FOOD SUPPLEMENTS: WHAT THEY ARE AND WHAT THEY ARE FOR
In everyday life food supplements are specific products that help absorb substances such as macronutrients (carbohydrates and proteins) and micronutrients (salts or vitamins). According to dietetics and to Italian and European law, food supplements are considered a kind of food. They do not have healing properties and are recommended to people who suffer from lack of nutrients or have increased dietary requirements.
In the sports world, some of these substances (sports supplements) are rapidly absorbed products that provide nutrition to the body before, during and after physical exercise.
The most commonly used sports supplements among Nordic skiers are based on solid or liquid carbohydrates. They provide the body with energy:
• before physical exercise (they increase the carbohydrate stores in the body - the glycogen contained in muscles - or reduce the amount of stored carbohydrates used),
• during exercise (they prevent the exhaustion of the glycogen stores in the liver and muscles, which, at the very least, reduces efficiency),
• after exercise (they replenish the body’s energy stores (muscular glycogen) which have been reduced or exhausted during exercise).
Athletes often drink rehydrating drinks, which are designed to prevent dehydration and electrolytic unbalance by supplying the body with mineral salts.
DIET AND TRAINING BEFORE SPORTS COMPETITIONS
The aim of every Nordic skier is to start a race with full energy stores.
To achieve this, in the week before the race, many athletes use the ‘carbo-loading’ strategy. This technique, which became popular in the 1970s, consists in eating large quantities of rapidly absorbed carbohydrates (such as pasta, bread, rice and French toast) during the three or four days before a race.
This is not always to the athletes’ advantage. The most recent scientific studies contradict this belief.
To start a race with the highest energy levels, the first secret is to reduce the quantity of training, by skiing less and less intensely during the six days before the race. In this way the stored glycogen (i.e. stored sugar) is not touched and remains in the liver and muscles. Skiers will start the race with full energy stores.
The last meal before a race is important. To avoid mistakes (that could negatively affect performance levels and increase the feeling of fatigue) small quantities of easily absorbed carbohydrates (such as bread, pasta or French toast) should be eaten. Other than carbohydrates, the meals before races and long training sessions should include a small quantity of easily digestible proteins, such as those contained in lean cured meats (ham).
Eating large quantities of pasta or rice at breakfast on the day of a race (hoping it will increase glycogen concentration) has damaging effects because it raises insulin levels, leading to a crisis caused by the early depletion of energy.
HYDRATION: WHY DRINKING AT LOW TEMPERATURES IS IMPORTANT
In difficult climatic conditions, such as the sub-zero temperatures in cross-country skiing races, it is important to drink before, during and after physical exercise.
The stimulus to drink is weaker when it is cold, so liquid intake is reduced and the risk of dehydration is higher. For this reason, starting a race fully hydrated gives athletes an advantage. It is therefore important to drink regularly during the days before a race and not a large amount all at once.
During a race the body looses liquids and mineral salts, which should be replenished afterwards. Because of very cold climatic conditions, drinking hot drinks such as tea in the refreshment areas is a good idea. In these conditions, hot liquids are absorbed more rapidly and effectively by the body.
Athletes who fail to replenish the water and salts lost via sweating endanger their health and reduce their performance levels. The loss of 2% of body weight through the secretion of liquids leads to a 10-15% reduction in performance levels.
Dehydration is dangerous for a number of reasons. In a dehydrated body, sweating is blocked in order to save fluids, even at low temperatures. Not sweating leads to an increase in body temperature, which has negative effects on the body (as if it were boiling over). In a dehydrated body, it is more difficult for blood to circulate, which leads to an increased load on the heart. In extreme conditions, this can cause heart failure. For every litre of water lost the heart rate increases (by about 8 beats per minute), cardiac output decreases and the body’s internal temperature rises by 0.3°C. Other possible symptoms of dehydration are thirst, muscle cramps, general weakness, loss of body weight and of lucidity.
For these reasons athletes should keep constantly hydrated, before and after races or training sessions, in order to provide the body with the liquids and mineral salts required to obtain the best performance levels and to stay in good health.
ENERGY WATER BOTTLE: instructions
The ideal ‘energy water bottle’, suitable for before and after a race, must contain water, mineral salts and carbohydrates in order to keep the body properly hydrated and supply energy in small doses.
Not all drinks are suitable during physical exercise and it is best to choose the ones that are. It is important to drink as soon as warming up exercises are finished and before starting a race, taking into account the kind of race. Simply stated, the more soaked in sweat clothes are, the more it is important to drink. How much to take depends on the kind of drink. In theory, the more concentrated a drink is, the longer it will stay in the stomach, but a bloated stomach can be uncomfortable. Small quantities of water should be drunk regularly, e.g. during a 2-hour skiing session a small sip of liquid should be drunk every 20 minutes (or at intervals as close as possible to that). Before intense physical activity athletes can drink up to 150-200 ml - there is enough time to absorb that amount. Usually, during a competition, smaller quantities should be drunk.
Before and during a race, the gastric transit time of a drink is reduced if the concentration of sugars and mineral salts is below 4-5% (i.e. if their concentration is not too high). If the sugars are fructose and maltodextrins, the gastric transit time is shorter compared to a drink containing the same weight (in grams) of carbohydrates. If the drink contains too many carbohydrates, there is no flow of water from the gut to the blood - on the contrary, water is drawn into the intestinal lumen. In other words, there is a ‘theft of water’ and the drink does not bring any benefits.
During training sessions it may be necessary to drink a higher quantity of liquids compared to a race.
The perfect drink for post-intense exercise must provide water, minerals and a certain amount of carbohydrates, to replenish the exhausted or partly used energy reserves. Unless skiers are suffering from severe dehydration, it is not strictly necessary for them to drink liquids and mineral salts as soon as possible. Drinking carbohydrates (even plenty of them) increases the gastric transit time of drinks but it does help produce glycogen (the form in which carbohydrates are stored in the liver and muscles) that has been used by exercising muscles. This is an advantage, especially when races or training sessions take place very frequently.
GASTROINTESTINAL PROBLEMS: HOW TO EFFECTIVELY PREVENT THEM
Athletes practicing endurance sports, such as long-distance runners, cyclists and cross-country skiers, often suffer from problems in the upper and lower abdomen.
These problems can sometimes cause athletes to reduce the intensity of their exercise, to stop training and, in the most severe cases, to drop out of competitions.
A good, balanced diet or limiting the intake of certain foods 2-3 days before a race can reduce the risk of gastrointestinal problems during physical exercise. Foods with high fibre content (such as pulses and whole cereals) should be avoided twenty-four hours before a race. Fruit should be eaten in limited quantities. Likewise, milk, cream and ice cream (even small quantities), even if they do not normally have any side effects, should be avoided.
Coffee intake should be limited in the hours before a race.
The last meal should be eaten at least three hours before the beginning of a race (four if digestion is slow). The total intake of fats should be low, because fats are more difficult to digest. A long digestion means the organs involved in the process need a larger supply of blood, which cannot be used by exercising muscles.
RECOVERY: why, what and when
At the end of a long training session (lasting more than 75 minutes) or an intense session, the body has sweated and therefore lost water and mineral salts. Energy stores have been reduced (or exhausted) to deal with fatigue. Intense physical exercise can damage muscular fibres.
If the next training session is scheduled within the next 24-48 hours or if athletes want to be in perfect condition at the beginning of a race, they have to recover carefully, replenishing what the body has used to manage the exercise-related effort.
The most recent studies show that the body’s ability to replenish its glycogen stores is highest in the 30 minutes after exercising.
However, this process can occur most effectively only by supplying carbohydrates with a high glycemic index (such as glucose, sucrose and maltodextrins) because they are readily absorbed.
Repairing damaged muscular fibres requires branched-chain aminoacids. Aminoacids of this kind are called ‘essential’ because the body is unable to synthesize them and they have to be supplied through dietary sources.
Enervit offers the most effective solution to athletes who wish to recover without neglecting any details. Enervit R2 Sport is a powder containing mineral salts, carbohydrates with a high glycemic index, aminoacids and vitamins - the ideal solution to a speedy recovery. Enervit R2 Sport must be taken no later than 30 minutes after ending exercise. A single-dose bag (50 g) must be diluted in a water bottle (with at least 350 ml of water) and shaken very well.
In this way athletes are sure they are recovering the nutrients they lost in the speediest and most effective manner, preparing for the next session of exercise without neglecting any details.
NORDIC SKIING, INTEGRATION AND COLD
Skiing requires a certain amount of energy. Most of the energy used is turned into heat that, with the exception of what is needed to keep the body’s core temperature constant, must be dispersed. In other words, plenty of heat is produced and it is not true that athletes practicing sports in cold climates need extra energy to keep warm.
Skiers must use clothes to protect the body areas from which most heat is lost (such as hands and ears). However, cross-country skiers do not need a special diet just because they practice sport in very cold environments. Before starting physical activity, it is always a good idea to eat a jelly containing carbohydrates with a low glycemic index (fructose and isomaltulose), which will be absorbed and used by the muscles during a race. During the race, athletes must eat other solid carbohydrates (tablets with salts) or gels.
A difference between athletes practicing sports in hot and cold environments is that, in cold settings, it is not necessary to drink quite so much. However, drinking is necessary because even when exercising in a cold environment, a certain amount of sweat is produced and the body’s core temperature rises.
HUNGER ATTACK: management and prevention
Intensely practising a sport such as cross-country skiing should be done with as much stored energy as possible. In this kind of situation and sub-zero temperatures, the body makes a big effort and considerable amounts of energy are used. A correct diet enables cross-country skiers to have the right kind of ‘fuel’ available. To avoid being left without energy while exercising, it is important to carefully select the food (and the amount) to eat before starting an exercise session. The last meal before beginning should contain food with readily available sugars such as glucose or maltodextrins and with sugars such as fructose, which takes longer to absorb. The foods (or supplements) taken before beginning to exercise should be easy to digest and free from fibres and lactose.
To make energy stores last as long as possible, it is important to define an integration strategy before beginning to exercise. The kind of energy-rich foods and when to take them should be clearly defined. They should be taken before the stimulus to eat arises, in order to have energy available for a longer period of time and to extend maximum performance times.