Adequate intake of calcium and iron.
Insufficient supply of products that are a good source of protein carries the risk of nutritional deficiencies. And so, for example. limiting the consumption of meat products promotes iron deficiency, on the other hand, low consumption of milk and its products does not allow to ensure an adequate supply of calcium in the diet.
The results of research conducted among Polish athletes indicate, that iron deficiency affects approx 1/4 young players and 10% players, representing different sports, the deficiencies found are most often latent, while anemia is found rather rarely. One of the main causes of iron deficiency among athletes is insufficient consumption of this nutrient with food, which is especially true for young women. Below are methods that contribute to both increasing the supply of iron in the diet as well as improving its absorption in the gastrointestinal tract..
To increase the amount of iron in the body it is necessary:
• eat meat and fish regularly, best in combination with high-carbohydrate dishes (e.g.. spaghetti with meat). The heme iron contained in meat products supports the absorption of non-heme iron from plant products,
• include plant products with a relatively high iron content (cereals, dried fruits, legumes, vegetables with green leaves),
• eat plenty of vitamin C-rich fruits and vegetables (citrus fruits, black currant, Orange juice, parsley, pepper) because a diet rich in this vitamin increases the absorption of non-haem iron (from eggs and vegetable products),
Consuming large amounts of bran or strong tea interferes with the absorption of non-haem iron. Especially people with iron deficiency should consume it in moderate amounts or between meals.
You should also remember, that additional iron intake should only take place in cases of previously diagnosed deficiencies or prophylactically, but always after consulting a doctor.
Calcium is one of the most important macronutrients in the system. Almost the entire content of this element (99%) is located in the skeletal system and only 1% in the rest of the body. The results of many studies, conducted among young athletes as well as young people not practicing sports, often indicate that the intake of this mineral is too low. This is a worrying phenomenon, because insufficient calcium intake in the diets of young people prevents them from reaching high peak bone mass, which in the future favors the development of osteoporosis. Insufficient calcium intake is especially dangerous during the growth spurt, when bone growth is particularly intense and therefore the demand for this mineral is also relatively high. In addition, calcium plays an extremely important role during physical exertion, mainly in muscle conduction, both skeletal muscles and the heart muscle. Keeping calcium intake low for an extended period of time can interfere with these processes, negatively affecting the body's exercise capacity.
According to Polish nutrition standards, the daily requirement of calcium in young people aged 15-19 years is 1200 mg. Milk, cheese and all kinds of milk-based products are among the products that are the best source of well-absorbed calcium. To provide the recommended daily amount of calcium in dairy products, they should be planned several times a day, in amounts similar to these, shown in the table 8.4.
Table 8.4. Amount of dairy products covering the daily calcium requirement of adolescents 15-19 years (according to Ziemiański, 2001).
Thus, to increase your calcium intake in your diet you should:
• eat 3 times a day dairy products, in an amount at least 3 glasses of milk or 3 yoghurt containers. Young people, in the period of growth and maturation should consume together 4-5 glasses of milk a day,
• choose these dairy products, which contain a small amount of fat, because skim milk and cheese contain the same amount of calcium as full-fat products. It is also advisable, to consume dairy products with carbohydrate products (e.g.. corn flakes with milk). Yellow and blue cheeses are a very good source of calcium, however, due to their high fat content, they should be used in small amounts by athletes,
• small fish should be included in the athlete's diet, which are eaten together with bones (e.g.. sprats or sardines, smoked or canned) they are also a good source of calcium,
• in addition to animal products, plant products should also be included, which contain relatively much calcium. Soy products are a good source of this nutrient among plant-based products (degreased), as well as green spinach, dried figs, almonds and muesli flakes.