Nutrition of an athlete: rational diet. Nutrition for athletes. Principles of balanced and rational nutrition, drinking regimen, vitamin supplementation, food additives and their use. Diet and training regimens in different sports

In order for an athlete to achieve good results, he needs not only motivation, but also a high level of endurance, which directly depends on how well his nutrition is organized. This is very important, because with a weakened immune system and problems with well-being, the body is unlikely to cope with the heavy physical stress that athletes experience. Nutrition helps keep the body in good shape and achieve good results.

Healthy eating when playing sports

Organization proper diet nutrition depends on what kind of sport a person does. It is very important that the body receives a sufficient amount of vitamins and minerals, which can provide not only immune protection, but also improve the overall tone of the body. It is also necessary to take into account that physical activity requires a large amount of energy, so it is important to monitor the caloric content of the athlete’s diet.

Requirements

The following requirements are imposed on the nutrition of people involved in sports:

it must contain enough calories;
the body must receive minerals necessary for bones and muscles, as well as vitamins that support the proper functioning of the immune system;
It is recommended to take special active supplements that activate metabolic processes;
the diet is planned in such a way as to take into account the athlete’s goal - to lose or increase weight;
nutrition is organized in such a way as to reduce fat mass and increase muscle mass.

In addition, when organizing proper nutrition for athletes, it is necessary to take into account the amount of fluid consumed, in particular, clean drinking water, the lack of which can lead to dehydration, fatigue and muscle spasms. And during physical activity, the body intensively loses fluid, so it is very important to replenish these reserves.

Any diet is based on three vital elements - fats, carbohydrates and proteins, each of which performs special functions in the body. Proper nutrition for athletes, it must be planned so that these three elements satisfy the needs of the body, depending on the type of sport in which the person is engaged.

Carbohydrates

These substances constitute a group of compounds of organic origin. They are found in the cells of almost all living organisms. These compounds are necessary for normal life and are the main source of energy.

Carbohydrates are simple and complex. Complex ones are polysaccharides, which include fiber and starch, as well as some other substances. They are broken down slowly, allowing a person's blood sugar levels to change gradually. Sources of complex carbohydrates are legumes, grains, pasta made from durum wheat. This also includes fruits and vegetables, mushrooms, and berries. Let's look at the athletes' nutrition menu below.

Simple carbohydrates

Simple carbohydrates are disaccharides and monosaccharides, such as glucose and fructose. These carbohydrates quickly dissolve in water and are broken down in the body, which means they are quickly absorbed. Such substances are very useful after training because they help instantly restore energy. It is better not to consume them before exercise, as a person will quickly feel tired. What is special about athletes' nutrition?

Sources of simple carbohydrates are sugar, bananas, honey, potatoes, rice, corn, flour products, etc.

A very important point when playing sports is that before training you need to eat foods that are rich in complex carbohydrates, and after - simple ones. The total amount of these substances should be 10 grams per kilogram of weight, but the emphasis is on complex carbohydrates. It is best to consume them in the first half of the day, since in the evening, when the load is reduced, carbohydrates can be converted into fats.

Squirrels

Athletes' nutrition should include a large number of proteins, which are organic substances consisting of proteins, peptides and amino acids. These compounds play a very important role for the normal functioning of the immune and digestive systems.

The amount of protein consumed should also depend on the type of activity the athlete is engaged in. On average, it is recommended to consume 1.3 grams of protein per kilogram of weight.

Sources of proteins include foods for athletes such as chicken and turkey meat, fish, seafood, eggs, legumes, and dairy products. In addition, oatmeal and rice contain a large amount of protein. This is the main building block for muscles. They are necessary in an athlete's diet.

Fats

The next component included in the sports nutrition diet is fats. They are also naturally occurring organic compounds. Fats perform two functions - structural and organic, and the rate of their consumption per day is 0.3 -0.7 grams per kilogram of weight.

Fats come in two varieties - saturated and unsaturated, the former of which are made up of molecules filled with hydrogen. In heat they soften, and therefore they are considered harmful because they contribute to the formation of cholesterol build-ups in human blood vessels. Fats slow down metabolic processes, which complicates the process of weight loss. Foods that contain high amounts of saturated fat include coconut oil, margarine, chicken skin, pastry creams, fast food and much more.

The molecules of unsaturated fats are not completely filled with hydrogen, and their sources are products of plant origin. When heated, these fats can turn into a liquid state, so they are quickly processed by the human digestive system. Such fats are not harmful to health.

Limiting Fats

Nutritionists believe that the intake of fat in the diet of athletes should be limited. However, they are essential for life if consumed in moderation. A lack of fat leads to hormonal imbalances, impairs muscle formation, and reduces the functioning of the immune system. Unsaturated fats promote the body's absorption of vitamins, so they should be included in the diet. Such substances are found in vegetable oil, nuts, seafood and fish.

Athletes' diet

The diet of people experiencing heavy physical activity differs significantly from the diet ordinary person, so athletes must plan their menu carefully. The main aspects of this are the following:

Food must be complete, fresh and of high quality. You should only lean on those foods that benefit the body, and those that are harmful should be completely eliminated.
Amount of food in the rational diet of athletes.

Here everything should depend on the nature of physical activity experienced by the person playing sports. Some people need large amounts of food in order to gain muscle mass, others need to lose it, so nutrition should be significantly limited. That is, it is necessary to take into account your training goals and draw up a healthy diet plan. Thus, playing sports will only strengthen the body and not disrupt its functioning.

Nutritionists and doctors recommend that athletes eat small amounts but often. That is, not 3-4 times a day, but 5-6 times. This helps not to overload the body before exercise and maintain a constant energy balance in it. In addition, in this way, food is better absorbed and processed faster, without a feeling of heaviness and discomfort. Let's consider the nutritional features of athletes.

Sports nutrition options

As mentioned, nutrition options directly depend on your training regimen and type of physical activity. An athlete's daily diet is approximately 2500 calories and may look like this:

boiled eggs (2 pieces);
low-fat cottage cheese (150-200 grams);
oatmeal cooked in milk with the addition of a spoonful of olive oil;
a piece of bread;

Lunch:

fruits (for example, 1 banana and an apple);
low-fat yogurt (20 grams);
bun.

buckwheat porridge with milk;
an omelette made from two eggs;
vegetable salad (200 grams);
whole grain bread (2-3 pieces);
low-fat cheese (40-60 grams);
a glass of tea.

low-fat cottage cheese (100 grams);
buckwheat porridge with fruits or berries (200 grams);
a glass of orange juice (you can use any other juice).

fresh fruits or vegetables (300 grams);
bran bread (2-3 pieces);
a glass of kefir or milk.

Before going to bed, athletes are allowed to eat an apple or drink a glass of unsweetened tea.

Below is a diet that is designed for 3500 calories:

oatmeal (300 grams);
omelette made from 4 eggs;
toasts (2 pieces);
orange.

Lunch:

a glass of yogurt (any fat content);
bananas (2 pieces);
nuts (100 grams).

boiled beef (300 grams);
boiled potatoes (3-4 pieces);
vegetable salad (200 grams);
juice or tea.

boiled rice (200 - 250 grams);
fruit salad (150 grams);
a glass of milk.

boiled fish (250 grams);
potatoes (4 pieces);
salad made from grated carrots with the addition of vegetable oil (130 grams);
tea or juice.

Shortly before bed, you can eat a bowl of oatmeal or drink a glass of milk.

Probably no nutritionist has yet compiled a diet that would suit every athlete. This is due to the fact that each athlete needs a unique nutrition program that is suitable for him, depending on what type of load he is engaged in, what weight category he belongs to and what goals he pursues while playing sports. However, there is a list general recommendations, which are suitable for everyone without exception, they will help you keep yourself in good shape and not harm your own body.

The food is varied and of high quality. Food products for athletes must be compatible, since the absorption of some of them together is impossible.
It is necessary to prepare food so that it is healthy. The fat content of the prepared dish depends on this, which should not exceed acceptable standards.
Fractional meals. You can divide your diet into 6-7 meals, which will allow it to be maximally absorbed and beneficial.
The last meal should be no more than two hours before bedtime, otherwise fats and carbohydrates will turn into unwanted deposits on the body.
You should only eat fresh foods that are prepared before eating. Accordingly, it is necessary to exclude fast food and various types of semi-finished products from the diet.

We looked at nutrition for athletes for every day.

The basis on which the entire system of using various substances that stimulate performance, recovery and adaptive reactions is built is rational nutrition for an athlete.

Nutrition largely determines the level of performance of athletes, the effectiveness of recovery and adaptation reactions stimulated by training and competitive loads. Nutritional needs depend on the age of the athlete. The period of intensive growth (men 12-22 years, women 11-19 years) is associated with an increased need for food products.

Nutrition for representatives of different sports

Naturally, the problem of nutrition for athletes cannot be reduced to simply replenishing energy expenditure, although this indicator is an important factor in rational nutrition: depending on the specifics of the sport, the volume and nature of the load, and individual characteristics, high-class athletes should consume 2-3 times more food with high energy value compared to people who do not exercise.

For example, if the normal life activity of 19-25 year old men requires an average of 11304-12142 kJ (2700-2900 kcal), and women - 8374-8778 kJ (2000-2100 kcal), then for athletes these values can reach 25080-29260 kJ (6000-7000 kcal) and 20900-25080 kJ (5000-6000 kcal).

Training and competitive activities of representatives of various sports are associated with different energy expenditures. For example, energy consumption among weightlifters can reach 16748-18840 kJ (4000-4500 kcal), swimmers - 20900-22993 kJ (5000-5500 kcal), athletes specializing in various sports games, - 18840-20900 kD f (4500-5000 kcal). The highest values were recorded for road cyclists on mountain routes, triathletes - up to 25080-29260 kD f (6000-7000 kcal). A record figure of 35,433 kJ (over 7,700 kcal) was recorded in cycling during the Tour de France.

The athlete’s diet must meet energy needs, be varied, which allows the body to be provided with minerals and vitamins, and to ensure the consumption of the required amount of fluid sufficient to prevent dehydration of the body.

Ratio of carbohydrates, fats and proteins

It is equally important to provide the required amount and, most importantly, the optimal ratio of carbohydrates, proteins and fats. Carbohydrates are designed to provide the athlete’s body with the necessary amount of energy. The main role of proteins is to ensure the regeneration of tissues worn out during training and competitive activities, adaptive rearrangements of muscle tissue, the formation of hemoglobin, enzymes and many hormones. Fats take part in the energy supply of long-term muscle activity. However, their consumption should be limited, which largely eliminates the problem of maintaining optimal weight and promotes carbon consumption.

The ratio of carbohydrates, fats and proteins in an athlete’s diet is determined by the specifics of the sport. Athletes specializing in long-distance running, cross-country skiing, cycling (road), triathlon, i.e. in sports that require endurance for long-term work, must consume large amounts of carbohydrates in their diet, which will compensate for energy costs. Hammer throwers, shot putters, weightlifters and athletes specializing in other sports and speed-strength disciplines should use increased amounts of protein in their diet.

The typical diet of people living in developed countries contains excess amounts of fat. The recommendations of nutritionists provide for the existing correction of the combination of carbohydrates, proteins and fats, which will ensure the prevention of excess weight and the development of negative processes in the body that can lead to serious diseases. For athletes, these recommendations should be further adjusted.

For example, for athletes who train intensively in endurance sports, this ratio should include a significant increase in the proportion of carbohydrates and be 70:10:20. And in the composition of carbohydrates, a rational ratio between complex (starches) and simple (sugars) carbohydrates should be ensured, since it is known that in this case glycogen reserves in the body are more effectively replenished. Not less than 10% energy value food must be obtained in the form of simple sugars.

Fat ratio

The ratio of saturated (animal origin) and unsaturated (vegetable origin) fats is also important. With the maximum amount of fat in the diet of athletes specializing in sports not related to endurance and duration of work, about 20-30%, the amount of saturated fat should not exceed 10%.

Particular importance should be attached to a balanced and varied diet, which can be ensured by implementing the recommendations contained in the so-called food pyramid, which underlies healthy eating. A rational diet for athletes specializing in any sport should include at least a minimum amount of products belonging to each group. An increase in the number of products in the diet belonging to a particular group should be determined by energy needs, the specifics of the sport, the direction and magnitude of training and competitive loads.

Meals throughout the day

The optimal distribution of food consumed throughout the day is also important. For example, the optimal diet of an athlete, designed to consume 5500 kcal with 5 meals a day, is as follows: breakfast - 1200 kcal, second breakfast - 900, lunch - 1500, dinner - 1100, snacks, drinks - 800 kcal.

Considering the nutrition of athletes as a restorative and adaptive process in its essence, experts pay great attention to the appropriate distribution of food load throughout the day, its relationship with training and competitive loads, and ensuring the rapid absorption of food intake. Under conditions of high training and competitive loads, the most effective is multiple meals (3-4 main and 2-3 additional servings) during the day. It is important to pay attention to the fact that the bulk of food is taken in the daytime and no later than 3-4 hours before bedtime.

Material taken from the book by V.N. Platonov. “System of training athletes in Olympic sports”

For athletes, it has its own characteristics, which are caused by significant physical activity and high mental stress during sports, which requires the use of a set of means that increase endurance and performance. And rational nutrition plays an important role here.

Those who play sports should receive 4200 - 5500 kcal per day during systematic intense training with food. The Institute of Nutrition of the Russian Academy of Medical Sciences determined the daily energy consumption during intensive sports: for women 3000 - 6000 kcal, for men - 3500 - 6500 kcal. If there are exceptional cases, for example, participation in marathon running or cycling, the daily consumption may increase to 7000 - 8000 kcal.

Athletes' diet should be enriched with and, since the body’s need for them increases with intense muscular work.

Designate three types of nutrition for athletes:

Nutrition during normal training. Refers to the main type of nutrition and includes foods that provide the body with carbohydrates and proteins. We recommend eating veal, beef, pork, lean lamb, rabbit, and chicken. It is advisable to include fresh fruits and vegetables in the diet every day, which should provide at least 15 - 20% of daily energy.
Nutrition during intense training sessions and competitions. During this period, it is worth limiting the consumption of smoked and fatty meats, fried foods, sauerkraut, legumes, etc.
Nutrition during long-term sports competitions (at a distance). With this type of nutrition, it is necessary to take sugar and glucose in combination with other nutrients or in pure form; in addition, consume chocolate, especially special samples in which sugar is replaced with glucose. During periods of high stress, this provides the athlete’s body with easily and quickly digestible substances that are included in the metabolism without the strain of the digestive system. In addition, it is useful to consume glucose and sugar after the end of the competition in order to restore the performance of the heart muscle and prevent fat deposits in the liver.

The organization of an athlete’s diet is determined by the type of physical activity.

Nutrition for aerobic training

If the loads are predominantly aerobic in nature and their duration is up to 1.5 hours, then a diet with a proportional ratio of carbohydrates, fats and proteins would be advisable.

If the duration of the workout is two to two and a half hours, then two to three days before it you should switch to a carbohydrate diet, this will create the glycogen reserves in the muscles necessary for this activity.

If the duration of aerobic training is more than 3 hours, then you should first reduce some of these reserves in the muscles through a protein-fat diet, which is carried out three days before training sessions. And then you need to increase these reserves with a carbohydrate diet for two to three days.

Nutrition for anaerobic training

During anaerobic training (speed-strength exercise), a physiologically mixed diet is advisable for the athlete in order to create sufficient glycogen reserves. Such loads cause increased consumption.

During competitions, anaerobic loads are performed to a lesser extent than during training; accordingly, relatively small glycogen reserves are required (0.5 - 1%), this can be achieved through a protein-fat diet, which is prescribed two to three days before the start of the competition.

If competitions in team sports are expected, glycogen reserves in skeletal muscles should not be reduced, since the loads are predominantly anaerobic in nature and, as a rule, are long-lasting.

Preferably, a carbohydrate or protein-fat diet can be used for two to three days and no more, since metabolic disorders may develop.

Before starting long-term training or competitions, it is reasonable to take a glucose solution with the addition of lemon. Glucose helps improve the absorption of water in the stomach. When using such solutions at a distance, it is necessary to take into account individual tolerance (10 - 40%), since taking it in high concentrations retains liquid in the stomach, causing some discomfort.

Athlete's diet

Diet for an athlete plays a big role. On days when training is combined with work, it is based on general physiological principles; a 15-20 minute interval is observed between the end of training and food intake. You can’t start training on an empty stomach, but you shouldn’t eat food immediately before. sports activities also harmful.

During training camps, four meals a day are recommended. If the training takes place in the first half of the day, then breakfast accounts for 30 - 35% of the daily energy value of the diet, lunch - 35 - 40%, afternoon snack - 5%, dinner - 25 - 30%.

As a rule, athletes begin their morning training sessions one and a half to two hours after breakfast. Therefore, if breakfast was plentiful and dense, a long period is required - 3 - 4 hours, the functional state of the digestive system organs is disrupted, and physical performance decreases.

This is explained by physiological processes: the distribution of blood between the digestive organs, where the process of digestion and assimilation takes place, and the skeletal muscles, which perform significant physical work. On the one hand, physical work inhibits the digestive process, on the other hand, the digestive process helps to reduce the activity of the sympathetic center of the ANS (vegetative nervous system), the activity of which largely ensures the effective functioning of muscles.

If the workout falls in the second half of the day, then the percentage changes: 35 - 40% for breakfast, 30 - 35% for lunch, 5% for afternoon snack, 25 - 30% for dinner.

The Institute of Nutrition of the Russian Academy of Medical Sciences recommends five meals a day with the inclusion of restorative agents (before and after training) with the energy value of each meal up to 10% of daily ration, the distribution of the diet is as follows - 25% for breakfast, 35% for lunch, 20% for dinner.

In any case, the time between meals should be no more than five hours, and on the day of the competition you cannot eat later than three and a half hours before the start.

The time interval between training sessions and the next meal should reach thirty to forty minutes in order for circulatory function to be restored after intense exercise. physical activity, and there was a redistribution of blood from the skeletal muscles involved in the work to the digestive organs.

Thus, diet for an athlete has its own characteristics and, taking them into account, practical recommendations for action are offered.

Pshendin Anatoly Ivanovich
Food, nutrition is the basis of life

Food is the source of life and pleasure. As I.P. Pavlov noted, food personifies the life process in its entirety and represents that ancient connection that connects all living things, including humans, with the surrounding nature. By receiving food, a person not only satisfies the feeling of hunger, but also receives pleasure.

The term “nutrition” has a broad meaning: it denotes the entire sum of biological phenomena (the intake and transformation of nutrients in the body) that underlie the provision of energy and structural substances to any physiological function of the body. The problem of nutrition is currently one of the main economic and social problems facing humanity.

The science of nutrition examines many issues, of which the following are considered paramount:

what chemicals and in what quantities must be supplied to the body with food for its growth, reproduction and other vital functions;

what consequences does the absence or, on the contrary, excess of nutrients from food lead to?

what is the specific biological role of each nutrient;

what products and in what quantities are required to satisfy the body's nutritional needs.

One of the main modern concepts nutrition is a theory of rational balanced nutrition. This theory is based on the idea of the need not only to adequately supply the body with energy, but also to maintain the proportions between basic nutrients and other important nutritional elements to ensure its normal functioning. A key role in nutrition belongs to those substances that cannot be synthesized in the body from other components. These include inorganic ions and a number of organic compounds. About 24 organic compounds are essential components of the diet. These substances are called essential nutritional factors.

Human nutrition must be rational, that is, it must satisfy the energy, plastic and other needs of the body, while ensuring the necessary level of metabolism. Violation of human health and performance can be caused not only by a lack of individual essential factors, but also by their excess.

Acquaintance with the doctrine of rational nutrition should begin with an understanding of the biological functions of the main nutrients in the body.

Proteins and protein products

Proteins (proteins, from the Greek protos - first) occupy the most important place in a living organism, both in terms of content in the cell (at least 45% of dry mass) and in importance in vital processes. Proteins account for 17% of the total mass of a “standard person” (26-year-old man, weight 65 kg). Protein is an essential part of food and the basis of life.

Proteins perform important and diverse functions. Enzyme proteins, of which there are more than a thousand, play an exceptional role in the body. They accelerate biochemical reactions in the body by millions and even billions of times.

Hormone proteins, such as insulin, also have high biological activity. It is known that one gram of insulin is enough to reduce blood sugar in 125,000 rabbits.

Proteins play a structural role, participating in the construction of membranes, contractile elements of muscles, connective and bone tissue. The transport function of proteins ensures the transfer of various substances to tissues (oxygen, lipids, etc.) with the blood. The protective function of proteins of a special type (immunoglobulins) provides immunity - a way to protect the internal constancy of the body from living bodies and substances that carry signs of genetically foreign information.

If food is low in carbohydrates and fats, especially during fasting, proteins also serve as reserve nutrients and sources of energy.

Insufficiency of protein in food products is a determining factor in the development of severe health disorders: nutritional dystrophy, growth retardation, weight loss, decreased body defenses, suppression of the endocrine glands, fatty infiltration of the liver, etc. The average daily requirement for protein for the regions of our country is determined in quantity 80-100 g. Proteins consist of 20 amino acids. L-amino acids determine the nutritional and biological value of proteins.

Some amino acids cannot be synthesized in the body. They are called irreplaceable. Such amino acids must enter the body as part of food. The balance of essential amino acids is one of the main requirements for the protein component of food products.

For an adult, the following formula for the balance of essential amino acids can be adopted (number of grams per day): tryptophan - 1, leucine - 4-6, isoleucine - 3-4, threonine - 2-3, lysine - 3-5, methionine - 2- 4, phenylalanine - 2-4, valine - 3-4 (see Table 1).

The biological value of an individual protein is understood as its relative nutritional value compared to a standard protein.

The closer the amino acid composition of food proteins is to the composition of the protein in our body, the more valuable it is. From this point of view, the most valuable sources of protein are eggs, milk, and meat. Plant proteins often lack essential amino acids such as lysine, methionine and tryptophan. To obtain the optimal ratio of amino acids, it is necessary to strive for a successful combination of animal and plant products. For example: grain products and milk, meat, eggs, fish; potatoes and milk, dairy products; corn and milk, peanuts, rice; legumes and milk, rye; wheat and peanuts, yeast.

The body's need for protein depends on a number of reasons: with age it decreases, in stressful situations, regardless of age, it increases.

Two- and three-time daily training of athletes, high nervous tension during competitions, decreased activity of the immune system, unfavorable weather conditions during competitions - all this intensifies protein metabolism. At the same time, the athletes’ body’s need for protein can double the normal level.

Proteins (amino acids) are the most important component of food. It is important to know the main protein foods and their nutritional value.

Meat is a highly valuable food product, a rich source of complete animal proteins, containing all essential amino acids in significant quantities and in the most favorable ratios.

The biological value of meat is mainly judged by the quantity and quality of the proteins it contains. The richest in proteins (up to 20%) are beef, pork, as well as rabbit and poultry meat.

However, all types of meat contain a certain amount of connective tissue (tendons, membranes, joint capsules, etc.). Connective tissue proteins are represented mainly by collagen and elastin, the biological value of which is low due to an incomplete and insufficient set of essential amino acids (tryptophan is practically absent, cystine is in small quantities). On the other hand, they contain a lot of non-essential amino acid - hydroxyproline. Connective tissue proteins are poorly absorbed by the body. The average content of connective tissue proteins in meat is 12-15% of the total protein. This largely depends on the type of meat and, most importantly, from what part of the carcass it was taken. Thus, the muscles of the chest, abdominal part, neck, and limbs contain a significant amount of connective tissue, are characterized by great rigidity, and require longer cooking (prolonged cooking in order to convert collagen into the soluble compound glutin).

The fat content of meat varies widely (from 2 to 50%) and depends on the type of meat, the age of the animal or bird, and the part of the carcass. Meat fats contain mainly saturated fatty acids, which determines their high melting point and more difficult absorption by the body. Of all animal fats, pork fat has the best biological properties, since it contains a certain amount of polyunsaturated fatty acids (linoleic, linolenic and arachidonic).

The total amount of minerals in meat is about 1%. Meat contains relatively a lot of potassium (up to 350 mg per 100 g), phosphorus (about 200 mg per 100 g), magnesium (25-27 mg per 100 g). Many types of meat are rich in highly absorbable iron (up to 3 mg per 100 g). There is especially a lot of iron in the liver (per 100 g beef liver about 7 mg, in pork - over 20 mg). Iron in meat is in a hemoglobin form that is easily absorbed by the body, which is absorbed by 30%, while iron in vegetables and fruits is absorbed by only 10%. Other minerals contained in meat are also well absorbed, which determines the high biological value of this product. Meat is the most important source of B vitamins. Veal and pork meat are especially rich in them.

Of great nutritional importance are the extractive substances contained in meat (creatine, carnosine, purine bases, etc.), which, when cooking meat, turn into a decoction and give a specific taste to the broth. These substances are strong stimulants of gastric secretion, which is why strong meat broths are used in the diet of people with reduced appetite.

Beef contains the most complete proteins, which include almost all the essential and non-essential amino acids necessary for the body.

Veal, which is more tender than beef, contains more complete proteins and is easier to digest by the body. Veal of the 1st and 2nd categories contains about 20% protein and 1-2% fat.

Pork contains less connective tissue than beef, which makes it more tender and delicate in taste. By variety, pork is divided into bacon, meat and fatty; the latter contains up to 50% fat and only 12% protein. In the nutrition of athletes, it is better to use meat pork, containing on average 14% protein and 33% fat. It is important to note that pork tenderloin contains 19% protein and 7% fat, and brisket contains 8% and 63%, respectively.

Compared to beef, lamb contains more connective tissue, so it is tougher. In terms of the chemical composition, category 2 lamb roughly corresponds to beef of the same category. However, lamb contains slightly less potassium, phosphorus and iron salts.

Horsemeat of the 2nd category is rich in complete proteins (21%), potassium and iron salts, while it contains relatively little fat (4%). In terms of biological value, horse meat proteins are not inferior to beef proteins.

Rabbit meat is an excellent dietary product, characterized by a high content of protein (21%), iron, and B vitamins. It contains sufficient quantities of potassium, phosphorus, magnesium and other minerals.

By-products are of particular value for the nutrition of athletes. Many of them are characterized by a high content of minerals, especially iron and vitamins, and are therefore recommended for people with underweight and anemia. The liver is especially rich in iron, vitamins A and B; Unlike other meat products, it contains a large amount of ascorbic acid (vitamin C). Language is dietary product. It contains little connective tissue, which ensures its high digestibility. The heart is rich in mineral salts, including iron, has a low percentage of fat, and a sufficient amount of protein. Brains contain less protein (12%) and quite a lot of fat (8.6%), but they contain valuable compounds rich in phosphorus and essential unsaturated fatty acids, and this significantly increases their biological value. The lung is especially rich in iron (10%), but otherwise the nutritional value of this product is low.

Sausages are mainly prepared from beef and pork. Many of them are high-fat foods; the amount of fat in them ranges from 13.5% (dietary sausage) to 40% or more (various types of smoked and semi-smoked sausages). The latter, especially those with a high fat content, are not recommended for use in sports nutrition. Sausages and small sausages differ from sausages in that they have a more delicate consistency and lack lard. To prepare sausages and sausages of the highest grade, meat (beef, pork) of young animals is used, which is easily digested and assimilated, therefore this type of meat product is preferable to sausages.

Along with a wide range of sausage products, the industry produces pork meat products (ham, brisket, loin, ham, etc.). They are distinguished, as a rule, by a very high fat content (up to 50-60%) and therefore are not recommended for systematic consumption.

Canned meat, especially pork, is also characterized by a high fat content. Their nutritional and biological value is lower than dishes made from fresh meat, since in the process of preparing canned food such technological methods as long-term cooking at high temperatures, autoclaving, etc. are often used. Many canned foods are prepared from lower grades of meat, therefore they often contain a significant quantity of connective tissue fibers. There are fewer vitamins in canned meat than in fresh foods. However, in the absence of natural meat, canned food can be used in food, mainly for preparing first and second courses. When consuming canned meat, you must pay special attention to the timing of their production and do not use products that have expired.

Meat from chickens and broiler chickens contains more complete and better digestible proteins than beef. Squirrels chicken meat have an optimal set of essential amino acids. The amount of fat in the meat of chickens and chickens is quite large (on average 16-18%), but this fat is easily absorbed by the body, since it includes a certain amount of unsaturated fatty acids and has a relatively low melting point. Chicken meat contains the necessary set of minerals and vitamins. Extractive substances give it a pleasant smell and taste.

Fish, along with meat, is one of the best sources of high-quality protein. Fish proteins contain all the essential amino acids necessary for the body. Unlike meat, fish proteins contain large quantities of such an important essential amino acid as methionine. The advantage of fish proteins is their low content of connective tissue formations. In addition, the connective tissue proteins of fish are represented mainly by collagen, which more easily passes into a soluble form - gelatin (glutin). Thanks to this, the fish quickly boils, its tissues become loose, easily susceptible to the action of digestive juices, which ensures more complete absorption of nutrients. Fish proteins are digestible by 93-98%, while meat proteins are digestible by 87-89%.

Fish fat is distinguished by a significant content of polyunsaturated fatty acids, the total amount of which in most fish species ranges from 1 to 5%, while beef and lamb have these acids in small quantities - from 0.2 to 0.5%. Due to the high content of polyunsaturated fatty acids, fish oil is easily absorbed by the body. The composition of fat also includes various fat-like substances (phospholipids, lecithin), which have high physiological activity. Fish fat is found mainly in the liver (in fish belonging to the cod species) and in the subcutaneous tissue (in herring and salmon). It is important to know that fish oil oxidizes quickly, and its nutritional value decreases.

The meat of almost all types of fish is rich in mineral elements: potassium, magnesium and especially phosphorus, the amount of which reaches 400 mg per 100 g (flounder). Selected species contain sufficient amounts of calcium and iron. Fish is an important source of B vitamins; the liver of many fish has a high content of vitamins A, D, E. Sea fish is rich in rare elements such as iodine and fluorine.

Fish roe is a valuable food product with a high content of protein (up to 30% or more) and fat (about 15%). Caviar is rich in phosphorus and potassium, water- and fat-soluble vitamins. Fish milk is rich in essential amino acids and has low fat content.

Salted and smoked fish products are less valuable products. As a rule, the proteins in these products, due to the nature of their processing, are much worse digested and absorbed. Many smoked and salted fish contain large amounts of fat, excess sodium, and are poor in vitamins. Herring and other fish gastronomic products can be used as snacks to stimulate the appetite. They should be given before the main meal and in small quantities.

Canned fish is not recommended for widespread use in the diet. In the process of preparing canned food, many valuable qualities of fish are lost. Long-term storage of the product also leads to this. Some types of canned fish can be used, like fish gastronomy, as snacks and delicacies (herring, sprat, sprats, caviar).

Egg products are complete sources of all essential nutrients necessary for the normal functioning of the human body. Only chicken eggs are allowed to be used in food, since waterfowl eggs (geese, ducks) are often contaminated with pathogens of severe intestinal infections (salmonellosis, etc.).

A chicken egg, compared to other animal products, contains the most complete protein, almost completely absorbed by the body. Egg white contains all the essential amino acids in the most optimal proportions. Egg fat consists of fatty acids, mainly polyunsaturated, and phospholipids, mainly lecithin (1/3 of the total fat), which has a beneficial effect on cholesterol metabolism. Eggs are rich in minerals, especially phosphorus, sulfur, iron, and zinc. They have a sufficient amount of fat-soluble vitamins (vitamin A is the same as in butter, and vitamin D is 3.5 times more). In addition, eggs have a fairly high content of B vitamins.

Composition of protein and yolk chicken egg not the same. Egg white consists almost entirely of substances that are easily digestible after heat cooking. Raw egg white is poorly digestible, as it contains some compounds that inhibit the action of digestive enzymes (ovomucoid, avidin). With short cooking, these substances are destroyed, and the egg white is absorbed almost completely (98%). During prolonged cooking or frying, the digestibility of protein decreases somewhat due to its denaturation.

The yolk of an egg contains more than 30% fat, which is in the form of a thin emulsion and is therefore easily digested and absorbed by the body. Almost all the minerals and vitamins of a chicken egg are concentrated in the yolk, mainly in an easily digestible form. Heat treatment of eggs practically does not reduce the nutritional value of the product, since an egg boiled in the shell retains all nutrients unchanged.

Lipids (from the Greek lipos - fat) include a large group of organic substances contained in living cells with different chemical structures and some general physicochemical properties. Such general properties of lipids are their insolubility in water (hydrophobicity) and solubility in non-polar solvents: acetone, alcohols, benzene, chloroform, etc.

All lipids can be divided into the following classes: neutral fats - triglycerides, phospholipids, sphingolipids, glycolipids, sterols, waxes. Lipids are part of human, animal and plant tissues. Lipids are found in large quantities in the brain and spinal cord, liver, heart and other organs. Their concentration in nervous tissue reaches 25%, and in cellular and subcellular membranes - 40%. Lipids enter the body with products of animal or plant origin.

Animal fats and vegetable oils are like a concentrated energy and construction reserve of the body. These are water-insoluble substances of biological origin, consisting almost exclusively of triglycerides of fatty acids.

Triglycerides of adipose tissue and liver, if necessary, are easily mobilized, converted into other compounds or become sources of energy. Biologically, triglycerides are very important for the body as reserve substances, since per unit volume they contain twice as much energy as carbohydrates.

Fats are an essential component of nutrition. A sharp restriction of the intake of fats from food can lead to many adverse degenerative phenomena in tissues (dystrophy, weakening of the body’s immunological reactivity, etc.). So-called fat-soluble vitamins can accumulate in adipose tissue.

The biological value of fats is largely determined by the presence of essential components in them - polyunsaturated fatty acids, which, like amino acids and vitamins, cannot be synthesized in the body and must be supplied with food. Food sources of polyunsaturated fatty acids are primarily vegetable oils. It is generally accepted that 25-30 g of vegetable oil provides a person’s daily need for polyunsaturated fatty acids.

In food products, fats are accompanied by other substances belonging to the class of lipids. Among them, phospholipids are of particular importance. The biological role of phospholipids in the body is significant and diverse. As an indispensable component of biological membranes, phospholipids take part in their barrier, transport, receptor functions, in the compartmentalization of the cell (dividing its internal space into cellular organelles, “cisterns,” compartments), etc. These membrane functions are currently considered to be the most important regulatory mechanisms cell vital activity. The presence of phospholipids in membranes is also necessary for the functioning of membrane-bound enzyme systems. About 25 subclasses of phospholipids are known. Of these, lecithin, which has important biological properties, is most widely represented in food products.

During sports training, the need for lipids increases, especially polyunsaturated fatty acids, phospholipids and steroids. During periods of intense endurance training or competition (for example, a multi-day cycling race), it becomes difficult to regularly replenish daily energy expenditure. It is achieved by increasing dietary intake of lipids and components that stimulate their metabolism, so that an adequate diet becomes especially important. An adult's need for fat is 80-100 g per day, including vegetable oil - 25-30 g, polyunsaturated fatty acids - 3-6 g, phospholipids - 5 g.

Food products, animal and plant, contain various sterols. The most important animal sterol is cholesterol. In plant products, the most famous is B-sitosterol (most of all in vegetable oils), which normalizes cholesterol metabolism. It forms insoluble complexes with cholesterol. These complexes prevent the absorption of cholesterol into gastrointestinal tract and thereby reduce its content in the blood.

Cholesterol - normal structural component all cells and tissues involved in the exchange of bile acids, a number of hormones: androgens and estrogens, vitamin D (part of which is formed in the skin under the influence of ultraviolet rays from cholesterol). The main part of cholesterol (about 70-80%) in the body is formed in the liver, as well as in other tissues from fatty acids, mainly saturated, and carbohydrates (more precisely, from their breakdown product - acetic acid). A person gets some of his cholesterol from food. The most cholesterol is found in foods such as eggs (0.57%), cheeses (0.28-1.61%), butter(0.17-0.21%), in by-products - liver (0.13-0.27%), kidneys (0.2-0.3%), heart (0.12-0.14%). On average, meat contains 0.06-0.1%, and fish - up to 0.3% cholesterol.

During thermal cooking, cholesterol is relatively stable: about 20% of the original amount is lost. However, completely eliminating cholesterol-containing foods from your diet is unwise. As already mentioned, its main amount is formed in the body, mainly in the liver, from other food components. A typical daily diet should contain on average 500 mg of cholesterol; in case of contraindications, its content can be reduced to 300 mg.

Carbohydrates and the concept of the glycemic index

Carbohydrates constitute one of the main classes of natural substances in animal and plant organisms. Their general biological significance lies primarily in the fact that all organic substances ultimately originate from carbohydrates formed during the process of photosynthesis. According to modern scientific ideas, there are more carbohydrates in the biosphere than all other organic compounds combined. Carbohydrates make up the bulk of the human diet - 400-500 g per day. In the process of carbohydrate catabolism, the bulk of energy for life is released. Carbohydrates accumulated in the liver and muscles have a limited energy reserve.

About half of the daily energy value of the diet is provided by carbohydrates. Complex carbohydrates (polysaccharides), such as glycoproteins, glycolipids and acidic mucopolysaccharides, also have structural functions.

Carbohydrates also perform a number of specialized functions in the body. Thus, blood heteropolysaccharides determine the specificity of blood groups, and heparin, contained in the extracellular substance of some tissues (liver, lungs, arterial walls), prevents blood clotting in blood vessels.

Carbohydrates are divided into three main classes: monosaccharides, oligosaccharides, and polysaccharides. Among the monosaccharides, the most important in nutrition are glucose and fructose; among oligosaccharides - sucrose; Among the polysaccharides are starch and glycogen.

Glucose is the most common monosaccharide, found in significant quantities in various fruits and berries. Polysaccharides - glycogen and starch - are built from glucose residues. It is also contained in the molecule of sucrose and other disaccharides. Glucose is used in the body as an essential energy supplier to power the brain, skeletal muscles, heart and other tissues. In plant foods, glucose is often accompanied by fructose. It is absorbed more slowly in the intestines and disappears from the blood faster than glucose.

An important carbohydrate food product is sucrose, the content of which in granulated sugar reaches 99.75%. The main role in supplying the body with carbohydrates is played by starch, the sources of which are cereals, potatoes, baked goods, etc. The main amount of digestible carbohydrates enters the body in the form of starch.

Ultimately, almost all carbohydrates in food are converted into glucose and in this form enter the blood from the intestines. However, the rate of transformation and appearance of glucose in the blood from different products is different. The mechanism of these biological processes is reflected in the concept of “glycemic index” (GI), which reflects the rate of conversion of food carbohydrates (starch, glycogen, sucrose, lactose, fructose, etc.) into blood glucose. In table 2-5 provides information on GI for food groups. Correctly using this information, you can effectively control carbohydrate metabolism in the body.

It is known that the level of glucose (sugar) in the blood is regulated within normal limits (80-120 mg per 100 ml of blood) with the help of hormones: insulin, which reduces this level to normal, and glucagon, which increases it to normal. An increase in blood glucose levels after a meal increases the level of insulin in the blood.

Insulin is an anabolic hormone; it affects the membranes of cells of different organs so that the permeability of these membranes increases and the flow of glucose into the cells increases sharply. This is a normal mechanism for feeding cells. In cases of overweight (obesity), this process can be controlled by using foods with low or medium GI, and vice versa, with intense training - with high GI.

The body's need for carbohydrates depends on the level of energy consumption. As the intensity and severity of physical labor increases, the need for carbohydrates increases. Athletes have a higher need for carbohydrates than people engaged in light, moderate, and even heavy physical labor. With high intensity and volume of training and competitive loads, the need for carbohydrates in athletes can increase to 800 g per day or more.

Alimentary fiber

Dietary fiber is part of the plant material of food. These include complex plant carbohydrates: cellulose, hemicellulose, pectin and lignin. Dietary fiber is not digested in the gastrointestinal tract. Some of them are subsequently broken down during transit in the intestine, mainly by colon bacteria.

Dietary fiber has a number of properties that allow it to actively influence metabolism. They can:

bind water, which leads to their swelling;

absorb toxic substances and remove them from the body;

bind bile acids, adsorb sterols and reduce cholesterol levels;

increase the irritating effect of food, which leads to stimulation of intestinal motility and faster transit of food;

normalize the beneficial intestinal microflora, which leads to the breakdown of some dietary fiber.

In terms of the amount of dietary fiber, rye and wheat bran come first, followed by vegetables and Rye bread, strawberries, raspberries, rowan, avocado, kiwi.

There are certain differences in the ability to bind water among dietary fibers of different origins. Thus, dietary fiber from vegetables has the greatest ability to swell, while fiber from cereals retains water in much smaller quantities.

Foods rich in fiber cause mechanical irritation in the intestines, which increases peristalsis and speeds up the movement of food. In addition, dietary fiber increases the volume and weight of feces.

Thus, dietary fiber is not ballast substances, they actively participate in the metabolic processes of the gastrointestinal tract and are necessary for the normal functioning of the human body. However, we must remember that dietary fiber, if in excess, binds and removes from the body not only toxins, but also some of the beneficial components of food.

The daily requirement for dietary fiber for an adult is 25-30 g. This need can be met primarily by including bread, vegetables and fruits in the diet. When increasing your dietary fiber intake, keep in mind that such foods require large amounts of liquid. If you don't have enough fluid, a condition called indigestion can occur.

A wide variety of dietary fibers are available in their pure form: microcrystalline cellulose, pectins, glucomannans, etc. It is important to understand that their use as dietary supplements results in the consumption of additional amounts of water.

Vitamins

Vitamins are a group of low molecular weight essential food factors that have pronounced biological activity, are contained in food in small quantities and cannot be synthesized in the human body. The role of vitamins is to provide a number of catalytic reactions, during which many of them participate in the formation of enzyme components (coenzymes). The number of known vitamins that are directly important for nutrition and health reaches twenty. All of them are of great importance in the regulation of metabolism and physiological functions. Let's look at some of the vitamins in such aspects as distribution, biological role and signs of their deficiency in food.

Vitamins are divided into two groups: fat-soluble and water-soluble.

Vitamins A, D, E and K are fat-soluble vitamins. Vitamin A (retinol) is found in animal products such as animal and fish liver, butter, egg yolk, and in plant products, especially various types vegetables (carrots are the most famous in this regard). Fruits and vegetables also contain provitamin A (carotene).

Vitamin A is necessary for the growth process and normal vision. It promotes growth and regeneration of the skin and mucous membranes. In the absence of this vitamin, drying and keratinization of tissues occurs, as a result of which infections often develop. Damage to the cornea and connective tissue of the eyes can lead to complete loss of vision.

Vitamins of group D (calciferols) are found in fish products, and to a lesser extent in dairy products. Under the influence of sunlight, the body can synthesize this vitamin itself from certain precursors - provitamins. Vitamin D deficiency causes a disturbance in the metabolism of calcium and phosphorus, which is accompanied by softening, deformation of bones and other symptoms of rickets.

Vitamin E (tocopherol) is found in significant quantities in vegetable oils, germs of cereal seeds (barley, oats, rye and wheat), as well as in green vegetables. It is known that vitamin E can prevent the oxidation of certain substances (antioxidant effect). In animals, deficiency of this vitamin manifests itself mainly in dysfunction of the muscles and gonads.

Vitamin K (phylloquinone) is found in vegetables (spinach, green peas, etc.), fish, and meat. Insufficiency of this vitamin in humans can occur when resorption (absorption) in the gastrointestinal tract is impaired (for example, in diseases of the liver and gall bladder) or its synthesis by intestinal bacteria ceases. The lack of vitamin K manifests itself mainly in the occurrence of bleeding, since this vitamin is involved in the formation of a substance important for blood clotting - prothrombin.

From the group of water-soluble vitamins, consider B vitamins, vitamin C and bioflavonoids (vitamin P).

Vitamin B1 (thiamine) is found primarily in the germs and shells of grain seeds, yeast, nuts, legumes, as well as in some products of animal origin - heart, liver, kidneys. A rich source of this vitamin is black bread. As a component of certain enzymes, thiamine is important in carbohydrate metabolism, for example, at the stage of decarboxylation of pyruvic acid. It also takes part in the transformation of amino acids and is involved in protein and fat metabolism. Therefore, with an increase in the intake of carbohydrates into the body, the need for this vitamin increases. The same thing happens with an increase in the intensity of energy metabolism. Lack of this vitamin causes severe disorders of the nervous system (polyneuritis).

Vitamin B2 (riboflavin) is found in significant quantities in the liver, kidneys, yeast, and dairy products. The biological role of this vitamin is due to the fact that it is part of enzymes that catalyze redox reactions, as well as enzymes for amino acid metabolism and fatty acid oxidation. Therefore, with B2-avitaminosis, tissue respiration processes are weakened, which causes growth retardation, increased breakdown of tissue proteins, a decrease in the number of leukocytes in the blood, and dysfunction of the digestive organs. An increase in the amount of carbohydrates and fats in the diet leads to an increase in the need for riboflavin.

Vitamin B6 (pyridoxine) enters the body in foods such as wheat flour, legumes, yeast, liver, kidneys and some others, and is also produced by intestinal microbes. As part of transaminase enzymes that catalyze the transamination of amino acids, pyridoxine plays an important role in protein metabolism. Vitamin B6 is also of great importance in fat metabolism (lipotropic effect), in hematopoiesis, in the regulation of acidity and gastric secretion. Manifestations of vitamin B6 deficiency in animals are growth retardation, convulsions, etc. A person’s need for vitamin B6 increases with an increase in the amount of protein in food, as well as during physical activity.

B vitamins also include nicotinic acid (vitamin PP). A person receives nicotinic acid in bread, various cereals, liver, meat, and fish. The mechanism of the biological action of vitamin PP is associated with its participation in the functioning of a large number of enzymes that catalyze the processes of tissue respiration through hydrogen transfer. Nicotinic acid deficiency causes pellagra, a disease manifested in a combination of dermatitis, intestinal dysfunction and mental pathology.

Vitamin B12 (cyanocobalamin) enters the human body in products of animal origin (liver, kidneys, fish). The biological role of cyanocobalamin is its antianemic effect, as well as its participation in the synthesis of amino acids and nucleic acids. If the absorption of vitamin B12 is impaired, anemia develops, which is associated with inhibition of the formation of red blood cells.

Vitamin C (ascorbic acid) is found mainly in fresh vegetables and fruits. Rich sources of this vitamin are rose hips, black currants, citrus fruits, dill, sweet peppers, parsley, spinach, tomatoes, cabbage. Grinding and long-term storage, cooking and canning of these products can significantly reduce their vitamin C content.

The mechanism of action of ascorbic acid is associated with its ability to donate and attach a hydrogen atom, that is, with participation in redox processes. It is necessary for normal protein metabolism, for the formation of connective tissue, including in the walls of blood vessels, for the synthesis of adrenal steroid hormones, which play an important role in the body’s adaptation to stressful situations, etc.

Vitamin C deficiency causes a serious disease (scurvy), which is characterized by hemorrhages (due to increased fragility and permeability of the vascular walls), decreased physical performance, weakened function of the cardiovascular system, etc.

The need for ascorbic acid during intense muscle activity increases significantly. To increase physical performance, an increased supply of this vitamin to the body is necessary. However, its long-term consumption in quantities significantly exceeding the normal requirement can lead to the body becoming accustomed to increased doses. In this case, when returning to normal, normal amounts of vitamin C in the diet, symptoms of vitamin C deficiency may occur.

Much in common (synergy and parallelism) has been established in the action of vitamins C and P. Vitamin P is classified as bioflavonoids, the total number of which reaches one hundred and fifty. Vitamin P is found in plant foods. It has a capillary-strengthening effect and the ability to reduce the permeability of vascular walls. The mechanism of action of vitamin P is associated with the activation of oxidative processes. Lack of vitamin P in the diet causes capillary fragility and hemorrhage. Vitamin P enhances the reduction of dehydroascorbic acid into ascorbic acid.

Nutrient requirements show considerable variability. For example, one person's calcium or iron needs may be two or three times greater than another's. The individual needs of a person for vitamins are even less accurately determined. Therefore, quantitative indicators of the need for essential substances should be considered as indicative for planning the diet of healthy people.

IN Lately ideas about the role of vitamins in the body have been enriched with new data. It is believed that vitamins can improve the internal environment, increase the functionality of basic systems, and the body’s resistance to adverse factors. Therefore, vitamins are considered modern science about nutrition as an important means of general primary prevention of diseases, increasing efficiency, and slowing down the aging process.

There are different degrees of insufficiency of the body with vitamins: avitaminosis - complete depletion of vitamin reserves; hypovitaminosis - a sharp decrease in the supply of one or another vitamin. However, hypervitaminosis - an excess of vitamins in the body - is also dangerous. In principle, such situations should not arise for those involved in sports, since they will be excluded if the recommended diets are followed. But there is a so-called subnormal supply, which is associated with a deficiency of vitamins and manifests itself in disruption of metabolic processes in organs and tissues, but without obvious clinical signs. In our context, this means - without visible changes in the condition of the skin, hair and other external manifestations. But the trouble is that subnormal supply easily turns into a lack of supply of vitamins to the body with all the signs of trouble in the body, if this situation regularly repeats for various reasons.

Let's try to understand the possible reasons for the depletion of vitamin reserves in the body.

First of all, they are related to the quality of products and dishes prepared from them: non-compliance with storage conditions in terms of time and temperature, irrational culinary processing, for example, long and repeated cooking of finely chopped vegetables in order to destroy and get rid of nitrates and nitrites. The presence of antivitamin factors in food (cabbage, parsley, pumpkin, potatoes, green onions, apples contain a number of enzymes that destroy vitamin C, especially when cut small). In a salad of chopped onions and tomatoes with low acidity, vitamin C is easily destroyed by chlorophyll, and therefore it is rational to add table vinegar to this salad.

Vitamin A is destroyed when illuminated by ultraviolet rays, under the influence of atmospheric oxygen, or during strong and prolonged heating. So the presence of vitamins in vegetable stew prepared in country conditions is problematic. It is necessary to take into account some difference in the content of vitamins, calculated from reference materials for the average variety of any vegetables or fruits, and their actual content in a particular product. The deviation can be in either direction.

Another group of reasons is related to our health, and above all, to the function of the gastrointestinal tract. Many common chronic diseases interfere with the absorption or absorption of vitamins and minerals. That is, there were a lot or enough vitamins in the food eaten, but few of them entered the blood and organs. Congenital defects in vitamin metabolism are also possible, which are difficult for even a specialist to guess.

It is also known that a number of vitamins: B12, B6, vitamin H (biotin) are supplied to us by beneficial intestinal microflora, therefore severe intestinal disorders, improper use of antibiotics and other medications lead to the creation of a certain deficiency of these vitamins in the patient’s body.

It should be noted that there are reasons why the need for vitamins unexpectedly increases compared to the usual state. Most often this occurs during infectious diseases and stress.

Perhaps someone in such cases takes vitamins regularly, but most often they immediately forget about it as soon as they gain a little weight. A sharp change in climatic-geographical zone is also always accompanied by an increase in the need for vitamins (especially C, P, B1). Such physiological conditions of women as pregnancy and lactation require careful but mandatory additional fortification.

In conditions of environmental distress, damaging environmental factors require natural ways to protect the body. The main one is the intake of antioxidant vitamins: C, A and B-carotene, E.

The need for vitamins always increases with systematic physical activity (training). For every additional thousand kilocalories, the need for vitamins increases by 33%. Moreover, if the training is long and carried out in an aerobic mode, then the need for vitamins C and B1 increases noticeably. During intense training associated with the accumulation of muscle mass, the body requires more vitamin B6.

In table Table 6 provides summarized data on the main vitamins. It is interesting to note that our dependence on vitamins increases when incomplete protein is present in the diet. This happens with a vegetarian diet, as well as with an incorrect interpretation of nutrition rules during periods of sports training that differ in energy consumption. It is imperative to adhere to protein intake standards even on training days. It is very important to eat meat and fish with complex vegetable side dishes during and after regular blood loss to naturally restore the level of iron and copper in a woman’s body. In this combination, microelements, protein and vitamin C are better absorbed.

The above list of reasons for the occurrence of true vitamin deficiencies is far from complete, but it makes it possible to understand the complexity of our body’s natural dependence on environment, lifestyle, on the quality and quantity of food. And if we return to the external signs of vitamin deficiency, we must recall that dry skin, for example, is closely related to insufficient consumption and absorption of vitamins C, B2, B6, A; poor condition of hair and nails is evidence of a deficiency of vitamins A and C; pale lips are caused by a lack of vitamins C and B2; formation of acne - vitamin A.

As you know, the mandatory components of an athlete’s diet are vegetables, herbs, roots, fruits and berries in the required quantity and assortment.

The minimum required amount of vegetables is 400 g of eight types: cabbage, beets, carrots, turnips (radish, radish), tomatoes, cucumber, onion, garlic, as well as herbs - dill, parsley, celery, etc. Fruits and berries are required 300 g: apples, citrus fruits, currants. This required minimum can be increased provided that there is a little at each meal. There should be at least four meals, which will allow you to eat bulk plant foods in small portions for better digestibility.

It is clear that additional intake of multivitamins and minerals is possible and necessary not only at certain times in the fall, winter and early spring, but at any time of the year - in the presence of the above-mentioned factors.

Minerals, micro and macro elements

Minerals perform multiple functions in our body. As structural elements, they are part of bones and are contained in many enzymes that catalyze metabolism in the body. Minerals are found in hormones (for example, iodine in thyroid hormones).

The role of iron, which is part of blood hemoglobin, is well known. With its participation, oxygen is transported. Minerals activate certain processes and participate in the regulation of acid-base balance in the blood and other organs. Sodium and potassium take part in the transport of various substances into the cell, thereby ensuring its functioning. Minerals (potassium, calcium, sodium and magnesium) play an important role in regulating the function of cardiac and skeletal muscles.

A fairly high and constant content of salts in biological fluids, primarily potassium and sodium salts, contributes to the preservation of water in the cell, which is important for its normal functioning and preservation of shape.

The body's need for various minerals varies widely. The need for sodium is highest. Part of this element comes with food: the daily allowance of bread for healthy men contains 3.5 g of table salt and 3-5 g is added to food during its preparation. Thus, 10-15 g of table salt are consumed per day. This amount is quite enough to meet the body's sodium needs. Usually, more sodium chloride (table salt) is consumed than necessary. Salt is added to stimulate appetite; foods canned with added salt are widely used. Increased consumption of table salt is undesirable, as it leads to thirst, increased water consumption and water retention in the body. A systematic excess of table salt in the diet, as scientific studies have shown, contributes to an increase in the incidence of hypertension.

Another mineral element, potassium, is found in almost all foods; the need for it is estimated at approximately 4-6 g per day. A typical set of foods contains 5-6 g of potassium, more than half of which comes from vegetables and fruits, including about 2 g from potatoes. Potassium suppliers include bread and cereals, as well as animal products. Potassium is an important cellular element; unlike sodium, it does not contribute to water retention in the body. An essential function of potassium is its participation in the regulation of muscle excitability, especially the heart muscle. A lack of potassium can lead to convulsive contractions of skeletal muscles, decreased contractility of the heart muscle and disturbances in the rhythm of cardiac activity.

When justifying a higher potassium content in a set of products, it is necessary to take into account the specific features of its metabolism in the body. Under the influence of neuro-emotional stress and specific hormonal changes in athletes, there is an increased release of potassium from cells into the blood and its loss in the urine. With systematically repeated periods of neuro-emotional stress, potassium deficiency may occur in the body. Vegetables are the main source of potassium, so including vegetables in the daily diet is mandatory for everyone. Sometimes potassium salts are used to compensate for potassium deficiency.

Calcium is one of the main elements of our body. The need for this element is relatively small - about 0.8 g per day. Calcium plays a certain role in regulating the excitability of the nervous system, in the mechanism of muscle contraction, and blood clotting. IN standard set Cooking products contain about 1.2 g of calcium, mainly in products of animal origin. There are a lot of calcium salts in dairy products: milk, cottage cheese, cheese. They account for more than 60% of the calcium in the product range. Calcium contained in dairy products is well absorbed; it is less absorbed from other products. With increased fat content in the diet, calcium absorption is reduced. Some other nutrients (oxalic acid, phytin) also disrupt its metabolism.

The content of phosphorus in food, as well as its ratio with calcium, is of great importance. The optimal ratio between calcium and phosphorus is 1: (1.5-2.0), at which both elements are better absorbed. The bulk of the body's phosphorus is found in the bones. The most important high-energy compounds (ATP, creatine phosphate, etc.), which are energy accumulators for ensuring all body functions, contain phosphorus. It is also part of many other substances - catalyst proteins, nucleic acids, etc. An adult's need for phosphorus is 1.2 g per day. Phosphorus is found in almost all foods. Phosphorus is absorbed better from animal products than from plant products, but its content in the latter is quite high, so grain products and vegetables are good suppliers of phosphorus. About 0.6 g of phosphorus comes with bread and dough products, with cereals and pasta - 0.25 g; vegetables in a standard diet contain about 0.33 g of phosphorus.

Of the total amount of phosphorus, more than half comes from animal products. High consumption of organic phosphorus (mainly in the form of lecithin) is one of the factors that prevents the occurrence of significant disorders of lipid metabolism and normalizes cholesterol metabolism.

Mineral metabolism and the need for minerals are interconnected. This is especially clearly established in relation to calcium, phosphorus and magnesium. Magnesium takes part in the regulation of nervous system excitability and muscle contraction. Magnesium is required less than calcium; their optimal ratio in the diet is considered to be 0.6:1. The magnesium requirement of an adult is approximately 0.4 g per day. The main sources of this element are bread and cereals, which account for half of all magnesium, so cereals and bread in certain quantities are part of the daily diet. Vegetables contain 0.14 g of magnesium [Hereinafter, the content of elements is given per 100 g of the edible part of the product]. Animal products contain less magnesium (0.12 g).

Microelements are a large group of chemical substances that are present in the human and animal body in low concentrations, expressed in micrograms per 1 g of tissue mass. These concentrations are tens and hundreds of times lower than the concentrations of the so-called macroelements (calcium, phosphorus, potassium, sodium, magnesium, chlorine, sulfur). Microelements have a pronounced mutual influence associated with their interaction at the level of absorption in the gastrointestinal tract, transport and participation in various metabolic reactions. In particular, an excess of one micronutrient can cause a deficiency of another. In this regard, a careful balance of food rations in terms of their microelement composition is of particular importance, and any deviation from the optimal ratios between individual microelements can lead to the development of serious pathological changes in the body.

If the intake of mineral components is insufficient, the body can, for some time, make up for the created deficiency by mobilizing them from tissue depots, and if there is an excess intake, by increasing excretion.

The body's tissue depots have powerful reserves of macroelements (calcium, magnesium - bone tissue, potassium - muscles, sodium - skin and subcutaneous tissue), while the reserves of microelements in tissues are insignificant. This explains the low adaptation capabilities of the body to a deficiency of microelements in food.

The works of Russian scientists (V. Ya. Rusin, V. V. Nasolodin) convincingly show that the metabolism of essential microelements is intensified during serious physical activity, which means that the need for them in athletes is much higher compared to other groups of the population.

The most studied of the microelements is iron. The body's need for it is small: 10 mg per day for men and 18 mg for women. Iron is found in bread (10.0 mg), vegetables (10.5 mg), meat, fish, poultry (7.4 mg each). With other products (cereals, milk, cheese, cottage cheese) little iron is supplied (about 1.3 mg). The absorption of iron from the diet within 10% is taken as the norm. Although animal products contain less iron, it is better absorbed. An increased iron content in the diet can protect against unwanted dysfunctions of the hematopoietic organs. Excess iron is easily removed from the body.

Issues of iron supply in the body occupy one of the central places in the general problem of adequate nutrition, which is due, on the one hand, to the specific role of iron, and on the other, to the fact that iron deficiency conditions are one of the most common types of nutritional deficiency even in highly developed countries.

results scientific research, obtained in the last 10-15 years, have significantly expanded our understanding of the importance of iron, which forces us to solve in many ways such practical issues as assessing the ferrostatus of athletes, organizing preventive and therapeutic measures when identifying iron deficiency, and developing new high-quality dosage forms of iron and etc.

This problem is of particular interest for sports practice, since a direct connection has been established between the level of iron supply in the body and physical performance. It is determined by the participation of iron, first of all, in aerobic metabolism at the level of at least four of its units:

transport of blood oxygen by hemoglobin,

transport and storage of oxygen in muscle by myoglobin,

electron transport in the respiratory chain by cytochromes and cytochrome oxidase,

activity of a number of NAD-dependent dehydrogenases and succinate dehydrogenase.

In case of iron deficiency in the body, all parts of aerobic metabolism suffer, but primarily the tissue respiration system, which is due to the very high rate of renewal of heme-containing enzymes, in particular cytochromes. This circumstance gives grounds to assert that metabolic disorders caused by iron deficiency at the tissue level may have more serious biochemical and physiological consequences for the manifestation of maximum physical performance than hematological ones.

The risk of developing iron deficiency states in actively training athletes is quite high, which is due to reasons of both exogenous and endogenous nature. Against the background of very high physical and neuro-emotional stress, firstly, the natural loss of iron from the body through the gastrointestinal tract, kidneys and especially through the skin with sweat increases significantly, secondly, the adaptive synthesis of iron-containing proteins - hemoglobin, myoglobin, increases cytochromes, iron-dependent dehydrogenases.

An increase in the body's need for iron cannot always be satisfied through dietary iron. In such situations, the only way to ensure a high level of functioning of iron-dependent aerobic metabolism systems is redistribution common pool iron, First of all, due to reserve, and then - tissue iron of other iron-dependent systems. The latter currently include the immune system, collagen formation systems, detoxification of xenobiotics (including drugs), inactivation of biologically active substances, as well as lipid and neurotransmitter metabolism systems.

In close connection with iron metabolism in the human body there is another microelement - copper, the content of which on average is 75-150 mg. Copper is found in many organs, with the highest concentrations in the liver, brain, heart and kidneys. The main amount of copper (about 50%) is found, however, in muscle and bone tissue. The liver contains 10% of the total amount of copper in the body.

Copper is involved in the construction of a number of enzymes and proteins. The role of copper in ensuring physiological and biochemical processes during physical activity is great. It is associated with the participation of this microelement in the regulation of biological oxidation and ATP generation, in the synthesis of the most important connective tissue proteins (collagen and elastin) and in iron metabolism.

Copper is a hematopoietic microelement that is actively involved in the synthesis of hemoglobin and the formation of other iron porphyrins. The function of copper in hemoglobin synthesis is closely related to the function of iron. Copper is necessary to convert dietary iron into an organically bound form, as well as to stimulate the maturation of reticulocytes and their conversion into red blood cells. In addition, it promotes the transfer of iron to the bone marrow.

The daily requirement for copper is about 80 mcg/kg for young children, 40 mcg/kg for older children and 30 mcg/kg for adults. Among food products, copper content is highest in the liver, as well as in seafood, legumes, buckwheat and oatmeal, nuts, and very low in milk and dairy products.

The adult body contains a fairly large amount (2-3 g) of zinc. The bulk of zinc is concentrated in bones and skin. Zinc levels are highest in sperm and prostate gland. Its concentration is also quite high in bones and hair; in internal organs it is much less. Zinc is found in organs and tissues mainly in organically bound form in the form of easily dissociable compounds with protein.

The biological role of zinc is determined by its need for normal growth, development and puberty, maintenance of reproductive function, hematopoiesis, taste and smell, normal wound healing processes, etc. Zinc is necessary for the normal function of the pituitary gland, pancreas, testicular and prostate glands.

Zinc affects the activity of hormones of the pituitary gland, adrenal glands and pancreas. Under the influence of its compounds, the activity of gonadotropic hormones of the pituitary gland increases. The participation of zinc in the biological action of insulin has been established: there is evidence that the hypoglycemic effect of insulin depends on zinc, which is constantly present in insulin. Zinc has lipotropic properties, normalizing fat metabolism, increasing the intensity of fat breakdown in the body and preventing fatty liver.

This active role of zinc in the regulation of the metabolism of carbohydrates and fats determines its high importance in the nutrition of athletes and athletes, especially during aerobic exercise, and people suffering from excess body weight and diabetes.

With food, an adult should receive 10-22 mg of zinc per day, pregnant women - 10-30 mg, lactating women - 13-54 mg. The greatest need for zinc appears during periods of intensive growth and puberty, as well as during physical activity. The main food sources of zinc: meat, poultry, hard cheeses, as well as legumes and some cereals. High levels of zinc are found in shrimp and nuts. Milk and dairy products are low in zinc.

The adult human body contains 12-20 mg of manganese. Its level is especially high in the brain, liver, kidneys, and pancreas.

Manganese is necessary for normal growth, maintenance of reproductive function, osteogenesis processes, and normal metabolism of connective tissue. It is also involved in the regulation of carbohydrate and lipid metabolism and actively stimulates cholesterol biosynthesis. The introduction of manganese has a hypoglycemic effect. In the blood and tissues of patients diabetes mellitus manganese concentration is reduced. It is believed that manganese is involved in the synthesis or metabolism of insulin.

An important aspect of the biological effect of manganese is its lipotropic properties. It prevents fatty liver and promotes overall fat utilization in the body. Manganese is also closely related to the processes of protein and nucleic acid synthesis. The connection of this microelement with the function of endocrine systems, its effect on the gonads, sexual development and reproduction has been established.

There is no reliable information about human physiological needs for manganese. It is assumed that the minimum daily requirement for manganese for an adult is 2-3 mg, and the recommended level of consumption is 5-10 mg. Most characteristic symptom Manganese deficiency is caused by severe hypocholesterolemia, as well as weight loss, dermatitis, nausea, and vomiting. Manganese stimulates growth processes. A manifestation of manganese deficiency is growth retardation. Thus, it becomes clear that an adequate amount of manganese in food is very important during strength and developmental physical activity, especially in young men.

Chromium is involved in the regulation of carbohydrate and lipid metabolism and in maintaining normal glucose tolerance. Its role in the regulation of cholesterol metabolism is noticeable. Administration of chromium to patients in some cases causes a marked decrease in blood cholesterol levels.

Chromium is an activator of a number of enzymes (phosphoglucomutase, trypsin, etc.). Very high chromium contents have been found in some nucleoprotein fractions, but the role of chromium in nucleic acid metabolism remains unclear.

Chromium is found in foods in fairly low concentrations. With a normal mixed diet, it enters the body in quantities that only slightly exceed the lower limit of the physiological need of adults for this microelement. With an unbalanced diet and monotonous diet, a relative deficiency of chromium occurs quite quickly. A person should receive 200-250 mcg of chromium per day from food. The chromium content is highest in beef liver, meat, poultry, legumes, pearl barley, rye wallpaper flour. The highest biological activity of chromium is found in baker's yeast, liver, and wholemeal wheat flour.

Along with zinc, manganese, copper and iron, chromium is the most valuable microelement in the nutrition of athletes during prolonged aerobic exercise, when the role of carbohydrates and fats in the energy supply of the body increases significantly, especially during the competitive period.

The adult body contains 20-50 mg of iodine, of which about 8 mg is concentrated in the thyroid gland. Iodine, contained in water and food products in the form of inorganic iodides, is quickly absorbed in the intestines.

Iodine is the only currently known trace element that plays an active role in the biosynthesis of hormones. It is involved in the formation of the thyroid hormone - thyroxine. Up to 90% of organic iodine circulating in the blood comes from thyroxine. This hormone controls the state of energy metabolism, the intensity of basal metabolism and the level of heat production. It actively affects physical and mental development, differentiation and maturation of tissues, participates in the regulation of the functional state of the central nervous system and emotional tone of a person, and affects the activity of the cardiovascular system and liver. Thyroxine interacts with other endocrine glands (especially the pituitary gland and gonads), has a pronounced effect on water-salt metabolism, the metabolism of proteins, lipids and carbohydrates, enhancing metabolic processes in the body.

Iodine deficiency in humans leads to the development of endemic goiter, which indicates a violation of thyroxine synthesis and suppression of thyroid function. This disease is typically endemic in nature and occurs only in those areas (biogeochemical provinces) where the iodine content in soil, water and local food products is noticeably reduced.

According to individual studies, the occurrence of the disease is associated with the level of manganese, fluorine, cobalt and other trace elements, as well as calcium and phosphorus, in the soil and local food products. General malnutrition and insufficiency of protein, fat, etc. in the diet are of great importance in the spread of goiter.

In areas of iodine deficiency, endemic goiter most affects school-age children, boys and girls during puberty, in whom a restructuring of the endocrine system occurs.

In modern socio-economic conditions, when the use of complex, expensive mineral fertilizers containing microelements and iodine, among other things, has been sharply reduced, the iodine content in food products has also fallen, especially in continental regions.

Iodine is distributed unevenly in nature. Its greatest quantities are concentrated in sea water, in the air and soil of coastal areas, where the highest iodine content is observed in local plant products (cereals, vegetables, potatoes, fruits) and in products of animal origin (meat, milk, eggs). As you move away from the sea, the iodine content in the external environment gradually decreases. The lowest iodine content in the external environment is found in mountainous areas, where water, soil, air and local food products are extremely depleted in iodine. The physiological need for iodine is 100-150 mcg per day.

The iodine content in the same foods varies significantly depending on its concentration in the soil and water in a given area. Exceptionally high iodine content in seaweed(up to 160-800 mg/100 g in dry kelp, 200-220 mg/100 g in dry seaweed). Large amounts of iodine are found in sea fish and seafood. The iodine content in meat and dairy products averages about 7-16 mcg/100 g of edible portion.

Storage and culinary processing of food products lead to significant losses (up to 65%) of iodine. When using iodized salt for cooking, losses during heat treatment are 22-60%.

The physiological role of fluoride is significant in bone formation and the formation of dentin and tooth enamel. Adequate human intake of fluoride is essential to prevent dental caries and osteoporosis.

Fluoride is unevenly distributed in the body. Its concentration in teeth is 246-560 mg/kg, in bones - 200-490 mg/kg, and in muscles does not exceed 2-3 mg/kg. Fluorine also plays an important role in bone formation and normalizes phosphorus-calcium metabolism. With age, the amount of fluoride in the body (mainly in the bones) increases. Fluoride deposition in tooth enamel occurs mainly in childhood during the formation and growth of permanent teeth.

The daily requirement for fluoride has not been precisely established. Both excess and lack of fluoride intake are equally unfavorable for the body; the optimum fluoride intake is very limited. Excessive intake of fluoride into the body causes the development of fluorosis, manifested by mottling of tooth enamel. Fluorosis is an endemic disease that occurs in areas where the fluoride content in water exceeds 2 mg/l. The fluorine content in such water can be reduced by special treatment of water in ion exchangers, ensuring its defluoridation. Insufficient intake of fluoride into the body leads to dental damage, expressed in the intensive development of dental caries.

Cobalt is one of the most important microelements involved in hematopoiesis. It is involved in the formation of red blood cells and hemoglobin and thus stimulates hematopoiesis. Cobalt is the main starting material for the endogenous synthesis of vitamin B12 in the body. The largest amount of cobalt is found in the pancreas. Apparently, it is associated with the function of this gland and is involved in the formation of insulin. Satisfaction of the body's need for vitamin B12 occurs, along with its intake in food, also due to the synthesis by intestinal microflora from cobalt, also supplied with food.

Cobalt is common in natural foods in small quantities, but with a mixed diet it is enough to satisfy the body's needs. This microelement is found in water (river, lake, sea), in marine plants, in the body of fish and animals. The body's need for cobalt has not yet been established (approximately 100-200 mcg/day).

The biological role of nickel is not well understood. Its biological action has many similarities with cobalt in terms of stimulating hematopoietic processes. Nickel is found in large quantities in plant products growing on the soils of “nickel” areas, in sea, river and lake water, in the bodies of terrestrial and most marine animals and fish. It is especially abundant in the liver, pancreas and pituitary gland. The need for nickel has not been established.

The main biological significance of strontium is in the construction of bone tissue, in which its content is 0.024% in terms of ash.

Nutritional and biological value of vegetables, herbs, roots, herbs, fruits and berries

Vegetables, fruits and berries are of exceptional importance in nutrition. A deficiency of this part of the diet is the most common nutritional mistake, leading to serious negative consequences. Immunodeficiency, infectious diseases, manifestations of negative heredity and other troubles can be prevented or significantly weakened if we understand the role of vitamin-like factors, biologically active substances in general, macro- and microelements in human nutrition during its adaptation to the real environment.

Vegetables and fruits are among those products that can least be replaced with any other food products. The importance of vegetables and fruits as food products lies in the fact that they are the main suppliers of: vitamins, pectin fibers and active fiber, alkaline mineral elements, organic acids and carbohydrates.

Important physiological properties of vegetables and fruits include their effect on the functioning of the digestive glands. In addition, they normalize the vital activity of beneficial intestinal microflora, reduce the intensity of putrefactive processes, increase the motor function of the stomach and intestines, enhance peristalsis and thus improve bowel movements. Vegetables and fruits are of great importance for maintaining acid-base balance in the body and preventing acidotic changes. They contain a balanced active complex of minerals that have an alkalizing effect in the body.

The biological composition of vegetables, fruits and herbs is extremely rich. They contain all vital nutritional components.

Carbohydrates. The carbohydrate content in most vegetables does not exceed 5%, but in some of them, for example in potatoes, the amount of carbohydrates reaches 20%, in green peas - 13%, etc. Carbohydrates in vegetables are mainly represented by starch and, to a lesser extent, sugars , with the exception of beets and carrots, which are dominated by sugar. Fruits are richer in carbohydrates than vegetables (on average they contain 10% carbohydrates).

Sugars (glucose, fructose, sucrose) are most fully represented in fruits. A special feature of sugars in fruits and vegetables is their significant fructose content. In vegetables, sugar is also presented in three types - glucose, fructose and sucrose. The largest amount of sugars is found in carrots (7.0%), beets (9.0%), watermelons (8.7%) and melons (9.0%). Other vegetables contain little sugar. Sucrose predominates in carrots, beets and melon. Watermelons are an exceptionally rich source of fructose.

Fiber is widely represented in vegetables and fruits (1-2%). Berries are especially high in fiber (3-5%). Fiber, as you know, is a difficult-to-digest substance. Vegetables and fruits (potatoes, cabbage, apples, peaches, etc.) are a source of predominantly soft fiber, which is broken down and absorbed quite fully.

In the light of modern scientific ideas, fiber from vegetables and fruits is considered as a substance that promotes the removal of cholesterol from the body, and also has a normalizing effect on the vital activity of beneficial intestinal microflora.

Pectin substances. In vegetables and fruits, pectin substances are presented in the form of protopectin - a dense, insoluble substance contained in cell walls, and pectin - a soluble substance found in cell sap. Protopectin, when broken down, can serve as a source of pectin. The breakdown of protopectin occurs under the influence of the enzyme protopectinase, as well as during boiling. The rigidity of unripe fruits is explained by the significant content of protopectin in them; During the ripening process, protopectin is broken down, the fruits become softer and enriched with pectin. Ripe vegetables and fruits are much richer in pectin than unripe ones. When fruits are heated, protopectin also breaks down, releasing pectin, so baked fruits, e.g. baked apples, richer in pectin than raw ones.

Apricots........................4.0-7.1

Oranges (pulp) .......12.4

Cherry........................11.4

Plum................................3.1-8.0

Pear........................3.3-6.3

Apples........................1.6-5.6

Radish.............................10.3-10.9

Beet...................4.8-7.2

Carrots........................2.4-4.8

You may notice that oranges, cherries and radishes are richest in pectin.

Mineral elements. Vegetables and fruits are a rich source of various mineral salts: potassium, calcium, magnesium, phosphorus, iron, etc. The salt composition of vegetables and fruits is characterized by an alkaline reaction. In this regard, they play an important role in maintaining the acid-base state of the body. Vegetables and fruits are the main suppliers of potassium and iron, which makes them important in the mineral supply of the body.

Potatoes have a high potassium content (568 mg per 100 g of edible portion), which ensures the body's need for potassium (2500-5000 mg). There is a lot of potassium in dry fruits. For example, dried apricots (dry apricots) contain 1717 mg of potassium per 100 g of edible part, prunes - 864 mg, raisins - 860 mg, etc. Apricots, quince, pears, plums, apples, melon, etc. are rich in iron. Significant amounts of iron are found in white cabbage, carrots, oranges, and cherries.

Iron from vegetables and fruits is well absorbed and is most fully used in the body. This is explained by the presence of ascorbic acid and other substances in vegetables and fruits.

Vitamins. In ensuring the vitamin content of nutrition and satisfying the body's need for vitamins, vegetables and fruits occupy one of the first places. They contain vitamin C, P-active substances, carotene (provitamin A) and almost the entire group of B vitamins. Vegetables and fruits are especially important as suppliers of vitamins C, P and carotene. We can assume that the body is provided with these vitamins exclusively through vegetables and fruits.

The most important of the vitamins contained in vegetables and fruits is vitamin C. Rose hips, black currants, citrus fruits, etc. are known to be high in vitamin C. However, the body is provided with vitamin C mainly through ordinary, daily consumed vegetables and fruits - potatoes, cabbage, garden greens, onions, etc.

Fresh vegetables, fruits, and berries have the highest content of vitamin C. Thus, 100 g of potatoes immediately after harvest contains 25 mg of vitamin C, and in winter - only about 10 mg. Unripe fruits, like overripe ones, contain less vitamin C.

Vegetables and fruits supply the body with vitamin P (or P-active substances). The biological action of P-active substances has much in common with the action of vitamin C. Synergism has been noted, i.e., mutual enhancement of the action when these vitamins are used together.

The third most important vitamin, supplied primarily by vegetables and fruits, is vitamin A in the form of the provitamin carotene. According to modern scientific data, carotene plays an independent important role in the function of the adrenal glands and in the formation of adrenal hormone. Carrots contain a lot of carotene (9 mg per 100 g of product). This amount exceeds daily norm carotene for humans. The carotene content is significant in tomatoes, apricots, onions, green peas and other plant products colored orange and green.

Vegetables and fruits also contain other vitamins: B1, B2, PP, K, inositol, choline, etc. Vegetables, especially leafy ones, are a source of folacin, which is involved in hematopoiesis. Consumption of raw vegetables allows you to most fully satisfy the body's need for vitamins.

Organic acids. The most important component of fruits and berries, as well as some vegetables (tomatoes, sorrel, etc.) are organic acids, which not only have a taste value, but also participate in some metabolic processes and digestive processes. Organic acids contribute to alkalization of the body. Including a large number of alkaline components, during the process of transformations in the body they are oxidized to carbon dioxide (CO2) and water (H2O) and leave a significant supply of alkaline equivalents in the body. Organic acids affect the digestive processes, being strong stimulants of pancreatic secretion and intestinal motor function.

Organic acids are present in fruits in a wide variety. The fruits contain mainly malic, citric and tartaric acids. Malic acid predominates in fruits, and citric acid predominates in berries. Citrus fruits contain a significant amount of citric acid (in lemons - 6-8%). Grapes contain tartaric acid (0.2-0.8%). A small amount of tartaric acid is found in red currants, gooseberries, lingonberries, strawberries, plums, apricots, etc. Traces of succinic, oxalic, formic, benzoic and salicylic acids are found in some fruits. Succinic acid is found mainly in unripe fruits, gooseberries, currants, grapes, salicylic acid - in strawberries, raspberries, cherries, formic acid - in raspberries.

Particular attention should be paid to oxalic acid, which is associated with a number of adverse effects on the body. Most often, vegetables and fruits with a high content of oxalic acid are limited in the diet. These include sorrel, spinach, rhubarb, and figs. 100 g of sorrel contains 360 mg of oxalic acid, 100 g of spinach - 320 mg, rhubarb - 240 mg, fig - 100 mg. Oxalic acid forms unfavorable bonds that contribute to metabolic disorders, especially salt metabolism. It can be formed in the body itself from carbohydrates, as well as during the metabolism of ascorbic acid. To some extent, the source of oxalic acid is such a daily consumed product as beets (100 mg per 100 g of product).

Essential oils. The biological role and physiological significance of essential oils present in vegetables and fruits have not been sufficiently studied. First of all, essential oils give plant products taste color. By acting on the olfactory centers, essential oils enhance the secretion of digestive juices and thus improve digestion. There is evidence of the stimulating effect of aromatic substances on the nervous system. The presence of essential oils in garlic, onions, and oranges is very pronounced. In oranges, essential oils are concentrated mainly in the peel (zest); the amount of essential oil in it is 1.2-2.1% by weight of the skin. Orange essential oil contains citral, linalool, etc.

However, the effect of essential oils on the body cannot be considered unambiguously beneficial. Vegetables and fruits with a high content of essential oils have an irritating effect on the secretory apparatus, mucous membranes of the digestive tract, kidneys, etc.

Vegetables as digestive stimulants. One of the important physiological properties of vegetables is their stimulating effect on the secretory function of all digestive glands, and vegetables retain this ability even with different forms of processing (juice, soups, purees). Cabbage has the greatest juice-killing effect, carrots the least. Vegetables regulate gastric secretion, and therefore the use of various combinations of vegetables with other foods makes it possible to influence the processes of gastric digestion in the required direction. The inhibitory effect of raw undiluted vegetable juices - cabbage, beetroot, potato, etc. - is known to inhibit gastric secretion. Raw potato juice is successfully used to reduce gastric secretion and for treatment peptic ulcer stomach and duodenum. Perhaps the therapeutic effect of raw potato juice depends on the solanine it contains, which has an atropine-like effect. Vegetables stimulate bile formation. The juices of radishes, turnips and carrots are the most active in this regard. The effect of vegetables on biliary function and the flow of bile into duodenum expressed to a small extent. The combination of vegetables with fats is most effective in stimulating bile formation and increasing bile secretion. Vegetables also have a significant effect on the secretion of the pancreas: whole vegetable juices inhibit secretion, and diluted juices stimulate it.

The most important property of vegetables is their ability to increase the digestibility of proteins, fats, and carbohydrates.

Spicy vegetables. Spicy vegetables are a necessary part of most dishes used in everyday nutrition. Unlike herbs (spices), they have pronounced biological activity and contain vitamins C, B6, carotene, and folacin. This complex of vitamins exhibits a biological effect even with a relatively small amount of spicy vegetables in the diet.

Dill. The specific aroma of dill is determined by the presence of essential oil containing aromatic substances such as phelandrene, terminene, limonene, carvone and aniol. The essential oil content in dill reaches 2.5%. Young plants (up to 10 cm in height) are used as a seasoning for food. Older plants with coarsened stems are used as an aromatic spice when pickling cucumbers and preparing marinades. 100 g of dill contains 100 mg of ascorbic acid. Chewing dill seeds after a heavy fatty meal improves digestion and relieves the feeling of heaviness in the stomach.

Parsley. The leaves and roots of parsley contain essential oil, which gives it its characteristic smell. There are root and leaf parsley: the first uses roots and leaves for food, the second uses only leaves. 100 g of parsley contains 1.7 mg of B-carotene and 150 mg of ascorbic acid. Parsley is characterized by a high iron content (1.9 mg).

Onion. There are several types of onions used in food. The most famous are onions, leeks and spring onions. The pungent odor of onions depends on the content of essential onion oil, which contains sulfides. The amount of essential oil in onions is 0.037-0.055%. Onions contain a variety of minerals and vitamins. Green onions (feathers) are of greatest vitamin value. 100 g of green onions contain 10 mg of ascorbic acid, 100 g of leeks - 35 mg, onions - 10 mg. Green onions are characterized by a high content of B-carotene (2.0 mg per 100 g).

Garlic. Garlic is a spicy vegetable with a strong taste and aromatic properties. It contains essential oil (0.005-0.009 g per 100 g). Garlic is of no value as a source of ascorbic acid, but it has bactericidal properties due to the phytoncides it contains. Garlic matters and how medicinal plant. It is used in the treatment of vascular and many other diseases.

Horseradish. The pungent taste of horseradish depends on the presence of allyl mustard oil; the amount of essential oil in horseradish is 0.05 g per 100 g. Horseradish has a high content of ascorbic acid (55 g per 100 g) and is a source of phytoncides.

Many herbs and roots are used as herbs in different countries and regions. The need for spicy vegetables is about 2% of the total vegetable consumption.

Rhubarb. From the leaves and petioles of rhubarb, cut before the plant blooms, you can prepare salads, jelly, compote, and pie filling. It is important that rhubarb preparations do not disrupt the digestive processes, do not affect the secretion of the gastrointestinal tract, but enhance peristalsis only at the level of the large intestine.

Borage is an ancient medicinal plant. Its leaves with the smell of fresh cucumber are added to vinaigrettes, okroshka, and cold borscht. Borage has a beneficial effect on metabolism.

It’s not for nothing that young lettuce leaves are called the breakfast of kings. Indeed, no other plant has such a delicate and refined taste. Its healing properties have been known for a long time. The substance contained in the salad - lactucin - calms the nervous system, improves sleep, and reduces the incidence of atherosclerosis. Organic acids prevent salt deposition. Pectins stimulate the intestinal tract. Lettuce leaves contain almost all known vitamins. The leaves are eaten fresh, separately or together with radishes and cucumbers; You can make sandwiches out of them.

Spinach contains proteins, sugar, ascorbic acid, B vitamins, vitamins P, K, E, D, minerals: magnesium, potassium, phosphorus, calcium, iron, iodine. All this makes spinach one of the most valuable dietary products. It contains secretin, which has a beneficial effect on the functioning of the stomach and pancreas. Spinach is especially useful for anemia.

Sorrel, which is used before flowering, improves digestion and reduces putrefactive fermentation in the intestines. Traditional medicine recommends sorrel juice as a choleretic agent. It is also a rich source of vitamin B. Sorrel leaves can be dried without losing their nutritional properties.

Nettle contains a huge amount of bioactive substances - organic acids, mineral salts of iron, phosphorus, silicon, vitamin K, vitamin C, protein and tannins. IN medicinal purposes Its tonic and choleretic properties are used.

Dandelion leaves contain many vitamins and microelements; a salad of them stimulates the secretion of bile and improves appetite. Dandelion roots can be used to make a chicory substitute. Dandelion roots contain polysaccharides, organic acids, vitamins and microelements.

Water and thirst

In the adult human body, water makes up 60% of the total body weight. The water content in different tissues is not the same. In connective and supporting tissues it is less than in the liver and spleen, where it is 70-80%.

In the body, water is distributed inside and outside cells. Extracellular fluid contains approximately 1/3 of all water, it contains many sodium ions, chlorides and bicarbonates; In the intracellular fluid, which includes 2/3 of the water reserves, potassium, phosphate ester anions and proteins are concentrated.

Water enters the human body in two forms: in the form of liquid - 48%, and as part of solid food - 40%. The remaining 12% is formed in the processes of metabolism of nutrients. The process of water renewal in the body occurs at high speed: for example, 70% of the water in the blood plasma is renewed in 1 minute. All tissues of the body participate in water exchange, but most intensively - the kidneys, skin, lungs and gastrointestinal tract. The main organ that regulates water-salt metabolism is the kidneys, but it should be borne in mind that the amount and composition of urine excreted can vary significantly. Depending on the operating conditions and the composition of the liquid and food consumed, the amount of urine can range from 0.5 to 2.5 liters per day. Water loss through the skin occurs through sweating and direct evaporation. In the latter case, 200-300 ml of water per day is usually released, while the amount of sweat depends more on environmental conditions and the nature of physical activity. With exhaled air, up to 500 ml of water is released through the lungs in the form of vapor. This amount increases as physical stress on the body increases. Typically, inhaled air contains 1.5% water, while exhaled air contains about 6%. The gastrointestinal tract plays an active role in the regulation of water-salt metabolism, into which digestive juices are continuously secreted, and their total amount can reach 8 liters per day. Most of these juices are absorbed again and no more than 4% are excreted from the body in feces. The organs involved in the regulation of water-salt metabolism include the liver, which is capable of retaining large amounts of fluid.

When a person, especially an athlete, loses fluid, certain symptoms appear. Losing 1% of water causes thirst; 2% - decrease in endurance; 3% - decrease in strength; 5% - decreased salivation and urination, increased heart rate, apathy, muscle weakness, nausea. As a result of intense physical activity, two processes occur simultaneously in the body of athletes: the formation of heat and its release by radiation into the environment and by evaporation of sweat from the surface of the body and heating of the inhaled air. When sweating and evaporating 1 liter of sweat, the body releases 600 kcal. This process is accompanied by cooling of the skin. As a result, body temperature is regulated. Mineral salts are released along with sweat (usually athletes say that sweat is salty and burns the eyes). Under the influence of training, the body adapts to the conditions of both heating and cooling microclimates. Thermoregulation in an athlete during muscular work is closely related to the state of water-salt metabolism and requires increased fluid consumption in the form of special drinks.

It is known that good nutrition, ensuring optimal metabolic processes, at the same time has a significant impact on the child’s body’s resistance and the development of immunity to various diseases, increases his performance and endurance, and promotes normal physical and neuropsychic development. In modern conditions, the importance of nutrition increases significantly due to the influence on the formation of a growing organism of such social factors as a sharp acceleration of the pace of life, an increase in the amount of cognitive information received, changes in the conditions of upbringing in the family, and involvement in activities. physical culture and sports, etc. Nutrition is, although not the only, but the most important reason for a new biological phenomenon observed recently throughout the world - acceleration - accelerated physical development and puberty of children and adolescents.

It has been established that children’s need for food depends on age, body weight, gender, climatic conditions, time of year. But all this is dominated by age.

While a child is studying at school, his body undergoes a significant leap in development. Height increases by 40-50 cm, body weight - more than 1 ia 30 kg, chest circumference - by 20 cm. Ossification and growth of the skeleton continues for ten years, which is determined by a high level of mineral metabolism. Are developing internal organs, nerve cells of the brain. The volume of the heart increases annually by approximately 25%. Vital capacity (vital capacity of the lungs) increases in boys from 1400 ml at 7 years old to 2000 ml at 11 years old and to 2700 ml at 15 years old, in girls - respectively from 1200 ml to 1900 ml and to 2500-2600 ml. Gastric capacity reaches 750-800 ml by the age of 10 and 1500-2000 ml by the age of 16 in boys and girls. From K) years of age, increased intestinal growth begins. At 14-15 years of age, the liver grows most actively. The composition and quality of blood in the body of a 7-12 year old child does not differ significantly from those in an adult. For 7-10 years of age, the stability of nervous processes in the central nervous system is characteristic. At 11-13 years of age, secondary sexual characteristics appear, and the endocrine glands begin to function intensively. The nervous system at this age is unstable. During puberty, the endocrine glands undergo significant restructuring. The excitability of the nerve centers of the cerebral cortex sharply increases and the processes of inhibition are weakened. During adolescence, internal organs are finally formed and the muscular system intensively develops. The most active growth of muscle mass occurs between 15 and 17 years. At 16 years old it makes up 44.2% of the total body weight (at 8 years old - 27.2%). By this time, the formation of the innervation apparatus of the muscles is completed and coordination of movements reaches the highest level.

Taking into account the physiological and biochemical characteristics of the body of children and adolescents, the following age criteria have been established that determine the needs for basic nutrients and energy: primary school - 7-10 years, middle - 11-13 years and senior, or teenage, age - 14-17 years .

Currently, sport occupies a significant place in the lives of the younger generation. The peculiarities of the course of biochemical and physiological processes, caused by the influence of systematic muscular activity, require appropriate changes in the nutrition of young athletes.

When organizing nutrition for young athletes, the main attention should be paid to compliance with the following provisions:

Correspondence of calorie intake to daily energy expenditure;

Correspondence of the chemical composition, calorie content and volume of the diet to the age needs and characteristics of the body, taking into account the type of sport and the preparation period;

A balanced ratio of essential nutrients in the diet;

Using a wide and varied range of products in the diet with the obligatory inclusion of vegetables, fruits, juices, herbs;

Replacement of missing products only with equivalent ones (especially in terms of protein and fat content);

Maintaining an optimal diet.

The need of young athletes for energy and basic nutrients is presented in table. 14 and 15.

The energy expenditure of young athletes is significantly higher than that of their peers who do not engage in sports. It should be taken into account that sports activity is characterized by intensity and unevenness of energy consumption, often combined with neuropsychic stress, which can significantly increase energy consumption. In young athletes, energy consumption associated with motor activity amounts to 34-38% of total energy consumption per day.

Proteins play a special role in the nutrition of children and adolescents involved in sports. A lack of protein in the diet retards growth, reduces resistance to infectious diseases, and affects mental development. At the same time, excess protein in the diet is undesirable. It reduces resistance to stressful situations and causes premature puberty.

As you know, active sports require changes in the consumption of animal and plant proteins. In the diet of young athletes, the share of animal proteins (meat, offal, fish, poultry, cottage cheese, cheese, eggs, milk) should be at least 60%, which will ensure the required optimum amino acid composition. The remaining 40% comes from plant proteins. This ratio of animal and plant proteins is recommended to be observed at every meal. In special cases, animal proteins can make up 80%. For example, during training aimed at developing such qualities as speed and strength, as well as when increasing muscle mass, performing long and intense training loads.

According to modern scientific data, the most favorable ratio of proteins and fats in the diet of young athletes is 1: 0.8-0.9 (with the exception of winter sports, horseback riding, motorsports, and swimming). The share of vegetable fats should be 25-30% of the total amount of fats, which will ensure optimal content of polyunsaturated fatty acids in the diet. In particular, the contribution of lipolic acid will be 3-4% of the total calorie content.

Carbohydrate metabolism in children and adolescents is characterized by high intensity. At the same time, unlike the body of an adult, the child’s body does not have the ability to quickly mobilize internal carbohydrate resources and maintain the required intensity of carbohydrate metabolism with increasing physical activity. Young athletes, in this regard, are recommended to consume the bulk of carbohydrates (65-70% of the total amount) with food and in the form of polysaccharides (starch), 25-30% should come from simple and easily digestible carbohydrates (sugars, fructose, glucose) and 5% for dietary fiber.
The need for minerals, and especially for potassium, magnesium, calcium, phosphorus, and iron, among young athletes is significantly higher than that of their peers. Using biochemical control methods, it was established that at the age of 11-16 years, about 26-29% of young athletes have reduced levels of ferrostatus. This indicates the occurrence of initial forms of iron deficiency conditions. Insufficient iron supply is especially common among 15-16 year old athletes. This age marks the middle of puberty, when significant changes occur in the structure and functions of the nervous, endocrine and other systems. Therefore, the body of a young athlete is most susceptible to various negative influences, especially against the background of a high level of physical activity. Iron deficiency anemia various shapes require a diet consisting of a combination of lean meat foods with vegetables and fruits.

In addition, examinations of young athletes have shown that they have a deficiency of vitamins, which perform an extremely important function in ensuring the stability and intensity of metabolic processes. Typically, deviations in vitamin supply are associated with a lack of vegetables, fruits, and berries in the diet. Including vegetables (300-400 g per day), fruits, berries, juices (500 g per day) in the diet allows you to eliminate vitamin deficiency. However, the increased need of young athletes for vitamins cannot always be satisfied through diets, especially in winter and spring, as well as during periods of very intense training or competition. In these cases, additional fortification, preferably complex, should be carried out in strict accordance with the instructions given in the appendix. It should be remembered that long-term overdose of vitamins leads to hypervitaminization and other negative consequences. In accordance with the recommended standards, approximate sets of products are compiled that should be guided by when organizing a balanced diet for young athletes (Table 16). The principles of nutrition for adult and young athletes during competitions are almost the same.

It is possible and desirable to use PPBC in the nutrition of children and adolescents involved in sports. However, it should be emphasized that the contribution of PPBCs to the total caloric intake of the diet should not exceed 5-10%, and their use in large quantities should not be long-term.

As for the diet, a high frequency of meals is recommended for young athletes (5-6 times a day), including taking PPBC. It is important to correctly combine increased physical and nutritional activity. Children should not come to training hungry. After training, meals must be organized so that there is not a large gap in time between training and the subsequent meal.

The traditional distribution of food by meals (and % of total calories) for young athletes is as follows: breakfast - 25-30%, lunch - 35%, afternoon snack - 5-10%, dinner - 25%. A fifth meal is possible (depending on the training regimen) - this can be either a second breakfast (5-10%), or a second dinner (5%) and kefir before bed.

The physical performance of young athletes largely depends on the compliance of actual nutrition physiological needs body. Only a combination of a rationally planned educational and training process and an adequately balanced diet can ensure the achievement of high sports results.

NUTRITION FOR AN AMATEUR ATHLETE OR A PETIZER

Previous chapters discussed the nutrition of professional athletes or young athletes who are preparing to become professionals. However, much more people goes in for sports in order to improve health, increase the level of performance and active longevity. In Russia, amateur athletes are often called physical culturists. A reader involved in physical education with a health-improving orientation should know not only how to properly organize his motor regimen, but also how to eat rationally.

Common nutritional mistakes among people involved in mass physical education.

Analysis of diets from the standpoint of the theory of balanced nutrition helped to identify the most common mistakes in nutrition among those involved in mass physical culture.

The main mistake is the violation of the optimal ratio between the main components of food: proteins, fats, carbohydrates. Most often, they are overly addicted to high-calorie and highly refined foods - sources of fats and carbohydrates. They consume excess fats of animal origin (butter and melted butter, sour cream, fatty sausages, etc.), which ultimately leads to a deficiency of such an essential component as unsaturated fatty acids.

The diets of those engaged in mass physical culture contain an abundance of pastries, pastries, pies, and all kinds of sweets. cold drinks, sugar, cookies, sweets, ice cream, etc. In most cases, only white bread is used, and the consumption of cereals and baked goods made from wholemeal flour is extremely limited. In addition, there is insufficient consumption of vegetables, fruits, herbs, berries, juices, which, in turn, leads to poor nutritional balance in mineral and vitamin composition, to the body’s lack of dietary fiber and many biologically active substances. The extremely narrow, monotonous range of products used in nutrition also attracts attention. All this indicates a low level of nutritional culture.

Thus, summarizing what has been said, we can identify two nutritional disorders in those engaged in mass physical culture - an obvious imbalance of the diet, on the one hand, and its excess calorie content, on the other.

But this is not the end of the mistakes in the nutrition of amateur athletes. Often the diet is not regulated; food is taken only 2-3 times a day, usually with a large intake in the evening. This, even with adequate energy value of the diet, has a negative impact on health.

The mentioned errors largely contribute to the emergence of a variety of diseases, in particular, the current worldwide trend towards an increase in the number of people with overweight and obesity. According to experts, in Russia about 50% of the population is overweight, and approximately one in four is obese. This problem is all the more relevant because there is an undoubted connection between obesity and the early development of atherosclerosis, hypertension and gallstone diseases, and diabetes mellitus. Excessive consumption of fried meat, fish, mushroom main courses, strong meat broths, spicy and salty snacks leads to widespread serious diseases of the digestive system. Nitrogen-containing extractive substances and purine bases of improperly prepared meat, fish, and mushroom dishes make it difficult to prevent and treat many diseases of the kidneys, heart, pancreas, liver and biliary tract.

Without delving into the medical aspects of this issue, we can confidently say that obesity, as a rule, is associated with low physical activity, and only the combined effect of diet therapy and mass physical education can become an effective measure for correcting body weight, since metabolic changes in the body in this case are more pronounced than with the separate influence of each of these factors. The practice of using a low-calorie diet gives good results. In this case, the energy deficit should not exceed the level above which protein metabolism may be disrupted.

So-called “empty” calories should be gradually (over several months) removed from the diet: sugar and sweets, some confectionery and bakery products made from premium flour, visible fat in meat and meat products. However, it must be remembered that incorrect composition of the diet, for example, refusal of bread, cereals, butter and vegetable oil, etc., leads to a deficiency of many extremely necessary food components - B vitamins, polyunsaturated acids, fat-soluble vitamins A, E, D, as well as magnesium. Before switching to a low-calorie diet, you should seek advice from a nutritionist. General rules therapeutic nutrition for overweight and obesity were proposed by the Institute of Nutrition of the Academy of Medical Sciences.

They are as follows:

Low-calorie diet;
- limiting the consumption of sugar, glucose and animal fats (by increasing vegetable fats);
- creating a feeling of satiety with the help of low-calorie, but large-volume food ( raw vegetables, fruits);
- increasing the frequency of meals (up to 6 times a day), which eliminates the feeling of hunger without increasing the amount of food and energy;
- normalization of water-salt metabolism by limiting salt consumption to 3 fluids up to 1-1.5 liters per day;
- use of contrasting and fasting diets.

It should be borne in mind that, for example, in patients with diabetes, regular exercise of a predominantly aerobic nature leads to a decrease in sugar and blood sugar levels with a decrease in insulin concentration, and in atherosclerosis - to favorable changes in the lipid spectrum of the blood. However, even in these cases, a combination of mass physical education and a rational, balanced diet in accordance with the recommendations of a nutritionist has a more effective effect.

Vitamin deficiency, as well as hidden iron deficiency conditions, the occurrence of which is caused in most cases by the nutritional errors listed below, are quite widespread. It is known that they negatively affect human health, the level of physical performance, resistance to colds and infectious diseases, aggravate the course of any disease, and increase the negative impact of harmful working conditions and the external environment. As numerous surveys of production teams have shown, among workers with an insufficient supply of vitamins to the body, muscle endurance decreased by 17-26% after just two hours of work, and by 22-33% by the end of the working day. After additional fortification, muscle endurance remained at the initial level during the first hours of work, but by the end of the day it decreased by only 8-10%. It has been experimentally established that with increased physical activity, the body's need for vitamins increases. However, not only hypovitaminosis conditions are dangerous, but also hypervitaminosis that occurs in case of prolonged overdose. Uncontrolled use of vitamin preparations, leading to oversaturation of the body with vitamins, can lead to serious metabolic disorders.

In order to avoid significant deviations in the vitamin status of those involved in mass physical culture, in addition to rationalization of nutrition, it is certainly necessary to carry out additional vitamin supplementation in winter and spring.

There is a direct connection between the level of iron supply in the body and the level of physical performance; it is due to the importance of iron for erythropoiesis, oxygen transport in the blood and muscles, tissue respiration and oxidative phosphorylation. In those engaged in mass physical culture, as well as in athletes, adaptation to systematic loads, especially of an aerobic nature, may be accompanied by disturbances in iron metabolism, which entails the development of iron deficiency conditions (more often in women). A diet enriched with iron helps eliminate iron deficiency. meat products, vegetables, herbs, fruits. Along with this, it is necessary to rationally use vegetables as a side dish for meat dishes and ascorbic acid, which effectively affects the absorption of iron.

Basic nutrition standards

In the program for improving the health of the population with the help of mass physical culture, the closest attention should be paid to nutrition issues, since the transition to a new motor mode against the background of inadequate nutrition can contribute to the development or deepening of conditions of nutritional deficiency.

Mass physical culture is practiced by people of different professions, ages, genders, healthy people and those with health problems. Medical control allows you to assess the functional state of the body, determine contraindications, and select the appropriate mode and nature of physical activity. Only after receiving appropriate recommendations can those involved in health-improving physical education proceed directly to the formation of adequate diets. First, you should decide on the quantitative characteristics of diets, i.e., make a preliminary assessment of the body’s need for energy and basic nutrients. These data have been widely published (see list of references, Nos. 3, 4, 12). It contains basic nutritional standards, “in particular, the need for energy, proteins, fats, carbohydrates and vitamins, calculated for a statistically average person (men with a body weight of 65 kg, women - 55 kg). These standards were developed for the Russian population by the Institute of Nutrition of the Academy of Medical Sciences, taking into account the intensity of work in different age groups.
With increased physical activity, those involved in mass physical culture can calculate their energy consumption using the data given in this table. Having determined the additional energy expenditures during physical exercise, you should, using the table, sum them up with the main energy expenditures and thus obtain a fairly specific idea of the energy expended per day.

Calculation example: a teacher (age 35 years old, body weight about 70 kg), daily walking for 1 hour at a speed of 8 km/h (see Table 10), spent 450 kcal (7.5 kcal/min x 60 min), therefore, in total the day is 3350 kcal (2900+450)

Of course, in practice it is impossible to take into account the exact number of calories, since the tabular method gives a discrepancy between 200 and 500 kcal, so we must remember that the calculation uses average statistical currents.

Energy expenditure can be more accurately assessed by timing activities over three to four days, including one day off. To do this, you can use the method developed by Canadian scientists. It consists of self-registration of individual levels of motor activity (there are 9 in total), dominant in every 15 minutes of every hour of the day. The recording is made in special physical activity cards in the form of digital codes corresponding to certain activity levels. The energy characteristics of the latter are expressed in kcal/kg body weight 15 min. A typical sample of a completed registration card is presented in table. 17.

Calculation example (body weight = 70 kg):

1) 34x0.26x70= 618.8
2) 32x0.38x70= 851.2
3) 10x0.57x70= 399.0
4) 12x0.69x70= 579.6
5) 2x0.84x70= 117.6
6) 4x1.20x70=336.0
7) 1x1.40x70= 98.0
8) 1x1.50x70= 105.0

Daily energy consumption = 3105.2 kcal

PROPAGANDA AND ORGANIZATION OF RATIONAL NUTRITION IN A SPORTS CLUB (BY THE EXAMPLE OF BODYBUILDING)

Let's start with simple examples and situations. A beginner who joins a sports club for the first time and a coach need to understand that systematic physical exercise itself, time and organization of classes, new emotional impressions are all factors that will have to get used to (adapt) by changing the usual lifestyle.

It is interesting that the Greek word “diet,” as already said, is translated into Russian, first of all, as “way of life.” So, our newcomer has a new way of life. In this case, you first need to analyze the usual nutritional patterns (regime and diet), since, as is known, a significant part of the population has typical nutritional errors, which have recently been aggravated by well-known problems of the family budget.

Unfortunately, some minors and adult “beginners” are already well acquainted with pharmacology (anabolic steroids, “chemistry”, etc.) but poorly with proper nutrition. Against the background of inadequate nutrition, a new lifestyle and, above all, physical activity can lead to negative results: frequent injuries, illnesses, nervous-emotional stress, and refusal to exercise. Often a beginner tries to force the load, to try his best in training, which also ends in failure. Therefore, the first requirement for nutrition is the urgent identification and correction of typical errors and deviations from general recommendations for a healthy diet.

For this purpose, a trainer or doctor suggests that students keep a diary for several days (5-7 days), which indicates the time of meals, dishes and products, their quantity and in the notes information about additional intake of vitamins and other nutritional supplements.

When analyzing your diary, you need to pay attention to the total number of foods consumed, even in small quantities. It would be nice to count 20 or more items. Next, you should determine the assortment of greens, vegetables, roots, herbs, fruits and berries. 10 different items are recommended. Then determine the presence of dairy products and sources of complete protein in the diet; must be fresh vegetable oil, bread, potatoes and cereals. For example, Appendix 1 to this book provides typical diets and methods for compiling them. If the analysis of the diary shows noticeable discrepancies with the given recommendations, then they need to be eliminated as quickly as possible. When analyzing, it is easy to see problems with diet. It is very important to understand that for most beginners, especially young people under 21, the most appropriate diet would be 4-5 meals a day.

The second requirement is the presence in the club of popular science literature, or the so-called visual propaganda on rational nutrition, based on the official recommendations of the Ministry of Health and the Institute of Nutrition of the Russian Academy of Medical Sciences. First of all, you need to know and promote this knowledge about nutrition, and only then the student can experiment with his health at his own discretion.

The third requirement is that the athlete must keep a food diary and analyze it constantly or periodically. Practice shows that for some beginners, enthusiasm and serious motivation quickly end, and they return to their usual diet. Proper nutrition is accessible only to an organized person. A new lifestyle requires new conscious and sustainable eating habits.

The fourth requirement is that as you get used to the level and intensity of the loads, they naturally increase. Consequently, the quantitative indicators of nutrition must also change. But how? And what is written down is from the students’ own goals and objectives.

For women and some men, the number one goal is to remove excess fat and make a slimmer figure. If the goal is achieved, the amount of poverty can be left the same; if not, then you should continue to slowly reduce the total calorie content while maintaining a balance in the main indicators of nutrition and chemical composition diet.

When it comes to developing muscle mass and strength (bodybuilding), it is necessary, on the contrary, to increase the content of carbohydrates and proteins in the diet gradually, as the frequency of training, its duration and intensity increases. It can be assumed that 4-5 workouts per week for 60-90 minutes will require an increase in the amount of protein to 2-2.3 g per kg of body weight, simple and complex carbohydrates - up to 7-8 g per kg of body weight and fat - 1. 5 g per kg body weight. This is the usual norm for a beginner’s training program in the 4-8th month of bodybuilding.

The fifth requirement is that the use of special nutrition in the form of PPBC, dietary supplements, fat burners, anabolizers (but not anabolic steroids!), etc. is permissible only against the background of proper balanced nutrition. No special mixtures should displace natural, familiar foods from an athlete’s diet. All PPBC may account for only 15-20% of the total energy of the diet (25% is the maximum).

According to theoretical calculations, a person needs several thousand organic compounds from food every day, but science has so far identified only 600 of them. Therefore, all spells and statements that such and such a powder, capsule or pill contains a complete set necessary for the body nutrients are absurd to say the least. Therefore, the abuse of supplements leads to more problems than is commonly believed.

ABOUT SOME CONTROVERSIAL ISSUES IN THE SCIENCE OF NUTRITION IN ATHLETS

Recently, the attention of specialists in the field of nutrition of athletes has been attracted by the latest achievements of fundamental sciences, such as biochemistry and physiology, which reveal the subtle mechanisms of adaptation of the human body to systematic muscular activity.

First of all, new data on the causes of general (central) and muscle fatigue (refusal to work) and the possibility of correcting metabolic processes using nutritional factors are interesting. In particular, the issue concerning some essential amino acids, including tryptophan and the so-called branched amino acids (BAA) - leucine, isoleucine and valine, is widely discussed. The fact is that the level of free tryptophan and the ratio of the concentrations of tryptophan and CAR in the blood affects sleep :) and the content of serotonin in the brain, and serotonin plays a key role in the formation of general, or central fatigue.

It is known that tryptophan is found in the blood bound to the protein albumin, but some tryptophan is also found in a free state. It is in this form that it is transported to the brain, but the mechanism of transfer of tryptophan from the blood to the brain is very specific, and not only the presence of free CAR is important, but also the relationship between the content of free tryptophan and CAR. It has been established that the higher this ratio, the more serotonin can be synthesized and found. This situation is observed during prolonged physical activity, when free PAKs are intensively oxidized in working muscles, which means their level drops, and in parallel with this, there is an increase in the level of free fatty acids, which free tryptophan from binding with the transporter protein albumin.

This circumstance served as the basis for the emergence of a pirinoro kind of speculation about the directional regulation of the ratio of free tryptophan to cancer using nutritional supplements and the direct effect on the delay in the development of symptoms and general or central fatigue syndrome in athletes) in cyclic sports.

Great care should be taken when using so-called medium-chain triglycerides (MCTs) in the nutrition of athletes.

CT is a semi-synthetic mixture of fats, which is obtained from natural triglyceride fats. Conventional triglycerides are esters of glycerol and saturated long-chain (12 or more carbon atoms) fatty acids - LCFA. In ST the latter are replaced by saturated fatty acids with medium length carbon chain (6, 8, 10 carbon atoms) - MCFA.

Specific characteristics of ST and MCFA that may be important in an athlete’s nutrition:

Liquid consistency and better miscibility with water;
- rapid digestibility of ST and absorption in the intestines;
- direct entry of MCFAs into the liver through the bloodstream (LCFAs first enter the lymphatic system);
- favorable transport form in the blood - in connection with albumin or in the form of chylomicrons, as well as direct entry into mitochondria without the participation of an intermediary - carnitine;
- 1 gram of ST contains 8.4 kcal of energy.

All this indicates that CT and MCFAs oxidize and supply energy faster than regular fats and could have a better sparing effect on muscle and liver glycogen in the body during aerobic and mixed modes of physical activity.

However, the first practical results of using ST in sports are contradictory and do not give an exact answer to the question about the possibility of increasing sports performance with additional use of ST. Moreover, it has been shown that with a one-time consumption of 30 g of ST, stomach upsets are observed, which gradually disappear with systematic adaptation to the intake of ST.

Questions and answers

Numerous issues of theoretical and practical significance are constantly in the field of view of leading scientists and specialists in sports science. The following is an excerpt from a round table discussion that took place with the participation of nutrition, physiology and medicine experts from the International Federation of Sports Medicine at the World Conference in Greece in 1997.

The opinion of sports nutrition experts sometimes does not coincide with popular belief.
Question. L-carnitine is recommended as a means of improving fat metabolism and athletic endurance, as well as promoting fat burning. How do you feel about this?

Answer. Very little scientific evidence suggests this. From the point of view of Professor Ed Coyle, carnitine in this sense is a waste of time and money.

Carnitine is involved in the transport of fatty acids to mitochondria, where the process of fat oxidation occurs. This process takes place through the mediation of an enzyme that binds fatty acids to carnitine. However, the activity of this enzyme (palmitoyltransferase) and fat burning function are not affected by dietary supplements containing carnitine. There are several studies that support this point of view. For example, Dr. Vukovic and Dr. Costil found that mitochondria contain enough carnitine to support fat burning during exercise. Further, Dr. Trappe and Dr. Costeel reported that supplementation containing L-carnitine did not provide an ergogenic effect during repeated high-intensity aerobic exercise in well-trained swimmers. These claims are backed by a large amount of research.

Question. There is ample evidence that long-distance runners need extra protein to perform well. What about endurance sports?
Answer from Professor Saris.

The main source of nutrition to satisfy energy needs is carbohydrates and lipids. The use of protein (protein) or amino acids only makes sense when the energy provided by ia counting lines and carbohydrates does not meet the body's energy needs. Moreover, dietary proteins, and especially amino acids, are necessary to replace muscle proteins that are broken down after muscle injuries caused by training, especially when the training is extreme.

It is well known that protein requirements range from approximately O.K to 1.0 g per kilogram of body weight per day for sedentary individuals. Some studies conducted by different laboratories using either the nitrogen balance method or the metabolic tracer technique (radioactive tracer) have found that the recommended intake for trained athletes should be 1.6 to 1.7 times that of inactive people, which is approximately 1 .4 to 1.6 g per kilogram of body weight. Increasing the rate will not be beneficial and may be considered less than optimal, as it will increase the nitrogen load on the body and lead to the production of excess urea. Moreover, it will negatively affect the consumption of fats and carbohydrates. The following arises important problem: Is the recommended daily intake of protein in a normal daily diet sufficient for trained athletes without the inclusion of additional drugs. Some research in this area suggests that it is sufficient. At the same time, the energy consumption figure is approaching 15%. Since energy requirements, and therefore energy consumption, are quite high, the absolute level of protein intake is approximately 1.4 g per kilogram of body weight per day or slightly higher. Thus, we can conclude that trained athletes need a higher daily protein intake than ordinary people who do not engage in sports. However, based on the concept of adequate sports nutrition, the protein intake from food is more than enough, which removes all scientifically based arguments in favor of taking protein supplements.

Question. It is believed that arginine and ornithine improve the secretion of growth hormones. Is it so?

Answer from Professor Kuypers.

In clinical medicine, there are cases of using intravenous solutions of arginine and ornithine when testing the reserve of growth hormones in humans. Moreover, based on the minimum amount of amino acid required for the body (250 mg/kg), their dose is 15-30 g.

Other amino acids may also lead to temporary secretion of growth hormones. Based on this, highly trained athletes promote the use of arginine and ornithine. However, in the case of oral administration, the body absorbs a significantly smaller amount of both, making the effect very questionable. Research by Vogelholm, Lambert and Suminski (1993) showed that there was no effect on the secretion of growth hormones and insulin by taking arginine, lysine, ornithine and tyrosine, taken alone or in combination. The few studies supporting the effect have been questioned due to insufficient statistical data and methodological flaws. Thus, oral administration of these amino acids does not lead to the secretion of growth hormones, and even if this effect were detected, it would be temporary and would not affect athletic performance. My advice to athletes is very simple: there is no scientific basis to believe that oral arginine and ornithine supplements have a beneficial effect on athletic performance, and the use of such products is a waste of money.

Question. Over the past three years, significant attention has been paid to 30-30-40 nutrition, also called “zone nutrition,” as a method of improving adaptation to training and athletic performance itself. The rationale for this method is not scientific. What is your opinion?

Dr. Hawley's response.

“Zone Eating” was developed and made popular by Dr. Berry Sears and his book, “Get in the Zone.” This book declares that the zone of optimal health, weight maintenance and successful sports form can be achieved by following the nutritional system he developed. The point of the system is the ideal balance between insulin and glucagon levels. This is achieved by consuming a food energy mix (mixture) consisting of 40% carbohydrates, 30% fat and 30% protein. In practice, it looks like this: food is divided into “good” carbohydrate blocks (low glycemic index), protein blocks and fat blocks, which are consumed during the day in a certain ratio. However, food does not consist of ideal blocks, and the recommended food mixture is hardly realistic in the context of a generally accepted daily diet, which includes normal, ordinary foods. The book is contradictory, the recommendations are not practical, and many of the facts given are misleading. The book contains a lot of loud statements related to the healing effect of the method, etc. Quotes and examples used in the book are selective and often anecdotal; in short, all statements do not have a worthy basis.

Question. Chromium, especially in the form of chromium picolinate, is recommended as an effective means of reducing body fat and increasing muscle mass. On the other hand, a recent article in the journal Sports Nutrition criticizes this point of view. What is your opinion?

Professor Maughan's response.

Chromium is a good example of a dietary supplement offered to athletes. There is a kernel of scientific truth in the method mentioned, but the truth is viewed out of context and is greatly exaggerated. The enthusiasm is based mainly on three arguments.

1. It is believed that chromium may potentially contribute to the anabolic effect of insulin, which in turn could potentially lead to increased muscle tissue. However, these results were obtained using isolated cells and were not confirmed in studies of the whole organism.

2. There is evidence that most of of the population (perhaps 50 to 90%) does not consume the recommended daily dose of chromium. This statement does not take into account the fact that errors in estimating the daily intake norm can be significant, and the norm itself may be questioned. There is no scientifically documented data on the widespread symptoms of chromium deficiency.

3. Exercise can cause your body to lose more chromium. This is the reason why athletes believe that they need additional chromium supplementation. However, an increased daily diet, which is necessary to meet the increased needs of the body and energy, will provide additional chromium if this diet is sufficiently varied.

At least two published studies claim that nutritional supplements containing chromium picolinate (a complex of chromium with picolinic acid, which increases the absorption of chromium), during short-term (6-12 weeks) weight training can increase lean body mass and reduce the fat component. It is believed that chromium provides an increase in muscle strength. However, what is considered the best study does not show evidence that chromium supplements changed body composition or increased muscle strength in football players during the pre-season. In conclusion, there is some evidence that chromium deficiency is a problem among athletes. Evidence for the beneficial effects of chromium supplementation on body composition and muscle strength is inconclusive.

Question. During endurance training, athletes often consume bananas, which are considered an excellent source of potassium and magnesium. Is this true?

Bananas are not a miracle. It is a good source of carbohydrates for endurance training. However, you should know that unripe and semi-ripe bananas do not contain much starch, which is absorbed by the body. The starch found in unripe bananas is called resistant starch, meaning that it is poorly digested by the enzymes in the digestive tract that normally break down starch into glucose.

The fact that the nutritional value of starch increases in ripe bananas is due to the presence of enzymes in the banana itself. As bananas ripen, these enzymes break down resistant starch into highly digestible sugars. Compared to other sources of carbohydrates, bananas are not a great source of magnesium and potassium; potatoes, for example, contain 443 mg of potassium and 25 mg of magnesium, while bananas contain 393 and 36 mg of these elements respectively per 100 g of product.

Question. Cyclists often take glucose or saline at night to aid recovery. Is this good or bad?

Dr. McConnell's response.

These solutions contain salt and sometimes some glucose. Taking a glucose solution at night orally or intravenously is an attempt to speed up the process of muscle glycogen resynthesis. However, glycogen levels three hours after exercise do not depend on the form in which glucose enters the body - in the form of an intravenous solution or with food. Thus, the use of a glucose solution does not make much sense, except in cases where athletes have digestive problems that reduce the ability to absorb foods and solutions. Athletes are also concerned that glycogen resynthesis will not be maintained at night. However, this can be offset by taking about 200 g of carbohydrates before bed (the amount - 200 g - is determined based on the breakdown rate of 25 g per hour and 8 hours of sleep). This can be provided by 1 liter of 20% sports drink, or better yet, a combination of the two drinks.

Athletes also like to use salt solutions after dehydrating workouts, believing that the restoration of water balance will be more complete when the solutions are administered intravenously than when taken orally. However, a recent study found that oral administration of solutions during a 2-hour recovery period after a dehydrating workout in the heat resulted in decreased thirst and stress levels during subsequent exercise compared to intravenous administration of the same amount of solution. In addition, body temperature, sweat rate, and quality of athletic performance were similar in both trials. Fluid intake can lead to rapid and complete post-workout rehydration (restoration of water balance). And although intravenous infusions seem somewhat exotic, they require medical intervention, are more expensive compared to the digestive process, and limit movement while falling asleep.

Question. Some alkaline drinks are thought to help reduce the acid load on the body during intense exercise, e.g. mineral water and sports drinks. However, these products contain a minimal amount of buffer. Are the mentioned properties of these drinks confirmed?

Dr. Greenhuff's response.

These claims are erroneous and hardly based on real data. Studies demonstrating the effects of taking alkaline equivalents (alkali metal cations) during exercise have been conducted at levels of 1 g of supplementation. For example, 0.3 g sodium bicarbonate per kilogram of body weight (21 g for a 70 kg body weight) was consumed approximately 3 hours before exercise. This dose, as shown by repeated experiments, produces significant changes in the pre-workout acid-base balance and in the process of lactate accumulation in the blood after exercise. It should also be noted that studies examining the effects of alkaline equivalent supplementation on performance or training performance have been mixed, demonstrating significant differences in acid-base balance. This is a result of the fact that taking alkaline equivalents is not always associated with improved performance.

Question. Recently, it is believed that the use of colostrum is an effective means for improving training adaptation mechanisms, which is associated with the high content of colostrum in growth factors. What is colostrum, and is there evidence of benefits from taking colostrum supplements?

Dr. Kaiser's response.

The first milk after birth is called colostrum or colostrum. Colostrum contains a whole range of complete bioactive peptides, growth factors and immunoglobulins. In sports medicine, there is a hypothesis that colostrum may help prevent muscle damage or speed up recovery (protein synthesis) after a very strenuous workout. Indeed, using the example of newborn animals, it was shown that colostrum has a positive effect on protein synthesis of skeletal muscles, increases the concentration of liver glycogen and reduces the content of cortisol (catabolic hormone) and blood plasma. Ballard and Francis convincingly demonstrated that colostrum has an anabolic effect on developing muscle cells in vitro, unlike anabolic steroids. Most recently, we did a double placebo crossover study in which runners had to train on their best days. Scientists did not find any positive effects of colostrum on running performance, recovery time, or parameters of muscle fatigue (i.e. muscle enzymes and proteins). Thus, there is no scientific data on the benefits of colostrum for athletes.

Question. Recently, athletes have been recommended to additionally take the amino acid glutamine as a means of strengthening the immune system. This should lead to a reduction in colds and infections. Is this recommendation supported by scientific evidence?

Answer from Professor Wagenmakers.

The intensity of glutamine synthesis in muscles is higher than that of any other amino acid. The significance of such a high level of glutamine production may lie in the role of glutamine in other organs, as a means of feeding cells of the immune system, cells of the intestinal mucosa, as a precursor for urea synthesis and a participant in purine biosynthesis. Low levels of glutamine in muscle and plasma are observed in patients with septic conditions and trauma, conditions in which mucosal atrophy, loss of intestinal barrier function (bacterial translocation) and weakened immune response occur. Although the relationship between the decrease in glutamine concentration and the loss of these functions was not fully investigated during the experiment, it can be assumed that such a relationship is temporary. During exercise, plasma glutamine concentrations may increase, decrease, or remain unchanged, depending on the intensity and duration of the exercise. However increased level plasma glutamine levels are observed for several hours after intense exercise. The lowest level of concentration occurs approximately 2 hours after exercise. It takes more than 7 hours for glutamine concentrations to return to pre-workout resting levels. Parry-Billings et al observed a decrease in plasma glutamine concentrations in 40 international athletes diagnosed with overtraining compared with the same levels in 36 control athletes.

There is an opinion that athletes often develop viral infectious diseases of the upper respiratory tract after long and intense training. Overtrained athletes experience significant damage to their immune systems, making them even more susceptible to infection. Parry-Billings and colleagues hypothesized that the decrease in plasma glutamine levels after intense exercise creates a temporary “open window” period during which athletes are more susceptible to viral infection than usual.

Castel et al gave supplemental glutamine or placebo immediately after exercise and two hours later to marathon or ultra-marathon athletes who had lower levels viral diseases in the glutamine group, within a week after the race. The level of infection was determined by questionnaire. All symptoms recorded by study participants in the words: “cold”, “cough”, “sore throat”, “influenza” and observed within a week after the race or training were considered as a manifestation of infection. Before concluding that decreased plasma glutamine concentrations are associated with immune system damage in overtrained athletes following intense exercise and that glutamine supplementation reduces infectious disease rates, more robust and objective data, supported by better evidence, are needed. fundamental research immune system.

Question.“New age drinks,” also known as “designer drinks” or “brain products,” are becoming increasingly popular. These drinks contain relatively high doses of caffeine, taurine and glucoronolactone. These drinks are believed to improve brain function and physical performance. Are they recommended for athletes?

Answer from Professor F. Brauns.

These drinks have a fairly high content of caffeine and carbohydrates. Most contain high levels of an amino acid (thiurine) and other substances such as glucoronolactone. Caffeine is known to improve motor activity in doses of 3-5 mg/kg body weight, which is equal to the consumption of one liter of drink containing 320 mg/liter of caffeine. At this level of consumption, the doping limit (12 mg/liter and urine) is not exceeded, as evidenced by Pasman et al. (1993). However, consuming larger amounts of a highly caffeinated beverage may be risky until the effects of high doses of caffeine on caffeine levels in urine are studied. Trained athletes should be aware that such drinks are especially not recommended for consumption during training. Typically, the carbohydrate content of these drinks and their osmolarity are too high to ensure rapid absorption. Therefore, they can cause gastrointestinal discomfort. As for taurine and glucoronolactone, it remains to be seen whether these substances have a positive effect on the physical activity of people. Taurine is involved in many regulatory functions of the body, among which is the regulation of the fluid content of the cells of the central nervous system. Glucoronolactone is produced by the body and is a byproduct of carbohydrate metabolism, playing an important role in detoxification of the body. There is no scientific evidence that oral glucoronolactone has a beneficial effect on health and physical activity. The effects of these dietary supplements on athletes have not been studied.

Dr. McConnell's response.

It is important to consume enough carbohydrates and fluids after training to ensure optimal recovery for competition the next day. The maximum level of muscle glycogen resynthesis is achieved with carbohydrate intake at a rate of 25 g per hour (approximately 600 g in 24 hours). At this rate of consumption, muscle glycogen is completely restored in approximately 20 hours. Consuming large amounts will not increase glycogen resynthesis levels. 50 to 100 g of carbohydrates and liquid or in easily soluble solid form should be taken immediately after training if possible. Delaying the consumption of carbohydrates for 2 hours after exercise has a minor effect on glycogen resynthesis, but only if a large amount of carbohydrates was later consumed to compensate for this delay. It is necessary to consume more foods with a moderate to high glycemic index (bread, rice, potatoes, ripe bananas, sports drinks) because they accelerate the resynthesis of muscle glycogen more reliably than foods with a low to moderate glycemic index (see page 27). It is also necessary to optimize fluid replacement after exercise. The amount and composition of fluid absorbed is important for optimizing rehydration processes. If regular water is absorbed during the recovery period at such a rate to compensate for the amount of fluid lost (during exercise), then not all the fluid is retained in the body. This happens because water thins the blood, which in turn stimulates urine production. However, if drinks have added electrolytes, especially those containing sodium cations, or if food containing electrolytes is taken with water, most of the absorbed fluid is retained in the body. In order to restore fluid balance after exercise, you need to consume about 150% of the volume of fluid lost (mainly in the form of sweat) during exercise. And the liquid must contain sodium. The optimal sodium content in the drink for water retention is 50-100 mmol per liter. Since a solution containing sodium at a concentration of 100 mmol per liter has a rather salty taste, at one time it was suggested that solutions containing 50 mmol/l of soda should be drunk. It is recommended to limit the consumption of caffeine and alcoholic beverages immediately after exercise, as both of these substances can increase urine production.

Any illegal copying of information will be prosecuted and protected in accordance with the laws of Russia, Ukraine, and Belarus.

When quoting the content of a website on the Internet (regardless of the type of materials) active link to the portal is required. For other types of use of materials, conditions are negotiated separately.