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Marathon Nutrition Plan

Posted by: on January, 22 2013

Marathon Nutrition – Nutritional Tips for Running Your Best Marathon


Imaging a marathon training program in which your run the same distance, at the same pace every day. You obviously would not perform very well with a training routine like that. Marathon nutrition is very similar. Your training program almost certainly follows some sort of periodized schedule where your workouts are modified as you progress though your program. Your nutritional plans should be periodized just like your marathon training program.

There are three basic stages in your marathon nutrition plan. They are: marathon training nutritional plan, marathon taper nutritional plan and marathon race day plan.

Marathon Training Nutritional Plan

Leah is a client who approached me not long ago about training for a marathon. She had attempted a marathon a few years ago and struggled so severely during training that she quit. She said that she was constantly tired and did not have the energy for daily activities, much less marathon training. She thought that she may have been training improperly. I took a look at her training log and found that the program she was following was a basic, but essentially solid training schedule. I discovered her mistake when I asked about the nutritional plan she was following. She told me she was trying to lose weight at the time and was following one of those popular low-carb diets. I placed her on a high carb diet and she went on to successfully complete not only her first marathon several more.

Carbohydrates are the fuel for your body. Marathon training burns a lot of carbs. The exact number of carbohydrates you burn per mile depends upon your fitness level, experience level, pace and running economy, but most marathon runners average around 110 calories per mile with about 75% of those calories coming from carbohydrates. A typical runner can store approximately 1800 calories worth of carbohydrate in their muscles, liver and blood. That amount of carbohydrate will be depleted in about 22 to 23 miles which explains why most marathon runners “hit the wall” at that point in the race.

A training marathon runner should be consuming a diet that is composed of between 65% and 70% carbohydrates. A typical marathon training diet is one that is around 65% carbohydrates – 25% protein – 10% fat. Most runners believe that a carb is a carb. The truth is that all carbs are not created equal. Some supply energy very quickly while others provide a slow, steady stream of energy. Carbohydrates are classified by numbers between 1 and 100. This is called the glycemic index (GI). Simple carbohydrate is high on the GI and gets into you system very quickly. Complex carbs are generally lower on the GI and filter into your system more slowly. Foods that are low on the GI list tend to keep your blood glucose level and give you a steady supply of energy. You will be able to maintain your training runs for longer periods of time if your blood glucose is stable. High GI foods cause a roller coaster effect. After eating a high GI food your blood glucose will soar. This causes your body to release insulin which pulls the carbs out of your bloodstream and your blood glucose plummets. For that reason you should be eating low GI carbs during your training periods. Low GI carbs are also best for general health and weight maintenance. See The Glycemic Index for a list of low and high GI foods.

Marathon Taper Nutritional Plan

You will be tapering for your marathon for two to three weeks. Up until the final week of your taper, maintain a diet that is similar to your training diet or about 65 to 70% carbohydrates, but remember to decrease serving sizes during this time. Your training mileage is dropping fast and so does your calorie requirements. You do not want to put on a couple of extra pounds before your race. During the week before your race you should start a super compensation eating plan. Super compensation involves depleting your muscles of carbohydrate followed by a loading period. To carry out this plan follow the guide presented below. Decrease carbohydrate intake gradually from 60% to 40% of your total calories on days 1 through 3. Decrease your running duration from 60 minutes to 30 minutes during that period. On the following three days increase your carbohydrate intake to 70% of total calories and decrease your running duration from 20 minutes to total rest. The result will be muscles that are “maxed out” in their carb storing ability. The best types of carbs to eat during your marathon taper are also low GI carbs so that your blood glucose levels maintain a steady state.

Final Taper Week

Day 1 – Exercise Duration – 60 minutes, Carb intake – 60%

Day 2 – Exercise Duration – 40 minutes, Carb intake – 50%

Day 3 – Exercise Duration – 30 minutes, Carb intake – 40%

Day 4 – Exercise Duration – 20 minutes, Carb intake – 70%

Day 5 – Exercise Duration – Rest, Carb intake – 70%

Day 6 – Exercise Duration – Rest, Carb intake – 70%

Day 7 – Race Day

Race-Day Plan

Your marathon day eating plan has two phases. Pre-race eating and fueling during your race. Get up early on race morning and eat a light meal of low GI foods. Do not fast. You will need to “top off your tank” and replenish liver glycogen stores before your race. The addition of some fats along with some low GI foods will also help keep your blood glucose stable. An example would be two pieces of whole grain toast with butter and a banana. Avoid high GI foods on race morning because it can cause your blood glucose to fall and you will end up using a very high percentage of liver glucose for energy early in the race. If that happens you will pay the price at mile 20.

During your race it is time to eat high GI foods. The high GI foods quickly release energy and give you a fast energy boost. Good high GI foods that are convenient foods on the run are energy bars, energy gels and sports drinks.

The Wrap Up.

During training eat a high carbohydrate diet composed of low GI foods. During your last taper week decrease your carb intake briefly before increasing it back to 70% of total calories in conjunction with decrease training volume. Eat a light pre race meal of a combination of low GI foods and fat. While running start taking in high GI foods for fast energy replacement.