Nutrition for a marathon – MARATHONS.FR

The marathon continues to be a legendary distance for all athletes, especially for those who are used to running occasionally in an essentially leisure environment, but not only… In fact, it is not uncommon to see runners who are used to completing races like 10 , 15 km, half marathons and constantly “mirroring” the completion of 42,195 km. The word “Marathon” is sometimes too strong to say at first glance. Increasing the distance doesn’t just mean modulating your training, but agreeing to take the food component into consideration before, during and after.

In other words, in this type of endurance running it is necessary to tame sports nutrition in an ideal and fun way, as the athlete’s body is limited to the level of energy spent during a certain time running. People who are used to doing these races and also ultras will tell you: training is good, training + nutrition is better. Have you ever seen an electric car running without “juice”? No, because it simply requires a minimum of energy. This is also true for many disciplines, needless to say.

What is good nutrition for a marathon?

Among road running and marathon enthusiasts, imbalances regularly encountered are:

  • an often “anarchic” and poorly balanced diet, including poor meal distribution and little variety of meals
  • very low food intake associated with minimal intake of lipids, minerals and vitamins
  • very low hydration and poorly distributed over time

Obviously, it is essential for the marathon runner, whether amateur or professional, that their diet is adapted to their personal parameters (age, sex, height, % body fat (BM), medical record, etc.), to their type of activity. . (sprint ≠ half distance ≠ marathon!) as well as its degree of intensity (competition/leisure) and volume, the frequency of training sessions (1 time/day, 3 times/week, etc.), competitions, as usual rhythm of life (family, professional, friends), your tastes, your habits, your nutritional education… and of course all the factors inherent to your life.

Focus on hydration and the marathon

The amount of water that tends to guarantee an optimal body water status depends strongly on the external temperature, hygrometry (the degree of humidity where the lower it is, the greater the evaporation and the more the athlete needs to hydrate), the wind (which increases the water loss), the intensity, duration of exercise and the athlete’s level of training => the sweat glands become even more developed as the athlete trains and therefore evaporation is faster and greater, reflecting the adaptation of the human body training to better regulate core temperature.

- What diet before a marathon?

When preparing for the marathon, some people look for a specific marathon diet, but this term diet is often misunderstood, here are my explanations.

Daily diet

First of all, the daily diet must be diverse and varied, balanced, based on healthy and natural products, at least from the food industry. I always remember the three vital pillars: nutrition, hydration and sleep. If you guarantee this minimum, you will already be putting many chances on your side.

The week before the race

Then, we can optimize our potential at certain key moments, such as preparing for a marathon. Before exercising, it is about optimizing hydration, maintaining energy reserves and in particular glycogenic reserves (glucose reserves) in order to promote the duration of the effort that awaits us. Thus, the modified dissociated diet a few days before departure (generally 3 to 4 days) allows to combine optimal reserves and digestibility.

Several basic parameters must be respected during this final period. In fact, for the athlete it is about targeting several essential nutritional points to achieve good performance:

  • ensure the formation of optimal energy reserves (glycogen)
  • ensure correct muscle condition and anticipate good recovery
  • limit all digestive disorders: judicious choice of foods in general and on an individual basis
  • neglected environmental conditions during exercise

The benefit of optimized glycogen stores

There is a real advantage to having high glycogen stores, especially for these prolonged efforts because these glycogen stores determine the duration for which we can maintain a high cadence. This is what we call the concept of capacity. Thus, the factors that positively influence the level of glycogen stores:

  • the initial state of the stocks in question knowing that a muscle fiber “without glycogen” will pump more “sugar”: this is the phenomenon of “supercompensation”
  • the level of training: the more trained an athlete is, the better the storage capacity (better insulin sensitivity)
  • nutrition: a diet rich in carbohydrates promotes glycogen resynthesis, especially in the first hours after exercise (8 to 12g/kg/day). Take advantage of the metabolic windows caused in the last training sessions, often qualitative (less important in intensity), to optimize your glycogen reserves

Important: good glycogen stores are positively correlated with good hydration: minimum 2 Liters. 1g of glycogen is stored with 2.7g of water.

Last meals before the marathon

Finally, the last meal is usually in the morning (between 8 and 12 hours after the previous meal), to leave in the morning (this is breakfast). During this period of fasting, muscle and liver glycogen reserves decrease significantly, the athlete’s hydration rate is lower than normal. Therefore, it is essential to provide digestible food to build up glycogen stores and drink to rehydrate the body. It must be taken 3 hours before departure and include foods with a low glycemic index. At the same time, always maintain good hydration by regularly drinking water in small quantities (150 to 200mL, the equivalent of a glass of water). There are different breakfasts such as:

  • Normal breakfast with bread, butter (etc.)
  • The sports cake, whether store-bought or specially homemade

Subsequently, a few hours before departure, hypoglycemia must be avoided and hydration maintained. In fact, hypoglycemia is a big problem during the last few hours of waiting, due to pre-competition stress related to the importance of the event. I strongly recommend waiting for drinks at this stage, adapted in quality and quantity.

- Nutrition during the marathon

During the race, the marathon runner must therefore ensure a supply of exogenous energy during the effort to:

  • maintain muscle and liver glycogen stores
  • preserve optimal hydration and minimize mineral losses
  • delay the onset of muscle and nervous fatigue
  • reduce muscle damage

Drinking an energy drink is beneficial for rehydrating and limiting the decline in “sugar” stores. A minimum of 500mL per hour must be respected, an amount to be increased ++ if the atmospheric conditions are hot, dry and “windy”. The latter should preferably be isotonic (neutral for a cold atmosphere) or hypotonic (neutral for a hot atmosphere) so that assimilation (therefore hydration) is optimized and digestive disorders are minimized.

As for the question of drinking or eating during the race, I essentially recommend having a drink for your complete macro and micronutrient intake. Solid foods (mainly energy bars) are not “vital” given the relatively short duration of the effort (less than 5 hours). An intermediate, energy gel, can be considered, but in addition to the exercise drink.

- Nutrition after a marathon

Once the effort is over, the recovery phase is a moment as important as the periods of waiting and effort, it is about “recharging” yourself quantitatively and qualitatively:

  • hydrate and remineralize the body
  • ensure the resynthesis of muscle and liver glycogen stores
  • promote muscle reconstruction
  • Eliminate waste
  • acid-base balance

The consumption of carbohydrates (glucose + fructose) after exercise is particularly important for replenishing glycogen reserves in the muscle (instead of glucose) and in the liver (instead of fructose). The same applies to protein consumption, the aim of which is to limit catabolism (“breakdown”) and promote anabolism (“building or rebuilding”) of damaged proteins (muscles in particular). This consumption should be done right after exercise and as quickly as possible. In fact, the faster this consumption, the greater the amount of resynthesis. We often speak of a “metabolic window”.

Note: to minimize acidosis, it is recommended to consume alkalizing drinks (containing bicarbonates or citrates, the latter being well tolerated digestively). When it comes to intestinal balance, I recommend taking probiotics for a few weeks to regenerate the flora.

Finally, I recommend complete and specific recovery drinks to optimize this phase of body regeneration.

- Concluding on the marathon runner’s diet

Preparing for a marathon requires the runner to follow a minimum of basic rules necessary to perform while having fun. Nutrition and hydration continue to be the two main complementary vectors for good preparation. Energy deficiency (carbohydrates and lipids), structural and physical (proteins, branched amino acids, essential fatty acids), psychological (branched amino acids, essential fatty acids) and physiological (essential fatty acids, minerals, trace elements, vitamins, probiotics, spices, plants) promote a reduction in exercise performance, recovery capacity and performance.

Always keep in mind that each athlete is unique and that the individual characteristics of each person mean that the environment (food, psychological, technical, tactical, etc.) will never be identical and therefore “what applies to one person does not apply to them”. necessarily. apply to training partner. There is no standard model for everyone.

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*Article published by Nicolas Aubineau, Sports Nutritionist and Clinical Dietitian

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