Food and sport:our advice

Water and Food Intake in Practice of a sport, are to be adapted according to many parameters, in particular the duration of the effort and the type of effort provided during the sporting activity.

How to stay hydrated?

During a session of physical activity, athletes must limit their water loss to 2% of their body mass to avoid the risk of dehydration. To do this, he must pay attention to:

• drink 120 ml of drink every ten minutes, without waiting for the feeling of thirst, during intense exercise. The minimum sufficient consumption during prolonged exercise under normal climatic conditions is in fact estimated at 500 ml
  per hour.
• in the event of extreme heat and prolonged and/or intense exertion, the athlete should remember
  to hydrate even more. He must anticipate his water needs because the feeling of thirst is not an accurate indicator of his real needs.

Several symptoms may raise suspicion of dehydration:

• a feeling of fatigue, heaviness in the legs, followed by shortness of breath, decreased alertness, general weakness may indicate severe dehydration.
• fever, dizziness, can be the first signs of “heat stroke”. “Heat stroke” is favored:
  • by lack of training
  • hot and especially humid weather
  • intensity and hardness of exercise
  • confinement during an indoor sports session, for example
  • fatigue
  • excess clothing worn
  • alcohol
  • certain medications

The major factor is insufficient rehydration during exercise.

If the athlete thinks he is dehydrated, then daily rehydration is done:

• during meals, take two or three glasses per meal to avoid slowing
  digestion
• between meals, in repeated amounts, up to half an hour before
  meal and from two hours after the end of a meal

Sparkling water is not recommended since you are looking for intestinal comfort.

How to get enough carbohydrate?

Carbohydrates are essential for proper muscle function during exercise. They are stored in the muscles and the liver and then released during physical effort. Carbohydrate intake is therefore important before prolonged and/or intense physical exertion. It is possible to supplement this intake with snacks or energy drinks adapted to the athlete, during the sporting event. The choice of the composition of these products varies depending on the type of sport practiced.

Carbohydrate intake represents approximately 55% of Total Energy Intake (TEI). During the training period and the day before the competition, this carbohydrate intake will be made up of 2/3 complex carbohydrates, also called “slow sugars” and 1/3 simple carbohydrates, also called “fast sugars”.

Three elements influence the distribution of carbohydrate intake and the nature of the foods to be consumed:

• training and competition periods
• the glycemic index of foods
• the amount of food consumed

The glycemic index is an indicator of the increase in blood sugar, commonly called “blood sugar level”, when you consume a food source of carbohydrates. The higher the index, the more the food eaten causes a rapid rise in blood sugar. Foods that are sources of “slow sugars” with a low glycemic index should be favored before physical exertion. The athlete will favor whole foods, without prolonged cooking, and foods in pieces rather than purees.

As far as fast sugars are concerned, two elements must be considered:

• pure glucose should be avoided in the hour preceding training
• the athlete will prefer foods that are sources of fructose, such as fresh fruit,
  because they improve endurance during intense exercise

During a training or competition that lasts more than an hour, a mixture of glucose and fructose can be interesting.

Foods too rich in fiber such as pulses are not recommended in the period preceding the practice of sport because they create digestive discomfort.

How to adapt your protein and micronutrient intake?

As part of a balanced diet of a moderately active person,
proteins cover about 15% of Total Energy Intake (TEI). Given the increase in energy requirements when playing sports, protein requirements also increase. These contributions are to be adapted to the person, the type of physical activity practiced and the frequency of training and competitions.

Certain minerals must be present in greater quantities in the athlete's diet:

• magnesium intake should be increased without being excessive.
  Indeed, excess magnesium reduces the absorption of other minerals in the intestine, and in particular calcium.
• Iron and calcium intake are important.
• the excretion of zinc, copper, iodine, due to significant sweat losses must be compensated.
• the loss of sodium can be compensated by adding 1g of table salt per liter of drinking water or by consuming a drink containing 400 mg of sodium per litre.

Vitamin intake should also be given special attention. Deficiencies decrease the athlete's performance, but unnecessary vitamin supplementation does not increase performance.
B vitamins and vitamin C should be given special attention.

Food supplements should not be consumed without the advice of a health professional (doctor, dietician, nutritionist, sports doctor, etc.).

What are the athlete's energy needs?

The athlete's energy needs vary depending on the chosen discipline. Indeed, a marathon runner does not have the same energy needs as a sprinter who provides a very intense effort in a very limited time. His energy needs change with the frequency, intensity and duration of his physical exertion. Finally, the athlete's energy needs change considerably during the year, as they are subject to their training and competition schedule.

The energy requirements of the athlete also vary according to their sex.
The needs of a woman are generally lower than those of a man practicing the same type of physical activity. They also vary depending on the height, weight and age of the person.

It is necessary for every athlete to adapt their diet to their physical activity in order to preserve their health, and to preserve their strengths and performance. He must be attentive to the quality of the food and drinks consumed, to their quantity, but also to the time
of taking the food because this last criterion influences his performance.

Each profile being very different, a health professional (sports doctor, nutritionist, dietitian, etc.) can help the athlete to precisely define his energy needs.

Source:European food information council (EUFIC).