Diet for Marathon Runners

Endurance Sports Nutrition

In addition to training, marathon runners must also focus on their diet.

A healthy diet will significantly influence your marathon training and race-day performance.

 An adequate diet in terms of quantity and quality, before, during and after, training and competition, will maximize results for marathon runners.

 The following 4 steps will help marathon runners develop a diet that will maximize their performance.

 Step 1 – Basic Nutrition Needs
Ensure the basic diet needs of the marathon runner are met – this is the foundation of any sports nutrition plan. More

Step 2 – Training
Marathon runners need to plan for increased nutrition requirements during training. The training diet holds the most potential for improving your marathon performance. More

Step 3 – Competition
Marathon runners need to develop their own diet strategy for competition. This is when you will implement the diet plan that you have practiced in training. More

Step 4 – Special Nutrition Issues
Be aware of special diet issues for marathon runners in order to make decisions to maximize performance.

What are the basic diet requirements for marathon runners?

  • Basic nutritional requirements are the foundation for healthy eating.
  • When you eat enough food to meet basic requirements, you provide you body with just enough nutrients for energy and to maintain health and normal function.
  • Growth, tissue damage, repair and stressful environments can increase nutritional needs.

What happens if marathon runners are not meeting basic diet requirements?

  • If marathon runners are not eating enough food to meet basic diet requirements their bodies will not get enough nutrients and nutritional inadequacies may start to occur.
  • Symptoms include chronic tiredness, frequent illness, poor concentration, poor performance and poor recovery.

What are the nutrients a marathon runner needs and what do they do?

Provides the superior fuel source for muscles during physical exercise. Carbohydrate is stored in limited amounts only and needs to be continually replenished. To learn more about carbohydrate and carbo-loading click here

Helps keep bowels regular and can help reduce blood cholesterol. Marathon runners may need to decrease fibre pre-competition to prevent gut problems.

Essential in the growth and repair of all body tissues, including muscle and bone; hormone and enzyme production; optimal immune function. Protein is also a minor source of energy. To learn more about protein click here

Provides the most concentrated and largest source of energy. Fat provides most of the energy for daily activity. Required for normal growth and healthy skin, production of certain hormones, structural component of body cells, supply of fat-soluble vitamins A, D, E and K. To learn more about fat click here
Prevents dehydration, helps cool the body and acts as a transport medium. Stored in the body in limited amounts. To read more about water, sports drinks and other fluids click here

Vitamin B Complex
Involved in carbohydrate, protein and fat metabolism. B12 and folate are required for red blood cell production.

Vitamin C
Enhances iron absorption, acts as an antioxidant (antioxidants ‘mop up’ free radicals, preventing cell damage), increases energy production, is necessary for the synthesis of collagen for the formation of connective tissue and bone.
Vitamin E
An antioxidant that helps prevent cell damage caused by free radicals. Free radicals are substances that cause cell damage. As a result of greater oxygen uptake athletes have higher levels of free radicals. Antioxidants ‘mop up’ free radicals, preventing cell damage.


Required for the formation of haemoglobin and myoglobin, the oxygen-carrying components of red blood cells and muscle cells respectively. Required for energy reactions to take place. To learn more about iron
click here

Required to build and maintain strong bones and teeth, essential for muscle function, blood clotting and nerve transmission. To learn more about calcium click here
Essential for normal growth, reproduction, immune system function and energy production in muscle cells.

Guidelines for marathon runners to meet basic diet requirements
Eat a variety of food from each of the four major food groups each day (breads and cereals; vegetables and fruits; milk, dairy products and milk substitutes, especially low-fat varieties; lean meats, poultry, fish, eggs, nuts and meat substitutes like lentils, chickpeas, soy beans and other beans).

Prepare meals with minimal added fat (especially saturated fat) and salt. To read more about salt click here

Choose pre-prepared foods, drinks and snacks that are low in fat (especially saturated fat) and salt. To learn more about fat click here
Maintain a healthy body weight by regular physical activity (which should not be a problem for marathon runners!) and by healthy eating. To read more on weight management for marathon runners click here
Drink plenty of fluids each day. To read more on fluids click here
If drinking alcohol do so in moderation. To learn how alcohol can affect your athletic performance click here

Remember that the above are general nutrition guidelines that provide the foundation for a healthy diet. As a marathon runners you need to get your basic diet right before you begin to work on your training and competition diet.

You as a marathon runner should eat a wide variety from each of the food groups (breads and cereals; vegetables and fruits; milk, dairy products and milk substitutes; lean meats, poultry, fish, eggs, nuts; fluids) to ensure you get the nutrients your body needs. In doing this you will also have interesting and satisfying meals.

To review a table of examples of a serving of the various food groups and the daily level necessary to meet your basic nutritional requirements
click here

Are you meeting your basic nutritional requirements?

Rule up a chart under the headings;

  • Breads and cereal (recommended serves – 6)
  • Vegetables and fruits (recommended serves – 2 fruit & 3 vege)
  • Milk, dairy products and milk substitutes (recommended serves – 2)
  • Meat and meat substitutes (recommended serves – 1)
  • Fluids (recommended serves – 8 cups)

Record what you eat for a day in the food groups. Tally the number of serves you had from each food group and compare with the recommended serves.

If you have not met the recommended servings you need to begin by trying to meet these basic diet requirements. Supplements are not the answer! Often when marathon runners reach for supplements they choose supplements that are not appropriate for their needs anyway. Marathon runners sometimes forget that the goodness they try to get from supplements has been scientifically proven to be of most benefit when found in its natural form in food.

Write down one goal that you will work on over the next week to improve your baseline nutrition. For example: ‘My goal this week is to increase my daily servings of vegetables from one to three.’

Write down your ideas for a meal plan that will enable to you meet your nutritional goals.

Why do you need a nutritional plan for marathon training?
You need a nutritional plan for marathon training to ensure you are meeting your body’s increased nutrient requirements. These increased nutrient requirements will depend on your training volumes, frequency and intensity. Your requirements will also vary during the different training phases of the year. The skills you learn when designing your nutritional plan for training can be used to individualize your plan.

Following sound nutrition practices is most important during marathon training. If you think about it, you spend most of your time training and this is largely what determines your performance in competition. Good nutrition will help you maximize your training and your competition performance. Your nutrition on competition day is just fine-tuning of your training nutrition. To read more about nutrition during marathon training click here

Competition Nutrition
Competition nutrition is an extension of training nutrition. The correct nutritional strategies before, during and after competition will help you achieve the ultimate goal: your best possible marathon performance.

Planning your meals for competition is a good way of focusing on your marathon event. By knowing when, what and how much you are going to eat and drink, you can be confident that you have the best possible nutritional preparation. Planning ensures that the food you want is available, whether you’re at home or traveling. To read more about nutrition during competition click here