Medicine : Athletes Nutrition
Basic principles of rational nutrition of athletes
1. Power consumption of the organism and its dependence on the work performed
Nutrition and to respect the energy balance in the body according to the following principle: the amount of energy that came must meet the quantity of energy consumed.
The energy in the human body comes from food in the form of carbohydrates, fats and proteins. In the cells of the body in the process of their chemical transformations of energy comes out and uses for different purposes. As you know, when oxidation of 1 g carbohydrate, as well as proteins released 4 kcal (17 kJ) and fat - 9 kcal (37 kJ) of energy. Knowing the chemical composition of foods and their calories that are listed in a table, you can calculate the calorie content of any menu or diet. Certainly caloric or energy value of food is expressed in kilokaloriyah 100 g of the product or the recommended dose.
Caloric content of daily human diet varies depending on the amount of energy that a person consumes. In short insufficient receipt of energy (food calories) the body spends spare substances, mainly fats and complex carbohydrates, while the long - are used not only fats and carbohydrates but also proteins, which leads to a reduction in body weight, atrophy of m 'muscles, anemia, growth retardation, decreased physical performance. When surplus energy flow decreases its utilization, because of carbohydrate and fat in tissue is delayed as fat, which can lead to obesity.
Daily energy consumption of the human body include the main exchange (the minimum amount of energy needed to maintain basic body functions and processes of biosynthesis in a state of relative calm), specific-dynamic action of food or energy costs in the digestion and absorption of food (mixed diet - on average 10-15 % of daily energy expenditure) and energy costs for various activities.
Basal metabolism depends on age, sex, body weight, external conditions, individual characteristics of a person and an average of adult men weighing 65 kg - 1600-1800 kcal and for women weighing 55 kg 1300-1400 kcal. In counting children for the basic unit of body mass exchange in 1.5 times higher than in adults, and elderly - are lower than in adults.
Specifically, dynamic action of food can have different energy costs depending on the content of food proteins, carbohydrates and fats. The largest consumption of energy occurs when digesting proteins (up to 30-40%). For fat, he is 4-14% and for carbohydrates - 4-7%. Even a cup of liquid increases the basal metabolism by about 8%. Balanced flow of certain components of food observed increase in basal metabolism on average by 10-15%.
During the various activities, especially m 'muscle activity, significantly increasing energy consumption rights. Yes, if you read the book only increases the basal metabolism by 16%, the exercises - several times more. Total energy consumption and calorie diet for the population determined according to the dietary rules that encourage the World Health Organization 's (WHO). However, in many countries they have their own characteristics, so that taking into account various parameters: age, weight, basal metabolism, activity and other factors. Average daily energy consumption by men of student age (19-24 years) is 2900 kcal / day, and women the same age - 2200 kcal / day. For people with different body weight and higher physical activity engaged in different fields, energy consumption, depending on the severity of the work can be approximately 2200-2500 kcal / day - men and 1800 - 2200 kcal / day - women engaged intellectual work, then as people engaged in hard physical labor - to 4300 kcal / day in men and 3000 kcal / day - women. Therefore, their food must bear the cost of energy, that is more caloric. However, the continuing prevalence of daily caloric foods over power consumption of 300 kcal (calories 100-gram buns, leads to accumulation of reserve fat within 15-30 g per day, which is about 5-10 kg per year).
Energozatraty athletes of various specializations depending on the intensity of performed physical work, sport and range from 2000 kcal / day for players and gymnasts to 7000 kcal / day for a weightlifter and athlete involved in endurance sports (such as cyclists).
Analysis of the diurnal energy consumption of different sports showed a wide range of differences in consumption between different sports and even within the group of athletes a sport. For the team sports also characterized by high consumption of energy, as its men's basketball players in the flow may be around 5500 kcal / day. The largest consumption of energy observed in cyclic sports athletes where you want a more general endurance.
As seen from the data, energy consumption in athletes is similar to the people who perform heavy physical labor. However, during the performance of the maximum power consumed very large amounts of energy per unit time. Such work is performed in the anaerobic mode (in terms of oxygen debt).
Energy consumption in athletes depends on their sports skills. With the growth of sports skills and energy consumption in the performance of standard work is reduced. The amount of energy consumption also influences the emotional state of the athlete. Yes, peredstartovomu condition or during competitions energy costs in carrying out equal work increased by 26-29% compared with the training.
Daily energy expenditure of athletes in various sports through enerhonadhodzhennya compensated by carbohydrates, fats and protein foods, as well as stocks of nutrients accumulated in the body before (fatty tissue, glycogen, muscle proteins).
2. Balanced nutrients in the diet of the athlete
Equilibrium income of carbohydrates, fats and proteins. Today found that the most favorable of energy and plastic needs people to achieve a balanced flow in the body of carbohydrates, fats and proteins in the ratio 4:1,2:1. Carbohydrates in this case should be 50-55% fat - 30-35%, protein - 10-15% of total calories diet.
For athletes the ratio of carbohydrates, fats and proteins may vary depending on the specific sport, volume and intensity of work performed and constitute 40-70% of total energy consumption of carbohydrates, 20-42% - and 10-22% fat - protein. General pattern of balanced diet, the athlete is that in endurance sports increases the number of carbohydrates to 55-65-70% of total daily calories by reducing fat to 20-30% and protein - up to 10-12%.
From carbohydrates in the diet most (65%) shall provide complex carbohydrates (polysaccharides). Daily demand of fats in the diet should be provided for 70% of animal fats and 30% - of vegetable origin which contain mono-and polyunsaturated fatty acids. High-grade protein sources are animal products.
Acidity and alkalinity of food. Food products contain a number of acids and alkalis, therefore, can affect the pH balance in the body, zmischayuchy it in acid or alkaline side. Buffer systems that are in the body, oppose this. However, its capabilities are limited, and when m 'muscle activity accumulated acid products of metabolism. It is therefore necessary to limit the receipt of the body acidic food after intense physical exertion in order to prevent acidification enhance the internal environment of an organism athlete.
To zakyslyuyuchyh include bread and other cereals, as well as m 'meat, fish, eggs, and acidity are determined by the reaction of ash foods. On the accumulation of acid and alkaline components in the tissues affect vitamins. Thus, while deficiency of vitamin B1 in the body is limited to oxidation pirovynohradnoyi and other organic acids, which contributes to acidification of internal environment of the body and increases susceptibility to disease.
3. The role of individual chemical components of food to ensure m 'muscle activity
The main chemical components of food are the following six groups of substances: suppliers of energy (carbohydrates, fats, proteins), indispensable amino acids, indispensable fatty acids, vitamins, minerals and water. Each agent performs a specific function in the life of the body and affect the performance of physical work.
The main sources of energy in the tissues of the body are carbohydrates and fats. Fats serve as structural feature. Proteins can be used as energy source, but their primary function-structure. Vitamins are part of many enzymes and are regulators of various metabolic processes. Minerals also perform its regulatory role within the structure of various tissues, especially bone, and blood. Water creates the internal environment of an organism and provides the chemical reactions.
The human body can synthesize and lay down a lot of nutrients, but some are not synthesized in the body. They called the indispensable food and essential factors must come from food. In their insufficient receipts violated many metabolic processes and the adaptation process when m 'muscle activity, may develop the disease.
4. The role of carbohydrates in securing m 'muscle activity
Carbohydrates are one of the most important for human nutrition as a major source of energy for intense m 'muscle activity. From the carbohydrate reserves in m 'muscles and the liver depends on the duration of aerobic physical performance or display of high strength and timing fatigue. Carbohydrate foods provide a certain level of blood glucose, which is the main energy substrate of the brain and the accumulation of glycogen reserves in m 'muscles and liver.
Specifics of certain types of carbohydrates. Carbohydrates are mainly in animal foods (bread, cereals, pasta, potatoes, sugar, fruits and vegetables) in the form of mono-, di-and polysaccharides. Di-and polysaccharides in the food digestion enzymatic hydrolysis and are converted mainly into glucose.
Monosaccharide food represented mainly glucose and fructose, which are containing in many fruits, the media and called sugar. In the body they come in a free form, or formed during digestion of di-and polysaccharides food. Income in the body of a large number of free glucose and its rapid absorption into the blood (already in 15-20 minutes after eating she appears in the blood) leads to an increase in its concentration in the blood, which activates the function of the pancreas, which selects the hormone insulin, which provides income glucose in the tissue where it is used for the synthesis of glycogen, while a significant surplus - for the synthesis of fat. After the action of insulin in the blood glucose level decreases, which can lead to hypoglycemia and general weakness. The systematic activation of the pancreas may contribute to the development of the disease diabetes. Therefore, the number of Monosaccharide feeding people, especially in old age should be limited and not exceed 25 - 35% of the total number of carbohydrates consumed.
Free glucose is used in the clinic for the rapid increase of its concentration in the blood and improve the nutrition of tissues. In sports practice using glucose during physical work as well as in the rest period to accelerate the restoration of glycogen reserves. Use of glucose 1,5 - 3 h before prolonged physical exertion is not recommended, especially during the competition, because it accelerates the exhaustion of reserves of glycogen and suppresses the use of fats. Often, instead of glucose for the accumulation of glycogen in the liver will use fructose. Fructose is absorbed from the slower rate of blood from the gastrointestinal tract and activate the function of the pancreas, but restores glycogen in two times slower than glucose and other carbohydrates.
Disaccharide sucrose represented plant foods - a major component of many food and sugar confectionery (sweets, cakes, jams). When splitting polysaccharides, especially starch, in the digestive system formed disaccharide maltose, which is split into two molecules of glucose. Sucrose splits into glucose and fructose. Simultaneous consumption of a large number of sucrose as Monosaccharide, can cause hyperglycemia, so it is justified only when needed quick recovery of stocks of energy.
In milk and dairy products is disaccharide lactose - milk sugar. This is the main carbohydrate food children the first year of life.
Polysaccharides food represented mainly starch, which is in plant foods (potatoes, cereals, bread, rice, etc..), And glycogen - animal starch. In the human digestive system slowly splits starch into glucose, which is gradually absorbed into the blood, which does not cause a sharp increase of its concentration in the blood. Therefore, the diet should prevail polysaccharides (65%). Glycogen is made from food products in small quantities, about 15 mg / day).
Separate groups of carbohydrates different accessibility of hydrolytic enzymes in the gastrointestinal tract and the rate of flow of glucose in the blood, that affects both glycemic index. There are products with high, medium and low glycemic index, use of which leads to a different increase blood glucose.
Dietary fiber - a plant polysaccharides, which in the body in the process of digestion is not fissile. Treated cellulose (fiber), Hemicellulose and pectin and lignin. They are the gastrointestinal tract intact and is called a ballast substances.
Dietary fiber is not nutrients, but plays an important regulatory role in the digestion of various substances. They intensify promotion of food supply, the formation of intestinal juice, bile, stimulates the withdrawal of cholesterol from the body, slow down absorption of glucose in the large consumption of sugar and called 'yazuyut poisonous substances and take them from the bowel. Permanent arrivals fibers in the human body decreases the probability of disease atherosclerosis, cancer, and improves the function of the gastrointestinal tract. However, excess of their number decreases absorption of minerals (Fe, Ca, Mg, Cu) and liposoluble vitamins. Dietary fiber containing in rye bread, vegetables (cabbage, beets, carrots), fruits (apples, prunes). Rate of consumption - 10-15 g / day.
Consumption of carbohydrates after physical exertion. The daily demand for carbohydrates to adult depends on body and energy at an average of 300-400 g / day.
For athletes norms increase in consumption of carbohydrates called 'connection with the additional energy consumption when performing work. In some sports it flow almost 1,5-2 times more than the people involved in physical labor. Therefore, the need for carbohydrates and increasing at an average of 400-700 g / day. Since the energy consumption depends on body weight and level of physical activity, the amount of carbohydrates needed to fill the energy expended, taking into account these parameters can be calculated, multiplying body weight (kg) by the number of carbohydrates (* g / kg * day), which corresponds to motion activity.
In sports with high-intensity endurance training and the first day after they recommended to consume 10 grams of carbohydrates per 1 kg body weight per day, but in power and power-speed - 7 grams per 1 kg body weight, which is 700 and 490 g day -1 according to the weight 70 kg.
For athletes allowed to increase consumption of simple carbohydrates norms (sugar) to 100 g day-1 and more. For people leading sedentary lifestyles, and in old age consumption of sugar should not exceed 50Ñ€.
Reduced carbohydrate content in food below 300 g increases the dissolution of cell proteins, fat oxidation and formation ketonovyh body that can lead to acidosis. The systematic excess revenues carbohydrate intake can lead to obesity, atherosclerosis, diabetes mellitus, because of the carbohydrate is converted into fat and cholesterol.
Glycogen reserves in kistyakovyh m 'muscles and liver running out 2-3 h after intense exercise, which corresponds to 60-80% of ICN. They can run dry and in a shorter time when using high power within the 90-130% IJC, but restored slowly - 5% per hour. Therefore rest period created conditions for more rapid restoration of glycogen reserves.
The speed of recovery of glycogen reserves in m 'muscles and liver after physical exercise depends on the speed of receipt of carbohydrates in the body, such as carbohydrates, the timing for the reception of carbohydrates to the rest period.
To restore the glycogen reserves in m 'muscles after exhausting physical activity in eating rich carbohydrates to about 20 h, while the irrational food - even more. Correct timing of reception carbohydrate meal after an intense workout or competition promotes more efficient flow restoration of glycogen reserves. It is established that the admission of carbohydrates (50 m or more) after the larger loads (first 20 min), air associated with the manifestation of strength, and then every 2 h, leading to more rapid recovery of glycogen content in m ' muscles. More rapid glycogen resyntez muscles occurs when the consumption of glucose and sucrose (but not fructose) when using products with high glycolytic index.
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