MINERALS FOR ACTIVE PEOPLE: IRON
October 24th, 2013 by André Gagnon, ND
Iron is the mineral that allows blood to transport oxygen. For athletes that must exert important physical efforts, the transportation of oxygen must be optimal; therefore the level of iron must also be. Any deficiency leads to an important decrease in performance levels. It then becomes essential to provide adequate amounts of iron depending on athletic practices.
Iron fills a particularly important role in the proper function of the body. It is a part of the constitution of hemoglobin contained in red blood cells and myoglobin found in muscles. These two components allow for both the transportation of oxygen, or energy, from the lungs and the evacuation of carbon dioxide gas. An athlete will see performance levels decrease significantly if deficient. Iron also plays a role in our immune system and protects against infections.
Our red blood cells have an average lifespan of 120 days. The iron contained in these cells is nonetheless recycled and reused. Even though this recycling decreases our overall need for iron, losses (perspiration, stools, urine, menstruations) must be compensated. Losses are equivalent to approximately 1 mg per day in sedentary persons, 2 to 3 times higher in athletic men and 2 to 5 times higher in athletic women.
These losses are accentuated in athletes due to many factors: premature death of red blood cells that have been weakened by increased effort and hyperthermia, the increased renewal rate of red blood cells, the increased speed of the digestive process (iron has less time to be absorbed) and dehydration. Certain illnesses may also influence the adequate absorption of iron such as Crohn’s disease and celiac disease.
Signs and consequences of iron deficiency:
- Decreased capacity for physical effort,
- Decreased oxygen transmission,
- Shortness of breath,
- Reduced intellectual capacity,
- Reduced resistance to infections,
- Muscle stiffness,
- Cold feet and hands,
- Drowsiness and irritability.
If iron seems readily available in our nutrition to compensate for losses, reality says otherwise. Studies have shown that levels of iron are insufficient due to the lack of minerals in our food. SUVIMAX (Supplémentation en Vitamines et Minéraux Antioxydants, 1994- 2002), a unique French study on the nutritional prevention of important health concerns and conducted over an 8 year period has shown particularly important deficiencies in women. 24 % of women have inferior iron intake levels, 4.4% of which have anemia, and 91 % of these women have levels inferior to recommendations. It is consequently important to choose foods rich in iron and adapted to our needs, particularly when practicing regular exercise or sports.
Tips for optimum assimilation
Foods containing tannins (coffee, tea, wine), calcium, a high quantity of dietary fibres or phytates (bran) decrease iron absorbency levels in the body by 60 to 70 %. Certain antacids, antibiotics and non-steroidal anti-inflammatory drugs, as well as calcium supplements, may hinder its assimilation.
However, certain foods help iron absorption when they are eaten at the same time. Foods that contain vitamin C play a role, as well as meats, fish and poultry. Eating these can increase absorption up to 4 times. It takes 4 to 6 months to re-establish iron reserves. Choose foods rich in iron on quiet days when physical activity is moderate.
Choose the right supplement
If iron supplements are required, liquid supplements are advantageous. Their assimilation is optimal but also because they do not cause constipation when compared to formulas in tablet form. Furthermore, they are perfect for mixing into shakes or smoothies.
A formula including vitamin C is also a judicious choice as it will facilitate iron assimilation. Local brands offer excellent quality products. Choosing a locally made product is not only a more affordable option but also more ecological.
Iron Status Alters Cognitive Functioning in Women During Reproductive Years, L. E. Murray-Kolb, K. E. Whitfield and J. E. Beard, Congrès de Biologie Experimentale, Washington, avril 2004.
Guide nutritionnel des sports d’endurance, 2e ed. Denis Riché, Vigot 2002
Médecine du sport, Jean-Marcel Ferret md, Henri Kaleckar md, Éditions Boiron 2000