Marathon. . . all you should know before the big race !!!

Marathon. . . all you should know before the big race !!!

The marathon day is only a breath away and the preparation for either professionals or amateurs is at the final stage. Although the hard training is the main factor for success, nutrition is also important in athletic performance. Below you will find some guidance that will help you optimize your nutrition for have a successful race.


A short overview . . .


The requirements for carbohydrates, proteins, vitamins, minerals and liquids vary accordingly in each individual (based on gender, age and daily exercise).

There should be an increase in total carbohydrate and energy intake during long training sessions and a decrease in intake when volume and intensity decrease ( recovery days).

Nutrient dense, carbohydrate rich foods (such as whole-grain breads and cereals, starchy vegetables, fruit, dairy) should be the main fuel for the athlete. When the needs are higher, athletes can also include carbohydrate rich drinks (e.g. sports drinks, energy gels) during heavy trainings to improve performance. Strategic intake of carbohydrate rich foods/drinks soon after training will aid rapid muscle glycogen repletion, particularly on double trainings on the same day. Including protein rich foods throughout the day will promote the recovery of muscles, and protein synthesis and the production of red blood cells as part of the repair and adaptation process.



What should you eat/drink before the race

The main factors that cause fatigue during a marathon race are fuel depletion (carbohydrate) and dehydration. Therefore, both of these factors should be addressed to ensure that the race is completed at the desired intensity and time.

For longer distances (half marathon and more), carbohydrate loading for 24-48 hours before the event can help increase glycogen stores, thus improving the availability of fuel during the marathon. (Carbohydrate Loading:



More specifically . . .


The day before the marathon (12 – 24 hours before the race):

The pre-marathon meal is an important opportunity for a final top up of glycogen stores and to optimize hydration levels

It is important to mention that foods high in fiber like whole-grain breads and cereals, nuts, seeds, raw or dried fruits and vegetables should be avoided. “Residue” is undigested food, including fiber, that makes up stool. The goal of the diet is to have fewer, smaller bowel movements


The following fruits and vegetables are well tolerated:

  • Well-cooked fresh vegetables or canned vegetables without seeds like beets, green beans, carrots, mushrooms, spinach, squash (no seeds), and pumpkin
  • Cooked potatoes without skin
  • Tomato sauce (no seeds)
  • Ripe bananas
  • Canned or cooked fruits without seeds or skin, like applesauce or canned pears


Meal ideas:

  • Refined Pasta with skinless chicken breast + boiled carrots + 1 glass of fruit juice (without the skin)
  • Pork fillet (without the skin) + plain white rice + boiled zucchini and carrots + 1 glass of fruit juice (without the skin)
  • Tuna in water + white pitta bread + light mayonnaise + lettuce



Snacks (1-2 hours before the race):

Ideally the snack should be low in fat and fiber in order to avoid stomach discomfort. Also, the snack should contain mainly carbohydrates and a little protein. Examples include:

  • Peanut butter on bread
  • 1 piece of low fat cake
  • Banana with honey
  • Yogurt with nuts and honey

During the race

Athletes should have two main goals during exercise; (especially in long-term sports such as marathon or athletes exercising in the morning after an overnight fast where hepatic glycogen levels have dropped): They should keep themselves hydrated but also provide their body with carbohydrates to maintain blood glucose levels.



400 – 600 ml of liquids are recommended 1 hour before exercise and 150 – 350 ml every 15-20 minutes during the race (depending on the tolerance).

Of course, it is not necessary or practical to replace all sweating losses during the race, but better replenish about 150% of the loss, 4-6 hours after exercise.


Energy Drinks

Sports foods such as gel, sports bars and sports drinks are suitable and easy choices to consume during the race. Professionals or amateur athletes can benefit from the use of a sports drinks during prolonged exercise.

The energy drinks consumed should be easily digested, rich in carbohydrates but low in fat, fiber and protein as these slow down digestion.

The consumption of a sport drink with carbohydrate for half marathon or longer events should contain 30-60g carbohydrate per hour and 6-8g carbohydrate per 100 ml of water.

Some runners diversify their choice of food / beverages at various stages of the event and many use cola drinks in the later stages of the race for the added benefit of caffeine to boost performance.


And finally. . .recovery

High-intensity training sessions, races or long runs deplete glycogen stores so consuming a carbohydrate-rich meal/snack soon after finishing will help to maximise recovery. In addition, the recovery meal or snack should include ~20 – 25 g of high quality protein to aid with muscle repair. Including healthy fats will also help to reduce inflammation. Fluids (predominantly water) should be also included to re-hydrate and replace sweat losses.

Some recovery food suggestions include:

  • Tuna, avocado and salad sandwich
  • Poached eggs on toast with side of veggies
  • Yoghurt with muesli with nuts and fresh fruit



Demetra Skapoullarou

Clinical Dietitian – Nutritionist, MSc