Athletes and coaches are well aware of the importance of training to improve their performance, a little less they know what the nutritional aspect

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2 Athletes and coaches are well aware of the importance of training to improve their performance, a little less they know what the nutritional aspect can be a fundamental part of the preparation of an athlete. The energy will be in fact "tool" of the effort to which it must undergo, and as part of a diet, meaning organization quality and quantity of food intake, fluid balance is of utmost importance.

3 Rarely the athlete takes liquids according an appropriate strategy and not always drink the right amount and choose the appropriate time. Often expect to feel the sensation of thirst before rehydrate. Effective hydration, has a beneficial effect on performance and allows for a much quicker recovery, especially after intense efforts

4 Frequency and volume of fluids to drink depends on many factors: duration and intensity of exercise environmental conditions in which the exercise is carried out characteristics of the subject. The optimal strategy should be formulated on the basis of the type of effort, the sport, the type of commitment (amateur, competitive, professional) and the characteristics of the athlete.

5 HOW MUCH WATER IN OUR BODY?

6 A smaller percentage of water is present in women (52% compared to 57% of the adult male) and in the male obese (38% in the subject of 110 kg compared to 57% of a 60 Kg); fats, in fact, they contain little water, while the percentage contained in skeletal muscles is about 77%

7 The human body contains from 4% to 5% of electrolytes and mineral substances. Many of them participating in almost all metabolic processes in the body, their interest in the sport is mainly due to the metabolic role they play in muscle contraction (potassium, magnesium, sodium, calcium, phosphate) and functioning of the nervous system. Research shows the decrease in the level of performance in the sport, produced by alterations in electrolytes, especially when they are linked to significant losses of sweat.

8 The entrances and exits are always the same, the water balance must be in balance, with a minimum tolerance. The fine control of the concentration of body fluids occurs through the thirst center which in case of necessity stimulates the reflection of thirst and secretion of antidiuretic hormone (ADH or vasopressin). And 'wellknown fact the close relationship between urinary reduced and profuse sweating.

9 The intake of water is carried out for about 50% with the drinks, for the other 50% through the water component of the food solids (at least 60% of the weight of food eaten). There is also a small percentage of water that comes from the oxidative metabolic process, 0.6 ml of water per gram of carbohydrate, 1.9 ml per gram of fat and 0:44 ml per gram of protein. Water loss occurs through urine, feces, skin (sweat) and lungs

10 While remaining constant balance between revenues and expenses, the amount of fluid intake and missing vary depending on the product and the physical effort of the outdoor temperature.

11 The heat produced by muscular work must be partially dispersed, since the body works optimally only within a limited range of internal temperature of (t.rettale). The metabolic heat production during prolonged exercise, can increase by times than that of rest. In temperature rises by more than 1.5 C already lead to a considerable loss of capacity for physical and mental performance

12 The most effective and most used by the athlete in activity, is certainly that of the sweating with heat loss by evaporation, the other systems are significantly less effective. To this should be abundant sweats that seem to distort the appearance of the sport and who are the real responsible for the significant reduction of weight recorded by many athletes, especially after competition or training background.

13 Sweat does not cool the skin, it is the evaporation that cools. But we must not confuse with the evaporation of perspiration, which is responsible for the transition of the physical state of the temperature control - heat dispersion. If the external environment is too moist or ventilation is poor, the evaporation is hindered, the dispersion of heat, through this process, it becomes difficult or even impossible. The sweat glands continue to produce sweat in an attempt, not effective, to lower the body temperature, and as a result there is a progressive increase of the internal temperature with risk of hyperthermia, and an excessive loss of water and salts with dehydration.

14 L organismo cerca di disperdere calore attraverso la vasodilatazione cutanea e la sudorazione. La prima non rappresenta più il meccanismo di termoregolazione utile quando la temperatura esterna supera quella interna, la seconda perde di molto la sua utilità quando l umidità ambientale è elevata e quando è ostacolata da un vestiario eccessivo!!the body tries to disperse heat through skin vasodilation and sweating. The first no longer represents the mechanism of thermoregulation useful when the outdoor temperature exceeds the internal one, the second loses much of its utility when the ambient humidity is high, and when it is hampered by excessive clothes!!

15 You often see people wearing sports attire more suited to hiking in the mountains during the winter, with double layers of sweatshirts, raincoats and other strange hermetically sealed. The belief of many unwary is to lose weight more quickly, perhaps by training under the sun or in high humidity and little ventilation. More sudo and the greater the weight loss and substantially fat. It is wrong!!

16 A training run in a moist environment, not ventilated, wearing clothes that prevent proper air circulation at the skin surface, not only creates a false weight loss but can basically be harmful to health. The weight loss obtained by this method will be temporary and transient due for the most part to a excessive and unnecessary loss of fluids that will be recovered as soon as the individual will at the restitution of the same.

17 e real weight loss, there might be only when the intensity, exercise duration will be sufficient to allow us to use ored fats as energy substrates, in an airy, hydrating and wearing clothes that allow a correct air circulation.

18 Dehydration results in hypotension and reduced ability to sweat, so the evaporation process is stopped and there is a serious risk of hyperthermia. Excessive perspiration causes a progressive decrease of the circulating blood due to a decreased plasma volume, while it increases the demand for a more and more elevated cardiac output to meet the metabolic needs. The body then responds by increasing heart rate to offset the decrease in stroke volume and oxygen extraction by the tissues. This compensation will not last long, the subject will have to stop working in order to avoid heat stroke or even death if the body temperature exceeds 42 C

19 Dehydration due to fluid loss during exercise is a major problem for the athlete, the main symptoms are: sense of fatigue the thirst Headache Tachycardia dry mouth and kneaded dizziness asthenia muscle cramps dry skin restlessness difficulty concentrating decreased physical performance

20 Of fundamental importance during physical activity is also the homeostatic balance of mineral salts, necessary for the production of energy in the muscles and that contribute to delay the onset of the symptoms of fatigue. The ability of performance is, in fact, already greatly disturbed by small fluctuations in the balance of electrolytes. Reintegration of minerals it is however necessary only when the water loss is greater than 3 liters, in fact losses of sodium during physical activity are offset in part by the kidneys, that increasing the reabsorption reduce its elimination in the urine.

21 Unreliability of sense of thirst and hydration strategies Typically the athlete assumes spontaneously much less liquid than they lose. This is because the sensation of thirst, the main stimulus to the introduction of liquid, is often inaccurate and influenced by many factors, not least the psychological. The athlete must take drinks without waiting for the feeling of thirst, it must follow a pre-set level of hydration before, during and after exercise.

22 An abundant moisture provides better performance, but also the security of avoiding hyperthermia and other health hazards. The practice of taking a share of water before the race (pre-hydration) is very useful because it delays the onset of dehydration, increases sweating during physical activity and carries a lower increase in body temperature deep.

23 How much to drink? What the sportsman asks is that amount must take fluids and when. Obviously the amount of liquid required depends on how much sweat was eliminated during the exercise. Given the choice is always to be preferred overhydration rather than risk dehydration. It should be noted that overcoming the 600 ml / hour of liquid is over the threshold of intestinal absorption, it is useless then drink more.

24 The preparation for proper hydration of the athlete starts at least 24 hours before the performance. Two hours before exercise, so as to leave adequate time for the excretion of excess ingested water, you can drink about ml of water. During exercise early start to drink at regular intervals in order to calibrate the introduction with the loss of fluids through sweat, most people tolerate ml drinks every 20 minutes, always avoiding fructose.

25 The use of beverages with additions of carbohydrates and / or electrolytes is recommended only for exercise which exceed the duration of minutes. Below about minutes are not described significant differences in performance between the take drinks with carbohydrate-electrolyte or drinking water simple. During intense exercise that exceeds the duration of the hour, it is recommended to eat carbohydrates, 30 to 60 g / hour to maintain oxidation of carbohydrates and delay fatigue. Such a large amount of carbohydrates can be assumed in the drinks prepared in solution at 4-8% by drinking so ml / hour

26 Since most of the water losses during sporting activity takes place through the sweat that contains mainly sodium, a solution, to compensate for the loss of this electrolyte, it is to drink water with addition of salt in a concentration equal to that of sweat, ie about 3 g of salt in 1000 ml of water. The flavor is frankly debatable but can be improved with some flavor with lemon or orange. Are recommended foods rich in potassium (bananas, dried apricots). A glass of tomato juice or orange allows you to replenish lost electrolytes (potassium, calcium, magnesium) with 1,000 ml of sweat

27 Carbohydrates are sugars (glucose or sucrose) or starch (maltodextrin). Add sodium ( g / 1000 ml) in drinks consumed in exercise lasting more than one hour is recommended to improve the palatability, promote water retention and prevent hyponatremia may occur in some individuals who drink an excess of liquid.

28 In reintegrate losses drink about 500 ml of liquid for every kg lost 02.01, excluding alcohol and caffeinated. Tea and coffee, both of which contain caffeine, they are not recommended for athletes for their diuretic which can increase dehydration ; you possibly can consider the use of tea in very diluted form.

29 Recommendations of the American College of Sports Medicine eat a balanced diet and drink adequate amounts of fluids during the 24 hours preceding the sporting event, especially during the period that includes the meal prior to exercise, to promote proper hydration before exercise or competition drink about 500 ml of liquid two hours before the exercise, to promote adequate hydration and to give time for the excretion of any excess ingested water during exercise start drinking the top of the effort and continue at regular intervals, in order to use the liquid in an amount sufficient to replace all 'water lost through sweating or use the maximum amount that can be tolerated

30 liquids are ingested freshest room temperature (15-22 degrees c.) and flavored to enhance palatability and promote fluid replacement adding a right amount of carbohydrates and / or electrolytes to a solution replenish the liquids is recommended for sporting events lasting longer than one hour during intense exercise lasting more than an hour, it is recommended to ingest carbohydrates at a rate of grams. per hour to maintain oxidation of carbohydrates and delay fatigue. This frequency of intake of carbohydrates can be obtained without compromising the fluid distribution drinking 600/1200 ml of solution containing from 4% to 8% carbohydrates per 100 ml.