Marathon Diet Plan - Warning: For Serious Runners Only!

If you’re thinking of joining a marathon and wondering how to get yourself in top form, then read on. In this article, we’ll share a marathon diet plan that you can follow until the big day itself. 

Why Should You Follow A Marathon Diet Plan?

Whether you’re a beginner or a veteran, endurance training and ensuring that you have enough energy to fuel and recover is crucial when preparing for a marathon.

Most runners would spend hours on physical training but overlook proper nutrition. There are some very real consequences to this.

For example, runners are highly susceptible to hypoglycemia. This is when the body’s blood sugar drops to a below normal level, and in severe cases could lead to death when left untreated.

Symptoms of hypoglycemia include headaches, severe sweating, palpitations and trembling. It’s easy to dismiss these symptoms when you are already tired and sweating after a run. 

Because of this, it’s important to follow a proper diet.

So what should a serious runner eat in preparation for a marathon? 

Read further for a marathon runners’ diet plan example.

Preparing for a Marathon 

High Protein Meal

Image Source: The Iron You

Your body needs to be prepared - really prepared- before running a marathon, and your eating habits must support this preparation. 

The marathon diet plan should be rich in proteins, healthy fats and complex carbohydrates. 

At least 10 weeks before the marathon, instead of eating three big meals, switch to smaller food portions eaten five or six times a day. 

This will stabilize your blood sugar and maintain an elevated metabolism. Maintaining an elevated metabolism trains your body to use your fat reserves as a fuel source.

Check out some of these healthy, easy-to-make, high protein meal recipes:

14 High-Protein Meals That'll Fill You Up for Hours

27 High-Protein Dinners You Can Make In 20 Minutes or Less

Pre-Marathon diet plan: Protein & Hydration

Drink more than 6 to 8 glasses per day and an additional 8 ounces for every 20-minute run.

Understand your sweat rate so you can adjust your fluid intake.

Around 200 grams of chicken per day is recommended because runners need protein more than non-runners.

Without protein, the body can’t maintain and build lean muscles.

15% of your total calories should come from protein and 60-70% should come from carbohydrates.

21 High Protein Recipes from BBC Good Food

20 Delicious High-Protein Foods

Before deciding to load up on carbohydrates for work-out energy, remember that carbo-loading might not work for you.

Some runners perform better and train efficiently after loading on carbs but it may lead to unhealthy eating habits after your training period especially if you load up on simple sugars instead of complex carbohydrates.

Complex carbohydrates include cereal, oatmeal, whole grains, brown rice, etc.

Complement this diet plan with strength training like ball exercises or calisthenics. Remember that endurance training does not require you to build muscles.

During training, you’ll also surely need comfortable, but durable workout clothes that will allow you to move freely.

During the race, you won’t have a lot of options, so don’t forget to check out the nutrition handed out during the marathon and prepare for this as well.

Most races provide electrolyte drinks, water or energy bars on the course. But if you have the time, pack some healthier meals.

Protein Snack Pack - Lunch Meal Prep

Marathon diet weeks before the big day

Carbohydrate-loading Diet Plan

Image Source: Lady & Pups

Three weeks to a week before, gradually increase your carb intake in order to build up glycogen reserves.

Muscle glycogen comes from eating foods rich in carbohydrates like pasta, low-fat dairy, legumes and sweet potatoes.

Carbohydrate-loading Diet Plan from the Mayo Clinic

The Best Foods to Build Glycogen

Pair this up with ginger tea because this will lessen muscle soreness, so getting this in your system can help prevent muscle cramps in the middle of a run.

Anti-Inflammatory Diet from WebMD

The Diet Plan

For breakfast, we recommend a complex carbohydrate with protein and fruits like whole grain cereal with Greek yogurt and fruits or a smoothie made with fruits, milk and vegetables.

Do not confuse smoothies with juices in grocery shelves. Stay away from store-bought juices because they are full of sugar. To curb your cravings and hunger pangs, supplement this with a snack of fruits, nuts and crackers.

33 Low Sugar Smoothies That Are Actually Delicious

A week before the marathon is not the best time to check out the new fusion restaurant and to test your culinary skills using exotic ingredients.

During this period, consume safe and easy to digest options only. It is best to stay at home and cook for yourself, but keep your hands away from the curry and chili pepper - unless you’re looking for a reason to chicken out from the marathon.

After a run, make sure to eat a recovery snack with carbs and protein within the next 30-45 minutes. This is when your body is most responsive and nutrients will be used to repair and rebuild muscles.

Stop any long distance runs two weeks before the race to give time for your muscles to recover. Drink plenty of water. If you are tempted to have a sugary drink, use cucumber or lemon slices to add flavour to your water.

Three days before the marathon, cut back on fat and load up with about 70% more carbohydrates. This is going to make up your energy reserves so scale back on your training.

Relying on food may not be enough. Focus on sleeping a week before the race and for quicker muscle recovery and faster nutrient absorption, supplement your marathon diet with dietary supplements to ensure you are not lacking important nutrients needed by your body.

Pre-workout Supplements

Image Source: Healthy Living

The Best Pre-workout Supplements for Real Athletes

Guide to Pre-workout and Post-workout Supplements

Marathon nutrition during race day

Diet Plan

Image Source: BMO Vancouver Marathon

You have come this far and you are still decided to go. Congratulations!

Today is the day that you’ve worked hard for.

Check the weather forecast and prepare your running gear.

Make sure to wear comfortable running pants and shoes that you’ve already broken into. 

Tip#1: Check your urine color when you pee and if it’s still dark, that just means you need to drink more water.

The pre-race breakfast should be rich in carbohydrates, like a bagel with peanut butter or toast with yogurt, and should be taken 3-4 hours prior. This allows the food to be digested and stored. 

Bananas and boiled eggs are also delicious options.

Keeping your energy level is important during the race so you need to refuel every 30 to 45 minutes. Take at least 30 grams of carbs every hour even if you do not feel it is needed.

During the race, take just enough carbohydrates and fluids. Too much of both may lead to an upset stomach.

Foods to avoid when training for a marathon

High Caffeine Energy Drinks

Image Source: Hilbert Community

High caffeine energy drinks may lead to dehydration.

Studies show that only 3mg per kilogram, about 150mg of caffeine for a 50 kilogram person; is needed to give a boost in performance.

A can of energy drink has between 80mg to 180mg of caffeine and an ounce of espresso has about 63grams of caffeine.

So, stay away from coffee, soda and energy drinks. If you cannot let go of your daily coffee, try decaffeinated.

Drinks with electrolytes are recommended after a long run. However, electrolytes help with the quicker absorption of nutrients. 

High Sodium Food or Drinks

High sodium food or drinks can trigger cramps. Packaged snacks and some nuts are usually packed with a lot of sodium. Sugary foods can also cause cramps and can cause your sugar levels to spike.


Alcohol is also dehydrating and can affect your blood sugar, so abstaining from it is still the best choice.

Because alcohol is a diuretic, a shot of beer or wine will cause a person to produce roughly 1ml per kilogram more than your normal output.

Dehydration decreases your sweat rate and may cause spasms and cramps during training.

So, you can the booze for until after the marathon, if you still want to.

Wrapping Up

You are now off to a great start! Remember, you are preparing your body not only for the marathon but also for the aftermath.

If we missed anything or you would like us to add more, let us know your suggestions!

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