Basic needs of the athlete

The expenditure of the body during exercise
The sports activity involves spending two orders for the body: energy and water.

Energy expenditure. A person who induces or engages in a sport may spend up to three times more energy than at rest. Its power is of paramount importance since it provides, among others, three energy nutrients: proteins, carbohydrates and lipids.

This is - by far - the carbs that provide the most energy to the sports they represent 50 to 60% of total energy intake required by the body active. Lipid requirements are of the order of 15 to 25% and protein range between 15 and 20%. (These proportions may vary from one individual to another and according to the sport practiced.)

In general, when trains extensively, especially the body uses carbohydrates as an energy basis. Conversely, if the drive is moderate and lasts longer, the body will be more reserve fats (lipids). But beware: it is not a question of weight loss, but rather an energy expenditure.
It goes without saying that the energy requirements vary from one individual to another, and more dependent on the type of exercise performed, its intensity and its duration.

The water expenses. Physical exercise results in a significant production of heat, so a rise in body temperature.

To prevent overheating, the body then dissipates excess heat mainly through sweat, which is composed of 99% water and 1% salt. Alone sweating is responsible for more than 80% loss of body fluid during training.

During a period of long duration, can lose two to three liters of water by the evaporation of sweat. Since blood - like the whole body for that matter - is composed of 70% water, fluid loss decreases the amount of blood in the body and slows down the transmission of energy to the muscle. In addition, the loss of water disrupts the thermoregulation of the body less water means less sweat, thus a slower evacuation of heat.

Therefore dehydration watches sports neglecting to drink enough. At last, if the athlete continues to "push the machine" without hydration, his body will reduce the production of sweat to keep its water reserves. His body temperature will rise and if it exceeds 41 degrees Celsius, it will heat stroke.

The physiological needs before exercise
When and what to eat? It has been scientifically demonstrated that the performance is better when physical activity is preceded by a meal occurs when fasting. Nevertheless, requires comfort, better avoid the digestive system is at work at the time of sport. So it is best to eat three to four hours before activity. The fats (lipids) putting six to nine hours to be digested, it must consume more well in advance.

The muscles during exercise primarily needs carbohydrates. To fill these nutrients be chosen grain foods that contain them in large numbers and are more easily absorbed by the body: Pasta made from full grain, rice cakes, semolina, bread, granola low type bar fat, etc. If there is less than two hours, opt for fruit, a mixture of nuts and dried fruit as well as fruit or vegetable juices, which contain carbohydrates quickly assimilated by the body.

The fats - or lipids - occupy an important place in the diet of the athlete, because they provide energy, fat-soluble vitamins (that is to say soluble in fat, such as vitamins A, D and E ), as well as essential fatty acids. The contribution of the fat should not be below 15% of the overall energy.
Protein requirements for energy themselves are much smaller: they represent about 2% of energy intake. Because they put more or less four hours to be digested, especially their role will be to stave off hunger during exercise.

As pointed out by the Canadian Association entraîneurs2 a meal or snack before exercise should, in general:

provide enough fluids to ensure hydration;
be low in fat and fiber material to facilitate gastric emptying and minimize gastrointestinal discomfort;

be rich in carbohydrates to maintain blood glucose levels;
have a moderate protein content;
be composed of familiar foods and well tolerated.

It should also stress this last point: the individual needs differ from one person to another and it is up to the athlete to find what suits them best to optimize its performance.
When and what to drink? Two hours before exercise, athletes should take 400-600 ml (14-22 ounces) of water, juice or energy drink containing between 4 and 8% carbohydrate. Then, 10 minutes before, it is recommended to drink again between 125 and 250 ml.
Warm up gently. The role of the heating is the manufacture of heat to increase the efficiency of chemical reactions in the muscle cells and dilate blood vessels which can thus permit a greater flow of blood to the muscles.

Similarly, the heating prevents muscle injuries, since muscle is heated up to 20% more flexible than when it is "cold".
Another important advantage of the heat: it gradually prepares the heart to face sustained efforts.
Warming up is the opposite of run out. This is why intensive efforts - such as sit-ups, push ups (or brachial adjustments) and sprints - are not seen as warm-up exercises.

Rather go smoothly, opting for a combination of light exercise that gradually will raise the blood pulse and body temperature: jumping on the spot, making the low-speed bike, perform jumps with simultaneous lateral deviation of the arms and legs (Jumping Jack), walk trot, etc.

The duration of heating depends on the length and intensity of the activity that follows.
Stretching: caution! The recherches1 tend to show that stretching immediately before exercise made have no effect on injury prevention. In addition, they reduce certain types of performance, such as jumping.

It is important here to distinguish the cold stretching performed those we practice regularly.
It is therefore strongly advised to perform, without overheating, sudden and too pronounced stretching, as they may damage the muscles and tendons instead of preparing them to function better.
Also, like physical exercise performed on a regular basis, stretching sessions performed over several weeks could improve performance and prevent injury, according to some scientists.

Needs during exercise
Nutrient consumption during exercise is to replace fluid loss and to provide sufficient carbohydrates to keep glucose levels in the blood.
This is especially important if you perform an endurance activity that takes place in extreme conditions (heat, cold or altitude).

Generally, it is not necessary to drink during a period of less than 30 minutes. Furthermore, for an effort that will stretch of 30 to 60 minutes, drink 125 to 250 ml of fluid every 15 to 20 minutes. In hot and humid weather, it is best to start drinking early in the activity and then drink at a higher frequency, as required.

During a sporting activity lasting longer than 60 minutes, so do not wait until thirsty to drink. The liquid absorption will both to hydrate to supply sugar and compensate the loss of minerals removed by sweat. To do this, we may use a slightly sweetened water containing some salt or a sweet drink. In this regard, it is preferable to search for beverages containing less than 100 grams of sugar per liter, so that the digestive system absorbs more quickly.

Marathon runners and hiking Cyclists can recharge their energy by eating bars, fruit or juice, also in small quantities and on a regular basis.

To avoid stomach cramps, avoid anything containing gas: in training, the stomach is hot and the gas therein are expanding. They then create a pressure. Moreover, a too cold liquid may also cause cramps, since under the action of cold, stomach shrinks. A fresh liquid is recommended.
It is important to indicate that for a medium effort or long-term, there is no "one rule" about the water and energy needs. In such circumstances, it must be drunk on its own water and energy losses, and according to his own tastes.

The needs after exercise
What to eat and how much? After exercise, it must provide sufficient energy and carbohydrates to restore muscle glycogen and ensure rapid recovery of muscles. If exercise has depleted glycogen, a carbohydrate intake of 1.5 g / kg body weight during the first 30 minutes and then every two hours for four to six hours, enough to the restaurer2.
Indeed, during the first 30 minutes following prolonged exercise, the body seeks to rebuild its reserves as quickly as possible and to regenerate. Insulin - an anabolic hormone by entering glucose from the blood into the cells - is then "out of stock" and begs to quickly reap carbohydrates and proteins.

Among the products that meet the nutrition and energy deficits include fruit yogurts, cereals, bananas, vegetable juice, crackers, cheese, energy bars and drinks.
What to drink and how much? To overcome the shortage of water and salts that causes prolonged activity, it may be necessary to drink up to 1.5 liters of fluid for every kilogram of body weight lost after exercise. A sweet drink will fill those needs and allow the athlete to redo its glycogen stores. Drinks containing caffeine and alcoholic or carbonated beverages should be avoided. To know if we have enough to drink, it may rely on the color of her urine: if it is again clear, hydration is complete.
Stretching carefully. Stretching performed after training are deemed to provide a beneficial effect on the muscles and tendons, but the scientific evidence remain to be demonstrated in this regard. It is generally accepted that stretching performed on a regular basis would help strengthen the muscles and ultimately improve performance.

Cool. When completing a physical activity, it is best to slow down the bodily activity for a few minutes by walking and breathing deeply. This accelerates the discharge of the accumulated lactic acid in the muscles, while relaxing the cardiovascular system.