Diet before, between, and after a marathon

The most important cycling event in Slovenia, the Franja marathon, is approaching. To honor this event, we tackle the important question of what to eat before a marathon.

One of the most important factors in an athlete's preparation is a proper diet. An inappropriate diet can ruin even the best preparations. With the assistance of a dietician from the Human Performance Center, Blaž Grmek, we prepared guidelines for a proper diet in the days before and during the marathon itself.

We divide the diet into four segments:

• the first segment is the diet in the days before the race when we wish to make sure we are as rested and light during the race, as the body weight significantly impacts the result;
• the second segment is replenishment of glycogen stores, which is done a day before and the morning before the event;
• the third segment is diet and hydration during the marathon;
• the fourth segment is fast recovery after the race.

Recovery drink Regen by Nduranz

How to make sure we are rested and light on the day of the race?

Three days before the event it is very important to reduce the intake of high-fiber foods and replace it with lower-fiber foods.

Dietary fiber is indigestible, which is why a high intake of fiber before the marathon can cause digestive issues (bloating, diarrhea), and we can lose up to two kilograms of body weight.

Meals should consist of mostly carbohydrates (emphasis on low-fiber foods) and protein (20 to 40 grams per meal). The intake of fat should be limited, as fat is not required in this phase.

The list of foods which need to be limited

• whole grains and related products (wholemeal bread/pasta)
• oatmeal
• wholegrain/brown rice
• legumes (beans, lentil, chickpea, pea, peanuts)
• potato, sweet potato
• fresh/raw vegetables (e.g., broccoli, carrot, cabbage)
• dry fruit (dates, prunes, dried apricots)
• seeds (linseed, chia seeds, sunflower/pumpkin seeds)
• nuts (almonds, macadamia, hazelnuts, pistachios)

Better alternatives

• white rice
• rice cakes
• rice noodles
• groats
• white bread
• white pasta
• couscous
• cooked, easier to digest vegetables (tomato (sauce))
• fruit (peach, nectarine, watermelon)
• honey
• marmalade
• fruit juices
• Haribo gummy bears
• lean meat (turkey, chicken, rabbit)
• red meat (pork, beef)
• fruit/plain yoghurt
• skimmed milk products (skyr, quark, Greek yoghurt, cottage cheese)
• low-fat cheese
• whey powder
• eggs
• egg whites
• fish (salmon, mackerel, sardines)
• seafood (shrimp)
• tofu

How to replenish the glycogen stores?

Take the day before the marathon off or have your training session in the morning. The thing is, we want as much time as possible to replenish the glycogen stores. If you were to train in the afternoon, even a low intensity training, you would greatly diminish the ability to replenish the stores of carbohydrates.

So, the day before the event, a very high intake of carbohydrate foods is important. We have to ingest 10 to 12 grams of carbohydrates per kilogram of body weight. The goal is to replenish the glycogen stores (especially muscle glycogen) and enable the body to properly prepare for the intense physical activity. The intake of fat should be as low as possible, while you can ingest protein normally with every main meal.

Adequate (carbohydrate) foods

• white rice
• rice cakes
• rice noodles
• groats
• white bread
• white pasta
• couscous
• banana
• honey
• marmalade
• fruit juices
• fruit/plain yoghurt
• Haribo gummy bears

In the morning, before commencing the race, the meal should be rich with carbohydrates. It should contain as little fiber as possible and different types of sugar. Our recommendation is rice pudding, cooked in lactose-free milk with added sugar and chocolate powder. Try to ingest 2 to 4 grams of carbohydrates per kilogram of body weight.

Period during the marathon

Even if carbohydrate stores are full, they will deplete quickly during the marathon. This is why ingesting additional carbohydrates during the race is crucial. To the most intense athletes we recommend two energy units (Nrgy Units) per hour. This means one bottle of Nrgy Unit Drink and one Nrgy Unit Gel. Women and less experienced competitors should be fine with one Nrgy Unit per hour, which means one gel or one sports drink per hour.

Period after the marathon

Same as before and during the event, it is important to ingest carbohydrates as soon as possible after the event in combination with a quality source of protein to enable efficient and quick recovery.

You can use a recovery drink such as Regen which has an appropriate ratio of carbohydrates and protein (50 g of carbohydrates and 30 g of whey protein isolate) and stimulates rehydration, replenishment of glycogen stores, and recovery of the damaged muscle tissue.

For the first four hours after the recovery drink ingest one meal which contains 1 to 1.4 grams of carbohydrates per kilogram of body weight or two meals rich with carbohydrates that contain around 20 grams (or more) of protein per meal. 

Meal examples

The amounts for the third and second day before the marathon are not given because the intensity and amount of training, and consequently energy requirements, of individuals may vary greatly.

Three days before the marathon

Low-fiber diet

• carbohydrates (emphasis on low-fiber foods)
• protein (20 to 40 grams per meal)
• limited intake of fat

Breakfast example

• toast (white wheat)
• skyr/quark
• chicken breast
• green bell pepper/corn (limited intake)

Snack example

• skyr, quark, whey or any dairy product that contains around 10 grams of protein per 100 grams
• piece of fruit

Lunch example

• rice with chicken or beef
• cooked carrot or lamb's lettuce (limited intake)
• tuna (drained) or chicken
• corn
• light cheese
• piece of white bread

Dinner example

• meat of choice or fish
• carbohydrate side dish (e.g., white pasta)
• vegetables of choice (any vegetable that doesn't cause bloating or digestive issues) (limited intake)

Two days before the marathon

Breakfast example

• rice/groats cooked in water
• cacao (BenQuick)/honey/marmalade/banana
• whey/skyr/quark/any dairy product that contains around 10 grams of protein per 100 grams

Snack example

• protein drink or shake (whey with water)
• piece of fruit

Lunch example

• pasta with shrimp
• vegetables of choice (any vegetable that doesn't cause bloating or digestive issues) (limited intake)

Dinner example

• lean meat
• carbohydrate side dish (e.g., couscous)

One day before the marathon

For the last day before the marathon and the day of the marathon we indicate examples of meals for a male athlete weighing 70 kilograms and a female athlete weighing 60 kilograms.

One day before the marathon we must perform carb loading according to the following formula:

carbohydrates (with low fiber) + protein (under 20 grams per meal) - fat (minimal intake)

A male athlete weighing 70 kilograms should ingest on the day before the marathon 700 to 840 grams of carbohydrates (70 kg x 10/12 g CHO).

A female athlete weighing 60 kilograms should ingest on the day before the marathon 600 to 720 grams of carbohydrates (60 kg x 10/12 g CHO).

In regard to the maximal intake, female athletes can ingest the same amount as men, but we indicate alternatives for the minimal intake. One option is to remove one of the meals of male athletes, for example the afternoon snack. The other option is to reduce the ingested amounts. You can adjust the amounts yourself, we reduced the intake of rice/groats/pasta because this value is the easiest to adjust.

Breakfast example

Ca. 180 g of carbohydrates for men and 148 g for women.

• rice/groats (at least 150 g of raw mass for men and 100 g for women) cooked in water
• honey/marmalade (at least one large spoon, ca. 50 g)
• whey/skyr/quark/any dairy product that contains around 10 grams of protein per 100 grams (one or two spoons)

Morning snack example

Ca. 145 g of carbohydrates for men and 130 g for women.

• cooked rice/groats (at least 100 g of raw mass for men and 80 g for women)
• honey/marmalade (at least 2 large spoons, together ca. 100 g)

Lunch example

Ca. 144 grams of carbohydrates for men and 107 for women, sauce not included.

• white pasta (at least 150 g of raw mass for men and 100 g for women)
• low fat tomato/cream sauce (one ladle)
• rice cakes (at least 40 g or ca. five cakes)

Afternoon snack example

Ca. 97 g of carbohydrates for men and 82 g for women, sauce not included.

• lunch leftover pasta (additional 100 g of raw mass for men and 80 g for women)
• small amount of sauce

Dinner example

Ca. 134 g of carbohydrates for men and women, cottage cheese not included.

• rice cakes (at least 80 g or ca. ten cakes)
• honey/marmalade (at least two large spoons, together ca. 100 g)
• cottage cheese (one or two spoons)

Meals on the day before the marathon contain ca. 700 grams of carbohydrates for men and 600 grams for women, which represents an approximation of the minimal intake.

Emergency meal - in case you cannot meet the required intake of carbohydrates, you can use, based on your personal need, Haribo gummy bears or sweet non-carbonated drink such as ice tea.

The day of the marathon

On the day of the marathon we continue with carb loading.

Breakfast example

Ca. 150 g of carbohydrates for men and 120 g for women.

• rice/groats (at least 150 g of raw mass for men and 110 g for women) cooked in low-fat milk (1.5 % fat or half 3.5 % fat milk and half water)
• sugar (one spoon)
• cocoa (two spoons)

Snack example, one hour before the marathon

• banana (one piece)
• Haribo gummy bears (one fist) or candy bar (one piece)

Summary