Żelazo w diecie osoby uprawiającej sport
Olivia Davis
2026-03-21
5 min. czytania
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1 zdjęcie
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Fizyczne wysiłki wymagają zaangażowania wielu szlaków metabolicznych, które wymagają uczestnictwa określonych mikronutrientów, a ponadto, treningi mogą wzmocnić biochemiczne adaptacje mięśni, tym samym zwiększając zapotrzebowanie na niektóre mikronutrienty. Sportowcy, którzy często obciążają swoje ciało przez ograniczanie ilości spożywanej energii, stosują radykalne metody redukcji masy ciała, wykluczają składniki pokarmowe, mogą mieć niedobory niektórych mikroelementów. Jednym z najczęściej występujących niedoborów jest niedobór żelaza. Niedokrwistość z niedoboru żelaza występuje u 10–30% sportowców, częściej u kobiet niż u mężczyzn.
Tasks and body demand for iron
Iron is considered a trace element that is essential for the body to function properly. It is involved in numerous metabolic processes, including DNA synthesis, the formation of neurotransmitters and hormones. The amount of iron in the body depends on gender and age, being 4.2 g in adult men and 3.4 g in women. The requirement for iron in physically active women is significantly higher than the standard: it may be up to 70% higher compared to the average requirement (EAR). Individuals at risk of deficiency (e.g., long-distance runners, vegetarians) should undergo regular testing and follow an iron-rich diet that exceeds the norm (>18 mg for women; >8 mg for men). Iron deficiency can lead to disturbances in erythropoiesis, which can result in anemia. It is important to remember that disturbances in erythropoiesis may also have other nutritional causes or develop as a response to chronic diseases, so any deviations from the norm should be discussed with a doctor. Even with a balanced diet and normal production of red blood cells, anemia can develop due to a rapid loss of red blood cells (e.g., through their degeneration or bleeding). In cases of iron deficiency, symptoms such as thinning of the tongue and smoothing of its surface, dry skin, cracks in the corners of the mouth, brittle hair, brittle nails, and the appearance of longitudinal ridges may occur.
Effects of iron deficiency on health and physical capacity
Lack of iron can lead to negative health effects and a decrease in physical capacity, including impairments in muscle tissue function and decreased physical fitness, which in turn affect workout adaptation and outcomes. High-intensity physical activity, menstrual bleeding, mechanical hemolysis, and gastrointestinal micro-bleeding can disrupt iron metabolism. Athletes with iron deficiency should seek help from specialists and consider oral supplementation and changes in diet. It is important to note that taking iron immediately after physical activity is not recommended due to an increase in hepcidin levels, which disrupts iron absorption. The return to full health can take from 3 to 6 months. Athletes with previous anemia episodes and iron deficiency (low ferritin levels) should use dietary strategies to increase their iron levels. It is best to take highly bioavailable iron, such as heme iron, or non-heme iron in combination with vitamin C. A common phenomenon among athletes is the temporary decrease in hemoglobin levels, which appears in the early stages of training and is associated with the so-called hemolysis, or sports anemia. These changes can be beneficial during aerobic efforts and do not have to negatively affect physical capacity.
The process of iron absorption in the body
Iron in foodstuffs is present in two forms: heme iron (Fe2+) is found in animal-derived products and also in the form of iron ions, while non-heme iron (Fe3+) is present in plant-based products. Each of these forms is absorbed in varying quantities – it is estimated that heme iron is absorbed at around 25%, while non-heme iron is absorbed at 2-5%. It is believed that heme iron is directly transported into the cell by binding to a specific transporter. However, iron in the form of Fe3+ ions must first be reduced to Fe2+ before it can be transported from the digestive system into the enterocytes. This is achieved through the enzyme ferroreduktase in the presence of ascorbic acid. The subsequent fate of iron depends on the body's current requirement and the amount of iron in the body. Iron can be stored in the cell by binding to ferritin, or it can be oxidized to Fe3+ and enter the circulation, where it binds to another transport protein and is delivered to target organs such as bone marrow and liver.
Nutritional recommendations for anemia
Substances that enhance iron absorption include vitamin C, peptides from partially digested muscle tissue, fermented foods, as well as organic acids such as apples or citric acid and fructose (honey). Iron-inhibiting products include: phytanies (plant-based products), peaches, polyphenols (black tea and coffee), peptides from partially digested plant proteins, peptides. General recommendations for optimum iron requirements for athletes also include adequate energy intake, especially among athletes with a low iron intake index, as they suffer from low iron content in grains, soybeans, soya beans, grapefruit juices, fruits and vegetables, and at least five times a week the benefits of these products are to be supplied in the form of cereals, grains or cereals (fruits, grapes, legumes, fruits, vegetables etc.).
Summary
Anemia associated with iron deficiency is a very common phenomenon, especially among groups such as: adolescents in the developmental period, individuals on a reduction diet, those with a monotonous diet, individuals who consume high amounts of fiber and rarely consume meat products, athletes who are subjected to intense loads during training. Proper procedure, including causative therapy (following an appropriate diet or taking iron supplements after medical consultation) helps restore the correct parameters.
