Key Nutrients for Your Marathon Training Diet

Everyone is different – foods we like and dislike, or those we’re intolerant to, just like training, something different may work for everyone. Let's clear something up straight away – proper marathon nutrition isn't just about eating your veggies and avoiding takeaways. It's about strategically fuelling your body throughout the training process and refilling your energy stores both during and after the race.

While hydration supplements and clever techniques like carb-loading before a marathon can work wonders for your performance on race day, successful marathon nutrition starts with understanding how different nutrients affect your body's performance in the long run.

Carbohydrates

Carbs are proven to be the most important nutrient for marathon athletes. They provide the majority of energy used in endurance-based exercise, preventing fatigue and fueling your skeletal muscles from a stored bank of glycogen. Eating a diet rich in complex carbohydrates — such as slow-digesting vegetables, legumes and whole grains — will enable you to train for a marathon intensely and consistently, ensuring full recovery before your next session.

Fats

Fats are a dense energy source which provide more running-fuel per gram than carbohydrates or protein. While carbs are a marathon runner's primary energy source, the body does rely on fats for energy when exercising for prolonged periods of time. Studies from the National Library of Medicine have found that low-fat diets (10%-15% of caloric intake) are less optimal for endurance when compared to higher-fat alternatives.

Factoring a balance of healthy fats into your marathon nutrition plan offers a variety of performance and health benefits – including hormone regulation, vitamin absorption and the recovery of muscles.

Proteins

Every runner knows that protein is the magic ingredient for physical performance. As part of your marathon training diet, protein helps repair and build those muscles that take such a hammering during endurance running. Your overall health gets a boost too with the right protein consumption, keeping your hormones and immune system firing on all cylinders.

On top of that, research from Sports Medicine tell us that while carbohydrates are still the star player in restoring muscle glycogen, protein makes a brilliant supporting act – especially when you're watching your carb intake.

Vitamins and minerals

Often the unsung heroes in marathon training programmes, vitamins and minerals can be the difference between hitting the wall and sailing over the finish line. Marathon runners particularly need Iron, Magnesium, Vitamin D, B Vitamins and Electrolytes – these little powerhouses help your body perform essential functions and shield it from damage and stress.

And the great thing is that you'll find these vital nutrients in loads of whole foods – think leafy greens, nuts, berries, eggs, and avocados. But supplements can be brilliant too, especially if you know you're lacking in certain areas. Studies from the National Institutes of Health discovered that skimping on either iron or magnesium can seriously hamper your energy efficiency and endurance capacity.

Fluids

Even the most perfectly crafted marathon diet won't do you much good without getting your hydration strategy spot on. Training for a marathon makes you sweat buckets to cool down, so it's essential to replace those lost minerals. Regular water intake helps deliver oxygen and nutrients around your body, stopping your muscles from cramping up and preventing dehydration as you sweat.

But remember – don't go overboard! The National Library of Medicine recommends drinking water at a rate of less than 700ml per hour to avoid diluting the sodium in your blood. Electrolyte supplements can be brilliant for maintaining your sodium levels in the days leading up to your event and on race day itself.

Always remember to have a water bottle on hand – a useful accessory for everyday use at home, work and school, not just during training periods or runs.

Marathon Nutrition Plan: What to Consume Before, During and After Your Race

A balanced, nutritious diet with plenty of hydration will set you up brilliantly for marathon training, but what should your plan look like as race day approaches?

Your food and drink choices become even more crucial as your marathon looms. We all have off-days during training, but nobody wants to fall short on the big day — especially due to something as “easy” to control as nutrition and hydration.

So whether you're wondering what to eat before a half marathon, or how to help your body bounce back after conquering the full 26.2 miles, here's everything you need to know about tailoring your nutrition around the big day.

What to eat before a marathon

With race day around the corner, timing your meals becomes even more important. Eating too much before an endurance race can leave you feeling bloated and sluggish, while eating too little might see your energy stores emptying out far too quickly. The key to success? Striking that perfect balance in the days leading up to your event.

Two days before:

Carbohydrates will be your primary source of energy on the day, so start upping your intake of them two days prior to your race. Swap out foods from your marathon training diet for options that are richer in carbohydrates, making sure to avoid overeating to the point of bloating or discomfort. Prioritise high-carb foods that are easily digestible, such as:

• Pasta
• Rice
• Bread
• Oats
• Bananas

When carb-loading before a marathon, The National Library of Medicine suggests eating 10-12g of carbohydrates per kilogram of body weight in the 48 hours leading up to your event.

The night before:

Before you tuck yourself in for that crucial pre-marathon sleep, focus on a light dinner rich in those slow-burning carbohydrates. With less than 24 hours to go, you'll want to be extra careful not to eat too much or upset your stomach.

Stick to familiar, carb-rich foods like rice, pasta, potatoes, or quinoa. And don’t shy away from adding a bit of protein – think chicken, tofu, or fish – to help slow digestion. Wash it all down with plenty of water and some electrolytes to keep you properly fuelled.

The morning of:

Breakfast is always important, but it's absolutely crucial on marathon morning. Focus on quick-digesting carbohydrates like a plain bagel or porridge cooked in water, with a small dollop of peanut or almond butter for protein. And for hydration, drink 500-700ml of water or a sports drink 2-3 hours before the race.

It's best to minimise or completely avoid fibre, as it can play havoc with your digestion if you have it right before a marathon. Race day is definitely not the time to try something new, so stick with familiar foods that have treated you well during training.

What to eat during a marathon

While your main focus will be giving it your all, your marathon nutrition plan doesn't end when the starting gun fires. Your body will burn through thousands of calories before reaching the finish line, so you'll need to keep those energy stores topped up consistently.

Energy gels and chews:

When you're pushing hard for a long time, you'll need to replenish your glycogen stores with 30-60 grams of fast-acting carbs every hour. Energy gels, chews, and sports drinks are a favourite among marathon runners because they deliver just the right amount of nutrition in a way that’s easy to consume. These are often given away at drink and gel stations along marathon routes, but it's always smarter to bring your own rather than experiment with anything new mid-race.

Real food:

There are plenty of whole food options that deliver the same energy boost as running gels during a marathon. Bananas, dates and other fruits that are easy to digest will top up your glycogen levels with carbohydrates and simple sugars. And if you want to avoid potential mess, bringing small portions of dried fruit also work wonders.

Just remember you'll need to store your mid-race snacks somewhere while running. A running backpack or belt offers practical, lightweight storage, while cutting larger foods into small chunks means easy refuelling on the move.

Fluids:

Even though you should be well-hydrated in the weeks and days before your marathon, you'll still need to drink regularly throughout the race. Take small sips of water or a sports drink in the hour before the start, but don't overdo it – and remember to keep toilet breaks in mind!

Make sure you know where hydration stations will be and take full advantage of them, grabbing water and electrolyte drinks as needed. Small, frequent sips help your body absorb fluids more efficiently, and you can adjust based on the temperature and how much you're sweating. It's really useful to practice your mid-race hydration strategy during your longer training runs.

What to eat after a marathon

Congratulations, you've done it! You’ve crossed the finish line, raised your arms triumphantly and claimed your well-earned medal. While it's definitely time to celebrate, you're not quite done yet. What you eat and drink after racing determines how well your body recovers, from repairing tissue and restoring glycogen to preventing muscle breakdown.

Immediately after:

You might not be thinking about your next training session just yet, but consuming carbohydrates and protein within the hour after finishing is vital for getting your body back to peak condition. Carbs help replenish the muscle glycogen you've burned through, while protein kicks off the process of repairing and rebuilding all the muscle tissue that have been damaged.

Aim for a 3:1 ratio of carbs to protein in your post-race snack – think a fruit smoothie with some protein powder, or a few rice cakes with a thin layer of nut butter. The sooner those carbs and proteins can start working their magic, the better – so try to avoid nutrients that slow digestion like fat or fibre.

Later in the day:

Exercise often gets in the way of your appetite, so it's perfectly normal not to feel particularly hungry in the hours after your marathon. A quick post-race carb and protein snack should help kick your digestive system back into gear. But remember – it's important to have a carb-heavy meal a few hours after finishing, even if you're not feeling particularly hungy.

To continue building your glycogen back up and repairing muscle tissue, your post-marathon meal should be rich in both carbohydrates and protein. If your appetite is still on the quiet side, try breaking your nutrient intake into small carb and protein-rich snacks to start the recovery process in a way that feels comfortable.

Water and electrolytes:

Even if you've been on top of your hydration game throughout your race, your body will likely need fluids when you cross the finish line. Try to drink 400-700ml of fluids in the first hour after your marathon – both water and electrolytes if you can – and repeat this over the next three hours. Also, pro tip; washing down your post-race snack with fluids will help with digestion and give your body some much-needed rehydration.

And if you're experiencing severe dehydration symptoms like extreme thirst, dark urines or dizziness, don't take any chances. See a doctor right away. Research from the National Library of Medicine shows that most endurance athletes don't quite meet their hydration needs during competitions, usually due to a combination of intensity, duration and temperature. So make sure you stay on top of things.

Foods and Drinks to Avoid or Limit When Training for a Marathon

Knowing what foods work for you on marathon day great – but understanding what to steer clear of can be just as important. Experimenting with your food choices should start long before race day, because if you try something new on the day and it doesn’t work, it can get in the way of you performing at your best.

So, whether you're just putting together your marathon nutrition plan, or looking for red-flag foods before an upcoming race – here's our list of what to avoid:

● Fatty Foods: Anything that’s excessively high in fat will be naturally slower to digest and can leave you feeling bloated or sluggish. Try to avoid heavy sauces, fried foods, high-fat desserts and anything cooked in lots of oil or butter.

● Spicy Foods: While delicious, heavily spiced foods can lead to heartburn and digestive issues, so it’s best to avoid overeating them when preparing for any long-distance event.

● Dairy: While this is an obvious no-no for lactose-intolerant runners, dairy can create digestive problems for anyone taking part in intense, prolonged exercise so try avoiding it.

● Alcohol: Drinking alcohol means trouble in virtually any sport, but it's particularly true for marathon running thanks to its dehydrating effects.

● Sugar: While sugar can be helpful when used strategically in your marathon diet plan, having it regularly causes sudden spikes and drops in blood pressure, which will lead to rollercoaster energy levels.

● Excessive Caffeine: Sure, it’s a natural stimulant that can boost performance when used wisely – but unrestricted caffeine intake can also lead to dehydration (and unwanted bowel stimulation).

Power Past the Finish Line With the Perfect Marathon Nutrition Plan

How we fuel our bodies can make or break our performance on race day, so having a solid marathon nutrition plan is absolutely vital. Whether you're hitting the pavement this summer, preparing for a shorter event, or simply curious about what it takes to fuel 26.2 miles of running – the advice above is all you need to start eating and drinking for endurance success.

Remember that everyone is different and if you need personalised help or advice, consult a doctor or other professional who can help. Don’t compare your diet to those around you, as what works for them might not work for you!

Ready to hit your new personal best? Explore our marathon essentials for a hand-picked selection of running shoes, clothes and accessories that are designed to go the distance.