What to Eat Before the London Marathon: Top Nutrition Advice for Race Week
The London Marathon 2026 is only 10 days away, and with just over a week of training left to fine-tune your approach, now is the time to make sure you are fuelling with the right nutrition!
Whether you are taking to London’s streets on Sunday 26th April, or you are preparing for the wider marathon season, the nutrition experts at healthy meal prep service Prep Kitchen have provided must-know tips on how to carb load and leave room for protein ahead of a marathon.
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Dan Osman, Performance Nutrition Specialist at Prep Kitchen, shares what he wants runners to know ahead of the London Marathon:
“People are more health-aware and performance-conscious than ever, but that also brings with it some confusion and anxiety about getting things ‘wrong’.
“We see every day runners instinctively gravitate toward higher carbohydrate meals in the lead-up to the London Marathon, and for good reason too.
“There is strong evidence that eating carbohydrates before a race improves the runner’s experience, including greater endurance and performance metrics such as speed and recovery time.
“Carbohydrates help sustain energy and are the body’s preferred fuel for long-distance running.”
Dan explains why carb loading works & why it’s crucial right now:
“Carb loading is one of the most well-researched and consistently validated strategies in sports nutrition.
“In the two to three weeks before a marathon, the body becomes exceptionally efficient… at storing glycogen in the muscles and liver.
“Our livers alone store between 100g and 120g of carbohydrates, which is 400–480 calories of energy.
“There are a multitude of changes and enhancements to our bodies after the long road to race day, too! We become better fat-adapted, which is also crucial for endurance activities; glycogen conservation improves, delaying fatigue. “Bonking” and “hitting the wall” take longer.
“If you take advantage of that window and significantly increase your carbohydrate intake, you essentially arrive at the start line with a full tank. Missing that window is a missed opportunity to perform and feel your best on race day, or, at best, start at a disadvantage.”
Dan also shared some numbers which might surprise runners:
“What is often misunderstood is how high carbohydrate intake actually needs to be to make a difference.
“Some athletes target between 5 and 12 grams of carbohydrate per kilogram of body weight per day, and during peak loading, 10g and 12g per kilogram.
“For a 70-kilogram runner, that is between 560g (2,320 calories) and 840g (3,360 calories) of carbohydrate alone daily.
“Hitting those numbers from whole-food sources, without it becoming a full-time job, requires meals that are genuinely rich in quality carbohydrates and carbohydrate density.
“Many struggle with food volume (the sheer mass of food required) and the digestive processes needed to assimilate and use all that food. You want nutrient and caloric density without the digestive work or the digestive upset. No one needs an overloaded and upset stomach on race day!
“Being more astute about food choices and meal timing ensures you get as much caloric and energy ‘bang for your buck’ as possible.”
Dan also warns runners not to neglect protein:
“Without sufficient glycogen stores, the body’s next option is to break down muscle proteins for fuel.
“These final weeks are the last real opportunity to repair and reinforce. Protein intake needs to stay high even as training volume drops. I recommend aiming for a minimum of 1.6g to 2g of protein per kilogram of body weight daily, right through to the start line.”
Dan’s final advice to runners:
“You have done the hard work; now is the time to enjoy the day. What you do with your nutrition, your rest, and your sleep can absolutely make the difference. Eat well, sleep well, and trust your preparation.”
