supplements

Food supplements for marathon runners and walkers

March and marathon are two disciplines made fascinating by a mix of fatigue and emotions difficult to understand by those who, at least once in their life, have not had the opportunity to practice them.

The marathon runner and the walker have particular and different nutritional needs compared to the sedentary and many other sportsmen; to satisfy them it is necessary to set, first of all, a correct and balanced food program. Only afterwards it will be possible to evaluate and possibly undertake a specific dietary plan, rationally supported by one or more food supplements.

How should the walker and marathon runner be fed?

Daily nutrition should focus, above all, on the consumption of a wide variety of foods. In fact, we know that there are no complete foods and that each of them provides different percentages of individual nutrients.

To satisfy the increased caloric needs linked to intense physical activity, it is important to have a hearty breakfast. Lunch and dinner will eventually be supported by one or two snacks, so as not to overload the digestive system during main meals. For the same reason it is a good rule not to overdo the portions, especially during the meal that precedes the training or the competition.

The Mediterranean diet is the reference model for any endurance sportsman. Although this food style gives a lot of importance to carbohydrates, we must not forget the fundamental role of fats and proteins, which must always be taken in the right proportions. Obviously it is important to obtain these nutrients from the best food sources, such as olive and seed oil, for fats, and white meat, legumes and fish, for proteins.

The rule of 5 can be particularly useful for marchers and marathon runners:

do not let more than five hours pass between meals;

consume at least five daily meals (breakfast, lunch, dinner + two snacks)

Carbohydrates and maltodextrin supplements

Carbohydrates are the main energy substrate of our body. For this reason they should provide, by themselves, about 50-60% of daily calories.

Not all carbohydrates are the same, some are quickly digested and absorbed (with a high glycemic index); others are assimilated slowly, ensuring a moderate but constant energy flow over time (low glycemic index).

Each gram of carbohydrates provides an average of 4 calories. In the athlete's liver and muscles, 250 to 450 grams of glucose are present in the form of glycogen (depending on the state of nutrition, training and body size). These deposits guarantee a reserve of 1000-1800 calories, enough to travel from 20 to 35 Km. Once this threshold is exceeded, especially if the body is not well trained to extract energy from fat and to save glycogen, it goes inexorably against a drop of the performance, which for some translates into a real crisis.

Carbohydrate based food supplements are intended to provide energy in the short, medium and long term. These products can be used:

before the effort, to increase the reserves of muscle and liver glycogen in the days preceding the competition;

during exertion, to replenish the oxidized glucose and prevent the total depletion of glycogen reserves;

after exertion, to speed up recovery by restoring glucose stocks.

Proteins and amino acids

The requirements for amino acids and proteins are also significantly higher. Runners and walkers find themselves having to face the loss, albeit modest, of those amino acids used for energy purposes during training and competitions. Physical commitment also increases protein turnover, that is protein turnover, first of all contractile, worn out and no longer efficient.

The correct distribution of food in the five daily meals ensures a constant supply of proteins, thus providing multiple benefits:

if too many proteins are taken at once (over 30-35 g), the effectiveness of the absorption processes decreases;

the stimulus to protein synthesis remains high for some tens of hours; a "constant" protein intake during this period guarantees the maximum availability of amino acids for cell regeneration processes.

Protein supplements?

The daily protein requirement of those who regularly practice basic disciplines, such as walking and marathon, is between 1.4 and 2 grams of protein per kg of body weight. If the diet includes a small protein source at each meal (dried fruit, legumes, meat, fish, cheese or eggs) normally no specific supplementation is required.

A separate discussion deserves instead the integration with single amino acids, such as the branched (BCAA) or glutamine. It is precisely the products containing these nutrients that represent the fulcrum of food supplementation for endurance athletes.

During intense and prolonged physical activity the body mainly uses these amino acids as a source of glucose and additional energy or "emergency". Glutamine is also important for strengthening the immune system and increasing resistance to infections, while an adequate intake of BCAA counteracts the perception of fatigue towards the end of prolonged activities.

As is logical to think, if the consumption of amino acids exceeds the dietary intake, the muscle weakens, gradually losing its efficiency. Precisely for this reason, although they are contained in meat or fish at a rate of about 2%, BCAA supplementation can help improve sports performance or at least accelerate recovery, removing the risk of entering overtraining (especially when associated with glutamine).

The recruitment schemes normally proposed are the following:

Branched amino acids 4-6 g / day

daily intake: immediately after the activity - anabolic phase -

or at the end of the effort and before going to sleep

or 2-3 grams 30-60 minutes before physical activity + 2-3 grams at its conclusion.

In long trials, branched amino acids can also be taken during competition (1 gram per hour)

Glutamine: 1-3 grams

60 minutes before the beginning of the effort together with carbohydrates, as well as being better absorbed in conditions of high glycemia, it satisfies the increased metabolic demands during physical exercise.

Immediately after training or in any case within thirty minutes from the end of the exercise. In this case the integration is recommended together with abundant liquids and branched amino acids, in order to favor the recovery and the cellular anabolic processes.

Fasting, possibly before going to bed, to stimulate the secretion of gh.

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