Training determines much of what you are capable of on half marathon race day. But even the best training programme can be undermined by a nutrition strategy that has never been practised.

Your half marathon nutrition plan should not begin at breakfast on race morning. It should begin weeks beforehand, during your training.

You need to know what breakfast agrees with you. You need to know which gels you tolerate, how frequently you can take them, whether you prefer water or sports drink, and how your requirements change when the weather gets warmer. You also need to know where the aid stations will be and how your fuelling fits around them.

There is one principle I want you to remember throughout this guide:

Nothing new on race day.

Your long runs aren’t only opportunities to develop the endurance required to run 21.1 km. They’re also opportunities to rehearse your nutrition until race day feels familiar.

This guide takes you through that process, from the days before your half marathon through to your post-race recovery.

1. Half Marathon Nutrition Starts Before Race Day

If your first thought about race nutrition occurs when you’re packing your bag the night before your half marathon, you’ve left it too late.

Nutrition needs to become part of your training.

That doesn’t mean you need to take gels on every run. A 40-minute Level II run doesn’t require the same fuelling strategy as your longest run.

Instead, as your long runs become longer and more race-specific, use some of them to practise what you’re planning to do on race day.

That includes:

What you eat beforehand
When you eat it
How much you drink
Which gels or carbohydrate products you use
How frequently you take them
How you combine gels with water
Whether you use caffeine
How your stomach responds while running

The purpose is partly physiological, but it’s also practical.

Opening a gel while running is a skill. Drinking from a cup at an aid station without soaking yourself is a skill. Taking carbohydrate while running at your planned race intensity is different from consuming it while sitting at the kitchen table.

Train your nutrition strategy alongside your body.

2. Why Carbohydrate Matters for a Half Marathon

Carbohydrate is an important fuel for endurance exercise, particularly as intensity increases. Your body stores carbohydrate primarily as glycogen in your muscles and liver, but those stores are finite.

Current sports-nutrition guidance supports carbohydrate availability as an important component of endurance performance, with carbohydrate intake scaled to the duration and demands of the event. (PubMed)

For a half marathon, your requirements will depend partly on how long you’re going to be racing.

Someone running 21.1 km in 1:20 is dealing with a very different duration from someone who will be on the course for 2:30 or three hours.

That’s one reason I don’t want runners simply copying another athlete’s nutrition strategy.

For exercise lasting longer than around an hour, 30–60 grams of carbohydrate per hour is a useful range for half marathon runners. (ACSM)

That is the range I’ll use throughout this guide.

But the number alone isn’t the plan.

You still need to decide which products will provide that carbohydrate, how frequently you’ll consume them, how they fit with your hydration and whether you’ve trained your gut to tolerate them.

3. Train Your Gut as Well as Your Legs

Your gastrointestinal system needs to be considered when developing your half marathon nutrition strategy.

A runner may look at the carbohydrate recommendations, buy enough gels to provide 60 g per hour, and assume the problem is solved.

Then race day arrives and their stomach disagrees.

This is precisely why I want you practising your strategy during training.

Start with products you tolerate well and gradually establish what works.

If you intend to use the sports drink provided by your race organiser, find out what that product is. Buy some beforehand and practise with it.

If you intend to use gels, practise with the same brand, flavour and type you’re planning to race with.

Don’t assume one gel is the same as another.

Your long runs provide an ideal opportunity to answer questions such as:

Can I tolerate this gel after 90 minutes of running? Does caffeine upset my stomach? Do I need water immediately afterwards? Can I comfortably consume the amount of carbohydrate I’m planning?

Finding the answers six weeks before your half marathon is useful.

Finding them at 16 km on race day isn’t.

Before Your Half Marathon

4. The Day Before: Carbohydrate and Hydration

Carbohydrate loading is often portrayed as an enormous plate of pasta the night before a race.

I’d prefer you to think more broadly.

Your aim is to arrive at the start line with carbohydrate stores available for the work you’re about to ask your body to perform. That means paying attention to carbohydrate intake throughout the day before your race, rather than relying on one enormous dinner.

Formal carbohydrate-loading protocols can involve very high carbohydrate intakes over 36–48 hours, particularly for longer endurance events. However, aggressive loading may be less important for events lasting under 90 minutes, so your strategy should reflect your expected half marathon duration rather than treating every runner identically. (Gatorade Sports Science Institute)

For most recreational half marathon runners, the practical message is straightforward:

Make carbohydrate a deliberate part of your meals and snacks before the race.

At the same time, pay attention to your hydration.

There’s an interesting physiological relationship here.

When your body stores glycogen, it also stores water. Research supports the commonly used approximation that at least around 3 grams of water can be stored alongside each gram of muscle glycogen, although the relationship isn’t fixed. (PubMed)

This does not mean you should weigh your carbohydrate and then calculate that you need to drink 3 mL of water for every gram you consume.

That’s not the purpose of the information.

The point is that increasing your body’s carbohydrate stores also influences water storage. Therefore, when you’re increasing carbohydrate intake before your half marathon, maintaining good hydration is important as well.

You don’t want to arrive on race morning already playing catch-up.

5. What Should You Eat the Night Before a Half Marathon?

Keep your pre-race dinner simple.

This isn’t the time to celebrate being in a new city by choosing the most interesting item on a restaurant menu.

I prefer a meal that’s high in carbohydrate, relatively low in fat and familiar to the athlete.

Good carbohydrate bases include:

Pasta, rice or potatoes.

If you’re having pasta or rice, also consider what’s going with it.

A relatively simple vegetable- or tomato-based sauce may be preferable to a rich, cheese-heavy or high-fat sauce, particularly if that’s what you’ve successfully practised before your long runs.

The same principle applies to portion size.

Carbohydrate loading does not mean eating until you’re painfully full.

An enormous meal may leave you bloated, uncomfortable and struggling to sleep—the opposite of what we’re trying to achieve.

Think carbohydrate emphasis, not an eating competition.

And once again:

Eat foods you’ve eaten before.

Race Morning

6. Breakfast: Around 2–3 Hours Before the Start

Your race-morning breakfast has two jobs.

It should provide useful carbohydrate before the race while being familiar and comfortable enough that you’re not standing on the start line worrying about your stomach.

General sports-nutrition recommendations allow a fairly broad carbohydrate range in the hours before prolonged exercise because meal size and timing need to reflect the athlete and the time available before competition. (Gatorade Sports Science Institute)

Practically, for my athletes, I generally recommend eating breakfast around two to three hours before the start.

Keep it carbohydrate-rich, relatively low in fibre and not excessively large.

One breakfast that works well for me personally is a medium-sized bowl of muesli with yoghurt and milk, along with fluid.

That doesn’t mean you need to eat my breakfast.

You might prefer toast, fruit, cereal or another familiar carbohydrate-rich option.

The important word is familiar.

If you’ve never eaten porridge before running, race morning isn’t the morning to discover whether porridge works for you.

Likewise, if you don’t normally drink coffee, don’t suddenly decide that race morning requires three espressos because you’ve heard caffeine can improve performance.

Practise first.

7. The Final Hour Before Your Half Marathon

As the start approaches, continue following the routine you’ve rehearsed.

You shouldn’t need a huge amount of additional food if you’ve eaten an appropriate breakfast.

Complete your normal warm-up.

At the end of that warm-up, I like the option of taking a gel with some water.

That gives you a final carbohydrate top-up close to the start without requiring another substantial meal.

Again, this should be something you’ve already tested.

Your warm-up, gel, water and timing can all be rehearsed before a suitable long run or race simulation.

By race morning, you’re executing the plan—not experimenting with it.

During Your Half Marathon

8. Aim for Around 30–60 g of Carbohydrate per Hour

For the broad half marathon population, 30–60 g of carbohydrate per hour provides a useful starting range for events extending beyond an hour. (ACSM)

But here’s where runners sometimes make a mistake.

They hear:

“Take a gel every 20–30 minutes.”

And assume every gel provides the same amount of carbohydrate.

They don’t.

Imagine one gel contains 20 g of carbohydrate.

Three per hour—one every 20 minutes—provides approximately 60 g per hour.

If another product contains 30 g of carbohydrate, taking one every 30 minutes also provides approximately 60 g per hour.

The frequency is different.

The carbohydrate intake is essentially the same.

That is why I want you to read the nutrition label on your product.

Don’t build your plan around the word gel. Build it around what is actually inside that gel.

A lower-carbohydrate gel may need to be taken closer to every 20 minutes to achieve your intended intake.

A higher-carbohydrate gel may only need to be taken every 30 minutes.

And you don’t necessarily need to aim for the top of the range.

Your appropriate intake depends on your expected race duration, intensity, breakfast, other carbohydrate sources such as sports drink, and what you’ve successfully tolerated during training.

9. Take Your Gels Before the Aid Station

My preference is to take a gel before arriving at an aid station.

That way you can follow it with water.

Rather than reaching the aid station, grabbing a cup, suddenly remembering your gel and trying to juggle everything while running, you have a sequence:

Gel → aid station → water → continue running.

Find out where the aid stations are before your race.

If the event has stations every few kilometres, they can become useful landmarks in your nutrition plan.

If aid stations are sparse—or there aren’t any—then you need another strategy.

That might mean carrying a bottle, using a hydration belt or arranging another practical way to access fluid.

Don’t discover at 8 km that your entire nutrition strategy relied on an aid station that doesn’t exist.

Read the race information before race day.

10. Hydration During the Half Marathon

Hydration deserves its own plan.

Your requirements will vary considerably depending on factors including:

Temperature
Humidity
Race intensity
Race duration
Your sweat rate
Your body size
What you’ve consumed beforehand
How frequently aid stations are available

A hot half marathon in summer isn’t the same hydration problem as a cool race on an overcast morning.

If it’s hot and you’re sweating heavily, you may decide during your planning that you need to drink at every aid station.

In cooler conditions, taking fluid at every second station may be entirely appropriate for some athletes.

This is another area where your training becomes valuable.

Notice what happens on warm long runs. Notice what happens on cool ones. Learn how much you tend to drink and how you feel.

But there’s an important counterpoint:

More fluid isn’t automatically better.

Although excessive fluid intake can contribute to exercise-associated hyponatraemia, for many half marathon runners the more immediate practical consequence of drinking considerably more than they need is discomfort and needing to stop to urinate during the race.

Drinking extra fluid simply because it’s available at every aid station isn’t necessarily going to improve your performance.

So the objective isn’t:

Drink as much as possible.

It’s:

Develop and practise an appropriate hydration plan for you, the course and the likely conditions.

That preserves your coaching message without making the medical claim too absolute.

11. What About Electrolytes and Sodium?

Electrolytes can become more relevant when exercise is prolonged, conditions are hot and sweat losses are substantial.

But before adding electrolyte products to everything you consume, look at what is already in your nutrition plan.

Some gels contain sodium.

Sports drinks frequently contain electrolytes.

If you’re taking a gel containing sodium and then drinking a carbohydrate-electrolyte drink at an aid station, you’re already consuming some.

Your individual needs will vary according to your sweat characteristics and the environmental conditions.

If you’re a particularly heavy sweater, know that you lose a lot of salt when exercising, or are racing in hot conditions, this deserves greater consideration than it might for someone racing a much shorter half marathon in cool weather.

The key is awareness rather than blindly adding more.

Know what’s in your products.

12. Should You Use Caffeine?

Caffeine can enhance endurance performance, which is why you’ll see it in many sports-nutrition products.

Research supports caffeine as an ergogenic aid across several types of exercise, with low-to-moderate doses commonly demonstrating performance benefits. (SpringerLink)

That doesn’t mean everybody should suddenly become a caffeine user on race morning.

If you normally drink coffee, your normal pre-race coffee may fit comfortably into your routine.

If you never drink coffee, don’t decide that race morning is the ideal opportunity to start.

Caffeinated gels are another option and can be useful later in a race.

But caffeine can also have unwanted effects, particularly when the dose exceeds what you’re accustomed to. Depending on the individual, that can include feeling jittery, gastrointestinal discomfort or other symptoms that are hardly desirable halfway through a half marathon.

And remember that caffeine from different sources adds up.

Coffee at breakfast + caffeinated pre-race product + several caffeinated gels isn’t the same as simply taking one caffeinated gel.

Look at the label and know how much you’re consuming.

Most importantly:

Practise your caffeine strategy during training.

Different Runners Need Different Plans

13. Nutrition for Different Half Marathon Finish Times

A 1:20 runner and a 2:40 runner are both racing 21.1 km, but one will be exercising for twice as long as the other.

Their nutrition plans shouldn’t automatically be identical.

Sub-90-Minute Runner

For a faster runner, there are fewer opportunities—and less time—to consume carbohydrate during the race.

A well-practised pre-race meal, appropriate pre-start carbohydrate and a small number of well-timed in-race carbohydrate doses may be sufficient.

The athlete also needs to consider whether slowing down repeatedly at aid stations has a meaningful impact on their race.

90 Minutes to 2 Hours

As race duration increases, in-race carbohydrate becomes increasingly useful.

This is where a well-practised gel schedule can fit very naturally.

If your chosen gel provides 20–25 g carbohydrate, for example, you can plan the timing around both your target intake and the location of aid stations.

2 Hours and Beyond

For the runner who will be racing for two, two-and-a-half or three hours, nutrition becomes a much larger component of race execution.

You have considerably more time in which to consume carbohydrate, but also more time for small nutritional mistakes to accumulate.

You need a plan you know your stomach will tolerate for the entire race.

That’s why the longer your expected race duration, the more valuable those nutrition rehearsals during your long runs become.

14. Common Half Marathon Nutrition Mistakes

Many race-day nutrition problems are avoidable.

Trying Something New

The expo has a new gel flavour. Someone gives you a supplement. Your friend swears by a particular breakfast.

Save the experiment for another day.

Relying on One Huge Pasta Dinner

Your carbohydrate preparation should be considered across the day before your race, rather than expecting one enormous evening meal to do everything.

Eating Too Much

More carbohydrate doesn’t require making yourself physically uncomfortable.

Eating Too Much Fat or Fibre

Foods that are perfectly healthy in everyday life may not be ideal immediately before racing if they increase gastrointestinal discomfort.

Ignoring the Nutrition Label

One gel is not a unit of carbohydrate.

Check how many grams are actually in it.

Forgetting Carbohydrate From Drinks

If you’re drinking a carbohydrate-containing sports drink, include that when considering your total carbohydrate intake.

Waiting Until You’re Struggling Before Fuelling

Your plan should be proactive.

Don’t wait until your energy levels collapse before remembering your gels.

Overdrinking

More isn’t automatically better. Your aim is appropriate hydration, not consuming every cup available.

Ignoring the Weather

Your cool-weather hydration plan may need adjusting when race-day temperatures are considerably higher than expected.

Copying Another Runner

Their body size, pace, sweat rate, tolerance and finishing time aren’t necessarily yours.

Build your own plan.

Practise It

15. Your Half Marathon Nutrition Rehearsal

Several weeks before your race, identify a suitable long run and treat it as a nutrition rehearsal.

You don’t necessarily need to simulate the race itself.

Instead, practise the routine.

The evening beforehand, eat a similar style of dinner to the one you’re planning before your half marathon.

Hydrate appropriately.

The next morning, eat your intended race breakfast at approximately the same interval before training.

Use your planned gel products.

Use caffeine if caffeine is going to be part of your race.

Practise drinking while running.

If possible, recreate the likely race-day timing of your carbohydrate.

Then evaluate.

Did breakfast sit comfortably?

Were you hungry before you started?

Did you feel bloated?

Did the gels go down easily?

Did your stomach tolerate them late in the run?

Did you want more water after a gel?

Was your hydration strategy practical?

Did caffeine agree with you?

Would carrying four gels in the shorts you’re planning to race in actually work?

These details sound minor.

On race morning, they aren’t.

Make adjustments and practise again.

The goal isn’t simply to create a nutrition plan. It’s to create a nutrition plan you’ve demonstrated works.

Putting Everything Together

16. Your Half Marathon Race-Day Nutrition Timeline

Here’s how the complete strategy can look.

The Day Before

Emphasise familiar carbohydrate-rich foods across the day.

Maintain good hydration.

Keep dinner carbohydrate-rich, relatively low in fat and familiar. Pasta, rice and potatoes are straightforward options.

Avoid turning dinner into an enormous feast.

2–3 Hours Before the Start

Eat your practised carbohydrate-rich breakfast.

Keep it familiar, relatively low in fibre and comfortable in volume.

Consume fluid as appropriate.

During Your Warm-Up

Follow your normal routine.

Don’t introduce new foods, supplements or drinks.

At the End of the Warm-Up

Consider your practised pre-start gel.

Wash it down with some water.

During the Race

Aim broadly for 30–60 g carbohydrate per hour, depending on your race duration, product choice and practised tolerance. (PubMed)

Check how much carbohydrate is in each gel and calculate the frequency accordingly.

Where possible, take gels shortly before aid stations so you can wash them down with water.

Follow the hydration strategy you’ve developed for the course and conditions.

Adjust sensibly if race-day conditions are significantly hotter or cooler than expected.

After the Finish

Start the recovery process.

17. Nutrition Doesn’t Stop at the Finish Line

Once you’ve crossed the finish line, your immediate priority probably isn’t calculating grams of carbohydrate.

Enjoy the moment.

You’ve just finished a half marathon.

But once you’ve caught your breath and celebrated, start thinking about recovery.

You want to replace fluid, replenish carbohydrate and provide protein to support recovery.

This doesn’t require a complicated supplement protocol.

A normal meal containing carbohydrate, a useful source of protein and fluid may be entirely appropriate.

If you don’t feel like eating a substantial meal immediately, a recovery drink, milk-based drink, yoghurt, fruit or another familiar option can bridge the gap until your appetite returns.

Rapid glycogen replenishment becomes particularly important when another demanding training session or competition follows soon afterwards; otherwise, your normal post-race meals can continue the recovery process over the following hours. (PubMed)

And continue drinking according to your needs.

Again, the goal isn’t to force litres of fluid into yourself immediately.

It’s to progressively restore what you’ve lost.

18. Build Your Own Half Marathon Nutrition Plan

There isn’t one perfect half marathon nutrition plan that every runner should copy.

A sub-90-minute athlete doesn’t have the same requirements as someone racing for two-and-a-half hours.

A runner racing on a cool morning doesn’t have the same fluid requirements as that same runner competing in warm, humid conditions.

A runner who comfortably tolerates one brand of gel isn’t guaranteed to tolerate another.

And what works for your training partner doesn’t automatically work for you.

But the principles remain consistent.

Practise your nutrition during training.

Arrive at race day well fuelled and appropriately hydrated.

Use familiar carbohydrate-rich foods before the race.

Eat breakfast around two to three hours before the start.

Consider a gel and water at the end of your warm-up.

Aim broadly for 30–60 g of carbohydrate per hour during the race, adjusted for your expected race duration and what you’ve successfully practised.

Read your gel labels rather than assuming every gel contains the same amount of carbohydrate.

Plan your gels around aid stations where possible.

Develop a hydration strategy appropriate to the course, conditions and your individual requirements—without assuming more fluid is always better.

Understand where sodium and caffeine already appear in your chosen products.

And above everything else:

Nothing New on Race Day

Your half marathon nutrition strategy shouldn’t be a theory.

By the time you reach the start line, you should already know what you’re eating for breakfast.

You should know which gels you’re carrying.

You should know how frequently you’re taking them.

You should know whether you’re using caffeine.

You should know approximately where the aid stations are.

And you should have practised enough of the plan that none of it feels particularly interesting.

That’s a good thing.

Race day already contains enough variables.

Nutrition doesn’t need to be one of them.

Your job during training is to develop the plan.

Your job on race day is simply to execute it.

Want Help Building Your Half Marathon Nutrition Strategy?

Your race-day nutrition should be just as individual as your training. What works for another runner may not work for your race duration, stomach, preferred products or goals.

If you’d like help reviewing your half marathon training, fuelling strategy and race-day preparation, you can book a free 40-minute consultation with me, Coach Ray Boardman. We can talk through where you’re at now, what you’re preparing for and how you can arrive at the start line with a plan you’ve already practised and trust.

Nothing new on race day. Develop the plan in training, then execute it when it counts.