Nutrition for Marathon Runners

I notice that there are more and more marathon events organized by Adidas, Nike, Standard Charter, etc... but there are lots of inexperience runners.
They do not have any professional coach nor a nutritionist to guide them. It is still ok if you do not have a coach but it is very dangerous without a nutritionist or not knowing what kind of diet to undergo before the run.

So i decided to write this article to share some nutrition advice to all.

A training marathon runner should be consuming a diet that is composed of between 65% carbohydrates - 25% protein – 10% fat. So what type of carbohydrates should we take, the truth about it is that they are all different. Some supply energy very quickly while others provide a slow, steady stream of energy. Therefore 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 carbohydrate 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. When your blood glucose is stable, you can run for a longer period of time.
You may visit here to find out the GI of the food that you consume.

High GI foods on the other hand give your blood glucose a boast. This causes your body to release insulin which pulls the carbohydrate out of your bloodstream and your blood glucose dropped. For that reason, you should be eating low GI carbohydrate during your training periods. Low GI carbohydrate are also best for general health and weight maintenance.

A training marathon runner should be consuming a diet that is composed of about 65% carbohydrates - 25% protein – 10% fat. So what type of carbohydrates should we take? The fact about it is that they are different type of carbohydrates. Some supply energy very quickly while others provide a slow, steady stream of energy. Therefore 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 carbohydrate 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. When your blood glucose is stable, you can run for a longer period of time.
You may visit here to find out the GI of the food that you consume.

High GI foods on the other hand give your blood glucose a boast. This causes your body to release insulin which pulls the carbohydrate out of your bloodstream and your blood glucose dropped. For that reason, you should be eating low GI carbohydrate during your training periods. Low GI carbohydrate are also best for general health and weight maintenance.

Recommended Diet Plan
You should start your diet plan 2-3 weeks before your run. Up until the final week, you should maintain a diet that is similar to your training diet - about 65 to 70% carbohydrates

During the week before your race, you need to change your diet plan to the following :

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.

This is to help to increase your muscles' carbohydrate storing ability. The best types of carbohydrate to eat during this period are low GI carbohydrate so that your blood glucose levels maintain a steady state.

Day 1 – Exercise Duration – 60 inutes, 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

During the Race Day
Wake up early in the morning and eat a light meal of low GI foods. Do not fast. You will need to replenish liver glycogen stores before your race. 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.

During your race, you need to take in high GI foods, it will 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

Summary
During training, eat a high carbohydrate diet composed of low GI foods.

During your last week, decrease your carbohydrate 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.