It is well known that as a runner you must have enough iron in your body. Iron is essential for the transport of oxygen. Oxygen that our muscles need to be able to run (very) fast. Getting enough iron from your diet is not always easy. We help you on your way.
A certain diet, increased consumption, blood loss or genetic factors can cause your iron concentration in your blood to be too low. You will notice this if efforts start to take more effort, you start to see paler and/or you experience dizziness, for example. If an iron deficiency has actually been determined by means of a blood test, you can do two things: ensure that you get more iron from your diet or take extra iron. How you then ensure that you absorb that iron optimally – according to the most recent knowledge – we will explain in detail below.
Iron intake from food
Iron comes in two varieties. Heme iron is only found in animal products, non-heme iron in plant and animal products. Our body is better able to absorb heme iron than non-heme iron. So it is easier for your body to absorb the iron from red meat, fish (especially anchovies, mussels and oysters) and eggs than the iron from, for example, spinach, dried fruit and apple syrup. Fortunately, our body can also adapt well. The moment your iron status is lower, your body will do its best and actually absorb more iron. If you want to take in more iron through your diet, then you regularly opt for iron-rich products. Products that contain a lot of iron (per serving) include whole grains, rye bread, muesli, parsley, lamb’s lettuce, purslane, potatoes, all legumes, red meat, oysters, anchovies, mussels, eggs, seeds, nuts and dried fruit. Also apple syrup (note that iron lactate has been added).
Iron is also often added to meat substitutes, just like certain breakfast cereals. These snacks and meals provide a large share of your daily required amount of iron.
Iron intake from food
Your iron status is not only determined by how much iron you get through your diet. At least as important is what your body does to it afterwards. In other words, how much is included. The body absorbs about 25% of heme iron, and a maximum of 10% of non-heme iron. We know that a number of substances cause a reduced absorption. This concerns calcium (in combination with heme iron) and polyphenols that you find in green and black tea, in coffee and in wine. If you eat iron-rich animal products, you would rather not eat dairy or eggs, for example. Plant-based dairy also falls under this category. This is because extra calcium is often added. Just like products made from soy. In spinach, also rich in calcium, the high proportion of vitamin C ensures that we can absorb the iron from it reasonably well. Because vitamin C actually improves the absorption of iron.
If you combine iron-rich products, for example with a kiwi, orange, Brussels sprouts or bell pepper, your body can absorb more iron. Even if you have a deficiency of vitamin B12 or folic acid or if there is an infection, your body will be less able to absorb iron.
Iron supplementation
If your iron is so low that something has to change quickly, or if you are unable to take in enough iron through food, your doctor can prescribe a supplement. Never just take a (high-dose) supplement on your own. Iron can also be toxic to the body in large quantities.
When you start taking extra iron, it is smart to time the intake well around your training. The absorption of iron is strongly influenced by the hormone hepcidin. More hepcidin leads to a reduced absorption of iron. This hormone fluctuates throughout the day. A workout has a lot of influence on the presence of hepcidin. For example, the concentration of this hormone drops after a workout and then increases considerably in the 3-6 hours afterwards. Energy deficiency (and a lack of carbohydrates) causes a further increase in hepcidin. If you train in the morning, you prefer to take your supplement before your training, IMMEDIATELY after or only at the end of the day. If you train in the afternoon, it is better to start your day with a supplement. Sometimes an iron supplement can cause gastrointestinal complaints and constipation. If this is the case with you, you want to combine your supplement with sufficient fluids and something high-fiber fruit such as a pear, kiwi or pineapple. Research shows that it is better to take a good dose once a day (for example 200 mg) than to divide it over two moments.
If you want to read more about this, this is a good overview article: BRON