The Ultimate Guide For Crafting The Perfect Pre-Race Meal to Run Your Fastest Marathon

Estimated read time: 3.65 minutes

Hey! - Performance Nerds, Jonah here. 🤓

Many runners make mistakes with their pre-race meal. They destroy 16 weeks of hard training in 10 minutes.

Why? Because they eat the wrong foods on marathon morning.

Today, you’ll learn everything about pre-marathon meals:

• How much and when to eat on race day

• Which foods to eat and which to avoid

• Sample pre-race meals

Enjoy this week’s guide, the nerdy question, and my favorite sciencey finds.

Don’t forget to reply if you need advice for your upcoming race! 🏃‍♀️💨🧪

1) Exactly how much and when should you eat?

You’re not eating enough carbs on race morning.

Aim for 2-4 grams of carbs per kilogram of body weight (0.45-1.82 grams per pound) 2-4 hours before your race.

Have your pre-race meal at least 2 hours before the start. This gives your body time to digest, replenishing your liver glycogen (more on this later) and prevents stomach issues.

If your marathon is 4 hours away, go for the higher end—closer to 4 grams.

If you’ve had stomach issues before or are less than an hour from your race, stick to 1-2 grams of carbs per kilogram.

2) What should you eat?

The right pre-race foods can improve your marathon time by up to 10%🚀

The goal is to maximize your liver glycogen stores. Here’s why:

Your body has two main places for storing carbs:

• Muscles (as muscle glycogen) 💪

• Liver (as liver glycogen)

Your muscles are inactive overnight, so their glycogen is not used up. A good carb load in the days leading up to your race is essential to fill those stores.

But your brain and vital organs are active! This depletes your liver glycogen as it provides energy to those organs. 🧠

You need to replenish your liver glycogen the morning of your race. Your liver then sends those carbs to your muscles for extra energy during the marathon. ⛽️

Pre-Race Carbs Quick Tips

• Eat easy to digest carbs

  • These fill your liver glycogen stores quickly, especially since you'll be running soon!

• Liquid and solid carbs both work

The Secret Carb Source You Need: Fructose

Want to slash 7% off your marathon time? Meet your new best friend: Fructose!

You have two main carb sources:

• Glucose (Rice, Bread, Pasta, Bagels)

• Fructose (Honey, Juice, Jelly)

Fructose is better at replenishing your liver glycogen, which is key for your pre-race meal.

On race morning, aim for a 2:1 ratio of glucose to fructose. For every 2 grams of glucose, eat 1 gram of fructose.

For example, if you're aiming for 100 grams of carbs, target 67 grams of glucose and 33 of fructose.

Don’t eat these foods!

Your pre-race meal is like me when my mom texts, “Just picked up ice cream.”

It needs to get to where it’s going fast - I sprint home for ice cream and set a new mile PR in Birkenstocks (someone tell strava). Living with my parents has its perks! 🍦

Your morning carbs should reach your liver quickly.

Avoid foods that slow down digestion or cause stomach issues, like high-fiber veggies, protein, and fat.

Two hours before your race? You’re team speedy carbs. 🍝

3) Sample Pre-Race Meals for Fast Marathons

Practical Summary

• Carb Intake: 2-4 grams of carbs per kilogram of body weight (0.45-1.82 grams per pound) 2-4 hours before the race.

• Carb Sources: Eat easy-to-digest carbs to quickly fill liver glycogen stores

  • Both liquid and solid carbs work

• Fructose: 2:1 ratio of glucose to fructose (67g glucose and 33g fructose for 100g total carbs)

• Avoid Slow-Digesting Foods: No high-fiber foods (like vegetables), protein, and fat, as they can slow digestion and cause stomach issues

80/20 Rule is A Giant Mistake for Marathoners

Did you miss my video about the why the 80/20 rule is a giant mistake for marathon runners? You can find it below!

I won’t lie. These videos take me a while to make. If you find it helpful, share it on your story or with a friend. It helps me a ton!

Don’t forget: You + Science = AWESOMENESS 😎

Yours in science,

Jonah

Please email me directly if you’re interested in references for this week!