Food integrates the set of voluntary and conscious acts that lead to the choice, preparation and ingestion of food, these facts are clearly related to the sociocultural and economic environment and determine, at least in large part, nutritional habits .
The concept of nutrition refers to the set of processes of an involuntary nature that occur after ingesting food, that is, its absorption (passage into the blood), its metabolism (chemical transformations at the cellular level) and excretion (elimination from the body. ). Adequate nutrition is one that covers:
- Energy requirements through the ingestion of adequate proportions of energy macronutrients (carbohydrates –HC-, fats and proteins).
- The needs for non-energy micronutrients (vitamins and minerals).
- Correct hydration (water consumption).
People need to eat to cover their energy needs (energy expenditure) that are directly related to the degree of physical activity. However, other factors directly influence energy expenditure.
In winter sports, the energy consumption associated with training depends fundamentally on four factors:
- The friction of the board with the snow.
- The displacement of body weight uphill and on the flat.
- The acceleration of the different segments of the organism and the center of gravity.
- Overcome air or wind resistance.
On the other hand, the relative importance of these determining factors of energy consumption during snowboarding depends in turn of the technique and type of style (halfpipe, alpine, freeride), the technical level of coordination, the type of track, the snow conditions and the speed of the race. For this reason, it is difficult to specify the energy expenditure associated with awinter sport.
In the human body, energy expenditure is directly related to the amount of muscle mass (active mass); athletes who weigh more and have a large muscle mass consume more energy at rest and during exercise than their lighter counterparts. In general, women, starting from adolescence, have a higher percentage of body fat and a lower proportion of muscle mass, so their requirements calories will be lower.
The intensity and duration of the exercise determine the priority fuel that will be used by the muscle. In general, the greater the intensity of the exercise, the greater the use of muscle and liver glycogen (a reserve form of carbohydrates) to obtain energy. To support high training intensities it is necessary to burn carbohydrates. Glycogen reserves are limited, so the longer the moderate or high intensity exercise - glycogen emptying -, the more likely we are to use reserve fats. On the contrary, when the intensity of the exercise is light, the priority fuel will be fats.
Resistance training leads to an improvement in fat utilization, using fewer carbohydrates for the same intensity of exercise. This adaptation contributes to a saving effect on glycogen reserves. On the other hand, resistance training improves the muscle's ability to store glycogen as long as the diet consumed after training provides the carbohydrates necessary for recovery.
Pregnancy and lactation constitute situations in which more energy is required for tissue growth and/or for the secretion of the mammary glands. Finally, when training in an environment with cold temperatures, the increase in body core temperature is reduced and internal heat production increases through greater use of substrates.
When tremor occurs (involuntary rhythmic contraction), it is estimated that energy expenditure increases by 2.5 times; in this situation the degree of oxidation of HC increases up to almost six times. On the other hand, in cold conditions the increase in sympathetic adrenal activation (nervous innervation of the adrenal glands) leads to an increase in adrenaline levels in the blood when exercising at low temperatures, which leads to an increase in degradation. muscle glycogen and glucose production by the liver. Therefore, the use of HC increases when training in a cold environment and it is necessary to replenish them through a diet high in HC.
