How to Fuel an Ultramarathon: Eating and Drinking When the Race Gets Long

Whether you're chasing a PB, pushing your body to its limits or simply hoping to get around in one piece, how you fuel an ultramarathon can have a huge impact on how you feel during the race — and how quickly you recover afterwards.

The problem is that there is no single perfect fuelling strategy.

Your pace, race distance, weather, terrain, sweat rate, gut tolerance and previous experience all make a difference. What works brilliantly for one runner can leave another feeling sick by halfway.

The answer isn't to eat more and more. It's to have a plan, practise it and know when to adapt it.

Start before race day

Good race-day fuelling doesn't start when the gun goes.

In the days before an ultra, focus on eating enough carbohydrate and staying well hydrated rather than trying to suddenly eat enormous amounts of one particular food.

Keep meals familiar and easy to digest as race day approaches. There's no need for a huge breakfast the night before or a last-minute attempt to "load" on everything in sight.

And don't arrive at the start already dehydrated. Keep fluids readily available in the days beforehand, particularly if you're travelling or flying.

Race morning: don't overdo it

A huge breakfast might sound sensible before a long race, but more food isn't necessarily better.

Aim for something familiar, carbohydrate-based and easy to digest. Porridge, toast with honey or jam, a bagel, banana or a small yoghurt can all work well depending on what you tolerate.

The key is practice. Your race breakfast should be something you've already tested on long training runs — not something you decide to try because another runner told you it worked for them.

Start fuelling early

One of the biggest mistakes I see is waiting until you're hungry or tired before starting to eat.

By then, you're already playing catch-up.

For a long event, start taking on carbohydrate relatively early and then keep it coming consistently. Rather than trying to consume a huge amount in one go, think little and often.

Exactly how much you need will depend on the event and the individual. Some athletes can tolerate higher carbohydrate intakes, while others will quickly develop stomach problems if they push too hard. Research and current sports nutrition practice support a wide range of carbohydrate intakes, with higher intakes possible when the gut has been specifically trained to tolerate them.

For many recreational ultra runners, somewhere around 40–60g of carbohydrate per hour can be a useful starting point, then adjusted according to pace, duration and gut tolerance.

The important bit is not the number on the packet. It's finding an intake that keeps you moving without upsetting your stomach.

Don't forget hydration

Fuelling and hydration need to be considered together, but they're not the same thing.

You don't need to force down a predetermined amount of fluid simply because you're running an ultra. Drinking excessively can be dangerous, including increasing the risk of exercise-associated hyponatraemia. Current evidence supports a more individualised approach, with thirst providing an important guide to fluid intake.

Your fluid needs will also change dramatically depending on the weather, your sweat rate, body size, pace and the availability of water.

In hot conditions, you may need considerably more fluid than you would on a cool, wet day. If you're a salty sweater or racing for many hours, sodium also needs consideration.

The answer isn't simply "drink more". Work out what you tend to lose in training and practise your hydration strategy under conditions that resemble your race.

Real food has a place too

You don't have to survive entirely on gels and sports drinks.

In fact, after several hours of sweet products, many runners reach a point where the thought of another gel makes them feel sick.

This is where real food can be incredibly useful.

Small portions of things such as:

• boiled potatoes with salt

• rice balls

• banana

• small sandwiches or wraps

• pretzels or crisps

• rice pudding

• small pieces of flapjack

can provide a welcome change in flavour and texture.

Some runners also find savoury foods such as small pieces of bacon or biltong appealing later in a race.

These don't need to replace your core fuelling strategy. Think of them as another tool in the box.

And remember that foods higher in fat, fibre or protein can be harder to digest when you're working hard. They may be perfectly fine at a walking pace late in a 24-hour race but less appealing when you're running hard early on.

Feed stations: use them strategically

Feed stations can be a lifesaver — but they're also where good fuelling plans can quickly disappear.

You arrive tired, there's loads of food in front of you and suddenly you're eating whatever looks appealing.

Instead, think ahead.

Before reaching the checkpoint, know roughly what you need for the next section. Top up your bottles, grab the food you actually need and get moving.

There may be some brilliant options available: potatoes, bananas, sandwiches, crisps, soup, cake or rice pudding.

Use them to supplement your plan rather than abandoning it completely.

And don't try something completely unfamiliar simply because it looks good at mile 40.

Race day is not the time to discover that your stomach doesn't like cheese sandwiches.

And what about the famous flat Coke?

There's a reason you'll see runners reaching for Coke towards the end of an ultra.

It's easy to consume, provides readily available carbohydrate and, if caffeinated, can provide a useful stimulant effect. It also offers a completely different taste when you've had sweet sports products for hours.

Letting it go flat can make it easier to tolerate if carbonation is causing bloating or discomfort.

It's not magic — but sometimes late in an ultra, the best fuel is the fuel you can actually face eating.

The biggest mistake? Not practising

You wouldn't turn up to an ultra having never run that distance and expect everything to go perfectly.

Your fuelling strategy deserves the same preparation.

Use your long runs to test:

• what you eat

• how much carbohydrate you tolerate

• how frequently you eat

• what you drink

• how much fluid you need

• your electrolyte strategy

• which foods you can stomach after several hours

• what happens when it's hot, cold or wet

And practise your race kit and carrying system at the same time.

Because your perfect fuelling plan on paper isn't worth much if you can't physically carry it, open it, eat it or digest it while running.

There is no perfect plan

Your fuelling strategy should give you a framework, not a set of rules you blindly follow.

You might start the race with a carefully calculated plan and finish by eating potatoes, drinking Coke and whatever else you can stomach.

That's not failure.

That's ultramarathoning.

The aim is to fuel consistently, stay hydrated, protect your gut and adapt when circumstances change.

Little and often still works — but the smartest ultra runners know when to stick to the plan and when to change it.

And that is something you can train too.