Proteins, lipids, carbohydrates and micronutrients: what are they for?This deliberately synthetic information aims to give you a clear and hierarchical vision of the major balances and nutritional priorities. The important thing is the overall understanding of the needs and the role of each family of nutrients. To function properly, that is to say, to maintain good condition and have sufficient energy, our body needs:
- Water: without water our survival is limited to a few days
- Food: without food our survival is one month maximum.
- the proteins
These are molecules composed of an assembly of amino acids linked together. There are 20 amino acids in total, 8 of which are said to be essential because they cannot be synthesized by the body and therefore need to be supplied in sufficient quantities through food. Proteins are the main constituents of all tissues in our body: skin, organs, muscles but also hormones, enzymes and antibodies of the immune system. Protein is not normally used as a direct energy source. For energy production, the body primarily uses carbohydrates and lipids. The use of proteins for production results in a loss of muscle mass, a sign of undernutrition.
What are the needs ? Contrary to popular belief, it is not necessary to overconsume proteins. Indeed, observation of average real consumption in Western countries shows a strong overconsumption of proteins: twice as much as calculated needs. It's useless, expensive, possibly harmful to health, certainly not ideal for the planet, but it amounts to saying that omnivorous athletes are rarely deficient in protein with a regular diet. The needs of an average adult (without growth, only for body maintenance) are 0.7 to 0.8 grams of protein/kg of weight/day, or 50 to 70 grams of protein (so for example 200 to 280 grams foods with 25% protein).
Protein requirements are higher for athletes because the muscles involved require more amino acids for their maintenance. Vegetarians and vegans escape this protein frenzy with much more measured intakes. If we take into account the less complete amino acid profiles of most plant proteins and the lower average digestibility of these, we can reasonably recommend a protein intake of 1 g/kg of weight per day for sedentary vegans. (non-athletes) and apply the same safety coefficient of +20/40% for the maintenance needs of vegan athletes, i.e. 1.2 to 1.4 gr/kg of weight per day (without gaining muscle mass).
Carbohydrates are all the “sugars” that are used for energy production. Before talking about nutrition, we must realize the exceptional nature of this family of nutrients without which no life on earth would have developed. Carbohydrates are quite simply the result of the transformation of solar energy into nutrients by the photosynthesis mechanism of plants, at the origin of the entire food chain. Without sun, no carbohydrates, therefore no life.
Carbohydrates are the body's preferred energy suppliers in the form of glucose . They are useful for brain function as well as for physical activities. Depending on their composition (their number of carbon atoms), we distinguish between “fast” carbohydrates (glucose and other similar forms, which enter directly into the energy production process) and “slow” carbohydrates (e.g.: starch from pasta and potatoes etc.) which can be stored (in the form of glycogen) in the liver and muscles, but which are not immediately available. They must be reduced to glucose to be used. One gram of carbohydrates provides 4 Calories: for an average energy expenditure of 2000 calories/day, if we consider that carbohydrates must cover at least 50% of these needs, we therefore need 250 grams of carbohydrates per day (1000/4). Long-term intense sporting activity (running, cycling) can represent an additional expenditure of 600 kcal/hour.
Lipids are fats and oils. Their common characteristic is to be insoluble in water. We colloquially distinguish between saturated lipids (all of whose carbon atoms are saturated with hydrogen) which are solid at room temperature, and unsaturated lipids which are liquid at room temperature (oils). Lipids are involved both in the composition of tissues, and in particular cell membranes, in the metabolism of fat-soluble vitamins (A, D, E, K) and in the supply and storage of energy: fats constitute by far the first energy store of our body (1 gram of lipids produces 9 calories). We will see in the next chapter the benefit of training to use your fats properly. As with amino acids, certain lipids are essential (must absolutely be provided through food), this is particularly the case for Omega 6 and Omega 3 fatty acids and particularly DHA and EPA (the body synthesizes a little of them, but not in sufficient quantity). If these 3 macronutrients are essential to your health, it is also important to talk about vitamins and minerals.
Vitamins and minerals
Vitamins and minerals are micronutrients that represent approximately 4% of our weight. The most important are Calcium and phosphorus (sodium, magnesium, potassium) which are involved in the composition of bones and teeth, but also in the mechanisms of energy production and muscle contraction. All minerals and vitamins have specific essential functions. The daily needs for each micronutrient are well evaluated * (by the VNR: Nutritional Reference Value). Athletic effort increases the use (and/or elimination) of most vitamins and minerals . It is therefore necessary to compensate for these losses with additional contributions to maintain the level of performance.
* Vitamin B12 and iron for vegans escape this rule because it is commonly accepted that in the absence of any consumption of animal products, daily intakes of Vitamin B12 must be 3 to 4 times higher than the NRV. The low absorption by the body of iron contained in plants (non-heme iron = non-blood iron) should also encourage vegans to take a similar margin of precaution for this mineral. (An annual blood check for these two elements is also recommended).
For further understanding:
The main mechanism of energy production: ATP and Krebs CycleIf the ATP only means a tennis association to you, take the time to read what follows. ATP also refers to the molecule (adenosine tri phosphate) which, through a mechanism known as the Krebs cycle and in the presence of a lot of oxygen, is the basis of energy production by the body. The remarkable phenomenon to keep in mind is that ATP can be obtained both from carbohydrates (the easiest solution) but also from lipids (the stock triglycerides). Our energy therefore comes from two main sources: lipids and carbohydrates. Our engine is opportunistic and can accept several types of fuel!
Limit the acidity of the body during exercisePhysical effort increases the acidity of the body, in particular through the production of the famous lactic acid. The latter is the cause of muscle burns and induces cramps and intense pain. Lactic acid is a by-product of the Krebs cycle whenever there is a slight lack of oxygen . Reducing lactic acid production and reducing overall acidity are important sub-objectives of training and sports nutrition. In terms of diet, we must recommend, in addition to good hydration:
- For a medium-term structural effect: good magnesium intake (easy for vegans: seeds, cabbage, turnips, peas, etc.), omega 3 (oils or supplements ) and group B vitamins which allow optimal use of the glucose.
- In the short term before, during, after exercise: sodium or potassium bicarbonates diluted in water are very useful to limit the increase in acidity and therefore delay the appearance of pain, cramps and facilitate recovery. (most sports drinks contain it). Do not exceed 10 grams per liter of water (1%) and test beforehand to adjust to your sensitivity (too high a dosage can be nauseating).