What to eat if... you're running a marathon

For distance runners, there's much more to planning a training diet than simply loading up on carbs. Here's the 101 on marathon nutrition

By National Geographic Traveller Food
Published 11 Apr 2018, 16:00 BST, Updated 14 Jul 2021, 12:18 BST
Albatros Travel; Great Wall of China marathon
Albatros Travel; Great Wall of China marathon

Run. Eat. Sleep. Repeat. Nothing quite sums up the discipline, drive and monotony it takes to train for a marathon than these four words. Yet, despite its crucial role, marathon nutrition is often taken for granted and can quickly derail all that hard graft — typically 12–20 weeks' training, building up a weekly mileage of at least 50 miles. In fact, as endurance runner Susie Chan believes, there's a common misconception that marathoners can eat whatever they want.

"While running is good for you, 5km isn't going to burn off a slice of cake," says Chan. "When it comes to training, you can certainly afford to indulge a bit more, but a good balanced diet will help you fuel and recover."

Chan, whose experience includes the Marathon des Sables — a six-day, 156-mile ultra-marathon in the sweltering Sahara Desert — admits to not being that strict. It's simply about listening to her body and eating plenty of vegetables, fish and carbs.

Carbs are the cornerstone of any successful marathon. But that doesn't mean gorging on pizzas and chips. Instead, think slow energy-releasing carbs, such as rolled oats, rye bread, basmati rice, wholewheat pasta and sweet potatoes, which also contain anti-inflammatory agents. Bananas are arguably the best pre- and post-run food as they're almost all carbs, zero fat and high in potassium, which is lost when sweating.

Carbs are so important for endurance that marathoners are advised it should make up 50-60% of their daily calories, with the remainder split between protein and fats. Protein-wise, one egg meets 10% of your daily protein needs, plus 30% of your recommended intake for vitamin K — vital for healthy bones.

In recent years, low-carb, high-fat running has been on the rise. The idea being that the more fat you eat, the better adapted you become to getting energy from fat, which your body has ample stores of.

"There has been a big debate in the media on which is better," says performance nutritionist James Collins. "Ultimately, carbohydrates and fat are both important elements during training. Fat is the preferred fuel source during lighter, low-intensity training, whereas carbohydrates are ideal for harder, high-intensity training."

Collins, whose credentials include a stint as head nutritionist for Arsenal FC and advising Team GB ahead of the London and Rio Olympics, believes a good marathon diet is finding the right balance between carbs and fats for fuel, protein for recovery and fluids for hydration. The trick is to find out what works for you and be consistent.

It's a similar story for race day — stick to what you kn ow. Changes could lead to the infamous runner's trots. Tried and tested foods will help you focus on the job at hand — putting one foot in front of the other for 26.2 miles.

Marathons to travel for

Safaricom Marathon
Kenya's Lewa Wildlife Conservancy is home to many endangered species, and for one day each year, it hosts herds of runners too. Temperatures can reach 30–35°C at altitudes of 5,500ft. 30 June.

Great Wall Marathon
Want a one-off experience? Try tackling the 5,164 steps of the Great Wall of China. The climbs are brutal, but the views of the wall snaking through the countryside are hard to beat. 19 May. 

Midnight Sun Marathon
Each year, the Norwegian city of Tromsø hosts the word's northernmost marathon, 250 miles above the Arctic Circle, where in summer the sun never sets. The race starts at 8.30pm. 16 June.


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