Ho Much Iron Do Athletes Need Per Day?


Iron Deficiency in Athletes

Iron deficiency is common in athletes. Nearly half of females who exercise may experience iron deficiency. [1] While females are at higher risk for iron deficiency due to monthly loss of blood with menstruation, male athletes can also suffer from it. The International Olympic Committee 2009 Consensus Statement on periodic health evaluation of elite athletes even recommended routine screening for iron deficiency. [2] Please note, unless otherwise specified, the term iron deficiency in this article solely refers to low iron and not resultant anemia, or low red blood cells. This article is also focused on adult athletes and the information discussed may not apply to children.


The first question to consider is why athletes are so susceptible to low iron. There are a bunch of theories, such as the idea that runners crush red blood cells with each footstrike. But it’s unclear that this really makes a big difference, and doesn’t explain why athletes in non-impact sports like cycling are also at risk. Gastrointestinal bleeding and blood in the urine are also possible sources of iron loss, but neither is particularly common among endurance athletes. Certainly, menstruation is a significant factor and is probably the main reason female athletes are at higher risk than men. You also lose some iron in sweat. And athletes may be more prone than most to have low levels of iron in their diets, either because they’re avoiding iron-rich foods like red meat or because they’re not getting enough calories overall.

It’s surprisingly difficult to nail down how much iron is enough. For non-athletes, doctors tend to look at how much hemoglobin you have in your blood. But that’s not a reliable marker for endurance athletes, because training increases your blood volume which in turn dilutes the concentration of hemoglobin. The more common marker for athletes is ferritin, which is the form in which iron is stored in the bone marrow, liver, and spleen for later use. There’s reasonable (but by no means unambiguous) evidence that if you’ve got normal hemoglobin but low ferritin, your athletic performance will be compromised.

What is iron? Why is iron important?

Iron is a mineral that has several important roles in the body including energy metabolism, oxygen transport, and acid-base balance. [3] Iron is found mostly within red blood cells and is therefore necessary for their production. Red blood cells transport oxygen throughout the body and are filled with proteins called hemoglobin. Each hemoglobin molecule contains iron. Oxygen picked up in the lungs binds to the iron inside hemoglobin and then is carried all over the body to supply oxygen to organs and tissues.

Where do we get iron from?

Iron comes from our diet. Dietary iron can be classified into heme iron and non-heme iron. Heme iron is found in meat, poultry, and fish. Red meat contains about three times as much iron as both poultry and fish making it one of the richest sources of dietary iron. Heme iron is absorbed by the digestive tract about twice as well as non-heme iron. Sources of non-heme iron include fruits, vegetables, and iron-fortified foods. Vitamin C assists with the absorption of non-heme iron in the digestive tract so mixing foods rich in vitamin C with non-heme iron-containing foods can increase the amount of iron the body absorbs.

Why are athletes at risk for iron deficiency?

Athletes need more iron than the general population. Iron is lost through sweat, skin, urine, the gastrointestinal (GI) tract, and menstruation. Exercise, particularly high intensity and endurance types, increases iron losses by as much as 70% when compared to sedentary populations. Athletes lose more iron due to heavy sweating as well as increased blood loss in the urine and GI tract.* Red blood cells also break down more quickly in those who exercise. The mechanical force of a footstrike during endurance running, for example, can increase the destruction of red blood cells in the feet, leading to a shorter red blood cell life span.

Female athletes are at even higher risk for iron deficiency as compared to males due to monthly blood loss associated with menstruation. Athletes may also be at risk for iron deficiency due to insufficient dietary iron intake. Remember, the body is not very effective at absorbing dietary iron. Athletes, particularly menstruating female endurance athletes, need to be extremely mindful of iron intake in order to meet their bodies’ demands. Those following a strict vegetarian or vegan diet can be at even higher risk for iron deficiency due to the decreased absorption of non-heme iron found in plants and fortified foods.

What are the symptoms of iron deficiency?

Because iron is necessary for oxygen transport and energy metabolism, both of which are critical for fueling aerobic exercise, endurance athletes can experience a decline in exercise capacity and VO2 max, the maximal amount of oxygen the body can use, with iron deficiency. As the iron deficiency becomes more severe, the body cannot make a sufficient number of red blood cells, and anemia, meaning low red blood cells, develops. Athletes with iron deficiency anemia will generally have more pronounced symptoms.


Trained athletes and clients alike are monitoring their intakes and percentages of critical fuels – carbohydrates, fats, and protein – but are potentially falling short on their micronutrient needs. These trace players in the diet can have a significant impact on overall performance. Athletes and clients are pumping plenty of iron in their training programs, but are they getting enough of this key mineral in their diet to reach the performance levels they are chasing?

Iron is just one example of a micromineral that has been shown to either decrease or improve endurance performance, depending on an athlete’s iron status (1,2,3).

But first! If you want more information on vitamins and minerals in supplement form, check out the NASM course on Making Sense of Supplements.


Iron plays an important role in energy metabolism. It is a critical component of hemoglobin and myoglobin, the two main proteins in charge of delivering oxygen to the body (4,5). Hemoglobin is found in red blood cells and facilitates the transfer of oxygen from the lungs to the body’s tissues. Myoglobin resides within muscle cells, and is responsible for intra-cellular O2 transport and temporary oxygen storage (4).

Iron also supports immunity and development as a component of proteins and enzymes that fight oxidative stress and help synthesize DNA, connective tissue, and some hormones (4,5).

The adult human body contains 3-4 grams of iron, most of which can be found in hemoglobin. The remainder is stored in the spleen, liver, bone marrow, and myoglobin, either in the form of ferritin or hemosiderin (4,5).


Having an iron deficiency, or in severe cases, anemia can be detrimental to athletic performance and overall health. It limits the body’s capacity to carry and deliver oxygen, thus stunting potential maximal oxygen uptake or work capacity. Poor iron status is also associated with higher blood lactate concentrations during exercise.

Oregon State’s Micronutrient Center describes three levels of severity in iron deficiency, which are described below. Iron status can be determined through a simple blood test analysis of serum ferritin and hemoglobin.

1. Storage Iron Depletion

Iron stores are depleted, but functioning iron is still intact. No declines in athletic performance or general health are noticed at this stage.

2. Early Functional Iron Deficiency

Hemoglobin levels will test normal, but serum ferritin is low (20-30 nanograms is considered deficient). Production of new red blood cells is impaired.

3. Iron-Deficiency Anemia (IDA)

Hemoglobin is compromised, and will appear low (<13g/dL in men, and <12g/dL in women). IDA is associated with fatigue and a reduced ability to do work. It is more common in athletes and chronic exercisers than in the general population consuming a mixed Western diet. Iron supplements are typically prescribed to treat IDA (2).


In general, people exhibiting the highest risk for iron deficiency and anemia are women, runners, and vegetarians. Much of their risk is associated with poor dietary iron intake and low daily caloric intake.

Runners and other trained athletes are at risk for sports-related anemia caused specifically by heavy training. Iron-depleting training effects include mechanical hemolysis (physical sheering of red blood cells often seen in runners), intestinal bleeding, hematuria (blood loss in the urine), and sweating. Heavy menstrual loss is an additional cause of negative iron balance in female athletes (2).


Athletes seeking hypoxic conditions to increase their red blood cell density (and enhance endurance performance) are at an …
It is suggested that athletes should check their iron status prior to altitude training, and improve their levels if necessary before undergoing hypoxic conditions. Anemic individuals, in particular, should consider iron supplements beforehand.

The recommended daily allowance (RDA) for iron seems to be sufficient at altitude since iron losses tend to enhance the mineral’s absorption (7). However, athletes attempting to increase their red blood cell count (even those with normal iron levels) may benefit from a supplement (2), particularly women, who are at higher risk than men for iron deficiency.

How Much Iron Do Young Athletes Need in an Everyday Diet?

Young athletes hear a lot about the importance of eating enough calories and drinking the right amount of fluids for their performance and growth.

Lean meats, dark meat from chicken or turkey (absorbed better than plant sources)
Beans, lentils, nuts, and sunflower seeds
Iron-fortified cereals: cold cereals and oatmeal
Green, leafy vegetables such as spinach and broccoli
Dried fruits such as raisins, apricots, and prunes

Animal sources of iron are better absorbed than plant sources.

Include citrus fruit or drink orange juice with iron-rich foods. Vitamin C enhances the absorption of iron.
Vitamin C-rich foods include red pepper, grapefruit, broccoli, and strawberries.
Avoid teas, coffees, and cocoa with meals (nutrients in these beverages decreases absorption).
If you feel your athlete is at risk for iron deficiency, talk to your doctor. Professional guidance from your pediatrician will help determine whether or not blood work to assess your athlete’s iron stores and/or risk of anemia is warranted.


Getting Enough Iron with a Healthy Diet

To increase your iron stores, you should consume a healthy diet that includes a wide variety of iron-containing foods. Foods contain two types of iron: heme iron is found in red meats, fish, and poultry, and non-heme iron is mostly from plant sources (enriched and whole grains, beans, nuts, and some vegetables and fruit) as well as eggs and dairy products. About 60% of the iron in meat is non-heme. Here are common dietary sources of iron.

How to Figure Out the
Iron Content With Food Labels

Figuring out the iron content of foods based on food labels is tricky.  Although iron requirements vary by age and gender (and pregnancy, athletic, and vegetarian status), the Nutrition Facts Table for foods only has one value for iron.

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