid you need alongside it.
• Whether the strategy still works at race-like intensity.

The best target isn't the biggest number you can force down.

It's the amount that supports your event and that you can reliably tolerate.

Does running in the heat mean you need more carbohydrate?

Not automatically.

Heat can change the whole experience of a run. Pace may fall, fluid requirements may increase and gastrointestinal tolerance can become more difficult.

But there isn't good evidence for simply increasing carbohydrate intake because the temperature has risen.

A 2026 systematic review by Salame and colleagues looked at carbohydrate supplementation during endurance exercise in the heat.

Five of nine studies found a performance benefit and four did not. The research did not support a separate blanket carbohydrate target for hot conditions.

So rather than:

“It's hotter, therefore I need more carbohydrate.”

Think:

“Does my existing strategy still work under these conditions?”

Hydration, pacing and tolerance may need more attention.

The carbohydrate target doesn't automatically have to go up.

Training fuelling and race fuelling don't always need to match

If you're planning to race at 60 g/hour, does every long run need to contain exactly 60 g/hour?

No.

Training sessions have different purposes.

A relaxed 90-minute run after breakfast does not necessarily need the same fuelling strategy as the first 90 minutes of your marathon.

But you also shouldn't invent your race-day plan on race morning.

Some appropriate training sessions should rehearse what you intend to do during the event.

That includes practising:

• The amount.
• The products.
• The timing.
• The fluid alongside them.
• Carrying and opening everything while running.
• Taking carbohydrate at something close to race intensity.

So training fuelling doesn't always need to match race fuelling.

But race fuelling does need to be practised in training.

What does that look like for a normal runner?

30–45 minute easy run

You've eaten normally and you're running comfortably.

Likely approach: No carbohydrate during the run.

45–60 minute group run

A normal evening group session after eating during the day.

Likely approach: No gel needed.

If you're doing genuinely hard performance-focused work, carbohydrate may have some relevance, but don't turn that into a rule for every one-hour session.

60–90 minute run

This depends on what you're doing.

An easy, adequately fed 70-minute run might need nothing.

A hard 90-minute workout, low-fuel early-morning session or race-specific run may justify carbohydrate.

Likely approach: Context-dependent.

90 minutes–2.5 hours

Carbohydrate becomes increasingly useful, especially when session quality or race preparation matters.

Likely approach: Around 30–60 g/hour is a sensible range when fuelling is needed.

Half marathon

Think about expected finishing time rather than the distance alone.

Likely approach: A faster runner may need relatively little during the race; someone running for two hours or more has a stronger case for a structured intake.

Marathon

A planned strategy matters much more.

Likely approach: Build an intake that suits your likely race duration and that you've practised. Some runners may work towards higher intakes, potentially up to around 90 g/hour, often using glucose + fructose products.

More than 90 g/hour

Likely approach: Only for a clear event-specific reason, with extensive practice and good tolerance.

It is not the new normal.

Coach's Decision

Don't start with the number on the gel packet. Start with the run.

Short and easy may need nothing.

As duration and demand rise, carbohydrate becomes more useful. Once training or racing becomes prolonged, use a planned strategy rather than waiting until you feel empty.

For roughly 1–2.5 hours, 30–60 g/hour is a well-supported range when fuelling is needed.

For longer events, some runners may benefit from working towards higher intakes, potentially up to around 90 g/hour, usually using glucose + fructose products if tolerated.

Go beyond that only for a clear event-specific reason and after practising it.

The best target isn't the biggest number you can force down. It's the amount that supports the event and that you can reliably tolerate.

If you have a longer race coming up, don't leave your fuelling plan until race morning.

Use appropriate long runs and race-specific sessions to work out how much carbohydrate you need, which products you tolerate and how you're actually going to take them.

A strategy you know works is much more useful than chasing the biggest grams-per-hour number you've seen online.

Research informing this article

• Tarrit B et al. (2026). Interest of carbohydrate consumption during endurance exercise: a systematic review of systematic and meta-analyses of RCTs. Journal of Sports Medicine and Physical Fitness.
• Barney DE Jr et al. (2026). Exogenous Carbohydrate Oxidation Is Higher When Consuming Glucose + Fructose Compared with Glucose Alone during Endurance Exercise Regardless of Energy Status. The Journal of Nutrition.
• Plews DJ et al. (2026). Fuelled or Fooled? Examining the Evidence and Mechanisms Behind Ultra-High Carbohydrate Intake in Endurance Athletes. Sports Medicine.
• Salame A et al. (2026). Carbohydrate supplementation for endurance exercise in the heat: a systematic review with practical recommendations. Journal of the International Society of Sports Nutrition.
• Martinez IG et al. (2023). The Effect of Gut-Training and Feeding-Challenge on Markers of Gastrointestinal Status in Response to Endurance Exercise: A Systematic Literature Review. Sports Medicine.
• Thomas DT, Erdman KA & Burke LM (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance.